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URE'S DICTIONARY
OF
ARTS, MANUFACTURES, AND MINES
VOL. U
LOITDOV :
raxKTiB BT sromswooss xin> co.
irXW-STBKBT aQVAftI,
".TV
\
URE'S DICTIONARY
OP
ARTS, MANUFACTURES, AND MINES
oomAnmra
A CLEAR EXPOSITION OF THEIR PRINCIPLES AND PRACTICE
EDITED BY ROBERT HUNT, F.R.S. F.S.S.
Keep«r of Miidiig Beoords
Fonnerlj PxofiMaor of FbyiioB, GorenmiflDt School of lUiiflt, fte. fte.
AMiBTSD HT avMMwiM oonMXBVtoaB XHxvun nr aoxBVGi m> vaxiuib wna UAMuwAxmvna
Olvftzated with nMurly Two Thouaiid BagraTiagi oa Wood
Fifth Editiov, chietlt Rswbitten akd obsatlt Enlarobd
IN THBEB VOLUMES— VOL, II
LONDON
LONGMAN, GEBEN, LONGMAN, AND EOBEBTS
1860
ne riffhi qf Uraiul4MHoH w rmeroeA
ERRATA.
VOL. I.
•f
Page S. ACBTATB. flnt line, for '* by " read " In.'
ACETIC ACID, fUteenth Hdo, for ** Vanqoelln," rMd ** VaaqueUn."
„ IS. », fourth line bom bottom, for '* of soda aod acetone," read " of lime,** Ac
„ la. „ thirteenth line, for " one half of the sulphate of lime,** read " one half of tho
acetate."
„ 64. ALCOHOLOMBTRY, the last paragraph of the article Is Incorrect. ** The duties on Scotch
and Irish sphriU are equalised."
., 99. There Is an error in the sutement as It stands respecting Dentists' Alloy. The best authority
on this subject writes : ** In reply to your Inquiry, I have much pleasure in informing you
that I6-carat gold, which is | fine gold and | ^loy, the alloy being nearly always equal
portions of i iWer and copper, is not In the slightest degree injurious for dentists' purposes."
„ 146. AlfVONIUM, Chloride of, in the formula, for " NHs,*' read " NH*."
„ IS6. ARSENIOUS ACID, last lines, occurs this passage: ** Considerable discussion has arisen
from a statement made by "Ur. A. S. Taylor, that the arsenic employed in paper-hangings
was volatilised, Ac." It should read, ** from a statement made by Dr. A, S. Taylor, that
the arsenic employed in paper-hangings was remoTed, Ac.** Dr. Taylor assures the
editor that he never sanctioned the idea of Tolatilisation of the arsenical green.
,. MS. AZOBBNZOIDB. Dele " See Hydrobenxamlde."
„ S8S. BEER, fourth line from bottom, for ** Banerstock," read " Baverstock."
VOL. II.
„ 286. FORMIC ACID, for " its formuU Is CSHG^, Ac," read '« C'HO."
„ 82S. GAULTHBRIA OIL. Dele " which see."
,. 423. GUANO, paragraph 20, for « 3. Soda lime fi)r platinum,** read ** Bichloride of platinum."
„ 489. ICE-HOUSE, ninth line, for •* Fig. 964," read **F\(g. 985."
„ 519. Insert the initials E. S. at the end of Indigo.
,, 70a LEUCOLINE, for " a compound, ftc," read " a synonym of LEUKOL."
DICTIONAEY
or
AETS, MANUFACTUEES, AND MINES.
D
DAG0ERREOTTPE. A photographic process discoyered by M. Dagaerre, a
celebrated French dioramic painter, and published in July, 1839 ; the French
Government having secured a pension for life of 6000 francs on M. Dagaerre, and of
4000 francs on M. Isidore Niepoe, the son of M. Nicephore Niepce, who had for
some time been associated with Daguerre in carrying forward the experiments which
led to M. Dagaerre*s discoyery.
It is rendered clear fh>m some of Niepoe's letters, that he had abandoned all hope
of succeeding with iodine, upon which the sensibility of the Daguerreotype plate
entirely depends. In a letter to Dagnerre, Niepce says, ** I repeat it, sir, I do not see
that we can hope to derive any advantage fh>m this process — the use of iodine — more
than from any other method which depends on the use of metallic oxides i " and in
another he writes, ** A decoction of thiaspi (shepherd's purse), fumes of phosphorus,
and particularly of sulphur, as acting on silver in the same way as iodine, and caloric,
produce the same effect by oxidising the metal, for from this cause proceeded in
all these instances their extreme nMibility to light," Niepce died in July, 1833.
Dagnerre proceeded with his experiments for nearly six years, before he succeeded
in producing the desired results. The Daguerreotype process depends on the pro-
duction of a very delicate chemical compound of iodine and silver, on the surface of
a carefully preptured silver-plate. This compound is chemically changed by the ra-
diations proceeding from any external object illuminated by the sun. The image is
developed by the action of mercurial vapour, and lasUy rendered permanent, as fiir
as the action of light is concerned, by dissolving off the iodide of silver, by hyposul-
phite of soda. According to the first published description by l^guerre, the process
is divided into five-operations. The first consists in polishing and cleaning the silver
snrfiice^ by friction, with cotton fleece imbued with olive oil, upon the plate previously
dusted over with very finely-ground dry piunicestone out of a muslin bag. The hand
of the operator should be moved round in circles of various dimensions. The plates
should be laid upon a sheet of paper solidly supported. The pumice must be ground
to an impalpable powder upon a porphyry slab with water, and then dried. The surface
is next to be rubbed with a dossil of cotton, slightly moistened with nitric acid, diluted
with sixteen parts of water, by applying the tuft to the mouth of the phial of acid,
and inverting it for a moment. Two or three such dossils should be used in suc-
cession. The plate is lastly to be sprinkled with pumice powder or Venetian tripoli,
and rubbed clean with cotton.
The plate is then placed in a wire fWime, with the silver sur&ce uppermost, over a
spirit lamp, meanwhile moving it so as to act equally on every part of the plate. In
about five minutes a whitish coating will indicate that this operation is completed.
The plate must now be laid upon a flat metal or marble slab to cool it quickly. The
white surface is to be brightened by rubbing it with cotton and pumice powder. It
must be once more nibbed with the cotton imbued with acid, and afterwards dried by
friction with cotton and pumice ; avoiding to touch the plate with the fingers, or with the
part of the cotton held in them, or to breathe upon the plate, since spots would thereby
Vol. IL B
2 DAGUEBREOTYI'E.
be produced. After cleaning with cotton alone, the plate is ready for the next
operation.
The second stage is that of iodising the plate ; a box is prepared, having iodine
strewed over its bottom, and the silver plate, face downwards, is placed a few inches
above the iodine, and the lid of the box being closed, all is left at rest for a short
time. The plate most be left in this position till the surface of the silver acquires a
fine golden hue, caused by the vapours of the iodine rising and condensing upon it ;
but it should not be allowed to assume a violet tint The room should be darkened,
and no heat should be employed. When the box is in constant use it gets impreg-
nated with iodine, and acts more uniformly and rapidly ; but in general states of the
atmospheric temperature this operation will be effected in about twenty minutes. If
the purple colour be produced, the plate must be repolished, and the whole process
repeated-
The plate with its golden hue is to be introduced with its ftvne to the camera
obscura. During this transfer the light must not be suffered to strike upon the
surface of the plate ; on which account, the camera obscura may be lighted briefly
with a small wax taper.
The plate is now submitted to the third operation, that of the camera obscura, and
with the least possible delay. The action of this machine is obviously quicker the
brighter the light which acts upon it ; and more correct, according as the focus is
previously accurately adjusted to the place of the plate, by moving backwards and
forwards a roughened pane of glass, till the focal point be found ; and the plate is to
be inserted precisely there. This apparatus exactly replaces the ground glass. While
the prepared plate is being fastened, the camera must be closed. The plate is now in
a proper position to receive and retain the impression of the image of the objects
presented the moment that the camera is opened. Experience alone can teach the
proper length of time for submitting the plate to the concentrated rays of light ; be-
cause that time varies with the climate, the seasons, and the time of day. More time
should not be allowed to pass than what is necessary for fixing a distinct impression,
because the parts meant to be clear would be apt to become clouded. The impression
of the image of nature is now actually made upon the plate ; but it is as yet invisible;
and it is only after a lapse of several minutes, during which it is exposed to mereorial
vapour, that faint tracings of the objects begin to be seen.
The fourth is the operation with quicksilver, which must follow as soon as possible
the completion of the third. Here a phial of quicksilver, a spirit lamp, and a glass
funnel with a long neck, are required. The funnel is used for pouring the mercury
into a cup, placed in the bottom of an apparatus which will allow of uie application
of heat. No daylight must be admitted to the mercury box, a small taper only being
used to examine, from time to time, the effects. The plate with the dormant image
is placed some distance above the mercury, which vaporising, evokes in a truly
magical manner, the delicate lines which the solar pencil has traced.
After each operation, the interior of the apparatus, and the black board or fVame
should be carefully wiped, in order to remove every particle of mercury. The
picture may now be inspected in a feeble light, to see how far the process has suc-
ceeded. The plate, freed ftx>m the metallic bands, is to be placed in a box, provided
with a cover and grooves, to exclude the light, till it is made to undergo the last
operation. For the fifth and last operation the following articles are now required : —
strong brine, or a weak solution of hyposulphite of soda ; two troughs of tin plate, and
a jug of distilled water. The object of this process is to fix the photographic picture.
One of the troughs is to bo filled with brine to the depth of an inch, and the other
with pure water, both liquids being heated somewhat under the boiling point The
solution of hyposulphite of soda is preferable, and does not need to be warm. The
plate is to be first immersed in the pure water for a moment and transferred imme-
diately to the saline solution, and moved to and fro in it to equalise the action of the
liquor. Whenever the yellow tint of the iodine is removed, the plate is to be lifted
out by the edges, and dipped straightway in the water-trough. The plate, when
lifted out of the water-trough, is to be placed immediately on an inclined plane : and
without allowing it time to dry, is to be fioated over with the hot distilled water fW>m
the top, so as to carry off all the saline matter. As the quicksilver which traces the
images will not bear touching, the silvered plate should be secured by a cover of glass,
made tight at the edges by pasting paper round them.
The Daguerreotype process as thus published, although even then an exceedingly
beautiful process, was not sufficiently sensitive to enable the operator to obtain
portraits from the life. A period of twenty minutes was required even with the
most favourable light to produce the desired effect Numerous modifications were
speedily introduced, and many of them were patented.
The progressive advance of this branch of the photographic art, though of great
DAGUERREOTYPE. 3
intemt, oaoot be direlt on id Ihii place. Thove irfao we intnoted in tlie inquiry,
■rill find the information folly detailed in Hunt'i Manual of Photography, 31b Edition,
1857. It will be anSeieat in this work to detail cbe more important improvemenu
which bare become generally adopted. The SrtI Advance of real importance wu
made bj Hr. Towaon, of Devonport, «ho hai aince that time diltiDguuhed himaelf
by the inlrodnction of bia ijium of Great Circle Sailinff. Hr. Towaon anggeited the
lue of enlarged leniea, and by acting with luch. Dr. Draper, of New York, wai the
fint to procare a portrait from the life. Still thii was a tedioui proceai, but in IS40,
Mr. Goddard propowd the nae of bromide of iodine, by which infiuilelj iocreased
s:;iiaibilily waa obtained. ?rom that time the Daguerreotype waa generally employed
fbr portraitnre, nntil the Ikcilitiea of the collodion procea droTe it from Che field.
The imprOTed manipnlalion'now reaoliei ilcelf into
Carefnllj poliibing the ailrer plate after tome of the methods previotuly deicribed,
and the application finally of the hi^eat polish by the nie of a buffer, the beat form
being that employed hj H. Claadet.
In a box od a roller, to which (here it a haiidle,j!^ eSS, is placed a long piece of
drab-colonred Telvet, which can be drawn ont and extended by meant of a tecotkd
roller upon a perfectly flat table. The first foot or two, for example, it drawn oat i
the plate which hai already receivtd its preliminary polishing ii placed face down-
wards, and being pressed close with the Bngen, a npid circular molion it given to it,
and in a few minnles it receives its highest lustre. As Ihr Telvet becomes blackened
by use, it is rolled tsS, the portion remaining in the box being always perfectly clean
nnd ready for use.
The iodtnng process follows : and for this parpote a box dmllar K
will be (bond to be very aon*enient, (Jig. 639). g^
This iodisiDg apparatus consitit of a square box
with a closely fltling coTer o, &lse sides are
placed at an angle with Ibis box. a enp u at the
bottom conluDs the iodine, which it eOTered
thin game scteeo
wbich confines the iodine when it is not required
for the plate; this diriding the box into two
parta, n B, and k k. the former being always full
of iodine Taponr. When it is desired (o iodise
a plate, the cover c is removed, the silver plate
it placed at E, and the cover a closed.
The plate ia thus placed in the iodine box
ontjl it acquires a fine straw yellow colour. In
another box it placed either bromine or some
one of the many accelerating fluids. If bro-
mine, or any bromide ia employed, tho plate
sbDold remain until il becomes of a rote colour.
As a general rule, if tbe yellow colour produced
by iodine be pole, the red should be pale also ; if deep, the red mntt incline to violet-
The proper lime for exposing a plate to any of those chemical lubalauGet which are
destined to practice the sensitive film, must vary with the temperature, and it can
ouly be determined by experience. The sensitive plate is now removed to the
camera obacnra, for a description of which see Photoobapbt. It is scarcely neeet-
sary to tay, thai the plate must be preserved in perfect darkness oulil exposed to
the image in the camera. A few seconds when the plate is properly prepared will
be found amply tnfficient to produce the best effect.
The impression must be developed in the mercury box (,fig. MO) in the manner
described by Dagnerre. This mercurial box consists of a box mounted on legi,
having a close fitting cover a, and an iron bottom in which i« placed the mercnry c.
DAMASCUS BLADES.
and a small thennometer f tx> indicate the proper temperature, g is a piece of glass
g^Q let into Uie side of the box through which the
Daguerreotype plate h fixed in the frame b can
be seen, d is a spirit-lamp, and i the platform
on which it stands. The subject is eventually
fixed by the ose of hyposulphite of soda, which
removes the bromo-iodidc of silver and leaves
a picture produced by the contrast between
a combination of the silver and mercury, and
the surface of the unchanged polished silver.
The application of chloride of gold to the
finished pictare was introduced by M. Fixeao.
Chloride of gold applied to the picture has
the e£Pect of fixing and enlivening the tints. A
small grate being fibced by a clamp to the edge
of a table, the plate is laid upon it with the image
uppermost, and overspread evenly with solution
of chloride of gold, by means of a fine broad
camel hair brush, without letting any drop over
the edge. A spirit lamp is now brought under
the plate, and moved to and fro till a number
of small steam bubbles appear upon the image.
The spirit lamp must be immediately withdrawn.
The remainder of the chloride solution must be
poured back into the phial , to be used on another
occasion. It is lastly to be washed and exa*
mined. This operation has been repeated three
or four times with the happiest effect of giving
fixity and force to the picture. It may then
be wiped with cotton without injury. The process of colourmg these pictures is a
purely artificial one, which, while it destroys the beauty of the photograph, does not
m any way improve it as a picture.
Daauerreotype Engraving. — Several processes for etching the Daguerreotjrpe plate
were introduced with more or less success. Professor Grove produced a few good
engravings by the action of voltaic electricity. Berard and Becquerel were also
enabled to produce some promising results by a similar process. The following
process by M. Claudet was carried out to some extent with every prospect of success.
The new art, patented by M. A. F. J. Claudet on the 21st November, 1843, was
established on the following facts. A mixed acid, consisting of water, nitric acid*
nitrate of potash, and common salt in certain proportions, being poured upon a Da-
guerreotype pictare, attacks the pure silver, forming a chloride of that metal, but does
not affect the white parts, which are produced by the mercury of the picture. This
action does not last long. Water of ammonia, containing a little chloride of silver
in solution, dissolves the rest of that chloride, which is then washed away, leaving
the naked metal to be again attacked, especially with the aid of heat The metallic
surface should have been perfectly purified by means of alcohol and caustic potass.
For the rest of the ingenious but complex details, see Newton's Journal^ C. S. vol. xxy.
p. 112. — Sec Actinism, Collodion, Photography.
DAHLINE, the same as Inuline. The fecula obtained firom elecampane, ana-
logons in many respects to starch. It has not been employed in the arts.
IdAMAR gum, or DAMMARA RESIN. A pale yellow resin, somewhat resem-
bling cupal, and used like it in the manufacture of varnishes. Dammara resin is
said to be derived from the Pinus dammara alba of India. A Dammara resin is also
imported fi*om New Zealand, which is the product of the Dammara Australu. Under
the name of Cowdie resin it is said to be used extensively as a varnish in America.
** Damar is easily dissolved in oil of turpentine, and when careAilly selected is almost
colourless ; it makes a softer varnish than mastic ; the two combined, however, form
an almost colourless varnish, moderately hard and flexible, and well suited for maps
and similar purposes." — Holtzapffd, ^
DAMASCUS BLADES, are swords or scymitars, presenting upon their surface a
variegated appearance of watering^ as white, silvery, or black veins, in fine lines, or
fillets ; fibroQS, crossed, interlaced, or parallel, &c. They are brought fh)m the East,
being fabricated chiefly at Damascus, whence their name. Their excellent quality-
has become proverbial ; for which reason these blades are much sought after by mi-
litary men, and are high priced. The oriental processes have never been satisfactorily
described ; but of late years methods have been devised in Europe to imitate the fabric
very well.
DAMASCUS BLADES. 5
Clonet and Hachette pointed oat the three following processes for producing Da-
mascus blades : 1, that of paraUel JUleta; 2, that by torMion; 3, the motaic. The
£ret, which is stiil pursued by some French cutlers, consists in scooping out with a
graving tool the finoes of a piece of stuff composed of Uiin plates of different kinds of
steeL These hollows are by a subsequent operation filled up, and brought to a level
with the external fiuses, upon which they subsequently form tress* like figures. 2. The
method of torsion, which is more generally employed at present, consists in forming
a bundle of rods or slips of steel, which are welded together into a well- wrought bar,
twisted sereral times round its axis. It is repeatedly forged, and twisted alternately ;
after which it is slit in the line of its axis, and the two halves are welded with thdr
outsides in contact ; by which means their faces will exhibit rery various configura-
tions. S. The mosaic method consists in preparing a bar, as by the torsion plan, and
cutting this bar into short pieces of nearly equal length, with which a &ggot is formed
and welded together ; taking care to preserve the sections of each piece at the surfiice
<jf the blade. In this way, all the variety of the design is displayed, corresponding to
each finagmeut of the cut bar.
The blades of Clouet, independently of their excellent quality, their flexibility, and
extreme elasticity, have this advantage over the oriental blades, that they exhibit in
the Tery substance of the metal, designs, letters, inscriptions, and, generally spetJiing,
all kinds of figures which had been delineated beforehand.
Notwithstanding these successful results of Clouet, it was pretty clear that the
watered designs of the true Damascus scymitar were essentially different M. Bryant
has attempt^ a solution of this problem. He supposes that the substance of the
oriental blades is a cast steel more highly charged with carbon than our European
steel, and in which, by means of a cooling suitably conducted, a crystallisation takes
place of tsfb distinct combinations of carbon and iron. This separation is, he thinks,
the essential condition ; for if the melted steel be suddenly cooled in a^mall crucible
or ingot, there is no damascene appearance.
If an excess of carbon be mixed with iron, the whole of the metal will be converted
into steel ; and the residuary carbon will combine in anew proportion with a portion
of the steel so formed. There will be two distinct compounds ; namely, pure steel,
and carbnretted steel or cast'iron. These at first being imperfectly mixed, will tend
to separate if while still fluid they be left in a state of repose ; and form a crystalli-
sation in which the particles of the two compounds will place themselves in the cru-
etble in an order determined by their affinity and density conjoined. If a blade
forged out of steel so prepared be immersed in acidulous water, it will display a very
distinct Damascus appearance ; the portions of pure steel becoming black, and those of
carburetted steel remaining white, because the acids with difficulty disengage its carbon.
The slower such a compound is cooled* the larger the Damascus veins will be. Ta-
Temier relates that the steel crucible ingots, like those of wootz, for making the true
oriental Damascus, come from GolcondiE^ that they are the size of a halfpenny roll, and
. when cut in two, fbrm two swords.
Steel combined with manganese displays the Damascus appearance very strongly.
A mixture of 100 parts of soft iron, and 2 of lamp black, melts as readily as ordinary
SteeL Several of the best blades which M. Bryant presented to the Society d'Encour-
agement are the product of this combination. This is an easy way of making cast-
steel without previous cementation of the iron. 100 parts of filings of very grey cast-
iron, and 100 parts of like filings previously oxidised, produced, by their fusion to-
l^ether, a beautiful damascene steel, fit for forging into white arms, sabres, swords, &c.
This compound is remarkable for its elasticity, an essential quality, not possessed by
the old Indian steeL The greater the proportion of the oxidised cast-iron the
tougher is the steel. Care should be taken to stir the materials during their fusion,
before it is allowed to cr.ol ; otherwise they will not afford a homogeneous damasc.
If the steel contains much carbon it is difficult to forge, and cannot be drawn out ex-
cept within a narrow range of temperature. When heated to a red- white it crumbles
itnder the hammer; at a cherry-red it becomes hard and brittle; and as it progres-
sively cools it becomes still more unmalleable. It resembles completely Indian steel,
which European blacksmiths cannot forge, because they are ignorant of the suitable
temperature for working it M. Breant, by studying this point, succeeded in forging
fine blades.
Experience has proved that the orbicular veins, called by the workmen knots or
ikonu (r<mce$\ which are seen upon the finest Eastern scymitars, are the result of the
jnanner of forging them, as well as the method of twisting the Damascus bars. If
these be drawn in length, the veins will be longitudinal ; if they be spread equally in
all directions, the stuff will have a crystalline aspect ; if they be made wavy in the
two directions, undulated veins will be produced like those in the oriental Da-
b3
6 DAMASK
The cliaTacteristics ascribed to the real Damascus blades are extraordinary keenness
of edge, great flexibility of substance, a singular grain of fleckiness always observable
on tbe surface, and a peculiar musky odour given out by any friction of the blade»
either by bending or otherwise. The author of ** Manufactures in Metals,*' remarks:
^ A gentleman who purchased one of these blades in the East Indies for a thousand
piastres, remarked to the writer of this volume that, although the instrument was
very flexible, and bore a very keen edge, it could not with safety be bent to more
than 45^ from the straight shape, and it was not nearly so sharp as a razor, yet,
wielded by a skilful hand it would cut through a thick roll of saiUcloth without any-
apparent difficulty ; a feat which could not be performed with an ordinary sword, nor,
it should be observed, by the sabre itself in an ordinary hand, though the swordsman
who tried it could, it appears, do nearly the same thing with a good European
blade."
Emerson, in his letters from the ^gean, says : ^ I have seen some blades (scy-
mitars) which were valued at 200 or 300 dollars ; many are said to be worth triple that
sum, and all retain the name of Damascus^ though it is by no means likely that they
have been manufactured there. The twisting and interwisting of the fibres of the
metal are considered as the tests of excellence, but I have never seen any possessed
of the perfume said to be incorporated with the steel in the real Damascus blade."
The production and use of damask steel has received much attention from the
late General Anossoff, of the Corps of Engineers of the Imperial Russian army, and
Master of the Fabric of Arms at Zlataonst, in Siberia. His researches and suec^sful
practice have become matters of history.
Steel helmets and cuirasses were formed of cast and damascened steel, intermixed
with pure iron, a mixture supposed to combine toughness and hardness in greatest
possible degree.
At different periods these works have been visited, separately, by two English
travellers. Major Abbott of the Bengal Artillery, and Mr. Atkinson, who have
recorded the results of observation^ experiment, and conversational intercourse, and
they state severally their conviction that the damask steel produced by Anossoff
rivalled in beauty and excellence any works they had ever seen in other landa They
accord to Ano6so£P the honour of being the reviver of the art of making damask steel
in Europe, while they declare the Russian natural damask steel is not approached by
the fabrics of any Eastern nation now existing.
The Siberian swords and daggers were compared and tried with the choicest spe-
cimens, and found equal to the blades of Damascus, and the sabres of Khorassan;
and while these valued articles might have been selected from numbers manufactured
by chances of skill and material, Anossoff united chemical analyses of ores and steel,
and records of observations on progressive stages, to give a true history of the means
to explain and insure success. See Sword MANUFAcruaiL
DAMASCUS GUN-BARRELS. See Gon-babrsl.
DAMASK is a variegated textile fabric, richly ornamented with figures of flowera^
fruits, landscapes, animals, &C., woven in the loom, and is by far the most rich, elegant,
and expensive species of ornamental weaving, tapestry alone excepted. The name is
said to be derived from Damascus, where it was anciently made.
Damask belongs to that species of texture which is distinguished by practical men
Jby the name of tweeling, of which it is the richest pattern. The tweel of damask is
usually half that of full satin, and consequently consists of eight leaves moved either
in regular succession or by regular intervals, ei^ht leaves being the smallest number
which will admit of alternate tweeling at equal mtervals.
The generic difference of tweeling, when compared with common cloth, consists in
the intersections, although uniform and equidistant, being at determinate intervals, and
not between the alternate threads. Hence we have specimens of tweeled cloth, where
the intersections take place at the third, fourth, fifth, sixth, seventh, eighth, or six-
teenth interval only. The threads thus deflecting only from a straight line at inter-
vals, preserve more of their original direction, and a much greater quantity of ma*
terials can be combined in an equal space, than in the alternate intersection, where
tbe tortuous deflection, at every interval, keeps them more asunder. On this principle
tweeled cloths of three and four leaves are woven for facility of combination alone.
The coarser species of ornamented cloths, known by the names of domock and diaper,
usually intersect at the fifth, or half satin interval. The sixth and seventh are rarely
used, and the intersection at the eighth is distinguished by the name of satin in
common, and of damask in ornamental tweeling. It will further be very obvious^
that where the warp and woof cross only at every eighth interval, the two sides of the
cloth will present a diversity of appearance ; for on one side the longitudinal or warp
threads will run parallel from one end of a web to the other, and, on the other, the
threads of woof will run also parallel, but in a transverse direction across the doth.
DATURINE. 7
or at rigbt angles to the former. The points of intersection being onlj at erery
eighth interval, appear only like points ; and in regular tweeling these form the ap-
pearance of diagonal lines, inclined at an angle of 45^ (or nearly so) to each of the
former.
The appearance, therefore, of a piece of common tweeled cloth is very similar to that
of two thin boards glued together, with the grain of the upper piece at right angles
to that of the under one. That of an ornamental piece of damask may, in the same
manner, be rery properly assimilated to a piece of veneering, where all the wood is of
the same substance and colour, and where the figures assume a diversity of appearance
from the ground, merely by the grain of the one being disposed perpendicularly to that
of the other.
From this statement of the principle, it results that the most unlimited variety of
figures will be produced, by constructing a loom by which every individual thread of
warp may be placed either above or below the woof at every intersection ; and to effect
this, in boundless variety, is the olject of the Jaequard mounting. See Loon, Jao-
The chief seat of this manufacture is the town and neighbourhood of Dunferm-
line, in Fifeshire, — and Lisbum and Ardoyne, near Belfast, where it is considered
as the staple, having proved a very profitable branch of tridfic to the manufacturer,
and giren employment to many industrious people.
The material used there is chiefly linen ; but many haye been recently woven of
cotton, since the introduction of that article into the manufacture of cloth has become
so prevalenL The cotton damasks are considerably cheaper than those of linen, but
are not considered either so elegant or durable. The cotton, also, unless frequently
bleached, does not preserve the purity of the white colour nearly so well as the linen.
DAMASKEENING.; the art of ornamenting iron, steel, &c., by making incisions
npon its surftce, and filling them up with gold or silver wire ; it is chiefly used in en-
chasing sword blades, gnsjrds, and gripes, locks of pistols, &c
Its name shows the place oif its origin, or, at least, the place where it has been prac-
tised in the greatest perfection, vis. Uie city of Damascus, in Syria ; though M. Fell*
bien attributes the perfection of the art to his countryman, Cursinet, who wrought
under the reign of Henry IV.
Damaskeening is partly mosaic work, partly engraving, and partly carving. As
mosaic work, it consists of pieces inlaid ; as engravmg, the metal is indented, or cut
in intaglio; and as carving, gold and silver are wrought into it in relievo.
There are two ways of damaskeening ; in the first, which is the most beautiful, the
artists cut into the metal with a graver, and other tools proper for engraving upon
ateel, and afterwards fill up the iocisions, or notches, with a pretty thick silver or
gold wire. In the other, which is only superficial, tbey content themselves to make
hatches, or strokes across the iron, &c., with a cutting knife, such as is used in making
small files. Atf to the first, it is necessary for the gravings or incisions to be made in
dove-tail form, that the gold or silver wire, which is thrust forcibly into them, may
Adhere the m<M« strongly. As to the second, which is the more usual, the method is
this : having heated the steel till it changes to a violet, or blue colour, they hatch it
over and across with a knife, then draw &e ensign or ornament intended upon this
liafAhing with a fine brass point or bodkin. This done, they take fine gold wire, and
eoodncting or chasing it according to the figures already designed, they sink it care-
fully into the hatches of the metal with a copper tooL
An inferior description of damaskeen work has been introduced since the discovery
Off the electrotype processes. The pattern has been etched on the steel, and then
gold or silver deposited into the etched lines.
DAHASSIN. A kind of damask, with gold and silver flowers woven in the warp
and woot, or occasionally with silk organsine.
DAMP, til mining are dangerous exhalations, or rather gases, — so called from the
German dampf, vapour ^escaping from the mineral formations, or accumulating in
the workings.
Ftre-Vanq), which occurs in coal mines, is carburetied hydrogen gae*
Ckoke-Dangf}, After- Damp^ and Black Damp, may be regarded as Carbonic acid.
See M1NE8, ventilation of ,
DAPHNINE. The bitter principle of the Daphne alpina.
DASH WHEELS. These were revolving wheels having dash-boards, which are
inoeh used in the washing processes necessary in calico printing. See Bi^achino.
DATHOLITE. Borusilicate of lime, called also Esmarkite and Uumboldiite. It
18 found at Arendal in Norway and in New Jersey.
Its chemical composition is, silica 37 '30 ; boracic acid 21*32 ; lime 35*67 s water 571.
DATURINE. See Atropine.
DEAL WOOD. See Pimbs.
B 4
8 DECOMPOSITION.
DECANTATION. (Eng. and Fr.$ Abguasen, Germ.) The act of poqrinif
off the clear liquor from any sedimexit or deposit. It is mnch employed in theehemi-
cal arts, and it is frequently effected by means of a siphon, there being less Hak of
disturbing the precipitate.
DECKLE, name giren by the paper maker to a thin frame of wood fitting on tlie
shallow mould in which the paper pulp is placed.
DECOCTION. (Eng. and Fr. ; Zeraetzung, Germ.) The process of boiling a liquid
with some organic body, or the liquid compound resulting from the process of boiling.
DECOMPOSITION. The separation of bodies from each other. The methods
employed are almost inntimerable, and usually depend on the special reactions of the
matters under examination. We shall consider a few of the most striking cases in
both the grand divisions of the science, riz. inorganic and organic chemistry. In
each instance we shall, for the sake of convenience, subdivide into the three classes of
acids, alkalies, and neutral bodies. Prerions, however, to this, we must glance at
some of the reactions of which chemists avail themselves in separating the elementa.
The decomposition of ordinary metallic salts, with the view of making a qualitative
analysis of a more or less complex mixture, is a problem, in general, of extreme
simplicity, and directions for the purpose are to be found in all the numerous works
on qualitative analysis. The principle on which the modem methods of qualitative
analysis are founded, is the separation of the metals in the first place into large groups
by certain reagents, and then by means of others, to subdivide into smaller groups, in
which the individual metals can be determined by special (esti. For the sake of
simplicity, we shall only consider the more commonly occurring metals. The general
reagents, by which the first subdivision is effected, are hydrochloric acid, sulphuretted
hydrogen, sulphide of ammonium, carbonate of ammonia mixed with chloride of
ammonium, and finally phosphate of soda. The substance in solution is treated with
hydrochloric acid, by which mercury, silver, and lead are removed. The mercury
will only be perfectly removed if it exists entirely in the state of a subsalt. Lead is
only partially precipitated, and will be subsequently found in the next group. The
precipitate by hydrochloric acid is to be boiled with water, which will remove the
chloride of lead, and leave the chlorides of mercury and silver. The hitter may be
separated by means of ammonia, which will dissolve the chloride of silver and
convert the mercury into a black powder, in which the metal can be detected by
special tests. The fluid filtered from the precipitate by hydrochloric acid, is to have
a stream of hydrosulphuric acid gas passed through it for a considerable time, or
until no more precipitation occurs. By this means antimony, arsenic, tin, cadmium,
gold, mercury, silver, lead, bismuth, and copper are thrown down, and must be
separated from each other by special processes. The filtrate from the precipitate by
hydrosulphuric acid is to have ammonia added in slight excess, and then a solution of
sulphide of ammonium as long aa any precipitation takes place. By this means
nickel, cobalt, iron,''manganese, zinc, alumina and chromium, are thrown down ; also
baryta, strontia, and lime, if they happen to be in combination with pho^horic oxalic
or boracic acids, or if united to fluorine. From the flltrate, carbonate of ammonia
mixed with chloride of ammonium, precipitates baryta, strontia, and lime. The filtrate
from the last precipitate can only contain magnesia, or the alkalies. The above brief
description of the mode of dividing the metals into groups will be sufficient to give an
idea of the processes employed for decomposing complex mixtures into simple. ones.
Inorganic acids are usually removed from metals by converting the latter into an
insoluble compound, while the acid remains in solution either m the free state or
combined with a body of such a nature as not to mask the reactions of the acid with
reagents. This is often done in the laboratory by boiling the metallic salt with an
alkaline carbonate. The metals are, consequently, either converted into oxides or
carbonates insoluble in water, while the acid unites with the alkali to form a soluble
salt capable of being obtained by filtration in such a condition ns to permit the nature
of the acid to be made known by means of appropriate tests. It is usually necessary
to neutralise the solution carefully before testing for the acid.
It is seldom necessary in researches to reduce inorganic alkalies to their elements,
their constitution being usually ascertained by converting their constituents into
new forms capable of being weighed or measured with accuracy. If, for instance^
it was necessary to ascertain the constitution of sulphuric acid, it would be sufficieot
10 determine the quantity of baryta contained in the sulphate. On the other hand,
acids susceptible of assuming, when pure, the gaseous condition may have their con-
stitution determined by decomposing a known volume with a substance capable
of combining with one ingredient and liberating the other in the gaseous states
Thus hydrosulphuric acid may be analysed by heating it with potassium, which will
remove the sulphur and liberate the hydrogen.
In decomposing inorganic alkalies with the view of separating the metals contained
DECOMPOSITION. 9
in them, we osoally liave to aTail oonelves of rerj poverfnl affinities. This arises
lirom the fact, that the substances in question are, generally, produced by the nnion
of a metal with oxygen, the metal having so strong a tendency to combine with that
element, that mere exposure to the air is sufficient to determine their union into a
compound of great stability. In order, therefore, to decompose the alkalies of this
class, it is necessary to find some substance having a powerful tendency to combine
with oxygen under certain conditions. Mow it has been found that carbon, if raised
to an exceedingly high temperature, and employed in great excess, is capable of
remoTing the oxygen, even ftom such bodies as potassium and sodium, tbe affinity
of which for oxygen is very great.
Inorganic neutral bodies are generally decomposed either by the ordinary pro-
cesses of analysis, or, where the neutrality arises ttom the substance under examina-
tion being a compound of an acid and a base, by separating the two by treatment
with a reagent capable of combining with one to the exclusion of the other. This is
a process frequently available in quantitative analysis. As an illustration, we mar
take the decomposition of the carbonates by a mineral acid in an apparatus whicn
permits the carbonic acid set free to be accurately estimated by weighing. (See
Cabbonates.) Another instance of the decomposition of a neutral body, by treating
it with a substance capable of combining with one of the constituents and separating
the other in a free state, is the decomposition of sulphate of potash by baryta. If a
solution of the salt be boiled with excess of solution of baryta, sulphate of baryta is
produced and caustic potash set free. The excess of baryta is removed by boiling in
the air until the whole of the latter base is converted into the insoluble carbonate.
A precisely analogous process is the ordinary mode of preparing caustic potash by
boiling its carbonate with quicklime.
Neutral bodies are frequently, howerer, so constituted, that the neutrality does not
arise from the circumstance of an acid being saturated with a bsse, but from the
energies of two elements being, to some extent, satisfied by the fiict of their being in
combination. Thus, water is a neutral substance, nevertheless it may be decomposed
by a variety of processes, several of which are susceptible of quantitative precision.
In the first place, it may be decomposed by passing steam over a metal capable of
uniting with its oxygen with liberation of the hydrogen. It may also be electrolysed
and the two gases separately obtained.
Organic or inorganic neutral salts may, at times, be very completely and simply
decomposed by means of the battery. Not only are the various processes in electro-
metallurgy founded on this principle, but it has even been practically applied to the
qoantitative estimation of the metals in ores. The electrolysis of the neutral salt of
the great series of organic acids of the general formula C^H^O' has thrown great
light on some previously obscure points in the radical theory.
The decompositions undergone by organic substances in contact with reagents are
so manifold, that the limits of this work preclude the possibility of doing more than
glancing at a few of the most general and interesting. Perhaps of all the modes of
inducing the breaking up of more complex into simpler substances, the application of
heat is the most remarkable for its power and the varied and opposite character of
the substances produced. It has been shown that, as a decomposing agent, heat
possesses no special function. From complex organic molecules all classes of sub-
stances are formed. Individual substances belonging to every chemical type are,
therefore, found among products of destructive distillation. Acids, alkalies, and
neutral bodies of every kind are formed, and some of the most interesting and beauti-
ful bodies known to chemists are found in the uninviting looking tar of coal. Let
us illustrate this by a glance at a few of the coal-tar products. Among the acids are
the oxyphenic, carbolic, and cresylic. The alkaloids represented are methylamine,
ethylamine, propylamine, butylamine, amylamine, pyridine, picoline, lutidine, coUi-
dine, parvoline, chinoline, lepidine, cryptidine and aniline. Among hydrocarbons,
benzole, toluole, xylole, dumole, cymole, propyle, butyle, amyle, caproyle, caproylene
cenanthylene, naphthaline, anthracene, chrysene, pyrene, &c. &c. This list, probably,
does not include one half of the substances produced from coal by the decomposing
and recomposing influence of heat
Mineral acids exercise a powerful decomposing influence on organic substances. Of
these the nitric and sulphuric are the most commonly used. Nitric acid is especially
active, owing to its twofold action. By virtue of its oxidising tendencies, it breaks up
great numbers of substances into more simple and less carburetted derivatives, and the
byponitric acid produced by the removal of one of the atoms of the oxygen^ of the
acid frequently enters into the resulting compound, a substitution product being the
final result. In the latter bodies produced in this manner the byponitric acid (NO*)
generally replaces hydrogen, the original type remaining unaltered. The production of
oxalic acid from sugar ; succinic, lipic, adipic, pimelic, suberic, &C., acids firom oily
10 DEPHLOGISHCATED.
and &ttj ttiatters hy the action of nitric acid, are examples of its oxidising power i
while the formation of nitrobensole, and bodies of more or less analogous character,
present instances of the replacement of hydrogen by hyponitric acid.
Sulphuric acid owes its decomposing power to its extreme tendency to combine
with water. Many of the less stable organic bodies are, by this means, absolutely
broken up, so that the resulting products are of a character too indefinite to allow of
the changes being expressed by an equation which shall jender a true account of all
the substances directly or indirectly formed. On the other hand, the action may be
so controlled by the careful regulation of the temperature and strength of the acid
that products may be eliminated which are themselves totally broken up and destroyed
by an acid of greater strength. The production of g^pe sugar by the action of sul-
phuric acid on starch, or lignine, may be taken as an example. It not unfrequently
happens, that the sulphuric acid unites with the substance acted on to form a conju-
gated compound. Benzole, and many other hydrocarbons, as well as oxidised bodies,
behare in this manner with concentrated sulphuric acid.
Chlorine and the other halogens are powerful decomposing agents, acting chiefly
by virtue of their affinity for hydrogen. The principal effects produced by them are
oxidation and substitution. The oxidising action of the halogens arises from the
decomposition of water ; the hydrogen combining with the chlorine, &C., to form an
bydracid, and the free oxygen uniting with the other substances present
The above sketch will sufficiently indicate some of the most usual methods by
which the decomposition of organic and inorganic bodies is effected ; but hundreds
of other decomposing agencies are at the call of the chemist, when any phenomena
involving the disruptions of compounds are to be investigated. — C. 6. W.
DECREPITATION (Eng. and Fr ; Verknistem, Germ.) is the crackling noise,
attended with the flying asunder of their parts, made by several minerals and salts
when heated. Sulphate of baryta, chloride of sodium, calcareous spar, nitrate of
baryta, and several other bodies which contain no water, decrepitate most violently,
separating at the natural joints of their crystalline structure.
DEFECATION. (Eng. and Fr. ; Klaren, Germ.) The freeing from dregs or
impuritiea
DEFLAGRATION. (Eng. and Fr.; Verpuffung, Germ.) A rapid combustion,
attended with much evolution of flame and vapour. When metals are burnt by elec-
tricity, they are said to undergo deflagration.
DEFLAGRATOR. A galvanic instrument for producing a rapid and powerful
combustion, introduced by Professor Hare.
DE LAINES. Properly, fine worsted fabrics. They are indeed figured muslins,
which should always be made of wool, but they are frequently made of mixed materiaL
DELF. A coarse species of pottery originally manufactured at Delft in Holland,
covered with a white enamel or glase. See Pottery.
DELIQUESCENT. (Zer/liessen, Germ.) Any solid which absorbs moisture from
the air spontaneously, and becomes soft or liquid; such as potash, and chloride of
calcium.
DELPHINI A. The poisonous principle of the Stavesacre.
DEMY. Paper of a particular size is so called. Drawing demy is 15 inches by 20 ;
printing demy is 17} inches by 22^.
DENUDATION. {Denudo, to ky bare.) The carrying away by the action of run-
ning water of the superficial solid materials of the land, by which the lower rocks are
laid bare.
DEODORISERS. Bodies which have the power of depriving fetid and offensive
effluvia of their odours. There appears to exist a general idea that these substances
are, all of them, equally disinfectants. No greater mistake can be made than to suppose
that because a preparation has the power of removing a disagreeable smell, that there-
fore it has removed all the elements of infection or disease. See Disinfectant.
To disguise unpleasant odours, fumigation is employed, many of the fhtgrant gums
are burnt, and fumigating pastiles employed* It is also a common practice to bum
lavender and brown paper, but these merely overpower or disguise the smell ; they do
not in any way act upon the noxious effluvia. See Pastiles. Fumigation.
DEPHLEGMATION. The process by which liquids are deprived of their
watery particles. It is applied chiefly to spirituous liquors, but is now obsolete, as
involving the alchemistical notion of a peculiar principle called phlegm.
DEPHLOGISTICATED, deprived of phloffiston, which was for a long period
after the time of Stiihl regarded as the principle of levity and of combustion. It may
be regarded as synonomous with oxygenated. ** Others believe that Earih and Phlo^
gition are those principles which are the constituent parts of all corporeal substances.**
" It appears from all those experiments, that in each of them phtogUUm^ the simple
inflammable principle, is present" '* Thus much I see from the above mentioned
DESICCATION.
11
experiments ; that air is composed of two different fluids, the one of which attracts
not the phlogUiotL, and the other has the quality of attracting it.** ~^ SehetU : Experi-
wtenJtM <m Air and Fire.
DEFILATORl£& Preparations for removing hair from the shin. These are
aaid to hare hcen mnch used bj the ancients. In modem times they have been used
as cosmetics to remove superflnous hair from the face. Lime and the tersulphoret of
arsenic (Qrpiment) are the constitnents of most of the ancient and modern depilatories;
but the use of orpiment is dangeroos, especially if there is any abrasion of the skin.
The best and safest depilatory is said, in Uray's Supplement to the Pharmaeopttia^
edited bf Redwood, to be a strong solution of sulphuret (sulphide) of barium made into
a paste with powdered starch. It should be applied to the hair immediately after it
is mixed, and allowed to remain there for five or ten minutes.
DEPOSITION OF METALS. See ELBcrao-MBTAixuaoT.
DERBYSHIRE SPAR. Fluor spar, or fluoride of calcium ; which see.
DERRICK CRANEL The term Derrick is applied to a temporary crane, con«
sisting of a spar supported by stays and guys, carrying a purchase fbr loading or un«
loading goods on shipboard. The Derrick crane is somewhat similar in its plan, the
projecting iron beam, or derrick, of which can be raised or lowered to any desired
angle.
DESICCATION. The act of drybg.
Davison and Symiagton patented a process for dryinjif or seasoning timber, by
carrents of heated air. Even after wood has been dried m the ordinary manner, it
eontains much moisture, which it is still necessary to remove. The patentees have
given some carious results of this desiccating process: —
Temperature of air 214^.
▼ioUnwood.
Original
weight.
Wright aftor
■OMODlng.
Moioture removed.
6 pieces small and thin
2 pieces larger - - - -
2 pieces larger - - - -
3*38
10*56
25*25
2*87
9*5
22-93
8* per cent
10*1 do.
9-25 do.
Original
. 1 - •- ^
lOQO
ISOO
IfiOO
180»
2300
after
after
after
after
after
Percent.
Oak - - - -
veigbt.
6 hour*.
lOhouri.
90 hours.
30 hour*.
38 hour*.
1*84
1-76
1-71
1*59
1*56
1*51
18*1
Red pine - - -
1*5
1*4
1*38
1*33
1*28
1*25
16-6
Birch
1*2
1*09
1*05
1*01
•99
•97
19-2
Mahogany
1*21
M4
1*09
103
1*0
•98
19-2
White woody lime tree.
1
2
3
4
Origioal
we^t.
170P
after6hourt.
Part 1400, and
part SI 80
after 15 houn.
After
94 houn.
After
84 hours.
After
84 hours.*
Per cent.
*/3*5
25*19
23-67
20-08
20-45
21*33
19-7
17*07
18*7
19*37
17*83
15*8
18*22
18*9
17-6
15*6
17*4
18*07
16*82
15*13
17*4
18*0
16-75
15*05
26*
28-5
29-2
25*
Ka 8 exposed to the atmosphere for three weeks, weighed at the end of that time
17-8, or had taken in 4*2 per cent, of moisture.
jPcaifter«.^Feather beds, mattresses, blankets, and clothing, are not only dried, but
purified by this process. A feather bed of sixty pounds weight, will have no less than
100,000 cubic feet of mt passed through it; and at the same time beaters are made use
of, for the purpose of removing the dust Feathers treated in this manner have their
• It will be obterted, on referring to the last column of lime, that the wood,
chamber exposed to heated currents for 50 hours, weighed nothing less after
( ir*atew). One application of the deslcoiting process for timber |s Io expoM It
heated carrenU of air, and then, in Its heated sUte, Immersmg it suddenly In
BBUscpdcs, creosote or coal-ur. The result U. that the alr-Tessels of the wood,
conUfn ah- at so Terr high a temperature that a ?acuum Is InstanUy formed, and
dbtely cbarged with the cold antiacpilc la which the wood Is fannMrsed.
although kept in the
the first 34 hours*.
for some hour^ to the
enjrof the i^iprOTed
If not entirely empty,
e?erj pore Is imne-
12 DESICCATION.
balk and elasticity so much increased, that a second tick is found almost inTariably
necessary to put the feathers into.
A practical proof of the extreme powers of currents of dry heated air was giren in
Syria, by exposing to them sixty suits of clothes, which had belonged to persons who
died of the plague. These clothes were subjected to the process alluded to, at a tem-
perature of about 240% and afterwards worn by sixty living persons, not one of whom.
e'ver gave the slightest symptom of being in the slightest degree affected by the malady*
{Whiskaw.) The purification of feathers by this process is carried out in many
large establishments. Coffee it has been proposed to dry by currents of heated air,
and subsequently to roast it by the same process.
Thick card-board^ used for tea-trays and papier mache, is now frequently dried by-
heated air. By the plan adopted at one establishment, previously to the introduction
of Davison and Symington's method, it invariably occupied from eighteen to twenty
hours to dry a room full of paper by a heating surface equal to 330 feet ; whereas by
the new method, the same amount of work is accomplished in four hours, and with a
heating surface of only 46 feet, or one seventh the area required by the fonner.
SUk. — For the purpose of drying silk, it has been usual to heat the drying chambers
by large cast-iron globular stoves, the heat obtained thus was equal to 120^ F., but
excessively distressing to any stranger entering these apartments.
In one arrangement 7000 cubic feet per minute are admitted at the above temper-
iiture through small perforated iron plates, let into the stone floor. As many as 3000
pieces of silk are sometimes suspended at one time ; and as each piece of silk, when
wet contains about seven ounces of water, and as the operation of drying the whole
occupies but one hour, it follows that about ISO gallons of water are evaporated in
that time.
Yarfu, — In Scotland and other places they now dry yams by modified applications
of this process; and it is indeed extensively used in bleaching establishments, in
calico-printing works, &c See Transactions of the Society of Arts for 1847-^.
A DRYING HOUSE IS an apartment fitted up in a peculiar manner for drying calicoes,
and other textile iabrics. Mr. South worth, of Sharpies, a Lancashire bleacher, obtained
a patent in 1823, for the following ingenious arrangement, which has been since gene-
rally adopted, with certain modifications, in most of our extensive bleaching and
printing works. Fig, 641, is a section of the drying-house, where a is a furnace and
boiler for the purpose of generating steam; it is furnished with a safety valve in the
tube b, at top, and from this tube the steam main c passes down to the floor of the
basement story. From this main, a series of steam-pipes, as </ (f, extends over the surface
of the floor, and from them heat is intended to be diffused for the purpose of warming
the drying-house.
Along the middle of the building a strong beam of timber e e extends, and is
supported by cast-iron pillars ; from this beam, to bearings on the side walls, a series
of rails are carried in a cross direction, over which rails the wet cloth is to be hung iu
fulds, and the steam or evaporation emitted in drying is allowed to escape through
apertures or ventilators in the roof.
The mode in which the cloth is delivered on to the rails, on either side of the beam
will be best understood by reference to the delivering carriage, which is shown, with
its rollers partly in section.
The wet cloth is first to be coiled upon a roller, and then placed in the carriage, as
aty) with its pivots bearing upon inclined planes. The carriage is to placed at the
commencement of the rails, running upon the middle beam, and also upon the side-
bearings or railways extending along the side walls of the building, parallel to and
upon a level with the same beam. It is made to travel by means of an endless band
passing over two riggers g and A, in fig^ 604, and over pulleys and a band- wheel
attached to the carriage, as will be explained. The rigger ^, which moves this endless
band, is actuated by bevel gear, seen at 5, which is put in motion by a pinion at the end
of a revolving shaft leading from a steam engine.
in the same^^., k h, is ^e endless band passing over a pulley under tbe band-wheel,
and over the pulley n, by which it will be perceived that the traversing of the band, as
described, would cause these pulleys and wheels to revolve. On the action of the band-
wheel ffi, there is a drum against which the roll of wet cloth /presses, and as this drum
revolves, the roll of wet cloth is, by its friction, made to turn in a contrary direction,
and to deliver off the cloth on to the periphery of the drum, whence it passes over a
roller and descends to the rails. Upon the end of the axle of the band wheel m, there
is a pinion which takes into the teeth of the large wheel, and upon the axle of this
large wheel there is a pinion that actuates the intermediate wheel which turns another
toothed wheel. This last mentioned toothed wheel takes into cogs upon the side rail-
way, and hence, as the train of wheels moves round, the carriage to which the wheels
are attached is slowly impelled forward.
DESICCATION.
1»
Ai MOD u tfae wfaeeti ^gin to more, sod tbe oirUgt to idTance, the we( clo(k
ttegint to ODiMil, and to pan down orer the flnt roller ; ■ imall roller attached to the
carriage, ai it puKS orer the rail in SDCceiaioa, bolda the cloth againit each rail for a
abort apace of time, and pre* enti it fR>m alippitig, by which meam the clotb deMenilt
in foldi or loopa between the rail*, and i> thereby made to baog in a wrie* of Told* or
loops u sfaowD in Ibe figure.
It will be perceived (hat a* the piTOtl of tbe cloth roller/ bear upon inclined planei,
the roller will coDtinnallj elide down a* tbe cloth dimiiii«het in bolh, keeping in con-
tact with the dram, and delivering the cloth from the roller od to the MTeral nil*, m
deccribed.
In order to atop the carriage in any part of it* coane, or to adjnitanjofthelbldiof
the cloth, ■ man la naoally placed npon the platlbrm travelling with the carriage, over
vhich he hai perftet command. Thii uparatni may be alio employed for taking tha
clotb when dried off ihe railii in which cafethecarriagemuitbemade lo travel back-
wards, and by fint goiding the end of Ibe cloth on to the roller/; and then pntling the
wheels in a retrograde motion, the cloth will be progreMivel; coiled opon tbe roller/,
in s aimilar way to that by which it was oncoiled.
I>BViHO MxcTHiira (cEHTRiruo*!,). (HfdTO-exlraeleur ,■ Mnehim i tuonr, Fr.)
By this coatrivance, PentsoldC wa* enabled to deprive all kinda of wet dotbes in a few
minntei of their moiitnre, wilbont compreiiion or heat Kelly, ft dyer, and Aliiolt
■ bleacher, have since obtained a patent far the above maobine with improvementi.
Fig, 64S, represent* \ pariial section of the mMhinc. a, a, U the frnmei b, Um
14 DESICCATION.
yerdcal shaft tarning in the step a, fixed on the bridge h. This shaft bears on its
upper part a friction cone c, from which it receives its movement of rotation, as will
be presently shown ; c is a dmm containing two concentric compartments d e, of the
form represented in the figure ;* this drum moves ft-eely upon the shaft b, and rests
when it is not in motion upon two conical projections /, g<, which form a part of the
shaft. These two compartments are each composed mainly of metal, and their
sides consist of tinned iron wire coiled circularly at very small distances from each
other, and soldered together crosswise by small strips of metal. The top which
covers the inner compartment d, is secured by bolts and screws to a circle of iron
which retains the wire sides of ihe same metal, hot that which serves as a cover to
the little compartment s, in which alone the goods are placed, is disposed so that it
may be removed with ease, when these are to be introduced or withdrawn. It is
furnished with an outer and inner border, disposed so that when the top is fixed the
inner border presses upon the convex circumference of the central compartment, while
the exterior border falls outside of the edges of the other compartment While the
machine is at work, the second plate is maintained in its place by pins or bolts, not
shown in the figure.
The sides of the outer compartment d^ are connected with the bottom by means of a
prolongation of cross bands of metal which unite the wires and are rireted or soldered
to the two outer plates. The wires of the interior compartment are attached by an iron
hoop, to which they are riveted and soldered, and are united to the bottom plate by
means of a rim upon this plate; a rim somewhat flattened upon the sides which are
riveted and soldered.
D, is a regulator suspended in the inner compartment d, and whose two branches A, A,
are loaded. These two branches having room to play around the bolts which serve as
points of attachment, and which are fixed to the upper plate, terminate in kneed
branches whose extremities rest upon a rope g, which projects ftom the shaft, e, is
an exterior envelope scoured to the frame a, a. It encloses the whole drum except
at top, and serves to catch the water thrown out of the gooda At y there is a stop
cock for the discharge of this water, and the bottom contains besides the end of a pipe
by which hot air is introduced.
The vertical shaft b receives a movement of rotation and carries with it the dmm.
The more rapid this movement is the more does the centrifUgal force tend to expel
the water contained in the clothes or yam to be dried. But as this force might also
displace the central shaft, if the weight was not rightly distributed in the drum, and
cause the dislocation of the machine when the great velocitv requisite for quick
drying is given to it, the regulator d is tested to prevent accident. The branches
of this regulator spread wider the more the velocity is increased, and raise conse-
quently the drum c above the conical enlargements, which permits the drum to be
somewhat misplaced and to rectify its position conformably to the inequalities of its
load, so that its centre of gravity may always coincide with its centre of rotation. The
drum is connected with the shidft as is shown in z, leaving it tree to take the requisite
acUustment. To hinder it ftom rising too suddenly, a spiral spring A is fixed over the
shaft immediately above the conical enlargement g. In order to maintain the equi-
librium more certainly, the apparatus is surrounded with a hollow crown f, half filled
with water, and if during the revolution of the machine the weight of the goods pre-
dominates on one side, that of the water which accnmulates on the other side serves the
more to counterbalance it The effect of this crown may be increased by dividing it
into two compartments or more, o, is a larse pipe by which steam or hot air is intro-
duced into the belly of the dmm, which is pierced in this place with a great number of
small holes to receive it
The rotary movement is transmitted to the dmm in the following way.
I, is a conical disc mounted upon the extremity of a shaft k' which actuates the cone c
and the shaft b by means of ft-iction ; l* is a cone fixed upon the extremity of the shaft.
k' l' ** is another cone of the same dimension, but whose base fronts the top of the other,
and which is placed on the shaft k* " commanded by the prime mover. H is the belt
which embraces the two cones, and whose lateral displacement, effected hj means of a
fork, permits the velocity of the machine to be regulated at pleasure, n is the pulley
which directly receives the movement In place of a single friction disc i, another
may be employed, if judged necessary, and placed between the two, an additional
friction pole, in order better to equalise the friction. In this case the disc and addi-
tional cone should turn freely upon their own shafts. We may also adopt another
arrangement for the bottom of the vertical shaft The shaft immediately above the
step is surrounded by a loose rim, around which a certain quantity of lead shot, or
other granular matter, is contained in the rim in the box which serves for the step.
The top of this box is pierced with an opening, into which, when the machine
is at rest, a cord connected with the shaft sinks, controlled by the shaft, and when
DIAMOND. 15
tlie drom is raised by the action of the TC|^1ator i^ this cord quits its place, vhich allows
the shaft to displace the shot a little, and to take a position confonnably to the point
of the centre of graf ity.
Bat after all great attention should be paid to the proper working of the machine.
There are many other drying machines used, some of which are described in the
articles deroted to special manufactures.
DETONATION. See Fulmiiiating, for the mode of preparing detonating powder
fiyr the percussion caps of fire-arms.
DETRITUS ; d^ from, tera, to rub. Matter worn off rocks, and deposited in
Talleys.
DEUTOXIDE, literally means the second oxide, but is nsaally employed to denote
n compound containing two atoms or two prime equiyalents of oxygen to one or more
of a mietaL Thus we say deutoxide of copper, and deuto^ide of mercury. Benelins
abbreriated this expression by adopting the principles of the French nomenclature
of 1787 ; according to which the higher stage of oxidisement is characterised by the
termination tc, and the lower by tmi. It is now rarely employed.
DEVIL. The name of a spiked mill, used in Yorkshire, for tearing wooUen rags into
fragments for the manofiicture of Shoddt.
DEVONSHIRE BATTS. A porous flne-grained sandstone from the quarries of
Black Down Clifb, near Collumpton, in repute as a grindstone.
DEVONSHIRE OIL-STONE. This stone occurs near Huel Friendship Mine^
about three miles from Tayistoek, in the Deyonian Slates of that district It has con-
siderable local repute for sharpening all kinds of thin-edged broad instruments ; it
has not, howeyer, become an article of conunerce. — Knight, Troaj. Society of Art*.
DEW-BETTING. See Flax.
DEXTRINE. Starch Gum. There are three modes of obtaining this from starch,
▼iz., by torrefaction, by the action of dilute acids, and by the action of diasUue. The
impure dextrine obtained by roasting is termed roaaUd ttarck, or kieomme. British
gum is prepared by carefully roasting wheat starch, at a temperature of 800^ Fahr.
Another method of preparing dextrine consists in moistening 1000 parts of potato
starch with 300 parts of water, to which 2 parts of nitric acid haye been added. The
mixture is allowed to dry spontaneously, and is afterwards heated for two or three
hours in a stoye, at S12 Fahr. Dextrine in many of its characters resembles or-
dinary gum, but it is distinguishable from it by its right'handed rotation of a ray of
pUmt polariaed light, — hence its name dextrine, — and by its yielding oxalic acid, but
not mucic acid, when heated with nitric acid. Its chemical formula is C^H'O'fHO.
DI ACTINIC LEN& A name proposed to be giyen to the best construction of
lens for the photographic camera obscora. It should be transparent to all the
chemical rays, or rather, a lens which should unite the chemical and luminous foci
in one point The name has not been generally adopted.
DIALLAGE. Bronzite, Ifyperstene, and SchUlertpar are ofti>n confounded nnder
this name. The name is deriyed from 9taXKctyn, difference, alluding to dissimilar
cleayage. It is thin, foliated, and easilpr deayable ; lamina brittle ; colour, yarious
shades of green, grey, and brown, sometimes bronxe and penriy metallic
Of diallage rode fine examples will be found near the Lizard Point, and beautiful
crystals of diallage are to be discoyered in the Serpentine rocks near Oadgwith, in
the same locality.
DIA MAGNETISM. As this term is becoming more generally used in our lan-
guage, it appcan necessary to giye a definition of it, although it is not our purpose
to enter on the consideration of any purely physical subject.
The term was introduced by Dr. Faraday, to express those bodies which did not
act as magnetic bodies do. If n and s represent the poles of a horse*8hoe magnet,
any bar of a magnetic character, as iron, cobalt or nickel, hong up between them^ and
free to moye, wUl by yirtue of the attracting and repelling polar forces, place itself
643 i^
y !; y
NO r ' -JOS
along the line joining the two poles a b, which is called the magnetic axis. If instead
of a bar of iron we suspend in the same manner a rod of glass, of bismuth, or of
silyer, it will arran^ itself equatorially, or across the line a 6, as shown by the dotted
line, c d. All bodies in nature appear to exist in one of those two conditions. The
prefix dia is ased here in the same sense as in dia-meter. See De La Bive's EUo
tricity, for a full explanation of all the diamagnetic phenomena.
DIAMOND (^Diamant^ Fr. ; Diamanf, Germ.) Experiment has determined that
16 DIAMOND.
this beantifol gem is a peculiar (aUotropic) condition of carbon. By burning the
diamond in oxygen gas we produce carbonic acid ; and by enclosing the gem in a
mass of iron, and subjecting it to a strong heat, the metal is converted into steel, when
the diamond has disappeared. It has been shown that we can, by the agency of the
heat of the voltaic arc, convert the diamond into excellent coke, and into graphite; bat
although portions of coke are found to be sufficiently hard to cut glass, we have not
yet succeeded in making diamonds fVom coke. Sir Humphry Davy noticed that the
charcoal of one of the poles of Mr. Children's great voltaic battery was considerably
hardened, and he regarded this as an advance towards the production of that gem.
Recently some experiments made by a French philosopher have advanced the dis-
covery another step : one of the poles of a voltaic battery being charcoal and the other
of platinum, it was found that the fine charcoal escaping from the carbon pole and
depositing itself on the plat^pum pole was sufficiently hard to be used in the place of
diamond dust for polishing gems. The formation of the diamond in nature is one ot
the problems which " our philosophy ** has not yet enabled us to solve. Time is an
element which enters largely into nature's works ; she occupies a thousand, or even
thousands of years to prcSluce a result, while man in his experiments is confined to
a few days, or a few years at most
Although diamonds have been occasionally found in various parts of the globe, there
are only two places which can be strictly named as diamond districts, a portion of the
Indian Peninsula and Braail. India has been celebrated from the most remote anti-
quity as the country of diamonds. Its principal mines are in the kingdoms of Goloondsi
and Visapour extending from Cape Comoriu to Bengal, at the foot of a chain of moun*
tains called the Ortro, which appear to belong to the trap rock formation. In all the
Indian diamond soils, these gems are so dispened that they are rarely found directly,
even in searching the richest spots, because they are enveloped in an earthy crust, whi^
must be removed before they can be seen. The stony matter is therefore broken into
pieces, and is then, as well as the looser earth, washed in basins scooped out for the
purpose. The gravel thus washed is collected, spread out on a smooth piece of ground,
and left to dry. The diamonds are now recognised by their sparkling in the sun, and
are picked out from the stone.
Diamonds are also said to come fVom the interior of the island of Borneo, on the banks
of the river Succadan, and Arom the peninsula of Malacca. It is said the principal spots
where diamonds are found are recognised by certain small flints, generally of a black
colour, which lie upon the surface, and also by the yellow colour of the stony soil The
ground is dug in the presence of an overseer : all stones above 5 carats, are claimed for
the sovereign. Diamonds are found occasionally in the rivers, seldom however of any
size.
The diamond mines of Brazil were discovered in 1728, in the district of Serro-do-
Frio. The ground in which they are imbedded has the most perfect resemblance to that
of the East Indies where the diamonds occur. It is a solid or friable conglomerate,
consisting chiefly of a ferruginous sand, which encloses fragments of various magnitude
of yellow and bluish quartz, of schistose, jasper, and grains of gold disseminated with
oligist iron ore, — all mineral matters different from those that constitute the neighbour-
ing mountains ; this conglomerate, or species of pudding-stone, almost always superficial,
occurs sometimes at a considerable height on the mountainous table-land. The most
celebrated diamond mine is that of Mandarga, on the Jigitonhonha, in the district of
Serro-do-Frio to the north of Rio -Janeiro. The river Jigitonhonha, three times bz^aader
than the Seine at P{iri8, and from 3 to 9 feet deep, is made nearly dry^ by drawing the
water off with sluices at a certain season ; and the cosco/Ao, or diamond gravel* is
removed from the channel by various mechanical means, to be washed elsewhere at
leisure. This cascalho, the same as the matrix of the gold mines, is collected in the
dry season, to be searched into during the rainy ; for which purpose it is formed into
little mounds of 15 or 16 tons weight each. The washing is carried on beneath an
oblong shed, by means of a stream of water admitted in determinate quantities
into boxes containing the cascalho. A negro washer is attached to each box ; in-
spectors are placed at regular distances on elevated stools, and whenever a negro has
found a diamond, he rises up and exhibits it. If it weighs 17^ carats, he receives
his liberty. Many precautions are taken to prevent the negroes from secreting the
diamonds. Each squad of workmen consists of 200 negroes, with a surgeon and an
almoner or priest.
The flat lands on either side of the river are equally rich in diamonds over their whole
surfkce, so that It becomes very easy to estimate what a piece of groand not yet washed
may produce.
It is said that the diamonds surrounded by a greenish crust are of the Jirst water,
or are the most limpid when cut The diamonds received in the different mines of the
district, are deposited once a month in the treasury of Tejuco ; and the amount of what
DIAMOND. 17
vas tlios delivered ftom 1801 to 1606, may be estimated at about 18 or 19 thoosand
carats f)er ojuitan.
On the banks of the torrent called Rio-Pardo, there is another mine of diamonds.
The ground presents a great many friable rocks of padding-stone, distributed in invgu lar
strata. It is chiefly in the bed of this stream that masses of cascalho occur, peculiarly
rich in diamonds. They are much esteemed, particularly those of a greenish-blue colour.
The ores that accompany the diamond at Rio-Pardo differ somewhat from those of the
washing grounds of Mandanga, for they contain no pisiform iron ore ; but a great
many pebbles of slaty jasper. This table land seems to be very high, probably not less
than 5,500 feet above the level of the sea.
Toeaya, a principal village of Minas* Novas, is 84 leagues to the north-east of Tej aeo,
in an acute angle of the confluence of the Jigitonhonlui and the Rio-Grande. In the
bed of the streamlets which fidl westward into the Jigitonhonha, those rolled white
topaxes are found which are known under the name of minoff moras with blve iopazes^ and
aquamarine beryls. In the same country are found the beautiful cymophanes or chry-
soberyls so much prized in Brazil. And it is from the cantons of Indaia and Abaite
that the largest diamonds of Brazil come ; yet they have not so pure a water as those
of the district of Serro-do-Frio, but incline a little to the lemon yellow.
It is known that numy minerals become phosphorescent b^ heat, or exposure to the
tun's light Diamonds, it has been said on doubtful authority, possess this property,
but all not in equal degree, and certain precautions must be observed to make it mani-
fest Diamonds need to be exposed to the sunbeam for a certain time in order to
become self-luminous ; or to the blue rays of the prismatic spectrum, which augment
still more the faculty of shining in the dark. Diamonds susceptible of phosphorescence
exhibit it either after a heat not raised to redness, or the electric discharge. Many
minerals possess the power of becoming electrically phosphorescent, which do not
appear to be affected by the solar rays. Diamonds possess not only a great refractive
power in the mean ray of light, but a high dispersive agency, which enables them to
throw out the most varied and yivid colours in multiplied directions.
Diamonds take precedence of every gem for the purpose of dress and decoration \
and hence the price attached to those of a pure water increases in so rapid a proportion,
that, beyond a certain term, there is no rule of commercial valuation. The largest
diamond that is known seems to be that of the Rajah of Mattan in the East Indies.
It is of the purest water, and weighs 867 carats, or, at the rate of 4 grains to a carat,
upwards of 3 ounces tro^. It is shaped like an egg, with an indented hollow near
the smaller end ; it was discovered at Landak about 100 years ago ; and though the
possession of it has cost several wars, it remained in the Mattan family for 90 years.
A governor of Batavia, after ascertaining the qualities of the gem, wished to be the
purchaser, and offered 150,000 dollars for it, besides two war brigs with their guns and
ammunition, together with a certain number of great guns, and a quantity of powder
and shot Bat this diamond possessed such celebritv in India, being regarded as a
talisman involving the fortunes of the Rijah and his family, that he refused to part with
It at any price.
The Mogul diamond passed into the possession of the ruling family of Kabul, as
has been invariably affirmed by the members of that family, and by the jewellers
of Delhi and Kabid. It has been by both parties identified with the great diamond
DOW known under the name of the Kou-i-Noor, or iNoimtom of light, — which was
displayed by its present proprietor, her Majesty the Queen, at the Great Exhibition
in 1851.
The diamond denominated the Koh-i-noor, or Mountain (koh) of Light (noor),
has long enjoyed both Indian and European celebrity, and has accordingly been the
subject of traditionary Ihble, as well as of historical record.
According to Hindu legend, it was found in the mines of the south of India in the
days of the Great War, the subject of the heroic poem, the Maha'bha'raia, and was
worn by one of Uie warriors who was slain on that occasion, Kama, king of Anga:
this would place it about 4000 years ago, or 2100 n. a A long interval next makes
it the property of Yikramaditya, the raja of M(jayin, 56 b.c., fh>m whom it
descended to his successors, the ngahs of Malwa, until the principality was subverted
by Mohamedan conquerors, into whose hands it fell, with other spoils of infinite value.
Whatever may be thought of the legend which gives so high an antiquity to the Koh-
i-Noor, we might expect some more trustworthy information when we come down so
low as the beginning of the fourteenth century ; Malwa having been invaded and
overrun by the armies of Ala-ad-din, the sultan of Delhi, in 1306, who, according to
the autobiography of the sultan Baber^ acquired the jewel. That it did become the
property of the sultanas of Delhi is little doubtful, but when or bow is matter of some
uncertainty, although the grounds of the difficulty have not hitherto been investigated.
Vol. II. C
18 DIAMOND.
In 1665 Mods. Jean Baptiste Tavernier, an enterprising and intelligept trareller,
and an eminent jeweller, although Ecnyer, Baron d'Anbonne, yisited India especially
to purchase diamonds. His profession and his personal character seem to have re-
commended him to the favourable attention of the nobles of the court of Delhi, and
bigot as he was, of Aurangseb himself, by whose commands Mons. Tavemier was
permitted to inspect, handle, and weigh the jewels of the imperial cabinet. Amongst
them was one which for surpassed all the rest in siae and value. Tavemier describes
it as rose-cut, of the i^pe of an egg cut in two, of good water, and weighing 319^
ratis, which, he says, is equal to 280 of our carats.
There is but little doubt that the diamond examined by TaTcmier in the Delhi
Cabinet was the Koh-i-Noor. BabeT, the Mogul emperor, obtained a diamond, cor-
responding exactly with this, and it paseed eventually into Uie possession of the ruling
family of Kabul Nadir Shah, on his occapation of Delhi in 1 739, compelled Mohammed
Shah, the great-grandson of Aurangseb, to give up to him everything of value that the
imperial treasury possessed, and his biographer and secretary specifies a pahAask, or
present, by Mohammed Shah to his conqueror of several magnificent diamonds.
According to the funily and popular tradition Mohammed Shah wore the Koh-i-Noor
in front of his turban at his interview with his conqueror, who insisted on exchanging
turbans in proof of his regard. However this might have been, we need have little
doubt that the great diamond of Aurangseb, was in the possession of Mohammed
Shah at the time of the Persian invasion i and if it was, it most certainly changed
masters, and became, as is universally asserted, the property of Nadir Shah, who is also
said to have bestowed upon it the name of Koh-i* Noor. After his death, the diamond
which he had wrested from the unfortunate representative of the house of Timur, became
the property of Ahmed Shah, the founder of the Abdali dynasty of Kabul, having been
given to him, or more probably taken by him, from Shahrikh, the young son of Nadir.
The jewel descended to the successors of Ahmed Shah, and when Mr. Elphinstone was
at Peshawur, was worn by Sh^ Shqja on his arm. When Shah Shiga was driven from
Kabul, he became the nominal guest and actual prisoner of Runjet Sing, who spared
neither importunity nor menace, until, in 1813, he compelled the fugitive monarch to
resign the precious gem, presenting him on the occasion, it said, with a lakh and
25,000 rupees, or alMut 12,000^ sterling. According to Shah Shiga's own aocoont,
however, he assigned to him the revenues of three villages, not one rupee of which he
ever realised. Rui^et was highly elated by the acquisition of the diamond, and wore
it as an armlet at all great festivals. When he was dying, an attempt was made by
persons about him to persuade him to make the diamond a present to Jagannnth,
and it is said that he intimated assent by an inclination of his head. The treasurer,
however, whose charge it was, refused to give it up without better warrant, and
Runjet dying before a written order could be signed by him, the Koh-i- Noor was
preserved for awhile for his successors. It was occasionsdly worn by Rhurreuk Sing
and Shu Sing. After the murder of the latter, it remained in the Lahore treasury
until the supercession of Dhulip Sing, and the annexation of the Puyaab by the
British Government, when the civil authorities took possession of the Lahore treasury,
under the stipulations previously made, that ail the property of the state should be
confiscated to the East India Company, in part payment <^ the debt due by the Lahore
government and of the expenses of the war ; it was at the same time stipulated that
the Koh-i- Noor should be presented to the Queen of England. Such is the strange
history of certainly one of the most extraordinary diamonds in the world. After the
Company became possessed of the gem, it was taken in charge by Lord Dalhousie,
and sent by him to England in custody of two officers.— fTant** Handbook of the Great
ExkibitwnqflSbl.
As exhibited at the Crystal Palace in Hyde Park, the Koh-i-Noor weighed 186^^
carats.
The form of the Koh-i-Noor is given in fig. 644. P is a large plane at the base of
the diamond which is a cleavage plane, f, also a large cleavage plane, produced by
a fructure ; this had not been polished, and being inclined to Uie plane p at an angle
of 109° 28', affords a satisfactory means for determining the diiection of the cleavage
planes of the stone. ▲ shows a flaw running parallel to tiie cleavage plane f. This
constituted the principal danger to be apprehended in cutting the stone, and was most
skilfully ground nearly out before any of the fnceta were cut. This flaw seemed to
proceed fh>m a fracture marked b. c and b were little notches cut in the stone for the
purpose of holding the diamond in its original setting ; n a small flaw which slmost
required a glass to see it, evidently parallel to the plane p ; d a fracture from a blow
or fall, showing at its base a cleavage plane — Tennant
This fine diamond did not possess that high degree of brilliancy which was expected
from its great reputation; it was consequently submitted to Messrs. Garrard to be
recut. In the operation the weight was reduced more than one-third, but its brilliancy
DIAM019D.
19
greatly improred. The present state of the Koh-1-Noor k shown infy$. 645 and
646. See DiAvomMTurrnra
644
After this gem, the next are: — 1. That of the emperor of Russia, hoagfat by the
late empress Oitharine, whteh weighs 199 earats. It is said to be of the siae of a
pigeon's egg^ and to hare been bought for 90,000^, besides an annuity to the Greek
merchant of 4,000/L It is reported that the aboTe diamond formed one of the eyes of
the famons statne of Sherigan, in the temple of Brama, and that a French grenadier,
who had deserted into the Malabar senriee, found the means of robbing the pagoda of
tius preckms gem, and escaped with it to Madras, where he disposed of it to a ship
captain for 2,0002., who resold it to a Jew for 12,0002^ From him it wae transferred
lor a large sum to the Ored: merchant 2. That of the emperor of Austria, ^hich
weighs 139 esrats, and has a slightly yellowish hue. It has, howerer, been valued at
1 00,000c 3. That of the French State, called the Regent or Pitt diamond, remarkable
for its form and its perfSect limpidity. Although it weighs only 136 carats, its fine-
qualities hare cansed it to be rained at 160,000/., Oiongh it cost only 100,000/.
The largest diamond furnished by Brazil, now in possession of the Crown of Portugal,
wdghs, according to the highest estimates, 120 carats. It was found in the streamlet
of Abaite, in a clay-slate district
Diamonds poss^sed of no extraordinary magnitude, but of a good form and a
pore water, may be Talned by a certain standard rule. In a brilliant, or rose- diamond
of regular proportions so much is cut away that the weight of the polished gem does
not exceed one-half the weight of the diamond in the rough state ; whence the ralue of
a cut diamond is esteemed equal to that of a similar rough diamond of double weight
exclusiTe of the cost of workmanship. Hie weight and yalue of diamonds is reckoned
by carats of 4 grains each ; and the comparative value of tiiro diamonds of equal
quality, but different weights, is as the squares of these iveights respectively. The aver-
age price of rough diamonds that are worth working, is about 2/. for one of a single
carat ; but as a polished diamond of one carat must have taken one of tiiro carats, its pnce
in the rough state is double the square of 2iL, or 8JL Therefore to estimate the value
of a wrought diamond, ascertain its iveight in carats, double that weight, and multiply
the square of tibis product by 2/. Hence, a wrought diamond of
1 carat is worth £S 7 carats is worth £S93
2 M 32 8 „ 512
8 ^ 72 9 „ 612
4 „ 128 10 M 800
5 „ 200 20 « 3200
6 „ 288
beyond whieh weight the price can no longer rise m this geometrical progression, from
the sbmH number of purchasers of such expensive toys. A very trifling ^ot or flaw of
any kind lowers exceedingly the commercial value of a diamond.
Diamonds are used not only as decorative gems, but for more nseAil purposes, aa
ibr cutting glass by the glazier, and all kinds of hard stones by the lapidary.
(Hi tiie structure of the glaaier's diamcmd we possess some very interesting obsenr*
c2
20
DIAMOND CUTTING.
ations and reflections by Dr. Wollaston. He remarks, that the hardest sahstances
brought to a sharp point scratch glass, indeed, bat do not cat it, and that diamonds
alone possessed that property ; which he ascribes to the peculiarity of its crystallisation
in rounded fi&ces, and curvilinear edges. For glass-cutting, those rough diamonds are
always selected which are sharply crystallised, hence called diamond sparks ; bat cat
diamonds are never used. The mclination to be giyen to a set diamond in catting
fflass is comprised within very narrow limits ; and it ought, moreover, to be moved
m the direction of one of its angles. The curvilinear edge adjoining the curved fkces,
entering as a wedge into the furrow opened up by itself, thus ten& to separate the
parts of the glass; and in order that the crack which causes the separation of the
vitreous particles may take place, the diamond must be held almost perpendicular to
the surface of the glass. The Doctor proved this theory b^ an experiment. If, by
suitable catting with the wheel, we maJLC the edges -of a spmel ruby, or corundom-
telesie (sapphire), curvilinear, and the adjacent ftices carved, these stones will cut glass
as well as a glazier*s diamond, but being less hard than it, they will not preserve this
property so long. He found that npon giving the surface of even a fragment of flint
the same shape as that of the catting diamond, it acquired the same property ; bat«
from its relative softness, was of little duration. The depUi to which the fissure
caused by the glazier's diamond penetrates does not seem to exceed the two-hundredth
of an inch.
The following remarks by Mr. Tennant cannot fail to be of interest, and, as pointing
out the errors which hare been frequently committed through ignorance, of great
value.
** By attending to the forms of the crystal, we are quite sure that we shall not find
the emerald, sapphire, zircon, or topaz in the form of a cube, octahedron, tetrahedron,
or rhombic dodecahedron ; nor the diamond^ spinel, or garnet in that of a six sided
prism, and so on with other ^ems. For want of a knowledge of the crystalline form
of the diamond a gentleman m California offered 200L for a small specimen of quartr.
He knew nothing of the substance, except that it was a bright shining mineral, exces-
sively hard, not to be scratched by the file, and which would scratch glass. Pre-
suming that these qualities belonged only to the diamond, he conceived that he was
offering a fair price for the gem ; but the owner declined the offer. Had he known
that the diamond was never found as a six -sided prism, terminated at each end by a
six-sided pyramid, he would have been able to detect the fkct that what he was offered
200il for, was really not worth more than half a crown.** — Tannanft Lecture on Geme.
The accompanying forms may serve to guide those who are ignorant of crystal-
lography.
649 BrilUant (upper side.)
e
650 Rnse.
648
DianoDd.
a, table } b, lUr-fiioets ; e, tkUl (aoets ; d, losenget ; r, giiAe.
The following technical terms are applied to the different faces of diamonds •
Bezilej the upper sides and comers of the briUiant, lying between the edge of the
table and the girdle. °
CoUei : the small horizontal plane or face, at the bottom of the brilliant.
Crown : the upper work of the rose, which all centres in the point at the top, and
18 bounded by the horizontal ribs.
Facets .• small triangular faces, or planes, both in briUianU and roses. In briUianU
there are two sorts, tA«o or jAtff-facets, and tfor-facets. Skill-iacets are divided into
iqtper and wider. Upper skill-fiieets are wrought on the lower part of the bezil, and
terminate m the girdle ; under-skill facets are wrought on the pavUions, and tenninate
in the girdle ; star-fecets are wrought on the upper part of the bezil and terminate in the
table.
Girdle : the line which encompasses the stone parallel to the horizon ; or, which
determines the greatest horizontal expansion of the stone.
DIAMOND-CUTTING. 21
Jjozemge* i are common to brUHanU and roM«. In brittianta they ar^ formed by the
meedng of the skUl and star-facets on the heziL In ratei by the meeting of the facets
in the horisontal ribs of the crown.
PaviUoma : the nnder sides and comers of briUianU, lying between the girdle and
the collet.
Bibt : the lines, or ridges, which distingnish the several parts of the work, both in
brWiamtt and nuet.
TtMe : the large horiaontal plane, or fiice, at the top of the hrUUanL
Ftg, 649 represents a brilliant, and/w. 650 a rose oat diamond.
The rose diamond is flat beneath, like all weak stones, while the upper fkce rises
into a dome and is cnt into facets. Most usaally six fiiceta are pot on the central
region which are in the form of triangles, and nnite at their summits ; their bases
abut opon another range of triangles, which bein^ set in an inverse position to the
preceding, present their bases to them, while their summits terminate at the sharp
margin ci the stone. The latter triangles leave spaces between them which are like-
wise cot each into two facets. By this distribution the rose diamond is cut into
24 facets; the surface of the diamond being divided into two portions, of which the
upper is called the crown, and that forming the contour, bennUi the former, is called
dmtdk (laoe) by the French artists.
According to Mr. Jeiferies, in his Treatise on Diamonds, the regular rose diamond
is formed by inscribing a regular octagon in the centre of Uie table side of the stone,
and bordering it by eight right-angled trisngles, the bases of which correspond with
the sides of Uie octagon ; beyond these is a chain of 8 trapeziums, and another of
16 triangles. The collet side also consists of a minute central octagon, fVom tyetj
Single of which proceeds a ray to the edge of the girdle, forming the whole surface
into 8 trapeziumSt each of which is again subdivided by a salient angle (whose apex
tonches the girdle) into one irregular pentagon and two triangles.
To fashion a rough diamond into a brilliant, the first step is to modify the faces of
the original octahedron, so that the plane formed by the junction of the two pyramids
shall be an exact square, and the axis of the cr3rstal precisely twice the length of one
of the sides of the square. The octahedron being ^us rectified, a section is to be
made parallel to the common base or girdU^ so as to cut off 5 eighteenths of the whole
height from the upper pyramid, and 1 eighteenth from the lower one. The superior
and larger plane thus produced is called the taUc^ and the inferior and smaller one is
called the adlet; in this state it is termed a complHe aquare table diamond. To convert
it into a brilliant, two triangular facets are jrfaced on each side of the table, thus
changing it from a square to an octagon ; a losenge-shaped fiioet is also placed at each
of the four comers of the table, and another loienge extending lengthwise along the
whole of each side of the original square of the table, which with two triangular meets
set on the base of each lozenge, completes the whole number of &cet8 on the table
side of the diamond ; viz. 8 lozenges, and 24 triangles. On the collet side are formed
4 irregular pentagons, alternating with as many irregular lozenges radiating from
the coUet as a centre, and bordered by 16 triangular facets adjoining the girdle. The
brilliant being thus completed, is set with the table side uppermost and the collet side
implanted in the cavity made to receive the diamond. The brilliant is always three
times a» thick as the rose diamond. In France, the thickness of the brilliant is set
(iff into two unequal portions ; one third is reserved for the upper part or table of the
diamond, and the remaining two thirds for the lower part or collet (culasae). The
table has eight planes, and its circumference is cut into facets, of which some are
triangles and others lozenges. The collet is also cut into fkcets called pavilions. It
is (if consequence that the pavilions lie in the same order as the upper fiicets, and that
they correspond to each other, so that the symmetry be perfect, for otherwise the
play of the light would be false.
Although the rose-diamond projects bright beams of light in more extensive propor-
tion often than the brilliant, yet the latter shows an incomparably greater play, from
the difference of its cutting. In executing this, there are formed 32 faces of different
figures, and inclined at different angles all round the table, on the upper side of the
stone. On the coBet (culasse) 24 other faces are made round a small table, which
converts the culasse into a truncated pyramid. These 24 facets, like the 82 above,
are differently inclined and present different figures. It is essential that the fifices of
the top and the bottom correspond together in sufficiently exact proportions to multi-
ply the reflections and refhictions, so as to produce the colours of the prismatic
speetTum.
DIAMONDS, cutting of. Although the diamond is the hardest of all known sub-
stances, yet it may be split by a steel tool, provided a blow be applied ; but this requires
a perfect knowledge of the structure, because it will only yield to such means in certain
directions. This circumstance prevents the workman from forming facettes or planes
c 3
22 ftlAMOND CUTTING.
generally, by the procesfl of splitting ; be is tberefbre obliged to resort to die process
of abrasion, whicb is technically called cutting. The process of cotting is effected by
fixing the diamond to be cut on the end of a stick, or handle, in a small ball oif
cement, that part which is to be redoced being left to project. Another diamond is
also fixed in a similar manner ; and the two stones being rubbed against each other
with considerable force, they are mutually abraded, flat surfisces, or iacetteo, being
thereby produced. Other facettes are formed by shifting the diamonds into Iresh
positions in the cement, and when a sufficient number are produced, they are fit for
polishing. The stones, when cut, are fixed for this purpose, by imbedding them in soft
solder, contained in a small copper cup, the part or fkeette to be polish^ bein^ left
to protrude,
A flat circular plate of cast-iron is then charged with the powder produoed dnriog
the abrasion of the diamonds ; and by this means a tool is formed which is capable ai
producing the exquisite lustre so much admired on a finely -polished gem. Those
diamonds that are unfit for working on account of the impenection of their lustre or
colour, are sold, for various purposes, under the technical name of Bort Stones cf
this kind are frequently broken in a steel mortar, by repeated blows, until they are
reduced to a fine powder, which is used to charge metal plates of yarioos kinds, for
the use of jewellers, lapidaries, and others. Bort, in this state of preparation, is
incapable of polishing any gems; but it is used to produce flat surfeic^ on rubies and
other precious stones.
Fine drills are made of small splinters of bort, which are used for drilling small holes
in rubies, and other hard stones, for the use of watch-jewellers, gold and silver wire-
drawers, and others who require very fine holes drilled in such substances. These
drills are also used to pierce holes in china, where rivets are to be inserted ; also for
piercing holes in artificial enamel teeth, or any vitreous substances, however hard.
The following description furnished to Mr. Tennant, by Messrs Garrard, of the
cutting of the Koh-i-noor will fully explain the peculiar conditions of the process,
and also show that there are some remarkable differences in the physical condition of
the gem in its different planes. The letters refer to the out of the Koh-i-noor, article
DiAHONik,^. 644.
**ln cutting diamonds firom the rough, the process is so uncertain that the
cutters think themselves fortunate in retaining one-half the original weight. The
Koh-i-noor, on its arrival in England, was merely surface cut, no attempt having been
made to produce the regular form of a brilliant by which alone lustre is obtained. By
reference to the figures, which are the exact size of the Koh-i-noor, it will be clearly
understood that it was necessary to remove a large portion of the stone in order to
obtain the desired effect, by which means the apparent surface was increased rather than
diminished, and the flaws and yellow tinge were removed.
** The process of diamond cutting is effected by an horizontal iron plate of about
ten inches diameter, called a «cAjf/*, or mUl which revolves from two thousand to three
thousand times per minute. The diamond is fixed in a ball of pewter at the end of
an arm, resting upon the table in which the plate revolves ; the other end, at which
the ball containing the diamond is fixed, is pressed upon the wheel by movable weights
at the discretion of the workmen. The weight applied varies from S to 30 lbs. accord-
ing to the size of the fkcets intended to be cut The recutting of the Koh-i-noor was
commenced on July 16, 1862, His Grace the late Duke of Wellington being the first
person to place it on the mill ; the portion first worked upon was that at which the
planes p and F meet, as it was necessary to reduce the stone at that part, and so to level
the set of the stone before the table could be formed ; the intention being to turn the stone
rather on one side, and take the incision or flaw at e, and a fracture on the other side of
the stone, not shown in the engraving, as the boundaries or sides of the girdle. The
next important step was the attempt to remove an incision or flaw at c, described by
Professor Tennant and the Rev. W. Mitchell as having been made for the purpose of
holding the stone more flrmly in its setting, but pronounced by the cutters (after having
cut into and examined it) to be a natural flaw of a yellow tinge, a defect often met with in
small stones. The next step was cutting a*facet on the top of the stone immediately above
the last mentioned flaw. Here the difference in the hardness of the stone first manifested
itself; for while cutting this facet, the lapidary noticing that the work did not proceed so
fast as hitherto, allowed the diamond to remain on the mill rather longer than usual, with-
out taking it off to cool ; the consequence was, that the diamond became so hot from the
continual firiction and grater weight applied, that it melted the pewter in which it was
imbedded. Again, while cutting the same facet, the mill became so hot from the ex-
treme hardness of the stone, that particles of iron mixed with diamond powder and
oil ignited. The probable cause of the diamond proving so hard at this part is, that
the lapidary was obliged to cut directly upon the angle at which two cleavage planes
meet, cutting across ^ grain of the stone. Another step that was thus considered to
DIAMOND TOOLS. 23
be importuit by the catten was remoTing a flaw at a. Thia flaw wat not thought by
Profewor Tennant and Mr. Mitehell to be dangeroos, becaiue if it were allowed to run
accor^ng to the cleaTage, it woald only take off a small piece, which it waa necessary
to remoTe in order lo acquire the fireseat shape. The cutters, however, had an idea
that it vighi not take the desired direction, and, therefore, began to cut into it ftt>m
botih sidea, and afWrwarda directly upon it, and thus they snooeeded in getting rid of
it. ¥rhile cutting, the stone appeared to become harder and harder the furdier it was
cot into, especially jost abore the flaw at ▲, which part became so hard, that, after
working the mill at the medium rate of S400 times per minute, for six hours, little
impreaaion had been made ; the speed waa therefore increased to more than 3000, at
which rate the work gradually proceeded. When the back (or former top) of the
atone was cut. It proved to be much softer, so that a hcet was made in three hours,
which would have occupied more than a day, if the hardness had been equal to that
on the other side i nevertheless, the stone afterwards became gradually huder, especi-
ally underneath the flaw at ▲, which part was nearly as hard as that directly above
H. The flaw at n did not interfere at all with the cutting. An attempt was made to
cot out the flaw at ▲, but it was found not desirable on account of its length. The
^iffwwi*!^ was finished on September 7th, having taken thirty- eight days to cut, working
twelve hours per day without oessation." The weight of the Koh-i-Noor since cut-
tiDg is 1624 carats.
DIAMOND DUST. The use of diamond dust within a few years has increased
very matorially, on account of the increased demand for all articles that are wrought
by it, such as cameos^ intaglios, &c There has been a discovery made of the peculiar
power of dmuiond dust upon steel i it gives the finest edge to all kinds of cutlery, and
It threatened at one time to displace the hone of Hungary. Finely powdered corundum,
however, now occupies its place. It is well known that in cutting a diamond, the
dust is placed on the teeth <^ the saw— to which it adheres ; to Uits dust is to be
attributed solely the power of man to make brilliants from rough diamonds. The
dost enables the polisher to obtain the perfection of geometrical svmmetr^, which is
one of the chief beauties of the mineral, and also that adamantine polish, which nothing
can iigure or affect, save a substance of its own nature.
Diamond dust, it would appear, can now be manufectured by the agency of voltaic
electricity. See Diakond.
DIAMOND MICROSCOPES were first suggested by Dr. Goring, and have been
well executed by Mr. Pritehard. Previoos to grinding a diamond into a spherical
figure, it should be ground flat and parallel upon both sides, that by looking through
it, as opticians try mnt glass, we may see whether it has a double or triple reftvctive
power, as many have, which would render it useless as a lens. Among the different
crystalline forms of the diamond, probablv the octahedron and the cube are the only
onea that will give a single vision. It will, m many cases, be advisable to grind diamond
lenses plano-convex, both because this figure gives a low spherical aberration, and
because it saves the trouble of grinding one side of the gem. A concave tool of cast
iron, paved with diamond powder, hammered into it by a hardened steel punch, was
employed by Mr. Pritehard. This ingenious artist succeeded in completing a double
convex of equal radii, of about ^ of an inch fooos, bearing an aperture of ^ of an inch
with distinctness upon opaque objects, and its entire diameter upon transparent ones.
This lens gives vision with a trifling chromatic aberration ; in other respects, like Dr.
G^ing^s Amician reflected, but without its darkness, its light is sud to be superior
to that of any compound microsc<^ whatever, acting with the same power, and the
aame an^le of aperture. The advantage of seeing an olgect without aberraium by the
interposition of only a single magnifier, instead of looking at a picture of it with aii
eye-glass, is evident We thus have a simple direct view, whereby we shall see more
accurately and minutely the real texture of objects.
DIAMOND TOOLS. 1. Tftc G&utsr't diamond is the natural diamond, so set that
one of its edges is brought to bear on the glass.
The extreuM point of any diamond will scratch ghiss, making a white streak ; but when
the rounded edge of a diamond is slid over a sheet of glass with but slight pressure,
it produces a cut, which is scarcely visible, but which readily extends through the mass.
Dr. WoUaston succeeded in ^vmg to the ruby, topaa, and rock crystal forms similar
to those of the diamond, and with thoae he succeeded in cutting glass ; proving that this
useftd property of ihe diamond depended on its form. Although die primitive form
of the diamond is that of a regular octahedron, the Dnke de Boumon has published
upwards of one hundred forms of crystallisation of the diamond. The irregular octa-
hedrona with round feeets are those proper for glaaiers* diamonds.
Notwithstanding the hardness of the diamond, yet, in large glass works, as many as
one and two doaens are worn out every week : from being convex, they become rapidly
concave, and the catting power is lost.
c4
24 PIES FOR STAMPING.
3. Diamond driUs are made of various shapes ; these are either found amongst im-
perfect diamonds, or, are selected from fragments split off from good stones in their
manufactare for jewelling.
DIAPER is the name of a kind of cloth, used chiefly for table linen. It is known
among the French by the name of ioiiefourri, and is ornamented with the most exten-
sive figures of any kind of tweeled doth, excepting damask. The mounting of a loom
for working diaper is, in principle, much the same as a draw-loom, but the figures being
less extensive, Uie mounting is more simple, and is wrought entirely by the weaver,
without the aid of any other person. As tweeled cloths, of any number of leayes, are
only interwoven at those intervals when one of the leaves is raised, the woof above and
the warp below are kept floating or flushed, until the intersection takes place. Of con-
sequence the floating yam above appears across the fabric, and that below k>ngitudi-
nally. This property of tweeled cloths is applied to form the ornamental figures of
all kinds of tweeled goods, merely by reversing the floating yam when necessary. In
the simpler patterns, this is effected by a few additional leaves of treddles ; bat when
the range of pattern becomes too great to render this convenient, an apparatus called a
back hameu is employed, and the doth woven with this mounting is called diaper.
Diapers are generally five-leaf tweels, that is to say, every warp floats under foar
threads of woof, and is raised, and of course interwoven with the fifth. This is done
either successively, forming diagonals at 45^ upon the cloth, or by intervals of two
threads, which is called the broken tweeL The latter is generally, if not uniyersally,
adopted in the manufacture of diaper. The reason of preferring the broken to the
regular tweel, where ornaments are to be formed, is very obvious. The whole depend-
ing upon reversed flushing, to give the appearance of oUique or diagonal lines through
either, would destroy much of the effect, and materially injure the beauty of the fitbric.
The broken tweel, on the contrary, restores to the tweeled doth a great similarity of
appearance to plain or alternately interwoven fabrics, and at the same time preserves
the facility of producing ornaments by reversing the flushing.
DIASTASE. A white and tasteless substance, obtained by moistening pounded
malt, and squeezing the water through a bag. Albumen is precipitated from the torbid
fluid by alcohol, and filtered. Then the diastase is precipitated by an additional qoao-
tity of alcohol, and purified by re-solution and re-precipitation. One part of diastase
will convert 2000 parts of starch into dextrine, and 1000 parts into sugar.
DICHROISM. The property of exhibiting two colours. Many of the phenomena
belong to the conditions producing Fluorescence, which see. Some of Uie pheno-
mena have been referred to polarisation, but this requires examination.
DIDYMIUM (Di). A metal discovered by Mosandar, in 1841, in oxide of cerium^
and so called as being associated in that ore as a twin brother with lanthantim»
The oxide of Didymium (DiO) is a dark brown powder ; the salts are pink, or rose,
and amethyst or violet
DIES FOR STAMPING. (Cotiu, Fr.; MUnzstampdR, Germ.) The first circum-
stance that claims particular attention in the manufacture of dies, is the selection of
~ the best kind of steel for the purpose, and this must in some measure be left to the
experience of the die-forger, who, if well skilled in hb art, will be able to form a tole-
rably correct judgment of the fitness of the metal for the purpose, by the manner in
which it works upon the anvil. It should be rather fine-grained than otherwise, and
above all things perfectly eren and uniform in its*texture, and free ttom spots and
patches finer or coarser than the general mass. But the very fine and uniform steel
with a silky fracture, which is so much esteemed for some of the purposes of cutlery,
is unfit for our present purpose, from the extreme facility with which it acquires great
hardness by pressure, and its liability to cracks and flaws. The Tery cross-grain^, or
highly crystalline steel, is also equally objectionable ; it acquires fissures under the
die-press, and seldom admits of being equally and properly hardened. The object,
therefore, is to select a steel of a medium quality as to fineness of texture, not easily
acted upon by dilute sulphuric acid, and exhibiting an uniform texture when its surface
is washed over with a little aquafortis, by which its freedom from pins of iron, and
other irregularities of composition, is sufficiently indicated.
The best kind of steel b^ing thus selected, and properly forged at a high heat into
the rough die, it is softened by very careful anneiding, and in that state, having been
smoothed externally, and brought to a table in the turning lathe, it is delivered to the
enjpraver.
The process of annealing the die consists in heating it to a bright cherry red,
and suffering it to cool gradually, which is best effected by bedding it in a cradble
or iron pot of coarsely-powdered charcoal In this operation it is sometimes sup-
nosed that the die, or at least its superficial parts, becomes super-carbonised, or
nighly converted steel, as it is sometimes called; but experience does not justify
such an opinion, and I belieye the composition of the die is scarcely, certainly not
DIES FOR STAMPING. 25
materially, affected by the process, for it does not remain long enough in the fire for
the purpose.
The engTEver nsnally commences his labours by workii:^ oat the device with small
ateel tools in intaglio ; he rarely begins in relief (though this is sometimes done) ; and
haring ultimately completed his design, and satisfied himself of its general effect and
correctness, by impressions in clay, snd dabs, or casts in type metal, the die is ready
for the important operation of hardening, which, from rarioos causes, a few of which
I shall enumerate, is a process of much risk and difficulty ; for should any accident
now occur, the labour of many months may be seriously iojored, or even rendered
quite useless.
The process of hardening soft steel is in itself very simple, though not very easily
explained upon mechanical or chemical principles. We kjiow by experience, that it
is a property of this hiffhly valuable substance to become excessively hard, if heated
and suddenly cooled ; i^ therefore, we heat a bar of soft malleable and dactile steel red
hot, and then suddenly quench it in a large quantity of cold water, it not only becomes
haid, but fragile and brittle. But as a £e is a mass of steel of considerable dimen-
sions, this hardening is an operation attended by many and peculiar difficulties, more
especially as we have at the same time to attend to the careful preservation of the
engraving. This is effected by covering the engraved face of the die with a protecting
face, composed of fixed oil of any kind, thickened with animal charcoal : some per-
sons add pipe-clay, others use a pulp of garlic, but pure lamp-black and linseed oil
answer the purpose perfectly. This is thinly spread upon the work of the die, which,
if requisite, may be fhrther defended by an iron ring ; the die is then placed with its
face downwards in a crucible, and completely surrounded by animal charcoal It is
heated to a suitable temperature, that is, about cherry red, and in that state is taken
out with proper tongs, and plunged into a body of cold water, of such magnitude as not
to become materially increased in temperature ; here it is rapidly moved about, until
aJl noise ceases, and then left in the water till quite cool. Li this process it should
produce a hobbling and hissing noise ; if it pipes and sings, we may generally appre-
hend a crack or fissure.
No process has been found to answer better than the above simple and common mode
of hardening dies, though others have had repeated and fair trials. It has been pro-
posed to keep up currents and eddies of cold water in the hardening cistern, by means
of delivery -pipes, coming fW>m a height; snd to subject the hot die, with its face
uppermost, to a sudden and copious current of water, let fall upon it ftxnn a large pipe,
supplied from a high reservoir ; but these means have not in any way proved more
successful, either in saving the die, or in giving it any good qualities. It will be recol-
lected, fVom the form of the die, that it is necessarily only, as it were, case-hardened,
the hardest strata being outside, and the softer ones within, which envelope a core,
something in the manner of the successive coats of an onion ; an arrangement which
we sometimes have an opportunity of seeing displayed in dies which have been smashed
by a violent blow.
The hardening having been effected, and the die being for the time safe, some fur-
ther steps may be taken for its protection ; one of these consists in a very mild kind of
tempering, produced by putting it into water, gradually raised to the boiling point,
till heated throo^^out, and then suffering it gradually to cooL This operation renders
the die less apt to crack in very cold weather. A great safeguard is also obtained by
thrusting the cold die into a red-hot iron ring, which just fits it in that state, and which,
by contracting as it cools, keeps its parts together under considerable pressure, pre-
venting the spreading of external cracks and fissures, and often enabling us to employ
a split or die for obtaining punches, which would break to pieces without the protecting
ring.
If the die has been successfully hardened, and the protecting paste has done its duty
by preserving the face from all injury and oxidisement, or burning, as it is usually
colled, it is now to be cleaned and polished, and in this state constitutes what is
technically called a katbix ; it may of course be used as a multiplier of medals, coins,
or impressions, but it is not generally thns employed, for fear of accidents happening
to it in the coining press, and because the artist has seldom perfected his work upon
it in this state. It is, therefore, resorted to for the purpose of fUmishing a punch,
or steel impression for relief. For this purpose a proper block of steel is selected, of
the same quality, and with the same precautions as before, and being carefully annealed,
or softened, is turned like the matrix, perfectly true and fiat at the bottom, and ob«
tusely conical at top. In this state, its conical surface is carefully compressed by
powerful and proper machinery upon the matrix, which, being very hard, soon allows
it to receive the commencement of an impression ; but in thus receiving the impres-
sion, it becomes itself so hard by condensation of texture as to require during the
operation to be repeatedly annealed, or softened, otherwise it would split into small
26 DIGESTER.
saperfioial fi8SU|e«, or vould iigare the matrix; much practical skill ia therefore
quired in taking the impression, and the panch, at each annealing, must be carefnlly
protected, so that the work may not be ii\jured.
Thus, after repeated blows in the die-press, and frequent annealing, the impresstoii
from the matrix is at length perfected, or brought completely up, and having been
retouched by the engraver, is turned, hardened, and collared, like the nuitrix, of
which it is now a complete impression in relief, and, as we have before said, is called a
punch.
This punch becomes an inexhaustible parent of dies, without fbrther reference to the
original matrix ; for now by impressing upon it pluj;s of soft steel, and by pursuing
with them an exactly similar operation to that by which the punch itself was obtained,
we procure impressions from it to any amount, which, of course are fao-similes of the
matrix, and these dies being turned, hardened, polished, and, if necessary, tempered,
are employed for the purposes of coinage.
The distinction between striking medals and common coin is very essential, and the
work upon the dies is accordingly adjusted to each. Medals are usually in very high
relief, and the effect is product by a succession of blows ; and as the metal in which
they are struck, be it gold, silver, or copper, acquires considerable hardness at each
stroke of the press, they are repeatedly annealed during the process of bringing
them up. In a beautifhl medal, which Mr. Wyon executed for the Ro^al Naval
College, the obverse represents the head of the King, in very bold relief; it re-
quired thirty blows of a very poweriUl press to complete the impression, and it was
necessary to anneal each medal after every third blow, so that they went ten times into
tiie fire for that purpose. In striking a coin or medal, the lateral spread of the metal,
which otherwise would ooae out as it were from between the dies, is prevented by the
application of a steel collar, accurately turned to the dimensions of the dies, and which,
when left plain, gives to the edge of the piece a finished and polished appearance ; it is
semetimes grooved, or milled, or otherwise ornamented, and occasionally lettered, in
which case it is made in three separate and movable pieces, confined by a ring, into
which they are most accurately fitted, and so a(](justed that the metal may be forced
into the letters by its lateral spread, at the came time that the coin receives the blow
of the screw- press.
Coins are generally completed by one blow of the coining-press. These presses are
worked in the Royal Mint by machinery, so contrived that they shall strike, upon an
average, sixty blows in a minute ; the blank piece, previously properly prepared and
annealed, being placed between the dies by part of the same mechanism.
The number of pieces which may be struck by a pair of dies of good steel, pro-
perly hardened and duly tempered, not unfrequently amounts at the Mint to between
one and two hundred thousand ; but the average consumption of dies is of course much
greater, owing to the variable qualities of steel, and to the casualties to which the dies
are liable; thus, the upper and lower die are sometimes struck together, owing to
an error in the layer-on, or in that part of the machinery which ought to put the blank
into its place, but which now and then fails so to do. This accident very commonly
arises from the boy who superintends the press neglecting to feed the hopper of the
layer-on with blank pieces. If a die is too haid, it is apt to break or split; and is es-
peciallv sulject to fissures, which run from letter to letter upon the edge. If too soft,
it swells, and the collar will not rise and fall upon it, or it sinks in the centre, and the
work becomes distorted and fknlty. He, therefore, who supplies the dies for an exten-
sive coinage, has many accidents and difficulties to encounter. There are eight presses
at the Mint, frequently at work for ten hours each day, and the destruction of eight
pair of dies per day (one pair for each press) may be considered a fhir average result,
though they much more frequently fall short of, than exceed this proportion. It must
be remembered, that each press produces 3600 pieces per hour ; but making allowance
for occasional stoppages, we may reckon the daily produce of each press at 30,000
pieces ; the eight presses, therefore, will frimish a diurnal average of 240,000 pieces.
DIES, hardening of. See Stkel, hardening of.
DIGESTER is the name of a copper kettle or pot of small dimensions, made very
strong, and mounted with a safety valve in its top. Papin, the contriver of this appa-
ratus, used it for subjecting bones, cartilages, &c. to the solvent action of high -pressure
steam, or highly heated water, whereby he proposed to ftusilitate their digestion in
the stomach. This contrivance is the origin of the French cookery pans, called
autochv€8, because the lid is self-keyed, or becomes steam-tight bv turning it round
under damps or ears at the sides, having been previously ground with emery to fit the
edge of the pot exactly. In some autoclaves the lid is merely laid on with a fillet of
linen as a lute, and then secured in its place by means of a screw bearing down upon
its centre from an arched bar above. The safety valve is loaded either by a weight
placed vertically upon it, or by a lever of the second kind pressing near its fulcrum,
DISINFECTANT. 2t
mnd aeted upon by a weight which may he made to bear upon any point of its gra-
duated arm.
CheTTeoi has made a naefiil application of the digeeter to Tegetable analyaif. Hib
instrnraent conaists of a strong copper eyiinder, into which enters a tight cylinder of
silTer, haying its edge tnmed oTer at right angles to the axis of the cylinder, so as to
form the rim of the digester. A segment of a copper sphere, also lined with silver,
stops the apertore of the silver cylmder, being applied closely to its rim. It has a
conical vabre pressed with a spiral spring, of any desired force, estimated by a steel-
yard. This spring is enclosed within a brass box perforated with four holes ; which
may be screwed into a tapped orifice in the top the digester. A tnbe screwed into
another hole serves to conduct away the condensible vaponrs at pleasure into a Wonlfe's
apparatosL
DIKE or DYKE. A waU like division in rocks, prodooedby the Section of trapean
matter in a fiased state ftt>m below, throogh the overlying strata. In many places
those hard trap rocks stand out above the a^acent rocks, which have been worn
away, presenting actually the appearance of a massive wall.
DILATATION. The increase of size produced in bodies by the agency of heat
See EzPANsioK.
DILUVIUM. (i>iikmaR.) Deluge. Those accumulations of gravel and loose
materials, which, by some geologists, are said to have been produced by the action of
a dilnvian wave or deluge, sweeping over the surftce of tfie earth. — LyeB.
DIMITY is a kind of cloth cotton originally imported from India, and now manu-
factured in great quantities in various parts of Britain, especii^ in Lancashire. Dr.
Johnson calls it dimmity, and describes it as a kind of ftistian. The distincUon between
fustian and dimity seems to be, that the former designates a common tweeled cotton
cloth of a stout &bric which receives no ornament in the loom, but is most frequently
dyed after being woven. Dimity is also a stout cotton doth, but not usually of so
thick a texture ; and is ornamented in the loom, either with raised stripes or fancy
figures : it is seldom dyed, but usually employed white, as for bed and bed-room furniture.
The striped dimities are the most common, they require less labour in weaving than
the others ; and the mounting of the loom being more simple, and consequently less
expensive, they can be sold at much lower rates.
DIOPTRIC LIGHTUOUSEa See Liohthoubbs.
DIORITES. A trap or greenstone rock, in which albUe replaces or^oclase.
Diorites are abundant in the Vosges.
DIP. ¥rhen any stratum, mineral vein, or dike, does not lie horisontally it is said
tod ip E. W. N. or S., as the case may be. The angle which it makes with the
horizon^ called the angle of the dip.
DIPPEL'S ANIMAL OIL. A fetid voktile oil obtuned when animal sub-
stances, such as bone, are subjected to distillation. That which is found in commerce
is obtained in the manuihcture of bone-black.
DIPPING. Ornamental works in brass aro usually brightened by a process called
dipping. After the work has been properly fitted together and the gretae removed,
'either by the action of heat, or by boiling in a pearl ash lye, it is piciled in a bath of
dilute aqua fortis. It is then scoured bright with sand and water, and being well
washed is plunged into the dipping bath, which consists of pure nitrous acid,
commonly known as dipping aquafortis^ for an instant only, and is then well washed
with cold and hot water to remove every trace of acid from the snrfkce, after which
the work is put into dry beech or box wood, sawdust, &c, well rubbed until it is quite
dry, and then burnished and lackered with as little delay as possible.
DISINFECTANT. A substance which removes the putrid or infected con-
dition of bodies. It is well not to confound it with antiseptic, which applies to
those bodies which prevent putrefaction. The word disinfectant has lately become
somewhat uncertain in its meaning, on account of a word being used as its equiva-
lent, viz. deodoriser. This latter means a substance which removes odours. In
reality, however, there are no such substances known to us as a class. There are,
of course, some substances which destroy certain others having an odour, but in all
cases the removal of the smell and the destruction or neutralisation of the body must
be simultaneous. There is, however, a large class of substances that destroy putre-
faction, and the name disinfectant is therefore distinctly needed. The gases which
rise from putrefying bodies are not all capable of bein^ perceived by the senses in
their ordinary condition, but sometimes they are perceived. A disinfectant puts a
stop to them and deodorises simultaneously. If any substance were to remove the
smell of these gases, it would remove the gases too, as they are inseparable from their
property of affecting the nose. A deodoriser would therefore be, and is, a disinfectant
of that gas the smell of which it removes. But it has been suggested that it may
remove Uiose gases which smell, and allow the most deleterious to pass, they having
no smelL Whenever we find such a class of substances, it will be well to give them
?8 DISINFECTANT.
the Dame of deodorisers. There may be fiome trath in the hypothesis that metallic
salts remove the sulphar, and by preyenting the escape of sulphuretted hydrogen cause
less odour, vithoat complete disinfection. But it appears that the decomposition is
a prevention of putrefaction in proportion to the removal of that gas in cases vhere
it is given out, and it is quite certain that metallic solutions have disinfecting proper-
ties. Any solution having the effect here supposed would at the least be a partial
disinfectant, inasmuch as tibe decomposition would be so far put a stop to, as to prevent
at least one obnoxious gas. How the others could remain unacted on in this case it is
difficult to comprehend. To prevent the formation of one gas is to arrest decom-
position or to alter the whole character of the change which is producing the
gases. The most deleterious of emanations have no smell at all to the ordinary
senses, and we can only judge of the evil by its results, or the fact that the sub-
stances capable of producing it are near, or by the analysis of the air. (See Sani-
tary Arrangehents.) The cases where sulphuretted hydrogen accompanies the
offensive matter, are chiefly connected with fgsctX decomposition. This gas is a
useful indication of the presence of other substances. So far as is known, the des-
truction of the one causes the destruction of the other. But the presence of sul-
phuretted hydrogen is no proof of the presence of infectious matter, nor is its absence
a proof of the absence of infections matter, it being only an occasional accompaniment.
When the infectious matter and the odoriferous matter are one, as in the ease, as far
as we know, of putrid flesh, &c., then to deodorise is to disinfect We can find then
no line of daty to be performed by deodorisers, and no class of bodies that can bear
the name, although there may be a few cases where the word may be found convenient.
If, for example, we destroy one smell by superadding a greater, that might in one
sense be a deodorising. If we added an acid metallic salt, and removed the sulphu-
retted hydrogen, letting loose those organic vapours which for awhile accompany
this act, we might, to those who were not very near, completely destroy smell, and
still send a substance into the air by no means wholesome ; but in such a case decom-
position is stopped, at least for a while. The smelling stage is by no means the most
dangerous, nor has the use of the word deodorise any relation to sanitary matters,
except in the grossest sense ; it is desirable that persons should look far beyond
the mere indications furnished by the nose, and as in science we can find no deodo-
risers, so in practice we need not look for any in the sense usually given to the word.
The word may be used for such substances as remove the odour and the putrefaction
of the moment, but allow them to begin again. Even in this case deodorisers become
temporary disinfectants, which character all removers of smell must more or less
have.
Antiseptics, or cclytic agents. Substances which prevent decomposition, ne words
coiysis and coiytic come from kwXuw, to arrest, restrain, cut short. This word was proposed
by the writer to apply to cases such as are included under antiseptics, antiferments,
and similar words. There was needed a word for the general idea. A colytic force
manifests itself towards living persons in anaesthetics, anodynes, and narcotics, as well
probably, as in other ways. Colytics may probably act fh>m different causes, but these
causes not bein^ separately distinguished, a name for the whole class can alone be
given. The action of coiysis is entirely opposed to catalysis, which is a loosening up
of a compound. CoUfsis arrests catalysis, as well dso as other processes of decompo-
sition, ordinary oxidation for example. Disinfectants, in their character of restraining
further decomposition, are included under colytics. One of the most remarkable sub-
stances for arresting decomposition is kreasote. It has been used in some condition or
mixture firom the earliest times. The ancient oil of cedar has been called with good
reason turpentine, which has strong disinfecting properties, but the word has evidently
been used in many senses, as there are many liquids to be obtained firom cedar. It is used
for the first liquid from the distillation of wood; and Berzelius for that reason says
that the Egyptians used the pyroligneons acid, which, containing some kreasote« was
a great antiseptic. But a mixture of this acid with soda would be of little value in
embalming, nor is it probable that they would add a volatile liquid like turpentine
along with caustic soda. It is expressly said (in Pliny) that the pitch was reboiled,
or, in other words, the tar was boiled and distilled, the product being collected in the
wool of fleeces, from which again it was removed by pressure. In doing this the
light oils or naphtha would be evaporated, and the heavy oil of tar, containing
the carbolic acid, or kreasote, would remain. It was called picenum, as if made
of pitch or pissenum, and pisselsum or pitch oil, a more appropriate name than that
of Bunge's carbolic acid or coal-oil, and still more appropriate than the most recent,
which, by following up a theory, has converted it into phenic acid. The distillation
was made in copper vessels, and must have been carried very far, as they obtained
**a reddish pitch, very clammy, and much fatter than other pitch." This was the
anthracene, chrysene, and pyrene of modem chemistry. The remaining hard pitch
was called palimpissa, or second pitch, which we call pitch in contradistinction
DISINFECTANT. 29
to tar. By the second pitch, howeyer, was somethnes meant the prodoct of distillation
instead of what iras left in the stilL Some confosion therefore exiits in the names,
bat not more than with as. The pitch oil was resinous fat, and of yellow colonr,
according to some. This oil, containing kreasote, was used for toothacne — a colytie
action applied to liying bodies •— and for skin diseases of cattle, for which it is
found yaloahle. They also osed it for preserving hams. — ('* l>inf|/0c/aato,'* by the
Writer. Jtmr. Sec, of Att», 1857.)
It is qnite possible that kreasote may be the chief agent in most empyrenmatic
aabstanoes which act as antiseptics. Bat it is not the only agent Hydrocarbons of
yarioos kinds act as antiseptics, as well as alcohol and methylic alcohol, which contain
little oxygen. To this class belong essential oils and substances termed perfumes,
which are nsed for fumigation, and haye also a powerful colytic action, it is
exceedingly probable that the true theory of this action is connected with the want
of oxygen. These substances do not rapidly oxidise, but, on the contrary, only yery
slowly, and that chiefly by the aid of other bodies. Their atoms are, therefore, in
a state of tension, ready to unite when assisted. As an example, carbolic acid and
kreasote nnite with oxygen when a base is present, and form roeolic acid. We can
scarcely suppose that an explanation, commonly resorted to in the case of sulphurous
acid, would suit them ; yiz., that it takes up the oxygen, and so keeps it from the
pntrescible substance. It is, therefore, much more hkely that its condition acts on
the putrescible body. For, as the state of motion of a putrefying substance is trans-
ferred to another, so is the state of immobility.
In 1750 Sir John Pringle wrote his ** Experiments on Septic and Antiseptic
Substances, with remarks relating to their Use in die Theory of Medicine.*' He
recommended salts of yarioos kinds, and astringent and gummy parts of yegetables
and fermenting liquors. Dr. Macbride followed him with numerous experiments.
He speaks of acids being the long prescribed agents as antiseptics. He found them
antiseptic even when diluted to a great extent. Alkalies also be found antiseptic,
and salts in generaL Also " gum-resins, such as myrrh, asafcetida, aloes, and terra
japonica," besides ** decoctions of Virginia snake-root, pepper, ginger, saffron, con-
trayerra root, sage, valerian root, and rhubarb, with mint, angelica, senna, and
common wormwood." Many of the common yegetables also were included as to
some extent antiseptic ; such as horse-radish, mustard, carrots, turnips, garlic, onions,
celery, cabbage, colewort Lime was found to prevent, but not to remove putrefac-
tion. We are inclined at present very much to qualify some of these observations.
Animal flaids, he observes, will remain for a long time without putridity if kept
firom the air. He says that astringent mineral acids and ardent spirits "not only
absorb the matter from the putrescent substances, but likewise crisp up its fibres, and
thereby render it so hard and durable that no change of combination will take place
for many years.** He adds also molasses to the antiseptics. In 1767 the academy of
DQon gave a prise for the use of nitrate of potash in ventilation. This may have gifen
the first idea to Carmicbael Smyth. Guyton-Morveau came later with a volume of
yalnable experients on adds.
An anUeeptic preserves fh>m patrefiietion, but does not necessarily remove the odour
caused by tnat which has previously putrefied. Many of the substances described as
disitdTeetants here, mij^t equally be cidled antiseptics. When they remove the putrid
matter they are disinfectants, when they prevent decomposition they are antiseptics.
Bat when the smell is removed by a substance which is known to destroy putrefactive
decomposition, and to preserve organic matter entire, then we have the most thoroush
disinfection ; then we know that the removal of the smell is merely an indication of the
removal of the evlL
IHein/eetanU are of various kinds. Nature seems to use soil as one of the most
active. AU the dejecta of the animals on the surface of the earth fall on the soil,
and are rapidly made perfectly innoxious. Absorption distinguishes porous bodies,
and the soil has peculiar facilities for the purpose. Bat if saturated, it could disin-
fect no longer. This is not allowed to occur ; the soil absorbs air also, and oxidises the
organic matter which it has received into its pores, and the offensive mister is by this
means either converted into food for plants, or is made an innocent ingredient of the air,
or, if the weather be moist, of the water. The air is therefore, in copjuuction with
the soil, one of the greatest disinfectants, but it acts also quite alone and independent of
the soil. Its power of oxidising must be very great The amount of organic effluvium
sent into large towns is remarkable, and yet it seldom accumulates so as to be
t^rcfDfly perceptible to the senses. The air oxidises it almost as rapidly as it rises ;
this IS hastened apparently by the peculiar agent in the air, oionc, which has a
greater capacity of oxidation than the common air ; when this is exhausted it is
highly probable that the oxidation will be much slower, and this exhaustion does
take place in a very short time. So rapid is the oxidation, that the wind, even
30 DISINFECTANT.
blowing at the rate of about fifteen to twenty miles an boor, iir entirely derived of
its ozone by passing over less than a mile of Manchester. In J^ondon this does not
take place so rapidly, at least near the Thames. But when the oione is removed, it is
probable that the rate of increase of the organic matter will be maeh greater. We
may by this means, then, readily gauge the condition of a town up to a certain point
by the removal of the ozone : but it requires another agent to gauge it afterwards or
thoroughly. It is in connection with each other that the air and the soil best dis-
infect When manure is thrown upon land without mixing with the soil, it may
require a very long period to obtain thorough disinfection, but when the atmosphere
is moist, or rain iaUs, then the air is rapidly transferred into every portion of the
porous earth, and the organic matter becomes rapidly oxidised. To prevent a
smell of manure, and with it also the loss of ammonia, it is then needfbl that as soon
as possible the manure should be mixed with the soil. The same power of oxidation
is common to all porous bodies, to charcoal, and especially, as Dr. Stenhouse has
shown, to platinised charcoal Disinfection by the use of porous bodies is not a pro-
cess of preservation, but of slow destruction. It is an oxidation in which all the
escaping gases are so thoroughly oxidised, that none of them have any smell or any
offensive pn^rty. But being so, the body disinfected must necessarily decay, and
in reality the process of decay is remarkabljr increased. All such bodies must there-
fore be avoided when manures are to be disinfected, as the valuable ingredients are
destroyed instead of being preserved. Stenhouse has employed charcoal for disin-
fecting the air. The air is passed through the charcoal either on a large scale for a
hospi^ or on a small scale as a respirator fbr the mouth. Care must be taken, how-
ever, to keep the charcoal dry : wet charcoal is not capable of absorbing air until that
air is dissolved in the water. This soluticm takes place less n^iidly in water. Wet
charcoal is therefore a filter for fluids chiefly, and dry charcoal fbr vapours. Its destruc-
tive action on manures will, however, always prevent charcoal fkx»m being much used
as a disinfectant for such purposes, or, indeed, any other substance wlu^ acts principally
by iu porosity or by oxidation. This the soil does only partially, as it has another
power, riz. that of retaining organic substances fit to be the food of plants. Although
air acts partly in coig unction with the soil and the ndn to cause disinnction, and partly
by its own power, it also acts mechanically as a means of removing all noxious vapours.
The wind and other currents of the air are continually ventilating the ground, and when
these movements are not sufficiently rapid, or when they are interrupted by our mode
of building, we are compelled to cause them artificially, and thus we arrive at the
art of ventilation. The addition of one tenth of a per cent of carbonic acid to the
air may be perceived, at least if accompanied with the amount of organic matter
usually given out at the same time in the breath, and as we exhale in a day 20
cubic feet of carbonic acid, we can injure the quality of 20,000 cuIhc feet of air in
that time. The great value of a constant change of air is therefore readily proved*
and the instinctive love which we have of fresh air is a sufficient corroboration.
Cold is a great natural disinfectant The flesh of animals may be preserved as far
as we know for thousands of years in ice ; putrefying emanations are completely
arrested by freezing, but the mobility of the particles, or chemical action, is also
retarded by a degree of cold much less than freezing.
Heat is also a disinfectant, when it rises to about 140^ of Fahrenheit, according to
Dr. Henry. But as a means of producing dryness it is a dinnfeotant at various
temperatures. Nothing which is perfectly dry can undergo putrefection. On the other
hand heat with moisture below 140° is a condition very highly productive of decom-
position and all its resulting evils. Disinfection by heat is used at qaarantine stationiL
Light is undoubtedly a great disinfectant} so fkr as we know, it acts by hastening che-
mical decomposition. In all cases of ventilation, it is essential to allow the rays of light
to enter with the currents of air. Its effect on the vitality of the fanmaa being is abun-
dantly proved, and is continually asserting itself in vegetation. The true disinfecting
property of light exists in all probability in the cheimcal rays which cause compo-
sitions and decompositions. Water, however, is of all natural disinfectants the most
managealA, and there is no one capable of taking its place actively. Wherever animals
even human beings, live, there are emanations of organic matter, even fh>m the purest
The whole surfhce of the house, furniture, floor, and walls, becomes coated by degrees
with a thin covering, and this gradually decomposes, and gives off unpleasant vapours^
Sometimes it becomes planted with fungi, and so feeids plants of this kind. But long
before this occurs a small amount of vapour is given off sufficiently disagreeable to
affect the senses, and sometimes affecting the spirits and the health before the senses
distinctly perceive it This must be removed. In most cases this fllm is removed by
water, and we have the ordinary result of household cleanliness ; but in other cases
when the fhmiture is such as will be injured by water, the removal is made by friction
or by oil or turpentine, and other substances used to polish. Water as a disinfectant
DISINFECTANT. 81
k wed ftteo in washing of clotheg, for this porpoie nothing whaterer can snpply its
glaoe, although it requires the assistance both of soap and friction, or agitation and
cat Water is also osed as a mechanical agent for remoring filth, and the method
which Hercules derised of nsing a river to wash away filth, is now adopted in all the
most adTBBced plans of cleansing towns. It is only b^ means of water that the refose
of towns can be conveyed away in covered and impervioas passa^pes, whilst none what-
ever is allowed to remain in the town itself. In cases where this cannot be done, it
is much to be desired that some disinfocting agent shoold be vsed to prevent dccom*
position. Where water is not nsed, as in water-eioseta, there most of course be a great
amount of matter stored up in middens, and the town is of course continually exposed
to the efilttvift. Besides these methods of acting, water disinfects partly by preventiDg
effluvia from i|rising from bodies, simply becnose it keeps them in solution. Iliis
action is not a perfect one, but one of great value. The water gives off the impurity
slowly, sometimes so iriowly as to be of no injury, or it keeps it so long that complete
oxidation takes pbMse. The oxygen for this purpose is supplied by the air, which tiie
water absorbs without ceasing. To act in this way, water must be delivered in
abundance ; when only existing as a moisture, water may act as a great opponent
to disinfeetioQ bpr rising up in vapour loaded with the products of decomposition.
Mere dry log is known to arrest deoay, as the mobility of the particles in decompo-
sition is stayed by the want of water. We are told in Andersson^ travels in 8. Africa,
that the Damarss cut their meat into strips, and dry it in the sun, by which OMuns it is
preserved fresh. A similar custom is found in 8. America. Certain days prevent <
this, and decomposition sets in rapidly. A little overclouding of the sky, or a little
more moisture in the air, quickly stops the process.
The above may be called natural disinfectants, or imitations of natural processes,
charcoal being introduced as an exam|^ of a more decided character of poroos action.
They show both mechanical and chemical action. The mechanical, when water or air
removal dilutes, or covers the septic bodies : the chemical, when porous bodies act as
conveyers of oxjgen : or an union of both, when oold and Ikeat prevent the mobilitjr of
the particIeiL The action by oxidation causes a desfcruotion of the offensive material.
The other method is antiseptic It is much to be desired that all impurities shoukl be
got rid of bv some <tf these methods, but especially by the air, the water, and the soiL
There are, however, conditions in which diffieolties interfere with the action. Large
towns may be purified by water, but what is to be done with the water which contains
all the impurity? If put upon land, it is very soon disinfected, but on its way to the
laad it may do much mischief. It has been proposed to disinfect it on its passage,
and even in the sewers themselves ; by this means the town itself is freed from Uie
nuisaaoe, and the water may be used where it is needed witibout fear. This intro-
duces artificial disinfectants. There are other cases where such are required ; when
the refuse matter of a town is allowed to lie either in exposed or in underground
receptacles; in this case a town is eiqKMed to an immense sorfece of impurity, and
dxstnfeetants would greatly diminish ^e evil, if not entirely remove it There are
besides, special cases without end continually occurring, where impurities cannot be
at once removed, and where treatment with artificial disinfectants is required.
Artificial disinfectants which destroy the compound, are of various kinds. Fire is
one of the most powerful. A putrid body, when heated so as to be deprived of all
volatile particles, cannot any longer decompose^ It is however passible that the
vapours m^ become putrid, and if not oarefolly treated, this will happen. ^ It was the
custom of some of the WMltfay among the ancients to bum the dead, and it is still the
custom in India; but although the form is kept up amongst all classM, the expense is
too great for the poor. The bodies are singed, or even less touched by nre, and
thrown if possible into the river. This process has been recommended here, but the
quality of the gaseous matter rising from a dead body, is most disgusting to our
physical, and still more to our moral senses, and the amount is enormous. It is of
course possible so to bum it, that only pure Carbonic acid, water, and nitrogen,
shall escape, but the probability of preventing all escape is small enough to be deemed
an impossibility, and the escape of one per cent would cause a rising of the whole
neighbourhood. To effect the combustion of the dead of a great city, such a laige work,
furmihed with great and powerful furnaces, would be required, that it would add one
of the most frightful blots to modem civihsation, instead of the calm and peaceM
churchyard where our bones are preserved as long at least as those who care for us live,
and then gradually return to the earth. In burning the dead some prefer to bam
the whole body to pure ash. This was the ancient method; but it is highly probable
that the ashes which Uiey obtained were a delusion in most cases. The amount of
ash found in the urns, is often extremely small. The body cannot be reduced to an
infinitesimal ash, as is supposed; eight to twelve pounds of matter remain from an aver-
age man when all is over. A seeond plan, is to drive off all volatile matter, and leave
32 DISINFECTANT.
a cinder. This disgusting plan leaves the body black and incorruptible. It can never,
in any time known to us, mix with its mother earth, and yet ceases at once to
resemble humanity in the slightest degree; it will not even for a long time assist ns
by adding its composition to the fertility of the soiL The burning of bodies never
could have been general, and never can be general. Fire has only a limited use as a
disinfectant. It cannot be used in the daily disinfection of the dejecta of animals, and
is applied only occasionally, where the most rapid destruction is the most desirable, either
because the substance has no value, or it is too disgusting to exist, or the products after
burning are not offensive. There are two methods of using fire, charring or burning
to ashes. The second is an act of
Oxidation, — This is effected either by rapid combustion called fire ; by slow com-
bustion, the natural action of the air ; or by chemical agency, sometimes assisted hy
mechanicaL Slow oxidation in the soil is a process which is desirable in every re-
spect, and it would be well if we could bring all offensive matter into this condition;
the ammonia is preserved, or it is in part oxidised into nitric acid and water, both
the ammonia and nitric acid being food for plants. Sometimes this process is hastened
by mixing up the manure with alkaline substances, raising it in heaps, and watering,
by this means forming nitrates, a process performed abundantly in warm countries
upon the materials of plants and animals, and imitated even in temperate regions with
success. This amount of oxidation destroys a good deal of the carbonaceous substances,
and leaves less for the land. It is only valuable when saltpetre is to be prepared.
One of the most thorough methods of oxidation, is by the use of the manganates or
permanganates. They transfer their oxygen to organic substances with great rapidity.
and completely destroy them. They are therefore complete disinfectants. They
destroy the odour of putrid matter rapidly, and oxidise sulphuretted hydrogen, and
phosphuretted hydrogen, as well as purely organic substances. As the^ do this by
oxidation at a low temperature, they are the mildest form of the destructive disinfec-
tants, and their application to putrid lic^uids of every kind will give most satisfiictory
results. The quantities treated at a tmie should not be great, and the amount of
material used must be only to the point of stopping the smell, or at least not much
more, because both pure and impure matter act on the manganates, and an enormoua
amount of the material may be used in destroying that which is not at all offensive.
The manganates do not prevent decay from beginning again. Their use has been
patented by Mr. Condy. A similar action takes place with various high oxides and
other oxides which are not high. Sometimes, however, a deleterious gas is produced
as a secondary result by oxidation, as when sulphuric acid in the sulphates oxidises
organic matter, allowing sulphuretted hydrogen to escape. In this case it is highly
probable that a true disinfection takes place, or a destruction of the putrid substance,
and all offensive purely organic substances; still the amount of sulphuretted hydrogen
given off, is of itself sufficiently offensive and deleterious, although not properly
speaking an infectious or putrid gas, but an occasional accompaniment.
Nitric acid is another agent of destruction or oxidation, although it has qualities
which might cause it to be ranked amongst those which prevent the decomposition by
entering into new combinations. But properly speaking, it is not nitric acid which is
the disinfectant of Carmichael Smyth, but nitric oxide, which is a powerful oxidiser,
and most rapidly destroys orj|;anic matter. For very bad cases, in which gaseous
fumigation is applicable, nothing can be more rapid and effective in its action than
this gas. Care must be taken that there is no one present to breathe it, as it has a
powerful action on the lungs, and care must be taken that metallic sur&ees which are
to be preserved clean, be well covered with a coating of varnish. This was used with
great effect in ships and hospitals for some years, beginning with 1 780, and so much
good did it do, that the Parliament in 1802 voted Dr. C. Smyth a pension for it.
Guyton-Morveau was vexed at this, and wrote an interesting volume concerning his
mode of fumigating by acids; but in reality acids alone are insufficient, and his fa-
vourite muriatic acid has no such effect as nitrous fumes, which so readily part with
their oxygen.
Cbiorme is another destructive agent, and its peculiar action may be called an
oxidation. When used as a gas, it has a great power of penetration, like nitrous fumes,
and stops all putrefaction. It has a more actively destructive power than oxygen
alone, even when its action is that of oxidation only. It decomposes compounds of
ammonia into water and nitrogen, and as putrefactive matter is united with, or com-
posed partly of nitrogen, it destroys the very germ of the evil. By the same power
it destroys the most expensive part of a manure, the ammonia. It cannot therefore
be used where the offensive matter is to be retained for manure. When chlorine is
united with lime or soda, it may be used either as a powder in the first case, or as a
liquid in either case. For direct application to the offensive substances a solution
is used, or the powder. This latter acts exactly as the gaseous chlorine, but the
DISINFECTANT. 33
pofwer of deetroying ammonia is greater. As a liquid, it acts too rapidly; as a solid,
the cbloride of lime soon attracts moisture, and soon loses its power. Some people
use the chloride of lime as a source of chlorine; they pour sulphuric acid on it, and so
cause it to giye out chlorine, which escapes as a gas, and acts as aforesaid. This has
not been found agreeable, or indeed more than partially useful. Too much is giren
out at first, too little at last It is said to have increased the lung diseases at hospitals,
where it was much used in Paris. When only a minute quantity of gas is given out,
as at bleach works, it certainly causes a peculiar freshness of feeling, and the appear-
ance of {he people is much in its favour, nor has it eyer there been known to affect the
lungs. For violent action, in cases of great impurity, it is a great disinfectant, and to
be preferred to nitrous fumes, probably causing a less powerful action on the lungs.
Eau dejacelle is a chloride of potash used in Paris. Sometimes oxygen, or at least
air, is used alone, to remoTe both colour and smell, oils haying it pumped into them.
Sometimes acids alone are used for disinfection. As putrid compounds contain am-
monia or organic bases, they may be removed, pr at least they may be retained in
combination, and in this way restrained from further evaporation. This seems to
be the way in which muriatic acid acts, and all other merely acid agents. This acid,
so much valued at one time, is now entirely disused, as it ought to be, because it is ex-
ceedingly disagreeable to breathe, and destructive of nearly all useful substances which
it touches, being at the same time a yery indirect disinfectant Acids poured on putrid
matters, no doubt destroy the true putrefiu:tion, but they cause the eyolution of gases
exceedingly nauseous, and of course unwholesome. This evolution does not last long,
but long enough to make them useless as disinfectants when used so strong. Vinegar
is the best of the purely acid disinfectants ; wood yinegar the best of the vinegars,
because it unites to the acidity a little kreasote. Vinegar is a very old and well
established agent ; it has been used in the case of plague and various pestilences from
time immemorial. It is used to preserve eatables of varioas kinds. For fumigation
no acid yaponr used is pleasant except yinegar, and in cases where the impurity is
not of the most violent kind, it may be used with great advantage. Even this how-
ever acts on some bright surfaces, a disadvantage attending most fhmigations.
Si^}hurous- add, or the fumes of burning sulphur, may be treated under this head,
although in reality it does not act as a mere acid combining with a base and doing no
more. It certainly unites with bases so that it has the advantage of an acid, but it
also decomposes by precipitating its sulphur, as when it meets sulphuretted hydrogen.
It therefore acts as an oxidiser in some cases, but it is generally belieyed, from its
desire to obtain oxygen, that it acts by being oxidised, thus showing the peculiar
characteristics of a dcoxidiser. We can certainly belieye that bodies may be disin-
fected both by oxidation and deoxidation. The solutions of sulphurous acid act as a
restraint on oxidation, and preserve like yinegar. Its compounds with bases, such
as its salu of soda, potash, &c, preserve also like vinegar, saltpetre, &c. ; probably
from their affinity for oxygen, taking what comes into the liquid before the^ organic
matter can obtain it. But it is not probable that this rivalry exists to a great extent ;
the presence of the sulphurous acid in all probability puts some of the particles of oxy-
gen in the organic matter in a state of tension or inclination to combine with it, so
that the tension of the particles which are inclined to combine with the oxygen of the
air is removed.
Sulphur fumes are amongst the most ancient disinfectants held sacred in early times
from their wonderful efficacy, and still surpassed by none. With sulphur the shepherd
purified or disinfected his flocks, and with sulphur IFlysses disinfected the suitors which
he had slain in his house. No acid fumigation is less injurious generally, yinegar ex-
cepted, to the lungs or fomiture, and its great efficiency marks it out as the most desirable,
alUiough much kdd aside in modem times. The amount arising from burning coal
most haye a great effect in disinfecting the putrid air of our streets, and rendering
coal-burning towns in some respects less unpleasant; this is one of the advantages
which that substance brings along with it, besides, it must be confessed, greater evils.
It is carious that this compound of sulphur should be one of the most efficient agents
in destroying sulphuretted hydrogen, another compound of Sulphur. Sulphurous acid
preyents decomposition, and also preserves the yaluable principle of a manure, so that
it belongs partly to the class of disinfectants, and partly to antiseptics.
The peciiliar actions of sulphurous acid and kreasote have been united in that called
** McDougall's Disinfecting Powder." Since in towns and farms, when disinfectants
are used, it is desirable not to use liquids, these two haye been united into a powder,
which assists also in removing moisture, as water is often a great cause of discomfort
and disease in stables and cowhouses. When they are used in this manner the acids
are united with lime and magnesia. When the floors of stables are sanded with the
powder, it becomes mixed with the manure, which does not lose ammonia, and is found
afterwards much more valuable for land. The cattle are also freed from a great
Vol. 11. D
34 DISINFECTANT.
amount of illness, because the air of the stable is purified. When fieoes of anj kiod
cannot be at once removed by vater, as by the water-closet system, the use of this is
invaluable ; but it is well to know that the instant removal of impurity by water is
generally best for houses, however difficult the after problem may be when &e river is
polluted. In stables and cowhouses this is not the case, and it is then that a disinfecting
powder becomes so valuable, although it is true that so many towns are unfortunately
so badly supplied with water-closets that disinfectants are still much wanted for the
middens.
The inventors have proposed to disinfect sewers, as well as sewage, by the nine
substances ; not, howeyer, m the state of a powder. They apply the acids to the
sewage water in the sewers themselves, and so cause the impure water to pass disin-
fected through the town ; by this means the towns and sewers are purified together.
When the sewage water is taken out of the town it can be dealt with either by preci-
pitation or otherwise. As it will cease to be a nuisance, covered passages for it will
not require to be made.
Lime is used for precipitating sewage water, and acts as a disinfectant as far as the
removal of the precipitate extends, and also by absorbing sulphuretted hydrogen,
which, however, it allows again to pass off gradually. The other substances proposed
for sewers have chiefly relation to the precipitation, and do not so readily come under
this article. Charcoal has been mentioned ; alum has been proposed, and it cer-
tiunly does act as a disinfectant and precipitant None of these substances have been
tried on a great scale excepting lime. An account of the Leicester experiment by lime
will come under the article Sewage.
Absence of air is an antiseptic of great value. The process of preserving meat,
called Appert's process, is by putting it in tin vessels with water, boiling off a good
deal of steam, to drive out the air, and then closing the aperture with solder.
Schroeder and De Dusch prevented putrefaction for months by allowing no air to
approach the meat without passing through cotton ; so also veils are found to be a
protection against some miasmas. Salts, or compounds of acids with bases, are
raluable antiseptics ; some of them are also disinfectants, that is, they remove the
state of putrefaction after it has begun. An antiseptic prevents it, but does not neces-
sarily remove it Common salt is well known as a preserver of flesh ; nitrate of
potash, or saltpetre, is a still more powerful one. Some of these salts act in a manner
not noticed when treating of the preceding substances, viz. by removing the water.
Meat, treated with these salts, gives out its moisture, and a strong solution of
brine is formed. Chloride of calcium prevents, to some extent, the putrefaction of
wood. Alum, or the sulphate of alumina, is not a very efficient preserver ; bat
chloride of aluminum seems to have been foxmd more valuable. It is sometimes
injected into animals by the carotid artery and jugular vein. Meat, usually keeps a
fortnight : if well packed, cleaned, and washed with a solution of chloride of alu-
minum, it will keep three months.
But in reality the salts of the heavier metals are of more activity as disinfectants.
It has been supposed that their efficiency arose from their inclination to unite with
sulphur and phosphorus, and there is no doubt that this is one of their valuable
properties, by which they are capable of removing a large portion of the impure
smell of bodies ; but they have also an inclination to combine with organic substances,
and by this means they prevent them from undergoing the changes to which they are
most prone. The actual relatiye value of solutions it is not easy to tell. Most expe->
riments have been made on solutions not sufficientiy definite in quantity. Salts of
mercury have been found highly antiseptic. Such a salt is used for preserving wood ;
the process is known as that of Kyan's, or kyanising. A solution of corrosive subli-
mate, containing about 1^ per cent of the salt, is pressed into the wood either by a
forcing pump or by means of a vacuum. The albumen is the substance most apt to
go into putrefaction, and when in that condition it conveys the action to the wood. It
is no doubt by its action on the albumen that the mercury chiefly acts. Thin pieces of
pine wood, saturated for four weeks in a solution of 1 to 25 water, with the following
salts, were found, after two years, to be preserved in this order : — 1. Wood alone,
brown and crumbling. 2. Alum, like No. 1. 3. Sulphate of manganese, like 1.
4. Chloride of zinc, like 1. 5. Nitrate of lead, somewhat firmer. 6. Sulphate of
copper, less brown, firm. 7. Corrosive sublimate, reddish yellow and still firmer.
In an experiment, in which linen was buried with similar salts, the linen was quite
consumed, even the specimen with corrosive sublimate. Other experiments showed
salts of copper and mercury to protect best— Gmdin,
Nevertheless, all these metallic salts are found true preservers under other coiidi«
tions. Chloride of manganese, a substance frequently thrown away, may be nsed, as
Gay-Lussac and Mr. Young have shown, with great advantage, and Mr. Boucherie has
shown the value of the acetate of iron. Mr. Boucherie's process is very peculiar.
DISTILLATION.
85
He feeds the tree, -when IWing, with the acetate of iron, by ponring it into a trough
dog aroond Uie root The tree, when cut down, has its pores filled with the salt, and
the albumen in the sap is preyented from decomposing. For preservation of yegetable
and animal substances, sec FnTB£PAcnoN, PaETBNTioN of.
The chloride of zinc of Sir William Burnett is also a yalnable disinfectant, and has
more power than it would seem to possess from the experiments quoted above.
Wood, cords, and canvass have been preserved bj it under water for many years. It
has the advantage also of being so soluble as to take up less room than most other
salts, although liquids generally are inconvenient as disinfectants in many places.
Nitrate of lead is a disinfectant of a similar kind ; it lays hold of sulphur, and the
base unites with organic compounds. All these metals are too expensive for seneral
use, and can only be applied to the preservation of valuable materials. Even iron is
much too dear to be used as a disinfectant for materials to be thrown on the fields
as manure. All are apt to be very acid, a state to be avoided in a disinfectant,
unless when it is applied to substances In a very dilute state, or in an active pntrid
state, and giving out ammonia. — R. A.S.
See also Sanitary Askanoehskts.
DISTILLATION. Distillation consists in the conversion of any substance into
vapour, in a vessel so arranged that the vapours are condensed again and collected to
a vessel apart.
The word is derived from the Latin dis and stillo, I drop, meaning originally to
drop or fail in drops, and is very applicable to the process, since the condensation
generally takes place dropwise.
It is distinguished from gubUmatkm by the confinement of the latter term to cases
of distillation in which the product is solid, or, in fact, where a solid is vaporiKd and
condensed without visible liquefaction.
The operation may simply consist in raising the temperatore of a mixture suffi-
ciently to evaporate the volatile ingredients \ or it may mvoive the decomposition of
the substance heated, and the condensation of the products of decomposition, when it
is termed deatructive dutiUation ; in most cases of destructive distillation the bodies
operated upon are so/iV, and the products liquid or gaseous ; it is then called dty dia-
tWatiaiu
In consequence of tbe diversity of temperatures at which various bodies pass into
vapour, and also according to the scale on which the (^ration has to be carried out,
an almost endless variety of apparatus may be employed.
Whatever be the variety of form, it consists essentially of three parts,— the retort
or MtULt the etmdenser, and the receiver.
On the tmatt ecale^ in the chemical laboratory^ distillation is performed in the simplest,
way by means of tbe common glass retort a, and receiver 6, as in^. 651. The great
651
652
advantages of the glass retort are that it admits of constant observation of the mate-
rials within, that it is acted upon or injured by but few substances, and may be cleaned
generally with facility. Its great disadvantage is its brittleness.
The retort may be either simple, as mfig. 652, or tubulated, as in >^. 651 (a).
Retorts should generalljr be chosen sufiKsiently convex in all parts, the degree of
curvature of one part passing gradually into that of the neighbouring portions, as is
d2
36 DISTILLATION.
repre«eDted in the figure ; the part to be heated Bhonld, moreorer, be u oniform in
point of thickneu u possible. The inbtilaled retort ia more liable to crack than the
plain one, od account of Ihe neceesorilj greater Ihicknen of the glua in the neigh-
bourhood of the tubnlHture ; nevenheleu it ii very convenient on account of the
faciliiy which it offen for the introdaction of the materiaU.
In charging retOTl* if plain, a fnnnel with a long stent ihonld be emplojedito avoid
soiling the oeck vlth the liquid to be diitilled : when a solid hat to be introdnecd it
ii preferable lo emplo j a tubulated retort ; and if a powdered lolid ii to be mixed with
a fluid it i> prefenble to introduce tbe fluid first.
Heat ma}- be applied to Ihe retort Hither by the argud gas flame, as injt;. 651, or
H water, oil. or sand-bath maj' be employed.
In distilling Tarioui subataoces, t. g., sulphuric acid, great inconvenience is expe-
rienced, and even danger incurred, hy the phenomenon termed "bumping." Thia
coneisls in the aecumuUlion of large babbles of vapour at the bottom of Ibe liquid,
which bursting cause a forcible expulsion of the liquid ftota tbe retort. It is pre-
vented by the iulroduclion of a few angular fragments of solid matter of soch a nature
as Dot to be acted upon by the liquid which is to be distilled. Nothing answer* tbi*
purpose better than a piece of platinum foil cut into a ft'ioge, or even a coil of plati-
num wire introduced into the cold liquid before Ihe distillation is commenced. Even
with (his precaution the distillation of sulpbaric acid, which it is often desirable to
perform for the purpose of its purification, is not unattended with dlfEJcnlty and
Dr. Mobr suggests the following method*: — A glass retort of ahont two ponnds
capacity, i> placed od a cylinder of sheet iron ia tbe Ceotre of a gmill iron furnace,
while its neck protrudes through ao opening in tbe side of the furnace (.ffji.GSS). Ignited
charcoal is placed round the cyliuder, without being allowed to come in contact with
the glass, and a current of hoi air is thus Diade to play on all parts of the retort
excepting the bottom, which is protected by its support There is a valve in the fine
of the furnace for regulating the draaght,and three small doors in Ihe cupola or bead,
for supplying fresh fuel on every side, and for observing the progren of tbe distil-
Instead of the sheet Iron cyliDdcr a hessian crucible may be employed, and this, if
requisire, elevated by phicing it on a brick. If the vapour he very readily condensed.
Dotliingmoreis necesssry tbanio bsert the extremity of tbe retort into a g^as* receiTet
asinj^. 651.
If a more efficient condensing arrangement be reqaislie, nothing iamore convenient
for use on the small scale than a Liebig's condenser, shown in ,fig. 654. It conaiatt
simply of a long glan lube into which Ihe neck of the retort is fitted, and the opposite
extremity of which passes into the mouth of the receiver ; round tbis lube is fitted
another either of glass or metal, and between tbe two a current of water it made to
flow, enlering at a and passing oat at ft. The temjieratore of this water may be
lowered to any required degree by putting ice into the reservoir e, oi by disulving
salts in it. (See FaEsztNo. }
Even on the small scale it Is sometimes necessary to employ distillatory sppantiia
constructed of other materials besides glass.
■ MotiT (Dit RedwDsd't Prwtiul PbvmWT.
DISTILLATION.
37
Euthenwire retort* are now eoiulrneted of very Mmvenieiit lues ind ihapea.
There la one ktod — vhich ii very aaefal when it is required to pui a gu into the
retort at the nine time that the distillaCioD ii going on, u in the preparation of
chloride of akunmimn, &c which haaatnbe paniag down into it alio made of
eartbeovare, ai iafig. 6SS. The eloKit are of Wedgevood ware, bnt a common cla]'
iMon maj' be made impenaeable to gatei, b^ waihing the nirface with a loliitiDn of
borsi, then carefDlly drying and heating them,
Betorta, or Saska witb bent tube*, which kkt in thnt {fig. 6S6), of copper, are
S99
65fi
employed when it ii reqniaile lo prodnce high temperBtorei, u for the preparation of
bensole tiram benzoic acid and baryta, or in malting marsh gu from an acetate, &c.
In diatiUing hydroflaoric acid the whole apparatua ahontd be conatmeted in leadj
the receirer conaiiting of a U -shaped titbe of lead, which ia fitted with leaden atoppers
so as lo aerve for keeping the ncld when prepared ; or a receiver of gutta percha may
be employed with a stopper ofthe same mitcriat. (.Fig. 657.)
For many purposea in the laboratory ai, for instance, the preparation of oxygen by
heating binoxide of manganeae, — in the maau&clare of potassiom, &c. See. , where
bigh lemperatnrea are repaired, the iron bottles in whidi mercury is imported from
657
69B
W'
Spain may be employed, a common gnn-barrel being screwed into them to act aa a
delivery tabe or condenser, (Fijr. 658.)
On a large scale an almost cndiesa variety of atills have been and are still employed,
which are constructed of diOerent mateinala.
The common ■'stitl" coniists of a retort or still pmpcr, in which the subslance is
heated; and a condenser commonly called a "wonn"on accnnnt of its having fre-
qaenll; a spiral shape. The retort or still ia generally made in two parts ; the pan
or cop/KT, which is the part to which heat is applied, and ia commonly set in a furnace
of bricksork, and the " htad" which is generally removed after each operation, and
nfixed and luted npon the pan when igun osed. The condenser or worm is com-
monly placed in a tube or other veaael trf water, (See/ij, 661.)
The Btill may be either constructed of earthenware, or, as is very conmionly the
case, of copper, either plun or electro-plated with silver, according to circDmstances i
lees freqoeDtly platinum is employed.
The still is either healed by an opei^ fire, as in Jig. 656, or, as is aow vety conimoiity
38 DISTILLATION.
the CMC, by itrani. The >tiU-paD (jfj. 659) ii Buirounded by an outer copper jtelcet,
and steam i« Admitted betveea them fhim a ateam boiler under any reqnired pres-
lure. Id Ibis na; the lenperatara may be regulated vith the greatest nicety.
Various adaptations for heating by steam hare been appropristelj arranged in a
Tcry oonTtnieBt form by Mr. Coffey, of Bunbill Row, Finsbnry, in bis sii-CBlted
EscuUpinD Still. It is in l^f^t a veritable mullum iaparvo, being intended to aSbrd to
the pharmaceutical chemist the means of conducting the processes of ebullition, distilla-
tion, eTaporalion, desiccation, &c., on the small scale, by the heat of a gns-fBrnace.
The foUoving sat (Jig. 660) represents thia apparatus.
660
DISTILLATION. 39
valve for iliattiBg off the Meun fivm i, -when it puaet throDf^ the tabe m, other-
wue it voold psai tbrongb l. utd comma aicate heat to the diying-cloiet o o, and
from thsDce to the oondeaacr t t. o it * Mcond etaporalin|; pan OTer the drjtng-
cloairt. Another ■mnguneiil for dittilling by Meam ia ihown in Jig. 061.
Sometime* alto dinillatioD is effected b; pawing hot (team through a ironn con-
luned KilAn the still, imtead of or in addilioD to, the application of beat from
The vonn or eondenaer i« frcqnentlj conatmeted of earthenware, and ut in an
earthenwaiv veMel, theie are Ttirj conienient when the operatiou is not to be con-
docted on B very targe Kale, and only at a moderate lemperatore. They are now lo
be obtained of alt mana&etaren of itone-wara artidca. More commonly the worm
il of eopper, tin, or copper lined with lilver, and in aome rare case* where the liquid*
lo b« dulilled act epon both copper and lilTcr, of platinum. {Fig. flea.)
661
F^
venel of a pritmatic form which ocoopie* bat little tpace : the water employed for
coDdennuioTt enter* nt the bottom and pnues oat at the (op.
Gadda'i ecndtiuer is represented in fiq. 664. Il consisli of two conical veuvls of
metal, of nncqoal aiie the smaller being fixed within the other, and (he apace between
40 DISTILLATION.
them closed at the bottom. These are placed io a tub filled with cold water, which
cornea in eoDlact with the ioner and outer Bur&ces of the codm, wbiJe the (para
between i» ocenpied b; the vapour to be condensed. Thia condenser it lubject lo [be
otgection which appliei to the common worm, that it ciuiQOt be eaiiJy and efficienil;
To obviate tbii, Profeitor Mit*cherlicb hM propoied a very simple modification in
it« foriD, in which ihe inner cone is rooTable, lo that, when talien out, the intervening
space belween itaud the oaler cone cin be cleaned, and then the inner eona reflaeed
previooily to commencing an operation.
DUtdlalim of SpirilM. — In the manaractore of ardail $pirilt, the tiedholic liquor
obtained bj fermentation of a saccharine soiulion is submitted to distillation i the
alcohol bein^ more volatile tlinn the wsler pitsses »ier first, but invariablj a consider-
able proportion of water is evaporated and condensed with the alcohoL To sepaMe
this water to the required extent it is necessary either to submit the product to redis-
tillation, or to contrive an apparatus such that the product of this fint diatillation ia
relorned to the still until a spirit of the required strength is obtaioed.
One oftbeearlieBt and simplest coutrivances for efiecting the latter object ii the sliU
invented bj Dorn, which ii employed up to the present lime in Germany (Jig. GGS).
A is the aiill, heated by Ibe direct action of the fire ; B the head, from which r txaieji
vapour to a small refrigerator, for the purpose of testing the slrcngth of the distillate ';
B ia an ordinary condenser containing worm, &c The intcrm^iate copper veoel
answers mo purposes; the upper part c forming a heater for the wash, while the lover
compartment b acts as a rectifier. The healer c, whan filled np to the level of the
cook B, contains the exact measDrc of wish fbr charging Ihe still ; the eonients can
be constantly agitated by the rouscr i. The still and healer being both charged, Ihe
vapourwill at first be completely condensed in passing through the worm g, andflov-
iog into D will close Ihe npcrlure. When the contents of c become bo hot thst no
more condensation occurs, Ihe vapour will escape by hubblinR through the liqoid in n,
which latter rapidly becomes healed to Ihe boiJing point, imd evolves vapours richer
in alcohol, which in their turn are conden<ied in e.
In thif mnoner, by one operalion, spirit containing about 60 per cent, of alcohol is
obtsincd.
or the recent improvements on Bom's still two only need be described :— CoH'eT■^
which has in a great measure replaced ail othen in thiscountry.and Dennne's, wbich
is extensively employed in France.
Coffey's still fnr surpasses any of those before described. It was patented in I8SS,
and has proved mo«l valuable to the distiller, since it yields the strongest spirit thil
can be obtained on the large scale.
Its objects are twofold:— lat, to economise Ihe heat, as much as pooible, by ex-
posing the liquid to a very extended healed surface ; Sud, to cause Uie evspoiation
of the alcohol from the wash by passing a current of steam through it
The wash is pumped from the " wash charger " into the worm tube, which passes
{torn top to bottom of the rectifier. In circulating (hrongli ihis tnbe its temperalore
is raised lo a cenain extent Arrived at tiie Ust convolution of the tube in the
rectifier the wuh passes by Ihe tube mm in at the top of the "analyser." ItfnIliSDd
DISTILLATION.
42 DISTILLATION.
oollecta apon die top shelf antil this overflowt, wheooe it falls on t« tlie leeond shelf
ftnd so 00 to the bottom. All the while sleom is passed up rrom the steam boiler
through fine botes in tlic ebelves, and through Tslves opeoing upwards. As the wuh
gniduBllj descends in the aaaljser it becomea npidly weaker, panlj fVnm conden-
sation of the steam which is pa^ed into it, and partly from loss of alcohol, either
evaporated or expelled bv the steam ; till, when it airiTes at the bottoin, it has parted
with the last traces of spirit. At the same time the vapour, a* it rises through each
shelf of the analyser, becomes con^naoasly richer in alcohol, and contains less and
leu water in consequence of its condensation ; it then passes from the top of the
analyser in at the bottom of the lower compartmeat of the rectifier. Here it ascends
in a similar way, babbling through the descending wash, nntil it arrives at r, above
which it merely circulates round the earlier windings of the wash pipe, the low tern*
peraturc of which condenses the spirit, which, collecting on the shelf at r, flow* off
by the tube into the finished spirit condenier.
In order Blill ftirther to economise heat, the water for supplying the boiler is nade
to pass through a lon^ coil of pipe, immersed in boiling hot spent wash, bj which
means its temperature is raised before it enters the boiler. In f^t the saving of fuel
by the employment of this still is so great, that only about three-fourths of the
quantity is consumed that would he requisite for distilling an^ given quantity of
alcohol in the ordinary still ; and Dr. Muspratt estimates that io this way a saving
will be effected throughout the kingdom of no less than 140,000 tons of coal per
Very few persons have any idea of the enormoos Kse of some of the distilleries.
One of Mr. Coffey's stills at Inverkeithing works off 3000 gallons of wash per hour,
ftod one, more recently erected at Leilh, upwards of 3000 gallons.
Deromt't ttill is very similar, in the prmciple of its action, to Coffey'a, differing in
eg7 fact only in the mechanical
details by means of wbicb the
result is obtained.
It conusts of two stills, A.
and B,jSp. 667. The mlitnre
of steam and alcohol vapour
from A passes into the liquid
in B, which it raises to the
boiling point The vaponrs
from B rise through the <iul3-
latoiy column c, and o (the
rectificatory column) ; bence
they traverse the coila of
tubing in e (the conrfeiutr and
vine heater), and the alcohol
is finally condensed by tra-
versing the worm in r (the
Ttfrigrrator), whence it is deli-
vered at z. At the same time
a steady current of the ori-
ginal alcoholic liquor is ad-
mitted from the reservoir H,
into the exterior portion of the
condenser f, by means of the
tap, the flow from whicb is
regulated by the ball cock $.
Whilst condensing the spirit
in the worm the waab has its
temperature raised, especially
inthenpperpBrt,andihenceit
ascends by the tube h into the
heater e, by the small ori£ces
k k, fig. GG8, where it is still
further heated by the current
. of healed alcohol which has
t- risen into the worm ttom the
stills, whilst at the same time
ansisling in the condensation
of the spirit After perform-
ing its office of condensauon,
andwEen nearly nt the boiling point, the alcoholic liquor pnsscs out by the tube^ and
DISTILLATION.
progTCM into tbe atill b, ud jet permit ^°^
ihe ucent of tlie itewn. In thu dis-
tUlatoTj colDmn (c, jig. STO) it meeta
Ihe ite&m riaog from the still b. The
greater p&rt of itt alcohol is expelled,
wtucfa, traTening die aeries of con-
deosen before described, is allinuiletj
liqaefied and collected at z; but, to
complete Ihe rectificatioo, it descends
into the still B, and, irben above a
certain level (m n), into l, which stills
being heated by a fnmace beneath, the
final expulsion of alcohol is Mcom-
plished, and the spent liqaor run tS
The details of the eonstniction <A
the apparatus employed in the dis-
lillation of spirits have been here given,
since this process is perhaps one of the
Djott important of the kind ; bnt va-
riooa modifications are employed in
the distillation of other Iir)uids.
In some cases, Dnasually eSeCloal
condensing amngenieiils are required,
as in the manufacture of Etbeh, Chu>-
soroKM, BiBULFBiDE or Caibom, and
BiCHLOBiDE or Cakbon.
la others higher temperatures are
necessary, as in the distillation of sul-
phuric acid.
When the liquids to be distilled are acid, or otherwise corrosive, great care has to
be taken especially that the worm or other condenser is of a material not acted upon
by the scid. See Acetic Acid, and Sulphdbic Agii\
The term distillation is sometimes applied to cases of the volatilisation and subse-
quent condensation of the metals either in their preparation or purification.
In cases like mercnrj, potassium, and sodium, where they are condensed in the
liquid state, or fisibly pass through this state before volatihsation, this term is quite
^ipropriate i but where the fusing and vaporising points nearly coincide, as in the
ease of arsenic, Ihe term aublimation would be more suitable.
Nevertheless it is difficult to draw a precise line of demarcation l>etweeo the two
terms \ for in the cases of zinc cadmium, &c., the metals being melted before vola-
tilisation, and condensed likewise in the liquid state, the term is certainly corrccl.
For the details of construction of the distillatory apparatus we must refer to the
articles on these several mclnls.
Di^iilatio^ daceaum is a term improperly applied to certain eases of distiUalion
vbetv the vapour is dense, and may be oollected by descendiog through a tube which
44 DISTILLATION, DESTRUCTIVE.
has an opening in the top of the distillatory yessels, and descends through the body of
the vessel in which the operation of evaporation is going on, being collected below.
This is clearly merely due to the fact of the vapoar being even at a high tempera-
ture more dense than atmospheric air, and might be performed withany body fomung
a dense vapoar, such as mercury, iodine, zinc, &c.
It has, however, practically been confined to the English process of refining sine.
See Zinc.
The two most remarkable cases in which the process of destructive distillatioin is
carried out on a manu&cturin^ scale, are the dry distillation of wood, for the manu-
facture of wood charcoal, acetic acid, and pyrozilic spirit (which see); and of coal, for
the purpose of obtaining coal gas, and coke. This process will be found fully de-
scribed in the article on Coal-oas.
Distillation of Essential Oils or Essences, — The separation of volatile flavouring
oils fVom plants, &c, by distillation with water, will be fUUy treated under another
head. See Perfumest, Essences.
Fractional Distillation, — A process for the separation of volatile organic substances
(such as oUs) is very extensively employed in our naphtha works under this name.
If we have two volatile bodies together, but differing appreciably in their boiling
points, we find, on submitting them to distillation in a retort, through the tubulature
of which a thermometer is fixed, so that its bulb dips into the liquid, that the tem-
perature remains constant (or nearly so) at the point at which the more yolatile con-
stituent of the mixture boils, and the distillate consists chiefly of this more volatile
ingredient ; and only after nearly the whole of it has passed over, the temperature
rises to the point at which the less volatile body boils. Before this point has been
reached, the receiver is changed, and the second distillate collected apart. By sub-
mitting the flrst product to repeated redistillation, as long as ita boiling point remains
constant, the more volatile constituent of the mixture is ultimately obtained in a state
of absolute purity. See Naphtha.
This method may in fact be adopted when the mixture contains several bodies ;
and by changing the receiver with each distinct rise of temperature, and repeating
the process several times, a fractional separation of the constituents of the mixture may
be etfected.— H. M. W.
DISTILLATION, DESTRUCTIVE. Organic matters may be divided into two
groups, founded on their capability of withstanding high temperatures without under-
going molecular changes. Bodies that distil unchanged form the one, and those which
break up into new and simpler forms, the other. The manner in which heat acts
upon organic substances differs not only with the nature of the matters operated upon,
but also with the temperature employed. We shall study the subject under the
following heads : —
1. Apparatus for destructive distillation,
2. Destructive distillation of vegetable matters,
3. Destructive distillation of animal matters,
4. Destructive distillation of acids.
6, Destructive distillation of bases.
6. General rmarks.
1. Apparatus for destructive distillation. — Destructive distillation on a large scale is
most conveniently performed in the cast iron retorts used in gas works. Where quan-
tities of materials not exceeding fifteen or twenty pounds are to be operated on, for
the purpose of research, a more handy apparatus can be made fh>m one of the stout
cast iron pots sold at the iron wharves- They are semi-cylindrical, and have a broad
flange round the edge. The cover should be made to fit in the manner of a saucepan
lid. The aperture by which the products of distillation are to be carried away should
be of good size, and the^exit pipe must not rise too high above the top of the pot before
it turns down again. This is very essential in order to prevent the less volatile portion
of the distillate from condensing and falling back. The exit tube should conduct the
products to a receiver of considerable capacity, and of such a form as to enable the
solid and fluid portions of the distillate to be easily got at for the purpose of examin-
ation. From the last vessel another tube should conduct the more volatile products
to a ^ood worm supplied with an ample stream of cold water. If it be intended to
examme the gaseous substances yielded by the substances under examination, the exit
pipe of the worm must be connected with another apparatus, the nature of which
must depend on the class of bodies which are expected to come over. If the most
volatile portions are expected to be basic, it will be proper to allow them to stream
through one or more Woulfe's bottles half filled with dilute hydrochloric acid. Any
very volatile hydrocarbons of the C'H" family which escape may be arrested by
means of bromine water contained in another Woulfe's bottle. The pressure in the
Woulfe's bottles must be prevented from becoming too great, or the leakage between
DISTILLATION, DESTRUCTIVE. 45
the flange of tlie pot and its coyer will be yery considerable. The latbg may consist
of finely nfted Stourbridge clay, worked up with a little horse dung. A few heavy
weights should be placed on various parts of the lid of the pot, so as to keep it close,
and render the leakage as little as possible. For the destractiye distillation of small
quantities of substances, I have been accustomed for a long time to employ a small
still made from a glue pot, and having a copper head made to fit it The luting for
all temperatures not reaching above 700 may be a mixture of jths linseed and ^th
almond meal, made into a mass of the consistence of putty. For the apparatus em-
ployed in the destructive distillation of wood, coal, bones, &c, on the large scale, the
xarious articles in this work on the products obtained from those substances must be
coDBulted.
2. Deatruetive distillation of vegetable matters.»~-The principal vegetable matters which
are distilled on the large scale are wood and coaL We shall consider these separately.
Destrucdve distillation of wood, — The products obtained in the ordinary process of
working are acetic acid, wood spirit or methylic alcohol, acetone, pyrozanthine, xylite,
lignine, paraffine, kreosote. or phenic acid, oxyphenic acid, pittacal, several homologues
of benzole, with ammonia, and methylamine. There are also several other b^ies
of which Uie true nature is imperfectly known. The greater part of the above sub-
stances are fhlly described in separate articles in this work. See Acetic Acid, Pa-
RJLFFDIE, &C.
Peat appears to yield products almost identical with those from wood.
Destructive distillation ofcoaL — The number of substances yielded by the distillation
of coal is astonishing. It is very remarkable that the fluid hydrocarbons produced at
a low temperature are very different to those distilling when a more powerful heat is
employed. The principal fluid hydrocarbons produced by the distillation and subse-
quent rectification of ordinary gas tar are benzole and its homologues ; see Hydro-
CARBOKS. But if the distillate is procured at as low a temperature as possible, or
Boghead coal be employed, the naphtha is lighter, and the hydrocarbons which make
its chief bulk belong to other series. See Naphtha.
3. Destructive distillation of animal matters. — Bones are the principal animal sub-
stances distilled on the large scale. The naphthas which come over are excessively
foetid, and are very troublesome to render clean enough for use. The products con-
tained in bone oil will be described in the article Naphtha. Horn and wool have
recently been exammed with reference to the basic products yielded on distUlingthem
with potash. Horn under these circumstances yields ammonia and amylamine. Wool
I find to afford ammonia, pyrrol, butylamine, and amylamine. My experiments on
feathers, made some years ago, although not carried so far as those on wool, appear
to indicate a very similar decomposition.
The products yielded by animal matters, when distilled per se^ are very different
to those obtained when a powerful alkali is added previous to the application of
heat. If feathers or wool be distilled alone, a disgustingly foBtid gas is evolved
containing a large quantity of sulphur. Part of the sulphur is in the state of sulphide
of carbon. But if an alkali be added previous to the distillation, the sulphur is re-
tained, and the odour evolved, although powerful, is by no means offensive. During
the whole period of the distillation of ordinary organic matters containing nitrogen,
pyrrol is given off, and may be recognised by the reaction afforded with a slip of deal
wood dipped in hydrochloric acid. An interesting experiment, showing the formation
of pyrrol from animal matters, may at any time be made with a lock of hair, or the
feather of a quill. For this purpose the nitrogenous animal matter is to be placed at
the bottom of a test tube, and a little filtering paper is to be placed half way up the
tube, to prevent the water formed during the experiment from returning and frac-
turing the glass. The end of the tube is now to be cautiously heated with a spirit
lamp, and, as soon as a dark yellowish smoke is copiously evolved, a slip of deal pre-
viously moistened with concentrated hydrochloric acid is to be exposed to the vapour.
In a few seconds the wood will acquire a deep crimson colour. The fact of the pre-
sence of sulphur in wool, hair, or other albuminous compounds of that description,
may be made very evident to an audience by the following experiment Dissolve the
animal matter in very concentrated solution of potash in a silver or platinum basin,
with the aid of heat Evaporate to dryness, and raise the heat at the end to fuse the
potash and destroy most of the organic matters. When cold, dissolve in water, and
filter into a flask half full of distilled water. To the clear liquid add a little of Dr.
PlayiUr's nitroprusside of sodium ; a magnificent purple tint will be immediately pro-
duced, indicative of the presence of sulphur. A very small quantity of hair or flannel
will sufllee to yield the reaction.
The above remarks on destructive distillation apply principally to highly complex
bodies, the molecular constitution of which is either doubtful, as in the case of albu-
minoos substances, or totally unknown, as with coals and shales. The destructive
i
I
46 DISTILLATION, DESTRUCTIVE.
distillation of organic substances of comparatively simple constitntion, such as acids
and alkalies, sometimes yields products, the relation of which to the parent substance
can be clearly made out This holds more especially in the case of organic acids; the
bases too often yield such complex results, that the decomposition cannot be expressed
by an equation giying an account of all the products. We shall study a few cases
separately.
4. Deatructive distillation of acids. — The destructive distillation of acids takes place
in a totally different manner, according as we have a base present or the operation is
carried on withoat any addition. Many if distilled per se undergo a very simple re-
action, consisting in the elimination of carbonic acid, and the formation of a pyroacid.
But if an excess of base be present, the decomposition often results in the formation
of a ketone (see Acetone). We shall offer a few examples of these decompositions.
Gallic acid, heated to about 419° Fahr., is decomposed into pyrogallic and carbonic
acids, thus: —
C"H«0»« « C"H«0« + 2C0»
V
Gallic acid. Pyrogallic acid.
There are cases in which the action of heat upon organic acids results in the for-
mation of two substances, not produced simultaneously, but in two epochs or stages.
In reactions like this, the first effect is the removal of two equiyalents of carbonic
acid, and by submitting the resulting acid to heat again, two more are separated.
Under these circumstances, it is the second which is generally called the pyroacid. As
an example we will take meconic acid which breaks up in the manner seen in the
annexed equations.
C"H«0" =3 C*«H*0" + 2C0* C"HW« « C'»H*0« + 2C0«
Meconic acid. Comenic acid. Comenlc acid. Pyromeconlc acid.
It will be seen that the hydrogen remains unaffected. Perhaps the name pyroco-
menic acid would be preferable to pyromeconlc acid, inasmuch as it is derived fmn
comenic acid in the same manner as pyrogallic from gallic acid.
But pyroacids are not always derived from the parent acid by the mere elimination
of carbonic acid ; thus mucic acid, in passing into pyromucic acid, loses two equiyalents
of carbonic acid, and six equivalents of water, thus: —
C"H>K)'« - CWH^O* + 2C0« + 6HO
V
Mucic acid. Pyromucic acid.
It does not invariably happen that the destructiye distillation of acids perse results
in the formation of a pyroacid, the disruption is sometimes more profound, the products
being numerous and somewhat complex. Let us take as an illustration a case where all
the results can be reduced to an equation. Oxalic acid, when heated in a retort withoat
addition, yields water, oxide of carbon, carbonic and formic acids, in accordance with
the annexed equation : —
4(CK)«,H0) = 4C0« + 2CO + 2H0 + C«HO«,HO
Oxalic acid. Fomilc acid.
The admixture of sand, pulverised pumice stone, or any other inert substance in a
state of fine division, often remarkably assists in rendering the decomposition more
easy and definite. Thus, if pure sand be mixed with oxalic acid, the quantity of formic
acid is so increased, that the process is sometimes employed in the laboratory as a
means of affording a pure and tolerably strong acid.
We have said that the destructive distillation of acids proceeds in a very different
manner according as we operate upon the acid itself, or a salt of the acid. The dis-
tillation of the pure salt yields different products to those which are obtained when
the salt or dry acid is mixed with a large excess of a dry base (such as quicklime),
before the application of heat If, in the former mode of proceeding, two atoms of
the acid are decomposed, yielding a body containing (for four volumes of yapour, see
Formula) the elements of two atoms of carbonic acid and two of water less than the
parent acid, such body is called a ketone. Thus when two atoms of acetate of lime
are distilled, the products are one atom of acetone, and two of carbonic acid. Of
course the carbonic acid combines with the lime, thus : —
2(C*H«CaO*) « C'HHP + 2(CaO,CO«).
Acetate of lime. Acetone
If, however, the salt is not of a very low atomic weight, and the quantities operated
on are at all considerable, secondary products are formed, as in the dry distillation of
DIVmiVL
47
outyrate of lime, wheD» if the substance is not in very small quantity, carbon is deposited,
and a certain qaantity of batyral (C'H'O^) is formed, and probably other substances.
As an illustration of the decomposition undergone irhen acids are distilled with a
^reat excess of dry base, we shall select that of benzoic acid, which under the circum-
stances alluded to yields benzole and carbonate of the base.
C"H«0* - C«H« + 2 (CO«)
Bensoic add. Beniole.
5. Destructive dutiBaticn o^beues, — It has been found that the organic bases undergo
a much simpler and more direct decomposition when subjected to destructiTC distiUa-
tion in presence of alkalies than when they are exposed to heat without admixture.
There are two bodies almost invariably found among the resulting products, namely
ammonia and pyrroL In this respect, therefore, the organic alkalies behave like
other nitrogenised animal and vegetable products. The decomposition is almost
always rather complex, and it is very rare that the products are sufficiently definite
to be arranged in the form of an equation. The most common substances found, are
the alcohol bases, and these are almost invariably of low atomic weight One great
difficulty connected with researches on this sulject, is owing to the fact of its teing
seldom that the products are in sufficient quantity to enable a thorough knowledge of
the molecuhu* constitution to be arrived at Unfortunately this information is much
-wanted in consequence of the numerous cases of isomerism to be met with among the
alcohol baaeSb See FoaHinLB, Chekical. Thus it is difficult, when working on
Tery small quantities, to distinguish between bimetlfylamine and ethylamine, both of
which have the formuhi OH'N.
It is remarkable that thero is a great similarity between the products of the des«
tmctive distillation of some of the most unlike nitrogenous substances. This is con-
spicuously seen in the case of bones, or rather the gelatinous tissues of bones, shale
and ooal naphthas, and cinchonine. An inspection of the following table, compiled
from a paper (by the writer of this article), ** On some of tEe Basic Constituents of
Coal Naphtha," will render this evident
Gclatlnoas TiHoet.
Shale Naphtha.
Coat Naphtha.
Cinchonine.
Pyrrol.
Pyridine.
Picoline.
PyrroL
pyridine.
Picoline.
PyrroL
Pyridine.
Picoline.
Pyrrol.
Pyridine.
Picoline.
Lutidine.
Lutidine.
Lutidine.
Lutidine.
Collidine.
Collidine.
Collidine.
Collidine.
.
Parvoline.
-
-
Chinoline.
Chinoline,
Aniline.
• «
Lepidine.
Cryptidine.
Aniline.
lepidine.
It is very possible that some of the above bases, having the same fonnulie, but de-
rived from different sources, will, in course of time, prove to be merely isomepc, sod
not absolutely identicaL The author of this article has quite recently found that the
chinoline of coal tar is certainly not identical with that from cinchonine. The base
from the latter source yields a magnificent and fiist blue dye upon silk, when treated
by a process which gives no reaction if the coal base be substituted. It is unfortunate
that the reaction is with the latter instead of the former, as it would have added one
more to the list of gorgeous dyeing materials yielded by coal tar.
6. General Remarka. — The tendency of numerous researches, made during the last
few years, has been to show that there is no organic substance, capable of resisting
high tempeiatares, which may not be found to exist among products of destructive
distillation. By varying the nature of the substance to be distilled, and also the cir-
cumstances under which the operation is conducted, we can obtain an almost infinite
variety of products. Acids, bases, and neutral substances, solid, liquid, and fluid
hydrocarbons, organic positive, negative, and derived radicals, organo-metallic bodies,
— all may be produced by the action of high temperatures on more or less compli-
cated bodies. Much has already been done, but the facts at present accumulated
relate merely to the superficial and more salient substances. On penetrating further
below the surface fiir more valuable and interesting facts will come to light — C.G.W.
DIYIDIYI, or Libi Davi^ is the pod of a leguminous shrub, which is an indigenous
production of Jamaica, and some parts of South America. Mr. Rootsey obtained a
mean produce of 6*625 grs. of leather from 60 grs. of dividivi, while the same quantity
of the best Aleppo galls yielded only a mean produce of 4*625. It appears too
from Sir Humphry Davy's estimate, that 60 grs. of dividivi contain 3*0476 grs. ot*
5-079 per cent of tannin, and 60 grs. of galls, 2*12704 gniia, or 3*450 per cent
Tons.
Carayoa
- 229
New Granada
- 2,617
Venezuela -
- 372
Other parts -
35
26,554
3,925
369
48 DIVING-BELL.
Sixty gn, of oak bark yielded only 1'75 grains of leather; whence it follows that it
contains but 0'805 of a grain of tannin to the drachm, or not more than 1 '34166.
It has been tried as a dye instead of galls or sumach, but its use for this purpose is
almost entirely abandoned. See Leather.
Diyidivi imported in 1857 : —
computed real value, 2,4 1 6
»» »»
»» >»
3,153 £33,264
DIVING BELL. As it is frequently desirable to raise objects from the bottom of
the sea or rivers, and to lay the foundation of piers and similar structures, some con-
trivance was desired to enable man to descend below the water, and to sustain himself
while there. The first method adopted was the very simple one of letting down a
heavily weighted bell vertically into the water. As the bell descended, the air got
overpressed, and the water rose in the bell, but never to the top, and within that
space the man was sustained for some time. The air, however, was vitiated by the
processes of respiration, and the man had to be drawn up. It is curious to find that
as early as 1693 a ver^ complete system of diving without a bell was devised, as the
following quotation will show.
A.D. 1693. ^William and Blary, by the Grace, &c &c. Whereas John Stapleton,
gentleman, hath by his great stddy and expence invented a new and extrsordinary
engine of copper, iron, or other mettal, with glasses for light joints, and so contrived as
to permit a person enclosed to move and walk freely with under water, and yet so
closely covered over with leather as sufficiently to defend him fh>m all the jumpes of it.
Also invented a way to force air into any depth of water, whereby the person in the
aforesaid engine may be supplied with a continual current of fresh aire, which not
only serves him for respiracon, but may alsoe be ute/ul far continuing a lamp burning^
which he may carry about with him in hie hand, • • • Likewise a way to
make the same again serviceable for respiracon, and by continually repeating the
operacon, a man mav remain a long time under water, in either of the said engines,
without any other air than the sayd engines do contayne, whereby he shall be pre-
served from suffocation if any extraordinary accident should interrupt the current of
fresh air afore menc5ned." — Letters Patent Rolls Chapel Edited by Bennet Woodcro/t
The defects were many in this apparatus, and Dr. Halley invented a bell, the object
of which was to remedy them.
Dr. Halley's bell was of wood coated with lead, and having strong glass windows
above, to allow the passage of light to the diver. In order to supply air, a barrel was
taken with an open hole m the bottom, and a weighted hose hanging by, and fitting
into a hole at the top. From this barrel the air of the bell was supplied as frequently
as it became vitiated, the barrels of air being sent down from above. Spalding im-
proved upon Halley's bell, and again Friewald made some improvements on Spalding's,
but in principle these bells were all alike. The modem bells are usually large and strong
iron bells, with windows in the upper part By means of an air pump, placed on the sar-
&ce, air is sent down to the divers in the bell, and the vitiated air is as regularly
removed from the bell bv other tubes through which it escapes. These diving bells
are lowered by means ot cranes, and are moved about in the water by those above,
signals being given by the men below. The difficulty of moving this machine, renden
it still inconvenient, and recent attempts have been made to obviate this, by the con-
struction of a diving bell upon principles entirely different. This new diving bell,
to which the name of The NAUTiLns has been applied, has proved so useful in the
construction of some parts of the Victoria Docks, and some works on the Seine, that m
full description of it is appended.
The nautilus machine is entirely independent of 6usi)ension ; its movements are
entirely dependent on the will of those within it, and without reference to those who
may be stationed without ; it possesses the power of lifting large weights, per m, and
at the same time is perfectly safe, by common care in its operations. This latter ia
the greatest desideratum of all. These advantages must strike all as combining
those requisites of success which have been always wanting in the present known
means for constructing works under water.
The form of the machine is not arbitrary, but depends entirely on the nature of
the work to be performed, adapting itself to the various circumstances attending any
given position. By reference to the annexed figures it will be perceived that when at
rest, being entirely enclosed, its displacement of water being greater than its own weight,
it must fioat to the surface (see Jig. 671). Entering through a man-hole at the top
(which is closed either from the inside or outside), yon descend into the interior of the
DIVING BELL. 49
mmchiBV, portloiu of whieb »re willed off on cither nde, formiDg chkinbera ; theM
chambera are cooneeud at or near tb« bolKun of a pipe a a, vhidi opeu by ■
cock i, oalwnrdi to the extensl (urrouDdIng water. Aa openiog ia the bottom of
the machine of variable dimetuions ia closed b; a door or doors luaceptible of being
opentd or closed at pleaMin^ The chamben w w, are likewise coDoected U top hj
a smaller pipe ee, which opeiu tbrongh the top of the machine, and to which opening
is affised a flexible pipe, with coits of wire spirally enclosed. Branches on this
Utter pipe T, allow also commnnicBtlon with the larger or working chamber.
At the surface of [be water placed on a float or vessel for the pnrpase, is a receiver
of variable dimensions, to which is attached at one end a hoUow dram or reel, to the
barrel of which is affixed the other end of the flexible pipe a, leading to the top of
the naatilns. At the other end of, and In connection with the receiver, is a powerful
air -condensing pump. This combination represents the nancUus as adapted to
engineering work.
At to the wndia operaitdi: — The operator with his ssiislanta enters the maehlaa
through the top, which is then closed. To dcKend, the water-cock b ii opened, and
the external water flows into the chambers w w ; at the same time a cock, on a pipe
Vol. IL E
€0
DIVING BELL.
opening from the chambers outwards, is opened, in order that, the mr escaping^, an
nntnterrapted flow of water may take place into the chambers. The weight of water
entering the chambers caoses a destraction of the buoyancy of the machine, and
the nautilus gradually sinks. As soon as it is fairly under water, in order that
the descent may be quiet and without shock, the water-cock &, is closed. The re-
ceiver at the surface being previously chMiged by the air pump to a density scnne-
what greater than that of the water at the depth proposed to attfun, one of the
branch-cocks on the pipe c r, connecting the chambers at top, is opened, and the air
rushes into the working chamber, gradually condensing until a density equal to the
density of the water without is attained; this is indicated by proper air and water
gauges. These gauges marking equal points, showing the equilibrinm of forces
without and within, the cover to the bottom z is removed or raised, and commonica-
tion is made with the under water surface, on which the nautilus is resting. In order
to move about in localities where tides or currents do not affect operations, it is only
necessary for the workman to step out of the bottom of the nautilus, and placing the
hands against its sides, the operator may move it (by pushing) in any direction.
Where currents or tides, however, have sway, it becomes necessary to depend upon
fixed points from which movements may be made in any direction. This is accomplished
by placing, in the bottom of the nautilus, stuffing boxes of peculiar construction (m m,
fig. 672), through which cables may pass over pulleys to the external sides, thence
up through tubes (to prevent their being worn), to and over oscillating or swinging
pulleys, placed in the plane of the centre of gravity of the nautilus, and thence to
the points of affixment respectively (Jig. 673). The olgect to be gained by having
673
^^^s^-^.^^--^
the swinging pulleys in the plane of the centre of gravity of the masB, is to hold the
machine steady and to prevent oscillation. Within the machine, and directly over the
above stuffing boxes, are windlasses for winding in the cables. By working these
windlasses movement may be effected, and of course the number of these cables will
depend on the variable character of the situation to be occupied. Having thus
secured the means of descending, communicating with the bottom, and of movement,
the next point is to ascend. Weight of water has caused a destruction of buoyancy
at first, and consequent sinking ; if then any portion of this water is removed, an
upward effort will at once be exerted exactly proportionate to the weight of water
thrown off.^ The sir in the receiver at the surface being constantly maintained at a
higher density than that of the water below, if we open the water cock on the top
pipe, c, c, throwing the condensed air from the receiver above directly on to the
surface of the water in the chambers, movement and consequent expulsion of the
water must take place, and an upward movement of the machine itself, which will
rise to the surface.
It is evident that if, previously to the expulsion of the water, the nautilus be affixed
to any object below, the power exerted on that object will be exactly proportionate to
the weight of water expelled, and the power will continue increasing until, there
DIVING BELL^ 61
being no fiffther weight to be throirn off, the maximam effect is prodaced. To applj
this power to lifting masses of stone or rock, proper arrangemeDts are affixed to the
centre of the opening in the bottom, by which connection can be made with the
weight, admitting, at the same time, the swinging around of the object suspended,
so that it may be placed in anj required position. In the construction of permanent
work, or the movement of objects whose weight is known, or can be estimated, a
water, or, so called, lifting tube is placed on the side of the water chamber, which in-
dicates the lifting power exercised by the nautilus at any moment The adyantsge
of this gauge will be recognised, inasmuch as without it the closest attention of the
operator, working very cautiously, would be necessary to determine when the weight
was overcome ; by its aid, however, the operator boldly throws open all the valves
necessary to develope the power of the nantilos, watching only the gauge. The
water, having reached the proper level indicating the required lifting power, he knows
the weight must be overcome, or so nearly so that the valve or cocks may be at once
closed, m order that the movement may take place horixontallyk A moment's re-
fieetioii will show that* if there were not an index of this character, carelessness or
inattention on die part of the operator, by leaving the cocks open too long, might
develope a power greater than required, and the nautilus would start suddenly up-
ward. The expansive power of air, acting upon the incompressible fluid, water,
through the opening in the bottom, gives a momentum which, by successive de-
velopments of expansion in the workmg chamber, is constantly increasing in ve-
locity, until, in any considerable depth of water, the result would be undoubtedly
of a very serious character. Take, for exemplification, the nautilus in thirty-three
feet of water, and bottom covers removed, and an equilibrium, at fifteen pounds
to the inch, existing between the air and the water at the level of the bottom of
the machine. Upward movement is communicated the instant the machine rises
in the slightest degree, the existing equilibrium is destroyed, and the highly elastic
qualities of air aasome preponderance, exerting, from the rigid surface of the water
below, an impulsive effort upward in the direction of least resistance. At each suc-
cessive moment of upward movement the impelling power increases, owing to the
increasing disparity between the pressure of air within struggling for escape. The
machine, thus situated, becomes a marine rocket (in reality), in which the propelling
power is exhausted only when the surface is reached, and a new equilibrium is ob-
tained. It will readily be seen that, were this difficulty not overcome, it would be
impossible to govern the nautilus ; for, rising with great velocity to the surface,
the machine is carried above its ordinary flotation, or water line, a little more air
escaping owing to the diminished resistance as thajt level is passed ; the recoil, or
surging downwards, causes a condensation of the air remaining in the chamber ;
a portion of the space previously occupied by air is assumed by water ; the buoyant
power becomes less, the machine settles slightly more by condensation of the air, a
larger space is occupied by water, and the nautilus redescends to the bottom with a
constantly accelerating movement, seriously inconveniencing the operator by filling
more or less with water, according to depth. For many months the difficulties just
enumerated baffled all attempts at control. A weight attached could be lifted, bat
the instant it was entirely suspended, — before the valves could be closed, — upward
movenaent was communicated beyond control This difficulty so fatal has been over-
come by an arrangement at ike bottom of the nautilus, with channels which
radiate fh>m the opening in an inclined direction, debouching at the sides of the
machine. The moment then that the air, by its expansion f^om diminished resist-
ance, or by the introduction fh>m above of a greater volume than can be sustained
by the water* below, reaches, in its downward passage, the level of these chambers,
following the direction of least resistance, it passes through these channels and
escapes mto the surrounding water, without of course affecting the movement of the
machine in the least
The pump for supplying air to the diving bell or other suitable vessel is represented at
fig». 674 and 675, and is constructed as follows : — d is a cylinder, opening at the upper
part into a chamber or chambers r f, separated by a partition s. On the side of
each of these chambers there is a valve h h, opening inwards, and at the upper
part of the same are two valves 1 1, opening outwards into the valve chamber g.
Outside the opening for each of the valves h, h, there is a cup, into which the end
of the water supply pipe K passes ; by this means a small stream of water is supplied
to the cup, and is drawn f^om it into the chamber 7 to supply the waste in the opera-
tion of pumping. The valve chamber o is covered with a jacket A, having a space
between it and the valve chamber that is filled with water fh>m the water pipe m,
which affords a stream of cold water to carry off the heat fh)m the condensed air
which is forced into the chamber. The water thus supplied circulates through the
tubes in the chamber and round them in the jacket, and thus cools the Air in these
E 2
DIVING BELL.
IB thereby Btled with vUer, aod
thus the air is expelled therefrom ■ smsll quan-
tily or (h« wnter pimsiiig with it and coieriog the
TaWcs hj which means they are kept tight and
■wet TTie air nnd -water thna diieharped, after
passing around the siidlU tuheG m the ralre
chamber and beine cooled are forced outward
and conveyed to the condenser On the r«tnrD
stroke of the piston, the other chamber r is filled.
and air and water expelled from it m like manner
through its Talve into the Talve chamber. There
is alvays a sufficient quantity of water in the cy-
linder D and chamber f to fill the latter when
the -water is all expelled ftom the cylinder, by
the piston c haTing been driven to one end of it,
and when the piston returns to the opposite end
of the cylinder the irtiter flows in behind it, and
draws in its equivalent in bulk of air and water
through the valve h. On its return, this is forced
out throngh the valve A into the chamber i, as
Dienliooed above. The water being non-elaHic,
le parts are kept cool enough to avoid raising
n, this procen may be continoed for any length
o> time. A transverse aectioD of this appiiatua is
shown in Jij. 67S.
Figs. 676 and 677 reprMent the tfeakiog tabe
and alarm bell above referred to. The conatmfi-
tion of this mcchsnism is as follows : — There is
a hollow csEting, one portion of which is trian-
if the I
DIVIKG BBXL.
ga]»z in form, (torn one end of whi
■ projt ■ "
screw cut on .
■creved iolo tb« top of the
from the iniide, and pro-
ject* through it to allow
the coupling of ft flexible
or other hose to he at
tached to it. At tlie op
pnsite angle, and in a line
with a, there is a tnbnlsr
projection b, prorided with
a, screw to receive a cap J"
to which is to be attached
a I»ece of hose. Withm
the tuhe/, and at its janc
tioD with b, ie placed a thin
diaphragm of metal oi
oth«r laitaUe material c,
for which pDTpote, how-
ever, a thin silver plate (hat
just fits (he bore of the cap
/" ia preferred. This dia-
phrwm closet all commn-
nicationbetveentbcdiTing
Tesael and the external air.
By this means it is eaa; to
coDverse (hrongh aay re-
qniredlengtliof tnbing. I(
Diaj be desirable to Gt a
■top-cocfc into the tnboUr
projection &, as a precsDtioaarymeBns of preventing the (scape of air in (he event of a
mptnre of the diaphragm. The apper part of the triangnlar enlargemem of ihe
speaking tnbe is ts|iped for a stuffing box at g, withb which there is an aiii A, which
rao* frcan side to side of the said enlargement, and through (he ataSng box st one side.
On this uis i is fixed a lever i within the said enlargement, which lever communicates
with the Enrfaee of the water by means of a wire Gxed at its reversed eod, and ninning
throngh the whole length of pipe. On the oater eitremitf of the axis h ia affixed a
hammer, which strikel oti a bell k conoecled to the tube, as shown in the drawing.
Br tbia means the attention of the operator below may be drawn to the ipeaking tube
when it is required to convene with him from the sarfkce of the water, and the men
wboae duty it is to attend to the operator beh>w can, by placing their ear at the end of
Ihe tabe, hear the bell struck be-
low at a signal (or commanicntioil "°
wltfi them at the snrftce.
The only parts of the apparatus
not vet described are the saw for
catting the (ops of piles to an oni-
furm level, the pump which enables
the divers tbeinselves to rise to the
surface in Ihe event of the flexible
bose being detached or iqjured,
1 the«
an eje bolt into the tide of the
SDoken vessels.
The arrangement of the saw- |
fVame and connections are shown
in fiff. 678. Only u much of the
botium of the Nautilus is shown
■■ will render the pcaition of the
saw imderstood. p is a pile which
is repaired to be out down to Ihe
«ame level a« the others, e is the
blade of the saw, n the framing
by which it is stretched, c, d, the
handle which resu on the cross bar K ; to whicb is attached the upright part of the
handle which is laid hold of by the workman inside when working the i*v. b, a, r.
54
DOCIMACY.
a bent lever ^ith two friction rollers at f which gaides the saw forwards whUe
making the cut . v • i.
Thf pump for ascending in case of accident to the air hose is not shown m the
drawing. It is a simple force pump placed in the working chamber, by whicli the
ballast water in w w, fig. 672, can be pumped out so as to lighten the apparatus «iiB-
cientlj to allow of its ascent
The apparatus for fixing the eye bolts is shown in fig. 679. The operation of this
apparatus is as follows : — It will be observed the chsunber d opens outwards to the
water, so that when the sliding partition or valve y is forced down by the lever g, the
communication of the water with the chamber c is cut off. The lid z being removed,
a bolt i ^or other operating tool or instrument) is placed within the chamber c ; the
rod k is forced through the stuflBng box / until the recessed end of the rod contains
the end of the bolt ; the small rod j is then screwed through the stuffing box n, until
the screw on the end of this rod has become affixed to the end of the bolt contained
within the recess at p. The lid z of the chest is then fastened on, and the partition
or valve y raised, the stuffing box m preventing the escape of air. Communication is
thus opened between the chambers a and d, the latter b«ingopen outwards. The rod
i is now pushed outwards by pressing on the handle k through the stuffing box /,
nntil the vessel or object to be operated upon is reached, when the operation is per-
769
s
s -
» -
\
1 -
> —
I - -
> r •■
\
ibrmed as required. It will be observed that the stuffing box prevents the escape of
air out of the bell or the admission of water into it, the stuffing box n having the same
tendency. After the operation with the tool or instrument is complete, the rod k is dis-
connected by unscrewing the rod j, and is drawn into the chamber a by means of the
handle k ; the partition or valve y is again lowered, and the operations above described
arc repeated. It will hence be obvious that a number of eye bolts might in this manner
be successfully inserted in the side of a sunken vessel from the diving bell, so that bj
hooking on the ** camels *' the strain would be so distributed as to prevent injory by
the process of lifting the toid vessel.
DOCIMACY. !Brom the Greek AoKifta^'w, I prove (^Docimasie, Fr. ( Probierhaui,
Germ. ), is the art by which the nature and proportions of an ore are determined.
The art of assaying minerals, the separation of the metaL This analjrtical examina-
tion was originally conducted in the diy way, the metal being extracted from its mine-
ral isers* by means of heat and certain fluxes. But this method was eventually found
to be insufficient and even fallacious, especially when volatile metals were in question,
or when the duxes could absorb them. The latter circumstance became a very serions
evil, whenever the object was to appreciate an ore that was to be Worked at great ex-
pense. Bergmann first demonstrated, in an elaborate dissertation, that the humid ana*
lysis was much to be preferred ; and since his time the dry way has been devoted
chiefly to the direction of metallnrgic operations, or, at least, it has been employed
merely in concert with the humid, in trials upon the small scale.
AfWr discovering an ore of some valuable metal, it is essential to ascertain if its
quantity and state of combination will justify an adventurer in working the mine, and
smelting its products. The metal is rarely found in a condition appfoadiing to purity ;
it is often disseminated in a ^angue far more bulky than itself; and more frequently
still it is combined with simple non-metallic substances, such as sulphur, carbon,
ehlorine, oxygen, and acids, more or less difficult to get rid of. In these compound
states its distinctive characters are so altered, that it is not an easy task either to re>
cognise its nature, or to decide if it can be smelted with advantage. The assaycr.
DONARIUM. 55
without neglecting any of the external characters of the ore, teeks to penetrate, so to
speak, into its interior ; he triturates it to an impalpable powder, and then subjects
it to the decomposing action of powerful chemical reagents ; sometimes, with the aid
of alkalies or salts appropriate to its natnra, he employs the dry way by fire alone ; at
others, be calls in the solvent power of adds with a digesting heat ; happy, if after a
series of labours, long, Taried, and intricate, he shall finally succeed in separating a
notable proportion of one or more metals either in a pure state, or in a form of com-
hioation such that from the amount <^ this known compound, he can infer, with
precision, the quantity of fine metal, and thereby the probable value of the mine.
The blow-pipe, skilfully applied, affords ready indications of the nature of the me-
tallic constituents, and it is therefore usually the preliminary test The separation of
the several constituents of the ore can be effected, however, only by a chemist, who
joins to the most extensive knowledge of the habitudes of mineral substances, much
experience, sagacity, and precision in the conduct of analytical operations. Under
the individual metals, as also in the articles BiiOWpzPB, Assay, Metalldrgt, Minks,
and Ores, are presented such a copious and correct detail of docimatic processes, as
will serve to guide the intelligent student through this labyrinth.
DOEGLING TRAIN OIL. The oil of the Balana rostrata, or Bottle-nose whale.
DOGWOOD. Comtu sangumea, a small underwood known as the wild cornel,
and as the conunon Dogwood. Little splinters of this wood are used by the watch-
makers for cleaning out the pivot-holes of watches, and by the optician for cleaning
deeply-sealed small lenses. Its peculiarity is that it is remarkably free from silex.
Toothpicks are also manufiictured from dogwood.
DOIXY. DOLLY TUB. A minim^ term applied to a tub fitted with a perforated
bcMird, the doXbf^ to which a circular motion is given by a winch-handle, and thus im-
pe^ts a similar motion to the ore. See Minino and Ores, Drbssino of.
DOLOMITE. JUagnesian Limestone. This rock occurs in very (p'eat abundance
in various parts of England, especially in Yorkshire, Nottinghamshire, and Somerset.
It is largely employed as a building stone.
Karsten infers, from his numerous analysles of dolomite, that in those which are
crystallised, the carbonate of lime is always combined in simple equivalent propor-
tion with another carbonate, which may be carbonate of magnesia fdone, or together
with carhonates of iron or manganese, and sometimes both. In the uncrystallised
varieties of dolomite, the diversity in the proportion of lime and magnesia is inde-
finite, but such masses must be regarded as mere mixtures of true dolomite and car-
bonate of lime. Acids do not produce a perceptible effervescence with dolomite,
except when digested with it in fine powder. Karsten found that dilute acetic acid
extracts from dolomites, at a temperature below 32^ Fahr., only carbonate of lime,
while a dolomitic mass remains undissolved. Hence he regards them as mixtures of
dolomite with unaltered carbonate of lime. — Buckof.
Sulphate of magnesia has been manufactured from dolomite on the large scale.
Dr. William Henrv, of Manchester, patented a process of the following kind : —
Calcine magnesian limestone so as to expel the carbonic acid ; then convert the
caustic lime and magnesia into hydrates by moistening them with water ; afterwards
add a sufficient quantity of hYdrochloric, nitric, or acetic acid, or chlorine to dissolve
the lime, but not the magnesia, which, after being washed, is converted into sulphate
by sulphuric acid, or, where the cost is objectionable, by sulphate of iron, which is
easily decomposed by magnesia. Or the mixed hydrates of lime and magnesia are
to be added to bittern : chloride of calcium is formed in solution, while two portions
of magnesia (one from the bittern, the other from the magnesian lime) are left unacted
CO. Hydrochlorate of ammonia may be used instead of bittern : by the reaction of
this on the hydrated magnesian lime, chloride of calcium and caustic ammonia remain
in solution, while magnesia is left undissolved ; .the ammonia is separated from the
decanted liquor by distillation.
In some chemical works on the Tyne, the dolomites fW>m the coast around Marsden
are treated with sulphuric acid, and the sulphate of magnesia {Epsom salts) separated
from the sulphate of lime by crystallisation.
The dolomite has also been employed by the late Hugh Lee Pattinson for the ma-
nufacture of the Carbonate of Magnesia, which see.
DONARIUM. Dr. Bergmann received through Mr. Krantz a mineral from
Brerig in Norway, which is found in the same zircon-syenite that contains wohlerite
and eukolite, and he discovered in it the oxide of a new metal combined with silicic
acid. This metal he calls Donarhtm, after the god Donar, and he assigns to it the
symbol — Do.
The silicate of the oxide of Donarinm, Do*0»,SiO» + 2HO, is yellowish red, in
some fragments passing into brown, in others into yellow ; when scratched or pow-
dered, it is light orange. In thin films it is almost transparent, the thicker ones
S 4
66 DRAGON'S BLOOD.
transladd. Some pieces have a distinctly laminated stracture, in others the fractare
is more fiat, or conchoidal. Its hardness is between that of finor spar and apatite ; its
specific gravity «» 5*397.
Small films heated in a platina spoon break down into a dark brown* mass, which
reassumes an orange colour when cold; the larger pieces lose their transparency. By
heating it in a glass tube, watery vapour is driven oS, Fragments held by the pla-
tina forceps in the flame of a spirit lamp decrepitate. Heated by the blowpipe on
charcoal, it does not melt, a slight vitrification being sometimes observed on the
edges, perhaps in consequence of the intermixture of some foreign substance. Fused
with soda, the silicic acid is dissolved. The other constituents are seen in the non-
transparent mass, by the help of a glass, as small yellow particles. Borax yields a
yellow bead, which is colourless when cold. The phosphates produce in the external
part of the flame a reddish glass, which is colourless when cold ; in the inner part of
the flame the bead becomes yellow, and when cold is colourless.
The mineral, containing donarium, is readily decomposed by acids, and yields when
treated by hydrochloric acid a clear and transparent gelatinous matter. At the same
time some carbonic acid is evolved. The colour of the solution is deep yellow, like that
of a concentrated solution of iron. The mineral is also affected by diluted acids, even
by tartaric acid. After having been exposed to a strong heat, the essential parts of
mineral are no longer acted upon even by concentrated acids.
The analysis showed tho presence of lime, water, and the new oxide, also some
traces of magnesia, manganese, carbonate of soda, and iron.
The oxide of donarium belongs to the class of earthy bodies, and ranks next to
zirconia and yctria. The hydrate, which is thrown down by ammonia of a beautiful
white colour, becomes yellow, and at Isst yellowish red, losing its hydrate water in the
air. B}*^ heat the latter is completely removed, and the oxide, which is insolnble in
muriatic acid, can be perfectly deprived by this acid of the contained iron. Analysis
showed the constituents to be : —
Silicic acid -----. 17*625
Oxide of donarium - - - * . 71 •247
Carbonate of lime ...... 4*042
Oxide of iron - - - . . 0*310
Magnesia and oxide of manganese < - - 0*214
Potash and soda . - . . . 0*303
Water ---..- 6*900
100*641
See Ure*8 Dictionary of Chemistry,
DONKEY ENGINE. A very small engine employed to pump water into boilera.
If the use of the donkey engine was more usual than it is we should hear less of steam
boiler explosions. •
DOOt^ARA RESIN. A resin obtained in considerable quantities in the East Indies
from the Vateria Indica, which is used as a fragrant incense in the temples, makes
an excellent varnish, and is sometimes called JSast Indian Copal^ or Gum Ptiuy.
— Simmonds,
DORNOCK, is a species of figured linen of stout fabric, which derives its name
f^om a town in Scotland, where it was first manufiictured for table-cloths. It is the
most simple in pattern of all the varieties of the diaper or damask style^ and therefore
the goods are usually of coarse quality for common household wear. It receives the
figure by reversing the flushing of the warp and woof at certain intervals, so as to
form squares, or oblong rectangles upon the cloth. The most simple of these is a suc-
cession of alternate squares, forming an imitation of a checker board or mosaic work.
The coarsest kinds are generally woven as tweels of three leaves, where every thread
floats over two, and is intersected by the third in succession. Some of the finer are
tweels of four or five leaves, but few of more ; for the six and seven leaf tweels aie
seldom or never used, and the eight leaf tweel is confined almost exclusively to
damask.
DOWN. See Feathers. Down imported in 1857, 5,208 lbs.
DRAGON'S BLOOD {Sang dracon, Fr. ; Drachenbfut, Germ.) is a resinous
substance, which comes to us sometimes in small balls of the siae of a pigeon's egg,
sometimes in rods, like the finger, and sometimes in irregular cakes. Its colour, in
lump, is dark-brown red; in powder, bright red ; friable ; of a shining fracture; specific
gravity 1*196. It contains a little benzoic acid, is insoluble in water, but dissolves
readily in alcohol, ether, and oils. It is brought from the East Indies, Africa, South
America, as the produce of several trees, the Dracana draco, the Pterocarpus santa-
Unu8, Pterocarpus draco, and the Calamus rotang.
DRAWING CHALKS. 57
Dragon's blood is used chiefly for Ungeing spirit and turpentine Tarnishes, for pre*
paring gold lacquer, for tooth tinctures and powders, for staining marble. Sec Ac*
cording to Herbenger, it consists of 9*07 parts of red resin called X>racoiitii, 2 of fixed
oil, 3 of benaoic acid, 1 -6 of oxalate, and 3*7 of phosphate of lime. According to
Johnstone, the resin of lump dragon's blood has the formula C^H'^O*, that of reed
dragon's blood, C*H«»0».
Pereira, enumerates the following varieties of this substance found in commerce: —
1. Dmgon^M biood in the reed; Dragon's Uood in sticks; Siinguis Draconis in
baculia,
2. DragtnCs Hood in oval masses; DragotCs Wood m drops; Sanguis Draconis in
lachrymis.
3. Dragon^s blood in powder.
4. Dragon's Wood in the tear ; Sanguis Draconis in grants.
5. Lump Dragon^s Wood ; Scmguis Draconis in massis.
Besides these, there are Dragon*s Wood in cakes, and False Dragon*s Wood in oval
DRAINING TILES. Burnt clay tiles, generally shaped in section like a horse
shoe, about one foot long and two or three inches broad. These are much used in
agricultural draining. See Stoivb-warb.
DRAWING CHALKS. Chalks or crayons are frequently nothing more than the
natural production reduced to a conrenient form : they are, however, sometimes pre-
pared artificially ; a few of these manufactures are named.
The brothers Joel, in Paris, employ as crayon cement the following composition :
6 parts of shellac, 4 parts of spirit of wine, 2 parts of turpentine, 12 parts of a
colouring powder, such as Pru$sian>blue, orpiment, white lead, vermilion, &c., and
12 parts of blue da^. The clay being elutriated, passed through a hair sieve, and
dried, is to be well incorporated by trituration with the solution of the shellac in the
spirit of wine, the turpentine, and the pigment ; and the doughy mass is to be
pressed in proper moulds, so as to acquire the desired shape. They are then dried
by a stove heat.
In order to make cylindrical crayons, a copper cylinder is employed, about 2 inches
in diameter, and 1^ inch long^ open at one end, and olosed at the other with a per-
forated plate, containing holes corresponding to the sizes of the crayons. The paste is
introduced into the open end, and forced through the holes of the bottom by a piston
moved by a strong press. The vermicular pieces that pass through are cut to the
proper lengths, and dried. As the quality of the crayons depends entirely upon the
fineness of the paste, mechanical means must be resorted to for effecting this object in
the best manner. The following machine has been found to answer the purpose
exceedingly welL
JFig. 680 is a vertical section through the centre of the crayon milL Fig. 681 is a
view of the mill from above, a, the mill tub, whose bottom b must be a hard flat plate
of cast-iron ; the sides a being of wood or iron at pleasure. In the centre of the
bottom there is a pivot c, screwed into a socket cast upon the bottom, and which may
be strengthened by two cross bars d, made fast to the fhime e. r, the millstone of
cast-iron, concave, whose diameter is considerably smaller than that of the vessel
A; it is furnished within with a circular basin of wood a, which receives the mate-
rials to be ground, and directs them tot he holes h, which allows them to pass down
between the under part of the muUer, and the bottom of the tub, to undergo tritur-
ation.
By the centrifagal motion, the paste is driven towards the sides of the vessel, rises
over the sides of the muller, and comes again through the holes n, so as to be
repeatedlv subjected to the grinding operations. This millstone is mounted upon an
upright shaft i, which receives a rotatory motion from the bevel-work k, driven by
the winch i.
The furnace in which some kinds of crayons, and especially the factitious black-
lead pencils, are baked, is represented in^^r. 682, in a fW>nt elevation ; and in^. 683,
which is a vertical section through the middle of the chimney.
A A, six tubes of greater or less size, according as the substance of the crayons is a
better or worse conductor of heat These tubes, into which the crayons intended for
baking are to be put, traverse horizontally the laboratory b of the furnace, and are
supported by two plates c, pierced with six square holes fbr covering the axles of the
tubes A. lliese two plates are hung upon a common axis d ; one of them, with a
ledge, shuts the cylindrical part of the furnace, as is shown in the figure. At the
extremity of the bottom the axis d is supported by an iron fork fixed in the brick-
work ; at the front it crosses the plate c, and lets through an end about 4 inches square
to receive a key, by means of which the axis d may be turned round at pleasure, and
thereby the two plates c, and the six tubes a, are thus exposed in succession to the
action of the fire in an equal manner upon each of their sides. At the two extremities
DRY GEINDIMG.
fuel u iotrodaced ; Q,Jig. 683, the uh-pit ; b, the flre-pUce ; i holes of the gnoe
irhich Bcparate the flre-plsce from the ash-pit ; e, brickwork exterior to the furnace.
General Lomet proposes the following composition for red crayoni. He tikei the
■oftcst fariDntiCe, grinds it upon a porphfrj (lab ; and then earefullj elatnates it. He
makes it into plastic paste arith gum arabic and a little irbite soap, which he forms by
moulding, as aboTe, through a sjriage, and drying JQto crayons. The proportioot
of tlie ingredients require to be carefully studied.
Chiyuns or Chalks, lithographic. Vuioua formnlie have been given fbrthe fonna-
tion of these crayons. One of these prescribes nhite wax, 4 parts ; hard tdlow-soap,
shellac, of each S parts; lamp black, 1 part. Another is, dri^ (allow-soap and «bite
wai, each n parts ; lamp black, 1 part. This miiture being fused with a gentle heat,
is lo be cast into moulds for forming crayons of a proper size. See LiTnooRAPor,
DRUGGET is a coarse, but rather slight, wooUen nbric, used fbr covering carpets,
aod as an article of clothing by females of the poorer classes. — Vrt.
The manofncture of druggets of various kinds has been of late years considerably im-
proved, and carpets, many of them handsomely figured, are now found in common
DRY GRINDING. The practice of employing dry_ stones has been long adopted
for the purpose of quickening the processes of sharpening and polishing stwl goodie
Tbe dry dusi from the sand-stone, mixed with the tine particles of steel, being inhaled
by the workmen, produces diseases of the pulmonary organs to such an extent, that
needle and fork grinders are reported rarely to lii~e beyond the ages of twenty-five or
thirty,
Mr, Abraham, of Sheffield, Grst invented magnetic guards, which, being placed
close to the grindstone, attracted the particles of steel, and thos protected the men
from their influences. Still they suffered from the effects of the fine sand-durt, »nd
the grinders heedlessly abandoned the use of them altogether.
Mr. Abraham devised another plan, which is employed, although only partially, in
the Slieffield works. The grindstone is enclosed in a wooden case, which only ex-
poses a portion of the edge of tbeslonei a horizontal lube proceeds as a tangent from
the opper surface of the circle to the external atmosphere. The current of air gener-
ated by the stone in rapid revolution, escaping through the tube, carries off with it
nearly all the dust arising fVom ttie process. It is curious to find so simple a cMi-
trivsnce frequently rrjecled by Ibe workmen, notwithstanding that sad experieoc*
teaches them, that they are (hereby exposing themselves to the influenee* of an atmo-
■phere which produces slowly but snrely their dissolution.
DYEING.
59
DRYING OILS. When oilt, especially linieed and nut oik, are boiled with litharge
or oxide of lead, ihey acqnire the property of solidifying or drying quickly on expo-
sure to the atmosphere. These are very useful to the painter, as without them the
pigments with which they are mixed would remain soft. The oxide of lead appears
to estaUish a state of more easy oxidation in the oils, so that they assume readily the
conditions of a resin.
DRY ROT. A peculiar decomposition which takes place in wood, dependent upon
a process of oxygenation. See Wood.
DTJCTlLlTi (Sireckiarckeit, Germ.) is the property of being drawn out in length
without breaking, possessed in a pre-eminent degree by gold and silver, as also by many
other metals, by glass in the liquid state, and by many semifluid, resinous, and
gammy substances. The spider and the silkworm exhibit the finest natural exercise
of ductility upon the peculiar viscid Mcretions firom which they spin their threads.
¥rhea a body can be readily extended in all directions under the hammer, it is
said to be malleable, and when into fillets under the rolling press, it is said to be
laminable.
Talkie of the DvctiUty and MaUeahUity of Mttah.
Metflto Ductile and
Brittle MetaU
MetaU In the Order
MeUl« in the Order
Malleable in Alpha-
in
of their AViredrawing
of their Laminable
beCkal Order.
AlphabeUcal Order.
Ductility.
Ductility.
Cadmium.
Antimony.
Gold
Gold.
Copper.
Arsenic.
Silver.
Silver.
Gold.
Bismuth.
Platinum.
Copper.
Iron.
Cerium ?
Iron.
Tin.
Iridium.
Chromium.
Copper.
Platinum.
Lead.
Cobalt
Ziuc.
Lead.
Magnesium.
Columblum ?
Tm.
Zinc.
Mercury.
Iridium.
Lead.
Iron.
NickeL
Manganese.
Nickel.
Nickel.
Osmium.
Molybdenum.
Palladium?
Palladium ?
Palladium.
Osmium.
Cadmium?
Cadmium ?
Platinum.
Rhodium.
Potassium.
Tellurium.
Silver.
Titanium.
Sodium.
Tungsten.
Tin.
Uranium.
Zinc.
There appears to be therefore a real difference between ductility and malleability ;
fcr the metals which draw into the finest wire are not those which afford the thinnest
leaves under the hammer or in the rolling press. Of this fact iron affords a good
illustration. Among the metals permanent in the air, 17 are ductile and 16 are brittle.
Bat the most ductile cannot be wire-drawn or laminated to any considerable extent
without being annealed from time to time during the progress of the extension, or
rather the sliding of the particles alongside of each other, so as to loosen their lateral
cohesion.
DCLSE. The jRhodomefiia palmata. See AixiiB.
DUNES. Low hills of blown sand, which are seen on the coasts of Cheshire and
Cornwall, in this country, and also in many places skirting the shores of Holland and
Spain.
DUNGING, in calico-printing, is the application of a bath of cowdnng, diffused
through hot water, to cotton goods in a particular stage of the manufacture. Dunging
and scouring are commonly alternated, and are two of the most important steps in the
process. See Calico Printiho.
DUTCH LEAF or FOIL, a composition of copper and lime, or of bronze and
copper leaf. See Allots, Brass, and Bronze Powdsrs.
DUTCH RUSH. EquUetum Hyemah, This rush is known also as the Large
hranchleu Horse'tail. The dried stems are much employed for polishing wood and
metal. For this purpose they are generally imported from Holland.
DYEING (Teinture, Fr. ; Fiirberei, Germ.) is the art of imparting to and fixing
upon wool, silk, cotton, linen, hair, and skins any colour, with sufficient tenacity, not
to be removed by water or the ordinary usage to which these fibrous bodies are
exposed when worked up into articles of raiment or furniture. We shall here consider
the general principles of the art, referring, for the particular dyes and the manner of
€0
DIVING BELL.
opening from the chambers ontwards, is opened, in order that, the air escaping, an
uninterrupted flow of water may take place into the chambers. The weight of water
entering the chambers causes a destrnction of the buoyancy of the machine, and
the nautilus gradually sinks. As soon as it is fairly under water, in order that
the descent may be quiet and without shock, the water-cock &, is closed. The re-
ceiver at the surface being previously charged by the air pump to a density some-
what greater than that of Uie water at the depth proposed to attain, one of the
branch-cocks on the pipe c c, connecting the chambers at top, is opened, and the air
rushes into the working chamber, gradnally condensing until a density equal to the
density of the water without is attained ; &is is indicated by proper air and water
gauges. These gauges marking equal points, showing the equilibrium of forces
without and within, the cover to the bottom z is removed or raised, and communica-
tion is made with the under water surface, on which the nautilus is resting. In order
to move about in localities where tides or currents do not affect operations, it is only
necessary for the workman to step out of the bottom of the nautilus, and placing the
hands against its sides, the operator may move it (by pushing) in any direction.
Where currents or tides, however, have sway, it becomes necessary to depend upon
fixed points from which movements may be made in any direction. This is accomplished
by placing, in the bottom of the nautilus, stuffing boxes of peculiar construction (m m,
fig. 672), through which cables may pass over pulleys to the external sides, thence
up through tubes (to prevent their being worn), to and over oscillating or swinging
pulleys, placed in the plane of the centre of gravity of the nautilus, and thence to
the points of affi&ment respectively (Jig. 673). The olgect to be gained by having
673
the swinging pulleys in the plane of the centre of gravity of the mass, is to hold the
machine steady and to prevent oscillation. Within the machine, and directly over the
above stuffing boxes, are windlasses for winding in the cables. By working these
windlasses movement may be effected, and of course the number of these cables will
depend on the variable character of the situation to be occupied. Having thus
secured the means of descending, communicating with the bottom, and of movement,
the next point is to ascend. Weight of water has caused a destruction of buoyancy
at first, and consequent sinking ; if then any portion of this water is removed, an
upward effort will at once be exerted exactly proportionate to the weight of water
thrown off. The air in the receiver at the surface being constantly maintained at a
higher density than that of the water below, if we open the water cock on the top
pipe, c, c, throwing the condensed air from the receiver above directly on to the
surface of the water in the chambers, movement and consequent expulsion of the
water must take place, and an upward movement of the machine itself, which will
rise to the surface.
It is evident that if, previously to the expulsion of the water, the nautUus be affixed
to any object below, the power exerted on that object will be exactly proportionate to
the weight of water expelled, and the power will continue increasing until, there
DIVING BELL^ 61
Leing no fiother weight to be throirn off, the maximam effect is produced. To applj
thia power to lifting masses of stone or rock, proper arrangeoients are affixed to the
centre of the openiDg in the bottom, bj which connection can be made with the
weight, admitting, at the same time, the swinging around of the otgect suspended,
so that it may be placed in any required position. In the construction of permanent
work, or the moTcment of objects whose weight is known, or can be estimated, a
water, or, so called, lifting tube is placed on the side of the water chamber, which in-
dicates the lifting power exercised by the nautilus at any moment The adrantage
of this gauge will be recognised, inasmuch as without it the closest attention of the
operator, working Tery cautiously, would be necessary to determine when the weight
was overcome ; by its aid, howerer, the operator boldly throws open all the yalves
necessary to develope the power of the nautilus, watching only the gauge. The
water, having reached the proper level indicating the required lifting power, he knows
the weight must be overcome, or so nearly so that the valve or cocks may be at once
closed, m order that the movement may take place horizontally^ A moment's re-
fleetioii will show that, if there were not an index of this character, carelessness or
inattention on the part of the operator, by leaving the cocks open too long, might
develope a power greater than required, and the nautilus would start suddenly up-
ward. The expansive power of air, acting upon the incompressible fluid, water,
through the opening in the bottom, ^ves a momentum which, by successive de-
velopments of expansion in the working chamber, is constantly increasing in ve-
locity, until, in any considerable depth of water, the result would be undoubtedly
of a very serious character. Take, for exemplification, the nautilus in thirty-three
feet of water, and bottom covers removed, and an equilibrium, at fifteen pounds
to the inch, existing between the air and the water at the level of the bottom of
the machine. Upward movement is communicated the instant the machine rises
in the slightest degree, the existing equilibrium is destroyed, and the highly elastic
qualities of air assome preponderance, exerting, from the rigid surface of the water
below, an impulsive effort upward in the direction of least resistance. At each suc-
cessive moment of upward movement the impelling power increases, owing to the
increasing disparity between the pressure of air within struggling for escape. The
machine, thus situated, becomes a marine rocket (in reality), in which the propelling
power is exhausted only when the surface is reached, and a new equilibrium is ob-
tained. It will readily be seen that, were this difficulty not overcome, it would be
impossible to govern the nautilus ; for, rising with great velocity to the surface,
the machine is carried above its ordinary flotation, or water line, a little more air
escaping owing to the diminished resistance as thajt level is passed ; the recoil, or
surging downwards, causes a condensation of the air remaining in the chamber ;
a portion of the space previously occupied by air is assumed by water ; the buoyant
power becomes less, the machine settles slightly more by condensation of the air, a
larger space is occupied by water, and the nautilus redescends to the bottom with a
constantly accelerating movement, seriously inconveniencing the operator by filling
more or less with' water, according to depth. For many months the difficulties just
enomerated baffled all attempts at control. A weight attached could be lifted, but
the instant it was entirely suspended, — before the valves could be closed, — upward
movement was communicated beyond control This difficulty so fatal has been over-
come by an arrangement at the bottom of the nautilus, with channels which
radiate from the opening in an inclined direction, debouching at the sides of the
machine. The moment then that the air, by its expansion fh>m diminished resist-
ance, or by the introduction from above of a greater volume than can be sustained
by the water below, reaches, in its downward passage, the level of these chambers,
following the direction of least resistance, it passes through these channels and
escapes into the surrounding water, without of course affecting the movement of the
machine in the least
The pump for supplving air to the diving bell or other suitable vessel is represented at
fiS9, 674 and 675, and is constructed as follows : — d is a cylinder, opening at the upper
part into a chamber or chambers f f, separated by a partition e. On the side of
each of these chambers there is a valve h h, opening inwards, and at the upper
part of the same are two valves 1 1, opening outwards into the valve chamber o.
Outside the opening for each of the valves h, h, there is a cup, Into which the end
of the water supply pipe K passes ; by this means a small stream of water is supplied
to the cnp, and is drawn firom it into Uie chamber f to supply the waste in the opera-
tion of pumping. The valve chamber o is covered with a jacket K, having a space
between it and &e valve chamber that is filled with water fi-om the water pipe m,
which affords a stream of cold water to carry off the heat from the condensed air
which is forced into the chamber. The water thus supplied circulates through the
tubes in the chamber and ronnd them in the jacket, and thus cools the ftir in these
E 2
62 DYEING.
nounced as a dangerous drug, and forbidden to be used, by our parliament in the r«gn
of Queen Elizabeth. An act was passed authorising searchers to bum both it and log^
-wood in every dye-house where they could be found. This act remained in full force
till the time of Charles II. ; that is, for a great part of a century. A foreigner might
have supposed that the legislators of England entertained such an affection for their
native woad, with which their naked sires used to dye their skins in the old times,
that they would allow no outlandish drug to come in competition with it. A most
instructive book might be written illustrative of the evils inflicted upon arts, manu-
factures, and commerce, in consequence of the ignorance of the legislature."
More recently another class of dye-drugs have been introduced, and have super-
seded some of those of the former century ', these are bichromate of potash, red and
yellow prussiate of potash, manganese, catechu, arsenic, &c.
Colours are not, properly speaking, material ; they are impressions which we receive
from the rays of light reflected, in a decomposed state, by the surfaces of bodies. It is
well known that a white sunbeam consists of an indeterminate number of d^erently
coloured rays, which, being separated by the refractive force of a glass prism, form the
solar spectrum, an image divided by Kewton into seven sorts of rays ; the red, orange,
yellow, green, blue, indigo, and violet Hence, when an opaque body appears ocJoored,
for example, red, we say that it reflects the red rays only, or in greatest abundance,
mixed with more or less of the white beam, which has escaped decomposition. Accord-
ing to this manner of viewing the colouring principle, the art of dyeing consists in
fixing upon stuffs, by means of corpuscular attraction, substances which act upon light
in a different manner from the surfaces of the stuffs themselves. The dyer ought, there-
fore, to be familiar with two principles of optics ; the flrst relatively to the mixture of
colours, and the second to their simultaneous contrast.
Whenever the different coloured rays, which have been separated by the prism, are
totally reunited, they reproduce white light. It is evident, that in this composition
of light, if some rays were left out, or if the coloured rays be not in a certain proportion,
we should not have white light, but light of a certain colour. For example ; if we
separate the red rays from the light decomposed by a prism, the remaining coloured
rays will form by their combination a peculiar bluish green. If we separate in like
manner the orange rays, the remaining coloured rays will form by their combination
a blue colour. If we separate from the decomposed prismatic light the rays of greenish
yellow, the remaining coloured rays will form a violet. And if we separate the rays of
yellow bordering on orange, the remaining coloured rays will form by their union an
indigo colour.
Thus w% see that every coloured light has such a relation with another coloured light
that, by uniting the first with the second, we reproduce white light; a relation which
we express by saying that the one is the complement of the other. In this sense, red
is the complementary colour of bluish green ; orange, of blue; greenish yellow, of
violet ; and orange yellow, of indigo. If we mix the yellow ray with the red, we
produce orange ; the blue ray with the yellow, we produce green ; and the blue with
the red, we produce violet or indigo, according as there is more or less red relatively
to the blue. But these tints are distinguishable from the orange, green, indigo, and
violet of the solar spectrum, because when viewed through the prism they are reduced
to their elementary component colours.
If the dyer tries to realise the preceding results b^ the mixture of dyes, he will
succeed only with a certain number of them. Thus, with red and yellow he can make
orange; with blue and yellow, green; with blue and red, indigo or violet. These
facts, the results of practice, have led him to the conclusion that there are only three
primitive colours ; the red, yellow, and blue. If he attempts to make a white, by
applying red, yellow, and blue dyes in certain quantities to a white stuff, in imitation
of the philosopher's experiment on the synthesis of the sunbeam, far ftom succeeding,
he will deviate still further from his purpose, and the stuff will by these dyes become
coloured of a depth varying according to the quality of the stuff used ; until a full
black is produced. Nevertheless, the principle is applicable, and in many cases
adopted in practice by blending the yellow, red, and blue rays in order to produce or
improve an otherwise imperfect white. When a little ultramarine, cobalt blue,
Prussian blue, or indigo is applied to bleached goods with the view of giving them
the best possible white, if only a certain proportion be used, the goods will appear
whiter after this addition than before it In this case the violet blue forms with the
brown yellow of the goods a mixture tending to white, or less coloured than the
yellow of the goods and the blue separately were. For the same reason a mixture of
Prussian blue and cochineal pink, or archil and cudbear, is used for whitening of
silks in preference to a pure blue, for on examining closely the colour of the silk to be
neutralised, it was found by the relations of the complementary colours, that the
violet was more suitable than the pure blue alone. The dyer should know, that
DYEING. 63
when lie applies aeiwenX different coloaring matters to stuff, as yellow and Mae
separately, &ey will appear green, not because the colouring matters have combined,
but because the eye cannot distinguish the points which reflect the yellow from those
which reflect the blue, and it is this want of distinction that produces the combined
colour. With such a dye the colour will appear of different tints, the blue or yellow
prevailing according to the position in which it is placed to the eye, whether seen
by reflected or transmitted, light, but when the dye applied to the stuff is in chemical
union, producing a green, such as arsenite of copper the yellow and blue rays cannot
be thns distinguish^ Otber instances of mixed colours will be seen by examining
certain grey substances, such as hairs, feathers, &c« with the microscope, by which
it is seen grey colour results fh>m black points disseminated over a colourless or
slightly coloured surfiioe. The microscope may be thus usefully applied by the dyer
to distinguish whether a colour be the result of a mixed or a combined dye.
The dyer should also be acquainted with the law of the simultaneous contrast of
colours. When the eye views two colours close alcmgside of each other, it sees
them differing most, in the height of their tone, when the two are not equally pale or
fuU^bodied. They appear most different, when the complementary of the one of them
is added to the colour of the other. Thus, put a green alongside of an orange, the
led colour complementary of green being added to the orange, will make it appear
redder. And in like manner, the blue complementary of orange being added to the
green, will make it appear more intensely blue.
It is not sufficient to place complementary colours side by side to produce harmony
of colour, the respective intensities having a most decided influence ; thus, pink and
light green agree, red and dark green al»o ; but light green and dark red, pink and
dark green do not, therefore, to obtain the maximum of effect and perfect harmony,
the following colours must be placed side by side, taking into account their exact
iBtensity and tint
FrimUir« Coloar. Secondary Coloan.
{Light blue
Yellow
Red
fRed
Blue - - - Orange - - - ^ Yellow
Yellow orange » - Indigo
Oreenish yellow - Violet
Black - - White
LBlne
fBlue
4 Red
Yellow
fRed
Blue
Yellow
Yellow
Blue
Red
The mixed contrast gives the reason why a brilliant colour should never be looked at
for any length of time, if its true tint or brilliancy is to be appreciated; for if a person
looks, for example, at a piece of red cloth for a few minutes, green, its complementary
colour is generated in the eye, and adding itself to a portion of Uie red, produces
black, which tarnishes the beauty of the red. This oontrast explains why the shade
of a coloar, may be modified according to the colour which the eye has previous
looked at, either favourably or otherwise. An example of the first instance is noticed,
when the eye first looks to a yellow substance, and then to a purple one ; and as
exemplifying the second case looking at a blue and then at a purple.
The relations of dyeing with the principles of chemistry, constitute the theory of
the art, properly speaking ; this theory has for its basis the knowledge —
1st. Of the nature and properties of the bodies which dyeing processes bring into
contact.
2nd. Of the circumstances in which these bodies are brought together, facilitating
or retarding their action.
3rd. The phenomena which appear during their action ; and,
4th. Properties of the coloured combinations which are produced.
The first of these generalities embrace a knowledge of the preparations, which
stuff necessarily undergoes previous to dyeing, and also the preparations of the dye-
drug before bringing it into contact with the stuff.
The operations to which stuffs are subjected before dyeing, are intended to separate
from them any foreign matters which may have become attached, or are naturally
64 DYEING.
inherent in the staff. The former are sach as have been added in the spiDiiiog,
weaving, or other manipulations of the manufacture, and are all removed by
steeping in an alkaline lye and washing. The secondare the natural yellow coloQring'
substances which coat some of the various 6bres, both vegetable and animal ; and the
chlorophylle, or leaf-green of vegetables The removal of these is generally effected
by boiling in soap and alkaline lyes. A weak bath of soda, in which the stuff is
allowed to steep for some time, and then washed in water, is generally the only pre-
paration required for wool, in order that it may take on a uniform dye.
To remove the gummy or resinous matter from silk, it requires boiling in soap lye;
however, its removal is not essential to the stuff combining with the dye, as silk is often
dyed while the gum remains in it, in which case it is only rinsed in soap lye at a very
moderate heat, to remove any foreign matters imbibed in the process of manufactore.
Vegetable fibre, as cotton, has such natural resinous matters that retard the re-
ception of the dye removed by boiling, either with or without alkaline lyes ; bat the
natural dun colour of the fibre is not removed, which from the laws of light and
colour already referred to, would interfere with the production of bright light tints;
under these circumstances, the natural colour of the fibre has to be previously removed
by bleaching, for which see the article. Bleaching.
The necessary preparation of the dye-drugs within the province of the dyer, is to
obtain the colour in a state of solution, so as to allow the fibre to absorb it, and to
produce chemical combination, or to get the dye or colour in such a minute state of
division as it will penetrate or enter into the fibre of the stuff. These preparations
embrace the formation of decoctions, extracts, and solutions, and also in some cases of
precipitation, previous to immersing the stuff into the bath. Stu£^ chemically
considered, have but a feeble attraction for other matters, so as to combine with them
chemically; still that they do possess certain attractions is evident from varions
phenomena observed in the dyeing processes, and that this attraction is possessed
with different degrees of intensity by the different fibres, is also evident from the ease
and permanence that woollen stuff will take up and retain dyes compared with
cotton ; and also, that certain dyes are retained and fixed within or upon one kind of
fibre and not at all in another. This may be determined by plunging the dry staff
into solutions of the salts, and determining the density of the solution before the
immersion and after withdrawing the stuff. Wool abstracts alum from its solution,
but it gives it all out again to boiling water. The sulphates of iron, copper, and
zinc, resemble alum in this respect Silk steeped for some time in a solution of
protosulphate of iron, abstracts the oxide, and gets thereby dyed, and leaves the
solution acidulous. Cotton in nitrate of iron produces the same effect. Wool put in
contact with cream of tartar, decomposes a portion of it ; it absorbs the acid within its
pores, and leaves a neutral salt in solution in the liquor. Ck>tton produces no such
, effect with tartar, showing by these different effects that there are certain attractions
between the stuff and dyes. This attraction, however, may be more what is termed
a catalytic influence, the fibres of the stuff producing a chemioil action with ihe salt
or dye, with which it is in contact This attraction or affinity of the fibre for the
dye-drug, does not produce a very extensive effect in the processes of dyeing. More
probably the power of imbibing and retaining colours possessed by the fibre is more
dependent upon a mechanical than a chemical influence.
All dye-drugs must in the first instance be brought into a state of solution, in order
that the dye may be imbibed by the fibre ; but if the fibre exerts no attraction for the
colour so as to retain it, it is evident that so long as it remains capable of dissolving
in water, the stuffs being brought into contact with water, will soon lose their colour.
A colour thus fonhed does not constitute a dye, however strongly stained the stuffs
may appear to be, in or out the dyeing solution; in order to form a dye, the colour
must be fixed upon or within the stuff, in a condition insoluble in water. Hence
the mere immersion of the stuff into a solution of a colour will not constitute a dye,
except where the stuff really has an attraction for the colour and retuns it, or causes
a decomposition by which an insoluble compound is fixed upon it, such as referred to
by potting stuffs into solutions of iron. The abstraction of the colour fh>m a solution
by the immersion of the stuff, is often the result of a mechanical attraction possessed
by porous substances, enabling them to absorb or imbibe certain colouring matters
from solutions that are held by a weak attraction by their solvents. On this principle,
a decoction of cochineal, logwood, brazil-wood, or a solution of sulphate of indigo,
by digestion with powdered bone black, lose their colour, in consequence of the
colouring particles combining by a kind of capillary attraction with the porous carbon,
without undergoing any change. The same thing happens when well scoured wool
is steeped in such coloured liquids; and the colour which the wool assumes by its
attraction for the dye, is, with regard to most of the above coloured solutions, but
feeble and fugitive, since the dye may be again abstracted by copious washing with
DYEING. 65
simple water, whose attraetive force therefore OYercomea that of the wool. The aid
of a high temperature, indeed, is requisite for the abstraction of the colour from the
wool and the bone-black, probably by enlarging the sise of the pores, and increasing
the soWent power of the water.
Those dyes, whose colouring matter is of the nature of extractive, form a fiister
combination with stuffs. Thus the yellow, fawn, and brown dyes, which contain
tannin and extractive, become oxygenated by contact of air, and insoluble in water ;
by which means they can impart a durable dye. When wool \b impregnated with
decoctions of that kind, its pores get charged by capillurity, and when the liquid
becomes oxygenated, they remain filled with a colour now become insoluble in water.
The fixation of iron oxide and scTeral other bases also depends on the same change
within the pores or fibre, hence all salts that have a tendency to pass readily into the
basic state are peculiarly adapted to act as a medium for fixing dyes ; however, this
property is not essential.
hx onier to impart to the stuffs the power of fixing the colour in an insoluble form
upon it, recourse is had to other substances, which will combine with the soluble and
form with it an insoluble colour ; and it is not necessary that this new substance
should haTC an attraction for the stuff, or be capable of passing into a basic form, any
more than the original colour, but it is necessary that it be rendered insoluble while
in contact with the stuff.
Such substances used to unite the colour with the stuff hare been termed mordants,
which meant that they had a mutual attraction for the stuff and colour, and combining
with the stuff first, they afterwards took up the colour ; but this is only so in some
instances. A few examples will illustrate the bearing of these mordants. If a piece
of cotton stuff is put into a decoction of logwood, it will get stained of a depth accor-
ding to the colour of the solution, but this stain or colour may be washed from the
cotton hj putting it into pure water, the colour being soluble. If another piece of
cotton stuff be put into a solution of protosulphate of iron, and then washed from this,
a portion ot the iron will have undergone oxidation, and left the acid, and become
fixed upon the fibre and insoluble in water. Whether this oxidation is the result of
an influence of the stuff, or the effect of the oxygen of the air and water in which the
goods are exposed, it does not matter meantime, only this fixed oxide constitutes an
example of a mordant by its combining with the stuff. If this stuff is now put into
a decoction of logwood, the colouring matter of the logwood will combine with the
oxide of iron fixed upon the fibre, and form an insoluble colour, which after washing
will not remoTC from the stuff. If, instead of washing the stuff from the sulphate of
iron solution in water, it be passed through an alkaline lye of soda or potash, the
acid hblding the iron in solution is taken hold of by the alkali, and removed. The
oxide of iron is thus left upon the stuff, in a much larger quantity than in the
former case, and as firmly fixed, although not by any attraction between it and the
fibre, but simply being left within it. And this stuff being now put into the logwood
liquor, will form a dye of a depth according to. the quantity of iron thus fixed upon
the stuff, and equally permanent with that which had been fixed on the stuff by the
oxidation in working.
Such then are the methods of fixing within the stuff insoluble colours from soluble
compounds, and from these remarks the necessity of having the dye in solution will
also be erident
Suppose again that the sulphate of iron be mixed with the logwood decoction, there
will be produced the same colour or .dye as an insoluble precipitate : if the cotton
stuff is put into this, no colour worthy of the name of a dye will be obtained, as the
cotton wUl not imbibe within its fibre this precipitate. Place woollen stuff in the same
liquid, there is formed a very good dye» the woollen fibre having imbibed a great por-
tion odT the solid precipitate, probably owing to woollen fibres bein^ much larger than
those of cotton. Thus, with cotton and other stuff that will not imbibe freely solid pre-
cipitates, the mordant must be fixed within the fibre previous to applying the colouring
substances, such as the vegetable decoctions. It will also be seen that the dye which
is the product of combination between the mordant and colour is not that of the natural
colour of the drug, but the colour of the compound. Hence the great variety of tints
capable of being produced from one dye-drug, by varying either the kind or intensity
of the mordanL So that in the above instances, it is not the colour of the hematoxylin
fixed on the stuff, but its compound with iron, or tin, or alumina, as the case may be,
all of which give different tints.
It is upon this principle of rendering bases insoluble while within the fibre by
chemical means, that has brought to the use of the dyer a great number of mineral
dyes which in themselves, whether separate or combined, have no attraction whatever
for the fibre ; such as solutions of sulphate of copper, and yellow prussiate of potash,
nitrate of lead, and bichromate of potash, &c Suppose the stuff to be dyed a yellow
Vol II. • F
66 DYEING.
by the two last named salts, was first put into the solution of lead and then washed
previous to being put into the bichromate solution, the greater portion of the lead
would be dissoly^ Arom the stuff, and a very weak colour would be obtained. If the
stuff from the lead solution was put directly into the bichromate solution, a Tery good
dye would be the result ; but the portion of the solution remaining upon the suHSm^c of
the stuff will combine with the chrome and form a precipitate which the fibre cannot
imbibe, but will form an external crust or pigment upon the surfiice, which blocks up
the pores, and exhausts to no purpose the dye, causing great waste : hence the stuff
from the solution of lead is put into water containing a little soda or lime, and the
lead is thus reduced to an insoluble oxide within the fibre. The goods may now be
washed from any loose oxide adhering, and then passed through the bichromate
solution, when the chromic acid combines with the ozideof lead, forming a permanent
yellow dye. Thus it will be seen that whether the combination of the colour with
the stuff be chemical or mechanical the production of the dye which is fixed upon the
fibre is certainly a chemical question, anid the dyer should be familiar with the natnre
and principles of these reactions.
There are a few instances where the dye produced docs not come within the sphere
of these principles, there being no mordants required, nor any combination of the
colour formed within the stuff, but the dye-drug in its natural hue is fixed within the
fibre. Such colours^iave been termed substantive^ to distinguish them from those pro-
duced by means of mordants, which are termed adjective. Amongst this class of dyes
and dye-drugs stands pre-eminent indigo blue. Indigo in its natural state is entirely
insoluble in water, and is of a deep blue colour. The composition of this blue indi^
is represented as —
Carbon - - - 16 | Nitrogen - - I
Hydrogen - • 5 | Oxygen - » - 2
But it is found capable of parting with a portion of the oxygen, and by so doiog,
losing entirely its blue colour ; and in this deoxidised condition it is soluble in alkaline
lyes and lime water ; this colourless compound is termed indigogene. The opinion
of Liebig upon the constitution of this substance is, that indigo contains a salt radical,
which he terms Ani/le^ composed of 0"H*N. He considers that indigogene or white
indigo is the kydrated protoxide of this radical, and that blue indigo is the peroxide,
represented thus —
C H N O Water.
Salt radical, anyle - - -16 5100
Indigogene - - - -16 5111
Blue indigo - - - -16 5120
«
Advantage is taken of this property of indigo, of parting with its oxygen and becom-
ing soluble, to appl^ it to dyeing, and it is effected by the following means, when for
the purpose of dyemg vegetable stuff, as cotton ; and fi-om the circumstance of these
operations being done cold, the method is termed the cold vat, which is made up as
follows: — The indigo is reduced to an impalpable pulp, by being ground in water to the
consistence of thick cream. This is put into a suitable vessel filled with water, along
with a quantity of copperas, and newly slaked lime, and the whole well mixed by
stirring. After a short time the indigo is deoxidised and rendered soluble by a por-
tion of the lime which is added in excess, the reaction being represented thus :
1. Indigo, composed of [Jj5^^|^«®°*; ; • 7 Dyeing Solution.
{Protoxide of Iron • ^ — ^ .. ._
Sulphuric Acid .
^ ,. fj^;™« / "^ Cr^' Sulphate of Lime.
3. Lime- - - JLime. .... ^-f- -=^ Sulphate of Lime.
The peroxide of iron and sulphate of lime are precipitated to the bottom, and the indi-
gogene and lime form a solution of a siraw colour, with dark veins through it
The operation of dyeing by this solution is simply immersion, technically, dipping.
The stuff by immersion imbibes the solution, and when taken out and exposed to
the air, the indigogene upon and within the fibre rapidly takes oxygen fh)m the atmo-
sphere, and becomes indigo blue, thus forming a permanent dye, without any
necessary attraction between the indigo and the stuff.
ITie indigo vat for wool and silk is made up with indigo pulp, potash, madder, and
DYEING. 67
tmD. In tbis vat the extracts of madder and bran perform tbe deoxidising functions
of tbe copperas in tbe cold vat, by undergoing a species of fermentation.
Pastel and wood, eitber alone or witb tbe addition of a little indigo, is also used for
the dyeing of wool and silk stuff, tbe deoxidation being effected by tbe addition of
bran, msdder and weld. In dyeing witb tbese vats, tbe liquor is made warm, and they
require mucb skill and experience to* manage, in consequence of their complexity,
being always liable to go out of condition, as the dyeing goes on, by tbe extraction of
tbe indigogene and tbe modification of the fermentable matter employed to deoxidise
tbe indigo to supply that loss. The alkaline solvent also undergoes change, so there
must be snecessiTe additions of indigo and alkali ; tbe principal attention of the
dyer is tbe maintaining tbe proper relation of these matters, as too much or too little
of either is iiijarions.
Sulphate of indigo forms an intense blue solution, unaffected also by mordants.
Vegetable stuffs dipped in this retain no dye, for the washing off the acid in order to
preseire the fibre removes tbe colour ; but animal fibre, such as woollen and silk,
becomea dyed ; a portion of tbe blue remains upon the stuff after washing off the acid,
being retained by capillary attraction. This dye is termed Saxon blue, but it has very
little of tbe permanence of indigo or vat blue^ although it is also a substantive colour.
Another truly substantive colour is that dyed by cartbamus or safflower, but the
fixation of tbis dye npon'tbe stuff differs from any of those referred to. Like indigo,
it has no affinity for any base or substance capable of forming a mordant ; its solvent
is an alkali, but in this dissolved state it does not form a dye. Tbe mode of
proeeedinp; in dyeing witb cartbamus is first to extract the dye from the vegetable
in whicb it is found, by soda or potash, which is afterwards neutralised by an acid
previous to dyeing, whicb renders the colour insoluble, but in so fine a state of division
that no precipitation can be seen for some time and the stuff immersed in this imbibes
the colour within its fibre, its lightness assisting tbis action, as the precipitate will
remain suspended in water for days before it will subside. Vegetable fibre takes up
tbis dye as easUy as animal, but whether by an attraction for tbe stuff, or by a
mechanical capillary attraction of the fibre is not so easily determined. A piece of
stuff suspended in a vessel filled witb water, having in it some insoluble carthamine,
all tbe colouring particles will flow to and combine witb the fibre from a considerable
distance, giving a proof of tbe existence of some force drawing them together.
Such then are tbe various conditions and principles involved in the processes of
fixing tbe dye within or upon tbe stuff.
During the operations of dyeing there are certain circumstances which have to be
attended to^ in order to fiicilitate and effect certain hues or tints of colour. Thus,
witb many of the colouring substances, beat not only favours but is necessary for
the solution of tbe dye, and also its combination witb tbe stuff or mordant Decoctions
of woods are always made by hot water, and the dyeing processes with decoctions are
in bot liquor. When the colouring matter of quercitron bark is extracted by boiling
water, tbe colour produced upon tbe stuff wUl be a rich amber yellow, but if tbe
extract be made by water at 180^ Fabr., a beautiful lemon yellow will be the dye pro-
duced by it, unng tbe same mordant in each case. Colours dyed by madder and
Barwood must be done at a boiling beat during the whole process, or no dye is effected.
Sumach, another astringent substance, is most advantageously applied at a boiling
heat; and in order to have a large body of this dye fixed upon the stuff, it should be
immersed in the liquor while hot and allowed to cool together, during which the
tannin of tbe dye undergoes some remarkable change in contact witb the stuff.
Sai&ower dyes are kept cold, so are tin bases, Prussian blues, and chrome yellows : by
applying heat to the last a similar result is effected to that witb bark; instead of a
lemon yellow an amber yellow will be obtained. Almost all colours are affected less
or more by tbe temperature at which they are produced. Some mordants are fixed
upon the stuff by beat, such as acetate of alumina; the stuff being dried from a solution
of this salt at a high temperature loses part of tbe acid by being volatilised, and there
remains upon tbe fibre an insoluble suboxide, which fixes tbe dye. These remarks
respecting tbe methods apply more particularly to vegetable stuffs, as cotton, and in
many cases also to silk, but wool is always dyed at a high beat Although wopl
seems to have a mucb ^ater absorbing power than cotton, the latter will absorb and
become strongly dyed m a cold dye bath, in which wool would not be affected ; but
apply heat and (he wool will be deeply dyed, and the dye mucb more permanent than
the eotton.
The permanence of colours is another property to be carefully studied by tbe
practical dyer, as the colour must not be brought under circumstances that will
destroy its permanency during any of the operations of the dyebouse. The word
permanent, however, does not mean fast^ which is a technical term applied to a colour
that will resist all ordinary operations of destruction. As for instance, a Prussian
68 DYEING.
blue U a pemianeDt colour but not a fast coloar, as any alkaline matter will destroy
it, or a common black is permanent, although any acid matters trill destroy it ;
while Turkey red is a fast colour and not affected by either acid or alkaline matters.
A few of the circumstances affecting colours in the processes they are subjected to may
be referred to in this place. If, for instance, the air in drying the dyed stuff in a
hot chamber be moist, there is a great tendency to the colour being impaired in
these circumstances. For example, a red colour dyed with safflower will pass into
brown, a Prussian blue will pass into a grey lavender, chrome yellows take an amber
tint Mostly all colours are affected less or more by being subjected to strong heat
and moisture; even some of those colours termed fast are affected under sach
circumstances. A dry iieat has little or no effect upon any colour, and a few colours
are made brighter in their tint by such a heat, as chrome orange, indigo blue, on
cotton, &c.
Some of these effects of heat and moisture differ with different stuff; thus indigo
blue upon cotton is not so much affected as indigo blue upon silk, while safflower red
upon cotton will be completely destroyed before the same colour upon silk will be
perceptibly affected. The same colouring matter fixed by different mordants upon
the same stuff is also differently affected under these conditions.
Light is another agent effecting a great influence upon the permanence of colours,
which should be also considered by the dyer. Reds dye^ by a Braxil wood and a
tin mordant, exposed to the light, become brown ; Prussian blue takes a purple tint ;
yellow becomes brownish ; safflower red, yellowish, and these changes are facilitated
by the presence of moisture ; such as exposing them to strong light while drying from
the dye bath, either out or within doors. The direct rays of the sun destroy all
dyed colours ; even Turkey red yields before that agency.
Boiling was formerly prescribed in France as a test of fast dyes. It consisted in
putting a sample of the dyed goods in boiling water, holding in solution a determinate
quantity of alimi, tartar, soap, and vinegar, &c Dufay improved that barbarous test
He considered that fast*dyed cloth could be recognised by resisting an exposure of
twelve hours to the sunshine of summer, and to the midnight dews; or of sixteen da js
in winter.
In trying the stability of dyes, we may offer the following rules : —
That every stuff should be exposed to the light and air ; if it be intended to be
worn abroad, it should be exposed also to the wind and rain ; that carpets moreover
should be subjected to friction and pulling, to prove their tenacity ; and that cloths
to be washed should be exposed to the action of hot water and soap. However, such
tests are not at all applicable to most of the colours dyed upon cotton stuff. Not
many of them can stand the action of hot water and soap, or even such acids as the
juice of fruits. Indigo blue, one of the most permanent dyes on cotton, yields its
intensity to every operation of washing, even in pure water.
DelavaFs observations on the nature of dyes may be thus summed up. In tran-
sparent coloured substances, the colouring substance does not reflect any light ; and
when, by intercepting the light which was transmitted, it is hindered fVom passing
through substances, they do not vary from their former colour to any other colour,
but become entirely black ; and he instances a considerable number of coloured
liquors, none of them endued with reflective powers, which, when seen by transmitted
light, appeared severally in their true colours ; but all of them, when seen by incident
light, appeared black ; which is also the case of black cherries, black currants, black
berries, &c., the juices of which appeared red when spread on a white ground, or
otherwise viewed by transmitted instead of incident light ; and he concludes, that
bleached linen, 8cc "when dyed with vegetable colours, do not differ in their
manner of acting on the rays of light, from natural vegetable bodies ; both yielding
their colours by transmitting, through the transparent coloured matter, the light which
is reflected from the white grobnd : " it being apparent, from different experiments,
" that no reflecting power resides in any of their components, except in their white
matter only," and that "transparent coloured substances, placed in situations by which
transmission of light through them is intercepted, exhibit no colour, but become
entirely black."
The art of dyeing, therefore (according to Mr. Delaval), " consists principally in
covering white substances, from which light is strongly reflected, with transparent
coloured media, which, according to their several colours, transmit more or less
copiously the rays reflected from the white,*' since " the transparent media them-
selves reflect no light ; and it is evident that if they yielded their colours by reflect-
ing instead of transmitting the rays, the whiteness or colour of the ground on
which they are applied would not in anywise alter or affect the colours which they
exhibit"
But when any opaque basis is interposed, the reflection is doubtless made by it,
. DYEING. 69
rather than by the substance of the dyed wool, silk, fte., and more especially when
such basis consists of the white earth of alum, or the white oxide of tin § which, by
their strong reflective powers, greatly augment the lustre of colours. There are,
moreover, some opaque colouring matters, particularly the acetous, and other solu-
tions of iron, used to stain linen, cotton, &c., which must necessarily themselves
reflect instead of transmitting the light by which their colours are made perceptible.
The compound or mixed colours are such as result from the combination of two
differently coloured dye stuffs, or from dyeing stuffs with one colour, and then with
another. The simple colours of the dyer are red, yellow, blue, and black, with which,
when skilfully blended, ho can produce every variety of tint Perhaps the dun or
fawn colour might be added to the above, as it is directly obtained from a great many
vegetable substances.
1. Bed with yellow, produces orange; a colour, which upon wool is given usually
with the spent scarlet bath. To this shade may be referred flame colour, pome-
granate, capuchin, prawn, jonquil, ctusis, chamois, cq/if au lait^ aurora, marigold,
orange peel, mordores, cinnamon, gold, &c. Snuff, chestnut, musk, and other shades
are produced by substituting walnut peels or sumach for bright yellow. If a little blue
be added to orange, an olive is obtained. The only direct orange dyes are annotto,
and subchromate of lead. See Silk and Wool Dteino.
The latter is never used for dyeing orange upon silk and wool, while the former is
now never used for cotton. An orange with annotto is very fugitive, even uiton the
animal fibre ; but much more so upon cotton. Subchromate of lead is produced upon
cotton by dyeing it first a deep chrome yellow by acetate of lead and bichromate of
potash, as already noticed, and then passing the stuff so dyed through a hot solution
of an alkali or lime, which changes the dye from the yellow chromate to the state of
subchromate, which is deep orange.
2. Red with blue produces purple, violet, lilac, pigeon's neck, mallow, peach-
blossorm, iUu de rot, lint-blossom, amaranth.
' Thus a Prassian blue dyed over a safflower red, or vice versa, wUl produce any of
these tints by varying the depth of the red and blue according to the shade required ;
but the same shades can be produced direct by logwood and an aluminous or tin
mordant; the stuff being steeped in sumach liquor previous to applying the tin
mordant produces the reddish or purple tint when such is required.
3. Bed with black ; brown, chocolate, maroon, &c. These tints are produced by
various processes. To dye a deep orange by annotto liquor, and then form over it a
black by sumach and sulphate of iron, gives a brown ; or dye the stuff first a rich
yellow by quercitron and a tin mordant, and then over the yellow produce a purple by
passing it through logwood ; chocolates are thus produced. A little Brazil wood with the
logwood gives more of the red element AYhen maroon is required, the red is made
to prevail, and so by a judicious mixture, these various tints are produced. Brown,
especially upon cotton fibre, is more often produced direct by means of catechu.
Steep the stuff in a hot solution of catechu, in which the gummy principle has been
destroyed by the addition of a salt of copper ; then pass through a solution of bichro-
mate of potash at boiling heat, when a rich brown is obtained.
4. Yellow with blue ; green of a great variety of shades ; such as nascent green, gay
green, grass green, spring green, laurel green, sea green, celadon green, parrot green,
cabbage green, apple green, duck green.
Green is essentially a mixed dye, and produced by dyeing a blue over a yellow or
It yellow over a blue. In almost all cases the blue is dyed first, and then the yellow, and
according to the depth of each or any of these are the various tints of green produced.
With silk and wool, one kind of green dye may be produced simultaneously by
putting sulphate of indigo into the yellow dye bath, and then working the previously
prepared or mordanted stuff in this. With cotton, an arsenite of copper (Scheele*s
green) may be produced by working the stuff in a solution of arsenite of potash or
soda, and then in sulphate of copper, which produces a peculiar tint of green.
5. Mixtures of colours, three and three, and four and four, produce an indefinite
diversity of tints : thus, red, yellow, and blue form brown olives and greenish greys;
in which the blue dye ought always to be first given, lest the indigo vat should be
soiled by other colours, or the other colours spoiled by the alkaline action of the vat.
Red, yellow, and grey Cwhich is a gradation of black) give the dead-leaf tint, as well
as dark orange, snuff colour, &c. Red, blue and grey give a vast variety of shades ;
as lead grey, date grey, wood-pigeon grey, and other colours too numerous to
specify. See Brown Dye.
Care must be taken, however, in mixing these colours, to study the depth of the
tint required ; as, for instance, were we wishing to dye a slate grey, and to proceed
first by dyeing a blue, then a red, with a little of the grey, we would produce, instead
of a slate grey, a purple or peach. The arrangement referred to, applies only to the.
f3
70 EBULLITION.
elements of the coloan that enter into the composition of the varioos tints, so that a
slate grey is^a blae with a small portion of red, and a still smaller portion of Uie black
element, that produces the grey tint Thus, dye the staff first a deep sky bine by the
Tat, then by passing through a solution of sumach, with a small quantity of logwood,
Brazil wood, copperas, and alum, grey will be produced. The Brasil wood gives the
red tint, sumach and copperas the black tint, the logwood assisting in this, and with tlie
aid of the alum throwing in the puce or dore neck hue ; and thus by the Tariatioo of
these hues by such arrangements, any of the grey tints can be produced. See Cauco
Peintino.
DYER'S ALKANET, Alkanna tinctoria. See Alkanet.
DYER'S MADDER, Bubia tinctorium. See Madder.
DYER'S OAK, Qttercus infectoria. See Galls and Oak.
DYER'S ORCHELLA WEED, RocceUa tinctoria. See Archil, Obchella.
DYER'S SAFFLOWER, or Bastard saffron. The Carthamus tinctorius. The
flowers are of a deep orange colour, but they are used for dyeing various shades of
red. The flowers of the carthamus are employed in Spain for colouring dishes and
confectionery. See Safflower.
DYER'S WOODROOF. Asperula tinctoria. The roots of this plant are used in
some parts of Europe, particularly Dalmatia, instead of madder, for dyeing wool and
cloth of a reddish colour ; but in bulk the crop obtained is inferior to that of the
madder. — .Lawwn,
E.
EARTHS. (TVrref, Fr. ; Erden, Germ.) It has been demonstrated that the sob-
stances called Earths, and which, prior to the electro-chemical career of Davy, were
deemed to be elementary bodies, are all compounds of certain metallic bases and
oxygen. Five of the earths, when pure, possess decided alkaline properties, being
more or less soluble in water, having (at least three of them) an acrid alkaline taste,
changing the purple infhsion of red cabbage to green, most readily saturating the
acids, and affording thereby neutro-saline crystals ; these are baryta^ Mtrontici^ Ume
(calcia\ magneaiay and litkia. The earths proper are alumina,, gludna^ yttritt^ zireomia,
and thorina; these do not change the colour of infusion of cabbage or tincture of
litmus, do not readily neutralise acidity, and are quite insoluble in water.
EARTHY COBALT. See Wad. A manganese ore, in which the oxide of cohalt
sometimes amounts to thirty-three per cent — Dana,
EARTHY MANGANESE. See Wad and Manoakbse.
EAST INDIA' BLACK WOOD. The Sit Sal of the natiTes of India. The Dal-
bergia iati/olia. It is a wood of a greenish black colour, with light coloured Teins. It
takes a fine polish, and is very heavy.
EAU DE COLOGNE. See Perfuuert.
EAU DE LUCE. See Perfcmert.
EBONY. Of this black wood three kinds are imported:--
The Mauritius Ebony, which is the blackest and finest grain.
The East Indian Ebony, which is not of so good a colour.
The African Ebony, which is porous and bad in point of colour.
The ebony of the Mauritius is yielded by the Diospyrua Ebenus, Colonel Uoyd
says, this ebony when first cut is beautifully sound, but that it splits like all other
woods from neglectful exposure to the sun. The workmen who use it immerse it in
water as soon as it is felled for from six to eighteen months ; it is then taken out, and
the two ends are secured fh)m splitting by iron rings and wedges. Colonel Lloyd
considers that next to the Mauritius, the ebony of Madagascar is the best, and next
that of Ceylon.
The Mauritius ebony is imported in round sticks like scaffold poles, about fourteen
inches in diameter. The East Indian variety comes to us in logs as large as twenty-
eight inches diameter, and also in planks. The Cape of Good Hope ebony arrives in
England in billets, and is called billet wood, about from three to six feet long, and two
to four inches thick.
The uses of ebony are well known.
White Ebony comes from the Isle of France, and is much like box wood. See
Green Ebont.
EBULLITION. (Eng. and Fr. ; Kochen, Germ.) EoUing. When the bottom of
an open vessel containing water is exposed to heat, the lowest stratum of finid imme-
diately expands, liecomes therefore specifically lighter, and rises through the colder
and heavier particles. The heat is in this way diffused through the whole liquid
EBULLITION.
11
mass, not by simple eommimicatioiiof that power from particle to particle as in solids,
— called the amductioH of caloric,— bat bj a translation of the several particles from
the bottom to the top, and the top to the bottom, in regular succession. This is deno-
minated the carrying powers of fluids, being common to both liquid and easeons bodies.
These internal moTements may be rendered very conspicuous and instructive, by
mingling a little powdered amber with water, contained in a tall glass cylinder, stand-
ing upon a sand-bath. That this -molecular translation or locomotion is almost the
sole mode in which fluids get heated, may be demonstrated by placing the middle of a
pretty long glass tube, nearly filled with water, obliquely over an argand flame. The
upper half of the liquid will soon boil, but the portion under the middle will continue
cool, so that a lump of ice may remain for a considerable time at the bottomv When
the heat is rapidly applied, Uie liquid is thrown into agitation, in consequence of
elastic vapour being suddenly generated at the bottom of the Tessel, and being as
suddenly condensed at a little distance above it by the surrounding cold column.
These alternate expansions and contractions of Tolume become more manifest as the
liquid becomes hotter, and constitute the simmering, vibratory sound which is the
prelude of ebullition. The whole mass being now heated to a pitch compatible with
its permanent elasticity, becomes turbulent and explosive under the continued in-
fluence of fire, and emitting more or less copious volumes of vapour, is said to boiL
The further elevation of temperature, by the influence of caloric, becomes impossible
in these circumstances with almost all liquids, because the vapour carries off from
them as much heat in a latent state as they are capable of receiving from the fire.
The temperature at which liquids boil in the open ur varies with the degree of
atmospheric pressure, being higher as that is increased, and lower as it is diminished.
Hence boUing water is colder by some degrees in an elevated situation, with a de-
pressed barometer, tiian at the bottom of a coal-pit in fine weather, or, when the
barometer is elevated. A high column of liquid also, by resisting the discharge of
the steam, raises the boiling point As we ascend from the sea level, the boiling point
becomes lower, the following table illustrates this.
Yudi Inches of Boiling
high. pretture. point.
Farm of Antisana - - 4488 17'87 187-34
Quito - - - - 3170 20-74 194*18
Mexico .... 2490 22-52 198*14
StGothard - - - 2302 2802 199*22
Brianfon - - - - 1423 25*39 203*9
Monte Doie - - - 1136 26*26 205*7
Madrid - - . - 665 27*72 208*04
Moscow - . - - 328 28*82 210*2
Lyons . . - - 177 29*33 210*92
Paris .... 71 2969 211*46
Nichol.
In vaetiOf all liquids boil at a temperature about 124° F. lower than under the
average atmospheric pressure. For a table of elasticities, see Vapoub. Gay-Lassac
has shown that liquids are converted into vapours more readily, or with less turbu-
lence, when they are in contact with angular or irregular, than with smooth surfaces ;
that they therefore boil at a heat 2^ F. lower in metallic than in glass vessels, pro-
bably owing to the greater polish of the latter. For example, if into water about to
boil in a glass matrass, iron filing ground glass, or any other insoluble powder be
thrown, such a brisk ebullition will he instantly determined, as will sometimes throw
the water out of the vessel ; the temperature at the same time sinking two degrees F.
The following table exldbits the boiling heat, by Fahrenheit's scale, of the most
important liquidi : —
Ether • Graham ... 96**
Ether, specific gravity 0*7365 at 48° 100
Carburet of sulphur -.-....-..113
do. ------ . Graham - - - 118
Alcohol, sp. grav. 0*813 - . - - - lire - - - - 173*5
Nitric acid, do. 1*500 .... - Dalton ... 210
da do. 1*42 Graham - - - 248
Water 212
Saturated solution of Glauber salt . . - Biot - - - - 213|
do. do. Acetate of lead - - do. - - - - 21 5|
do da Sea salt .... do. ---- 224}
do da Muriate of lime - - Ure - - " - 285
da do. do. 1+ water 2 do. - » ** - 230
P4
72 EBULLITION ALCOHOLMETER.
Saturated Bolation of muriate of lime, 35-5 + water, 64-5 Ure ... ass**
Ammonia -- ..---- Graham - - 140
Crystallised chloride of calciam - - - - do. - - - S02
Saturated solution of muriate of lime, 40*5 + water, 59-5 Ure - - . 240
Muriatic acid, sp. grav^. 1-094 - - - - Dalton - - - 232
do. do. 1127 ... - do. - - - 222
Nitric acid, do. 1*420 . - - - da - - - 248
do. do. 1-30 - - - - do. - - - 236
Rectified petroleum ------ Ure - - - 306
Oil of turpentine - - - - - - do. - - - 316
Sulphuric acid, sp. grav. 1-848 - - - - Dalton - - - 60O
do. do. 1-810 - - - - do. - - - 473
do. do. 1-780 - - - - do. - ■ - - 435
do. do. 1-700 - - - - do. - - - 374
do. do. 1-650 - - - - do. - - - 350
do. do. 1-620 . - - - do. - - - 290
do. do. 1-408 - - - - do. - - - 260
do. do. 1-300 - - - - do. - - - 240
Phosphorus ------- do. - - - 554
Sulphur do. --- .'i70
Linseed oil ------- do. - . - 640
Whale oil Graham - - 630
Mercury Dulong - - - 662
do. -------- Crighton - - 656
Saturated solution of acetate soda, containing 60 per cent . Griffiths - - 256
do. Nitrate of soda, 60 do. - - - 246
do. Rocheliesalt, 90 do. • - - 240
do. Nitre, 74 do. - - - 238
do. Muriate of ammonia, 50 do. - - - 236
do. Tartrate of potash, 68 do. - - - 234
do. Muriate of soda, 30 do. - - - 224
do. Sulphate of magnesia, 57*5 do. - - - 222
do. Borax, 52-5 da - - - 222
do. Phosphate of soda, ? do. - - - 222
do. Carhonate of soda, 7 do. • - - 220
do. Alum, 52 do. - - - 220
do. Chlorate of potash, 40 do. - - - 218
do. Sulphate of copper, 45 do. - - - 216
•
EBULLITION ALCOHOLMETER. That the boiling temperature of water i«
increased by holding neutro-saline and saccharine substances in solution has been long
known, and has been the subject of many experiments, made partly with the Tiew of
ascertaining from that temperature the proportion of the salt or sugar, and partly with
the view of obtaining a practical liquid bath. But it seems to have been reserved for
the "Abbe Brossard-Vidal, of Toulon, to have discovered that the boiling temperature
of alcoholic liquors is, in most cases, proportional to the quantity of alcohol, im*spec-
tively of the quantity of neutro-saline or saccharine matter dissolved in them. When,
however, such a quantity of dry carbonate of potash, or sugar, is added to a spirituous
liquor as to abstract or fix in the solid state a portion of the water present, then the
boiling temperature oiTthat mixture will be lowered in proportion to the concentration
of the alcohol, instead of being raised, as would be the case with water so mixed.
But, generally speaking, it may be assumed as a fact, that the boiling point of an
alcoholic liquor is not altered by a moderate addition of saline, sacchai ine, or extrac-
tive matter. On this principle, M. Brossard-Vidal constructed the instrument repre-
sented in Jig. 684, for determining by tluit temperature the proportion of alcohol
present His chief object was to furnish the revenue b«mrds of France with a means
of estimating directly the proportion of alcohol in wines, so as to detect the too
common practice of introducing brandy into their cities and towns under the mask of
wine, and thereby committing a fraud upon the octroi; as the duty on spirits is much
higher than on wines.
'J'he above iostrument consists of a spirit-lamp, surmounted by a small boiler, into
which a large cylindric glass bulb is plunged, having an upright stem of such calibre
that the quicksilver contained may, by its expansion and ascent when heated, raise
before it a little glass float in the stem, which is connected by a thread with a similar
glass bead, that hangs in the air. The thread passes rouud a pulley, which turning
with the motion of the beads causes the index to move along the graduated circular
scale. The numbers on this scale represent per centages of absolute alcohol, so that
EBULUTION ALCOHOLMETER, 73
the nnmber oppodEe to vbich the index stops, vhcn the liquor in the cjUnder orer
the lamp bnili britkly. deaDles tbe per eeuu^e of ilcohol io it.
Dr. tire iiitcodiic«d oQolber form ofiiutnuaeDl (jSj. 895V It is thm deieribed Iiy
tlic inTeutor: —
0
It miuiats, I, of a flat apiril-tanip a, inrroaaded by a taaeer for rontiinioft
cold watfr to ke?p tlie liuop cool, should innny eiperimentB require la he mude in *iic-
ccsaion; S, of the boiler B. vhieb fits by it« bottom cnge c, upon the ciue of the
. lamp. At the point c. Is seen the edge of the damper-plate for modifying the flame
<,t the lamp, or eitinguiBhJng il wh«D the experiiueut is completed, c is the thermo-
meter, made with s Terj minute bore, in the manner of the Rev. Mr. Wollaslon'i in-
(LtrumeDt for measuring the height of a mountain by the boiling point of water OD it*
summiL The bottom nf the scale in the ebullitioa thermometer, is marked p for
proof OD the left tide, aod 100 (of proof spirit) on the rijrht side. It correspondi
to 1786 Fahr. very nearly, or the boiling point of alcohol of O'SaO specific gravity.
The following table gives the boiling poinla coirespoDding to the indie Hted densities i —
SpcclSc griTltr- Temp. Fi
178-6
179-75
IBO'4
ISI-0
18.1-4
0-9SO0
P.
185-6
0S.12I
10 U. P.
189-0
0-9420
ao „
liH-8
0-9S16
30 „
0-960
40 „
202-0
0-9665 SO U. P.
90
The above table is the mean of a great man; experiments. When alcohol is
stronger than 0 92, or the excise proof, its boillag point variea too little vitb Its
progressiTe increase of strength to rend^ that lest applicable in practice. In fact,
even for proof spirits, or spirits approaching in strength 10 proof, a more exact
indication may be obtained by dilulinj: them with their own bulk of water, before
ascertaining their strength and then doubling it.
The boiling point of any alcoholic liquor is apt to rise if the heal be long continued,
and thereby to lead into error in using this instrument. This source of fallacj maj
be. io a fcreat roeainre avoided by adding to the liquor iii the little boiler about a
teaapooDfal (thiny-fiTc grains) of common enlinary talt, whicli haj! the curious eCEect
of arresting the mcrcary in the Ihcnaomcter at the true boiling point of the spirit.
71 EBULLITION ALCOHOLMETEE.
wine, or beer, to enable a correct reading to be had. The small measure marked m
holds the requisite quantity of salt
The thermometer is at first adjusted to an atmospheric pressure of 29*5 inches.
When that pressure is higher or lower, both water and alcohol boil at a somewhat
higher or lower temperatare. In order to correct the error which would hence
arise in the indications of this instrument under different states of the weather,
a barometrical equation is ftttachod, by means of the subsidiary scale e, to the ther-
mometer x>.
Having stated the principles and the construction of the ebullition of the alcohol-
meter, I shall now describe the mode of its application.
First — ^Light the spirit lamp a.
Second. — Charge the boiling vessel b, with the liquid to be tested (to within an
inch of the top), introducing at the same time a paper of the powder ; then place the
vessel B (the damper plate being withdrawn) on to the lamp a«
Third. — Fix the thermometer d on the stem attached to b, with its bnlb immersed
in the liquid. The process will then be in operation.
The barometrical scale indicated on the thermometer is opposite the mean boiling
point of water. Prior to commencing operations for the day, charge ^the boiler b
with water only, and fix the instrument as directed ; when the water boils fireely, the
mercury will become stationary in the stem of the thermometer, opposite to the true
barometrical indication at the time. Should the mercury stand at the line 29-5 this
will be the height of the barometer, and no correction will be required ; but should
it stand at any other line, above or below, then the various boiling poiBts will bear
reference to that boiling point.
In testing spirituous or fermented liquors of any kind, when the mercnry begins
to rise out of the bulb of the thermometer into the stem, push the damper-plate half-
way in its groove to moderate the heat of the flame. When the liquor boils freely
the mercnry will become stationary in the stem ; and opposite to its indication, on the
left, the underproof percentage of spirit may be read off at once, if the barometer
stand that day at 29 '5 inches; while on the right hand scale, the percentage of
proof spirit is shown; being the difference of the former number from 100. The
damper-plate is to be immediately pushed home to extinguish the flame.
The alcoholmeter will by itself only indicate the percentage of alcohol contained
in any wine, but by the aid of the hydrometer, the proportionate quantity of sac-
charum in all wines may be readily and easily determined. The hydrometer will
show the specific gravity of the liquid upon reference to table Na I, annexed. In
testing a sample of wine, first take the specific gravity, and suppose it to be 989,
then charge the boiler of the alcoholmeter with the wine, as directed, and at the
boiling point it indicates the presence of alcohol at 69*6 per cent**'', whose specific
gravity will be found to be 979 ; deduct that gravity f^om the gravity of the bulk,
or 989, and 10 will remsfln, which 10 degrees of gravity, upon reference to the wine
table, will be found to represent 25 lbs. of saccharine or extractive matter in every
1 00 gallons, combined with SO^th gallons of proof spirit
Sikes*s hydrometer will only show the sp. gr. of liquids lighter than water (or
1000), and for wines in general use, the gravities being lighter than that article, will
answer every purpose ; but there are wines whose gravities are heavier than water,
such as mountain, tent, rich Malagas, lachrymas Christi, &c., to embrace which
additional weights to the hydrometer will be required, as for cordialised spirits, &c.
In testing a sample of rich mountain, its sp. gr. was found to be 1039, or 39 degrees
heavier than water ; that wine at the boiling point indicated the alcohol 72'5 per
cent"*p* ; but 980 sp.gr. deducted f^om 1039 leaves 39 degrees of sp.^.; against 59
of the wine tables will be found 147-5 or 147^ lbs. of saccharine or extractive
matter, combined with 27 1 gallons of proof spirit to every 100 gallons.
Should the barometer for the day show any other Indication above or below
the standard of 29*5, the thermometer scale will then only show the apparent strength,
and reference must be had to the small ivory indicator, e, it being the counterpart
of the barometrical scale of the thermometer; thus, should the barometer indicate
30, place 30 of the indicator against the boiling point of the liquid, and opposite the
line of 29*5 will be found the true strength. «
Exomple 1. — ^Barometer at 30. — Suppose the mercury to stop at the boiling-point
72"*»', place 30 of the indicator against 72 on the thermometer, and the line of 29*5
will cut 69 '6"'*, the true strength.
Example 2. — Barometer' at 29.~Suppose the mercury to stop at the same point,
72.«*p% place 29 of the indicator against 72 on the thermometer, and the line of 29*5
will cut 74*3-*'P', the true strength.
For nuUted liquors. — To all brewers and dealers in fermented liquors, this principle,
by its application, will supply a great desideratum, as it will not only show the alcohol
created in the wort by the attenuation, as well as the original weight of the wort prior
EBULLITION ALCOHOLMETEB.
75
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76
EBULLITION ALCOHOLMETER. '
No. 2.
TABLE, showing the lbs. of Sugar per Gallon in Cordialized Spirits, with Per
to be added to the indicated Strength, per the Alcobolmeter.
DlSbrence or
Gravity.
10
15
20
25
30
36
40
45
50
Diflerenoe of
Grarity.
Lbt. of Sagar
per Gallon.
4 ox.
or 85
to 100
6 ox.
to 100.
8 01.
SO
to 100.
10 OS.
to 100.
12 Of.
75
to 100.
14 01.
87*
to 100
l-O
7-1
oz.
1-8
ox.
1-4
IJm. ofSttgar
per Gallon.
Np. Orav.
orS|«lrlt.
920
Percent.
of SiiiriU
1-6
2-5
3-4
4-4
5-3
6*2
8-1
90
PorCOTt.
orSnirik
fjp. Gxmv.
923
2-5
1-6
2-5
3-3
4-3
5-2
6-1
6-9
7-8
8*8
2-5
923
926
5-
1-5
2-4
3-2
4-2
5-0
5-9
6-8
7-7
8-6
5-
926
929
7-5
1-5
2-3
3-2
4-1
4-9
5-8
6-6
7-5
8-4
7-5
929
932
10-
1-4
2-2
3 1
4 0
4-8
5-7
6-5
7-4
8-2
10-
932
935
12-5
1-4
2 '2
3-1
3-9
4-7
5-5
6-3
7-2
80
12-5
935
938
15-
1-4
21
SO
3-8
4-6
5-4
6-2
70
7-8
15-
938
940
17-5
1*3
21
2-9
3-7
4-5
5-3
60
6-8
7-6
17-5
940
943
20-
1-3
20
2-8
3-6
4.4
5-2
5 9
6-7
7-5
20*
943
945
22-5
1-3
20
2-7
3-5
4-3
50
5-7
6-5
7-3
22-5
945
948
25-
1-2
1-9
2-6
8-4
4-1
4-8
65
6-3
70
25-
948
950
27-5
1-2
1-9
2-5
3-3
40
4.7
5-3
6-1
6-8
27-5
950
952
30-
1-1
1-8
2-4
3-1
3-8
4-5
51
5-8
6-5
SO-
952
954
32-5
11
1-7
2-3
SO
S-6
4-3
4-8
5-5
6-2
32-5
954
956
35-
1-0
1*6
2-2
2-9
3-5
41
4-6
5-3
60
35-
956
958
37-5
lO
1-6
21
2-8
3-4
3-9
4.4
5-1
5-8
37-5
958
960
40-
•9
1-5
2-0
2-7
3-2
3-8
4-3
4-9
5-5
40*
960
962
42 5
•9
1-5
2-0
2-6
3-1
3-6
41
4-7
5-3
42-5
962
964
45-
•9
1-4
1-9
2-5
SO
3-5
4 0
4-6
5-1
45-
964
965
47-5
•8
1-4
1-9
2-4
2-9
3-4
3 9
4-4
4-9
47-5
965
967
50-
•8
1-3
1-8
2-3
2*8
3-3
3-8
4-3
4-8
50-
967
969
52-5
•7
1-2
1-7
2-2
2-6
31
3-6
4-1
4-5
52-5
969
970
55'
-7
1-2
1-6
2 0
2-4
2-9
3-4
3-8
4-2
55'
970
972
57-5
•6
M
1-5
1-9
2-2
2-7
31
3-5
3-9
57-5
972
973
60-
•6
lO
1-4
1-8
2-1
2-5
2-9
3-3
3-6
60'
973
974
62-5
•6
1-0
1-3
1-7
20
2-4
2-7
31
3-4
62 '5
974
976
65-
•5
•9
1*2
1-5
1-8
2-2
2-5
2-8
3' I
65-
976
977
67-5
•5
•8
M
1-4
1-7
20
2-3
2-6
2-9
67-5
977
979
70 •
•4
•7
1-0
1-3
1-5
1-8
21
2-4
2-6
70-
979
980
72-5
•4
•7
.9
11
1-3
1-6
1-9
21
2-3
72-5
980
982
75-
•3
•6
•8
1-0
1-2
1-4
1-6
1-8
20
75-
982
983
77-5
•3
S
•7
•9
10
1-2
1-4
1-6
1-8
77-5
983
984
80-
•2
•4
•6
•8
•9
10
1-2
1-4
1-6
80-
984
986
82 5
•2
•3
•5
•7
•8
•9
10
1-2
1-4
82-5
986
988
85-
•2
•2
•4
•6
•7
•8
•9
10
1-2
85-
988
990
87-5
•1
•2
•3
•5
•6
•7
•8
•9
10
87-5
990
992
90-
•1
•1
•2
•4
•5
•6
•7
•8
•9
90-
992
994
92-5
'-
•1
•2
•3
•4
•5
•6
•7
•8
92-5
994
996
95-
« m
.
•1
•2
•3
•4
5
•6
•7
95-
996
998
97-5
i
m *
•1
•2
•3
•4
•5
'6
97-5
998
1
to fermentatioD, but it will indicate the valae of malt liquors in relation to their com-
ponent parts. It will likewise be a ready means of testing the relative value of worts
from sugar compared with grain, as well as being a guide to the condition of stock
beers and ales.
To ascertain the strength of malt liquors and their respective values, the instrument
has been supplied with a glass saccharometer, testing-glass, and slide-rule. Commence
by charging the testing-glass with the liquid, then insert the saccharometer, to ascertain
its present g^vity or density per barrel, and at whatever number it floats, that will
indicate the number of pounds per barrel heavier than water.
Example 1. — Suppose the saccharometer to float at the figure 8, that would indicate
8 lbs. per barrel ; then submit the liquid to the boilin;? test, with the salt as before
directed, and suppose it should show (the barometrical differences being accounted for)
90 *'»', that would be equivalent to 10 per cent of proof alcohol. Refer to the slide rule.
EBULLrnON ALCOHOLMETER. 77
and plape A on the slide against 10 on the upper line of figures, and facing b on the
lower line will be 18, thus showing that 18 Ihs. per barrel haTe been decomposed to
constitute that percentage of spirit; then, by adding the 18 lbs. to the present 8 lbs.
per barrel, the result will be 26 lbs., the original weight of the irort after leaying the
copper.
Example 2. — The saccharometer marks 10 lbs. per barrel, and at the boiling point it
indicates 8S*'** equivalent to 12 gallons of proof spirit per cent. ; place a agulnst 12,
and opposite B will be 21 ^ lbs. per barrel, when, by adding that to the 10 lbs. present,
^1^ lbs. will be the result.
To <ucertain the relative value, — Suppose the price of the 26 lbs. of beer to be S6«. per
Varrel, and the 31^ lbs. beer to be 40«. per barrel, to ascertain which beer will be the
cheapest place 26 on the opposite side of the rule against 36, and opposite 3 Ij^ Ilk )• will
be 43*. 7dL, showing that the latter beer is the cheapest by 3«. 7</. per barreL
By taking an account of the malt liquors by this instrument prior to stocking, it
may be ascertained at any time whether any alteration lias taken place in their condition,
either by an increase of spirit by after fermentation and consequent loiw of saccharum,
or whether, by an apparent loss of both, acetous fermentation has not been going on
towards the ultimate loss of the whole.
This instroment will likewise truly indicate the quantity of spirit per cent created
in distillers* vorts, whether in process of fermentation or ready for the still ; the only
difference will be in the allowances on the slide- rule.
N.B. — The saccharometers applicable to the foregoing rules for beer, ales, &c.,
haTe been adjusted at the temperature of 60^ Fahrenheit, and will be found correct for
general purposes; but where extreme minuteness is required, the Tariation of tempe*
rature must be taken into account ; therefore for every 10 degrees of temperature above
60, -jiyths of a pound must be added to the gross amount found by the slide-rule ; on the
contrary, for every 10 degrees below 60, ^ths of a pound must be deducted.
For cordiaiised Spirits. — The operation in this instance is somewhat different from
that of beers, which have the alcohol created in the original worts $ whereas, in cor-
dial ised spirits, gins, &c., the alcohol is the original, and the saccharine matter, or
'sugar, is an addendum.
If 100 gallons of spirits are required at a given strength, say 50 per cent under proof,
50 gallons of proof spirit, with tbe addition of fifty gallons of water, would effect that
object, and upon testing it by the alcoholmeter, it would be found as correct as by the
hydrometer. But in cordialising spirits it is different, for to the 50 gallons of proof
spirit 50 gallons of sugar and water would be added, thereby rendering the hydrometer
useless, except for taking the specific gravity of the bulk, and according to the quantity
-of sugar present, so a relative quantity of water must have been displaced ; and as the
sugar has no reducing properties, the alcoholmeter will only show the strength of the
cordial in relation to the water contained in it, as the principle indicates, irrespectively
of saccharine or extractive matter present
Suppose, in making 100 gallons of cordial at 50"^*, 3 lbs. of sugar are put to the
gallon, or 300 lbs. to the 100 gallons, that 300lbs., displacing 18^th gallons of water,
only 31fg(th gallons of water instead of 50 have been applied ; the sugar, without
reducing properties, making up the bulk of 100 gallons, which is meant to represent
60 per cent '•^.
The alcoholmeter will only show at the full point of ebullition the alcoholic strength
in relation to the water in the 100 gallons of the mixture, or 35 per ccnt"'i", leaving 15
per cent to be accounted for on the bulk.
As the quantity of sugar present must be determined before that percentage
can be arrived at, a double object will be effected by so doing, namely eliciting in all
instances the quantity of sugar present, as well as the percentage of spirit to be ac-
counted for.
Example 1. — In taking the sp. gr. of a cordial, suppose it to be found 1076, then
submit the liquid to the boiling point, and having ascertained the percentage of alcohol,
and it proves to be 35"*i>% the sp. gr. of alcohol at that strenffth will be found to be 956 ;
deduct 956 from the sp. gr. of the bulk, or 1076, and 120 will remain ; refer that to its
amount en the head line of the table No 2, namely, 120, under which will be found 3,
representing 3 lbs. of sugar to the gallon ; and by running the eye down its column to
opposite the alcoholic strength indicated (35"i>') will be found l4-9,which represents the
percentage of water displaced by the sugar, and which amount of 14-9, added to the
35 per cent ascertained, makes the total upon the balk 49*9 per cent ■*!**, with 3 lbs. of
sugar to the gallon.
Far Gins, ^-c. — Example 2. In taking the sp. gr., suppose it to be found 957 ; then
submit to the boiling point, and it proves to be 14"P', whose sp. gr. is 937, which
deducted from 957, leaves sp. gr. 20 ; on the head-line of table No. 2, under 20, will
be found 8.oz., or ^ lb. of sugar to the gallon, and on running the eye down to opposite
78 ELAINE,
U* 1", will be found 3*0, which added to the 14, makes the total on the hulk 17 per
cent." p% with 50 Ihs. of sugar to the 100 gallons.
To chemists for their tinctures, &c., this instrument will be found essentially uiefuL
N.B.->Care must be taken that the mercury is entirely in the bulb of the thenuo-
meter before it is fixed on the stem for operation, and in all cases (except for water)
the salt must be used.
EDGE TOOLS ; more properly cutting tooU^ of which the chisel may be regarded
as the type. Holtzapffel, whose book on Mechanical Maniptilation is the best to be
found in any language, divides cutting tools into three groups, — namely paring tooli,
scraping tools, and shearing tools.
Firtt Paring or splitting tools, with thin edges, the angles of which do not exceed
sixty degrees ; one plane of the edge being nearly coincident with the plane of the
work produced (or with the tangent in circular work). These tools remove the
fibres principally in the direction of their length, or longitudinally, and they produce
large coarse chips, or shavings, by acting like the common wedge applied to mecha-
nical power.
Secondly, Scraping tools, with thick edges, that measure from sixty to one handred
and twenty degrees. The planes of the edges form nearly equal angles with the
surfiiee produced, or else the one plane is nearly or quite perpendieolar to the fhee
of the work (or becomes as a radius to the circle). These tools remove the fibres
in all directions with nearly equal fitciiity, and they produce fine do8t*like shaTiogi
by actina; superficially.
Thir<&f, Shearing, or separating tools, with edges of from sixty to ninety degree
generally duplex, and then applied on opposite sides of the substances. One plaae of
each tool, or of the single tool, coincident with the plane produced.
Mr. James Bouydell introduced a process which professes to produce cheap edge
tools of excellent quality. We believe the result has not been so satisfactory as the
patentee expected. He welds iron and steel together in such a manner thst when
cut up to form edge tools, the steel will constitute a thiu layer to form the catting
edge. He piles a slab or plate of steel upon two or more similar plates of iroo, heats
in a furnace to a good welding heat, and then passes between grooved or other
suitable rollers, to convert it into bars ; the steel being in a thin layer either on one
of the outer surfaces of the bar, or between two surfaces of iron according to the kind
of tool to be made therefrom. The bars thus produced are cut up and manafactared
into the shape of the desired articles by forging. If the cutting edge is to extend
but a short distance, the steel is applied only near one edge of the pile. The componnd
bars which have the steel on one side are suitable for chisels and other tools, which
have a cutting edge on one side, the iron being ground away when making or sharpen-
ing the tool. See Cutlery; Steel.
EDULCORATE (Edulcarer, Fr.; AustuMen, Germ.) is a word introdoeed by the
alchemists to signify the sweetening, or rather rendering insipid, of acrimonious poi-
verulent substances, by copious ablutions with water. It means, in modem language,
the washing away of all particles soluble in water, by agitation or trituration with this
fluid, and subsequent decantation or filtration.
EFFERVESCENCE. (Eng. and Fr. ; Aufhrnusen, Germ.) When gaseous matter
is suddenly extricated witii a hissing sound during a chemical mixture, or by the
application of a chemical solvent to a solid, the phenomenon, firom its resemblance to
that of simmering or boiling water, is called effervescence. The most familiar ex-
ample is afforded in the solution of sodaic powders ; in which the carbonic acid gas of
bicarbonate of soda is extricated by the action of citrio or tartaric acid.
EFFLORESCENCE (Eng. and Fr.; Verwittern, Germ.) is the sponlaineons con-
version of a solid, usually crystalline, into a powder, in consequence either of the
abstraction of the combined water by the air, as happens to the crystals of sulphate
and carbonate of soda ; or by the absorption of oxygen and the formation of a salme
compound, as in the case of alum schist, and iron pyrites. Saltpetre appears as an
efflorescence upon the ground and walls in many situations.
EGGS, HATCHING. See Incubation, AnTincxAL.
EIDER-DOWN U so called because it U obtained from the £u/er-duck. These
birds build their nests among precipitous rocks, and the female lines them with fine
feathers plucked from her breast, among which she lays her five eggs. The nauves
of the districts frequented by the eider-ducks let themselves down by cords among
the dangerous cliffs, to collect the down from the nests. It is used to fill coverlets,
pillows, cushions, &c.
ELAINE (called also Olsine) is the name given by Chevreul to the thin oil, which
may be expelled from tallow and other fats, solid or fluid, by pressure either in their
natural state or after being saponified, so as to harden the stearine. It may be extraeted
also by digesting the fat in seven or eight times its weight of boiling alcohol, specgrav-
ELECTRIC CLOCKS.
79
0-79S, till it dittolyes the whole. Upon cooling the solution, the itearine falU to the
bottom, while the elaine collects in a layer like olive oil, upoa the surface of the super-
natant solution, reduced by evaporation to one eighth of its bulk. If this elaine be now
exposed to a cold temperature, it will deposit its remaining stearine, and become pure.
Bracoanot obtained it by exposing olive oil to a temperature of about 21^ F. in order
to cause the congelation of the margarine or stearine (?). The elaine was a greenish
yellow liquid ; at 14^ F. it deposited a little margarine. See Oils and Stsakine.
ELASTIC BANDS. ( Twtu AuOquet^ Fr. ; Federharz-zeige, Germ.) See Caout-
chouc and Braimiio Machine.
ELASTICITY. The property which bodies possess of occupying, and tending
to occupy, portions of space of determinate volume, or determinate volume and figure,
at given pressures and temperatures, and which, in a homogeneous body, manifests
itself equally in every part of appreciable magnitude (NichM). The examination of
this important subject in Kinetics does not belong to this work. A few remarks,
and some explanations, only are necessary.
Ehstie Pre$9wre is the force exerted between two bodies at their surface of contact.
Compresaicn is measured by the diminution of volume which the compressible
(elastic) body undergoes.
7%e Modulut or Coefficient of Elasticity of a liquid is the ratio of a pressure applied
to^ and exerted by, the liquid to the accompanying compression, and is therefore the
reciprocal of the compressibility. The quantity to which the term Modulus of
Elaatieitjf was first applied by Dr. Young, is the reciprocal of the extensibility or
longitudmal pliability. (See the Edinburgh Transactions, and those of the Royal
Society, for the papers of Barlow, Maxtcellj and iZanAine, and the British Association
Reports for those of Fairhaim^ HodgkinsouL, &c.)
Yarions tables, showing the elssticity of metals, glass, &c., have been constructed,
and will be found in treatises on mechanics. The following notices of the mecha-
nical properties of woods may prove of considerable interest The experiments were
by Chevaadier and Wertheim.
Rods of square section 10 mm in thickness and 2 m in length were prepared, being
cut in the direction of the fibres, and the velocity of sound in them was determined by
the longitudinal vibrations, thmr dasticity from their increase in length, and their co-
hesion by loading them to the point of rupture. Small rods were cut in planes per-
pendicular to the fibre grain (in directions radial and tangential to the rin^s of growth)
and their elasticity and sound volocity were measured by the lateral vibrations. It was
thus again established, that the coefficients of elasticity, as deduced from the vibrations,
come out higher than those derived from the elongation.
Name* of the woods.
AcSkda
Fir -
Hornbeam
Birch
Bereb
Oak .
Holm- Oak
Pine -
Sycamore -
A&h .
Alder
A«prn
Maple
Poplar
Elm .
Den-
sity.
Soond Telocity.
Coefficients of elns-
tlcity.
Cohesion.
L.
B.
T.
L.
R.
T.
1.
R
T.
0-717
14-9
_«
__
1216-9
^
__
7-98
—
..
0-4<)3
13*96
8-05
4-72
1113-2
945
34-1
4-18
0-220
0 297
0-756
11-80
10-28
7-20
108.V?
20H-4
103-4
299
l-«)7
0-618
0*812
13-3-2
6-46
9-14
9l'7-2
81-1
155-2
4-30
0-823
1063
0-823
1006
11-06
8-53
980-4
2G9-7
ise-3
8-57
0-885
1-752
080<t
.«
^—
_
9n8
^
-^
6-49
_.
— -
0-878
11-58
9-24
7-76
921-3
188-7
129-8
566
0-582
0-406
0-JW9
10-00
8-63
4-78
A64-1
97-7
28-6
2-48
0-*/56
0-196
0-682
13-43
9-()8
6-85
1163-8
134-9
80-5
6-16
0-S22
0-610
0697
14-05
8-39
7-60
1121-4
111-3
102-0
6-78
0-218
0-408
0-601
13-95
8-25
6-28
1108-1
98*3
59'4
454
0-329
0-175
0-602
16 80
9-72
6-48
1076-9
107-6
43*4
7-90
0-171
0-414
0-674
12 36
9-26
6-23
1091-4
157-1
727
3-ft8
0-716
0-371
0-477
12-89
8-44
6-32
517-2
78'3
38-9
1-97
0-146
0-214
866
611
^^
122-6
634
—
0-345
0-366
L refers to rods cut lengthwise with the grain,
R to those cut In a direction radial, and
T to tbo^e tangential to the annual rings.
EL ATEBIUM. A peculiar extract obtained from the juice of the wild cucumber.
(^Momordica daterivrn),
ELDER. (Samlmeus nigra, Sureau, Fr. ; Hohlunder, Germ.) Pith balls for elec-
trical purposes are manufactured fh)m the pith of the elder tree, dried. The wood is
employed for inferior turnery work, for weaver*s shuttles, netting pins, and shoe-
makers* pegs. Its elasticity and strength render it peculiarly fitted for these
latter purposes.
ELECTIVE AFFINITY. iWahherwandtschafty Germ.) See Decomposition,
BQuivALxirrs.
ELECTRIC CLOCKS. The application of electricity as a motive power to
docks, and as a means of transmitting synchronous signals or time, is naturally inti-
80
ELECTRIC CLOCKS.
matelj connected with the attempts (not yet realised in an economic point) to apply it
as a motive power to machinery, and with its application, so fully realised (see article
Electro-telegrapht), to telegraphy proper ; and it has grown up side by side with the
latter. Prof. Wheatstone's atteniion wasdirected to it in the very early days of telegraphy.
Without entering upon the history of electric docks, it will suffice to describe tvo
principles on which they have been constructed, and which are best known,— Bains
and Shepherd 8. In the former, electricity maintains the pendulum in motion, and the
pendulum drives the clock-train ; in the latter, the motion of the pendulum is maintained
by electricity, but the clock-train is driven by distinct currents, sent to it by means of
pendulum contacts.
The bob of Bain's pendulum consists of a coil of wire, wound on a bobbin with a
hollow centre.- The axis of the bobbin is horizontal. Bar magnets, prescnf:n/r
similar pules, are fixed on each side of the coil, in such a position that, as the pendnlom
oscillates right and left, the poles on either side may enter the coil of wire. It is one
of the laws of electric currents, when circulating in a helix, or spiral, or coil, or even
in a single ring, that each face of the coil presents the characters of a magnetic pole,
of a south pole if the current circulates in the direction in which the hands of a
watch move, of a north pole, if it circulates in the reverse direction. Things are so
arranged in Bain's pendulum that a battery current is alternately circulating in and
cut off from the coiL When the current is circulating, the coil has the character of a
686 magnet, with a north end and a south end; if
the permanent magnets present north poles, the
north end of the coil- bob will be repelled from
one of the magnets, while its south end will be
attracted by the other magnet This consti-
tutes the impulse or maintaining power in one
direction. Now the connections are sach that,
when the arc of vibration is complete and the
pendulum ready for the return vibration, the
pendulum rod pushes aside a golden slide, by
which the electric circuit had been completed,
and the current is cut off; the pendulamisthns
able to make its return vibration by mere
gravity. It starts to repeat the above operations
by mere gravity; but, ere it completes the arc,
the rod pushes back the slide, and again com-
pletes the electric circuit, and gives rise to a
second impulse, and so on. A small annount of
magnetic attraction is sufficient to supply the
necessary amount of maintaining power. One
pair of zinc-copper, buried in the moist earth,
has been found ample.
In an ordinary clock, the train is carried hy
a weight or by a spring, and the time is regn-
lated by the pendulum. In Bain's the time is
regulated and the train is driven by the pendu-
lum. The rod hangs within a crutch in the
usual way ; the crutch carries pallets of a par-
ticular kind, acting in a scape- wheel ; and from
the latter, the motion is transmitted to a iraia
of the usual character; but much lighter. For
large clocks, Mr. Bain proposes a modification
of the slide, which shall invert the current at
each oscillation, so as to have attraction as a
maintaining power in both oscillations. The
general arrangement of the pendulum is shovn
in Jig. 686. B is the pendulum bob, ▼ith >»
coil of wire, the ends of which pass up on either
side of the rod. z and c are the battery pla^
w ith their attached wires d and d'. The arrows
o show the course of the voltaic current firom the
plate c by the wire d^, thence down the pendaj
lum rod by the right hand wire, through the coil
B, up by the wire on left side of rod, then hy
^ -• ' ' the wire c, along the slide at e, and by the
wire D to the zinc plate z. When the slide e is in position, the circuit is complete,
and the bob is attracted by the n pole of one of the magnets, and repelled by the a
ELECTRIC CLOCK& 81
pale of the other. When IlieaUdeU ditpUecd, the UtnctloneeMM, tad tlupatdnlnm
n left to the mere action otgn-ritj.
Sfaepberd'a electric clock has m, Temontcdr eMapemmt. Then U no direct ocnin«>~
tion betveen the dectric tbree and the pendulDin, or helween the pendnliun and the
clock Inio. The attTiu:tiTe power, deriTCd trtmt the electric eorrent, ii llnplf em-
plojcd lo nice the nme nnall weight to the nine bmght i tai the clock-tnun it
carried by the attrKetire force derived from electric cnrrcnta, whose eireoiu are com-
pleted bj the peDdnlmn tonchiag contact ipringa. The pendolnm ii thua protected
from the infloeoee of change in the fbree of the cnrrent, or IVom Irrenlar reaiataocet
ia the train. Fig-tSI U a penpectiTe view of ibia peodalun, wiu batteries ■ m,
M7
attached, and the dock coanectioDi and thou of iu batteries, $t*t, thown. The
electricinr teavet the pendnlam bMterj by the wire a, and retnraa to it b; the wire w.
Vol. iL O
82 ELECTRIC CLOCKS.
There is only one break in this circnit, namely, at s, which is a slender spring &oed
with platinum, that is in contact with platinum on the pendulum at the extreme of its
right Tibration, but at no other time. The wire ▲ reaches the pendulum from the
battery by the coils b, the plate o, and the frame d ; the wire F goes direct from the
spring E to the zinc z. From this arrangement, it happens that eyery time the con-
tact at E is completed, the iron core, of which the ends m s are visible, ooDtained
within the coils b, becomes a magnet, and when the contact at b 14 broken, the
magnetism ceases. The poles n b have, therefore, a power alternately to attract aad
to release a, which is a plate or armature of soft iron, moving on an axis, as shown
in the figure, and to which is attached a bar b, with a counterpoise t. We have nid
that the office here of the electric force, is merely to raise a weight; the fall of the
weight maintains the pendulum in motion. When the armature a is attracted, the
lever b is raised; this raises the wire c into a horizontal position, and its other part
d into a vertical position; the latter is caught and retained by the latch or detent e; so
that when the magnetic attraction ceases, the counterpoise t descends with the lever
b ; and so the armature a leaves the electro-magnet n s. But the wire d remaiB$
vertical, and its other part with the small weight e remains horizontaL Now, when
the pendulum makes its left hand oscillation, the point of the screw /impinges upon
the stem g, and carries it a little to the left ; this raises the detent e, and liberates the
piece d c, which descends into its original position by gravity ; the small ball c adds
to its weight. In descending, the vertical piece c strikes against the point of the
screw ht and gives a small impulse to the pendulum p. The ball c is not larger than
a pea, and its fall is not an eighth of an inch; but the impact is sufficient to keep the
pendulttm in motion; and it is constant, being this same body falling through the
same space; and is independent of any variation in the battery power, which latter is
only concerticd in raising the ball. The arc of the pendulum's vibration is regulated
by adjusting the small b^l to a greater or less distance from the centre. Provision is
thus made fbr maintaining the pendulum in motion, and giving it an impact of con-
stant value. If this arrangement is in connection with a compensating mercurial pen-
dulum, extreme accuracy of time-keeping is attained. The next step is to transfer
the seconds, thus secured, to a dial or clock. The same movement of the keeper a
with its counterpoise i, has sometimes been made to impart motion to the seconds
wheel of a clock train; but more commonly the clock train is distinct, as shown in the
drawing, and is carried by a special electro-magnetic arrangement, in connection with
separate batteries, z c, zc^ the contacts of which are, however, under the control of
the pendulum. Insulated springs, k and ^ are fixed near the top of the rod ; from k
a wire leads to the silver s, of the left hand battery ; and from / another wire leads to
the zinc z, of the right hand battery. The other metals of the respective batteries are
connected by a wire with an electro-magnet within the clock, the other end of the said
electro-magnet being connected with the metal bed and frame of the pendulum. When,
therefore, the pendidum oscillates to the right, the circuit is completed at k ; and the
current of the left hand battery circulates from 9 through the wire k ; and thence
through the metal frame and by the wire to the clock, and so to the zinc z. When
the oscillation is to the left and 1 is in contact, the right band battery is in action ; and
the current circulates from « through the clock, to the metal fhune, and thence to /
and to the zinc z of the battery. In one case, a voltaic current enters the clock by
the wire shown below, and leaves it by the upper wire ; and, in the other case, it
enters by the upper and leaves by the lower wire. There is a double set of electro-
magnets within the clock, showing four poles in all ; there are also two magnetised
steel bars, mounted see-saw fashion, with their poles alternate, and facing the four
electro-magnetic poles. When the current enters the clock from below or in one
direction, the bars oscillate this way; when it enters from above or in the reverse
direction, they oscillate that way. They are both fixed at right angles to aad upon
the same axis ; which axis carries a pair of driving pallets, that act on a scape- wheel,
and so the clock-train is driven. It will be seen at a glance, that two or more clocks
may be connected in the same circuit, as readily as one ; it being merely necessary in
such case to modify tHe battery power, to correspond with the work to be done.
For instance, three such clocks have been going for several years at Tonbridge by
the same pendulum ; several are actuated in like manner at the Royal Observatory,
Greenwich. Nor is it necessary that the clocks should be in the same room with the
pendulum, or in the same building, oir even in the same parish. All the clocks above
referred to, are variously distributed ; and one of the Observatory clocks is six miles
distant from its penduliui, being at the London Bridge Station of the South-Eastem
Railway.
In cases where it has not been found convenient to drive the dock train, especially
in the case of a public one, the movement of which is heavy, great advantage has
been derived for regulating the oscillations of the pendulum of the large clock, by
means of electric currents, under the control of a standard pendulum. Mr. Jones
ELECTRIC CLOCKS. 88
hjM adopted thif method* and it is likely to meet with much fiiTour. The turret
clock, under this arrangement, is driven hy weights in the usoal way, and the time is
regulated hy a pendulum. The hoh of the pendulum is placed under a condition
anulogoaB to that of Bain's (Jig, 686), the permanent magnet, however, heing attached
to tlie pendulum, and the electro-magnet fixed facing it If currents are made to
circulate syncfarononsly in the latter, by means of a standard pendalum, the oscillations
of the pendulum of the turret-clock are constratoed to accord with those of the
standard, and a very perfect s^rstem of time-keeping is obtained. This is practised at
LiTerpool ; and has just been introduced at Greenwich.
Under the abore arrangements the dock is controlled by the standard pendulum
second by second, and the two keep time together throughout the day. There are
cases in which it is sufficient, and also more convenient, to correct a clock once a dar
only by means of a telegraph signal transmitted from a standard clock. This is
managed in several ways. There is a dock at the Telegraph Office in the Strand ;
a good r^ulator, adjusted to gain a second or two during the twenty-four hours, and
to stop at 1 P.M. A telegraph signal is sent from the Royal Observatory precisely at
one, that drops a time-ball at the Strand office, which, in &iling, staru the clock.
At Ashford, seventy-three miles from Greenwich, there is an electric clock which has
a gaining rate, and which is so constructed that the liattery circuit is opened at one
o'clock by means of pins and springs attached to the movement, and the clock there-
fore stops. At 1 P.M., Greenwich mean time, a signal is sent through the Ashford
clock from the Royal Observatory, which starts it at once at true time. At the Post
office, Lombard Street, there is a clock which, in the course of the twenty-four hours,
raises a weight At noon a telegraph signaJ is sent from Greenwich, which passes
thro«|^ an electro-magnet t the latter attracu an armature of soft iron and liberates
the ball, which Ihlls, and in £Uliag it encounters a crutch, or lever, attached to the
second's hand, and thrusts it this way or that, as the case may be ; but so as to bring
k io sixty seconds on the dial, and thus to set the dock right
Intermediate between the one method of sending a signal every second to regulate
a dock, and the other method of sending it once a &y, we have the followlog arrange
ment of Bain's for sending it once an hour. Fig, 6tf8 shows the arrangement, with
part of the dial removed* to show the position of the electro-magnet The armature
IS below ; it carries a vertical stem, terminating ^
above in a fork. Its ordinary position is shown
by the dotted lines. The minute hand (partly
removed from the cut) carries a pin on its back
surface. When the hand is near to sixty mi-
nutes, and an electric current is sent through
the magnet the armature is attracted upwa^
and the fork takes the position shown by the
fnli^ lines at the top of the dhU, and, in doing
so, it enoonnters the pin and forces the hand
into the vertical position, and sets the clock
to true time, providing the signal comes from
a standard dock, or is sent by hand at true
time. A dial of moderate character keeps so
near to time, that once or twice a day would
be, for all common purposes, often enough to
correct it *
Fig. 689 is an arrangement of Bain's, by
which a principal dock, showing seconds,
sends deetric currents at minute intervds to other docks, and causes the hand to
move minute by minute, a is a voltaic battery ; b is the prindpaldock, which may
be an electric dock or not at pleasure} o and h are two out of many subordinate
docks. The seconds hand of the principd clock completes a voltaic circuit twice
(for the case of two docks) during the minute; at the 80 seconds for the dock o,
and at the 60 seconds for the dock h. The clock h shows time in leaps from one
minute to the next; and the dock o from one half minute to the next half minute.
As many more contacts per minute may be provided for the seconds hand of the
prime dock as there are subordinate clocka
Next akin to the time signals above described, and which act automatically upon
docks, either to drive the dock-train or to correct the dock errors, are mere time
signals, which are extensivdy distributed throughout the country by the ordinary tele-
graph wires, and are looked for at the various telegraph stations, in order to oompare
the office dials with Greenwich mean time, and to make the necessary correction;
tbcy are also re-distributed b^ hand the moment they appear, through sub-distriots
branching from jnaetion stations. Large black balls, hoisted in oonipionous stations,
oa
84
ELECTRICITY.
are also dropped dailj by electric currents in yarioos places, for the general infor-
mation of the pablic, or of the captains of ships. — G. V. W.
689
ELECTRICITY /or Blattmg in Mines and Quarries, Professor Hare was the fint
who entertained this idea, bat Mr. Martin Roberts devised the following process, u
order not to be called upon to make aAresh a new apparatus for each explosion, Mr.
Roberts inyeuted cartridges, which may be constract^ beforehand. With this new,
two copper wires are procured^ about a ten^ of an inch in diameter, and three yaiw
in length, well covered with silk or cotton tarred, so that their insulation mBj be
very good. They are twisted together (fg. 690) for a lf?8"lj
six inches, care being taken to leave their lower extremities nee.
for a length of about half an inch (separating them about ban ia
inch), from which the insulating envelope is removed, inorder tostietca
between them a fine iron wire, after having taken the precanuon
of cleaning them welL The upper extremities of the two eopptf
wires are likewise separated, in order to allow of their being plMM
respectively in communication with the conductors, that abut npoQ
the poles of a pile. The body of the cartridses is a tin tube, three
inches long, and three quarters of an inch in diameter, the solaeringi
of which are very well made, in order that it may be perfectly imper*
meable to water. A glass tube might equally well be em^oyed,
were it not for its fragility, which lus caused a tin tube to be pj^
ferred. The system of copper wires is introduced into ^^^
fixing them by means of a stem that traverses it at such a beig
that the fine iron wire is situated, in the middle of the tin wie,
so arranged that the ends of the copper wire do not ^/^^[!
touch the sides of the tube (Jig, 691). The cork is firmly ww»
the upper extremity of the tube witn a good cement Mr. "frfr
recommends for this operation, a cement composed of one part ^°^
wax and two parts of resin ; the tube is then filled with P^^^^^ ^
its other extremity, which is likewise stopped with a cork, ^"^
cemented in the same manner. Figwre 692 indicates the ""**'
in which the cartridge is placed in the hole, after having ca
fully expelled all dust and moisture \ care must be taken ^^^
cartridge is situated in the middle of the charge of powder tbai
introduced into the hole. Above the powder is placed s P'*^^
straw or tow, so as to allow between it and the powder a smtU apjf
filled with air ; and above the plug is poured dry sand, untU the ikn«
is filled with it The two ends of the copper wires that «>»* ** y^
the cartridge are made to communicate with the poles of the p •
by means of conductors of sufficient length, that one id<^3[ ^ ^
tected ftum all dangers arising fh)m the explosion of the ^"^^ ^
M. Ruhmkorff, and after him, M. Verdu, have successfully tried to 'v^^ij^llof
induction spariL /or the incandescence of a wire, in order to bring about the ^^^^
the powder. This process, besides the considerable economy that it presents-'^
instead of fW>m fifteen to twentv Bunsen's pairs, necessary for causing tbe Mff^"^
ELECTRlCnr. 85
of the win, il reqairei but ■ riagle ooa for producing the iDdaetioa ipcrk, — poMcuei
th« adruitages of being le« loiceptibLe of dermngemeiit. Ontj it tu neccsur; to
clrcDJt preienn too grett ■ reaiituiee, the induction apark ia able to pM* throagh
the powder without influnmg it. M. Ruhmkorff fani eoneeiTed the bippv idea of
teekmg for ■ medium, wbicb, more euily inflsnunable b; the spark, may bring About
the ignition of the powder in all pouible couditioni. He found it in Statham'i fiue«*,
which are prepared bj taking two end* of copper wire covered with ordidarj gotta
pereha ; thej are twiited (^.693), ud the euds are bent m> aa to make them eater
mto an en'riope of vnleaoiied (lolphured) gntta percha, which hai been cut and
drawn off from a copper wire that had been for a bog time covered with it. Upon
Ihia envelope a sloping cut a, i, is formed; aod after hariug maintained the ex-
tremitiei of the cop^r wire* at aboat the eighth of an inch fh>m each other, their
points are covered with fnlminaU: of mercur;, in order to render (he ignition of the
powder more earf. The cut is filled with powder, and Ibe whole is wrapped round with
a piece of caoulcbonc tube, e, d, or else it is placed in a cartridge filled with powder.
In the Btatham fiuee*, it is the aDlphide (sulphuret) of copper adhering to the wire,
produced by the action of the Tnlcaaised gutta percha which is removed from the
copper wire that it covered, which by being iufiamed under the action of the induction
spark bringi about an explosion, Bnt it is neceisary to take care wbeu tbe fusee has
been prepared, as we have pointed oat, to try it in order to regulate the extent of the
lolntian of coolianitj. It might, in fact, happen that while sliU belonging to tbe same
envelope of a copper wire, th« idiealh oF a vulcanised gutta percha wi& which the
foaee is furnish^, maybe more or le« impregnated with sulphide of ropperi
DOW, it the solphlde of copper is in too great quantity, it becomes too good a
eoodnctor, and prevents the spark being produced; if, on the conltary, it is not in a
■officiently Urge quantity, it does not tn^cleutly facilitate the discharge.
The Erst trials on a large scale of the application of tbe proct^i that we Just
deaeribed, were made with RohmkorS's ioduction apparatus, by the Spanish colonel,
Verdo, in tbe workshops of M. Uerkmas, manufacturer of gatla percha covered wire,
at La Villette, near Paria. Experinieiita were made luccesaively upon lengths of
wire of «00, GOO, 1000, SOOO, and up to S6,000 metres (ofS'Za feetji and the success
was always complete, whether with a circuit composed of two wires, or replacing one
of the wire* by the earth i two ordinary Bunsen's pairs were sufficient for producing
the induction spark with Rubmkorff's apparatus. Since his first researches with
H. Ruhmkorff, M. Verdu has applied himself 1o fresh researches in Spain ; and he
«ai satisfied, by many trials, that of all explosive substances, not any one was nearly
so sensitive as fulminate of mercury; only, in order to avoid (he danger that arises
from the fiwylily of explosion of this componnd, he takes the precaution of intro-
dncing the extremity of the fhsecs into a small gutta percha tube, closed at the end.
After having filled with powder this species of little box, and having closed it
86 ELECTRIC LIGHT.
hermetieaUy, the fhsees may be carried about, may be handled, may be allowed to
fall, and even squeezed rather hard, withoat danger. The elastic and, leather-like
nature of gutta percha, which has been carefully softened a little at the fire, preserves
the fulminate f^om all chance of accident We may add, that with a simple Bunsen's
pair, and by means of Rahmkorff *s induction apparatus, M. Verdu has succeeded in
producing the simultaneous explosion of six small mines, interposed in the same
circuit at 320 yarda from the apparatus. He has not been beyond this limit ; but he
has sought for the means of acting indirectly upon a great number of mines, by
distributing them into groups of five, and by interposing each of these groups in a
special circuit The fusees of each group are made to communicate by a single wire,
one of the extremities of which is buried in the ground, and whose other extremity
is near to the apparatus. On touching the induction apparatus successively with each
of the free ends that are held in the hand, which requires scarcely a second of time,
if there are four wires, that is to say, four groups and consequently twenty mine%
twenty explosions are obtained simultaneously at considerable distances. There are
no limits either to the distance at which the explosion may take place, or to the
number of mines that may thus be made to explode.
ELECTRIC LIGHT. Various attempts have been m»le, fVom time to time, to
employ electricity as an illuminating power ; but hitherto without the desired success.
The voltaic battery has been employed as the source of electricity, and in nearly all
the arrangements, the beautiful arc of light produced between the poles, from the
points of the hardest charcoal, has been the illuminating source. One of the great
difficulties in applying this agent arises from the circumstance that there is a trans-
ference of the charcoal from one pole to the other, and consequently an alteration in
the distance between them. This gives rise to considerable variations in the intensity
and colour of the light, and great want of steadiness. Various arrangements, many
of them exceedingly ingenious, have been devised to overcome these difficulties.
The most simple of the apparatus which has been devised U that of Mr. Staite,
which has been modified by M. Archereau. Two metal columns or stems, to which
any desired form can be given, are connected together by three cross pieces, so as to
form one solid frame *, one of these cross pieces is metallic, it is the one which occupies
the upper part of the apparatus ; the others must be of wood. These latter serve as
supports and points of attachment to a long bobbin placed parallel to the two columns
and between them, and which must be made of tolerably thick wire, in order that the
current, in traversing it without melting it, may act upon a soft iron rod placed in the
interior of the bobbin. This iron rod is soldered to a brass stem of the same calibre,
and of the same length, carrying at its free extremity a small pulley. On the opposite
side the iron carries a small brass tube, with binding screws, into which is introduced
one of the carbons, when the entire rod has been placed in the interior of the bobbin.
Then a cord fixed to the lower cross piece, and rolling over a pulley of large diameter,
is able to serve as a support to the movable iron rod, running in the groove of the
little pulley. For this purpose, it only requires that a counterpoise placed at the end
of the cord shall be enabled to be in equilibrio with it. The metal cross piece which
occupies the upper part of the apparatus, carries a small brass tube, which descends
perpendicularly in front of the carbon that is carried by the electro-magnetic stem,
and into which is also introduced a carbon crayon. By means of a very simple ad-
justment, this tube may besides be easily regulated, both for its height and for its
direction } and consequently the two carbons may be placed very exactly above one
another. The apparatus being adjusted, we place one of the two metal columns of
the apparatus in connection with one of the poles of the pile, and cause the other
pole to abut upon the copper wire of the bobbin (one end of which is soldered upon
Its socket). The current then passes from the bobbin to the lower carbon by the rod
itself that supports it, and passing over the interval separating the two carbons, it
arrives at the other pole of the pile by the upper cross piece of the apparatus and the
metal column, to which one of the conducting wires is attached.
So long as the current is passing and producing light, the bobbin reacts upon the
iron of the electro*magnet rod, which carries the lower carbon and attracts it on
account of the magnetic reaction that solenoids exercise over a movable iron in their
interior. It is this which gives to the carbons a separation sufficient for the luminous effect
But immediately the current ceases to pass, or is weakened, in consequence of the
consumption of the carbons, this attraction ceases, and the movable carbon, acted on
by the counterpoise, is found to be drawn on and raised until the current passes
again ; equilibrium is again established between the two forces, and the carbons may
be employed again. Thus, in proportion as the light tends to decrease, the coun-
terpoise reacts; and this it is that always maintains the intensity of the light equal.
M. Breton has an apparatus which differs somewhat from the abovs, and M.
Foacault has also devised a very ingenious modification.
KLECTEIC LIGHT.
87
H. Daboacq bH made b7 fkr the moat neecMfiil mmagtmeat, tat m dctcription of
wluch we are indebted to Z?e Is A'ra'i TVulin oil £J(eMi%, (TuuLated ti]' C. V. Wftlker.
The two cmrbooi, between which the light i* dereloped, bora in conuuit with the
>ir. and ihorten «t each iutant; a mechaDiim ii conaeqnently neecMaiy, which
bringi them near to each other, propoTtionalt j to the progreii of the Miabaftion g
694
ud lince the ponliTe carbon mffen a more rapid oombnltian than the negative, it
moM travel more rapidlj in hce of thla latter ; and this in a relation which Tariea
with the thiekneu RQd die natnre of the carbon. The meehaniim mn*t MtJify all
theae exigencies. The two carbooi are nnceasingl; «olicited towarda each other,
the lower carbon bj a (pir&l ipring, that caoies it to rite, and the upper carbon bj
itt weight, which Cftmeg il to deecend. The nune axii i« common to them.
The galTUiic current ii prodnced by a Bnnaen'i pile of from 40 ti
88 ELECTRO-METALLURGY.
It arriTes at the two carbons, as in apparatus already known, passing throagh a liollov
deetro-magnet} concealed in the column of the instrument. When the two carbons
are in contact, the circuit is closed, the electro*magnet attracts a soft iron, placed at
the extremity of a lever, which is in gear with an endless screw. An antagonist
spring tends always to unwind the screw as soon as a separation is produced between
the two carbons ; if it is a little considerable, the current no longer passes, the action
of the spring becomes predominant, the screw is unwound and the carbons approach
each other until the current, again commencing to pass between the two carbons, the
motion that drew them towaids each other is relaxed in proportion to the return of
the predominance of the electricity orer the spring ; the combustion of the carbons
again increases their distance, and with it the superior action of the spring ; hence
follows again the predominance of the spring, and so on. These are altematiyes of
action and reaction, in which at one time the spring, at another time the electricity,
has the predominance. On an axis, common to the two carbons, are two pulleys:
one, the diameter of which may be varied at pleasure, communicates by a cord with
the rod that carries the lower carbon, which corresponds with the positive pole of the
pile ; the other, of invariable diameter, is in connection with the upper or negative
carbon. The diameter of the pulley, capable of varying proportionately to the using
of the carbon, with which it is in communication, may be increased from three to
five. The object of this arrangement is to preserve the luminous point at a con-
venient level, whatever may be the thickness or the nature of the carbons. It is only
necessary to know that at each change of kind or volume of the carbon, the diameter
of the pulley must be made to vary. This variation results from that of a movable
drum, communicating with six levers, articulated near the centre of the sphere ; the
movable extremity of the six arms of the lever carries a small pin, which slides in
cylindrical slits. These slits are oblique in respect of the sphere ; they form inclined
planes. A spiral spring always rests upon the extremity of the levers ; so that, if
the inclined planes are turned towards the right, the six levers bend towards the
centre, and duninish the diameter. If, on the contrary, they are turned towards the
left, the diameter increases, and with it the velocity of the translation of the carbon,
which communicates with the pulley. We may notice, in passing, that this apparatus
is marvellously adapted to the production of all the experiments of optics, even the
most delicate ; and that, in this respect, it advantageously supplies the place of solar
light As it is quite impossible to describe accurately the minute arrangements of
this instrument, the letters of reference have not been used in the text
Dr. Richardson informs us, that although Mr. Grove calculated, some years ago,
that for acid, zinc, wear and tear, &c. of batteries, a light equal to 1444 wax candles could
be obtained for about Ss, 6d. per hour, the cost of the light employed for about five
minutes at Her Majesty*s Theatre, as an incident in the ballet, which was obtained by
employing 75 cells of Callan's battery of the lar^st size, was said to be 2/. per night
or at the rate of 20/. per hour. In this calculation we expect we have not a fair re-
presentation of all the conditions. To obtain a light for ten minutes, a battery as
large must be used as if it were required to be maintained in activity for hours — and
probably the battery was charged anew every evening. There can be no doubt but
the cost of light or of any other ybrcc from electricity, with our present means of pro-
ducing it must be greatly in excess of any of our ordinary means of producing illu-
mination. For a consideration of this subject, see Electro- motite Enginxs. Mr.
Grove proposed a light which should be obtained from incandescent platinum, but the
objection to this was, that after a short period, the platinum broke up into small par-
ticles, the electric current entirely disintegrating the metal. Mr. Way has lately
exhibited a very continuous electric light, produced from a constant flow of mercury
rendered incandescent by the passage of the electric current
ELECTRIC WEAVING. M. Bonelli devised a very beautiful arrangement by
which alt the work of the Jacquard loom is executed by an electro- magnetic arrange-
ment The details of the apparatus would occupy much space in the most concise
description, and as the invention has not passed into use, although M. Froment has
modified and improved the machine, we must refer those interested in the subject to
the full description given in De la JRive's Treatise on Electricity by Walker,
ELECTRO-GILDING BATH. See Ctaiodes.
ELECTRO-METALLURGY. The art of working in metals was carried on
exclusively by the aid of fire until the year 1839. At that epoch a new light dawned
upon the subject ; considerable interest was excited in the scientific world, and much
astonishment among the general public by the announcement that electricity, under
proper mana^ment and by most easy processes, could' supersede the furnace in not
a few operations upon metals ; and that man^ operations with metals, which coold
scarcely be entertained under the old condition of things, might be placed in the
hands of a child, when electricity is employed as the agent
ELECTRO-METALLURGY. 89
PaUic attention was first directed to the important discovery bj a notice that
appeared m the Atheiutum of May 4, 1SS9, that Professor Jaoobi of St Petersbarg
had ** found a method of conyerting any line, however fine, engraved on copper, into
a relief by galvanic process^** Jacobi's own aoeonnt of the matter was that, while at
Dorpat, in Febrnary, 1837, prosecating his galvanic investigations, a striking phe-
oomenon presented itself, which fnmished him with perfectly novel views. Official
dades prevented his completing the investigation, thus opened ont to him, daring the
same year; and it was not until Octobers, 1838, that he communicated his dis-
coveiy, accompanied with specimens, to the Academy of Sciences at St Petersburg ;
an abstract of which paper was published in the Oerman News of the same place on
October 30 of the same year. And in a letter of Mr. Lettsom, dated February 5,
1839, the nature of the discovery is thus given in the following March number of the
AMmak of Electricity, Speaking of a recent discovery of Professor Jacobi's he says,
" Ue observed that the copper deposited by galvanic action on his plates of copper,
eoold by certain precauUons be removed fh>m those plates in perfect sheets, which
presented in relief most accurately every accidental indentation on the original plate.
Following up this remark, he employed an engraved copper-plate for his battery,
caosed the deposit to be formed on it, and removed it by some means or other ; he found
that the engraving was printed thereon in relief (like a woodcut) and sharp enough
to print frmn." This paragraph does not appear to have caught the eye of the
public so readily as the briefer note that appeared a couple of months later in the
On May 8, or four days after the appearance of the notice in the Atheiuntm^ Mr.
Thomas Spencer gave notice to the Polytechnic Society of Liverpool that he had a
commnnication to make to the society relative to the application of electricity to the
arts. He subsequently desired to communicate the result of his discoveries to the
British Association whose meeting was at hand ; but, for some cause, which does not
appear, the commui^cation was not made ; and it eventually was made public, as at
first proposed, through the Polytechnic Society of Liverpool, on September 12, 1839.
In the meantime, namely on Bfay 22, Mr. C. J. Jordan, referring to the notice in the
.^l/sAemnnn, wrote to the Mechanics* Magazine that, at the commencement of the
summer of 1838, he had made " some experiments with the view of obtaining im-
pressions from engraved copper-plates by the aid of galvanism.** His letter de«
scribing this process appears in the numl]«r for June 8. It occurred to him, fh>m
what he had gathered from previous experience, that an impression might be ob-
tained from an engraved surfsice ; and so it was, ** for on detaching the precipitated
metal, the most delicate and superficial markings, from the fine particles of powder
used in polishing to the deeper touches of a needle or graver, exhibited their cor-
respondent impressions in relief with great fidelity."
Mr. Spencer in lus communication^ besides noticing the fidelity with which the
traces on an original plate were copied, recorded the case of a copper-plate that had
become covered with precipitated copper, excepting in two or three places, where by
accident some drops of varnish had fallen; whence it occurred to him, and experiment
confirmed his conjecture, that a plate of copper might be varnished, and a design made
through the varnish with a point, and copper might be deposited upon the metal at
the exposed part, and thus a raised design be procured.
In the Philomiphical Magazine for December, 1836, Bfr. De la Rue, after describing
a form of voltaic battery, refers to the well-known condition on which the properties
of the battery in question mainly depend, that ** the copper-plate is also covered with
a coating of met^c copper, which is continually being deposited ; " and he goes on
to describe that ** so perfect is the sheet <^ copper thus formed, that being stripped
o«it, it has the counterpart of every scratch of the plate on which it is deposited.'*
Daniell himself, whose battery is here in question, noticed as he could not fail to
do in common with all who had employed his battery to any extent, the same pecu-
liarities ; but it does not appear that either he or De la Rue, or any one else, to whom
the phenomenon presented itself before Jacobi, Jordan, or Spencer, caught the idea of
its applicability in the arts. It would also appear that the impression came with the
greater vividness to the two latter ; for, while but little time seems to have been lost
to them in realising their idea, twenty long months elapsed between the time when
the ** perfectly novel views *' first presented themselves to Professor Jacobi, and the
time when his '^ well -developed galvanic production'* was communicated to the
Imperial Academy of Science. But, on the other hand, neither Mr. Jordan nor Mr.
Spencer appear, as far as we are aware, to have been so sensible of the importance
of the results to which they had arrived as to have taken any steps to secure them
aa an invention or to publish them, until their attention was aroused by the previous
publication of the successes of Jacobi.
Jacobi's '^Galvano-plastik,'* Smee's and also Shaw's "Electro-metallurgy,*' Walker*s
90 ELECTRO-METALLTIRGT.
" ElectrotTp* IfoDipalatioii,'' fonr well-known works on the sd1:ij«c( befbre ns, praotl
the different nsmea under vhieb the art is known ; uid from which Et is gatbertd
that metali mif become, M it were, pltutic ander the agency of galTanic eleclricilf,
■ud may be worked and moulded into form. Voltaie pairs are described in geneTml
tenns in the article on Ei.E(;rao-TELEOKAPBT. The particular TOltaic pair which ledlo
tho diBcoreries now before na, here requires special notice ; because, on the one band,
while in use for other purposes, it was the iostrument which first directed attenlioa
forcibly to the bduTiour of metals ander certain conditions of electric current ; and,
on the other hand, it baa been itself eztensively oaed in eleclmtj'pe operations.
Professor Dsniell first described his mode of arranging a Toltaic pair in the Pkiia-
taphical Traiuaclioiu for 1836. Fig. 695 shows one cell complete of Dujiell's com-
bination, which trotn its behaviour is called a constant battery, a is a cc^per vessel ;
B » rod of line, contained in a tube c of porous earthenware.
695 The liquid within the tube c it itdt and water, io which case the
cine is in its natural stale ; or, snlphnric acid and water, in
which case the xino is amalgamated ; the lstt«r arrangement being
the more active of the two. The liquid in the onier vessel a, coo-
•ista of crystals of mlphate of copper, diaaolved in water. Al c
is • perforated shelf of copper below the lurfnoe of the liquid,
DpoD which are placed spare crystals of sulphate of copper, which
o dissolve as requirrd, and serve to keep up the strength o( the
solution in proportion as the copper already there is eitmeted by
the voltaic action hereafter to be described, a and b are screws,
to which wires may be attached, in order to connect ap the cell
and coDTCj the current f^om it into any desired apparatus. Certain
chemical changes take place when this instrument is in action ;
oiygen from the water within the porons tube combines with
ainc, making oxide of zinc, which enters into combioation with
sulphuric acid, producing as a final result sulphate of sine; hydro-
gen is liberated ft^im water in the outer cell, and itself liberatH
oxygen from oxide of copper, and combines with it prodncing
water, and leaving copper free. As far as the metals are con-
cerned, line is consumed /root the rod b, at the one end, and copper is liberated
upon the plate A, at the other eod. These actions are slow and continuous ; and
the copper, as it is liberated atom by atom, appears upon the inner surface of the
cell; and after a tafficient quantity has been accumulated, may be peeled off or
removed ; when it will be found to present the marks and features of the surftce
from which it has been taken, and which, as we have already said, arrested the
696 attention of many into whose hands Ibis instrument fell. A slight
modification of the above arrangement gives v» a regular eleeUo-
type apparatus. The cell c in tbi^ arrangemeut (fig, 696), is of glass
or porcelain, or gutta percha, filled as before with a saturated aolutioa
of sulphate of copper, to which a tittle free acid is generally
added; it ia provided with a shelf or other means of suspending
cryatnls of snlphate of copper. A line rod i ia placed in a porous
tube p, OS already described; and m, the other metal of the voltuc
e pair, is suspended in the copper solution and connected with the
tine z by the wire w. The electric cnrrent now passes ; line is
consumed, as in fig. 695, but copper is now deposited on the metal
in fi'onC and back, and on as much of the wire to as may be in the
liquid ; or, if Mr. Spencer's precaution is taken of varnishing the
wire and the back of the metal m, all the copper that is liberated
will be accumulated on the ^e of m. If salt and water or very
weak acid water is contained in the porous tube p, and the iloc x
does not considerably exceed in size the metal n, the conditions will be complied
with for depositing copper in a oompacl regnline form.
It is obvious that, with this arrangement, m may be a mould or other form in
tnetal, and that a copy of it may be obtained iu copper. Fusible metal, consisting
of 8 perls of bismuth, 4 of tin, 5 of lead, and 1 of anlimany ; or S parts bismuth,
S tin, and S lead, is much used for taking moulds of medals. The ingredients aie
well melted together and mixed ; a quantity sufficient for the object in riev is
poured upon a slab or board and stirred together till about to set ; the film of dross
is then qnicklj cleared trom the surface with a card, and the cotd medal is either
projected upon the bright metal, or lieing previously fitted in a block of wood if
applied with a sudden blow. Moulds of wax or stearine Tanously combined, M
more recently and better io many cases, moulds of gotta percha, are appHeable to
many purposee. Bat, as none of these latter materiiJs conduct electricity, it ia m-
ELECTROMETALLURGY.
91
oessftry to provide tbem with a eondneteoos snT&ee. Plumbago or black lead \»
almoat imiTenallj employed fbr this parpo«e ; it is rubbed orer the sarfaoe of the
mould widi a piece of wool on a soft brash, care being taken to continue it as fkr as
to the coadiieting wire, bj which the mould is connected with the sine. With
moulds of solid metal, the deposit of copper commences throughout the entire sur-
ftce at once ; but, with moulds having only a film of plumbago for a conductor,
the action commences at the wire and extends itself gradually until it has been de-
veloped on all parts of the surface.
The nature of the electro-chemical decompositions that are due to the passage of
voltaic currents through liquids, especially through liquids in which metal is in cer-
tain forms contained, can be best understood by studying the arrangement that is
most commonly used in the arts, wherein the voltaic apparatus, firom which the
electric current is obtained, is distinct and separate from the vessel in which the
electro-metallurgical operations are being brought about Such an arrangement is
shown in fig 697, where ▲ is a Daniell's cell, as m fig. 695 ; and B a trough filled with
697
an acid solution of sulphate of copper ; m is a metal rod, on which the moulds are hung ;
and c a metal rod, upon which plates of copper are hung facing the moulds ; the
copper-plates are connected by the wire z with the copper of the battery cell, and
the moulds by the wire x with the zinc rod. The voltaic current is generated in the
ceU A, and its direction is from the zinc rod, through the solutions to the copper of
the cell ; thence by the wire z to the plates of copper c ; through the sulphate solu-
tion to Uie moulds m ; and thence by the wire x to the zinc rod. In this arrangement,
no shelf is necessary in the trough b for crystals of sulphate of copper to keep up the
strength of the solution ; for the natare of the electro-chemical decompositions is
such, that in proportion as copper is abstracted and deposited upon the moalds m,
other copper is dissolved into the solution from the plates c. Water is the prime
subject of decomposition. It is a compound body, consisting of the gases oxygen
and hydrogen, and may be represented by fig. 698, where /^^ 698
the arrows show the direction in which the current, by
the wire p, enters the trough b of ^. 697 by the plate of
copper c and passes through the water in the direction
shown, and leaves it after traversing the mould by the
wiren. Two a/onu of water o h and o' H',as bracketed
1 and 3, are shown to exist before the electric current
passes ; and two atoms, one ofwater h & ^bracketed I'),
and one of oxide of copper o c, exist after the action. On
the one hand an atom of copper c has come into the solation ; and, on the other hand,
the atom of hydrogen h', belonging to the second atom of water, is set tree and rises
in the form of gas. The explanation is to show that oxygen is liberated where the
current enters, and combines there in its nascent state with copper ; it would not have
combined, for instance, with gold or platinum. We might easily extend this sym-
bolical figure, and show how that, when free sulphuric acid is in the solution, the
oxide of copper on its formation combines with this acid to produce the sulphate of
copper required ; and how, when free sulphate of copper is present, the hydrogen,
instead of being freed in the form of gas, combines with oxygen of the oxide of cop-
per, and liberates the metal, which in its nascent state is deposited on the mould,
and produces the electrotype copy of the same. One battery cell is sufficient for
working in this way in copper ; it is increased in size in proportion to the size of the
object operated upon. And, although for small subjects, such as medals, a vertical
arrangement will act very well ; for large objects, it has been often found of great
ELECTRO-METALLTTRGT.
kngEment, placing the moald beoetiUi the ctqiper-
. ^ . idU soluCioQ in the vertical arnuigemeDt U not
without its effect upon the nature of the depocit, both on its character aud ita relative
thicknen. This has been in some iaMauee* obviMed, and the advantage of the ver-
tical method relained bf keeping the lolution in motion, atber by atining or by a
contiDDDOB flow of liquid.
We have deicribed principally Daniell's battery aa the generating' cell in Electro-
metallnrgical operalioni ; but Mr. Smee'i more limple arrangciDent of platiuiied
silver and linc. eieiied with dilated gulpharic acid, hat been found in practice more
Fig. G99 is aSmee's cell ; a vessel of wood, glass, or earthenmre, eontains diluted
sulphuric acid, one in eight or ten, a pUtinised silver plate a, soetuned b; a piece <^
e99 wood ID, with a pUte of line z E on each tide, so as tn turn to useful
account both sides of the silver plate. The zinc places are connected.
by the binding screw b. Platiuization consists in applying plati-
num in fine powder to the metallic Barfu:c. When hydrogen is
liberated by ordinary electric action upon a sarftce so prepared, it
has no tendency to adhere or cling to it; but it at once rises, and in
fact gets out of the way, so that it never, by its presence or linger-
ing, interferes with the prompt and ready continuance of the electrie
action ; and in this way, the amount of aapply is well kept up.
PlslinizatiOD is itself another illnstratioo of working in metal bj
electricity. A few crystals of chloride of platinuia are disaolvt^
in diluted sulphuric acid. A voltaic carrent is made to enter this
solution by a plate of platinum and to come out by a silver plate.
Two or three DbuieU's or Smee's cell* are necessary for the ope-
' ration. The chloride of plalinum is decomposed, and the metal is
deposited upon the siNer plnte ; not, however, in the regaline
compact form, as in the case of copper, but in a state of black powder in no way
coherent. This aCTords also an illustrstion of the different behcvioiir of meIkU
under analogous circnmsCances. Copper is of all metals the most manageable ;
platinum is among the more nnmsnageable.
Mr. C. V. Walker has, with groat advantage, sabstitnted graphite for silver. The
material is obtained from gas retorts, and is cut into plates a quarter of an inch thick,
or thicker, when plates of a larger size are cut. He platinizes these plates in the
Qsual way as above described, and deposits copper on their upper parts, also by elec-
trotype process, and solders a copper slip to the electrotype copper, in order to make
the necessary connection.
With the exception of silver and gold, copper is the metal which has been most
eztenaively worked by these processes.
Seals are copied by obtaining impressions in sealing-wax, pressing a warm wire
into the edge for a connection ; rubbing blacklead over the wax to m^e the inrface
conducteous ; &stening a slip of zinc to the other end of the wire t wrapping the line
in brown paper, and putting the whole into a tnmbler containing sQlpbate of copper,
B little salt-water having been poured into the brown paper celL
FLAsTEit or Pabis MsDAi-uatiB may be saturated witli wax or stearioe, and then
trested, if small, like seals ; if large, in a distinct trough, ss in j!^. 697. In [bis case
the copy is in intaglio, and may be used as a mould for obtaining the facsimile of the
cast. More commonly, the cast is saturated with warm water, and a mould of it
taken in wax, stearine, or gutta percba. This is treated with blacklead, and in other
respects the same as seals.
WooDcDTB are treated with blacklead, and a copper reverse is deposited npon
them, Tbis is used as a mould to obtain electrotype duplicates, or as a die for
striking off duplicates.
Stehbotvpe Plates are obtained in copper by taking a plaster copy of the type,
treating it plaster fashion, depositing a thm piste of copper upon it, and giving
Btreug^ by backing up with melted lead.
Old Brasses may be copied fay the intervention of plaster.
Enbdbsed cards OB PAPBB may be copied by first saturating with wax and then
using blacklead.
Fbuit may be copied by the intervention of moulds, or may be covered with
COTper. Leaves, twigs, and bhancbes may have copper deposited upon them.
Leaves and flowers are famished with a conducting surface by dipping them into
a lolotion of phosphorus in biaulphurel of carbon, and then into a solntiou of nitrate
of silver. Silver is thus released in a metallic state upon their surface.
ELECTRO-METALLURGY. 98
Flabtbk Buns, ftc, haye been copied in copper, by first depositing copper on
the plaster prepared for this operation ; when thick enough, the original bnst is de-
stroyed, the copper shell is filled with sulphate of copper, as in ^.697, and copper
is deposited on its inner sor&ce till of sufficient thickness s the outer shell is then
remoTcd.
Tubes and yessels of capacity do not appear to have been profitably multiplied
by electrotype.
Pultes haye been prepared for the enoratsb to work on by depositing copper
OD polished copper-plates, and remoTing the deposits when thick enough.
For the multiplication of enobatbd cofpeb plates, the electrotype process has
been yery extenslYely adopted. A reyerse of the plate is first obtained by the depo-
sition of copper ; this seryes as a mould, from which many copies of Uie original
plate are obtained by depositing copper upon it, and then separating the twa
The mode practised by the Duke of I^uchtenberg is to print from an engrayed plate
on yery thin paper with a mixture of resin of Damara, Kd oxide of iron, and essence
of turpentine. While the impression va wet, the paper face downwards is prMsed
upon a polished plate of copper. MThen dry the paper is washed away, and Uie im-
pression remalus. An electrotjrpe copy from this is obtained in intaglio, and is fit
for the use of the printer.
GALyANOOBApHT is a picture drawn originally in yamish on the smooth platen
and then treated in a similar way to the aboye.
The PLATES on rollers used by cauoo pbihtbbs haye been multiplied like en-
grayed plates.
Gltpboqbapht is a name giyen by Mr. Palmer to his process. He blackens a
fiiir copper-plate with snlphnret of potassium, coyering it uniformly with a coating of
wax and other things, then draws the design through me wax with fine tools. From
the plate thus prepared, an electrotype is taken in the usual way, and is backed up
and mounted as an electro-glyphic cast to print from as from a wood block. For a
stereo^yphic cast to work from as a stereotype plate, a plaster copy is taken of the
original drawing, the high lights are cut out, and then an electrotype copy is made.
Elbctbo-timt is done by drawing with wax or yarnish any design on a fair
copper-plate, and making an electrotype copy for the printer's use.
^BN-LBAYES, &C., are copied by being laid on a sheet of soft gutta percha, pressed
into the sur&ce by a smooth plate to which pressure is applied, and then removed in-
order to subject die gutta percha mould to the electrotype process. This is Natubb
Pbintino, which see.
MM. Aner and Worring haye copied lace, embboidebt, flowers, leaves of trees^
entire plants, fossils, insects, &c., in their natural relief, by laying the objects upon a
plate of copper, after having soaked them in spirits of wine and turpentine so as to fix
them. A plate of clean lead is laid oyer, and, on being pressed, an intaglio copy is
produced on it of the object. From this an electrotype is obtained.
Undebcut medallions, &c., are copied in elastic moulds made of treacle and
glue in the proportions of 1 to 4. Masks and busts may also be obtained in such
moulds.
£lec?tbo-cloth was made by saturating the fibre of canvass or felt, making it con-
ducteons in the usual way *, it was proposed in place of tarpaulins as a water-tight
cover. •
Rbtobts and cbucibles, &c., of glass or porcelain, have been successfully
.coated with electrotype copper by first varnishing or otherwise preparing the snrfitoe
to retain the black lead, and then treating them as usuaL
SoLDEBiNO COPPBB surfaccs has been accomplished by galvanic agency. The ends
to be united are placed together in the solution of sulphate of copper, and connected
with the battery as for ordinary deposition. Parts not included in the process are
protected off by varnish ; copper is Uien deposited, so as to unite the separate pieces
into one.
Ibon may be coated with coppeb. But here a new feature comes into view.
Sulphuric acid leaves the copper of the sulphate, combines with iron and deposits
copper on its surfoce without the aid of the yoltaic apparatus. The iron surface is im-
perfectly coyered with copper, no firm perfect deposit occurs. In order to obtain solid
deposits <k copper on iron, it is necessary to use a solution that has no ordinary
chemical reaction upon iron. Cyanide of copper is used, which may be obtained by
dissolying sulphate of copper in cyanide of potassium. This solution requires to be
raised to and retained at a temperature not greatly below 200^, in order to give good
results.
Electbo-zincino is applied to surfaces of iron, in order to protect them fWmi
corrosioD» A solution is made of sulphate of zinc, which is placed in a trough b»
94 ELECTRO-METALLURGY.
fig, 697. Two or three battery cells are required. The iron to be aineed if eomieeted
with the ainc end of the batterj, and a plate of ainc with the copper end.
Voltaic brass does not appear to haTe been obtained in a solid distinet Ibnii,
but has been snccessAiUy produced as a coating upon a copper sar&oe. Sepvate
solutions are made of sulphate of copper and of sulphate of sine in cyanide of
potassinm. The two solutions are then mixed, and placed in a decomposing trongli.
Two or three cells of a battery are used, and a brass plate connected with the copper
end. An electrotype copper medal or other prepared surface is connected with the
sine. Brilliaot and perfiMst brass soon appears, and will deposit slowly for some
hours ; but alter a while, the character of the solution changes, and copper appears in
place of brass.
This hasty glance at the leading applications of this art will giye an idea of its
utility. It alM> comes into play in cases where least suspected. Pins were tinned
by electrotype long before the art was known. Brass pins are thrown into solution
of tin in cream of tartar, and are unchanged ; but when a lump of tin is thrown
among them, a Toltaic pair is formed, and tin is deposited on all the heapw Any
stray pins detached from the mass, escape the influence. Space would fail us were
we to go through the list of crystalline and of simple bodies formed by these pro-
cesses ; as for instance, octahedral crystals of protoxide of copper ; tetrahedral
crystals of proto-chloride of copper; octahedral crystals of sulphide of silTcr;
crystals of subnitrate of copper ; bibasic carbonate of copper, and others too nnmerooa
to name, have all been formed by slow Toltaic actions. The alkaline metala, po-
tassium, sodium, &C., were first obtained b^ Davy in the galvanic way; magnesium,
barium, aluminium, calcium, &c., are obtained by M. Bunsen by operating upon the
chlorides of these metals either in solution or in a state of fusion.
Electro-etchino is produced at the place where the current enUn the decom-
posing trough, as at the copper-plates c of jig. 697. A plate of copper is prepared as
if for the graver ; its face is then covered with an etching ground of asphalte, wax,
black pitch, and burgundy pitch ; and its back with Tarnish. The design is then
traced through the etching ground with a fine point ; the plate is then placed in the
trough B, containing either sulphate of copper or simply diluted sulphuric acid, and
connected with the copper of the battery. After a few minutes it is removed, and
the fine lines are stopped out with varnish ; it is then replaced, and again, after a
few minutes is removed, and the darker shades are stopped out ; the parts still ex-
posed are again subjected to the action, and the etching is complete. When the
ground is removed, the design will be found etched upon the copper-plate ready for
the printer.
Dagctkrreottpe etching is a delicate operation, and requires much care. The
solution employed by Professor Grove was hydrochloric acid and water in equal
parts, and a battery of two or three cells.
Platinized silver is used in face of the daguerreotype, instead of copper. The result
comes out in about half a minute. An oxy-chloride of silver is formed, and the
mercury of the plate remains untouched.
A Photo-oalvano-graphic Company has been formed in London for carrying
out the process of Paul Pretsch. He makes solutions of bichromate of potash in glue
water, or in Mlntion of gelatine, instead of in pure water. He then treats the glass or
plate with these, and in the usual way takes a picture. He washes the gelatine pictoie
with water, or solution of borax or carbonate of soda, which leaves the picture in
relief; when developed, he washes with spirits of wine, and obtains a sunk design.
The surfaces thus prepared, or moulds made from them in one or other of the modes
already described, are placed in a galvano-plastic apparatus for obtaining an en-
graved plate from which to print See Photo-oalvanographt.
The Duke of Leuchtenberg prepares a plate for etching by leaving the design on
the ground, and removing the ground for the blank parts. When his electrotype
operation is complete, the design is in relief instead of being in intaglio as in ordi-
nary etching.
MbtaIiLo-cbromes consist of thin films of oxide of lead, deposited sometimes oa
polished plates of platinum, but most commonly on polished steel plates. The colours
are most brilliant and varied. Nobili is the author of the process.
A saturated solution of acetate of lead is prepared and placed in a horisontal
trough. Three or four battery cells are required. A steel plate is laid in the
acetate of lead with its polished surface upward, and is connected with the copper of
the battery. If a wire is connected with the zinc end of the battery, and held over
the steel plate in the solution, a series of circles in brilliant colours, arise from the
spot immediately beneath the wire, and expand and spread, like the circles when a
stone is thrown into a pond. Silver-blond is the first colour ; then fiiwn-colottr, fol-
lowed by the various shades of violet, and indigocs and blues ; lake, bluish lake,
ELECTRO-METALLUBGY.
95
green and orange, greeniah Tiolet, and pasaisg tbroagb reddiah yellaw to roae-lake,
which JB the hat colonr in the aeries.
According to the shape of the metal by which the carrent enters — be it a point,
a allp, a crosa, a concave, or a convex disc — so is the form of the coloared ngnre
▼aried. And i^ in addition to this, a pattern in card or gutta percha is cut out and
interposed between the two aur&ees, the action is intercepted by the portions not
removed, and the design is produced on the steel plate, in colours, that may be
greatly varied, according to the duration of the experiment The different coloura
are due to the different thicknesses of the thin films of peroxide of lead.
M. Becquerel propoaed the deposit of peroxide of lead, and also the red peroxide of
iron, for protecting metals from the action of the atmosphere. For the latter, proto-
sulphate of iron is dissolved in ammonia solution, and operated upon by two or three
batteries.
The most important application of electro-metaQurgy in the arts has been for
FLATDio and gujdxmo, which is most extensively carried on both at home and abroad.
Results that were unattainable, and others attainable only at great cost, are readily
produced by this mode of manipulating. The liquids most in use are the cyanide
solutions, first introduced by Messrs. Elkingtons. They are prepared in various
ways. Cyanide of potassium is added carefully to dilute solution of nitrate of silver ;
and the white deposit of cyanide of silver is washed, and then dissolved in other
cyanide of potassium ; or lime water is added to the nitrate aolution, and the brown
deposit of oxide of silver is washed and, while moist, is dissolved in cyanide of
potassium; or common salt is added to the nitrate solution, and the white deposit of
chloride of silver is washed and dissolved in cyanide of potassiuuL Or a solution of
cyanide of potassium is placed in the trough n^fig. 697 ; and the current from three
or four cells is passed into it from a silver plate at c, which combines with and is
dissolved into the liquid, converting it into a cyanide of silver solution. To prevent
silver being abstracted by deposition at m, as the current leaves the trough, the
metal at m is placed within a porous cell of cyanide solution, so as to limit the action.
Gold solution is obtained by dissolving the anhydrous peroxide of gold in cyanide
of potassium, or by treating chloride of gold with cyanide of potassium, or by using
a gold plate and a voltaic current with a solution of cyanide of potassium in the same
way as described for silver *, and allowing the action to continue until the solution is
sufficiently strong of gold. With these solutions electro-plating and gilding are
readily accomplished. There are other solutions more or less valuable, which will be
found in the books that treat upon the subject.
Fig. 700 shows a single cell arrangement for plating. The zino is outside, and ia
bent to embrace both sides of the porous celL The article to be plated ia within thia
cell ; because, being the vessel of smaller capacity, less of the more valuable silver
solution is required, and there is less of loss or waste. The same holds good in a
greater degree of gold. In a few minutes, the article is covered with silver. If a few
drops of sulphuret of carbon are added to the silver solution, the silver is deposited
bright. Gold does not come down quite so rapidly as silver.
Except for mere experiment, these operations are better accomplished and with
leas waste by using distinct batteries, as a, >f^. 701, the solution of gold or silver being
in a distinct trough 6, plates of silver or gold, as the cases may be, being suspended
in ftront of the article to be coated. One or two cells, acconUng to the results re-
quired, are used for plating ; and three or four for gilding. But gilding is never so
ELECTRO-METALLUEGT.
arrangement for operationi on a saiall scale. The Te»e1 a £, conlsinuiK the gold
Bolutlan, resti otct a anmll itore or apirit-lunp. The objects to be gilt are aupeodtd
bf irirei to the couductiug rod d, in connection with the zinc end of the battery ; and
the gold wire or plate cii connected with the other end. Atemper«ture of from 100° U
!00°ii desirable ; the higher Cemperaturea require fewer batteiy cells ; with the highest,
one will ufflce. The solulion of coune eraporalei onder the influence of heat; and
distilled water mnit be added to supply the loss, before each ftcsh operation.
Plaling and gilding is successfullj and, in point of economy, advantagtonslj
carried an at Birmingham, in more thiLn one manafactorr, by means of magneto-
electricity. In the article on Eleotbic-Teleobaphi will be found a description of this
farm of electric force ; and the means by which it is produced. An electro-magnet ii
(et in motion in fh>nt of the poles of a permanent magnet, in such a manner that tbe
soft iron core of the electro-magnet becomes alternately a magnet and not a magnet ;
in the act of becoming a magnet, it iBi»e> up a corrent in one direction in the aire
with which it is wound; in Uie act of ceasing to be a magnet, it raises ap a cnrreat in
the rtrerte direction. The ends of the wire are ledaway and iniukled. Theinttm-
ent i* fitted with a wmnnutaloi, so adjusted that it collecli the currents tro
id* of the wire, and goidea them in a uniform direction into the Teasel that eo
le Mhilion and articles to be gilded or phited. In practice, a tingle tnaoliint at
ELECTRO-MOTIVE ENGINES. 97
of many electro-magnets grouped together, and many powerful magnets for exciting
them ; by -which means a continuous flow of a large amount of electricity is ob-
tained. Fig, 703 is an illustration of such an arrangement as adapted by Mr. Woolrich :
a aaa are four clusters of permanent steel magnets, seen from above ; b bb b bis the
frame-work of the machine \ c c c c are four bars of soft iron, wound with large sixe
insulated copper wire ; </ is a circular disc, on which they are mounted, and which
rotates on a Tertical axis, of which f shows the upper end ; e is the commutator,
from which two wires are led off to the solution to be operated upon. The permanent
magnets are U shaped ; one pole only of each bundle is yisible ; the other is beneath
the disc di, and its freight of electro- magnets c c, &c. The axis is set in rotation by
a strap passing over the drum of a shaft of the steam-engine, that does the ordinary
work in a factory ; and the disc carries the electro-magnets between the poles of the
permanent magnets, and exposes them to the most fi&vourable action of these poles.
The number of coils and magnets vary in proportion to the work required. By this
arrangement, not only does each coil pass under the influence of many magnets, but
each magnet acts successively on many coils ; and a proportionate supply of electri-
city is the result — C. V. W.
ELECTBO-HOTIVE ENGINES. The following remarks on this subject are an
abstract of a communication read by the editor to the Inatitution, of Civil ^ngineers^
for which they awarded him their Telford Medal. '
Numerous electro-magnetic machines have been made, but a few only of these
Te«|uire to be described. In 1832, Sal vatore Dal Negro published an account of the at-
tempts made by him in this direction. As Dal Negro's engine was of a very simple
and effective kind, the Professor's description of it may be quoted : — **As I had been
soccessfbl in producing temporary magnets of very great power, with very small elec-
tro-motors, I endeavoured to apply this power to moving noachinery. I will now
briefly state by what means I endeavoured to set a lever in motion. I first used a
magnetic steel bar, placed vertically between one end of a temporary magnet The
bar vibrated from the attractions and repulsions which took place between its north
pole and the north and south poles of the electro-magnet. In the same way a motion
may be effected in a horizontal plane. I also set in motion a similar bar, by allowing
a piece of iron, set free from the magnet at the moment when its power became « o
to fall on one of its ends, after this it was immediately re-attracted. This can be ef-
fected in two ways : the one may be employed when a quick motion is to be produced
and the second when a greater force is wanted ; in the first case the weight falls only
just out of the power of the magnet's attraction, and the instant the weight has fallen
upon the bar, or lever, it is re-attracted b^ the magnet that the action may be re-
peated : It is always small in comparison with that which the magnet cannot support
whilst in contact. In the second case the whole weight which the magnet can carry
is employed, and use is made of the force which draws it to the magnet" Upon this
was founded several other attempts, particularly one by Dr. Schulthess, who was so
satisfied with the result, that he wrote in 1833 : — " If we consider that electro-magnets
have already been made, which were capable of carrying 20 cwts., and that there is
no reason to doubt that they may be made infinitely more powerful, I think I may
boldly assert, that electro-magnetism may certainly be employed for the purpose of
moving machines." Professor Botto of Turin, also employed ** a lever put in motion
(in th^ manner of a metronome) by the alternating of two fixed electro-magnetic
cylinders, exerted on a third movable cylinder, connected with the lower arm of the
lever, the upper part of which maintains a metallic wheel, serving in the ordinary
way, as a regulator in a continuous gyratory motion." It will be evident to any one
who has observed the motion of manv of the electric clocks, that this is in several
respects similar to the pendulous motions adopted.
In 1835, Professor .lacobi, of St Petersburg, published an account of his experi-
ments, which were carried out on a large scale, regardless of cost, at the expense of
the Emperor Nicholas. His first idea was to employ the attractive and repellant
powers of magnetic bars, so that he might obtain an advancing and receding motion,
which could be easily changed into a continuous circular motion. A great many
machines have been made upon this principle ; but Jacobi, alone, as far as can be
learned, has pointed out the true cause of their failure. *' We know," he says, ** the
ill effects of shocks in the movements of machines, but there is here, another incon-
venience which IS not simply mechanicaL The soft iron, by these repeated shocks
and vibrations, gradually acquires at the surface of contact the nature of steel ; there
will be a considerable permanent magnetism, and the transient magnetic force which
alone produces the movement, will be weakened in proportion. A number of ex-
periments, which I have made upon the magnetic force of a bar of soft iron, bent
into a horseshoe form, has shown me the great disadvantage of often repeated shocks,
proceeding firom the sudden contact of the armature."
Vol- II. U
98 ELECTRO-MOTIVE ENGINES.
Jacobi, finally setting aside all oscillating motions, prodnced a machine giving conti-
nuous circular motion, by fixing eight electro-magnetic bars on a disc, movable round an
axis—and eight fixed bars similarly arranged upon a fixed platform. The arrange-
ment of the bars admitted of mach variety, provided it was exactly symmetrical, uid
that it allowed the poles to approach each other as nearly as possible. Arrangements
were made, with much ingenuity, by which the poles of the magnets were inverted
directly, and so that that inversion should take place precisely at that point where
the bars were opposite each other. One hundred and forty-four inversions in the
second were readily effected, and Jacobi declared it would be easy with his apparatus
" to change, or to completely interrupt, the electric current, one thousand, or more,
times in a second/'
A machine constructed upon this principle was, at the desire and at the cost of an
Imperial Commission, put on board a ten-oared shallop, equipped with paddle-wheels,
to which the electro-magnetic engine communicated motion. The boat was 88 feet
long, and 7^ feet in width, and drew 2^ feet of water. In general, there were ten or
twelve persons on board, and the voyage on the Neva was continued during several
entire days. By these experiments Jacobi was led to the conclusion, that a battery
of 20 square feet of platinum would produce power equivalent to one horse ; and tlie
vessel went at the rate of four miles an hour. In 1839, Jacobi tried another experi-
ment, with a battery of 64 platinum plates, each having 36 square inches of sur&ce;
when the boat, with a party of 14 persons on board, went against the stream at the
rate of 3 miles an hour.
In 1837, Mr. Thomas Davenport, of the United States, constructed a rotary engine,
in which permanent and electro-magnets were employed. Mr. Taylor, in 1839,
patented an electro*magnetic engine, both in America aud in this country, the prin-
cipal novelty in which was, that instead of changing the poles of the magnets, the
electric action was, at fixed rapid intervals, entirely suspended. In 1837, Mr. David-
son, of Edinburgh, constructed an engine, in which he produced motion by simply
suspending the magnetism, without a change of the poles. Mr. Robert Davidson
placed an electro-magnetic locomotive on the Edinburgh and Glasgow Railway ; the
carriage was 16 feet long, and 6 feet broad, and weighed about 5 tons. All the
arrangements appear to have been very complete, but when put in motion on the
rails, It was not possible to obtain a greater speed than four miles an hour.
Professor Page's electro-magnetic engine was for some time looked upon as a
triumph. The fundamental principle of it is thus described : *' It is well known
that when a helix of suitable power is connected with the poles of a battery in action,
an iron bar, within it, will remain held up by the induced magnetism, although the
helix be placed in a vertical position ; and if the bar is partly drawn out of the helix
by the hand, it goes back with a spring, when the hand lets go its hold. This power,
»-the action of the helix upon the metallic bar within it, — is the power used in Page's
engine." Professor Page exhibited one of his engines, of between 4 and 5 horse-
power, at the Smithsonian Institution ; the battery to operate with being contained
within a space of 3 cubic feet. It was a reciprocating engine of 8 feet stroke* and
the whole, including the batter}', weighed about one ton. Professor Page stated, that
the consumption of 3 lbs. of zinc per day would produce one horse-power. This
statement requires further investigation.
Many similar attempts have been made, to construct effective machines 'to be
moved by the power of the voltaic battery. Among others, Mr. Henley constructed
an electro-magnetic engine of considerable power, for Mr. Talbot, and another for
Professor Wheatstone. In these there were manv ingenious mechanical arrange-
ments, invented to overcome some of the difficulties hitherto encountered ; but the
physical conditions were similar to those already described. Mr. Talbot's engine
was 3 feet 6 inches long, and 2 feet 6 inches wide ; when excited by a Grove's
battery, consisting of four cells with double plates of zinc, 9 inches by 6^ inches,
platinum plates 9 inches by 5^ inches, excited by diluted sulphuric acid in the pro-
portions of 1 to 4, and concentrated nitric acid, it drove a lathe, with which was
turned a gun-metal pulley 5 inches in diameter ; but in three quarters of an hour the
battery was quite exhausted.
Mr. Hjorth, a few years since, exhibited in London a large machine, constructed
somewhat on the principle of Page's ; this, however, fkiied to produce any great me-
chanical effect, and it appears to have been abandoned. Dr. Lardner stated, in 1851,
that M. Gustave Froment,of Paris, was using, with much advantage, an electro-mag-
netic engine in his workshops for turning lathes, planing machines, &c. Its use,
however, appears to have been abandoned, on account of the great cost of the battery
power.
Haukel and Fessel, on the Continent, the Rev. James William M'Gauley, Dr.
Kemp, and others, in Great Britain, have, at different times, excited much attention
by the ingenious machines which they have constructed.
ELECTRO-MOTIVE ENGINES. 99
Notwithstanding these numeroiis trials, and, connected with them, an almost infi-
nite amount of experiment, it does not appear, that an j satisfactory explanation has
ever been given of the causes which have led to the abandonment of the idea of em-
ploying electricity as a motive power. It was mainly with the view of directing atten-
tion to these canses, that the essay read was written.
Electro-magnetism undoubtedly affords an almost unlimited power. An electro-
magnet may be constructed which shall have a lifting power equal to many tons.
It is probable, that there are limits beyond which it would not be possible to increase
the power of electro-msgnets ; those limits have not yet been reached ; but supposing
them to be attained, there is nothing to prevent the multiplying of the number of
electro-magnets in the arrangements. It may be stated, in connection with this part
of the subject, that from experiments made with Hearder's magnetometer, it appears
that the development of magnetism in iron observes some special peculiarities. These
may be thus stated : — With the same electro -magnet there is, as the voltaic pairb in
the battery are increased, a gradual increase of magnetic force. With from one to
seven elements there appears an average excess of 31 lbs. ; after this point, with the
increase of batteiy power, by the addition of pair after pair of sine and platinum
elements, the production of power bears a decreasing ratio to the power employed,
and at last, the addition of five elements was not found to produce an increase of ef-
fect equivalent to the value of one element In all experiments, therefore, on elec-
tro-magnetic machines, the experimentalist has first to determine the utmost power
which the soft iron is capable of assuming, in relation to, — 1st. The number of coils
of wire on the iron ; and 2nd, the number of elements employed in the exciting
source — the voltadc battery. The length of the iron and its thickness are also points
demanding special considerations ftom the constructor of an electro-magnetic machine.
There remains now to examine the production of the power, Electro- Blagnetism.
The eleetro-mechanician is dependent upon his battery, in the same way as a
steam engineer is dependent upon his fire and his boiler, for the production of me*
cbanical effect.
Voltaic batteries vary in their effects, and hence arise statements which differ
widely from each other, as to the result obtained, by the destruction (? change of
form) of a given quanti^ of metal in the battery.
Dr. Botto states, that 45 lbs. of zinc, consumed in a Grove*s battery, are sufficient to
work one-horse power electro-magnetic engine for twenty-four hours.
Mr. Joule says the same results would have been obtained, had a Daniell*s battery
been used, by the consumption of 75 lbs. of sine
It is impossible, on the present occasion, to enter into the theory of the voltaic
battery, or to describe the varieties of arrangescent which have been adopted for gene-
rating (developing) electrical force in the form of a current, with the greatest effect,
at the smallest cost.
On this point the evidence of Jacobi may be quoted : — " With regard to the
magnetic machine, it will be of great importance to weaken the effects of the counter
current, without at the same time weakening the magnetism of the bars. It is the
alternate combination of the pairs of plates in the voltaic pile, which permits us to
increase the speed of rotation at will We know the magnetic power of the current
is not sensibly augmented by increasing the number of the pairs of plates, but the
coanter current is considerably weakened by its being forced to pass through a great
many layers of liquid. In fiict, on using twelve voltaic pairs, each, half a square
foot, instead of four copper troughs, each with a surfiice two square feet, which I
had hitherto used, the speed of rotation rose at least 250 or 300 revolutions in a
minute."
Mechanical force, whether obtained. in the form of man-power, horse-power,
steam-power, or electrical-power, is the result of a change of form in matter. In the
animal, it is the result of muscular and nervous energy, which is maintained by the
due supply of food to the stomach. In the steam-engine, it is the result of vapour
pressure, which is kept up by the constant addition of fuel to the fires, under the
boilers. In the magnetic machine, it is the result of currents circulating through
wires, and these currents are directly dependent upon the chemical change of zinc
or of some other metal in the battery. Then,
Animal power depends on food.
Steam power depends on coal.
Electrical power depends on zinc.
An equivalent of coal is consumed in the furnace — that is, it unites its carbon
with oxygen to form carbonic acid, and its hydrogen with oxygen to form water,
and during this change of state the quantity of heat developed has a constant relation
to the chemical action going on.
H 2
100 ELECTRO-PLATING AND GILDING.
Mr. Joule has proved hy a series of most satisfactory experiments, that : ** The
quantity of heat capable of increasing the temperature of a pound of water by one
degree of Fahrenheit's scale is equal to, and may be converted into, a mechanical
force capable of raising 838 lbs. to the perpendicular height of one foot.**
Mr. J. Scott Russell has shown that in the Cornish boilers, at Huel Towan and the
United Mines, the combustion of one pound of Welsh coal evaporates of m-ater, from
its initial temperature, 10*58^ and 10'48^ rt^pectively. "But,** says Mr. «loule, '*we
have shown that one degree is equal to 838 lbs. raised to the height of one foot
Therefore the heat evolved by the-combustion of one pound of coal is equivalent to the
mechanical force capable of raising 9,584,306 lbs. to the height of one foot, or to
about ten times the duty of the best Cornish engines."
Such are the conditions under which heat is employed as a motive power. An
equivalent of zinc is acted on by the acid in the cells of the battery, and is oxidised
thereby. In this process of oxidation a given quantity of electricity is set in motion ;
but the quantity available for use, falls very far below the whole amount developed
by the oxidation of the zinc. The electricity, or electrical disturbance, is generated
on the surface of the zinc ; it passes through the acidulated fluid to the copper plate
or platinum plate, and in thus passing from one medium to another, it has to overcome
certain mechanical resistances, and thus a portion of the force is lost. This takes place
in every cellof the voltaic arrangement, and consequently the proportion of zinc which is
consumed, to produce any final mechanical result, is considerably greater than it should
be theoretically.
Joule gives as the results of his experimAts, the mechanical force of the current
produced in a Danieirs battery as equal to 1,106,160 lbs. raised one foot high, per
pound of zinc, and that produced in a Grove's battery as equal to 1,843,600 lbs. raised
one foot high, per pound of zinc.
It need scarcely be stated, that this is infinitely above what can be practically ob-
tained. A great number of experiments, made by the Author some years since,
enabled him to determine, as the mean average result of the currents, produced bj
several forms of battery power, that one grain of zinc, consumed in the battery,
would exert a force equal to lifting 86 lbs. one foot high. Mr. Joule and Dr. Scoresby
thus sum up a series of experimental results : ** Upon the whole, we feel ourselTes
justified in fixing the maximum available duty of an electro-magnetic engine, worked
by a Danieirs battery, at 80 lbs. raised a foot high, for each grain of zinc consumed."
This is about one-half the theoretical maximum duty. In the Cornish engines, doing
the best duty, one grain of coal raised 143 lbs. one foot high. The difference in the
cost of zinc and coal need scarcely be remarked on. The present price of the metal
is 35/. per ton, and coal can be obtained, including carriage to the engines, at less
than U. per ton ; and the carbon element does two- thirds more work than can possi-
bly be obtained from the metallic one.
By improving the battery arrangements, operators may eventually succeed in
getting a greater available electrical force. But it must not be forgotten, that the
development of any physical force observes a constant law. Whether in burning coal
in the furnace, or zinc or iron in the battery, the chemical equivalent represents the
theoretical mechanical power. Therefore, the atomic weight of the carbon atom being
6, and that of the zinc atom being 32, it is not practicable, under the best possible ar-
rangements, to obtain anything like the same mechanical power from zinc which can
be obtained from coal. Zinc bums at an elevated temperature ; in burning a pound
of zinc there should be obtained, as heat, the same amount of mechanical power which
is obtained as electricity in the batteiy. The heat being more easily applied as t
prime mover, it would be far more economical to bum zinc under a boiler, and to use
it for generating steam power, than to consume zinc in a voltaic battery for generating
electro-magnetical power.
ELECTRa PLATING AND GILDING IRON. Professor Wood, of Springfield,
liassachusetts, in a paper, which he has communicated to the Scientific Americanj recom-
mends the following as useful recipes for the electro-metallurgist He says, ^ I believe it
is the first time that a solution for plating direct on iron, steel, or Britannia metal has been
published. In most of the experiments I have used Smee's battery ; but for depositing
brass I prefer a battery fitted up as Grove*s, using artificial graphite — obtained from
the inside of broken coal-gas retorts — in the place of platinum. With one large cell
(the zinc cylinder being 8x3 inches, and excited with a mixture of one part sulphuric
acid and twelve parts water, the graphite being excited with commercial nitric acid)
I have plated six gross of polished iron buckles per hour with brass. I have also
coated type and stereotype plates with brass, and find it more durable than copper-
facing."
To prepare Cyanide of Silver, — 1. Dissolve 1 oz. of pure silver in 2 oz. of nitric
acid and 2 oz. of hot water, after which add 1 quart of hot water. 2. Dissolve
ELECTRO-TELEGRAPnY. 101
5 oz. of the cyanide of potassiam in 1 qoart of water. To the first prei>aration add
by de^ees a email portion of the second preparation, until the -whole of the tiWer is
precipitated, which may be known by stirring the miztnre and allowing it to settle.
Then drop into the clear liquid a very small quantity of the second preparation fVom
the end of a glass rod ; if the clear liquid is rendered tnrbid, it is a proof that the
-whole of the silver is not separated ; if^ on the other hand, the liquid is not altered, it
is a proof that the silver is separated. The clear liquid is now to be poured off, and
the precipitate, which is the cyanide ef silver, washed at least four times in hot
water. The precipitate may now be dried and bottled for use. To prepare Cffanide
of Gold — Dissolve 1 oz. of fine gold in i'4 oz.' of nitric acid and 8 oz. of muriatic
acid ; after it is dissolved add 1 quart of hot water, and precipitate with the second
preparation, proeeeding the same a» for the cyanide of silver. To prepare Cyanuiee
of Copper and Zine, — ^For copper, dissolve I: oz. of sulphate of copper in 1 pint of hot
water. For zinc, dissolve 1 oz. of the sulphate of zinc in 1 pint of hot water, and
proceed the same as for cyanide of silver. The electro-plater, to insure success in
plating upon all metals and metallic alloys, must have two solutions of silver ; the
first to whiten or fix the silver to such metals as iron, steel, Britannia metal, and
German silver ; the second to finish the work, as any amount of silver can be deposited
in a reguline state from the second solution. First, or Whitening Solution. — Dissolve
2^ lbs. (troy) of cyanide of potassium, 8 oz. carbonate of soda, and 5 oz. cyanide of
silver in one gallon of rain or distilled water. This solution should be used with
a compound Iwttery, of three to ten pairs, according to the size of the work to be
plated. Second, or Finiehing Solution, — Dissolve 4 J oz. (troy) of cyanide of potas-
sium, and 1^ oz. of cjranide of silver, in 1 gallon of rain or distilled water. This
solution should be used with one large cell of Smee's battery, observing that the silver
plate is placed as near the surface of the artides to be plated as possible. — N.B. By
using the first, or whitening solution, you may insure the adhesion of silver to all
kinds of brass, bronze, red cock metal, tjpe metal, &c., without the use of mercury,
which is so iigurioos to the human system. To prepare a Solution of Gold. —
Dissolve 4 oz. (troy) of cyanide of potassium, and 1 oz. of cyanide of gold, in 1
gallon of rain or distiUed water. This .solution is to be used warm (about 90^ Fahr.)
with a battery of at least two cells. Gold can be deposited of various shades to suit
the artist, by adding to th3 solution of gold a small quantity of the cyanides of silver,
copper, or zinc, and a few drops of the hydro-sulphuret of ammonia.'' .
ELECTRO-PLATING BATR See Cyanides.
ELECTRO-SORTING APPARATUS. — M. Froment has devised an apparatus
for the separation of iron firom matters by which it may be accompanied. The ap»
?iratns consists of a wheel carrying on its circumference eighteen electro-magnets,
he iron ore reduced and pulverised is spread continually upon one of Uie extremities
of a cloth drawn along with it, and passed under the electro-magnets in motion. The
iron in the ore which has of course been brought into a magnetic state by any of the
processes by which this may be effected, is separated by the magnets, and the
imparities carried onward. See De la Hive's Electricity,
ELECTRO-TELEGRAPHY. The simultaneous appearance of the electric spark
at the respective ends of a long conducting wire forcibly arrested the attention of
electricians in the early days of the science.
A series of remarkable experiments were made by Dr. Watson, commencing on
July 14th, 1747; when he passed an electric discharge fh>m the Thames bank at
Westminster to the opposite bank at Lambeth, by means of a wire suspended to
Westminster Bridge. He continued his researches; and, on August the 5th of the
following year, he arranged 12,276 feet of wire at Shooter's Hill, the beginning, the
middle, and the end of which were led into the same apartment He found out that
the electric signs at the middle of the wire coincided in time with the discharge at the
two ends, proving that the passage, at least in such a length of wire, was instantaneous.
In reference to these results Professor Muschenbrock wrote to Dr. Watson; ^'Mag^
nificenttssimis tuis experimentis, superasti conatns omnium."
The idea of applying this property to the transmission afar of telegraph signals
proper was an early and natural result of these discoveries. But many onward steps
were necessary before the idea could assume any definite ibrm ; and further advances
in knowledge were essential before the idea could be realised.
It would far exceed our limits were we to attempt the most hurried sketch of the
history of this art ; we shall therefore content ourselves with illustrating the leading
doctrines, that have been realised in the telegraph systems which are most in favour
at the time in which we write.
Locked op, as it were, in all bodies, is a large store of electric force,- the equilibrium
of which is disturbed in a greater or less degree by a variety of causes, some extremely
simple, others more complex ; and, according as one or other cause is in operation,
u 3
102 ELECTRO-TELEGRAPHr.
the conditions under which the electric force is manifested vary ; some conditions
being very unfavourable, and others very favourable to the object in view.
Friction is a well known means of producing electric effects. Amber (in Gretk
electron) was the first substance on which they were noticed in a special manner, and
hence the name. Light bodies, such as gold leaf, or feathers, are attracted by rubbed
amber ; the leaf gold is quickly repelled again, the feathers not so readily. In doe
course it was discovered that this difference of behaviour is due to the gold conducting
electricity, and (he feathers not so; the one allowing the force to diffuse itself about it,
the other receiving and retaining it only in or near the points of contact ; if the former
property were universal it would be impossible to collect electricity ; if the latter, it
would be impossible to get rid of it Conduction is well illustrated and turned to
useful account in the iron and copper wires, by which distant telegraph stations are
connected with each other ; inflation, by the glass or porcelain articles with which
the said conducting wires are suspended to the poles above ground, and by the gutta
percha with which tho subterranean or submarine wires are covered.
The rapidity with which electric force traverses conductors depends upon the cir-
cumstances under which the conductors are placed; in one case, as in that of wire
suspended in the air, the electric force has little else to do than to travel onward and be
discharged from the far end of the wire ; in the other case, as in that of buried wire,
it has to disturb the electric equilibrium of the gutta percha as it travels onward, and
thus suffers considerable retardation. The greatest recorded velocity of a signal
through a suspended copper telegraph wire is 1,752,800 miles per second, by M.
Hipp ; the lowest velocity through a buried copper wire, 750 miles per second
by Faraday. Intermediate velocities are recorded, for which the nature of the wire
or the conditions under which it was placed were different Wheatstone found the
velocity of electricity under different conditions fVom the above to be 288,000 miles per
second. His wire was copper, and was wotmd on a fhtme. The electricity that was
employed by Mr. Wheatstone in these experiments was obtained from the friction of
glass against an amalgam of tin. The various Telocities are due partly to the con-
ditions under which the conducting wire is placed, and partly, no doubt, to the
varied properties of electricity from various sources. And the very different methods
of reading off the velocities In this and in other cases may have an influence over the
respective values.
Electricity is obtained from other sources than friction with so much greater faci-
lity, and in forms so much more applicable and manageable for telegraphic purposes,
that frictionid electricity has not been applied in real practice. It must not, however,
be passed over in this place, because one of the earliest telegraphs, perhaps the very
first in which a long length of wire was actually used, was actuated by this form of
electricity. In 1816 Mr. Ronalds established, in the grounds attached to his residence
at Hammersmith, eight miles of wire suspended by silk to dry wood, besides 175
yards of buried wire in glass tubes embedded in pitch and enclosed in troughs of
wood. He obtained his electricity from a common electrical machine, and his signals
from the motion of light bodies, balls of elder pith, produced under circumstances
analogous to those to which we have already referred. At the far end of his tele-
graph wire two pith balls were suspended close together. Electricity applied at the
home end of the wire at once diffused itself throughout the conducting system,
including the pair of light balls. Just as we have seen gold leaf recede after having
approached rubbed amber, and acquired an electric charge ; so the pith halls, each
being charged with electricity, derived from the same source, recede finom each other ;
and this in obedience to the fundamental laws of static electricity, for which we
must refer readers to treatises on the subject Here, then, we have one solitary
signal. The manner in which Mr. Ronalds turned it into language was ingenious^
He pressed time into his service, and by combining time and motion he obtamed a
language. He provided a clock movement at each station ; the clocks were so regu-
lated as to be synchronous in their movements ; each of them carried, in lieu of a
hand, a light disc, having the letters of the alphabet and other signals engraved on it.
The disc was hidden by a screen, in which was one opening. It is obvious that if
the clocks were started together, and had uniform rates, the same letter at the same
time would be visible through the opening in each screen ; and letter by letter would
pass seriatim and simultaneously before the respective openings. If absolute unifor-
mity is difficult for long periods, it is practicable for shorter. The sender of a mes-
sage watched the opening of his screen ; the moment the letter approached that he
desired to telegraph he charged the wire with electricity, and the balls at the far
station moved ; the letter then visible there corresponded with the one at the home
station, and was read off The sender watched till the next letter he required came
round, and so on.
Let us now pass on to some of the leading features of electro-telegraphy, as it has
ELECTRO-TELEGRAPHY. 103
been realiaed of late yean, and to a description of lome of the tel^raph instruments
that are moet in use.
Chendcal action is the most fertile sonree of electricity. If a silyer fork and a
Btpel knife are connected together by a piece of wire, and the fork is thnut iDto a
piece of meat, say a hot mutton chop, the moment an incision is made in the meat
with the knife, electricity will pass along the wire, and continue to do so while the
abore disposition of things remains. Upon the proper test being applied, the elec-
tricity is readily detected. This is the current form of electricity. The amount of
force in circulation in this particular combination is not yery great, and its power of
travelling to a distance is not yery high, but still it is quite capable of producing good,
signals, on a delicate arrangement of the needle instrument (of which more here&er)
with which in England we are so femiliar.
The amount of electricitjr obtained b^ means of chemical action, is increased to
the reqmred extent by a judicious selection of metals, and of the liquid or liquids in
which they are immersed. Zinc is inyariably used as one of the metals ; it is repre-
sented by the iron of the knife in the aboye experiment Copper, siWer, and platinum
or graphite (gas carbon) is selected for the other metaL When the two metals are
immersed in a same liquid, a mixture of sulphuric acid with salt-water, or fresh, is
employed. When two liquids are used, they are separated by a porous partition ;
the sine is usually placed in the sulphuric acid solution, and the other metal in a
solution yarylng with the nature of the arrangements proposed. Zinc is naturally
soluble in the acid solution in question $ and would fiierefore waste away and be
consumed at the expense also of the acid, unless precautions were taken to make it
resist the ordinary action of the solyent When zinc is dissolved in mercury it is not
attacked, under ordinary circumstances, by sulphuric acid solution. Hence the plates
of zinc employed in all good yoltaic combinations, as they are called, into which
this acid, in a free state, enters, are protected by being well amalgamated, that is,
they are dipped in a strong acid mixture and well washed ; and are then dipped into
a mercury bath, and are placed aside to drain. The operation is generally repeated
a second time ; and, in the best arrangements, the further precaution is taken of
standing the zinc plate, while in the acid water, in some loose mercury, placed either
in the bottom of the containing vessel, or in a ^tta percha cell : by the latter arrange-
ment, mercury is economised. In single liquid arrangements, it is desirable to select
a metal that is not attacked by the acid. Copper has been extensively used, and is
yery yalnable ; but it possesses the defect of being slowly attackable. The waste,
however, that it suffers in itself from this cause, is of small moment compared with
certain secondary results, which terminate in the consumption of the acid and the
zinc, and the destruction of the functions of the apparatus. Gold or platinum are
free from these defects, but are too costly. Silver, is to a great extent free fi-om
them, and has been much and successfblly used, especially when platinised, that is,
having its snrfiice covered with finely divided powder of platinum. The corrosion
from gas retorts, cut into plates, and similarly treated, fonns with amalgunated zinc
one of the cheapest and most effective combinations.
A single pair of plates, no matter what their character, is unable to produce a fbrce
that can overcome the resistance of a wire of any^ length, and produce an available
result at a distant station; and hence a series of pairs are employed in the telegraphic
arrangements, s {/ig, 704> represents a common mode of arranging a series of pairs of
plates. It consists of a wooden trough made water-tight, and divided into water-tight
cells. The metals are connected in pairs by copper bands ; each pair is placed astride over
a partition, and all the zincs face one way. When the plates (copper-zinc) are placed
in, and the cells are filled up with pure white sand, and the acid water poured in, we
have the very portable battery that was originally used by Mr. Cooke, and is still
much employed in England. When batteries of a higher dass are employed, the
cells are distinct pots or jars ; and great precautions are taken to prevent any conduct-
ing communication existing between the neighbouring cells, save by means of the
copper band. Jn the trough form there is a leakage and loss of force from cell to
eelL The c or copper is the positive end of such a series, and the z or zinc, the
negative; and both are in a condition to discharge, either each to the other, by means
of a wire led from one to the other, or each to the earth, one by a wire leading to
the earth at the place where the battery stands, and the other by a long wire (say a
telegraph wire), leading to the earth at a distant place. The resistance to be over-
come is, in the former case, less ; and the current of force in circulation is propor-
tionately greater. Under whatever circumstances a wire takes part in promoting the
discharge of an apparatus of this kind, the whole of the said wire is in a condition to indi-
cate the presence of the force that is pervading it ; and as the force may be presented to
the wire in either of two directions, that is to say, the copper or the zinc, namely, the
positive or the negative end of the battery, may be presented to the given end of the
H 4
104 ELECTEO-TELEGRAPHT.
telegraph wire, the relatiTe condition or tbe wire will be modified aecordiDgtj. Not
odIj can tbe direction of tliii current foKe b« iiiTertedat pleanire, but it cao be
;04 maintained for 007
length of time, gmt
range men t>, which are
the kejg, com matalors,
or bBodiei of the i^a-
TioDj telegraph instm-
ment< (of which more
hereafter), and are
often tbe onlr part
presenting any tarn-
Eleiity about them.
ii/$.;04, the source of
electricitj, e, ve bait
already deacribedi the
tkbnormal lUte of the
wire, that i* la isj.
tbe telegnph prmer.
is tbe part a.. The
complex iiart, ctmuit-
ing of ipringa, cj-
linden, and ilnds,
ihown below a, it
nothing more than
the neccsaarj mecha-
nical arrangement for
directing kt pleamrt
the CDirent tnuo the
battery s, in either
direction thmngb tbe
wire, and throogh the
part A. By followbg
the letters in the order here given, tbe conrie of the cnrrent may be trjced from iu
leaving, any tbe positive or copper end of the battery, till its return to the line
or negative end iCf/nwwDAZ'iBE. If« companion Instmment were io any
part M the circuit of the wire w w, it wouM corropond in ite signals with the home
iDsImmeatijiij. 704.
One of the propertiea possessed by a wire, during the C of discbarging a Toltaic
battery, is to deflect a magnetised needle. If the two are parallel in tbe normal stale
of the wire, [he needle is deflected this way or that, when the wire is in tbe aboonnal
state ; and if the needle ia very delicate, and a large enough amoiuit«f electricity is
rircalating through the wire, the needle reaches the maximum deflection of SU"
This is an extreme case, and cannot be approached in practice. Indeed, the deflectioa
of any ordinary needle, under the action of an ordinary telegrapb wire, would not be
appreciable. But, as ecay foot of tbe wire has tbe tame amount of reaction, we liave
merely so to arrange things that many feet,- n long length of the wire, shall be made
to react upon the needle at the same time, and thus the effect is moltipllcd in propor-
tion to the length of wire so concentrated. This is managed by covering a con-
siderable quantity of fine wire with illli or cotton, and winding it on a frame A (^j/-
704), suspending tbe needle within tbe f^ame- Such an instrument is colled, from ita
properties, a mullipUtr. It is seen at a glance that the wire of the multiplier is an
addition over and above the length of the actual telegraph wire required for reaching
the distant station, and thus it practically iitcreases tbe distance (0 be traversed: its
amallness adds to this. Tbe multipliers commonly used add a resistance equal to aix
or seven miles of telegraph wire.
Let us now turn to the face of the instnmient. Here we have a dial and an index,
which is on the same axis as the magnetised needle above described, capable of being
d^ectcd to the right or left, and Umitcd in its motion by ivory pins.- We have a
handle fbr working the mechanical part so couuected that, sb it moves to tbe right, it
directs a current into tbe wire such that the needle moves to tbe right, and dim Turaa.
ELECTRO-TELEGEAPHY. * 105
An ilplimliet u conitnieted from the combinalioD of iheit tiro elemeoUrj notimu,
oae or more of either or both luodi of deflectioa being med for the vtrion* letlsn,
ks Ehown OB the engraved dial. Thia ^dj
is Cooke u>d TnieUKoDe's lingle
needle iiutnunent, ^. 70S.
TlM form ud chnnurter of Ibeir
double needle instrament is sbowD in
yfy. T0«. It it precisely a duplicate of
the former i two haadlei, and their
TespeetiTe apriDgl, itudi, and cjlia-
ders, two moltlplien, and two mag-
netiKd needles, with their eztereal
iDdcxea,Bnd twotetegraphwirei. One
batterj, hoverer, it taffleieuL One
or more of either or both kindj of de-
flection of either or both needles,
according to the code engrared on
the dial, constitDlei the alphabet. Thii
iutnunent ia very eiienaiTel^ em-
ployed I menages are tent by it with
extreme rapidity.
Another property poMened by a
■wire coDTeyiug a nureBt ii that of
converting aoft inxi, for the time, into
» magnet. The attraclive power,
which can ihm be given to, and with-
drawn from, the aoA iron at pleanire
is tnnied to osefiil acconnt, either in
prodneing direct meehanicBl action,
or in litieratiag the detents of a rlock
movement. Here alao the effect of the
706
106 EIXOTEO-TELEGEAPHT,
nAituy wire i* inappreciable, ukI many convolutions aroimd the iron are neeettar^
in order to obtain a QMful result.
The umpUst application of thia principle it shown injt^ TOT. Here are two brais
reels, filled with cotton-
707 CDTered copper wire ia one
length. The7 are hollow,
and a U-Kbaped bar of iron
pastes through them, pre-
senting its ends at the lace
turned toward lu in ihe
drawing. This bar be-
comes magnetic, — forms
wliat is called an elictro-
magntt eietj time and at
long at an electrical cur-
rent eirculatei inthewirej
atid its ends become re-
tpectiTclj north and south
poles. A narrow plat« of
termed, is moonled on
pivots in front of the ends
or poles of the magnet ;
it came* a vertical tten
upon which Ibe hammer is
fixed. Ever^ time the
iron bar is mngnetic the armature is attracted, and the hammerstrike* the bell. The
spring or coutact-malier for inlroducicg the current of clectricitf into Ihe cirmit, i»
shown in f)-ont on the right hand side. This is Mr. Wall^er'g bell for signalUng
railway trains from station to stalian. The langoage consists of one or more blows.
One, two, and three blows sre the signalB for common porpoees, half a doien blows is
the limit. The acknowledgment of a ligcai is its repetition. Bj a limple arrange-
ment of an index, that moves in fellowship with the nammer, the eye, M well as the
ear, may read the bell signals.
Fig. 706 shows another apphcation of the direct action of an electro-magnet in pro-
ducing telegraph signals. It is Morse's printing telegraph, very generally used in
America, and used to no small extent in Europe. The coils of wire are shown at
M, (he armature at h, fixed at one end of (he lever p, which is itself carried on centres
at c. The range of motion here is email in order to produce rapid utterance ; it is
reflated by the screws d and i. The reaction of the spiral spring /restores Ihelevcr
to Its normal position each time the magnetism ceasea. The signals consist of dotsiw
dasbes, varioosly combined, made by the pointed screw I upon the slip of paper p,
running from tiie drum at the right in the direction of the arrows ; a few sach
signals are shown upon the end of the paper slip. We have described Ihe telegraph
proper, which is seen to t>e extremely simple. The only parts at all complex are, as
with the needle Inslnimenti already described, the mechaaical parts, namely the train of
wheels for carrying on the paper band, and the key or contact.maker, not shown in
the figure. The amount of pressure required from the point t in order to produce ■
ELECTRO-TELEGEAPIir. 107
tnsTk, it inch that il cannot conTraientl; be prodooed bj the migneCie attraction,
deriTed trmo a current of elMlriciljr that haa come from a far dialant glation in order
to circulate in th« coilt of wire N. This diScnlly doel not prevail in tlir signal-bell*
J&f. 707, which are, at moat, not retioired to be mora than eight orlen milei apirt.and
ID irUeh alao momentam can be and is accnmnlBted «o ai lo coiupire in producing
the final reinlL Mone hai, therefore, had reconrae to a rdaif, ai he calli it. Tbia,
ia principle, ii pretty mnch the wne thing ai the initrnmeot itwlf ; bnt it bai no
bea.Ty woil to do, no mails to make ) it has merely to aet the part of a eontaet-
maker or kej ; it can hence be nude lerj delieate, so a« to act veil by sach cnrrenll
aa woold not produce any motion in uie instrument itself. The batteries which
fnmiah the electricity for doing the actual printing work in Morse's telegraph, are in
tbe aame italion with the inttrumeat itself The office of the relay is lo receive tb«
signals ttaai afar, and to make the necessary connections with the local battery and
instrument so aa to print off the signals on the paper in the usual way. It is obvious
tbat the motions of the instrument and the relay are sympathetic, and that what a
trained eye can read off (Vom the one a trained ear can read off from the other. The
relays ara constructed with mnch finer wire than Is required for the instmrnent
itself, so that the cnrrent circulating in them, although Tery low in force, is multiplied
by a very high number, and becomes equal to the delicate duty require4 of it.
F'$- 709 is another illDstration of the direct application of the electro-magnet without
adTentitioni aid. It represents a detent of McCallnm's Olobolype for recording
signals. The long lube contains small glnxs balls, which are retained therein by a
detent attached to the armature of an electro-magnet Every time the armature il
attracted mu hall is liberated and runs down into a grooTed dial, where it remuDS tbr
iDspectian. One or more tubes aod detents are used, according lo the nature of the
signal required. As applied lo the signal bell 0^- 707) three tubes are used ; one
charged with black balls, for indicating the number r^ bell strokes made i one with white
balls, for indicating the bell signals sent ; one with spotted balls, for marking ofiT the
time in quarters of faaun or intervals of less length.
The balls, when liberated, all run into the same dial ' "*
and arrange themselves seriatim.
We may here refer to the case of another bell or
ahirum, in which the magnetic alCroction derived from
the current that arrives, is not equal lo the mecha'
nical work of striking a blow and sounding a bell;
but which ia able to raise a detent, that had restrained
a train of wheels ; and bo allow tbe mechanism of the
latter to do the work required. This arrangement
is shown in Cooke and Wbeatstone'saUnim,;^. 710 |
I is the bell ; ■■ n, is the doable headed hammer, which
is io &CI the pendulnm, attached to the pallets J^ which
work in a scape-wheel hidden in the figure, and in
gear in tbe usual way with a colled spring in the
boi i, by the train r„ r„ r^ r. The electro-mag- j
Dctic part here, as in other instmmenta, is simple
eaongh ; a c is a lever moving on a centre above I, )
having at one end an armature a, facing the poles
of the electro-magnet < ; and at (he other end c, a
hook which fiices the wiieel r, and by catching in a
notch on its circtunference, keeps the train at rest
But when a current circulates Ihrongh the coils e,
the armatnre is attracted, the hook is raised, the
train i« liberated, and the pendulum -hammer vibrates and strikes a tncceision of
blowa Bi« a support carrying a small spring, which rcaclson the lever, and restores
108
ELECTRO-TELEGBAPHT.
it to itt noTnul poiitioD when the magnetiim cnaea. Thii alanua u nMd for calling the
attention of tel^japh clerks. It re<iiures • liule attention lo keep np tbe proper
adjostment betifeeii the spring on toe one band, and the magnetic attraction on the
The telegraph originsllj adopted and ttill laigtlj lued b; the French Adminia-
tratioo, ia lomewhat akin to the alanun jnat deacnbed. It ha* a train of wheeli, a
acape-wheei villi foar teeth, and a pur of palleta. There ii, however, no pnida-
Inni ; but the pallet! are connected with the armatare of an electro-magiiet, in sncb a
manner that, for each attraction or repulsion of the aimaniTe, the icape-vheel it
Uberated half a tooth ; for an attraction and a repoluon a whole tooth ; ao that fonr
BQCcessive enrrenta, prodncing of coone four coniecntiTe altrsctioni and repnluoni,
prodoce a whole reTOlution of the ccape-wheeL The axia of the latter pniject*
thrangh the dial of the initmment (jip. Til) and cairiea an arm a or bUig.yiS^wbkh,
followiag the motion of the wheel, a able to ii«snme eight distinct podtiona. The
apparatus li geneially double, as shown in the flgnre ; and the signals are made up irf
the various combinations of the eight positions of each of the two arms. The aim is
half blsck, the other half while. The position of the black portion is read off; the
white portion is merelj a counterpoise. When onlj one half of the dial, or one
index is in use, the combisalions are shown bj producing with the one index sue-
ceasively the positions of the two, whose combination makes the signal, always giving
first the position of the left hand index, then that of the right The handles shown
in fhint are the contact-makers ; and are so constructed that the position of the arm
on the dial comcides with the position given la the handle. Fig. 713 is a front view
119 of the two arms 1 part of the dial is
supposed to be removed, so as lo ei-
pose the four-toothed- wheel already
mentioned, and the pulletii x andii
which, in their movement to and fm,
allow of the semi-tooih advances of
the wheel
In these variouG applications of the
eleclro-mBgnet, the armature haabeen
of soft iron, and the only action of
the eleclro-magDet has been to attract
it. It has bees withdrawn from the magnet after the electricity has ceased lo circalile,
intherby its own gravity, by a counterpoise, or by a reacting spring. We now come to a
telegraph that is well known and much used, Henley's magneto- elect ric telegraph, in
which there is no reacting spring ; and in which the movement or signal is produced
by the joint action of attraction and repulsion i and the return to iu normal state by
the same joint action. Each pole of Henley's electro-magnet has a doable instead
of the single termination, that we have been considering in all preceding cases. A
piece of soft iron, like a crescent, is screwed npon each of the poles ; the homs or
cusps of the respective crescents are being and near to each other ; and a magnetised
•teel needle is balanced between them. This arrangement is somewhat Tike the
ELECTRO-TELEGRAPHT. 109
fbllosiDg { I ). So long as no cairent ia cirrulating in the coilg of the eltctro-
magnet, the crescents are impassive son iron, and no one point of either of them
Ws more tendency than any other point to attract either end of the magiiL-tiied needle
that U belvecD them. Bat while a current is circulatlDg-, one of Iho creicenta is
endowed with north magnetic polaritr. xhlch ii especinllj developed at its hornt,
and ihe other with soath polarity. Suppose the boms of the right hand crescent
are nortb poles, those of the left saalh poles, and Ihe top end of the needle is
north. Four forces will conspire to move the needle to the left. Its lop will be
attracted by the left hand crescent and repelled by Ihc right j its bottom will be
repelled by the left, and attracted by the right. When Ibis current ceases to eir-
colate. the aimple attraction between the nta^etised needle and the soft Iran of the
crescent tends to retain it in a deflected portion. This tendency is increased by
a little residoal magnetism, that is apt to remain in the best iron, notwithstanding
ercry care in Its preparation. In order, therefore, to restore the needle to its normal
position, a short quick carrent in the reverse direction Is given. These instniments
are single or double. Only one kind of deflection of the needle Is svsilsble for
actual signals ; the other motion being merely the return to the nonnsl stale. The
single needle alphabet Is composed of deflections of a short or a long duration ; these
■re produced by holding on the current for an instant or for more than an instant ;
and the varloas combinations r>f short and long correspond to Morse's dot and dash
system. The double needle alphabet consists of combinations of the deflection of
either or both needles.
Fit). 7 ISshows Henley's instrument, and, incompleting the description of it, we have
713
to describe another source of electric current to which no allaslou has been hitherto
made. The electricity here employed Is obtained neither by (Hetion nor by ehemical
action, bnl by means of magnetism and motion. If a piece of metal is moved in the
preaence of a magnet, or a msgnet is moved in presence of a piece of metal, a carrent
ofeleetrleily is generated in the metal. The results are multiplied when the metal is
■ colt of covered wire i so that we have here the eonverse of the electro- magnet ; in
the one case electricity had produced magnetism, In the other magnetism produces
electricity ; hence the name mngnelo-eleetric telegraph. We have here a powerful
set of steel magnets a a, all the north ends pointing in one direction, and bound
together with a, plate of iron, and all the south ends similarly arranged in the other
direction. Facing each end, but not qnite in front when at rest, is an electro-
magnet proper, a b, consisting of the U-shaped iron rod and the coil of covered wire,
as described in fig. 707. Each electro- magnet is monoted upon an axis, c is a short
lever or key ; on depressing this the electro-magnet moves from its normal position
In a region of lesser magnetic force, into a new position in the region of greatest
magnetic force, and thus is the doable condition, enunciated above, complied with ;
the copper wire is moved In the presence of a magnet, and this under the most
ftvoorable coodiiioas; and the U Iron, rising from a feeble to a strong magnet, its
lines of magnetic force move in presence of the copper wire. Just as a current,
eosti'n^fVtMn a longdistance, had to be received in Morse's arrangement (_fig. 7D8) in an
electro-magnet of a long coil of fine wire, so as to be much multiplied in order to
do its work, so here a magneto-electric current, that has to be mi to a long distance,
must be generated in a long coil of very fine wire in order to have electro-motive
force sufficient to overcome the resistance opposed to it. In like manner the electro-
mignets of the instrument d, in which It la received at the far-off station, have the
same mnlliplying eharacterislics. The magneto-electric corrent eilats onl^ duiing
the motion of the electro-magnet in front of the steel magnets, and this motion must
be rather brisk, or the change of place is slow and the currecit feeble ; but the corrent
ceases with the motion. The needle, however, remains deflected from causes to which
we have already rrferred, and if the hand ia raised gently, so that the coils return
110
ELECTRO-TELEGRAPHY.
slowly to their normal position, the needle will remain deflected ; but, if the hand is
so removed that the colls return quickly from the region of greatest to one of leaser
magnetic force, a reverse current of lesser force than the original is generated, which
releases the needle from its deflected position and restores it to its normal place, ready
for making the next signal. In a recent form of this instrument Mr. Henley has
obviated the necessity of moving the electro-magnets, still retaining the same funda-
mental principles. He uses a set of large U-shaped permanent magnets, and places
the electro-magnet in the space between the branches of the permanent magnet, and
so that the four poles of the two magnets, the permanent and the electro, shall be
flush with each other or in the salne plane. A couple of iron armatures are mounted
on a disc in front of the magnets. The disc has a motion on a centre ; the armatures
are curved or crescent-shaped. Their form is so adjusted to the relative positions of
the poles of the respective magnets that, in their normal or ordinary position, one
crescent connects the N. pole of the magnet with one, say the upper pole of the
electro-magnet, and the other crescent connects the S. pole of the permanent magnet
with the lower pole of the electro-magnet On pressing a key the dUsc moves, and the
armatures so change in position that the N. pole of the magnet is connected with the
lowert and the S. pole with the upper poles of the electro-magnet B^ this arrange-
ment the polarity of the electro-magnet is reversed at pleasure, and m its transition
from being a magnet with poles in one direction, to becoming a magnet with poles in
the reverse direction, an electric current is generated in the wire with which it is
wound, and the direction of the current is this way or that according as the transition
is from this direction of polarity to that This form of magneto-electric machine
allows of larger electro-magnetic coils being used, and gives the manipulator com-
paratively very little weight to move in signalling.
We have shown how an electric current generates magnetism, and how magnetism
generates another electric current ; it would follow logically that one electric current
should therefore generate another electric current; for the magnetism produced by a cur-
rent circulating in one^ire, must have all the properties of magnetism, and among them,
that of producing another current in another wire; and so it is. A few convolutions of
a large sized wire are coiled round an iron rod ; and outside the larger wire is a very
great length of finer wire. The current from the battery is called the primary current
in this arrangement ; and the moment it begins to circulate in the large wire, it
magnetises the iron and generates a current, called secondary, in the fine wire, which
is able to penetrate to a very great distance. When the primary current ceases,
magnetisation ceases, the lines of magnetic force disappear, and a reverse secondary
current is produced. This was the method proposed for obtaining the secondary cur-
rent for traversing the Atlantic Ocean from Ireland to Newfoundland. The large
wire is not necessarily first coiled on ; in the coils for the Transatlantic telegraph it
was coiled outside. Nor is the presence of iron essential to obtaining secondary
currents.
It will have been noticed in all the arrangements which have hitherto been
described, that the signals are produced by motions, — that the electric current on
reaching the far station is multiplied by being directed through many convolutions of
wire, and is made to act upon either a piece of soft iron or a piece of magnetised steel,
and to move them, the motion being turned to account directly, or by the intervention
of mechanism. We have yet another property of electricity, that has been very
successfully applied to the production of telegraphic signals by Mr. Bain, in his
electro-chemical telegraph. If a current of electricity is led into a compound fluid
body, say into water by one wire and out of it by another wire, the body is decom-
posed into its constituent elements, one of which, the oxygen in the case in question,
makes its appearance at one wire and the other — the hydrogen makes its appearance
714 at the other wire. The same holds good
with bodies of a more complex character in
solution in water. The compound selected
by Mr. Bain is cyanide of potassium. With
a solution of this, he saturates a long ribbon
of paper, similar, to that employed in Morse's
telegraph. He causes the paper b {Jig,
7 14) to pass over a drum of brass r, between
the metal of r and an iron point or stylus
p. The electric current enters the appa-
ratus by the point p, passes through the so-
lution of cyanide of potassium, with which
the paper b is saturated, and out by the
spring p', which is in metallic contact with the drum b. Decomposition takes place
and the well known cyanide of iron (Prussian blue) is formed at the point of contact
ELECTRO-TELEGRAPHY.
Ill
of the iron stylos p with the paper, the iron of the compoaDd being sopplied by the
stylus Itself. The paper is carried on by ordinary mecluinism ; and a dot and dash
alphabet is formed, according to the duration of coutacts at the sending station. There
is a single wire and a double wire code ; and the signals appear as deep blue marks
upon the paper. Sopplies of paper saturated with the solution are kept in reserve.
This is unquestionably a telegraph of extreme simplicity. It has been employed with
much success.
Mr. Whitehonse prepared for the Atlantic Telegraph a system in which motion
and chemical action each play their part. The secondary currents that he employed
were not able to produce ihe chemical decomposition that he requires for his signals.
He therefore receiyed them in a very sensitiye relay, either an electro-magnet or a
multiplier. The relay was a contact-maker, and connected the necessary number of
local batteries with the printing apparatus, which consists of a ribbon of paper, satu-
rated with a chemical solution and passing between a drum and a steel point
We should exceed our limits, were we to attempt the description of some of the many
other forms that have been proposed. The above are good illustrations of the leading
principles, and are all in successful nse. Some telegraphs will print in ordinary cha-
racters ; this result is only attained by much complexity ; and its yalue is more than
qaestionable,it being as easy to learn a new code as anew alphabet ; and telegraph clerks
read their signals as readily as they read ordinary writing or printing, and they acquire
their knowledge in a yery short time. Hence probably it is that telegraphs to print
in ordinary characters are but little known in real practice ; nevertheless, some very
promising instruments of the class have been produced, by House, and especially one
more recently by Hughes, both of the United States. The following table has been
drawn ont as an illustration of the codes of some of the chief instruments that have
been the subject of this article. It shows the number and nature of the signals (de-
flections, dots, dashes) for producing the name of the great discoverer of electro-
magnetism, which is the foundation of electro-telegraph. The figures on the right are
the number of marks or signs in printing and in each kind of telegraph.
1. Single 1 Cooke
I and
f Wheat- ^
2. Double J stone.
3. Single 1
I Henley
4. Double J
5. Morse
{
6. Single '
7. Double
fiain
O
///
///
\///
E
W
R
V
/ ////////
//W /\\\/
• — •
s
\//
\///
• •
\//
£
D
7
W
V
20
/
V
18
•
16
//
/
19
•
— • •
15
•
• • —
17
— "
•_^ i—
16
The Rheo-dectro-atatie system of telegraphy was first described by M. Botto, in 1848.
It is applicable to some but not to all forms of telegraph. It has been applied on iJie South
Eastern Railway to the signal-bells {Jig, 704), for the purpose of reducing the amount
of battery power required under other circumstances to be maintained. The wire, by
which a pair of bells are connected, is in its normal state in permanent connection
with the similar pole, say the positive, of batteries of equal power at the respective
stations, so that two currents of equal power are opposed to and balanced against each
other. Under these circumstances, the wire is in a null, or rheo-electro-static state ;
neither current circulates. If the connection of one of the batteries is reversed, so
that its negative pole is presented to the wire, then the currents of both batteries are
in the same direction, and they circulate as one current, equal in value to the combined
foree of the two •batteries. The application is obvious ; that, whereas, under the
ordinary system, a whdfe battery, of force sufficient to traverse the distance and do
effective work, must be at each station, under this system only half such battery is
necessary at each station, for producing the same effective work. Also, if a little
more battery power is placed at each station than is necessaryfor the actual work
112 ELECTRO-TELEGRAPHY.
required, ligntle of higher power are obtained under common cireanutances ; itnd
also Ihe eqailibrium of (he tvo opposed currents may be disturbed at any place
between Ihe two statioas. and signals may be made by merely making a conneclioD
belween (he line-wire aod the earth ; because the negalive pole at each station is fitted
np in penmrnent connection with the earth ; and, as the poeilJie poles are in like
conncclioQ with the liue-irire, eacli battery current is made to circulate throagh iti
own signal-belt every time the earth and line-wire are placed in connection. By Ihii
means the guard of a train can make signals of distress to the nearest station without
the aid of portable apparatus. Considerable care is required to obtain good commoni-
catloD with the earth ou the open railway for making distress signals, or otherwise the
discharge is imperfect, and no signal is made. Fish-jointed rails are very valuable for
this purpose ; in their absence, especially at embankments, metal must be bnrit^ for
the purpose at intervals in the moist earth, and a wire attached fbr nte. Coalact
springs ou the telegraph poles are proposed.
Telegraph wires are suspended to polea by in-
'"^ sulators of earthenware, glass, or porcelain; the
material and shape varying according to the ex-
perience of the engineer and the length of lioe
to be insulated. In very short lengths, the battery
power required for overcoming the recistance ii
not great ; it will therefore not overeome tbe reaist-
ance of an insulator of moderate quality, and escape
to the pole and thence to the earth ; but the battery
power required to oiereome the resistance of very
long lengths of wire is equally able to overcome
the resistances presented by inferior iasulatorc, and
to escape in considerable quantities at every pole;
BO that tbe force which reachea tbe Car
TIG station would not be equal to ita vork.
i-^~^ It >< for these long lines that the
S-^rfj greatest ingenuity has been expended
Qt:°^D in constructing iasulators. Fine porce-
\^'(y laio is most in favour from its present-
^^' iag a very smooth surface, snd being
""^^ less bygroaietric than glass i snd it is
distorted into most mysterious looking
shapes in order to present as great a
distance, and one as much sheltered ai
possible, between the part, with vhich
the line-wire is in contact, and the
pail that is in contact with the pole.
For fiublerranean and submarine
wires still greater care is neceseary,
becaoie they are in tbe very bosom (>f
the earth or sea, to which the correut
will escape, wbtn and where it can,
in order to cotnplcte the discharge.
Fig. 715 represents the cable that hat
been lying in the British Channel be-
tween Dover and Calais, since Sep-
tember, 1851. It contains fonr Ko.
16 copper wires, each wire is donbly
covered with gutta-pereha. The four
wirts are then twisted into a rope ;
and the rope is thickly covered, firat
with hemiK'n yarn, tarred, and finally
with a jacket often No. 1 iron vires.
The cable is shown in perspective and
in section, i^'ij. 716 shows the per-
specLive and section of Ihe Irish, a
single wire cable. It consists of a
single ccnttal conductor, of one No,
16 copper wire, dojibly covered with
gutia percba, then with hempen yam
as before ; and finally with a protecting
jacket of ten No. 8 iron wire*. The
Calais cable weighs 7 tons pet mile; iLc Irish, 2 tons per mile. The Atlantic
ELIASITE. 113
telegraph caUe* of which nearly 3000 miles were prepared, is in section, just the siie
of a siWer threepenny piece. It is a single wire cable, the wire was a strand of seven
Mow 22 copper wires, trebly coTered with gutta percha, then with yam, and protected
with eighteen strands of seven wires each, of No. 22 iron wire. It weighs 19 cwt.
to the mile. This cable is lost The iron jacket is in disrepate now for deep sea
cablea Hemp is preferred.
Telegraph signals pass with &r less rapidity through baried and through subma*
rino wires, than along the ancient aerial wires. The slow travellings mentioned
above, were through wires of this kind. We must refer to treatises on Electricity
for fhll details of the conditions presented by a telegraph cable. In practice it is
found that on first sending a signal into a snbmergal wire, the electricity is de-
layed on its road, in order to proiduce a certain electrical condition upon the surface
of the gutta percha that is in immediate contact with the conducting wire. Nor is
thiaaU ; before a second distinctive signal can be sent, it is necessary that the con-
dition produced by the first signal shall be destroyed ; and this is an operation,
requiring even more time than was consumed in the mere act of producing it These
two clnsws of retardation, especially the latter, were lar^ly manifested in the Atlantic
cable; and have called forth all the ingenuity of electricians, in order to mitigate or
to modify them.— a V. W.
ELECTRUM, or ELECTRON. The ancient Electrumwas an alloy of gold with \
part silver. The Electrum of Kalproth is gold 64 silver 36. The ancient name of amber.
The modem Electrum is an alloy of copper, zinc, and tin, with sometimes nickel.
ELEMENTS. See Equtvalbnts, Chemical.
ELEML This appears to be the resinous product of various terebinthinous
trees. The Edinbur^ College, states it to be a ** concrete resinous exudation ft*om
cme or more unascertained plimts." And the London Pharmacopoeia describes it, as a
concrete turpentine derived ftx>m an unknown plant In the former edition Amyria
Elemifera was named as the plant producing this resin. This error was due to Lin-
niens, who confounded under one name two distinct plants. The larger quantities of
Eiemi come to us from the Dutch settlements through Holland. It is imported in ** the
lump,'* and in masses weighing from one to two pounds each enveloped in a pahn leaf.
Bonastre ^ives the oonstituents of Elemi :
Volatile oil 125
Resin soluble in hot and cold alcohol • - - - 60O
Resin soluble in hot but not in cold alcohol - - - 24*0
Bitter extractive - - - - - - -20
Impurities -------- i'5
The resin soluble in cold alcohol consists according to Johnston of C*H"0*, while
the latter {EHmine) is composed of C^H"0.
Elemi is employed in making lacquer. See Vabnish.
ELEUTRIATE. (Soittirer, Fr., Sehlemmen, Germ.) When any insoluble powder
such as chalk is diffused through a large body of water, and then allowed to subside
slowly, of course the larger particles will by their pavity be the first to subside. If
then the supernatant liquor is poured off, or better, if drawn off by a siphon, the finer
powder will be collected in the next vessel ; and by repeating this process an impalpable
powder may be obtained. This process is called Elutriation,
ELEPHANTS' TUSKS. See Ivobt.
ELIASITE. An ore of Uranium, a mineral allied to pitch blende, but differing from
It widely m its large proportion of water and lower specific ^vity (4*086 to 4-237>
It ooenn with fluor, dolomite, quarts, &c., at the Elias mme, Joachimstal, in large
flattened pieces, sometimes half an inch thick, of a dull reddish-brown colour,
approaching to hyacinth-red on the edges.
It is subtranslucent, with a greasy subvitreons lustre, and affords a dull streak,
varying from wax-yellow to orange. Hardness between calcite and fluor spar.
It is composed of Peroxide of Uranium - - • 61*33
,, Alumina ----- 1'17
„ Peroxide of iron - - - - 6*63
fp Protoxide of iron - - . - i*09
„ Lime .----- 3*09
M Magnesia • - • • - 2*20
„ Oxide of lead ... - 4*62
„ SUica 5*13
„ Carbonic acid .... 2*52
0 Phosphoric acid - - • - 0*84
n Water ..... 10-68
99*80
Vo(L.IL 1
114 EMBOSSING.
Before the blowpipe it affords a reaction like pitchblende, I>eooinpQMd hj
muriatic acid. — H. W. B,
£LIXIR OF VITRIOL, a preparation of sulpharic acid, with some aromatics,
ELM. ( Ulmut. Orme, Fr. ; Uime^ Ger.) Of this European timber tree there ire
five species. The Ulmua CampesirU, the English Elm, is regarded in this coontry as
one of the finest of European decidnous trees for park scenery; it lives for upwards of 200
years, forming a remarkably straight tall trunk. The quality o£ timber depends a good
deal on the soil in which it is grown, being always best on a dry, loamy soil, and
plenty of air. The Ubtuts motUanth the Mountain-Scots or Wych Elm : the trunk
is not so lofty nor the wood so heavy as the English Elm ; and though coarse gruned
is ver^ highly prized by shipbuilders and cartwrights. It possesses great longitudiul
adhesion, and is consequently one of oar stiffest and straightest timbers. These
woods are not liable to split, and bear the driving of nails or bolts better than any
other timber, and are exceedingly durable when constantly wet They are therefore
much used for the keels of vessels, and for wet fonndations, waterworks, piles, pumps,
and boards for coffins. On account of its toughness it is sdected for the oaves of wheds.
. and for the gunwales of ships.
ELVANS. Granitic and felspathio prophyritio rocks, which are frequently found
traversing both the granite and slate rocks.
'* The Elvans or veins of quartsiforous porphyry, that is, a granular crystalline
mixture of feldspar and quarts which are common both in Cornwall and Devon, and
near the granite of the south-east of Ireland, are probably in reality granite veins, or
veins proceeding from a granitic mass." — Jukes,
** When these granite-veins are of a large size they are termed Elvan courses ; indeed
this is the only distinction between these two forms of elongated masses of granitic
rock. In composition these eWans are either shorl-rock, eurite, felsparite, or even
varieties of fine-grained granite.** — Boose,
EMAIL OMBRANT, a process whidi consists in flooding coloured but transparent
glazes over designs stamped in the body of earthenware or porcdain. A plane surfocc
18 thus produced, in which the cavities of the stamped design appear as shadows of
various depths, the parts in highest relief coming nearest the surface of the glaxe,aBd
thus having the effect of the lights of the picture. This process was introdnced by
the Baron A. De Tremblay of Rubelles, near Melnn.
EMBALMING. (^EnUKiumement, Fr. ; Emhalaomen^ Germ.) An operation employed
by the ancients to preserve human bodies from putrefaction. From their using haisams
in the process, the name was derived. See Disinfection, Pvtbsf action.
EMBOSSING. One of the plans introduced for embossing cijOTH by machinery
which appears to be the most effective, is that of Mr. Thomas Greig, of Rose Bank,
near Bury. This machine is thus constructed.
Figs, 71 7, 718 represent three distinct printing cylinders of copper, or other suitable
material a, b, c, with their necessary appendages for printing three different cokmrs
upon the fabric as it passes through the machine ; either of these cylinders a, b, or c,
may be employed as an embossing cylinder, without performing the printing proceo,
or may be made to effect both operations at the same time.
The fabric or goods to be operated upon being first wound tightly upon a roller,
that roller is to be mounted upon an axle or pivot, bearing in arms or brackets at the
back of the machine, as shown at d. From this roller the fabric aaaavi conducted
between tension rails, and passed under the bed cylinder or paper bowl £, and from
thence proceeds over a carrier roller f, and over steam boxes not shown in the drawing,
or it may be conducted into a hot room, for the purpose of drying the colours.
The cylinders A, B, and c, having either engraved or raised suifoces, are connected
to feeding rollers 6, 6, 6, revolving in the ink or coloured troughs c,c^c\ or endless
felts, called sieves, may be employed, as in ordinary prioting machines, for supplying
the colour, when the device on the surface of the cylinders is raised ; these cylinders,
may be furnished with doctors or scrapers when required, or the same may be applied
to endless felts.
The blocks have adjustable screws g, g^ for the purpose of bringing the cylinders up
against the paper bowl with any required degree of pressure*, the cylinder b is
supported by its gudgeons running in blocks, which blocks slide in the lower parts
of the side fhtmes, and are connected to perpendicular rods t, having a^jus^le,
screw nuts.
The lower parts of these rods bear upon weighed levers A, k^ extending in front of
the machine ; and by increasing the weights /, /, any degree of upward pressure maybe
given to the cylinder b.
The colour boxes or troughs c, c, c, carrying the feeding rollers 5, 6, 5, are fixed (m
boards which elide in grooves in the side frames, and the rollers are adjusted and
brought into contact with the surface of the printing cylinders by screws.
EUBOSSINO. lis
If k Umck clbtli (liiwld b« nqaired to ba introduced batweeo the cylindrical brd or
paper bowl K,u>d thchbriesao,** theordiaarjIeUor blanket, i( maj, fiH' printing
and embcMaing cotton, lilk, _ .
or paper, ba of linen or
(H>naa ; bat if woollen
gooda an to be operated
npon, a cap of felt, or some
■ueh material, moat be '
bonnd rmind tbe paper
bovl, and the felt «r
blanket mnit be need for
the back cloth, vhicb ia U
be conducted otot tbe
ToUera h and l
For tbe porpoae of em-
boaiing the G^nic, either
of tbe rollen A, b, or c^
majr be employed, obaerr-
lag that Ihe anrhce of tba
roller maat be cat, ao ai to
leave tbe pattern or dcTJoe
elevated Tor emboaaing
TelTeta, plain dotha, and
papers -, bnt for voolleni .
tbe device moH be eica-
Tated, tbM ia, cat in re- 7U
The pattern of tbe em-
boaaing ejlindet -will, bf
the operatii>n, be partially
marked throogb the Gihnc
on to tbe aurhce of the
paper bowl e ; to ohllie-
rale which nuriia fVora
the anrfiue of the bowl, a*
it IcTnlvva, the iron cylin-
der roller o it employed;
bnt aa in the emboasing of
the same putemi on paper,
B cooDter roQer i» reqnired
to prodnee tbe pattern per-
fectly, the iron roller ii in
that cue dispensed with,
the impreadoD givea to the
paoer bowl being req aired
to be retained on ita anrface nntil the operation is 6nished.
In thia case the relative eircamferencea of the embossing Dvlinder, and of tbe paper
bowl, mast be exactly proportiMied to each other; that is. [he circa nifertnee of the
bo* I most be equal, exactly, to a given number of circumferences of the embowing
Cylinder, very accnratelj meamred in order to prewrve a perfect register or cnii>-
odi^ce, aa they continae revolving between the pattern on the surrace of the em<
bossiug cylinder and that indented into the snrbce of the piper bowL
The axle of tbe paper bowl e, turns in brasses fitted inloslots in Ihe side framea. and
It may be railed i^ hand th>m its bearings, when required, by a lever i, extending in
fronL This lever is affixed to theend of a horirontal shaft L.i^ cnwsing (he machine
•een in the figures, at tbe back of which shaft there are two segment levers i>, p, to
which bent rods q, q, are attached, having books at their lower ends, passed under the
aile of the bowl. At the reverse end of the shaft i. a ratchet-wheel r, is affixed, aitd
a pall or click mounted on the side of the frame lakes into the teeth of tbe wheel r,
and thereby holds up the paper bowl when reqnired.
When the iron roller a, is (o be brought into operation, the vertical screws (, t,
monnled in tbe upper parts of the side fhunes. are turned, in order to bring down the
bniaes H, which carry the axle of that roller and slide in slots in the side ftames.
The cyliodera i., n, and c, are represented hollow, and may lie kept at any desired
temperature daring the operation of printing, by introducing steam into them i and
ni>der the colour boxes c, c, c, hollow chambers are also made for the same pnrpost
Tba degree of temperatare required to be given to these must depend opon tbe nature
116 EMBOSSING WOOD.
of tbe colouring material, and of the goods operated upon. For the purpoae of con-
ducting steam to these hollow cylinders and colour boxes, pipes, as shown at o, r, r,
are attached, which lead from a steam boiler. But when either of these cylinders is
employed for embossing alone, or for embossing and printing at the same time, and
particularly for some kinds of goods where a higher temperature may be required, a
red-hot heater is then introduce into the hollow cylinder in place of steam.
If the cylinder B, is employed as the embossing cylinder, and it is not intended to
print the fabric by that cylinder simultaneously with the operation of embossing, the
feeding roller b, must be remoyed, and also the colour box c, belonging to that cylin-
der ; and Uie cylinders A and c are to be employed for printing the iabric, the one
applying the colour before the embossing is effected, the other after it. It is howerer
to be remarked, that if a and c are to print colours on the fabric, and b to emboss it,
in that case it is preferred, where the pattern would allow it a and c are wooden
rollers havmg the pattern upon their surfaces, and not metal, as the embossing cylin-
ders must of necessity be.
It will be perceived that this machine will print one, two, or three colours at the
same time, and that the operation of embossing may be performed simultaneously with
the printing, by either of the cylinders a, b, or c, er the operation may be performed
consecutively by the cylinders, either preceding or succeeding each other.
The situations of the doctors, when required to be used for removing any snper-
fluous colour from the surface of the printing cylinder, are shown at d,d,di those
for removing any lint which may attach itself, at «, e, e. They are kept in their
bearings by weighted levers and screws, and receive a slight lateral movement to and
fro, by means of the vertical rod m, which is connected at top to an eccentric, on the
end of the axle of Uie roller h, and at its lower end to a horizontal rod mounted at
the side of the frame ; to this horizontal rod, arms are attached, which are connected
to the respective doctors ; and thus by the rotation of the eccentric, the doctors are
made to slide laterally.
When the cylinders a, b, or c, are employed for embossing only, those doctors will
not be required. The driving power is communicated to the machine from any first
mover through the agency of the toothed gear, which gives rotatory motion to the
cylinder b, and from thence to the other cylinders a, and c, by toothed gear shown in
fg- nr.
EMBOSSING LEATHER. Beautiful ornaments in basso-relievo for decorating the
exteriors or interiors of buildings, medallions, picture-frames, cabinet work, &c., have
been recently made by the pressure of metallic blocks and dies by M . Claude Sdimth.
The dies are made of type metal, or of the fusible alloy with bismuth, called d'Arcets.
The leather is beaten soft in water, then wrung, pressed, rolled, and fulled as it were,
by working it with the hands till it becomes thicker and quite supple. In this state
it is laid on the mould, and forced into all its cavities by means of a wooden, bone, or
copper tool. In other cases, the embossing is performed by the force of a press. The
leather, when it has become dry, is easily taken off the mould, howeyer deeply it may
be inserted into its crevices by virtue of its elasticity.
EMBOSSING WOOD. iBossa^e, Ft. i Erhabenes, Arheit, Germ.) Raised figures
upon wood, such as are employed m picture-frames, and other articles of ornamental
cabinet work, are usually produced by means of carving, or by casting the pattern in
plaster of Paris, or other composition, and cementing, or otherwise fixing it on the
surface of the wood. The former mode is expensive ; the latter is inapplicable on
many occasions. The invention of Mr. Streaker may be used either by itself or in aid
of carving, and depends on the fact, that if a depression be made by a blunt instrument
on the surface of Uie wood, such depressed part will again rise to its origind level by
subsequent immersion in the water.
The wood to be ornamented having been first worked out to its proposed shape, is in
a state to receive the drawing of the pattern ; this being put on a blunt steel tool, or
burnisher, or die, is to be applied successively to all those parts of the pattern intended
to be in relief, and, at the same time, is to be driven yery cautiously, without breaking
the grain of the wood, till the depth of the depression is equal to the intended pro-
minence of the figures. The ground is then to be reduced by planing or filing to the
level of the depressed part ; after which, the piece of wood being placed in water,
either hot or cold, the part previously depressed will rise to its former height, and will
then form an embossed pattern, which may be finished by the usual operations of
carving. See Carving bt Machinbrt.
Another process which may be regarded either as carving or embossing wood, is
that patented by Messrs. A. S. Braithwaite and Co.
Oak, mahogany, rose- wood, horse-chestnut, or other wood, is steeped in water for
about two hours ; and the cast iron mould containing the device is heated to redness,
or sometimes to a white heat, and applied against the wood, either by a handle, as a
branding iron, by a lever press, or by a screw-preFs, according to cireumstances ; the
EMBROIDEBING MACHINE:. 117
moalds are made by the iron^ftmoder from plaster casta of the original models or
carvings.
Ebd not the wood been saturated with water, it would be ignited, but until the
moisture is evaporated, it is only charred ; it gives off volumes of smoke, but no flame.
After a short time the iron is returned to the Aimace to be re-heated, the blackened
wood is well rubbed with a hard brush to remove the charcoal powder, which being
a bad conductor of heat, saves the wood from material discoloration ; and before the
reapplication of the heated iron, the wood is a^pun soaked in water, but for a shorter
time, as it now absorbs moisture with more facility.
The rotation of burning, brushing, and wetting is repeated ten or twenty times, or
upwards, until in fact the wood fills every cavity in the mould, the process being
materially influenced by the character and condition of the wood itself, and the degrees
to which heat and moisture are applied. The water so far checks the destruction of
the wood, or even its change of any kind, that the burned surfiice, simply cleaned by
brushing, is often employed, as it may be left either of a very pale or deep brown,
according to the tone of colour required, so as to match old carvings of any age ; or
a very Uttle scraping removes the discoloured surface. Perforated carvings are
burned upon thick blocks of wood, and cut off with the circular saw.
EMBROIDERING MACHINE. (Machine a broder, Fr. ; Steckmaschine, Germ.)
This art has been from the earliest times a handicraft employment, cultivated on
account of its elegance by ladies of rank. But M. Heilman, of Mulbouse, invented a
machine of a most ingenious kind, which enables a female to embroider any design
with 80 or 140 needles as accurately and expeditiously as she formerly could do with
one. A brief account of this remarkable invention will therefore be acceptable to
many readers. It was first displayed at the national exposition of the products of
industry in Paris for 1834. 130 needles were occupied in copying the same pattern
with perfect regularity, all set in motion by one person.
Several of these machines are now mounted in France, Germany, and Switzerland,
and, with some modifications, in Manchester, Glasgow* and Paisley.
The price of a machine having 130 needles, and of consequence 260 pincers or
fingers and thumbs to lay hold of them, is 5000 francs, or 200/. sterling; and it is
estimated to do daily the work of 15 expert hand embroiderers, employed upon the
ordinary fhune. It requires merely the labour of one grown-up person, and two
assistant children. The operative must be well taught to use the machine, for he has
many things to attend to : with the one hand he traces out, or rather follows the design
with the point of the pantograph ; with the other he turns a handle to plant and pull
all the needles, which are aeixed by pincers and moved along by carriages, approaching
to and receding firom the web, rolling all the time along an iron railway ; lastly, by
means of two pedals, upon which he presses alternately with the one foot and the
other, he opens the 130 pincers of the first carriage, which ought to give up the needles
after planting them in the stuffy and he shuts with the same pressure the 130 pincers
of the second carriage, which is to receive the needles, to draw them fh>m the other
side, and to bring them back a^ain. The cluldren have nothing else to do than to
change the needles when all their threads are used, and to see that no needle misses
its pincers.
This machine may be described under four heads : 1. the structure of the frame ; 2.
the disposition of the web $ 3. the arrangement of the carriages; and 4. the construction
of the pincers.
1. The ttructtare of the frame, — It is composed of cast-iron, and is very massive.
F'ig. 719 exhibits a front elevation of it The length of the machine depends upon
the number of pincers to be worked. The model at the exposition had 260 pincers,
and was 2 metres and a half (about 100 inches or 8 feet four inches English) long.
The figure here given has been shortened considerably, but the other proportions are
not disturbed. The breadth of the frame ought to hs the same for every machine,
whether it be long or short, for it is the breadth which determines the length of the
thread to be put into the needles, and there is an advantage in giving it the full breadth
of the model machine, fully 100 inches, so that the needles may carry a thread at least
40 inches long.
2. Dispoeition o/thepiece to be embroidered, — We have already stated that the pincers
which hold the needles always present themselves opposite to the same point, and that
io consequence they would continually pass backwards and forwards through the same
hole, if the piece was not displaced with sufficient precision to bring successively op-
posite the tips of the needles every point upon which they are to work a design, such
as a flower.
The piece is strained perpendicularly upon a large rectangular fVame, whose four
sides are visible in Jig, 719; namely, the two vertical sides at r f, and the two hori-
zontal sides, the upper and lower at f' r". We see also in the figure two long wooden
i3
EUBBOIDEBING MACHINE.
rtntioed to reccWe the embroidery, it vonod and kept Tcrlicall j itntched to ■ proper
degree, ft>r eachof theae besmi bears upon iu end aimall ratchet wb eel g.g; the teeth
of ODe of them beiog iDeliDed in the opposite direction to those of the other. Brudei
the ijitna of lover be&mi, there ii another of two upper beami, which ia hoirever bot
imperfectly aeen in the figure, on Bccoont of the interference of other part* in thia riew
of the maehine. One of these sjstema preaenta the web to the inferior needln, and
the other to the npper needlea. As the two beama are not in the aame vertical plane,
the plane of the web wonld be preaented obliquelj to the needlea were it not for a
atraight bar of iron, roand whose edge the cloth paasea, and which reodera it
▼ertical. The piece is kept in lenaion erosawise by small brass templets, to which the
Itrinn 9" >re attached, and by which il ia pulled towards the sides of [he fhimer. It
renivna to show br what iDgenions means this frame may be abilUd in every poasiblc
direction. H. Heilmann has employed for thia pnrpoae the pantograph which dranghta-
men nae for redaclng or enlarging their plana in detenninate proportions.
b V f t/' (Jig. 719) represent o parellelogram, of which the foar angles (, i', /".
EMBROIDERING MACHINK 119
. C are Jointed in in^ a way that th«j may become Tery acute or very oMaie at plea-
sure, while the aides of coarse continne of the same length \ the sides b b' and & 6^' are
prolonged, the one to the point d, and the other to the point c, and these points e and
d are chosen under the condition that in one of the positions of the parallelogram, the
line c d which Joins them passes through the point/} this condition may be fulfilled
in an infinite number of manners, since the position of the parallelogram remaining
the same, we see that if we wished to shift the point d ftirther from the point b\ it
would be sufficient to bring the point c near enough to hf', or v»e« ucrtd ; but when we
hare once fixed upon the distance &' d^ it is CTident that the distance A'' c ii its neces-
sary consequence. Now the principle upon which the eonstruction of the pantograph
restt is this ; it is sufileient that the three points r^/, and e be in a straight line, in
one only of the positions of the parallelogram, in order that they shall remain always
in a straight line in erery position which can possibly be giren to it
We see in the figure that the side b e has a handle ^' with which the workman
puts the machine in action. To obtain more precision and solidity in work, the sides
of the pantograph are joined, so that the middle of their thickness lies exactly in the
▼erticai plane of the piece of goods, snd that the axes of the Joints are truly perpendi-
cular to this plane, in which consequently all the displacements are eflfected. We
arrive at this result by making fiut to the superior great cross bar z/' an elbow piece
df'^ having a suitable projection, and to which is adapted in its turn the piece <f , which
receiyes in a socket the extremity of the side b d; this piece <f is made fast to df' by
a bolt, but it carries an oblong hole, and before screwing up tiie nut, we make the
piece adTanee or recede, till the ihlorum point comes exactly into the plane of the
weh. This condition bdng fulfilled, we have merely to attach the frame to the angle
/*of the parallelogram, which is done by means of the pieoe r".
It is now obvions that if the embroiderer takes the handle b" in his hand and makes
Che pantograph move in any direction whatever, the point /will describe a figure
similar to the figure described by the point c, and six times smaller, but the point/
cannot move without the frame, and whatever is upon it moving al«>. Thus in tiie
movement of the pantograph, every point of the web describes a figure equal to that
described by the point/ and consequently similar to that described by the point e, but
six times smaller ; the embroidered olijeot being produced upon the cloth in the position
of that of the pattern. It is sufficient therefore to give the embroidering operative who
holds the handle n" a design six times greater than that to be executed by the machine,
and to afford him at the same time a sure and easy means of tncmg over with the
point «, all the outlines of the pattern. For this purpose he adapto to e, perpendicularly
to the plane of the parallelogram, a small style terminated by a point e^, and he fixes
the pattern upon a vertical Ublet s, parallel to the plane of the stuff and the parallelo*
gram, and distant from it only by the length of the style e d* \ this tablet is carried by
the iron rod /» which is secured to a cast iron foot b', serving also for other purposes,
as we shall presently see. The frame loaded with its beams and tto doth forms a
pretty heavy mass, and as it must not swerve from its plane, it needs to be lightened,
in Older that the operative may cause the point of the pantograph to pais along the
tablet without straining or uncertainty in its movements. l£ Heilmann has accom-
plished these objecte in the fbllowing way. A cord e attached to the side 6 e of the
pantograph passes over a return pulley, and carries at ito extremity a weight which
may be graduated at pleasure ; this weight equipoises the pantograph, and tends
slightly to raise the frame. The lower side of the frame carries two rods h and h,
each attached by two arms A A, a little bent to the left i both of Uiese are engaged in
the grooves of a pulley. Through this mechanism a pressure can be exeroised upon
the frvne fkrom below upwards which may be regulated at pleasure, and without pre-
renting the frame firom moving in all directions, it hinden it from deviating from the
primitive plane to which the pantograph was adjusted. The length of the rods H
ought to be equal to the amount of die lateral movement of the frame. Two guides
t ^ carried by two legs of cast iron, present vertical slits in which the lower part of the
frame v' is engaged.
3. DigponUon ofUu earriag€$, — The twocarriages, which are similar, are placed the
one to thie right, and the other to the left of the ftwne. The carriage itself is com -
posed merely of a long hollow cylinder of east iron l, carrying at either end a system
of two grooved casUxrs or pulleys l', which roll upon the horixontal rails k ; the pulleys
are noounted upon a fbrked piece f, with two ends to receive the axes of the pulleys,
and the piece r is itsdf bolted to a prcjecting car / cast upon the cylinder.
This assemblage constitutes, properly spitaking, the carriage, resting in a perfectly
stable equilibrium upon the rails k, upon which it may be most easily moved back-
wards and forwards, carrying its train of needles to be paned or drawn through the
eloth.
H. Heifanann has contrived a mechanism by which the operatire^ without budging
X4
120 EMBROIDEBING MACHINE.
from his place, may condact the carriages, and regulate aa he pleaaes the extent of
their coarse, as well as the rapidity of their moyements. By taming the axes m" in
the one direction or the other, the carriage may be made to approach to, or recede
from, the web.
When one of the carriages has advanced to prick the needles into the stof^ the other
is there to receive them ; it lays hold of them with its pincers, polls them through,
performs its coarse by withdrawing to stretch the thread, and close the stitch, then it
goes back with the needles to make its pricks in retom. * During these movements,
the first carriage remains at its post waitmg the return of the second. Thus the two
chariots make in succession an advance and a return, bat they never move together.
To effect these movements M. Heilmann has attached to the piece o' made Ast to
the two uprights a c and a d of the frame, a bent lever nonf tf*, movable round the
point 0 i the bend n' carries a toothed wheel o', and the extremity n" a toothed wheel
o'' ; the foor wheels m, x', o', and o'', have the same number of teeth and the same
diameter ; the two wheels o' and o'^ are fixed in reference to each other, so that it is
sufficient to turn the handle N to make the wheel o" revolve, and consequently the
wheel o' ; when the lever n o is vertical, the wheel </ touches neither the wheel m nor
the wheel m' ; but if it be inclined to the one side or the other, it brin^ the wheel o'
alternately into gear with the wheel x or the wheel yf. As the operative has his two
hands occupied, the one with the pantograph, and the other with the handle of impol*
sioQ, he has merdy his feet for acting upon the lever n o, and as he has many o&er
things to do, M. Heilmann has adapted before him a system of two pedals, by which
he executes with his feet a series of operations no less delicate than those vhich he
executes with his hands.
The pedals p are movable round the axis p, and carry cords p' wound in an opposite
direction upon the pulleys p' ; these pulleys are fixed upon a movable shaft P' sup-
ported upon one side by die prop e', and on the other in a piece k' attached to the two
great uprights of the frame. In depressing the pedal p (now raised in the figureX the
upper part of the shaft p" will turn from the left to the right, and the lever n o will
become inclined so as to carry the wheel & upon the wheel if', but at the same time *
the pedal which is now depressed will be raised, because its cord will be forced to
wind itself upon its pulley, as much as the other cord has unwound itself; and thus
the apparatus will be ready to act in the opposite direction when wanted.
4, DUposition of the pincers. — The shaft t/ carries, at regular intervals of a semi-
diameter,, the appenda^ q q cast upon it, upon which are fixed, by two bolta, the
curved branches q destined to bear the whole mechanism of the pincers. When the
pincers are opened by their appropriate leverage, and the half of the needle, which is
pointed at each end, with the eye in the middle, enters the opening of its plate, it gets
lodged in an angular groove, which is less deep than the needle is thick, so that when
the pincers are closed, the upper jaw presses it into the groove. In this way the needle
is firmly held, although touched in only three points of its circumference.
Suppose now, that all the pincers are mounted and a^iusted at their proper distances
upon their prismatic bar, forming the npper range of the right carriage. For opening
all the pincers there is a long plate of iron, u, capable of turning upon its axis, and
which extends from the one end of the carriage to the other. This axis is carried by a
kind of forks which are bolted to the extremity of the branches q. By turning that
axis the workman can open the pincers at pleasure, and they are again closed by
springs. This movement is performed by his feet acting upon the pedals.
The threads get stretched in proportion as the carriage is run out, but as this tension
has no elastic play, inconveniences might ensue, which are prevented by adapting to
the carriage a mechanism by means of which all the threads are pressed at the same
time by a weight susceptible of graduation. A little beneath the prismatic bar, which
carries the pincers, we see in the figure a shaft t, going from one end of the carriage
to the other, and even a little beyond it ; this shaft is carried by pieces y which are
fixed to the arms q, and in which it can turn. At its left end it carries two small bars
y and u/, and at its right a single bar^, and a counterweight (not visible in this view);
the ends of the two bars ^ are joined by an iron wire, somewhat stoat and perfectly
straight When the carriage approaches the web, and before the iron wire can touch
it, the little bar w presses against a pin u/, which rests upon it, and tends to raise it
more and more. In what has preceded we have kept in view only the npper range
of pincers and needles, but there is an inferior range quite similar, as the figure shows,
at the lower ends of the arms q. In conclusion, it should be stated, that the operative
does not follow slidingly with the pantograph the trace of the design which is upon
•the tablet or the picture, but he must stop the point of the style upon the point of the
pattern into which the needle should enter, then remove it, and put it down again upon
the point by which the needle ought to re-enter in coming from the other side of the
piece, and so on in succession. To facilitate this kind of reading off, the pattern upon
the tablet is composed of right lines terminated by the points for the entrance and
EMERY.
121
return of tbe needle, so that the openttire (uraally a child) has continaaUy ander her
ejes the series of broken luiee which most be followed by the pantograph. If she
happens to qoit this path an instant, without haTing left a mark of the point at which
ahe had airiTed, she is under the necessity of looking at the piece to see what has been
already embroidered, and to find by this comparison the point at which she most
resume her woriL, so as not to leave a blank, or to repeat the same stitch.
JSxpUination of Figure,
A, lower cross ban, which unite the legs of the two ends of the fhune.
a, the six feet of the front end of the fhune.
of J the six feet of the posterior end of the frame,
a", curved pieces which unite the cross bars a" to the uprights.
b", handle of the pantograph.
h, y<t Vj three angles or the pantograph.
£, point of the side b h" on which Uie point is fixed.
d', point of the pantograph.
d", cross bar in form of a gutter, which unites the upper parts of the firame.
d^ fixed point, round which the pantograph turns.
s, tablet upon which the pattern to be embroidered is put
s', support of that tablet.
e, coid attached at one end to the side 6 c of the pantograph passing oyer a guide
pulley, and carrying a weight at the other end.
e', iron rod by which the tablet b is joined to its support b'.
T, p, uprights of the cloth-carrying firame.
f', r', horiaontal sides of the same frame.
G, four roll beams.
o^', the piece of doth.
^\ the strings, which senre to stretch the cloth laterally.
This machine has not been applied for embroidering nets or muslins, as these fabrics
are not sufiiciently close to hold the needles ; it has been hitherto used for embroidering
cloth for Tests and other purposes, and silk for ladies' dresses. We learn, however,
that some very satisfactory experiments have been made by the Messrs. Houldsworth
of Manchester, which promise shortly to lead to the successfhl application of these
machines to the finer description of fiibrics.
EMERY. This mineral was long regarded as an ore of iron ; and was called by
Haiiy /er oxidi qwartziftre. It is, however, a massive granular or compact variety of
corundum, more or less impure. It is very abundant in the island of Naxos, at Cape
Emerl, whence its name. From this place it is imported in large quantities. It occurs
also in the islands of Jersey and Guernsey, at Almaden in Poland, Saxony, Sweden,
Persia, &c. Its colour varies from red brown to dark brown ; its specific gravity is
about 41)00 ; it is so hard as to scratch quartz and many precious stones.
We have recent accounts of emery discoveries in Minnesota, but nearly all that is
used at present in the arts comes from Turkey, near ancient Smyrna. Dr. Lawrence
Smith, tiie American geologist, made a discovery of a deposit of emery while residing
in Smyrna, and he mi^e an examination of the locality in 1847. Dr. Smith having
reported his discoveries to the Turkish government, a commission of inquiry was
instituted, and the business soon assumed a mercantile form. The monopoly of the
emery of Turkey was sold to a mercantile house in Smyrna, and since then the
price has diminished in the market.
The following analyses are quoted by Dana fh>m an elaborate paper by J. Lawrence
Smith, in the American Jovmal of Science.
Hardneu,
Kulah
Sapphire
being 100.
Specific
Gravity.
Alumina.
Oxide of
Iron.
Lime.
Silica.
Water.
57
4-28
63-50
33-25
0-92
1-61
1-90
Samos
56
3-98
7010
22-21
0-62
4-00
210
Nicaria
55
875
7106
20*32
1-40
4-12
2-53
Kuloh
53
4-02
63-00
3012
0-50
2-36
3-36
Gumuch
47
3-82
77-82
8-62
1-80
8 13
311
Naxos
46
8-75
68-53
2410
0-86
310
4-72
Nicatia
46
3-74
7512
13-06
0-72
6-88
310
Gumuch
42
4-31
60-10
33-20
0-48
1-80
5-62
Kulah
40
3-89
61*05
2715
1-30
9-63
2-00
The mining of the emery is of the simplest character. The natural decomposition
of the rock in which it occurs facilitates its extraction. The rock decomposes into an
122 EMERY.
earth, in whicli the emery is fband imbedded. The quantity procnred under tUese cir«
camstances is so great that it is rarely necessary to explore the rock. The earth in the
neighbourhood of the block is ahnost always of a red coluar, and serves as an indication
to those who are in search of the mineral. Sometimes, before beginning to excsTate,
the spots are sonnded by an iron rod with a steel point, and when any reaistanee is
met with, the rod is rubbed in contact with the resisting bodr, and the effect pro-
duced on the point enables a practised eye to decide whether it has been done by
emery or not The blocks which are of a convenient size are transported in their
natural state, but they are frequently broken by large hammers ; when they resist the
action of the hammer, they are subjected to the action of fire for several honra, and on
cooling they most commonly yield to blows. It sometimes happens that large miisci
are abandoned, from the impossibility of breaking them into pieces of a cooTenient
size, as the transportation, either on camels or horses, requires that the pieces shall
not exceed 100 lbs. each in weight.
When reduced to a powder, emery varies in colour from dark grey to black. The
colour of its powder affords no indication of its commercial value. The powder ex-
amined under the microscope shows the distinct existence of two minerals, oomndnm
and oxide of iron. Emery, when moistened, always affords a very strong argillaceoos
odour. Its hardness is its most important property in its application to the arts, and
was ascertained by Mr. Smith in the following manner: — Fragments were broken
from the piece to be examined, and crushed in a diamond mortar with two or three
blows of a hammer, then thrown into a sieve with 400 holes to the inch. The powder
is then weighed, and the hardness tested with a circular piece of glass, aboot four
inches in diameter, and a small agate mortar. The glass is first weighed, and placed
on a piece of glazed paper ; the pulverised emery is then thrown upon it at intervals,
rubbing it against the glass with the bottom of the agate mortar. The emery is
brushed off the glass from time to time with a feather, and when all the emery has
been made to pass once over the glass, it is collected, and passed through the same
operation three or four times. The glass is then weighed, again subjected to the
same operation, the emery by this time being reduced to an impidpable powder. This
series of operations is continued until! the loss sustained by the gUss is exceedingly
smalL The total loss in the glass is then noted, and when all the specimens of emery
are submitted to this operation under the same circumstances, an exact idea of their
relative hardness is obtained. The advantages of using glass and agate are, that the
latter is sufficiently hard to crush the emery, and in a certain space of time to reduce
it to such an impalpable state, that it has no longer any sensible effect on the glass ;
and, on the other hand, the glass is soft enough to lose during this time sufiicient of
its substance to allow of accurate comparative results. By this method, the best
emery was found capable of wearing away about half of its weight of conunon French
window-glass.
In the ordinary process, the lumps of emery ore are broken up in the same manner
as stone is for repairing macadamised roads, and into lumps of similar size. These
lumps then crushed under stampers, such as are used for pounding metallic ores,
driven by water or by steam power. It is supposed that the stampers leave the frag-
ments more angular than they would be if they were ground under runners, a mode
which is sometimes employed. The coarse powder is then sifted through sieves of
wire cloth, which are generally cylindrical, like the bolting cylinders of com -mills;
but the sieves are covered with wire cloth, which vary from ninety to sixteen
wires to the inch. No. 16 sieve gives emery of about the size of mustard-seed ; and
coarser fhigments, extending nearly to the size of pepper-corns, are also occasionally
prepared for the use of engineers. The sieves have sometimes as many as 120 wires
in the inch ; but the very fine sizes of emery are most commonly sifted through lawn
sieves. The finest emery that is obtained tnm. the manufacturers is that which floats
in the atmosphere of the stamping-room, and is deposited on Uie beams and shelves,
from which it is occasionally collected. The manu&cturers rarely or never wash the
emery *, this is^ mostly done by the glass-workers, and such others as require a greater
degree of precision than can be obtained by sifting.
The following table shows the number of wires nstially contained in the sieyes, and
the names of the kinds respectively produced by them : —
Com emery - - - - 1 6
Coarse grinding emery - - 24
Grinding emery - - - 36
Fine grinding emery - - 46
Superfine grinding emery - 53
Wirei. Wittt.
Coarse fiour emery - - 60
Flour emery - - • - 70
Fine flour emery - • - 80
Superfine flour emery - - 90
£M£BY. 123
Washing emery by hand is far too tediom for those who require Tery large quanti-
ties of emery, each as the manufacturers of plate glass and some others, who generally
adopt the following method: — TweWeor more cylinders of sheet copper, of the common
height of about two feet, and yarying from about three, fiTc, eight, to thirty or forty
iDches in diameter, are placed exactly leTel, and oommunicating at their upper edges,
each to the next, "bj small troughs or channels; the largest yesselhas also a waste-pipe
near the top« At the commencement of the process, the cylinders are all filled to the
brim with clean water ; the pulrerised emery is then churned up with abundance of
water in another ? essel, and allowed to run into the smallest or the three-inch cylinder,
through a tube opposite the gutter leading to the second cylinder. The water during
its short passage across the three-inch cylinder, deposits in that Tessel such of the
coarsest emery as will not bear suspension for that limited time ; the particles next
finer are deposited in the five-inch cylinder, during the somewhat longer time the
mixed stream takes in passing the brim of that Tessel ; and so on. Eventually the
water forms a very languid eddy in the largest cylinder, and deposits therein the very
fine particles that have remained in suspension until this period ; and the water,
lastly, escapes by the waste-pipe nearly or entirely free from emery. In this simple
arrangement, time is also the measure of the particles respectively deposited in the
manufiiccure to which the emery is applied. When the vessels are to a certain degree
filled with emery, the process is stopped, the vessels are emptied, the emery is care-
fully dried and laid by, and the process is recommenced.
Holtzapffel informs us that he has been in the habit, for many years, of employing
emery of twelve degrees of fineness, prepared by himself by washing over.
For optical purposes, Mr. Ross mixes four pounds of the flour of emery of com-
merce, with one ounce of powdered gum-arabio, and then throws the powder into two
gsiilons of dear water ; and he collects the deposit at the end of 10" and SCV', and 2'
!& 2(y and 6<y, and that which is not deposited by one hour's subsidence is thrown
away as useless for grinding lenses.
£mery paper is prepared by brushing the paper over with thin glue, and dusting the
emery-powder over it fh>m a sieve. There are about six degrees of coarseness.
Sieves with thirty and ninety meshes per linear inch, are in general the coarsest and
finest sixes employed. When used by artisans, the emery-paper is commonly wrapped
round a file or a slip of wood, and applied just like a file, with or without oil, accord-
ing to circumstances. The emery-paper cuts more smoothly with oil, but leaves the
work duIL
Emery cloth only differs from emery-paper in the use of thin cotton doth instead of
paper, as the material upon which the emery is fixed by means of glue. The emery
cloth, when folded around a file, does not ply so readily to it as emery-paper, and is
apt to unroll. Hence smiths, engineers, and others, prefer emery-paper and emery-
sticks; bat for household and other purposes, where the hand alone is used, the
greater durability of the cloth is advantageous.
Emery-sticks are rods of board about eight or twelve inches long, planed up square ;
or with one side rounded like a half round file. Nails are driven into each end of the
stick as temporary handles ; they are then brushed over one at a time with thin
glue, and dabbed at all parts in a heap of emery powder, and knocked on one end to
shake off the excess. Two coats of glue and emery are generally used. The emery-
sticks are much more economical than emery-paper wrapped on a file, which is liable
to be torn.
Emery-cake consists of emery mixed with a little beeswax, so as to constitute a
solid lump, with which to dress the edges of buff and glass wheels. The ingredients
should be thoroughly incorporated by stirring the mixture whilst fluid, after which it
is frequently poured into water, and thoroughly kneaded with the hands, and rolled
into lumps before it has time to cooL The emery-cake u sometimes applied to the
wheels whilst they are revolving; but the more usual course is, to stop the wheel
and rub in the emery cake by hand. It is afterwards smoothed down by the
thumb.
Emery-paper, or patent razor-strop paper, an article in which fine emery and glass
are mixed with paper pulp, and made into sheets as in making ordinary paper ; the
emery and glass are said to constitute together 60 percent of the weight of the paper,
which resembles drawing-paper, except that it has a delicate fawn colour. The emery-
paper is directed to be pasted or glued upon a piece of wood, and when rubbed with a
hole oil, to be used as a rasor-strop.
In 1842, Mr. Henry Barclay took out a patent for a method of combining
powdered emery into diact and Japs of different kinds, suitable to grinding, cutting,
and polishing glass, enamels, metals, and other hard substances. The process of
manufacture is as follows:^ Coarse emery -powder is mixed with about half its
weight of pulverised Stourbridge loam and a little water or other liquid, to make a
124 EMETINE.
thick paste ; this is pressed into a metallic moald by means of a screw-press, and after
having been thoroughly dried, is baked or burned in a muffle or close receiver at a
temperature considerably above a red heat and below the full white heat. In this
case, the clay or alumina serves as a bond, and unites the particles very completely
into a solid artificial emery- stone, which cuts very greedily, and yet seems hardly to
suffer perceptible wear.
Superfine grinding emery is formed into wheels exactly in the same manner as the
above, but the proportion of loam is then only one-fonrth instead of one-half that of the
emery. Those emery stones, which are of medium fineness, cut less qoickly, but
more smoothly than the above.
Flour-emery, when manufactured into artificial stones, requires no uniting sub-
stance, but the moistened powder is forced into the metal mould and fired ; some
portions of the alumina being sufficient to unite the whole. These fine wheels render
the works submitted to them exceedingly smooth, but they do not produce a high
polish on account of the comparative coarseness of the flour-emery.
The alumina of emery is believed to be aggregated to the same degree of hardness
as in corundum or adamantine spar ; which is one of the hardest minerals known.
Emery is extensively employed for grinding metals, glass, &c. ; for which parpose it
is reduced to powders of different degrees of fineness by grinding and elutriation.
EMERALD (^Emeraude, Fr. ; Smaragd, Germ.), is a precious stone of a beantiful
green colour ; valued next to diamond, and in the same rank as oriental ruby and
sapphire. It occurs in prisms with a regular hexagonal base; sp. grav. 2*7; scratches
quartz with difficulty ; is scratched by topaz ; fhsible at the blowpipe into a frothy
bead ; the precipitate afforded by ammonia, from its solution, is soluble, in a great
measure, in carbonate of ammonia. Its analysis is given very variously by different
chemists. It contains about 14 per cent of glucina, which is its characteristic con-
stituent, along with 68 of silica, 16 of alumina, a very little lime and iron. The beau-
tiful emerald of Peru is found in a clay schist mixed with some calcareous matter. A
stone of 4 grains weight is said to be worth from 4/. to 5/. ; one of 8 grains, lOiL; one
of 15 grains, being fine, is worth 60/; one of 24 grains fetched, at the sale of M. de
Dree's cabinet, 2400 francs, or nearly lOOL
The beryl is analogous in composition to the emerald, and is employed (when of the
common opaque kind, found near Limoges) by chemists for procuring the earth
glucina.
Fine emeralds are found in a vein of dolomite, which traverses the hornblende
slate at Muzo, north of Santa Fe de Bogota. A perfect hexagonal crystal from this
locality, two inches long, is in the cabinet of the Duke of Devonshire ; it measures
across its three diameters 2 J in., 2| in., 1{ in., and weighs 8 oz. 18 dwts: — owing to
flaws, it is but partially fit for jewellery. A more splendid specimen, though some-
what smaller, weighing but 6 oz., is in the possession of Mr. Hope; it cost 500/.
Emeralds of less beauty, but much larger, occur in Siberia. One specimen in the
royal collection measures 14j inches long and 12 broad, and weighs 16) lbs. troy ;
another is 7 inches long and 4 inches broad, and weighs 6 lbs. troy. — Dana.
The emerald is generally believed to derive its colour from the presence of a minute
quantity of oxide of chrome, the beryl from oxide of iron.
This mineral has been recently examined with great care by M. Lewy, from
whose conununication to the Academy of Sciences we abstract the following : —
** M. Lewy visited a mine called Muzo, in New Granada, Mexico, and obtained some
fine specimens of emeralds, and of the rocks in which those precious stones are found,
lie observed that the largest and finest emeralds could be reduced to powder by a
slight squeezing or rubbing between the fingers when first obtained, but that they
acquired hardness after a certain time and repose. It has been commonly stated
that the colouring matter of the emerald is chrome, but M. Lewy attributes it to an
organic colouring matter, analogous to chloropkyle. He states that the emerald ex-
posed to heat loses all colour ; whereas minerals coloured by chrome, do not lose
their green colour by ignition. His analysis of the Mexican mineral b as fol-
lows : —
Silica -•-....• Q7*9
Alumina - - . . . - 17*9
Glucina •.-.-. i2*4
Magnesia - - - . . - 0*9
Soda - - - - • - - 0-7
The green colour of the emerald is darkest in those specimens which funiish to
analysis most organic matter : it is completely destroyed by heat, becoming white
and opaque.
EMETINE. A base constituting the emetic principle in ipecacuanha. — O. G. W,
ENAMELS. 125
EMPTHEUMA, means the ofFenaWe smell produced by fire applied to organic
matters, chiefly vegetable, in close yessels. Thus, empyrenmatic vinegar is obtained
by distilling wood at a red heat, and empyreumatlc oil from many animal substances
in the same way.
ENAMELS (j^maiur, Fr. ; Schmelzghs, Germ.) are varieties of glass, generally
opaque or colovred, always formed by file combination of different metallic oxides,
to which certMn fixed fusible salts are added, such as the borates, fluates, and phos-
phates.
The simplest enamel, and the one which serves as a basis to most of the others, is
obtained by caldning first of all a mixture of lead and tin, in proportions varying
from 15 to 50 parts of tin for 100 of lead. The middle term appears to be the most
suitable for the greater number of enamels ; and this alloy has such an affinity for
oxygen, that it may be calcined with the greatest ease in a fiat cast-iron pot, and at a
temperature not above a cherry red, provided the dose of tin is not too great. The
oxide is drawn off to the sides of the melted metal, according as it is generated, new
pieces of the alloy being thrown in from time to time, till enough of the powder be
obtained. Great care ought to be taken that no metallic particles be left in the oxide,
and that the calcining heat be as low as is barely sufficient ; for a strong fire frits the
powder, and obstructs its subsequent comminution. The powder when cold is ground
in a proper mill, levigated with water, and elutriated. In this state of fineness and
purity, it is called calcine or fiux, and it is mixed with silicious sand and some alka-
line matter or sea-salt The most ordinary proportions are, 4 of sand, 1 of sea-
salt, and 4 of cakme. Chaptal states, that he has obtained a very fine product
from 100 parts of calcine, made by calcining equal parts of lead and tin, 100 parts
of ground flint, and 200 parts of pure sub-carbonate of potash. In either case,
the mixture is put into a crucible, or laid simply on a stratum of sand, quicklime
spontaneously slacked, or wood-ashes, placed under a pottery or porcelain kiln. This
mass undergoes a semivitrification, or even a complete fusion on its surfiice. It is
this kind of frit which serves as a radical to almost every enamel ; and by varying the
proportions of the ingredient, more fusible, more opaque, or whiter enamels are ob-
tained. The first of these qufdities depends on the quantity of sand or flux, and the
other two on that of the tin.
The sea-salt employed as a flux may be replaced either by salt of tartar, by pure
potash, or by soda ; but each of these fluxes gives peculiar qualities to the enameL
Most authors who have written on the preparation of enamels, insist a great deal on
the necessity of selecting carefully the particular sand that should enter into the com-
position of the frit, and they even affirm that the purest is not the most suitable.
Clouet states, in the 34th volume of the Annales de Chimie, that the sand ought to con-
tain at least 1 part of talc for 8 of silicious matter, otherwise the enamel obtained is
never very glaray, and that some wrinkled spots from imperfect fusion are seen on its
sarfiice ; and yet we find it prescribed in some old treatises, to make use of ground flints,
fritted by means of salt of tartar or some other flux. It would thence api>ear that the
presence of talc is of no use'towards the fusibility of the silica, and that its absence
may be supplied by increasing the dose of the flux. In all cases, however, we ought
to beware iS metallic oxides in the sand, particularly those of iron and manganese,
which most frequently occur, and always injure the whiteness of the frit
The ancients carried the art of enamelling to a very high perfection, and we occa-
sionally find beautiful specimens of their work. Then, as at present, each artist made
a mystery of the means that succeeded best with him, and thus a multitude of curious
processes have been buried with their authors.
The Venetians are still in possession of the best enamel processes, and they sup-
ply the French and other nations with the best kinds of enamel, of every coloured
shade.
Enamels are distinguished into transparent and opaque ; in the former all the ele-
ments have experien^ an equal degree of liquefaction, and are thus run into crystal
glass, whilst in the others, some of their elements have resisted the action of heat, so
that their particles prevent the transmission of light This effect is produced par-
ticularly by the oxide of tin.
The frits for enamels that are to be applied to metallic surfaces require greater fhsi-
bili^, and should therefore contain more fiux ; and the sand used for these should be
calcined beforehand with one-fourth its weight of sea-salt ; sometimes, indeed, metallic
flaxes are added, as minium or litharge. For some metallic colours, the oxides of lead
are very injurious, and in this case recourse must be had to other fiuxes. Clouet states
tbat he has derived advantage from the following mixtures, as bases for purples, blues,
and some other delicate colours : —
Three parts of silicious sand, one of chalk, and three of calcined borax ; or, three of
glass (of broken crystal goblets), one of calcined borax, one-fourth of a part of nitre,
126 ENAMELS.
and one part of weU-vashed-diaphoretic antimony. These oompositions affioidftTerx
white enamel, which accordfl perfectly well with blue.
It is obTious that the composition of this primary matter may be greatly Tarted :
but we should never lose sight of the essential quality of a good enamel ; which is,
to acquire, at a moderate heat, sufficient fluidity to take a shining sarbee, withoat
running too thin. It is not complete fhsion wluch is wanted ; but a pasty state, of
such a degree as may give it, after cooling, the aspect of having suffered complele
liquefaction.
Dead'whiU EnameL — This requires greater nicety in the choioe of its materials
than any other enamel, as it must be free from every species of tint, and be perfectly
white ; hence the frit employed in this case should be itself composed of perfectly
pure ingredients. But a fi'it should not be rejected hastily because it may be some-
what discoloured, since this may depend on two causes ; either on some metallic
oxides, or on fuliginous particles proceeding from vegetable or animal sabstanees.
Now the latter impurities may be easily removed by means of a small qnantity of
peroxide of manganese, which has the property of readily parting with a portion of
Its oxygen, and of thus facilitating the combustion, that is to say, the destractimi of
the colouring carbonaceous matter. Manganese indeed possesses a colouring power
itself on glass, but only in its highest state of oxidisement, and when reduced to the
lower state, as is done by combustible matters, it no longer communicates ctdour to the
enamel combinations. Hence the proportion of manganese shoald never be in excess;
for the surplus would cause colour. Sometimes, indeed, it becomes necessary to give
a little manganese-colour, (1. e. a pink tint) in order to obtain a more agreeable shade
of white; as a little asure blue is added to linens, to brighten or counteract the dnlness
of their yellow tint
A white enamel may be conveniently prepared also with a calcine composed of
two parts of tin and one of lead calcined together ; of this combined oxide, <Mie part
is melted with two parts of fine crystal and a very little manganese, all previously
ground together. When the fusion is complete, the vitreous matter is to be poared
into clear water, and the frit is then dried, and melted anew. The pouring into
water and fusion are sometimes repeated four times, in order to secure a very uniform
combination. The crucible must be carefhlly screened from smoke and flame. The
smallest portions of oxide of iron or copper admitted into this enamel will destroy its
value.
Some practitioners recommend the use of washed diaphoretic uttimony (anti-
moniate of potash, f^om metallic antimony, and nitre deflagrated together) for white
enamel; but this product cannot be added to any preparation of lead or other
metallic oxides ; for it would tend rather to tarnish the colour than to clear ft up ;
and it can be used therefore only with ordinary glass, or with saline fluxes. For
three parts of white glass (without lead) one part of washed diaphoretic antimony
is to be taken ; the substances are well ground together, and fused in the conunon
way.
Blue EnameL — This fine colour is almost always obtained from the oxide of cobalt
or some of its combinations, and it produces it with such intensity tiiat only a very
little can be used, lest the shade should pass into black. The cobalt blue b so rich
and lively that it predominates in some measure over every other colour, and masks
many so that they can hardly be perceived ; it is also most easily obtained. To bring
it out, however, in all its beauty, the other colours must be removed as much as pos-
sible, and the cobalt itself should be tolerably pure. This metal is associated in the
best known ores with a considerable number of foreign substances, as iron, arsenic, cop-
per, nickel, and sulphur, and it is difficult to separate them completely; but for enamel
blues, the oxide of cobalt does not require to he perfectly free fh)m all foreign metals;
the iron, nickel, and copper being most pr^udicial, should be carefully eliminated.
This object may be most easily attained by dissolving the ore in nitric acid, evaporating
this solution to a syrupy consistence, to expel the excess of acid, and separate a portion
of arsenic. It is now diluted with water, and solution of carbonate of soda is dropped
slowly into it with brisk agitation, till the precipitate, which is at first of a whitish
gray, begins to turn of a rose-red. Whenever this colour appears, the whole most be
thrown on a filter, and the liquid which passes through must be treated with more of
the carbonate of soda, in order to obtain the arseniate of cobalt, which is nearly pure.
Since arsenic acid and its derivatives are not capable of communicating colour them-
selves, and as they moreover are volatile, they cannot impair the beauty of the blue, and
hence this preparation affords it in great perfection.
Metallic fluxes are not the most suitable for this colour ; because they always com-
municate a tint of greater or less force, which never fails to injure the purity of the
blue. Nitre is a useful addition, as it keeps the oxide at the maximum of oxidation,
in which state it produces the richest colour.
ENAMELS. 127
YMim £iiaaM21— There are many proceeses for making this colour in enamel ; bat
it is aomeirhat difficult to fix, and it is rarely obtained of an uniform and fine tint It
may be produced directly with some preparations of silver, as the phosphate or snlphate ;
bat this method does not always succeed, for too strong a heat or powerful fluxes readily
destroy it, and nitre is particularly prejudicial. This uncertainty of success with the
salts of siWer causes them to be seldom employed ; and oxides of lead and antimony are
therefore preferred, which afford a fine yellow when oombined with some oxides that
are refractory enough to prcTcnt their complete Titriflcation. One part of white oxide
of antimony may be taken with fh>m one to three parts of white lead, one of alum,
and one of sal-ammooiae. Each of these substances is to be puWerised, and then all
are to be exactly mixed, and exposed to a heat adequate to decompose the sal-ammoniac.
This operation is jndged to be finished when the yellow colour is well brought out
There is produced here a combination quite analogous to that known under the name
of Naples ydlow.
CMmt siisdcs of yellow may be procured either with the oxide of lead alone, or by
adding to it a little red oxide of iron; the tints varying with the proportion of the
Ciouet says, in his Memoir on Enamels, that a fine yellow is obtained with pure
oxide of silTer, snd that it is merely necessary to spread a thin coat of it on the spot
to be eoloored. The piece is then exposed to a moderate heat, and withdrawn as soon
as this has reached the proper point The thin film of metallic silver revived on the
surface bcinff removed, the place under it will be found tinged of a fino yellow, of
hardly an^ ukickness. As the pellicle of silver has to be removed which covers the
cfdonr, it is requisite to avoid fixing this film with floxes : and it ought therefore to
be applied after the fusion of the rest The yellows require in genmd but little
sdkaline flux, as they answer better with one of a metallic nature.
€^rt€n JSntmeL — It is known that a green colour may be produced by a mixture of
yellow and blue; but recourse is sddom had to this practice for enamels, as they can
be obtained almost always directly with the oxide of copper; or, still better, with the
oxide of chrome, which has the advantage of resisting a strong heat
Chemists describe two oxides of copper, the protoxide of an orange colour, which
oommnnieates its colour to enamels, but it is difficult to fix ; the deutoxide is blue in
the state of hydrate, but blackish •brown when dry, and it colours green all the yitreous
comlnnations into which it enters. This oxide requires, at most one or two proportions
of flux, either saline or metallic, to enter into complete fusion ; but a much onaller
dose is commonly taken, and a little oxide of iron is introduced. To 4 pounds of frit
for instance 2 ounces of oxide of copper and 48 grains of red oxide of iron are used ;
and the ordinary measures are pursued for making very homogeneous enamel.
The green produced by oxide of chrome is much more solid ; it is not affected by a
powerful fire, but it is not always of a fine shade It generally inclines too much to
the dead'ieaf yellow, which depends on the degree of oxygenation of the chrome.
Red Eiutmd, — We have just stated, that protoxide of copper afforded a fine colour
when it could be fixed, a result difficult to obtain on accoant of the fugitive nature of
this oxide ; slight variations of temperature enabling it to absorb more oxygen. The
proper point of fusion must be seized for taking it from the fire whenever the desired
odour is brought out. Indeed, when a high temperature has produced peroxidisement,
this may be corrected by adding some combostible matter, as charcoal, tallow, tartar,
&c The copper then retnms to its minimum of oxidisement and the red colour which
had vanished, reappears. It is possible, in this way, and by pushing tiie heat a little,
to accomplish the complete reduction of a part of the oxide ; and the particles of metallic
copper thereby disseminated in a reddish ground, give this enamel the aspect of the
stone called avenHaine, The snrest and easiest method of procnring protoxide of
copper is to boil a solution of equal parts of sugar, and sulphate or noher acetate of
copper, in four parts of water. The sugar takes possession of a portion of the oxygen
of the cupreous oxide, and reduces it to protoxide ; when it may be precipitated in
the form of a granular powder of a brilliant red. After about two hours moderate
ebullition, the liquid is set aside to settle, decanted off the precipitate, which is washed
and dried.
The protoxide properly employed by itself, fbmishes a red which vies with the
finest carmine, and by its means every tint may be obtained fVom red to orange, by
adding a greater or smaller quantity of peroxide of iron.
The preparations of gold, and particularly the oxide and purple of Cassius, are like-
wise employed with advantage to colour enamel red, and this composition resists a
powerful fire tolerably weUL For some time back, solutions of gold, silyer, and platinum
have been used with success instead of their oxides ; and in Uiis way, a more intimate
mixturo may be procured, and, consequently, more homogeneoos tints.
Black EnameL — Black enamels are made with peroxide of manganese or protoxide
128 ENAMELS.
of iron ; to which more depth of colour is ^yen with a little cobalt CUy alone,
melted with about a third of its weight of protoxide of iron, gives, according to Cloiiet,
a fine black enamel.
Violet Enamel — The peroxide of manganese in small quantity by itself fiimishes,
with saline or alkaline fluxes, an enamel of a Tery fine violet hne ; and variatiottt of
shade are easily had, by modify'ing the proportions of the elements of the coloored
frit. The great point is to mamtain the manganese in a state of peroxidation, and,
consequently, to beware of placing the enamel in contact with any substance attractive
of oxygen.
Such are the principal coloured enamels hitherto obtained by means of metallic
oxides ; but since the number of these oxides is increasing every day, it is to be wished
the new trials be made with such as have not yet been employed. From such researches
some interesting results would unquestionably be derived.
Of painting on EneaneL — Enamelling is only done on gold and copper ; for silver
swells up, and causes blisters and holes in the coat of enameL All enamel psdntings
are, in &ct, done on either copper or gold.
If on gold, the goldsmith prepares the plate that is to be painted upon. The gold
should be 22 carats fine: if purer, it would not be sufficiently stiff; if coarser, it would
be subject to melt ; and its alloy should be half white and half red, that is, half silver
and half copper ; whereby the enamel with which it is covered will be less disposed
to turn green, than if the alloy were entirely copper.
The workman must reserve for the edge of the plate a small fillet, which he calls the
border. This ledge serves to retain the enamel, and hinders it from falling off when
applied and pressed on with a spatula. When the plate is not to be counter-enamelled,
it should be charged with less enamel, as, when exposed to heat, the enamel draws up
the gold to itself, and makes the piece convex. When the enamel is not to cover the
whole plate, it becomes necessary to prepare a lodgment for it With this view, all
the outlines of the figure are traced on the plate with a black-lead pencil, after which
recourse is had to the graver.
The whole space enclosed by the ontlines must be hollowed ont in bas-reliefs of a
depth equal to the height of the fillet had the plate been entirely enamelled. This
sinking of the sur&ce must be done with a fiat graver as equally as possible ; for if
there he an eminence, the enamel would be weaker at that point and the green would
appear. Some artists hatch the bottom of the hollow with close lines, which cross each
other in all directions ; and others make lines or scratches with the edges of a file broken
off square. The hatchings or scratches lay hold of the enamel which might otherwise
separate from the plate. After this operation, the plate is cleansed by boiling it in
an alkaline lye, and it is washed first with a little weak vinegar, and then wi£ dear
water.
The plate thus prepared is to be covered with a coat of white enamel, which is done
by bruising a piece of enamel in an agate or porcelain mortar to a coarse powder like
eand, washing it well with water, and applying it in the hollow part in its moist state.
The plate may meanwhile be held in an ordinary forceps. The enamel powder is
spread with a spatula. For condensing the enamel powder, the edges of the plate are
struck upon with a spatula.
Whenever the piece is dry, it is placed on a slip of sheet iron perforated with
several small holes, see Jig, 720, which is laid on hot cinders ; and it is left there
until it ceases to steam. It must be kept hot till it goes to the fire ; for were it
allowed to cool it would become necessary to heat it again very gradually at the
mouth of the furnace of fusion, to prevent the enamel from decrepitating and
flying off.
Before describing the manner of exposing the piece to the fire, we must explain
the construction of the furnace. It is square, and is shown in front elevation in fig, 72 1.
It consists of two pieces, the lower part a, or the body of the ftimace, and the upper
part B, or the capital, which is laid on the lower part as is shown in^. 722, where
these two parts are separately represented. The furnace is made of good fire-clay,
moderately baked, and resembles very closely the assay or cnpellation furnace. Its
inside dimensions are 9 inches in width, 13 inches in height in the body, and 9 in
the capital Its general thickness is 2 inches.
The capital has an aperture or door, c, fig, 721, which is closed by a fire-brick
stopper m, when the fire is to be made active. By this door fuel is supplied.
The body of the furnace has likewise a door d, which reaches down to the pro-
jecting shelf B, called the bib (mentonniire)^ whose prominence is seen at ^fig, 721.
This shelf is supported and secured by the two brackets, F, f ; the whole being
earthenware. The height of the door d, is abridged by a peculiar fire brick o, which
not only covers the whole projection of the shelf E, but enters within the opening of
the door d, filling its breadth, and advancing into the same plane with the inner sur&oe
ENAMELS.
129
of the foHMce. This plate is called the hearth ; its purpose will appear presently ; it
may be taken oat and replaced i^t pleasure, by laying hold of the handle in its front.
Belov the shelf b, a square hole, h, is seen, which senres for admitting air, and for
extractiog the asbet. Similar holes are left upon each side of the surface, as is shown
in the ground plan of the baK,yi^. 722, at h.
On a level with the shelf, in the interior of the furnace, a thin fire-tile t rests, per*
forated with numerous small holes. This is the grate represented in a ground view
in>!^. 72a Figt. 723, 724, 725, represent, under different aspects, the muffle. Fig, 722
shows the eleyation cX its further end ; fig, 724 its sides ; and^. 725 its front part
At i^f4» 722, the muffle is seen in its place in the furnace, resting on two bars of
iron, or, stfll better, on ledges of fire-clay, supported on brackets attached to the
lateral sides of the furnace. The muffle is made of earthenware, and as thin as
possible. The fuel consists of dr^ beech- wood, or oaken branches, about an inch in
diameter, cut to the length of nme inches, in order to be laid in horizontal strata
within the furnace, one row only being placed above the muffle. When the muffle
has attuned to a white red heat, the sheet iron tray, bearing its enamel plate,
is to be introduced with a pair of pincers into the front of the muffle, and gradually
adTaneed towards its further end. The mouth of the muffle is to be then closed with
two pieces of charcoal only, between which the artist nSay see the progress of the
operation. WhencTcr the enamel begins to flow, the tray must be turned round on its
base to insure equality of temperature ; and as soon as die whole surface is melted, the
tray must be withdrawn with its plate, but slowly, lest the yitreous matter be cracked
by sudden refrigeration.
The enamel plate, when cold, is to be washed in very dilute nitric acid, and after-
wards in cold water, and a second coat of granular enamel paste is to be applied, with
the requisite precautions. This being passed through the fire, is to be treated in the
same way a third time, when the process will be found complete. Should any chinks
happen to the enamel coat, they must be widened with a graver, and the space being
filled with ground enamel, is to be repaired in the muffle. The plate, covered with a
pure white enamel, requires always to be polished and smoothed with sandstone and
water, particularly if the article have a plane surface ; and it is then finally glazed at
the fire;
The painting operation now follows. The artist prepares his enamel colours by
pounding them in an agate mortar, with a pestle of agate, and grinding them on an
agate slab, with oil of larender, rendered vificid by eJLposure to the sun in a shallow
vessel, loosely covered with gauze or glass. The grinding of two drachms of enamel
pigment into an impalpable powder will Occupy a labourer a whole day. The
painter should have alongside of him a stove in which a moderate fire is kept up, for
drying his work whenever the figures arC finished. It is then passed through the
moffie.
The following was the process adopted by Henry Bone, R. A., and his son, the late
Henry Pierce Bone, Who have produced the largest enamels ever painted ; and
beyond the time and consequent expense there appears no practical limit to the size
of enamel paintings.
Preparing the jSate, — For small plates (up to two inches long) ptare gold is the best
material. Silver (quite pure) is also useo, but is apt to get a disagreeable yellow
edonr at the edges by repeated firings. For larger sizes, copper is used. The copper
Vol- IL K
ISO
ENAMELS.
726
shoald be annealed antil quite free ftom spring, and then cleaned irith dilute ■olphinie
acid (one part acid, fonr water , and shaped in a wooden moald, afterwards used in
making the plate so as to produce a conirex surface varying according to the siae of
the plate, taking care that the shaping does not reproduce the spring in the copper,
in which case the process must be repeated. If the plate is not raised in the centre,
in the course of repeated firings the comers will rise irregularly, producing nndnUuions
over the plate, perfect flatness being next to impossible for large pictures. The
copper is then laid face downwards on the convex wooden mould used for shaping,
and enamel ground fine with water is spread over it with a small bone spoon ; when
covered, a fine cloth doubled is pressed gently on it to absorb the water, and then it is
fimoothed with a steel spatula. This forms the back of the plate, and when fired this
part is finished. The copper is now reversed on a convex board the exact counter-
part of the other, and covered with white enamel ground fine in the same way as
above. The plate is now ready for firing, and after it has been fired and cooled the
surface must be ground smooth with a flat piece of flint or other hard substance, with
silver sand and water. It must next be corcred with a softer and more transparent
kind of enamel called flux, ground and spread on in the same way as the first enameU
but this time only on the face of the plate. This is fired as before, and when cool the
surface must be again ground smooth, and when glazed in the furnace the plate is
finished. For the first coat a white solid enamel is used to prevent the green colonr
from the oxidised copper showing through ; the second coat is a softer enamel, to
enable the colours used to melt with less heat
Firing. — The plate is placed on a planche of firestone, or well baked Stourbridge
clay, supported on a bed of whiting, thoroughly dried in the furnace, the exact shape
of the plate as originally made, which must be used in all subsequent firings. After
the whiting is formed in the shape of the plate it should be notched with a flat knife
diagonally across, as in the accompanying diagram.
The use of this is to produce an effect of diagonal
bracing while the plate cools, and experience has
shown that it tends considerably to keep the plate in
its original shape. When the plate is small (up to
three inches in length) it may be annealed for passing
into the hot muffle as follows : — The planche bearing
the plate may be placed on another planche heated in
the muffle and placed in the front of the muffle for a few
minutes, until the steam of the plate or the oil of the
picture shall have evaporated ; it may then be put in
the mouth of the muffle and gradually inserted to
the hottest part After firing it should l>e placed on
another hot planche and allowed to cool gradually. Largo pictures require a differf nt
arrangement of the fiirnace. Over the muffle there should be a fixed iron annealhig
box, with an iron shelf and door. The bottom should be of cast iron about one inch
thick. This should be so arranged that when the muffle attains a white heat the
bottom of the annealing box should be of a brightish red at the back, and a dull
blood red in front Large pictures should be placed on the bottom of the box before
the furnace is lit, and the larger the size of the picture the slower should the furnace
be brought to its full heat, so as to allow five or six hours for the largest siae, and two or
three for smaller plates. When fired the picture should be returned to the shelf of the
annealing box, and left there till quite cold, for which purpose large plates require at
least twelve hours. The colours used are mostly the same as those prepared for
jewellers and glass painters.
Enamelling at the Lamp. — The art of the lamp enameller is one of the moat agree-
able and amusing that we know. There is hardly a subject in enamel which may
not be executed by the lamp-flame in very little time, and more or less perfectly,
according to the dexterity of the artist, and his acquaintance with the principles
of modelling.
In working at the lamp, tubes and rods of glass and enamel must be provided, of
all sizes and colours.
The enamelling table is represented in fig. 727, round which several workmen,
with their lamps, may be phwed, while the large double bellows d below is set a-blowmg
by a treadle moved with the foot The flame of the lamp, when thus unpelled by a
powerful jet of air, acquires surprising intensity. The bent nozzles or tubes a, a, jl,
A, are made of glass, and aredrawn to points modified to the purpose of the enameller.
Fig, 728 shows, in perspective, the lamp a of the enameller standing in ics cistern
B ; the blowpipe c is seen projecting its flame obliquely upwards. The blowpipe is
acijustable in an elastic cork d, which fills up exactly the hole of the table into
which it enters. When only one person is to work at a table provided with several
a Planche.
b Bed of whiting.
ENAMELS.
181
lamps, he sits down at the same side with the pedal of the bellows ; he takes oat the
other blowpipes, and plugs the holes in the table with solid corks.
The lamp is made of copper or tin plate, the wick of cotton threads, and either
tallow or oil may be used. Between the lamp and the workman a small board or
727
728
sheet of white iron b, called the screen, is interposed to protect his eyes from the
glare of light. The screen is ^tened to the table by a wooden stem, and it throws
ita shadow on his face.
The enamelling workshop ought to admit little or no daylight, otherwise the artist,
not perceiving his flame distinctly, would be apt tocommit mistakes.
It is impossible to describe all the manipalations of this ingenious art, over which
taste and dexterity so entirely preside. Bat we may give an example. Suppose the
enameller wishes to make a swan. He takes a tube of white enamel, seals one of its
ends hermetically at his lamp, and while the matter is sufficiently hot, he blows on
it a minikin flask, resembling the body of the bird ; he draws out, and gracefully
bends the neck; he shapes the head, the beak, and the tail; then, with slender
enamel rods of a proper colour, he makes the eyes ; he next opens up the beak with
pointed scissors ; he forms the wings and the legs ; finally attaching the toes, the
bird stands complete.
The enameller also makes artificial eyes for human beings, imitating so perfectly
the colours of the sound eye of any indiyidual as to render it difiicult to discover
that he has a blind and a seeing one.
It is dtfiB.caIt to make large articles at the blowpipe ; those which surpass 5 or 6
inches become nearly unmanageable by the most expert workmen.
EMAMELLnfo or Cast Iron and other Hollow Ware for Saucepans, &c. In
December, 1799, a patent was obtained for this process by Dr. Samuel Sandy Hickling.
His specification is subdiyided mto two parts -. —
1. The coating or lining of iron yessels, &c., by fusion with a yitrifiable mixture,
composed of 6 parts of calcined flints, 2 parts of composition or Cornish stone, 9 parts of
litharge, 6 parts of borax, 1 part of argillaceous earth, 1 part of nitre, 6 parts of calx of
tin, and 1 part of purified potash. Or, 2ndly,
8 parts of calcined flints, 8 red lead, 6 borax, 5 calx of tin, and 1 of nitre. Or, Srdly,
12 of potter's composition, 8 borax, 10 white lead, 2 nitre, 1 white marble calcined,
1 argillaeeoos earth, 2 purified potash, and 5 of calx of tin. Or, 4thly,
4 parts calcined flint, 1 potter's composition, 2 nitre, 8 borax, 1 white marble cal«
cined, ^ argifiaeeous earth, and 2 calx of tin.
Whieheyerof the above compositions is taken, must be finely powdered, mixed, fused,
the yitreons mass is to be ground when cold, sifted, and levigated with water. It is then
made into a pap with water or g^m water. This pap is smeared or brushed over the
interior of the vessel, dried and fused with a proper heat in a muffle.
Calcined bones are also proposed as an ingredient of the flux.
The fusibility of the vitreous compounds is to vary according to the heat to be
applied to the vessel, by using various proportions of the silicious and fluxing
materials. Colours may be given, and also gilding.
The second part or process in his specification describes certain alloys of iron and
nickel, which he casts into vessels, and lines or coats them with copper precipitated
&om its saline solutions. It also describes a mode of giving the precipitated copper an
enamel sor&ce by acting upon it with bone ashes and zinc with the aid of heat.
A &etory of such enamelled hollow wares was carried on for some time, but it was
given np for want of due encouragement
A patent was granted to Thomas and Charles Clarke on the 25th of May, 1839, for
a method of enamelling or coating the internal surfaces of iron pots and saucepans, in
K 2
132 ENAMELS.
sach a way as shall preyent the enamel from cracking or gplltting oif from the etkcts
of fire. This specification prescribes the vessel to be first cleaned by exposing it to the
action of dilute sulphuric acid (sensibly sour to the taste) for three or four hoorii
then boiling thcTessel in pure water for a short time, and next applying the eompontinii.
This consists of 100 lbs. of calcined ground flints; 50 lbs. of borax, calcined, and finely
ground with the above. That mixture is to be fused and gradually cooled.
40 lbs. weight of the above product is to be taken with 5 lbs. weight of potter's day;
to be ground together in water until the mixture forms a pasty consistent mass,
which will leave or form a coat on the inner surface of the vessel about one-sixth of an
inch thick. When this coat is set, by placing the vessel in a wann room, tlie second
composition is to be applied. This consists of 125 lbs. of white glass (without lead),
25 lbs. of borax, 20 lbs. of soda (crystals), all pulverised together and vitrified by
fusion, then groand, cooled in water, and dried. To 45 lbs. of that mixture, 1 lb. of
soda is to be added, the whole mixed together in hot water, and when dry pounded ;
then sifted finely and evenly over the internal surface of the vessel previously covered
with the first coating or composition whilst this is still moist This is the glaaing.
The vessel thus prepared is to be put into a stove, and dried at the temperature of
212^ Fahr. It is then heated in a kiln or muffle like that used for glazing china. The
kiln being broaght to its full heat, the vessel is placed first at its mouth to heat it grt-
dually, and then put into the interior for fusion of the glaze. In practice it has been
found advantageous also to dust the glas^ powder over the fused glaze, and apply a
second fluxing heat in the oven. The enamel, by this double application, bcooiDcs
much smoother and sounder.
Messrs. Kenrick, of West Bromwich, having produced in their fiictory and sent into
the market some excellent specimens of enamelled saucepans of cast iron, were sued
by Messrs. Clarke for the invasion of their patent rights ; but after a long litigation
in Chancery the patentees were nonsuited in the Court of Exchequer. The previoiis
process of cleansing with dilute sulphuric acid appeared by the evidence on the trial to
have been ^ven up by the patentees, and it was also shown by their own principal
scientific witness that a good enamelled iron saucepan could be made by Hickling't
specification. In fact, the formulsB by which a good enamel may be compounded are
almost innumerable ; so that a patent for such a purpose seems to be untenable, or at
least most easily evaded. Dr. Ure exposed the finely enamelled saucepans of Messrs.
Kenrick to very severe trials, having fused even chloride of calcium in them, aiMl
found them to stand the fire very perfectly without chipping or cracking. Such a
manufacture is one of the greatest improvements recently introduced into domestic
economy ; such vessels being remarkably clean, salubrious, and adapted to the most
delicate culinary operations of boiling, stewing, making of jellies, preserves, &c.
They are also admirably fitted for preparing pharmaceutical decoctions, and ordinary
extracts.
The enamel of these saucepans is quite free fVom lead, in consequence of the glass
which enters into its composition being quite f^ee fVom that metal In several of the
saucepans wiiich were at first sent into the market, the enamel was found on analysis
to contain a notable proportion of oxide of lead. In consequence of the quantity of
borax and soda in the glaze, this oxide was so readily acted upon by acids that sugar
of lead was formed by digesting vinegar in them with a gentle heat
Enamelled iron saucepans had been many years ago imported from Geimany,
and sold in London. Dr. Ure had occasion to analyse their enamel, and found that
it contained abundance of litharge or oxide of lead. The Prussian government has
issued an edict prohibiting the use of lead in the enamelling of saucepans, which are so
extensively manufactured in Peiz, Gleiwitz, &c. Probably the German ware sent to
England was fabricated for exportation, with an enamel made to flux easily by a dose
of litharge.
A suitable oven or mnfile for lining or coating metals with enamel may have the
following dimensions : —
The outside, 8 feet square, with M^inch walls; the interior muffle, 4 fieet square at
bottom, rising 6 inches at the sides, and then arched over ; the crown may be 18 inches
high from the floor ; the muffle should be built of fire-brick, 2^ inches thick. Another
arch is turned over the first one, which second arch is 7 inches wider at the bottom,
and 4 inches higher at the top. A 9-inch wall under the bottom of the muffle
at its centre divides the fire-place into two, of 16 inches width each, and 3 feet
3 inches long. The flame of the fire plays between the two arches and up through
a 3-inch flue in front, and issues f^om the top of the arch through three holt's,
about 4 inches square. These open into a* flue, 10x9 inches, which runs into the
chimney.
The materials for the enamel body (ground flint potter s clay, and borax) arc first
mixed together, and then put into a rcverberatory furnace, 6 feet 7 inches long, by
ENGRAVING. 133
3 feci 4 inches wide, and 12 inches high. The flame from an 18-inch fire-place passes
over the bearth. The materials are spread over the floor of the oven, about 6 inches
thick, and ignited or fritted for 4 or 5 honrs, nntil they begin to heaTC and work like
yeast, when another coating is pat on the top, also 6 inches thick, and fired again, and
so on the whole day. If it be fired too mnch it becomes hard and too refractory to
work in the ma£9es. The glaze is worked in an OTen similar to the above. It may
be composed of about one-half borax and one-half of Cornish stone (partially decom-
poeed granite) in a yellowish powder procured from the potteries. This is fritted for
10 hours, and then fused into a glass which is ground up for the glase.
ENAMELLED LEATHER. Leather glazed upon one surface, the so-called
enamelling composition being in all respects analogous to the ordinary varnishes. In-
stead of enamelling the grain sarfeu^e^ as is usually done, Mr. Nossiter removes that
surface by splitting or buffing, and then produces what is called ** a finish *' upon the
surface thus formal, by means of a roller, or glass instrument The flesh side of the
skin may be thus prepared for enamelling; and it is less liable to crack, and the
enamel to become cloudy on it than the grain side. See Leatheb,
ENCAUSTIC PAINTING. A mode of painting with heated or burnt wax,
which was practised by the ancients. The wax, when melted, was mixed with as
mocJi colour, finely powdered, as it could imbibe, and then the mass was spread on
the wall with a hot spatula. When it became cold the designer cut the lines with a
cold pointed tool, and other colours were applied and melted into the former. Many
modifications of the process have been employed. Amongst the moderns, the term
has been improperly given to some cements, which have nothing of an encaustic
chamcter about them.
ENCAUSTIC TILES. See Ttleb and Tesssilb.
BNDOGEN0U& See EzuOEZvbus.
ENGRAVING, a word derived from cy, m, and y^duptt, to grave or write, is the
art of executing designs or devices, upon metal, stones, and other hard substances. In
the common acceptation of the woid in the present day, it means the execution of
soch works on plates of copper or steel, for the purpose of obtaining from them im-
pTKsions in ink or some other coloured fluid. Engraving, in the widest sense of the
term, is the oldest of the fine arts ; at least, the Scriptures mention it before any
reference is made either to painting or sculpture. In the Book of Exodus, ch. xxviii.
V. 29, we read that " Aaron shall bear the names of the children of Israel in the
breast-plate of judgment upon his heart ; " and again, in the same chapter, Moses is
commanded to ^ make a plate of pure gold, and grave upon it, like the engravings of
a signet. Holiness to the Lord." Further on, in the 35th chapter of the same book,
Moses speaks of Bezaleel, the son of Uri, as a man " filled with the spirit of God, in
visdom, in understanding, and in knowledge, and in all manner of workmanship ;
and to devise curious works, to work in gold, and in silver, and in brass, and in the
catting of stones," &c Of him and of Aholiab it is said, — ** Them hath he filled with
wisdom of heart, to work all manner of work of the en^ver," &c. &c. These
extracts will suffice to show the antiquity of the art of mcising, or cutting hard
substances; whether or not it had its origin at a period anterior to the time of Moses
there is no record, but it is not improbable that the Israelites acquired some knowledge
ot the art from the Egyptians during their lengthened captivity, an assumption
strengthened by the fact that numerous specimens of hieroglyphic engraving, on metal
plates and on stone, have been discovered in Egypt and brought to this country t
their dates, however, have not, in all cases, been ascertained with certainty.
It is unnecessary to trace back all that might be written respecting the state of this
art among the nations of antiquity in its various applications ; but as an example of
its adoption for a purpose altogether practical, a passage from Herodotus may be
adduced. This historian, referring to a period about 500 years before the Christian era,
says : — " Aristagoras exhibited to the king of Sparta a tablet, or plate, of brass, on
which was inscribed every part of the habitable world, the seas, and the rivers ; " or,
in other words, Aristagoras, who was a native of Cuma, had in his possession a
metallic map. Moreover, as it is intended to limit this notice to the art of en-
graving on steel or copper for printing purposes, we pass over those branches or
departments of the art Uiat relate to die-sinking, seal-engraving, and engraving on
coins, the latter a common process with the ancient Britons and Saxons, who also,
according to the opinion of many modem antiquarians, used to ornament their
weapons of war with designs cut by the graving-tool.
The transition from all previous methods of engraving, to that which in some degree
assimilates to what is now practised as the result of the discovery of printing, has been
thus described by the late Mr. Landseer, who quotes an earlier writer, Mr. Strutt : —
** Soon after the conquest (though, from other information, X think it must have been
at the least 250 years from that memorable era) a new species of engraving, entirely
k3
134 ENGBAVme.
different flrom the mingled work of the engrayer, goldsmith, and chaser, vbich had
preceded it, was introduced into, or invented in, England, of which there is icareelj
an old country church of any consequence, but affords some curious specimens, aad
England more than any other nation in Europe. The brass plates on oar dd
sepulchral monuments are executed entirely with the grayer, the shadows beiii^
expressed by lines or strokes, strengthened in proportion to the required depth of
shade, and occasionally crossed with other lines a second and, in some instanoo, a
third time, precisely in the same manner as a copper plate is engrayen thst is is*
tended for producing impressions. These engraved efSgies are commonly foinid on
those horizontal tombstones which form parted the pavement within the chnrehes;aod
the feet of the congregation, which kept the lights bright by friction, filled the in-
cisions with dust, and thus darkened the shades : very neat or exquisite workmanship
is not therefore expected ; yet some of them bear no small evidence of the abilities
of the monks, or other workmen, by whom they were performed." Impressioss,
technically called ** rubbings," are taken from these monumental brasses by antiqaa-
rians, for the purpose of ulustrating works in archseology. The process is simple
enough ; a sheet, or sheets, as may be required, of white paper, sufficiently large to
cover the brass tablet, are laid upon it ; these are then rubbed over with a lump of
*» shoemaker's heel -ball," a composition of wax and lamp-black, which leaves on the
paper an impression of the raised portions of the metal.
The fifteenth century, which must always be considered as the dawn of anirenal
light and knowledge, gave to the world the art of printing, and from this ioTentios
arose a new era in the art of engravins;: the earliest method of printing, both boob
and illustrations, was, as is described under the article Wood Engraving ^ from engraTed
blocks or tablets. It seems singular that, though engraving on various metals had
been practised long before that on wood, no attempt had ever been made to obtain
impressions fh>m the plates ; like many other important discoveries, this is said to be
the result of accident Vasari, the historian of Italian art, says that, in the year 1460,
Maso, or Thomaso Finiguerra, a Florentine goldsmith, chanced to let flail a small
engraved plate, on which, as was customary with engravers, he had rnbbed a little
charcoal and oil, that he might the better see the state of his work, into some melted
sulphur, and observing that the exact impression of his engraving was left on the
sulphur, he repeated the experiment, by passing a roller gently over it It was suc-
cessful, and Finiguerra imparted his discovery to Baldini, also a goldsmith of Florence,
by whom it was communicated to others. But the most probable origin of the art of
printing from metallic plates, is that which is attributed to the early Italian workers
m ni«//o, or inlaid modeling work, an art used for ornamenting table utensils, swords,
armour, fitc : this art consisted in cutting or engraving the required design on silver,
and filling up the incisions with a black composition, said to be made of silver and lead,
which, from its dark colour, was called by the ancients nigellum, abbreviated by the
Italians into niello; this mixture, when run into the engraved lines, produced a regular
effect of chiar-oscuro in the entire work. From these engraved pUtes or objects, the
artists in ntW/o, who were the goldsmiths and silversmiths of that perod, were accns*
tomed to take impressions, by smoking the metal, and then, after cleaning the smoo^
surface with oil, impressing upon it a piece of damp paper. From such an origiui or
from some other very similar to it, undoubtedly, came the art of chalcography, or
plate-printing, and it is equally certain, that the art of engraving with the bmn, or
as it is now called, " line engraving," arose in the workshops of the gold and 8ilve^
smiths.
The practice of making paper from rags, without which the former art would hare
proved comparatively useless, had been adopted generally throughout Europe towards
the end of the fourteenth century, whereby the chief obstacle to printing was remored.
Not very long after the discovery of plate-printing, the engravers, separating them-
selves from the manufacturing goldsmiths and chasers, formed thenselves into a dis-
tinct body, opened schools for pupils, and took up their rightful position among the
artists of the time.
Italy and Germany have each contended for the hononr of being the first discoverers
of the art of printing from engraved plates, but the best authorities give to the former
country the priority of claim, though the Germans, to whom the printing prew J^
earliest known, soon surpassed their rivals, both in that art and in engraving : buttney
have not always maintained the superiority.
The principal Italian engravers, contemporary with, or immediately following ^^^J
guerra, were Baldini, Botticelli, and Andrew Mantegna ; in Germany, the names oi
Martin Schon, who began his career about the year 1460, and engraved his own com-
positions, Israel Van Mecheln, Leydenwurf, and Wolgemup, stand prominently forwaw;
but it was not till the commencement of the sixteenth century, that engraving occupie**
a high position among the arts of either country. Singularly enough, Italyt GcrmaoT*
ENGRAVING. 135
and HoUand, produced each an engraver, whose -works to this day are held in the
highest estimation ; while Marc Antonio Raimondi (bom at Bologna, in 1488), and
Albert Dnrcr (bom at Nuremberg, in 1471), were respectively practising the art in
Italy and Germany, Lucas Van Leyden (bom at Leyden, in 1494) disputed in the
Low Countries the palm with these distinguished competitors. As these artists have
ever been considered the patriarchs of engraving, a few words respecting the merits of
each may not inappropriately be introduced here.
Travelling to Venice for improvement. Marc Antonio saw there some prints, by
Albert Durer, of Uie life of the Virgin ; these he copied with tolerable fidelity ; he soon,
however, quitted Venice, and went to Rome, where he made the acquaintance of
Raffaelle, a large number of whose works he engraved. ** The purity of his outlines,"
says Bryan, ** the beautiftil character and expression of his heads, and the correct
drawing of the extremities, establish his merits as a perfect master of design.*' His
works fi'equently exhibit a deficiency in reflex light and harmonv of chiar-otcuro^ and
he appears to have been ignorant of the principles of rendering local colour, or tints,
in the abstract ; neither did he attempt, or else was unable, to express the various
textures of substances : these are, however, minor defects by comparison, and may
easily be excused when the state of art generally at that period is taken into account.
** Raffaelle," says Landseer, ** was Marc Antonio's object ; and the blandishments, the
splendour, and the variety which would have been indispensably necessary to the
translation of Gorreggio or Titian, were not called for here."
Albert Durer, the head of the German school of engraving, laboured under disad-
vantages with which the artists of Italy had not to contend : the latter had frequently,
if not constantly, the graceful forms and flowing outlines of antique sculpture made
fi&miliar to them : and hence their works exhibit, even from the earliest time, much
greater elegance of manner, and refinement in execution, than those of Germany.
The engravings by Durer, whom Landseer supposes to be the first who corroded his
plates with aqua'fortis^ partake largely of the stiff, dry, and gothic manner, peculiar
to the country and the period, and which to this day is more or less discernible in
German art If Durer had been so fortunate as to have had the pictures of Raffaelle
to engrave, he would doubtless have left the world prints of a very different character
than those we now see : we should have had more grace of expression, and freedom
of lines, but less originality in the style of execution, and, probably, less vigour.
Durer engraved only his own designs, and his faults or defects were those of his
time : but, notwithstanding his Gothic bondage, nothing that has ever appeared in
more recent periods, surpasses, in executive excellence, his '* St Jerome seated in a
Room;*' here all the objects are rendered with a fidelity, that only the camera could
emulate. That very remarkable and mysterious composition known as ** The Death's
Head,** is also a masterly example of execution : the helmet, with all its pomp of
heraldic appendage, and the actual and reflex lights on its polished surface, are
characteristically, though minutely, expressed : the skull is accurately drawn, and
its bony substance unmistakably described. The head of the Satyr, with its beard
and wild redundance of snaky tangled hair, has considerable and well-managed
breadth of light and shade : the drapery of the female, quaiDt as it is in style, is not,
as we see it in Durer's other works, hard, stiff, and formal, but relaxes into freedom
and simplicity, and has quite a silky texture ; in fact, it approaches very nearly to
what we now call " picturesque composition of forms, and light and shade." Dcrer's
etching appears to have been bitten in, or corroded with the acid, at once. He seems
either not to have known, or did not care to practise, the process now adopted, of
" stopping out," for the purpose of producing gradation of shade. The admirable
wood engravings by this artist are referred to in their proper place.
The works of Van Leyden, the Dutchman, are even more gothic in taste and style
than those of Durer, with whom he is said to have been intimately acquainted : they
exhibit the same amount or degree of stiff, angular drapery; as much, perhaps
even more, inattention to grace and dignity of form, without his fertile imaginatioa,
his occasional vigour, and his truthfiil observation of individual nature. His execution
is neat and clearly defined, but his plates are deficient in firmness and harmonious
effect, and his lines are without variation in substance ; those that represent near
objects, and those that express objects at a distance, aro equally fine and delicate ; hence
the monotony apparent in his prints. They are almost entirely sacred or legendary
subjects, from his own designs; among the finest are ** The Temptation of St Anthony,
engraved in 1509, when he was only thirteen years of age; ** The Crucifixion," and
the ** Adoration of the Magi."
It would be beyond the province of this notice to record the progress of the art
through the continental schools till it took root in England; yet a short history of its
introduction and growth on our soil, may not be considered out of place.
Until the mid<Ue of the last centtuy, neither painting nor engraving had attained
K4
136 ENGRAVING.
any eminence in this coantiy ; the latter art, especially, was practised chiefly by
foreigners, as Hollar, Simon, Vaillant, Blooteling, &c. ; previously to whom ve had,
of our own countrymen, Faithorne, an admirable engraver of portraits, Payne, White,
and one or two others of inferior merit ; but, with the exception of Faithorne, none
whose works are now held in much esteem. The enconragement afforded by George
III., almost as soon as he ascended the throne, to the fine arts generally, and the
establishment of the Royal Academy, which offered to artists a position in the coontrj
they had never before neld, gave an impulse to every section, or branch, of art pro-
fessors. Hogarth's name had, however, become widely known many years before :
his numerous plates, all of them from his own designs, are to this day much sought
after, not so much, perhaps, for any especial excellence as examples of fine engrav-
iiigs, as for the talent and genius which the subjects display. ** Hogarth composed
comedies as much as Moliere," was the remark of Walpole : he died just as art was
beginning to be recognised and patronised in England. Francis Vivares, a French-
man by birth, but long settled in England, where he studied the art under Chatelain,
carried landscape-engraving to a high point of excellence ; some of his prints after
pictures by Claude and Gaspar Poussin, exhibit remarkable freedom in the foliage
of the trees, and truth in the texture of the various objects introduced in the
landscape. WooUett, bom at Maidstone, in Kent, who died in 1785; and Sir
Robert Strange, a native of one of the Orkney islands, who died in 1792, ad-
vanced the art still further; indeed, it is a question whether engraving has ever
found more able exponents than these two disting^hed men : the latter engnrtd
several portraits, which have rarely been surpass^ at any period in the history of
art The works of both these engravers are characterised bv bold and Tigorons
execution, produced by the combined use of the etching-needle and the gimver.
Cotemporary with these, or their immediate successors, were Browne, who some-
times worked with WooUett, Bartolozzi, Hall, Booker, Green, Ryland, Watts* Sharp,
Mc Ardell, Smith, Earlom, &c. ; all aided, by their proficiency, to uphold the booonr
of the art ; while John Landseer, father of uie living painters, Baimbach, Eng-leheart,
Pye, and John Burnet, — the last two yet with us, — may be regarded as the chief
connecting links between the past generation and the present
Engraving on metal plates may be classed under the following heads: — J^tcAia^,
line, mezzotintOt chalkt stipple, and aquatint Before describing the processes of work-
ing these respective kinds, a notice of the instruments used by the engraver is neces-
sary. These, with some modifications, are employed in all the styles.
The etching^point, or needle, is a stout piece of steel- wire inserted into a handle ; two
or three, varying in thickness, are requisite, and they should be frequently and care-
fully sharpened. This is best done by turning the needle round in the fingers while
rubbing it on a hone, and afterwards on a leather strop prepared with putty powder,
or on an ordinary razor-strop, to take off any roughness, and to make it perfectly
round.
The dry-point is a similar instrument, used for delicate lines: it must be sharpened
on the hone till a fine conical point is obtained.
The graver, or burin, is the principal instrument employed in engraving : several
are required, differing from each other in form, from, the extreme lozenge shape to the
sqmire; the former being used for cutting fine lines, the latter for broad: the grsTer
fits into a handle about five inches and a half long, and it should be well-tempered
before using, an operation requiring great care. The angle at the meeting of the two
lower sides is called the belly, and the breadth of the end, the face. To sharpen the
former, lay one of the flat sides of the graver on the oilstone, keeping the right arm
tolerably close to the side, and rub it firmly; next rub the other in the same way:
the face is sharpened by holding it firmly in the hand, with the belly upwards, in a
slanting direction ; rub the end rather gently on the stone, at an angle of about forty-
five degrees, taking care to carry it evenly along until it acquires a very sharp pciint:
this being done, hold the engraver a little more upright to square the point, which a
Tery few rubbings will effect The graver for line work must be slightly turned up,
to enable the engraver to run it along the plate ; otherwise the first indentation be
makes on the metal would cause his instrument to become fixed : the graver for
stipple should be slightly turned down, to make dots only.
The scraper, which should have three fluted sides, is used for taking off the fricrr
left by the action of the needles on the metal.
The burnisher is employed to soften lines that have been bitten in, or engraved too
dark, and to polish the plate, or get rid of any scratches it may accidentally have
received.
The dabber used to lay the etching -ground evenly, is made by enclosing a small
quantity of fine cotton wool very tightly in a piece of silk, the threads of which
should be, as much as possible, of uniform thickness.
ENGRAVING. 137
There are a few other materials which an engraver should have at hand, bat they
are not of sufficient importance to be mentioned here ; ire may, however, point out
what is technically called a bridge, which is nothing more than a thin board for the
hand to rest on ; it should be smoothly planed, and of a length and breadth in pro-
porti<m to the sise of the plate; at each end a small piece of wood should be fastened
to raise it above the plate when covered with wax. A blind, made of tissue-paper
stretched upon a frame, ought to be placed between the plate and the light, to enable
the engraver to see his work on the metal with greater facility and clearness.
In describing the processes of engraving the various styles enumerated above, little
more tiian a general outline of each method can be given, yet sufficient, it may be
presmned, to show the nature of the operation : to narrate all the details that might
be included in the subject would supply matter enough for a small volume.
EicluRg may be claned under two heads ; that which is made the initiatory process
in line-engraving, and that which is known as painUr^a-eteking ; the latter was prac-
tised to some extent by very many of the old painters, particularly those of the
Dutch school ; and it has also recently come into fashion with many of the artists of
our own day, but more for amusement, however, than for any other purpose ; in
both cases the method of proceeding is alike. Etching is the result of a chemical
process resulting in corrosion of the metal on which the design has been laid down,
or transferred, in the following manner. The plate must first be covered with a sub-
stance already spoken of as etching- ground, which may be purchased of most of the
inincipal artists' oolourmen, but many engravers niake their own : the annexed
receipt has been handed to us by Mr. C. W. Sharpe, who has engraved some (^ the
largest steel-plates published recently, as that which he always uses : —
Parti
Black pitch 1
White wax 1
Burgundy pitch --------f
Asphaltum ---------i
Gum mastic ---------i
Melt the first three ingredients over a slow fire in a pipkin, then add the other two
finely powdered, stirring the whole together all the time ; when well mixed, pour it
into warm water, and nuike it up, while warm, into balls ; if too soft, a little less wax
should be used. Care must be ta^en not to let the mixture bum during the process
of making.
The etching-ground resists the action of the aqua-fortis. It should be tied up in a
piece of strong silk, and applied thus, which is called laying the ground : — Take the
plate firmly in a small hand vice ; hold it, with the polished face upwards, over a
eharooal fire that it may not get smoked, till it is well, but not too much, heated : rub
the etching-ground, in the silk, over the plate till it is evenly covered ; the wax,
melting with the heat, oozes through the silk. To effect a more equal distribution
of the ground, take the dabber and £eib the plate gently all over, till it appears of an
uniform colour ; continue the dabbing till the plate begins to cool, but not longer.
The ground is Uien blackened by being held over the smoke of a candle, or two or
three tied together, — wax is fbr preferable to tallow ; keep the plate in motion, so
that every part be made equally dark, and also to avoid ii^ury, by burning, to the
composition ; when cold the plate is ready to receive the design. To transfer this, a
very correct ontline of the subject is made with a black-lead pencil on a piece of thin
hard paper: ihsten the tracing, or drawing, at the top edge, with its face downwards,
on to the etching-ground, with a piece of banking-wax, described hereafter, and by
passing it through a printing-press — such as is used by plate printers, to whom it
should be taken — the drawing is transferred to the ground. The bridge being laid
over the plate, the process of etching may now be commenced ; the points, or needles,
which are used to complete the design, remove the ground from the metal wherever
they pass, and expose Uie latter to the action of the acid during the process of what
is termed biting m. The needles with the most tapering points should be used for the
skies and distances, changing them for others for the foreground, which generally re-
qaires broader and deeper lines. Any error that has been made may be remedied by
covering the part evenly with the etching-ground mollified by spirits of turpentine,
using a camel's-hidr pencil for the purpose ; and, when dry, the lines may be re-
etched through it
The next operation is that of biting in, performed thus : — A wall or border of bank-
ing'weue is put round the edge of the plate : this wax, called sometimes bordering wax,
is made by melting over a slow fire, in a glazed pot, two parts of Burgundy pitch, and
one of bees- wax, to which is added when melted, a gill of sweet oil ; when cold it is
quite hard, but by immersion in warm water it becomes soft and ductile, and must be
138 ENGRAVING.
applied in kids state ; it will adhere to the metal hj being firmlj- prened down with
the hand : the object in thus banking up the plate is to prevent the escape of the
acid which is to be applied ; but a spout or gutter must be left at one comer to poor
off the liquid when necessary. Mr. Fielding, — to whose work on the art of engraTing
we are indebted for some of the practical hints here adduced, availing ourselves,
however, of the improvements introduced into modem practice, — recommends the
following mixture as the best :^ " Procure some strong nitrous acid, and then mix, in
a wide mouthed bottle one part of the acid, with five parts of water, adding to it a
small quantity of sal ammoniac, in the proportion of the size of a hazel-nut to one
pint of acid, when mixed for biting. The advantage of using the sal ammoniac is,
that it has the peculiar property of causing the aqua fortistobite more directly down-
wards, and less laterally, by which means lines laid very closely together are less
liable to run into each other, nor does the ground so readily break up.** When the
mixture is cool — for the acid becomes warm when first mixed with water — poar it
on the plate, and let it continue there till the more delicate lines are presumed to be
corroded to a sufficient depth ; this will probably be in about a quarter of an hour ;
sweep off the bubbles as they appear on the plate with a camel's-hair pencil, or a
feather ; then pour off the acid through the gutter at the comer, wash the plate with
warm water, and leave it to dry. Next, cover those parts which are sufficiently
bitten in with Brunswick black, applying it with a camelVhair pencil, and leave it to
dry ; again put on the acid, and let it remain twenty minutes or half an hoar, to give
the next degree of depth required ; and repeat this process of stopping out and Inting
«n, until the requisite depths are all attained : three bitings are generally enough for a
painters etching. The work is now complete, unless the graver is to be used upon it,
and the banking- wax may be removed, by slightly warming the margin of the plate ;
and, finally, wash the latter with a soft rag dipped in spirits of turpentine, and
rubbing it with olive oiL If, when the plate is cleaned, the engraver finds that the
acid has acted as he wishes, he has secured what is technically termed ** a good
bite."
Steel plates require another method of biting-in, on account of their extreme hard-
ness, and liability to rust ; the mode just described is applicable only to copper,
the metal generally used by painters for their etchings. For steel plates mix
together
F^rto
Pyroligneous acid -------i
Nitric acid ---------i
Water 3
This mixture should not be allowed to remain on above a minute ; let it be washed
off at once, and never use the same water twice ; the plate must be set up on its edge,
and dried as quickly as possible to avoid mst : the acid may be strengthened where
a stronger tint is required.
debiting, a process frequently adopted to increase the depth of tint where it is re-
quired, or to repair any portion of a plate that has been worn by printing or acci-
dentally injured, is thus performed. The plate must be thoroughly cleaned, all traces
of grease removed, by washing it with spirits of turpentine and potass, and polished
with whitening; it is then, when warmed over a charcoal fire or with lighted
paper, ready for receiving the ground; this is laid by using a dabber charged with
etching-ground, and carefully dabbing the surface ; by this means the surface of the
plate only is covered, and the lines already engraved are left clear ; any part of the
plate that it may not be necessary to rebite, must be stopped out with Brunswick black,
and then the acid may be poured over the whole, as in the first process.
Etching on soft ground is a style of engraving formerly much practised in imitation
of chalk or pencil drawings ; since the introduction of lithography, however, it has
been entirely abandoned. The soft ground is made by adding one part of hog^s lard
to three parts of common, or hard, etching-ground, unless the weather be very warm,
when a smaller quantity of lard will suffice ; it should be laid on and smoked in the
manner already described. Mr. Fielding gives the following method for working on
it. ** Draw the outline of your subject faintly on a piece of smooth thin writing
paper, which must be at least an inch larger every way than the plate ; then damp it,
and spread it cautiously on the ground, and turning the edges over, paste down to the
back of the plate ; in a few hours the paper will ^ dry, and stretched quite smooth.
Kesting your hand on the bridge, take an H or HB pencil, and draw your subject on
the paper exactly as you wish it to be, pressing strongly for the darker touches, and
more lightly for the delicate parts, and, accordingly as you find the ground more or
less soft, which depends on the heat of the weather or the room you work in, use a
softer or harder pencil, remembering always that the softer the ground the softer the
ENGRAVING. 139
pencil " (should be), ** When the drawing is finished, lift up the paper earefoU j fh>m
the pbte, and wherever yon have touched with the pencil, the ground will stick to
the paper, leaving the copper more or less exposed. A wail is then put round the
margin, the plate hit in, and if too feehle, rebit in the same way as a common etching,
using Aorc/ etchmg-ground for the rebite."
jMe emgraving unquestionably occupies the highest place in the category of the art \
and, taking it as a whole, it is the most suitable for representing the various objects
that constitute a picture. The soft, pulpy, and luminous character of flesh ; the rigid,
hard, and metallic character of armour ; the graceful folds and undulations of draperies,
the twittering, unsteady, and luxuriant foliage of trees, with the bright yet deep-toned
colour of skies, have by this mode, when practised by the best engravers, been more
suoceasfhlly rendered than by any other. The process of line-engraving is, first, to
etch the plate in the manner already described, and ^^rwards to finish it with the
graver and dry point. An emfraver'a etching differs from a painter*$ etching in that
erery part of Uie work has an unfinished appearance, though many engravers, espe-
cially of landscapes, carry their etchings so fbr as to make them very effective :
engravers ot historical and other figure subjects, generally, do little more than etch
the outlines, and the broad shadowed masses, or colours, of the draperies ; the flesh
being entirely woi^cd in with the burin, or graver : no definite rules can be laid
down as to the extent to which the etching should be advanced ere the work of the
tool conunences, as scarcely two engravers adopt the same plan precisely: much
must always depend on the nature of the subject Neither would it be possible to
point out in what particular way the graver should be used in the representation of
any pardcular object : this can only be learned in the studio of the master, or by
Btuidying the works of the best engravers : as a rule it may be simply stated, that in
making the incision, or line, the graver is pushed forward in the direction required,
and should be heU by the handle, at an angle very slightly inclined to the plane of the
steel or copper plate : the action of the graver is to cut the metal clean out.
Within the last few years an instrument, called a ruling nuichine, has been brought
into nse for laying in flat tints in skies, buildings, and objects requiring straight, or
slightly curved lines : considerable time is saved to the artist by its use, and more
even tmts are produced than the most skilful hand-work, generally, is able to effect ;
bat to counterbalance these advantages, freedom is frequently sacrificed, and in
printing a large number of impressions, the machine>work, unless very skilfully
ruled in, is apt to wear, or to become clogged with ink, sooner than that which is
graved.
Mezzotinta engroiring is generally supposed to owe its origin to Colonel Ludwig von
Siegen, an officer in the service of the Landgrave of Hesse; there is extant a portrait
by him, in this style, of Amelia, princess of Hesse, dated 1643. Yon Siegen is said
to have communicated his invention to Prince Rupert, to whom many writers have
assigned the credit of originating it : there are several plates executed by the Prince
still in existence. It differs from every other style o( engraving, both in execution
and in the appearance of the impression which the plate yields : a mezzotint engraving
resembles a drawing done in washes of colour, by means of a camelVhair pencil,
rather than a work executed with any sharp pointed instrument : but a pure mezzo-
tint engraving is rarely produced in the present day, even for portraits ; the advan-
tages derived from combining line and stipple, of which we shall speak presently,
with it, to express the different kinds of texture in objects, have been rendered so
obvious as almost to make them necessary : this combination is termed the mixed
styU. The distinguishing excellences of mezzotint are the rich depth of its shadows,
an exquisite softness, and the harmonious blending of light and shade : on the other
hand, its great defect is the extreme coldness of the high lights, especially where they
oeeur in broad masses.
The instruments used for this kind of work are, Inamishers, scrapers, shading too/s^
roulettes, and a cradle, or rocking tool. The burnisher and scraper differ in form from
those already described : the roulette is used to darken any part which may have been
scraped away too much ; it ought to be of different sizes : the cradle is of the same
form as the shading tool, and is used for the purpose of laying grounds.
The operation of engraving in mezzotint is precisely the opposite of that adopted
in all other styles : the processes in the latter are from light to dark, in the former
ftom dark to light, and is thus effected. A plate of steel or copper is indented all over
its face by the cradle, an iostrument which somewhat resembles a chisel with a toothed
or serrated edge, by which a burr is raised on every part in such quantities that if
filled in with ink, and printed, the impression would exhibit a uniform mass of deep
bbkck : this operation is called laging the ground; it is performed by rocking the cradle
to and fro, and the directions, or ways, as the engravers call them, are determined by
a plan, or scale, that enables the engraver to pass over the plate in almost any number
140 ENGRAVING.
of direcUons without repeating any one ef them. When an outline of the sulgect
has been first etched in the ordinary way before the ground is laid, the engraver pro-
ceeds to scrape away, and then burnish the highest lights, after which the next lightest
parts are similarly treated, and the process is repeated after this manner till the work
is finished ; the deepest shades are produced from the ground that is left untouched.
There is, however, no style of engraving for the execution of which it is so diffiealt
to lay down any definite rules, for almost every engraver has his own method of
working.
Chalk or gtipple engraving, for the terms are synonymous, is extremely simple.
The plate has first to be covered with the etching ground, and the subject transferred
to it in the ordinary way : the outline is then laid in by means of small dots made
with the stipple graver ; all the darker parts are afterwards etched in dots lai^er and
laid closer together. The work is then bitten in vrith the acid; and the ground being
taken off, the stipple graver must again be taken up to complete the operation ; the
light parts and the dark are respectively produced by small and large dots laid id
more or less closely together. Stipple is well adapted for, and is often used in, the
representation of flesh, when all the other parts of the subject are executed in line:
hence it is very frequently employed in portraiture, and in engravings from sculpture.
Chalk engraving is simply the imitation of drawings in chalk, and is executed like stipple,
only that the dots are made with less regularity, and less uniformity of size ; in the
present day, the two terms are generally considered as expressing the same kind of
work.
Aquatint engraving^ which represents a drawing in Indian-ink or bistre even more
than does mezzotint, has been almost entirely superseded by lithography, and still
more recently by chromo-lithography ; and there seems little probability that it will
ever come into fashion again. This being the case, and as any detailed description
of the mode of working would, to be of any service, occupy a very considerable space,
it will, doubtless, be deemed sufficient to give only a brief outline of its character and
of the mode of operation ; this we abbreviate from the notice of Mr. Fielding, for-
merly one of our most able engravers in aquatint. The process consists in pouring
over a highly polished copper plate a liquid composed of resinous gum, dissolved in
spirits of wine, which latter, evaporating, leaves the resin spread all over the plate in
minute grains that resist the action of the aquafortis, which, however, corrodes the bare
surface of the copper that is left between them : this granulated surface is called a gromd.
The ground having been obtained, the margin of the plate should be varnished over,
or stopped out, and, when dry, the subject to be aquatinted must be transferred to the
plate, either by tracing or drawing with a soft black4ead pencil, which may be used
on the ffround with nearly the same facility as paper; if the former method be adopted
the tracmg must be carefully fastened down to the copper by bits of wax along the
upper edge. A piece of thin paper, covered on one side with lamp-black and sweet
oil, is placed between the tracing and the ground, with the coloured side downwards,
and every line of the subject must be passed over with the tracing point, using a
moderate pressure. The tracing being finished and the paper removed, a wall of
prepared wax, about three quarters of an inch high, must be put round the plate,
with a large spout at one comer, to allow of the acid running off.
The plate is now ready for use ; and the completion of the design is commenced by
stopping out the highest lights on the edges of clouds, water, &c., with a mixture of
oxide of bismuth and turpentine varnish, diluting it with spirits of turpentine till of a
proper consistence to work freely. Next pour on the acid, composed of one part of
strong nitrous acid and five parts of water ; let it remain, according to its strength,
from half a minute to a minute, then let it run off, wash the plate two or three times
with clean water, and dry it carefully with a linen cloth. This process of stopping
out and biting in is continued till the work is complete ; each time the aquafortis is
applied a fresh tint is produced, and as each part successively becomes dark enough
it is stopped out; in this manner a plate is often finished with one ground bitten in
ten or twelve times. We would recommend those who may desire to become thoroughly
acquainted with this very interesting yet difficult mode of engraving to consult Field-
ing's Art of Engraving,
A few remarks explanatory of the method of printing steel or copper plates seem to be
inseparable from the subject. The press used for the purpose consists of two cylinders
or rollers of wood, supported in a strong wooden fhune, and movable at their axes.
One of these rollers is placed just above, and the other immediately below, the plane
or table upon which the plate to be printed is laid. The upper roller is turned round by
means of cogged wheels fixed to its axis. The plate being inked by a printer^s inking-
roller, an operation requiring great care, the paper which is intended to receive the
impression is placed upon it, and covered with two or three folds of soft woollen stnff
ENGRAVING. 141
like blanketing. These are moved along the table to the spot where the two rollers
meet ; and the npper one being turned by the handle fixed to the fiy-wbeel, the plate
passes throagh it, conTeying die impression as it moves ; the print is then taken off
the plate, which has to undergo the same process of inking for the next and every
sDCceeding impression. The jfrcoft of an engraved plate are always taken by the
most skilfal workmen in a printing establishment ; in the principal houses there are
generally employed from two to six men, according to the amount of bnsiness trans-
acted, whose duty it is to print proof impressions only; they are called prooers* A care-
ful, steady workman is not able to print more than Arom 180 to 300 good ordinary
impresnonsirom a plate, the subject of which occupies about seven inches by ten inches,
even in what is considered a long day's work, that is, about fourteen hours ; the prover^
from the extreme care required in inking the plate, and from the extra time occupied in
wiping it, and preparing the India-paper, will do from thirty to forty, according as the
subject of the plate is light or heavy. This difference in the cost of production, taking
also Into account that &e proofs are worked off before the plate has become worn,
even in the least degree, and that very few proofs, compared with the ordinary prints,
are generally struck off, is the reason why they are sold at a price so much greater than
the latter.
Notwithstanding the vast multiplication of engravings within the last few years, it
is generally admitted, by those best acquainted with the present state of the art, that
it is not in a healthy condition. The highest class of pictorial subjects — ^history, and
the highest style of engraving — line, have given place to subjects of less exalted cha-
racter, and to a mixed style of work, which, however effective for its especial purpose,
is not pure art. The pictures by Sir R Landseer have gained for engravings of such
subjects a popularity that has driven almost everything else out of the field, and have
created a taste in the public which is scarcely a matter of national congratulation. We
have engravers in the country capable of executing works equal to whatever has been
piYNinced elsewhere at any time, but their talents are not called into requisition in such a
way as to exhibit the art of engraving in its highest qualities. Publishers are not
willing to risk their capital on works which the public cannot appreciate, and hence
their windows are filled with prints, the subjects of which, however pleasing and
popular, are not of a kind to elevate the taste ; while the conditions under which en-
gravers generally are compelled to work, offer but little inducement for the exercise
of the powers at their command. Engraving on copper is in the present day but rarely
attempted ; formerly nothing else was thought of ; now the demand for engraving is
so great that copper, even aided by the electrotype, is insufficient to meet its require-
ments. In consequence of the comparatively small number of impressions which it
yields, a copper-plate will seldom produce more than .liOO or 600 good prints ; we have
known a steel, with occasionally retouching, produce more than 30,000, when well
engraved, and carefully printed ; very much depends on the printer, both with regard
to the excellence of the impression and the durability of the plate. The public demand
18 for prints both large and cheap, and to obtain this result, the engraver is too often
obliged to sacrifice those qualities of his art which under other circumstances his work
would exhibit Such is the state of engraving with us now. There are few, even of
the best artists we have, who by their utmost efforts can earn an income equal to
that of a tradesman in a small but respectable way of business. This is an evil to be
deplored, for it assists to deteriorate the art by forcing the engraver to labour hard for
a maintenance, instead of placing him in a position that would enable him to exalt the
art and his own reputation at the same time.
A process of depositing steel upon an engraved copper-plate has recently been brought
over to this country from France. M. Joubert, a French engraver long settled in
England, has introduced it here ; he has informed us that a copper-plate iSbus covered
may be made to yield almost any number of impressions, for as the steel coating be-
comes worn it can be entirely taken off, and a new deposit laid on without injury to the
engraving, and this ma^ be done several times; M. Joubert has repeated the experi-
ment with the most satisfactory results. He thus describes his process in a commu-
nication made to the Society of Arts, and printed in their journal : —
**' If the two wires of a galvanic battery be plunged separately into a solution of
iron, having ammonia for its basis, the wire of the positive pole is immediately acted
upon, while that of the negative pole receives a deposit of the metal of the solution —
this is the principle of the process which we have named '* acierage.'*
** The operation takes place in this way : — By placing at the positive pole a plate or
sheet of iron, and immersing it in a proper iron solution, the metal will be dissolved
under the action of the battery, and will form an hydrochlorate of iron, which, being
combined wilh the hydrochlorate of ammonia of the solution, will become a bichlo-
ride of ammonia and iron; on a copper plate being placed at the opposite pole and
142 ENGRAVING.
likewise immersed, if the solatioD be properly satarated, a deposit ot iron, bright and
perfectly smooth, is thrown upon the copper^plate, from this principle : —
" Water being composed of hydrogen and oxygen :
" Sal ammoniac being composed of : —
" 1st. Hydrochloric acid containing chlorine and hydrogen ;
** 2nd. Ammonia, containing hydrogen, nitrogen, and oxygen :
" The water is decomposed under the galvanic action, and the oxygen fixes itself
on the iron plate, forming an oxide of iron ; the acid hydrochloric of the soliition
acting upon this oxide becomes a hydrochlorate of iron, whilst the hydrogen preci-
pitates itself upon the plate of the negative pole, and, unable to combine with it, comes
up to the surface of the solution in bubbles.
** My invention has for its object certain means of preparing printing sorfaees,
whether for intaglio or surface printing, so as to give them the property of yielding
a considerably greater number of impressions than they are capable of doing in their
ordinary or natural state. And the invention consists in covering the printing sur-
faces, whether intaglio or relief, and whether of copper or other soft metal, with a
very thin and uniform coating of iron, by means of electro-metallurgical processes
And the invention is applicable whether the device to be printed from be produced by
engraving by hand, or by machinery, or by chemical means, and whether the snr^
face printed fh>ra be the original, or an electrotype surface produced therefrom. I
would remark that I am aware that it has been before proposed to coat type and
stereotypics with a coating of copper, to enable their surfaces to print a larger number
of impressions than they otherwise would do ; I therefore lay no claim to the general
application of a coating of harder metal on to the surface of a softer one, but my
claim to invention is confined to the application of a coating of iron by means of
electricity on to copper and other metallic printing surfaces.
" In carrying out the invention I prefer to use that modification of Grove's battery
known as Bunsen*s, and I do so because it is desirable to have what is called an in-
tensity arrangement The trough I use for containing the solution of iron in which
the engraved printing surface is to be immersed in order to be coated is, lined with
gutta percha, and it is 45 inches long, 22 inches wide, and 32 inches deep. In pro-
ceeding to prepare for work, the trough, whether of the size above mentioned or
otherwise, is filled with water in combination with hydrochlorate of ammonia (sal
ammoniac) in the proportion of one thousand lbs. by weight of water to one hundred
lbs. of hydrochlorate of ammonia. A plate of sheet iron, nearly as long and as deep
as the trough, is attached to the positive pole of the battery and immersed in the sola-
tion. Another plate of sheet iron, about half the size of the other, is attached to the
negative pole of the battery, and immersed in the solution, and when the solution has
arrived at the proper condition, which will require several days, the plate of iron
attached to the negative pole is removed, and the printing surface to be coated is at*
tached to such pole, and then immersed in the bath till the required coating of iron is
obtained thereto. If, on immersing the copper plate in the solution, it be not im-
mediately coated with a bright coating of iron all over, the bath is not in a proper
condition, and the copper plate is to be removed and the iron plate attached and
returned into the solution. The time occupied in obtaining a proper coating of iron
to a printing surface varies from a variety of causes, but a workman after some ex-
perience and by careful attention will readily know when to remove the plate from
the solution ; and it is desirable to state that a copper plate should not be allowed to
remain in the bath and attached to the negative pole of the battery after the bright
coating of iron begins to show a blackish appearance at the edges. Immediately on
taking a copper plate from the bath ^eat care is to be observed in washing off the
solution from all parts, and this I beheve may be most conveniently done by causing
jets of water forcibly to strike against all parts of the surface. The plate is then
dried and washed with spirits of turpentine, when it is ready for being printed fh»m
in the ordinary manner.
** If an engraved copper plate be prepared by this process, instead of a comparatively
limited number of impressions being obtained and the plate wearing out gradually, a
very large number can be printed off without any sign of wear in £e plate, the iron
coating protecting it effectually ; the operation of coating can be repeated as many
times as required, so that almost an unlimited number of impressions can be obtained
ft'om one plate, and that a copper one.
*' This process will be found extremely valuable with regard to electrotype plates
and also for photogalvanic plates, since they can be so protected as to acquire the
durability of steel, and more so, for a steel plate will require repairing from time to
time, these will not, but simply recoating them whenever it is found necessary ; by
these means one electro copper plate has yielded more than 12,000 impressions, and
was found quite unimpaired when examined minutely." — J, D.
ENGRAVING. 143
ENGRAVING ON WOOD. The art of wood engraving is so intimately con-
nected with that of book-printing, that it is impossible to disseTer the one from the other,
inasmuch as the earliest books were printed from large woodcuts, the entire page,
text, and illustrations being engrared in one solid block. Hence the term " block-
books " given to these ancient works. The impression flrom these engraved pages is
generally taken in a thin ink, sometimes of a brown hue, which occasionally spreads
or blots on the lines or letters ; and the printing is generally supposed to have been
effected by friction on the back of the damped paper laid on the inked lines ; the
sheets so printed were afterwards pasted back to back, and thus formed consecutive
pages of the volume. Such books originated from the large wood-cuts of a devotional
cUus, which, in the early part of the 1 5th century, were spread by the clergy among
the common people, perhaps to counteract the evil produced by the use of playing
cards, which were also printed in large sheets of cuts, and severed afterwards; but on
this point typographical antiquaries are not agreed, ss dates and other evidence are
wanting to enable us to fix either time, or place, to these early productions. The
earliest wood-cut bearing a date is that belonging to Earl Spencer, and representing
Su Christopher carrying the Saviour across an arm of the sea; it has two lines of
text beneath it, and the date 1423 thus expressed *'millesimo cccc^ xx° tercio."*
The British Museum is possessed of some very early single-leaf wood- cuts: one repre*
senting Christ brought before Pilate, is executed in bold coarse outline, the figures
are very large, and retain the characteristic features of the drawings seen in manu-
scripts of the 14th century. Another undated cut is one of those fanciful inventions
-which the scholastic men of that early day delighted in constructing; it is termed
TurriM Sapiencit, every stone of which is inscribed with the name of some moral
virtue, the foundation buttresses being prudence, fortitude, justice, and temperance;
the windows which give it internal light being discretion, religion, devotion, and con-
templation. Another representing the seven nges of man, is supposed to be a work
of the middle of the 15th century. It was found pasted inside the covers of an old
book, a practice which has preserved many specimens of old engraving which would
else have been lost. On the opposite cover is a fragment of another large cut, repre-
senting the Virgin with St. Joachim and St. Anne. The St Christopher above named
was ducovered in the cover of a volume in the conventual library at Buxheim, in
Suabia. All these old wood-cuts, as well as the block books, are generally daubed
with flat tints of coarse colour, supposed to have been done with stencil plates, such
as the card painters used on some occasions; but evidently rudely executed by hand
in others. They are all precisely of the kind to attract the uneducated eye ; and to
this day similar coarse prints are used by the clergy to aid the devotions of the
peasants of the Germanic nations.
The most celebrated of the block books is that termed the BihUa Pauperum. Each
page is divided by architectural compartments into three subjects, from the Old and
New Testament, selected to form ** parallel passages " of sacred writ ; above and below
are other compartments with heads of the prophets, and in the intervening spaces,
or upon scrolls, are explanatory inscriptions. The page measures 10 inches by 7^,
and IS one of the most elaborate works of its class ; but it exhibits very small claims
to attention as a specimen of art, certainly less than the Cantica Canticorum, each page
of which is divided horizontally into two pictures, with slight descriptive lines on
scrolls ; or the Apoccth/psis SancU Johannes, which is similarly arranged, and in both
of which we occasionally find much power of drawing and ability of grouping. The
dates of these books can only be conjecturally given, but they are probably contem-
porary with the St Christopher, or but a few years later. Judging from general
characteristics the Apocalypte seems to be the earliest The figures are executed
entirely in outline, with no attempt at shadows, which appear sparingly on the St
Christopher, and are very freely introduced in the Canticles^ and still more abundantly
in the Biblia Pauperum, These effects are always produced by a series of short lines
laid parallel to each other, nor is any attempt made to enrich the meagre character of
the work by crossing the lines, as in more modem engraving. The debate, which has
excited so many historians as to the place where printing first had birth, hss included
many doubts concerning the country where these old block-books were fabricated ;
but from the armorial bearings which appear on the shields of some figures in the
Cantidesj Germany seems to be the country where that series was designed f; probably
* Voeh interest was excited some few years ago by the diacotery of a cut in the llbrniy at Brusseli ap-
parently tiearing ao earlier date ; but strict InvestigRtion has since proved that one of the C's In the date
nas been omitted ; this mali^ just one hundred years difTerence in its age. But the date thus altered is
quite in accordance with the general character of the design and execution of the cut, which, on the
contrary, do not at ali jwreo with the earlier date originally as&lRned to it.
t Among them is the doable.headed eagle of Austria, the blade eagle of GermanT, the three crowns
of Cologne, the cross-keys of Eatisl)on, the arms of Wurtemberg, Nymphenburg, and Alsace.
144 ENGRAVING.
Flanders or Holland may daim the BibliaPawpenm^ which does not bear equal traces of
refinement in art. The Speculum Humana Salvationu has been claimed for Laurence
Coster of Haarlem. Tbis book was a combination of block-book and movable type,
liaying long cuts across the top of each page, divided by columns into two sabje^
with moveable types beneath. It is not unosaal to meet with woodcut pages of type
alone at this period; and books with such pages, or with the addition of wood cats,
were produced by the old engravers after the invention of movable types ; bat, as
metal-cast letters speedily usurped the place of the wooden ones, the wood engravexs
seem to have soon confined themselves to the pictorial branch of the art
The love of pictured illustrations of narrative history gave a permanence to the
art of wood engraving, and the works printed in Italy, as well as those introdnoed
into Eneland by Caxton, were adorned with cuts. They are* however, of the
rudest kmd, with broad heayy lines, and were most probably produced from coarse
pen drawings made on the surface of the wood, and mechanically cut by the engraver.
Toward the close of the fifteenth century ** cross hatching " (as lines of shadow cross-
ing each other are technically termed) is first seen, and in the Nurembnrg Chronicle,
1493, they are freely used. The designers and engravers of these outs, perceiving
the effect, which may be so readily obtained in wood engraving, by leaving the wood
untouched with the graver for solid masses of shadow, have availed themselves of it,
and given stronger effect to their cuts thereby. Michael Wohlgemuth and William
Pleydenwurff were the designers employed; the former artist was the master of
Albert Durer, who ultimately raised wood engraving to the highest point of ex-
cellence.
Durer's first great work was a series of sixteen large cuts illustrative of the
Apocalypse. They were published in 1498, and attracted great attention from the
vigour and strange originality of their design, and the artistic character of their treat-
ment In 1511 another series of cuts was published at Nuremberg by Durer,
illustrative of the Apocryphal Life of the Virgin. They evidence the great improve-
ment which the artist had made during the interval, and are certainly the finest wood
cuts which had ever been executed up to that period ; but they are eclipsed by the
series of eleven large cuts published soon after, representing scenes in the Passion of
Christ ; and which may be fairly considered triumphs of the art of wood-engraving,
unsurpassed in design and execution by any successors. The art had now become
appreciated wherever it was known, and a host of wood engravers found employ in
Nuremberg, cutting the designs of Darer, Hans Burgmair, Hans Schanfelein, and
other artists ; who found no lack of patronage in the old imperial city, for the EUnpe-
ror Maximilian I., extensively employed them in various works illustrative of his real
or fancied exploits.*
So important was this royal patronage, that the engravers set no bounds to the sise
of the works they attempted, and hit upon the plan of joining one block of wood to
another, until in the engraving representing the triumphal arch in honour of this
emperor, a wood-cut was completed in this way, measuring ten feet hj nine. The
size is, however, not its only claim to attention, for it is throughout designed and en-
graved with the utmost care and beauty.
In all these cuts of the great masters of the art of wood-engraving, we only find the
name of the designer recorded ; thus, Durer, and others of his era, whose names
occur on cuts, were the designers and draughtsmen on the wood ; but the engraver
was considered in the light of a mechanician, and, except in a very few instances, his
name was not displayed. To fully understand this, it is necessary here to explain the
whole process of wood engraving at this time. A block of wood being prepared
from a perpendicular catting of pear-tree* upon the surface was made a drawing, in
which every line was delineated with pencil or reed-pen, exactly as the cat was
ultimately to appear ; the intervening spaces of plain wood between every line were
then cut away ; and in this manual dexterity consisted the whole merit of the engraver.
The abundance of cross-hatching so constantly found in old wood cuts, is explained
by the fact of this being the easiest and best mode for the draughtsman to employ in
getting his effects of light and shade ; the extreme labour it involves to the engraver
not bemg considered ; but when it is understood that each minute space has to be cut
down from each angle of the lines, and the centre entirely cleared out, some idea may
be formed of the labour required, when thousands of such squares occur on some of
Durer*s large cuts, independent of other work. The backs of some of these old blocks,
particularly those in the Triumphs of Maximilian, are marked with the names of the
engravers, and there is proof that women practised the art ; but it is not at all likely
* Such were the Adventures of the Knight Thuerdank, under which form the emperor was figured ;
** The Wtoe King," an equally flatt(>rinR picture of hit early education and actlont ; and the magnifiocot
•eriea of cuta, known m ** The Triumphs of Maximilian."
ENGRAVING. 145
that the artists who designed* and drew upon the wood these de8ig:ns, went through
the merely mechanical labour of engraving them.
The great impetus thus given to wood engraving*, kept it prominently before the
world during the whole of the sixteenth century, when the presses of the continent
continually brought forth a series of volumes remarkable for the beauty of the cuts
by which they were illustrated. This practice of the book-trade gave rise to a
series of artists known as " the little masters " of the German school, fh>m the small
size of their works; among whom the principal who connected themselves with
engrsTing on wood were Virgil Solis, Henry Aldegraver, the two Bebaims, Lucas
Cranach, Urse Graff, Albert Altdorffer, Jost Ammon, and Solomon Bernard.
In Italy, Ugo da Carpi practised with success, from the year 1518, the art of en-
graving on wood imitations of tinted drawings ; an art which originated with the
Germans, but which he much enlarged and improved. It consisted in a series of blocks
cut to imita^ patches of colour, and made to print over each other in gradations of
tint, until the chiaroscuro of a drawing was secured ; then the coarser and bolder
lines defining the whole design were printed oyer all, and a capital imitaUon effected
of the bold cartoons, consisting of vivid outline and broad washes of tint, used as first
sketches for their pictures and frescoes by the artists of that enL
A perfect rage for book illustration seems to have beset the printers soon after the
death of Durer. The most prolific artists who supplied their wants, were Jost Ammon
and Solomon Bernard : the foi mer executed a multitude of designs on every imagina-
ble subject ; the latter, equally prolific, devoted himself chiefiy to the illustration of
sacred or clasnc literature. The greatest publishers of such books were Sigismond
Feyeraband, of Frankfort-pn-the- Maine; Jean de Toumes, and Trechsel, of Lyons ;
and Plantyn, of Antwerp. From their presses issued a series of small yolumes, which
can only come under the generic title of ** picture books ; " for they were got up for
the sake of exhibiting the favourite art of wood-engraving, and only contain a few
descripCiTe lines of type beneath each cut. The cuts executed by Ammon are all
remarkable for correctness of drawing and vigorous effect ; those of Bernard are
less schoIasticaUy correct, but contain more evidence of grace and faincy. The de-
signs of these artists abound in books published between 1550 and 1580; but the
most admirable series were executed in a little volume published at Lyons, in 1538,
without the name of draughtsman or engraver, the Simtdackres de la Mcrt^ known
among bibliographers as the ** Lyon's Dance of Death" a collection of cuts which,
for minute beauty and perfection of design and execution, are completely unrivalled,
and have not been equalled by any modem copyistf This was the Augustan age of
book'illustration, which flourished in popular favour until the close of the sixteenth
century, when a minute tamenesSf in contradistinction to the vigour of the earlier en-
gravers, began to appear, and reached its culmination in such cuts as were given in
Nicolay's " Travels in Turkey ** (Antwerp, 1576).
Titian is said to have furnished designs for various woodcuts, particularly the
series of Costumes published at Venice in 1590; and a very large coarse cut of the
Destruction of Pharaoh and his host, more than four feet long, is said to have been
one among many of uncommon size executed from his designs, they were printed on
separate blocks, and then pasted together in the manner of wall-papers. One repre-
senting the sacrifice of Abraham is remarkable for the variously tinted inks in which
it is printed to exhibit gradations of distance.
Wood-engraving, in the early part of the seventeenth century, had sunk from its
high estate. The last great artist who had employed himself in connection with the
art was Hans Holbein, and we do not find a great name again conjoined with it until
the middle of that century, when Rubens employed Jeghers, of Antwerp, to engrave
some of his drawings on wood. The generality of woodcuts in books of this era,
rival in coarseness the older block-books; the wood-engravers seem to have sunk into
mechanical unassisted by good artists to furnish them with drawings. The art had
become vulgarised, its profession a trade, and the demand and supply scarcely better
than the requirements of the ballad printer desired. They weje ancillary to the
commonest uses of the press, and all art speedily vanished f^om the cuts manu-
factured probably at a very cheap rate for temporary use. Of this kind are the
* Durer's engraTlngs v^re to exceedingly popular, that they found their war all over Europe.
Raphael admhred them in Rome, and was induced to perpetuate his own designs by employing Marc
Antonio Raimondi to engrave them on metal under his own super intendeuce. So originated the
modem print trade. Durer's designs were so much in request, that Lucas van Leyden imiuted them
on copper, for sale to such persons as could not perceive the great difference between the vigorous ori-
ginals, aud his tame and disagreeable copies. Durer was ultimately obliged to apply for legal restrictions
against these pimcle*.
f The designs have been popularly ascribed to Holbein, and, apparently, with reason. An artist
named Hans Lutzelburgher, of Basle, has been coiyectured to have been the engraver, from the
initials H. L. on one of them. By this time it Lad become usual to append the initials of engravers to
woodcuts, as well as those of the designers.
Vot.IL L
146 ENGRAVINa.
cuts sprinkled tlirongh the English books of the time of James and Charles L It if
possible that the printers vere supplied with them from Germany and Flanders. It wis
customary to use woodcuts repeatedly, particularly if merely ornamental ; in this
way initial letters were reproduced as the stock in trade of the printing-office? * ; and
even scenes of adventure^ adopted unscrupulously for other events* to which there
was the slightest general resemblance. f The names of these ** wood-cutters" have
not descended to our time ; their works are widely scattered over general literature,
and it is not until the middle of the century that we meet with any instance of an
attempt to arrest the downward progress of the art Then, as we have previoudy
noted, Rubens, probably anxious to rival Durer, engaged Christopher Jeglier, of
Antwerp, to execute, under his own superintendence and at his expense, a series of
large drawings made by himself upon the wood. They differ from the style of the
earlier masters, and frequently have a confused blotted look in the lines, which pro-
duce deep shadows ; they possess, however, all that boldness and vigour of treatment
for which the great Flemish painter was so deservedly celebrated ; but the engraviDg
is coarse and mechanical. Rubens appears to have felt this, and sometimes a tinted
block is added over all, with high lights cut upon it, to give softness and brightness
to the whole ; an idea he may have adopted from the engravers of Italy who suc-
ceeded Ugo da Carpi (among whom may be honourably mentioned Andreas Andreani,
of Mantua, born 1540, died 1620), or from the designs of Lalleman engraved by Bu-
sinck, which were nearly contemporaneous in France.
Though " fallen from its high estate," the art never sank into complete decay,
either in England or upon the continent; there were always a few who followed the
profession, and aided the printer with such cuts and diagrams as he might require.
The family of the Jeghers practised in Antwerp until the end of the century; a clever
series of woodcuts illustrative of the service of the Mass was published at Ghent,
and executed by Kraaft in 1732. In France, the family of Le Sueur were employed
through three generations by booksellers ; the last, Nicholas, died in 1764; while
Papillon, the author of a Traits de la Gravure en BoU, had practised the art from the
commencement of the century until 1770, and had been patronised so extensively by
the booksellers of France and Holland that he counts his cuts by the thousand. In
England, E. Kirkhall executed cuts for books, and from 1722 to 1724 a series of 12
block- prints, in imitation of Ugo da Carpi's work already alluded to ; in this latter style
he produced a greater pupil in J. Jackson, who very successfully copied some of the
great works of Titian, Paul Veronese, and others, during the years 1738 to 1742 ; at this
time he resided in Venice, after a short sojourn in Paris, where he was occasionally
employed as a wood-engraver. Many cuts scattered through English books about
the same period bear the initials of F. H. for Francis Hoffman, whose name is en-
graved in fiill on a tail-pipce, representing cupids surrounding a lighted altar, to be
seen in the first edition of Gulliver'a Travels, 1726, vol. ii. p. 47. An engraver named
Lister executed some cuts of a much better character than usual about 1760, particularly
those in the Oxford Sausage; and in Sir John Hawkins's History of Music are some of
the largest and most ambitious cuts at that time attempted anywhere. They were
engraved by T. Hodgson. Three other persons named respectively, W. Pennock,
S. Watts, and H. Cole, occasionally devoted themselves to wood-engraving, which
seems to have been practised by such copper-plate engravers as devoted themselves
to *• general work " for the printing trade or the public, and who varied their labours
by occasionally engraving shop-bills or door-plates.
There is one great change in the cuts produced during this period, the result of a
different style of drawing made for the wood-engravers, and which discarded cross-
hatching and its consequent tedious labour, for a tinted or vrashed drawing which
could be cut into a series of lines by the tool, expressing the varied tints more simply
and readily. The art of ** lowering *' or scraping down to a lower level various parts
of a cut that should appear light, and so assist the press in its labours, was «lso prac-
tised, and the harder wood of the box tree used. Such was the state of the art when
a Northumbrian peasant boy was destined to appear, again draw universal attention
to the neglected profession, and found the modem school of wood engraving.
Thomas Bewick was the son of parents engaged in a colliery, who lived at Cherry-
bum twelve miles west of Newcastle-on-Tyne ; he was bom in 1763 and passed his
• In the old printing oflBce of Plantyn at Antwerp, !• still prescrred a large quantity of voodrntt, ori-
ginallj engraved for the boolis be issued at the end of the 16th century, particularly the embleina of
Alciatl and Sambaco.
t The number of impressions a woodcut will yield has never yet been esUbllshed. The elasticity of
wood gives it a great advantage over metal in press-printing; and while copper and steel wear out,
wood shows little sign of wear ; many thousands of impressions may be taken by a carefully moderate
printer without injuring a woodcut. As an instance with what impunity a bad printer may use a coarse
woodcut, may be mentioned the fact, that the ballad printers of the middle of the last century occaaloa-
ally used cuts that had been engraved in the reign of Charles L, and had headed popular ballads for
more than 100 yeart.
ENGRAVING. 147
early jesn helping his fkther's labour. His leisure hoars -were earnestly devoted to
the small amount of knowledge a village school could impart ; but as a strong love
for nature, and for its imitation, soon developed itself in the boy, his father determined
to apprentice him to an engraver of Newcastle, Mr. R. Bcilby, whose work was of that
" general " kind undertaken in a busy country town. There he occasionally engraved
initials on tea-spoons or names ou door plates, until, in the second year of his ap-
prenticeship, his master received an application from Dr. Hutton for wood-cut
diagrams, such as were then executed in London, to illustrate his treatise on
mensuration. Beilby knew that young Bewick had been making some attempts in
this style and he encouraged him to persevere; he did so, and Hutton's book was
published in 1770 with Bewickls cuts. The young engraver had many difficulties to
contend against, and had even to construct his own tools ; among the rest, a double-
pointed graver to enable him to cut both sides of a line at once, and so ensure its
equal thickness throughout In 1775, he executed a cut and sent it to the Society of
jljts, in London, who awarded him a medal ; and in the following year he visited
London, and was employed by Hodgson, whom we have already noted as the engraver
of the cuts in Hawkins's History of Music; as well as by H. Cole. There need be
Uttle doubt that this visit to the London wood- engravers was useful to Bewick, for he
must have become by that means acquainted with the usual mode of practising the art,
the proper kinds of tools used, and the various things which make the mechanical part of
the profession ; but he had fortunately formed a style of his own, so very original, and
based so finnly on the study of nature, that wood-engraving in his hands became an art
presenting many novel and attractive features never visible before. The wood-engravers
ftom the days of Durer, or from the first invention of the art, depended slavishly on the
drawings made upon the wood, and did little more than cut away the interstices; but
Bewick cut out of the wood a vast deal of that which no draughtsman could so draw ;
for with the aid of a slightly tinted drawing, he would cut Uie foliage of trees, the
plumage of birds, the texture of animals, or small figures and birds, by the graving
tool alone. His dextrous hand was guided by a perfect knowledge of nature, and
every line be cut expressed drawing ; in this was his great distinction over all other
wood engravers ; he cut his pictures out of the wood, the others cut the wood out of
the pictures.
Bewick disliked London, and speedily returned to his native place. His first work
was an illustrated edition of Qay*8 Fables, published in 1779 by T. Saint, a printer of
Newcastle, much engaged in the publication of children's books, and such as the
travelling chapmen carried in their packs for the edification of the villagers. These
cots bear the earliest traces of that accurate delineation of nature, and minute truth-
fulness of expression, which ultimately gave his works universal renown. The wild
plants and grasses, however minute they are cut, can always be distinguished by the
naturalist ; the proper foliage of every tree is truthfully cut by his graver ; the birds
and insects, however minute, are perfect in drawing ; and the general effect of his
wood-cuts artistically powerful As he fnll^ felt the value of leaving the wood itself
to express solid shadow, he had not the timidity which imagines labour to be neces-
sary to success. The little cut of the Fox and the Bramble in this volume is a good
illustration of Bewick's mode. Every leaf of the bramble is cut out, white upon
black, with the most truthful power of drawing ; the spines on the stem of the bramble
are visible to the eye ; the fern beside it is similarly expressed by cutting the form
of its foliage with the most perfect freedom upon the solid block of wood. Each
bush has its distinctive leaf. The dogs in tbe distance arc similarly cut out by the
graver on a tinted ground ; and the few lines which cover the body of the fox
entangled in the bramble, express its texture with a spirit which no mere cutting of a
drawing placed on wood by a professional draughtsman could ever give. Bewick's
cuts are sometimes termed coarse^ but no elaboration of labour will elevate the costliest
woodcut above these works, for which Bewick obtained but nine shillings each;
unless drawing can be expressed by the engraver as perfectly as Bewick could
express it.
Assisted by his brother John, the Newcastle engraver issued a series of works
devoted to natural history ; the best being the History of British Birds, Here
Bewick's knowledge of nature, and power of expression by means of his graver
shone forth conspicuously. His books became equally celebrated for tbe hum6rou8
tail-pieces he occasionally introduced redolent of whim and original genius. He labcmred
stead&stly at his art to a good old age. His brother John \tefi Newcastle to reside in
I>ondon, where he was much employed, but a pulmonary complaint killed him at the
early age of thirty-five. He died in 1795. Thomas Bewick lived to the advanced
age of seventy-five. He died in 1828, having worked upon a large woodcut only
a few days before his death.
The pupils educated by Bewick were few. The best were Charlton Nesbit, Luke
L 8
148 ENGRAVING.
Clennell, William Hanrey, and John Jackson. Nesbit settled in London, and
extensively employed during a long life. Clennell after a while, devoted himself to
pa'mting. Harvey turned bis attention to drawing on vood, and bis designa for book
illustration may be numbered by the thousand ; his best are in Lane's edition of the
Arabian NiyhU Entertainments. Jackson was greatly employed by the publiaher of
the latter work, Mr. Charles Knight, particularly on the best cuts in the once-fiuned
Penny Magazine,
At the early part of the present century, Mr. Robert Branston founded a London
school of wood-engravers, of which he was the head. His style was peculiar, imlike
Bewick's, though like him he was self-taught His cuts have more refinement, bat
less knowledge of nature ; his best pupil was John Thompson, who combines in his
best cuts, the refined knowledge of light and shade, with much of Bewick's power of
expressing drawing. Samuel Williams was one of the few modem engravers, who
made his own drawings upon the wood, and he produced very brilliant effects by
frequently leaving the wood in solid masses of bkick. Drawings for wood engnven
were at this time chiefly supplied by artists who devoted themselves to that particular
branch of the art ; and knew how to design their compositions so that they should
best display th( peculiarities of wood-eugraved e£ESects. Thurston, Craig, and Harvey
were the principal artists so engaged.
A large number of wood-engravers, the pupils of the Newcastle and London aidiert^
helped to supply the booksellers at home and abroad for a considerable number of
years. It was the custom, some twenty years ago, for the foreign booksellers, parti-
cularly in Paris, to send the blocks across the channel to English engravers to execute ;
this led ultimately to several settling on the continent, particularly in France and
Germany. The French publishers always sent the wood block with the drawing
carefully executed on its surface, by a native artist These drawings were always
elaborately executed in pencil, greatly resembling etchings ; little was consequently
left for the engraver to do, but follow the lines and cut away the spaces ; patience
hence became the chief virtue of the wood engraver ; and it was ultimately found
that its exercise produced so certain an effect, that apprentices knowing nothing of
art might aid in thus working out good engravings ; and the old style of tinted draw-
ing on wood was discarded for this *'fiic-simile" work ; the best draughtsmen among
the French and German artists having willingly furnished these drawings, English
artists of a higher grade were induced to draw on wood, but they occasionally iaikd
from not clearly understanding the peculiar effects their work should produce, and
the characteristics of the art. Generally speaking, wood engravers prefer cutting
ft'om the drawings of professional draughtsmen on wood ; who generally execute their
work with such elaborate precision, that the engraver has nothing more to do than
follow their lines ; this, however, has made mere mechanism of much modem wood-
engraving ; and many expensive cuts exhibiting pencilling in crossed and re-crossed
lines, occupying wearisome labour, and costing many ill-bestowed sovereigns, caa
only be classed with such '* art '* as is devoted to engraving the Lord's Prayer in the
compass of a silver penny ; and merely produces the same general effect that Bewick
would have obtained in a few bold lines.
The great difference between ancient and modern wood engraving consists in this
very boldness ; and the practice of the art was essentially different in the sixteenth and
eighteenth centuries. The old wood engravers cut on large blocks of soft womi,
such as pear-tree, the way of the grain ; the modems, on small blocks of the hardest
wood they can obtain — the turkey box, and across the grain. The old engravers
cut the work downwards with small knives or gouges ; the moderns use gravers of
various widths to cut out the spaces between fine lines, and broader chisels or gouges
to clear away the broad spaces of white. Wood engraving is the exact opposite to
copper-plate engraving in the mode by which the lines of engraving are produced.
The copper-plate engraver produces his lines by cutting into the metal at once, the
wood engraver produces his lines in relief cut out of the block of wood ; every line
he engraves has to be cut by a double operation, by slicing away the wood on each
side of it ; for though it is recorded that Ikwick invented a double cutting fork-shaped
graver to cut away both sides of a line at once, no such tool has ever since been
used in the profession.
In order to luake the whole process of wood engraving clear to the reader,
we will now simply describe the production of a wood cut from the time it leaves
the timber-merchant, until it is fit for the hands of the printer. The log of box is cut
into transverse slices, I of an inch in depth, in order that the face of the cut may be on
a level with the surface of the printer's type, a d receive the same aniount of
pressure ; the block is then allowed to remain some time to dry, and Uie longer it is
allowed to do so the better, as it prevents accidents by warping and splitting, which
sometimes happen after the cut is executed if the wood is too green. The slice is
ultimately trinuned into a square block, and if the cut be large, it is made in various
ENVELOPES. 149
pieoes strongly clamped and screwed together ; and this enables engravers to get
large cuts done in an incredibly short space of time, by patting the various pieces
into different engravers' hands, and then screwing the whole together. The upper
surface of the wood is carefully prepared so that no inequalities may appear upon
tt» and it is then consigned to ihe draughtsman to receive the drawing. He covers
the surface with a light coat of flake white mixed with weak gum- water, and the
thinner this coat the better for the engraver. The French draughtsmen use an
abundance of flake white, but this is liable to make the drawing rub out under the
engraver's hands, or deceive him as to the depth of the line he is cutting in the wood.
The old drawings of the era of Durer seem to have been carefully drawn with pen
and ink on the wood ; but the modem drawing being very finely drawn with the
pencil or silver point is obliterated easily, and there is no mode of *' setting '* or
securing it To obviate this danger the wood-engraver covers the block with paper,
and tears out a small piece the size of a shilling to work through, occasionally re-
moving the paper to study the general effect, in damp and wintry weather he some-
times wears a shade over the mouth to hinder the breath from settling on the block.
It is now his business to produce in relief the whole of the drawing ; with a great
variety of tools he cuts away the spaces, however minute, between each of the pencil
lines ; and should there be tints washed on the drawing to represent sky and water,
he cuts such parts of the block into a series of close lines, which will, as near as he
can judge, print the same gradation of tint. Should he find he has not done so com-
pletely, be can re-enter each line with a broader tool, cutting away a small shaving,
thus reducing their width and consequently their colour. Should he make some fatal
error that cannot be otherwise rectified, he can cut out the part in the wood, and
wedge a plug of fresh wood in the place, when that part of the block can be re-
engraved. An error of this sort in a wood-cut is a very troublesome thing ; in copper
engraving it is scarcely any trouble ; a blow with a hammer on the back will obliterate
the error on the fiice, and produce a new surface ; but in wood, the surface is cut
entirely away except where the lines occur, and it is necessary to cut it deep enough
not to touch the paper as it is squeezed through the press upon the lines in printing.
To aid the general effect of a cut, it is sometimes usual to lower the surface of the
block before the engraving is executed in such parts as should appear light and delicate ;
they thus receive a mere touch of the paper in the press, the darker parts receiving
the whole pressure and coming out with double brilliancy. When careful printing
is bestowed on euts, it is sometimes usual to ensure this good effect, by laying thin
pieces of card or paper upon the tympan, of the shape needed to secure pressure on
dark parts only.
Wood engraving, as a most useful adjunct to the author, must always command a
certain amount of patronage. In works like the present, the author is greatly aided
by a diagram, which can more clearly explain his meaning than a page of letter-
press ; and it can be set up and printed with the type, a mode which no other style
of art can rival in simplicity and cheapness. The taste for elaborately executed
wood engravings may again decrease, as we find it did for nearly two centuries ; but
it was never a lost art, and never will be, owing to the practical advantages we speak
of, unless it be superseded by some simpler mode of doing the same thing hitherto
undiscovered. The number of persons who practise wood engraving in London
alone, at present is more than 200, and when we consider the quantity done in the
great cities of the continent, and the large amount of book illustration in constant
demand ; the creative power of one single genius — Thomas Bewick — shines forth
in greater vigour than ever. — F. W. F.
ENTRESOL. A floor between other floors ; a low set of apartments placed above
the first floor. The Quadrant, Regent Street, has a good example of the entresol.
In Italy the term Mazzanino, or little middle floor, is used to indicate the same
arrangement*
ENVELOPES. The manufacture of envelopes has so largely increased, that the
old method of folding them by means of a **bone/oldinQ stick,** although a good workman
could thus produce 3000 a day, was not capable of meeting the demand ; hence the
attention of several was turned to the construction of machines for folding them.
Amongst the most successful are the following.
Envelope folding, — In the envelope folding machine of Messrs. De la Rue & Co., each
piece of paper, previously cut by a fly press into the proper form for making an envelope
(and baring the emblematical stamp or wafer upon it), is laid by the attendant on a square
or rectangular metal frame or box, formed with a short projecting piece at each corner,
to serves as guides to the paper, and furnished with a movable bottom, which rests on
helical springs. A presser at the end of a curved compound arm (which moves in a
vertical plane, then descends, and presses the paper down into the box, — - the bottom
thereof yieldmg to the pressure ; and thereby the four ends or flaps of the piece of paper
L 3
150 EQUIVALENTS, CHEMICAL.
are caused to fly ap ; the presser may be said to consist of a rectangular metal frame, tbe
ends of which are attached to the outer part of the carved arm, and the sides thereof to
the inner portion of the arm ; so that the ends and sides of the presser can move inde-
pendently of each other. The ends of the presser then rise, leaving the two sides of it still
holding down the paper ; two little lappet pieces next fold over the two side flaps of tlie
envelope ; and immediately a horizontal arm advances, carrying a V-shaped pieceebarged
with adhesive matter or cement (from a saturated endless band), and applies the eme
to the two flaps. A third lappet presses down the third flap of the envelope upon the
two cemented flaps, and thereby causes it to adhere thereto ; and then a pressing-piece,
of the same size as the finished envelope, folds over the last flap and presses the whole
flat. The final operation is to remove the envelope, and this is effected by a pair d
metal fingers, with indiarubber ends, which descend upon the envelope, and, momt:
sideways, draw the envelope off the bottom of the box (the pressing piece having mored
away and the bottom of the box risen to the level of the platform of the machine) on to
a slowly moving endless band, which gradually carries the finished envelopei away. A
fresh piece of paper is laid upon the box or frame, and the above operations are repeated.
This machine makes at the rate of 2700 envelopes per hour.
Another machine for the same object, was invented by Mr. A. Remond, of Binniag-
ham, and is that employed by Messrs. Dickinson & Co. The distingaishing feature
of this arrangement is the employment of atmospheric pressure to feed in the paper
which is to form the envelope, and to deflect the flaps of the envelope into iodiiKd
positions, to facilitate the action of a pinnger, which descends to complete the folding.
The pieces of paper, cut to the proper form, are laid on a platform, which is furnished
with a pin at each corner, to enter the notches in the pieces of paper, and retain tieo
in their proper position, and such platform is caused alternately to rise and bring the
upper piece of paper in contact with the instrument that feeds the folding part of the
machine, and then to descend until a fresh piece is to be removed. The feeding in-
strument consists of a horizontal hollow arm, with two holes in the under side, and
having a reciprocating movement. When it moves over the upper piece of paper
on the platform, a partial vacuum is produced within it, by a suitable exhausting ap*
paratus, and the paper is thereby caused to adhere to it at the holes in its nnder sur-
face by the pressure of the atmosphere. The instrument carries the paper o«r »
rectangular recess or box ; and then, the vacnum within it being destroyed, it depositi
the paper between four pins, fixed at the angles of the box, and returns for another piece
of paper. As the paper lies on the top of the box, the flap which will be nndennott
in the finished envelope, is pressed by a small bar or presser on to the upper edge «
two angular feeders, communicating with a reservoir of cement or adhesive matter, and
thereby becomes coated with cement ; and at the same time, the outermost or seal flap
may be stamped with any required device, by dies, on the other side of the machine.
A rectangular fhime or plunger now descendis and carries the paper down into the box;
the plunger rises, leaving the flaps of the envelope upright ; streams of air, issuing from
a slot in each side of the box, then cause the flaps to incline inwards : and theibldm^
is completed by the plunger again descending ; the interior and under surfiwe of suca
plunger being formed with projecting parts, suitable for causing the several ^P* *J
fold in proper superposition. The bottom of the box (which is hinged) opens, and
discharges the envelope down a shoot on to a table below ; the feeding instrument
then brings forward another piece of paper ; and a repetition of the above movements
takes place.
EPSOM SALTS. A sulphate of magnesia, consisting of magnesia 16-26, snlphane
acid 32-52, water 51 '22. It derives its name fh)m a mineral spring contaimng tne
salt at Epsom. It is largely manufactured. See DoLoifiTE. ^^
EQUISETUM. Horsetails. A family and genus of acotyledonons plants, wc
Dutch Rush.
EQUIVALENTS. CHEMICAL. By this term is understood the proportioni »
which substances combine with each other to form definite compounds. These ^
portions are referred to the common standard, hydrogen, which is taken as umtf-
The limits of this work preclude the possibility of entering into the history »
the steps by which the doctrine of equivalents was gradually developed ; ^"* '^ ^
proper that we should indicate some of the methods by which the equivalents of ele-
ments and compounds are ascertained and demonstrated to be correct Bnt befo^
proceeding it is necessary to define the term equivalent This is not easy to <»,
because tibe theoretical ideas of all chemists are not the same. Suppose, for y
ample, the constitution of water were to be taken as the starting point On ^'^^f^^^j^J
it to the action of the pile, it is immediately observed that the ratio of the ^
gases evolved is as 1 to 2. One chemist will at once assume that water is a si^iP
binary compound of one equivalent of each of its constituents. But this involves
assumption that the gaseous volume of the equivalent of hydrogen is twice that
EQUIVALENTS, CHEMICAL. 151
oxygen. The other chemist assDining that one yolnme of a gas represents an eqaiva-
lent, considers water to be a ternary compoond having the formula H^O. It is plain
that the atom of hydrogen will have only half the value on the second hypothesis that
it will on the first, or, what comes to the same thing, the atom of oxygen will be
twice as great If, with some chemists, we consider the volumes of the gases to repre-
sent atoms or eqairalents, then, water consisting of two volumes of hydrogen and one
volume of oxygen, and as by weight water contains 8 parts of oxygen to 1 part of
hydrogen, it is plidn that 8 parts of oxygen by weight will represent one equivalent,
and 1 part by weight of hydrogen will represent 2 equivalents. Consequently 1
equivalent of hydrogen will weigh '5. But to avoid fractional numbers it will (on these
a^umption8)be more convenient to write the equivalent of hydrogen -i 1, and oxygen
1 6. In this country it is usual to consider the atom of hydrogen as occupying twice the
space in the gaseous state of that of oxygen. The atomic weights being, therefore,
oxygen 8 and hydrogen 1.
We have said that it is b^ no means easy to define an equivalent The difficulty
arises not merely from the different aspects under which theoretical chemists regard
the elements and their compounds, but also from the practical difficulties attending
the determination of the true constitution of some substances. Thus the equivalent
of bismuth is assumed by some to be 71 and by others 213 ; the oxide in the one
case becomes BiO, in the other BiO\ The first equivalent being only one-third as
great as the second. But, it is to be observed, the variations in the theoretical views
of chemists are of no consequence, so long as we clearly comprehend the nature of
those variations. The r^ative values or proportions are the same in all cases. It is,
in fact, somewhat the same as if one class regarded the avoirdupois pound as made up
of sixteen ounces, each ounce weighing 437 '5 grains, and the other considered it as
consisting of eight ounces, each ounce containing 875 '0 grains.
In order to clearly understand the nature of the equivalents as received in this
country, it is necessary to remember that there are three relations of volume amongst
gases, namely, one, two, and four volumes. The first relation applies solely to ele-
mentary gases, file two others apply to elements and compounds. [It is true that
the vapour densities of pentachloride of phosphorus, chloride of ammonium, and,
perhaps, one or two other substances, appear to diflPer from this rule, but it is probable
that like sulphur, the vapourdensities require to be determined under special conditions
of temperature or pressure.] In the table of equivalents the density of the vapours
of those substances which are capable of assuming the gaseous states are so placed
that the number obtained by experiment may be compared with that deduced from
theoretical considerations. In the following table the vapour volumes or combining
measures of some of the more important elements are given. We shall see presently
the practical value of the information contained in it
Combining
Comblnlug
Elpmcnt.
Measure.
Blene&L
Measure.
Hydrogen
-
-
-
two volumes.
Oxygen -
-
-
-
one volume.
Chlorine -
-
m
-
do.
Salphur -
-
-
-
do.
Bromine -
.
.
-
do.
Selenium -
-
-
•
do.
Iodine
-
.
^
do.
Phosphorus
*
-
.
da
Fluorine (fiypotheUcal)
.
do.
Arsenic -
-
-
-
do.
Nitrogen *
«
-
-
do.
Carbon
-
-
-
do.
It must be remembered that all volatile compounds possess four volume formulse,
except a few, which in this country are always written as if possessing a condensation
to two volumes ; such are carbonic acid, carbonic oxide, sulphurous acid, &c With
the above information it will be easy for any person to calculate the density of any
vapour or gas by the aid of the following directions.
To obtain the density of any vapour or gas hamng a condensation to four volumes,
such as most organic or inorganic compounds, — Multiply half the density of hydrogen
by the atomic weight of the vapour or gas. Example : — Find the density of the
vapour of hydrobromic acid. The atomic weight of bydrobromic acid is 81. The
density of hydrogen is 0 0692, half of which is 0 0346. Then 00346 x 81 « 2*8026.
Experiment gave 2*73.
To obtain the density of any vapour or gas having a condensation to two vohanes,
— Multiply the density of hydrogen by the atomic weight of the gas or vapour.
Example : — Find the density of chlorine gas. The atomic weight of chlorine being
35*d, and the density of hydrogen 0 -0692, we have by the rule, 0*0692 x 35 '5 » 2 4566.
The density by experiment is 2*44.
To obtain the density of any vapour , or gas^ having a condensation to one «o/t<me.— >
Multiply twice the density of hydrogen by the atomic weight of the gas or vapour.
Example : — Find the density of Sie vapour of oxygen. The atomic weight of
L 4
152 EQUIVALENTS, CHEMICAL.
oxygen being 8, and twice the density of hydrogen being 0*1384, we hATe
0*1384 X 8 e 1*1072. Experiment has yielded I -1056.
The above methods of calculating the densities of vapours and gases are those always
employed by the writer of this article, and will be found incomparably shorter' and
more convenient than any other.
It is perfectly plain that, by a simple inversion of the above rol^ it is eqnaJly easy
from the known density of a gas or vapour to calculate its atomic weight. Never-
theless, for the sake of those who are unaccustomed to calculations of this kind, we
append the following rules.
To calculate the atomic weight o/ any gas or vapour having a condentation to fonr
volumes. — Divide the density of the gas by half the density of hydrogen. Ezavple :
— Find the atomic weight of hydrobromic acid gas, the density of which is 2-8026 ;
2*8026 ^, ^^
0^0346-®^-«^^-
To calculate the atomic weight of any gas or vapour having a condensatiom to two vo-
lumes, — Divide the density of the gas by the density of hydrogen.
To calculate the atomic weight of any gas or vapour having a condensation to cne vo-
lume.— Divide the density of the gas by twice the density of hydrogen.
It is plain then that if we are in possession of the atomic weight and vapour volume of
any substance, it is easy to determine the density of its vapour or gas. Alaoi, that
having the density of the vapour and the vapour volume, it is easy to calculate the
atomic weight If we consider for an instant what is meant by the term density of a
vapour or gas, it will appear equally easy to find, from the density of the gas, the
weight of 100 cubic inches at the standard temperature and pressure. By the density
of a gas is meant the number expressing how much it is heavier or lighter, balk for
bulk, than air. If, therefore, we multiply the density of a gas by the wei^t of 100
cubic inches of air, at the standard temperature and pressure (» 30*00 grainsX ve
immediately find the number required. Example : — The density of hydrogen is
0*0692 and 0*0692 x 30 « 2*0760, or the weight of 100 cubic inches of hydrogeo, at a
temperature of 60^ Fahr., and 30 inches of the barometer.
From what has been said, it is evident that no difficulty exists in determining the
equivalents of bodies which can be obtained in a gaseous state. Where the equi-
valent of a fixed body is to be ascertained, or where it is desired to proceed in a
different manner, the method employed must depend upon the nature of the substance.
We shall consider three of the most simple and general cases, namely, an acid, an
alkali, and a neutral body.
1. Mode of determining the equivalent of an acid. — For this purpose it is neces-
sary to analyse a salt, the constitution of which is known. If the base or metallic
oxide in the salt is one of which the atomic weight is well established, it is very easy
to determine the combining proportion of the aoid. We say, as the peroenta^ of
oxide is to the percentage of acid, so is the atomic weight of the oxide to the atomic
weight of the acid. Example : — Butyrate of silver has the following composition :-*
Oxide of silver .------ 59*487
Butjric acid -------- 40*513
We therefore say : —
100-000
59-487 : 40-513 :: 116 : 79-000
Percentage of oxide Percentage of acid. Equivalent of oxide Equivaient of the
ofailver. of silver. add.
It must be remembered that the atomic weight so obtained is that of the anhydrous
acid, so that one equivalent of water must be added to find the atomic weight of the
acid in its ordinary condition. If the equivalent desired be that of a hydrogen acid,
the method of proceeding must be slightly modified, but the details need not be given
as they are self-evident
2. Mode of determining the equivalent of an alkali. — Several methods present them-
selves, each possessing certain advantages. Most alkalies, organic and inorganic,
form salts well adapted for enabling their atomic weight to be ascertained by analysis.
We shall select as an example ammonia, and the salt employed to settle the atomic
weight will be the sulphate, which contains : —
Oxide of ammonium - - - - - - 39*40
Sulphuric acid . - . . ... 60*60
100*00
In the same way that an oxide of known composition is the datum employed to
EQUIVALENTS, CHEMICAL.
153
deteimine the equiyalent of an acid, so, on the other hand, an add, the formula of
which is irell established, serves to enable the formula of an alkali to be deduced. We
therefore say : —
60*60 : 39*40 :: 40*00 : 2600
V V ■ '
PerceoUge of acid. PercenUge of alkali.
Equivalent of the
add.
Equivalent of the
alkalL
Most alkalies, especially those derived from the organic kingdom, form well defined
and easily crystallisable compounds with some of the metallic chlorides, especially
those of gold, platinum, and palladium. These salts are well adapted for enabling
atomic weights to be fixed.
3. Mode of deiermining the equivalent of a neutral substance. — Neutral bodies are
formed upon so many models or types that no general method can be given for the
required purpose. If volatile at moderate temperatures, the density of the vapour can
be ascertained, and this is generally sufficient Salts have their equivalents found
by determining the percentage composition, and proceeding as in examples 1 and 2.
"The equivalent of a metal is found by forming a compound with some substance, the
atomic weight of which is well known, such as oxygen or sulphur. The compound is
then carefully analysed. Exakple : — It has been found that 100 parts of oxide of
copper contain
Copper --------- 80*00
Oxygen- ------- -20*00
We therefore say:— .
20*00
8000
8*00
100*00
32*00
Percentage of Percentage of Equivalent of Equivalent of
oxygen. copper. oxygen. copper.
A precisely analogous mode of proceeding may be adopted with chlorides, iodides, &e.
A careful study of the numbers in the following tables will enable us to observe
nnmerous and highly iq^resting relations subsisting between them. It has been
shown by M. Dumas that certain families or groups of elements fall into natural triads,
owing to the relations between their atomic weights. With bodies of this kind, it is
found that, if the sums of the atomic weights of the extremes of the series be divided
by two, we obtain the atomic weight of the middle body ; thus : —
Chlorine
Iodine
I.
35-5
127*0
H.
Sulphur 16*00
Tellurium 64*00
Lithium
Potassium
162*5
«81*25
80*00
s 40*00
in.
7*00
3900
46*00
« 23*00
2 2 2
The triads here are i. chlorine, bromine, and iodine; n. sulphur, selenium, and
tellurium ; in. lithium, sodium, and potassium. Space will not allow of the subject
being developed at greater length in this work. The student, interested in this branch
of chemistry, will find much information in the papers of Dr. Odling, recently pub-
lished in the Journal of the Chemical Society.
Table of the Equivalents^ ^c, of the Non-metaUic Elements.
Name.
Bromine -
Carbon
Chlorine -
Fluorine -
Hydrogen -
Iodine
Nitrogen -
Oxygen
Phosphorus
Selenium -
Sulphur
Symbol.
Equivalent Density as Var
ll»l.
pour or Gas.
Br
C
CI
Fl
H
I
N
O
P
Se
S
80*00
600
35*50
19*00
100
12700
14*00
8*00
3200
40-00
1600
5*4110
0*8290
2*4530
1-3270
0*0692
8-7827
0 9713
11056
4*2840
7*6960
2*2140
[Note. — The densities of the vapours of carbon, selenium, and fluorine are
hypotheticaL That of sulphur is usually represented by a number three times as
154
EREMACAUSIS.
great as the above, bat this is owing to the experiment not haying been performed at
a sufficiently high temperature.]
Table of the Equivalents of the Metallic Elements.
Nmme.
Aluminium
Antimony
Arsenic
Barium
Bismuth
Boron
Cadmium -
Calcium
Cerium
Chromium
Cobalt
Copper
Didymium -
Erbium
Glucinum •
Gold -
Ilraenium -
Iridium
Iron -
Lanthanium
Lead -
Lithium
Magnesium
Manganese
Mercury -
Molybdenum
Nickel
Niobium -
Osmium
Palladium -
Platinum -
Potassium -
Rhodium -
Ruthenium
Silicon
Silver
Sodium
Strontium -
Tantalum -
Tellurium -
Terbium -
Thorium -
Tin -
Titanium -
Tungsten -
Uranium -
Vanadium -
Yttrium
Zinc -
Zirconium •
Symbol.
EqiilTalent
SfKcifie
GraTity.
AI
I.V67
2*56
Sb
12900
.6-70
As
7500
5-67
Ba
68-50
4-70
Bi
21300
9-80
B
11 00
263
Cd
6600
863
Ca
20-00
1-58
Ce
4600
Cr
26-27
5-90
Co
29-50
8-53
Cu
3200
8*72
D
48-00
E
G
6-97
Au
98-^3
19-4 to 19-6
li
Ir
98-56
18-63
Fe
28-00
7-84
U
Pb
104 00
11-30
L
7-00
0-5936
Mg .
12-00
1-75
Mn •
26-00
800
Hg
100-00
13-50
M
48-00
8-60
Ni
29-50
8-63
Nb
Os
99-41
10-0
Pd
53-24
11-50
Pt
90-00
21-50
K
39-00
0-865
Ro
52-16
11-20
Ra
52-11
8-60
Si
2100
Ag
108 OO
10-43
Na
23-00
0-97
Sr
44-00
2-54
Ta
Te
64-08
6-30
Tb
Th
59-60
Sn
5900
7-29
Ti
24-12
5-28
W
92-00
17-2 to 17-6
U
6000
10*15
V
68-46
Y
Zn
32-52
6-91
Zr
33-58
It will be seen, from the above table, that a very considerable number of the equiva-
lents are entire multiples of that of hydrogen. M. Dumas and others have, however,
shown by elaborate and conclusive experiments, that the doctrine of the equivalents
of all elements being multiples of that of hydrogen is not a law of nature, as, in
addition to chlorine, there are several undoubted exceptions. — C. G. W.
EREMACAUSIS, — 9/010 combustion. This term has been applied to that constant
combination of oxygen with carbon and hydrogen, to form carbonic acid and water,
which is anceasingly going on in nature, as in the decay of timber, or the '* heating "
ETCHING VARNISH. • 155
of hay or grain pat toother in a moist state. Perfect dryness, and a temperature
below freezing, stops this eremacausis, or slow combustion.
ERYTHRIC ACID. Colorific principle of Angola and Madagascar Orcbilla
-weeds (See Orchuxa.) By macerating the lichen m milk of lime, Stenhoose ob-
tained 12 per cent, of crude erythric acid. It yields red coloured compounds with
ammonia, and also in its reaction with hypochlorite of lime. See Lichen.
ERMINE. See Fur.
ERRATIC BLOCKS. Rounded and weather-worn fragments of the harder
rocks, which are found very widely scattered, at great distances trota the places from
-which they are supposed to have been deriyed. They are generally supposed to have
been removed by the transporting power of icebergs and fields of ice.
ESPARTO. A species of rush — the Stipa tenacwtima — found in the southern
provinces of Spain. It is used for making cordage, shoes, matting, baskets, nets,
mattresses, sacks, &c. Cables made of esparto are said to be excellent *, being light,
they float on the surface of the water, and are not therefore so liable as hempen cubles
to be cut or injured by a foul bottom. — M^CuUocfu
ESSENCE OF SPRUCE is prepared by boiling the young tops of the Abies nigra, or
black spruce, in water, and concentrating the decoction by evaporation in a water bath.
ESSENCES. See Psbfumebt.
ESSENTIAL OILS. See Oils, fixed and essential, and Otto.
ESSENCE D'ORIENT, the name of a pearly looking matter procured from the
blay or bleak, a fish of the genus cyprinus. This substance, which is found princi-
pally at Uie base of the scales, is used in the manufacture of artificial pearls. A large
quantity of the scales being scraped into water in a tub, are there rubbed between the
hands to separate the shining stuff, which subsides on repose. The first water being
decanted, more is added with agitation till the essence is thoroughly washed from aU
impurities, when the whole is thrown upon a sieve ; the substance passes through, but
the scales are retained. The water being decanted ofi^ the essence is procured in a
▼iscid state, of a bluish-white colour, and a pearly aspect. The intestines of the
same fish are also covered with this beautiful glistening matter. Seyeral other fish
yield it, but in smaller proportion. When well prepared, it presents exactly the ap-
pearance and reflections of the real pearl, or the finest mother of pearl ; properties
which are probably owing to the interposition of some portions of this same substance
between the laminsB of these shelly concretions. Its chemical nature has not been
investigated ; it putrefies readily when kept moist, an accident which may however
be counteracted by water of ammonia. See Pbahls.
ETCHING VARNISH. {Aetzgrynd-DeckfimiM, Germ.) Though the practice
of this elegant art does not come within the scope of our Dictionary, the preparation of
the Tarnishes, and of the biting menstrua which it employs, legitimately belongs to it.
The varnish of Mr. Lawrence, an English artist resident in Paris, is made as
follows : Take of virgin wax and asphaltum, each two ounces, of black pitch and
burgundy- pitch, each half an ounce. Melt the wax and pitch in a new earthenware
glazed pot, and add to them, by degrees, the asphaltum, finely powden'd. Let the
whole boil till such time as that, taking a drop upon a plate, it will break when it is
cold, on bending it double two or three times betwixt the fingers. The varnish,
being then enough boiled, must be taken off the fire, and after it cools a little, must be
poured into warm water, that it may work the more easily with the hands, so as to be
formed into balls, which must be kneaded, and put into a piece of taffety for use.
Care must be taken, first, that the fire be not too violent, for fear of burning the in-
gredienta, a slight simmering being sufficient ; secondly, diat whilst the asphaltum is
putting in, and even after it is mixed with the ingredients, they should be stirred con-
tinually with the spatula ; and, thirdly, that the water into which this composition is
thrown should be nearly of the same degree of warmth with it, in order to prevent a
kind of cracking that happens when the water is too cold.
Preparation ^the hard varnish used by Caliot, commonly eaUed the Florence Var-
nish Take four ounces of fat oil very clear, and made of good linseed oil, like that
used by painters; heat it in a clean pot of glazed earthenware, and afterwards put to it
four ounces of mastick well powdered, and stir the mixture briskly till the whole be well
melted, then pass the mass through a piece of fine linen into a glass bottle with a long neck,
that can be stopped very securely; and keep it for the use that will be explained below.
Method of applying the soft varnish to the plate, and of blackening it — The plate
being well polished and burnished, as also cleansed from all greasiness by chalk or
Spanish white, fix a hand-vice on the edge of the plate where no work is intended to
be, to serve as a handle for managing it when warm ; then put it upon a chafing-dish,
in which there is a moderate fire, and cover the whole plate equally with a thin coat
of the varnish ; and whilst the plate is warm, and the varnish upon it in a fluid state,
beat every part of the varnish gently with a small ball or dauber made of cotton
156 ETHER.
tied up in taffety, which operation smooths and distribates the yarnish eqoall oTer
the plate. . .
When the plate is thus uniformly and thinly covered -with the varnish, it must he
blackened by apiece of flambeau, or of a large candle which affords a copioas smoke;
sometimes two or even four such candles are used together for the sake of despatch,
that the varnish may not grow cold, which if it does during the operation, the plate
must be heated again, that it may be in a melted state when that operation is performed;
but great care must be obtained not to burn it, which when it happens may be easily
perceived by the varnish appearing burnt and losing its gloss.
The menstruum used and recommended by Tnrrell, an eminent London artist, for
etching upon steel, was prepared as follows : —
Take Pyroligneous acid 4 parts by measure.
Alcohol 1 part, mix, and add
l^itric acid I part.
This mixed liquor is to be applied from I to 15 minutes, according to the depth
desired. The nitric acid was employed of the strength of 1-28— the double aquafortis
of the shops.
The eau forte or menstruum for copper, used by Callot, as also by Piranesi, with a
Blight modification, is prepared, with 8 parts of strong French vinegar,
4 parts of verdigris,
4 ditto sea salt,
4 ditto sal ammoniac,
* I ditto alum,
16 ditto water.
The solid substances are to be well ground, dissolved in the vinegar, and diluted
with the water ; the mixture is now to be boiled for a moment, and then set aside to
cool. This method is applied to the washed, dried, and varnished plate, after it has
suffered the ordinary action of aquafortis, in order to deepen and finish the delicate
touches. It is at present called the eau forte a passer,
ETHER, C*H*0. (Or, for four volumes of vapour, OH'K)'. For the nature of fowr^
vdume formtd<B^ see the articles Equivalents, Chemical, and Formoub.) S^
Sulphuric ether. Oxide ofethyle, Ethylic or Vinic etiier, &c. &c. By this term is known
the very volatile fluid produced by the action on alcohol of substances having a power-
ful affinity for water.
Preparation on small scale. — A capacious retort with a moderate sized tubulature is
connected with an efficient condensing arrangement Through the tubulature passes
a tube connected with a vessel full of spirit, sp. gr. 0'83. The tube must have a stop-
cock to regulate the flow. A mixture being made of five parts of alcohol of the density
given above, and nine parts of oil of vitriol, it is to be introduced into the retort, and
a lamp flame is to be so adjusted as to keep the whole gently boiling. As soon as the
ether begins to come over, the stopcock connected with the spirit reservoir is to be
turned sufficiently to keep the fluid in the retort at its original level.
Preparation on large scale. — The apparatus is to be arranged on the same principle,
but, for fear of fracture, may be constructed of cast iron, lined with sheet lead in the
part containing the mixture. The chief disadvantage of this arrangement is its
opacity, whereby it becomes impossible to see the contents of the retort, and there-
fore not BO easy to keep the liquid at its original level. In this case the quantity dis-
tilling over must be noted and the flow of spirit into the retort regulated accordingly.
The most convenient mode of proceeding is to have a large stone bottle with a tubu-
lature at the side near the bottom (like a water filter) to hold the spirit A tube passes
from the bottle to the retort It has at the end, near the retort or still, a bend downwards
leading into the tubulature. If a glass still be used it must for ss^fety be placed in a
sand bath. The distillate obtained, either on the large or small scale, is never pure
ether, but contains sulphurous and acetic acids, besides water and alcohoL To
remove these, the distillate is introduced, along with a little cream of lime, into a large
separating globe, such as that mentioned under Bromine. The whole is to be well
agitated, and the lime solution then run off by means of the stopcock. The purified
ether still contains alcohol and water, to remove which it should be rectified in a
vater bath. The fluid will then constitute the ether of commerce. If the second
distillation be pushed too far the ether will, if evaporated on the hand, leave an un-
pleasant after smell, characteristic of impure ether. If wished exceedingly pure, it
must be shaken up in the separating globe, with pure water. This will dissolve
the alcohol and leave the ether, contaminated only by a little water, which may be
removed by digestion with quicklime and redistillation at a very low temperature on
a hot water bath.
EUCALYPTUS. 157
Pare ether is a colourless mobile liquid, sp. gr. 0*71. It boils at 95° F. The
density g^ its vapour is 2*56 (calculated)! Gay-Lussac found it 2 '586.
The word ether, like that of alcohol, aldehyde, &c., is now used as a generic term
to express a body derived Arom an alcohol by the elimination of water. Many chemists
write the formula C^ilK), and call it oxide of ethyl in the same manner as they regard
alcohol as the hydrated oxide of the same radical. But there is no just reason for
departiog from the law we have laid down with reference to the formules of organic
compounds. (See Equivalents, Chemical.) We shall therefore write ether CU'^C.
This view has many advantages. We regard, with Gerhardt and Williamson, ether
and alcohol as derived from the type water. Alcohol is two atoms of water in which
one equlTalent of hydrogen is replaced by ethyle; ether is two atoms of water in
which both atoms of hydrogen are replaced by that radicaL But there are a large
class of compound ethers procurable by a variety of processes. These ethers were
long regarded as salts in which oxide of ethyle acted the part of a base. Thus, when
butyrate of soda was distilled with alcohol and sulphuric acid, the resulting product
was regarded as butyrate of oxide of ethyle The compound ethers are regarded as
two atoms of water in which one equivalent of hydrogen is replaced by the radical of
an alcohol, and the other by the radical of an acid. In addition to those there are
othen more closely resembling the simple ethers. They are founded also on the
water type, both atoms of hydrogen being replaced bv alcohol radicals, but by
different individuals. They are called mixed ethers. The following formulas show
the chemical constitution of all these yarieties placed for comparison in juxtaposition
with their type : —
Hj"^ CH'i"^ C'Hm" C'H'O'S*^
Water (3 eqs.) Common etber. Methylo-ethjrlic ethrr. Butjric ether.
In the above formula the first represents the type water. The second common ether,
the two equivalents of ethyle replacing the two of hydrogen. In the third, we have a
mixed ether, one of the equivalents of hydrogen being replaced by ethyle and the other
by methyle. The fourth illustration is that of a compound ether : one of the hydro-
gens is there replaced by ethyle, and the other by the oxidised radical of butyric acid.
Ether is largely used in medicine and chemistry. In small doses it acts as a power-
ful stimulant Inhaled in quantity it is an ansesthetic. It is a most invaluable solvent
in organic chemistry for resinous, £itty, and numerous other bodies. — C. G. W.
ETHER, ACETIC, is used to flavour silent com spirits in making imitation
brandy, it requires therefore some additional notice beyond the other ethers. It may
be prepared by mixing 20 parts of acetate of lead, 10 parts of alcohol, and ll| of
concentrated sulphuric acid ; or 16 of the anhydrous acetate, 5 of the acid, and 4} of
absolute alcohol; distilling the mixture in a glass retort into a very cold receiver,
aigitating along with weak potash lye the liquor which comes over, decanting the
supernatant ether, and rectifying it by re-distillation over magnesia and ground
charcoaL
Acetic ether is a colourless liquid of a fragrant smell and pungent taste, of spec.
grav. 0-866 at 45° F., boiling at 166° F., burning with a yellowish flame, and disen-
gaging fumes of acetic acid. It is soluble in 8 parts of water.
Acetic ether may be economically made with 3 parts of acetate of potash, 3 of very
strong alcohol, and 2 of the strongest sulphuric acid, distilled together. The first pro-
duct must be re-distilled along with one-fifth of its weight of sulphuric acid ; as much
ether will be obtained as there was alcohol employed.
ETHIOPS was the name given by the alchemists to certain black metallic prepara-
tions. Martial ethiops was the black oxide of iron ; mineral ethiops, the black sul-
phuret of mercury ; and ethiops per se, the black oxide of mercury.
ETHYLAMINE, C^H'N. An exceedingly volatile base, discovered by Wurtz.
It is produced in a great number of reactions. Several alkaloids existing in the
animal and vegetable kingdoms afford ethylamine on distillation with potash. Its
density at 476°, is 0*964. It boils at 66° F. It is regarded as ammonia in which
an equivalent of hydrogen is replaced by ethyle. — C. G. W.
ETIOLATION. Deprived of colour by being kept in the dark. Celery, sea-kale,
and some other plants are purposely blanched or etiolated by excluding the light,
this exclusion preventing the formation of chioropkyll, the green colouring matter of
leaves.
EUCALYPTUS. The gum tree of the New Hollanders. Mr. Backhouse (Com-
panion to (he Botanical Magazine) says, " We often find large cavities between the
annual concentric circles of the trunk filled with a most beautiful red or rich ver-
milion coloured liquid gum, which flows out as soon as the saw has afforded it an
openmg. The gum yielded by the Eucalyptus resinifera is considered by druggists
158 EVAPORATION.
as not in the least inferior to the kind which the pterocarpos or red saonden
wood of India prodaces.
EUDIOMETER, is the name of any apparatus suhservient to the chemical exami-
nation of the atmospheric ur. It means a measure ofpurityj but it is employed merelj
to determine the proportion of oxygen which it may contain. The explosive eudio-
meter, in which about two measures of hydrogen are introduced into a graduated glass
tube, containing five measures of atmospheric air, and an electric spark is pused
across the mixtare, is the best of all eudiometers ; and of these, the siphon form pro-
posed by Dr. Ure in a paper published by the Royal Society of Edinburgh in 1819 is
the most convenient.
EUGENIA. A genus of plants of the order Myrtacese, called after Prince Eagene
of Savoy.
The most remarkable species of this genus is the allspice, or pimento tree. See
Pimento.
EUKAIRITE. An ore of silver found in a copper mine in Sweden. According to
Berzelius it consists of,
Selenium ------- -26"
Silver 38*93
Copper ------.- 23-05
Earthy matter ----... 890
Carbonic acid, &c. - - ♦ - - - -3*12
EUPIONE. A fluid first discovered by Reichenbach in wood tar. All the
properties of eupione agree with the indifferent hydrocarbons found in Boghead
naphtha. (See Naphtha, Boghead.) Eupione is so indifferent to the action of
acids, that it may be repeatedly treated with concentrated oil of vitriol, or fuming
nitric acid, without any action taking place. Its density varies with the boiling
point, from 0*633 to 0-740. It is said to be contained among the products of the
distillation of rape oil. There is no doubt that these hydrocarbons will, eventoallf,
be of great value in the arts. — C. G. W.
EURITR A granulous compound of feldspar and quartz, with sometimes garnet
" It generally occurs as veins, or as local masses in other gpranites, and rarely, I be-
lieve, as veins traversing other rocks at a distance from granite. These, therefore
are probably veins of segregation, or of injection during consolidation, and not of sub-
sequent formation." — Jukes's Student''^ Manual of GeMogy.
EVAPORATION (Eng. and Fr. ; Abdampfen; Abdunsten, Germ.) is the process
by which any substance is converted into, and carried off, in vapour. Though ice,
camphor, and many other solids evaporate readily in dry air, we shall consider, at
present, merely the vaporisation of water by heat artificially applied.
The vapour of water is an elastic fluid, whose tension and density depend upon the
temperature of the water with which it is in contact Thus the vapour rising frcMn
water heated to 165° F. possesses an elastic force capable of supporting a colomn w
mercury 10*8 high ; and its density is such that 80 cubic feet of such vapoor codUid
one pound weight of water ; whereas S2 J cubic feet of steam of the density corre-
sponding to a temperature of 212° and a pressure of 30 inches of mercury, weigh one
pound. When the temperature of the water is given, the elasticity and specific grt^^J
of the vapour emitted by it, may be found.
Since the yapour rises from the water only in virtue of the elasticity due to itsgsscooi
nature, it is obvious that no more can be produced, unless what is already incnmbeQt
upon the liquid have its tension abated, or be withdrawn by some means. Suppose |^'
temperature of the water to be midway between freezing and boiling, viz. 122°ranr.,
as also that of the air in contact with it to be the same, but replete with moistnre. so
that its interstitial spaces are filled with vapour of corresponding elasticity audspecitic
gravity with that given off by the water, it is certain that no fresh formation of vsp^^
can take place in Uiese circumstances. But the moment a portion of vapour is sljowea
to escape, or is drawn off by condensation to another vessel, an equivalent portion oi
vapour will be immediately exhaled from the water. ,
The pressure of the air and of other vapours upon the surface of water in an open vessel,
does not preyent evaporation of the liquid ; it merely retards its progress. Expcn*°J®
shows that the space filled with an elastic fluid, as air or other gaseous body, is ^^^P^r^
of receiving as much aqueous vapour as if it were vacuous, only the repletion of *"■
space with the vapour proceeds more slowly in the former predicament than in tn
latter, but in both cases it arrives eventually at the same pitch. Dr. Dalton very
ingeniously proved, that the particles of aeriform bodies present no permanent o^^.
to the introduction of a gaseous atmosphere of another kind among them, but ^^^J^
obstruct its diffusion momentarily, as if by a species of friction. Uence, exhalation
atmospheric temperatures is promoted by the mechanical diffusion of the vapoQ^
EVAPORATION. 159
througli the air with Tentilating fans or chimney draughts ; though under hrisk ebul-
lition, the force of the steam readily overcomes that mechanical obstruction.
The quantities of water eTaporated under different temperatures in like times, are
proportional to the elasticities of the steam corresponding to these temperatures. A
Teasel of boiling water exposing a square foot of surface to the fire, eyaporates about
725 graiDS in the minute; the elasticity of the yaponr is. equiyalent to 30 inches of
merenry. To find the quantity that would he eTaporated from the same surface per
minute at a heat of 88^ F. : — At this temperature the steam incumbent upon water is
capable of supporting 1*28 inch of mercury ; whence the rule of proportion is 30 :
1*^8 :: 725 : 30*93 ; showing that about 31 grains of water would be eTaporated in
the minute. If the ur contains already some aqueous vapour, as it commonly does,
then the quantity of CTaporation will be proportional to the difference between the
elastic force of that Tapour, and what rises from the water.
Suppose the air to be in the hygrometric state denoted by 0-38 ut an inch of
mercury, then the aboTC formula will become 30 : 1-28 — 0*38 : : 720 ; 2 1 '41 ; show-
ing that not more than 21^ grains would be evaporated per minute under these
circnmstances.
The elastic tension of the atmospheric Tapour is readily ascertained by the old ex-
periment of Le Roi, which consists in filling a glass cylinder (a narrow tumbler for
example) with cold spring water, and noting its temperature at the instant it be-
comes so warm that dew ceases to be deposited upon it This temperature is that
which corresponds to the elastic tension of the atmospheric Tapour. See Vapouh,
Table ot
TV'heneTCT the elasticity of the Tapour, corresponding to the temperature of the
water, is greater than the atmospheric pressure, the evaporation will take place not
only from its surface, but fh>m CTery point in its interior ; the liquid particles
throughout the mass assuming the gaseous form, as rapidly as they are actuated by
the caloric, which subTcrts the hydrostatic equilibrium among them, to constitute the
phenomena of ebullition. This turbulent vaporisation takes place at any temperature,
CTen down to the freezing point, provided the pneumatic pressure be remoTed from
the liquid by the air pump, or any other means. Ebullition always accelerates eva-
poration, as it serves to carry off the aqueous particles not simply from the surface,
but from the whole body of the water.
The Tapours exhaled from a liquid at any temperature contain more heat than the
fluid fh>m which they spring ; and they cease to form whenever the supply of heat
into the liquid is stopped. Any volume of water requires for its conversion into
Tapour about y?o« iimu as much heat as is sufficient to heat it from the freezing to the
boiling temperature. The heat, in the former case, seems to be absorbed, being inap-
preciable by the thermometer; for steam is no hotter than the boiling water from
which it rises. It has been therefore called by Dr. Black, latent heat; in contradis-
tinction to that perceived by the touch and measured by the thermometer, which is
called setuiMe heat The quantity of heat absorbed by one Tolume of water in its con-
Tersion into steam, is about 1000^ Fahr. ; it would be adequate to heat 1000 volumes
of water, one degree of the same scale. Were the vessel charged with water so
heated, opened, it would be instantaneously emptied by vaporisation, since the whole
caloric, equiTalent to its constitution as steam, is present When upon the other hand,
steam is condensed by contact with cold substances, so much heat is set free as is
capable of heating about fiTC times its weight of water fW>m 32^ to 212^ F.
Bqual weights of vapour of any temperature contain equal quantities of heat ; for
example, the vapour exhaled fVom one pound of water, at 77® F., absorbs during its
formation, and will give out in its condensation, as much heat as the steam produced by
one pound of water at 212® F. The first portion of vapour with a tension » 30 inches,
occupies a space of 27*31 cubic feet ; the second, with a tension of 0-92 inch, occupies
a space of 890 cubic feet* Suppose that these 890 volumes were to be compressed
into 27*31 in a cylinder capable of confining the heat, the temperature of the vapour
would rise from 77® to 212®, in Tirtne of the condensation, as air becomes so hot by
compression in a syringe, as to ignite amadou. The latent heat of steam at 21 2® F. is
1180^ — 180 » 1000; that of Tapour, at 77®, is 1183— 45»1135 ; so that, in fact,
the lower the temperature at which the Tapour is exhaled, the greater is its latent heat,
as Joseph Black and James Watt long ago proved by experiments upon distillation
and the steam engine.
From the preceding researches it follows, that evaporation may be effected upon
two different plans : —
I. Under the ordinary pressure of the atmosphere; and that either,
* One pound avoirdupolf of water conUina 27 72 cubic Inches ; one cubic inch of water Tormi 1696
cubic inches of steam at 212P F. : therefore one pound of water will form 27'31 cubic feet of such steam ;
atidOi» : 30 :: 27*31 : S90 cubic iieet.
160 EVAPORATION.
A, by exteraal application of heat to boilers, with a, an open fire ; b, Bteam; c, hot
liquid media,
B, by evaporation with air ; a, at the ordinary temperature of the atmosphere ; i,
by carrentB of warm air.
2. Under progressively lower degrees of pressure than the atmospheric, dovn to
evaporation in as perfect a Tacuum as can be made.
It is generally iiffinned, that a thick metallic boiler obstmcts the passage of the
heat through it so much more than a thin one* as to make a considerable di£ferencein
their relatlre powers of evaporating liquids. Dr. Ure states that he made a series of
experiments upon this subject. Two cylindrical copper pans, of equal dimensions,
were provided ; but the metal of the one was twelve times thicker than that of the
other. Each being charged with an equal volume of water, and placed either apoD
the same hot plate of iron, or immersed, to a certain depth, in a hot solution of muriate
of lime, he found that the ebullition was greatly more vigorous in the thick than
in the thin vessel, which he ascribed to the conducting substance up the sides, above
the contact of the source of heat, being 12 times greater in the former case than in the
latter.
If the bottom of a pan, and the portions of the sides, immersed in a hot fluid mediam,
solution of caustic potash or muriate of lime, for example, be corrugated, so as to con-
tain a double expanse of metallic surface, that pan will evaporate exactly doable the
quantity of water, in a given time, which a like pan, with smooth bottom and aides,
will do immersed equally deep in the same bath. If the corrugations contain three
times the quantity of metallic surface, the evaporation will be threefold in the above
circumstances. But if the pan, with the same corrugated bottom and sides, be set
over a fire, or in an oblong flue, so that the current of flame may sweep along the cor-
rugations, it will evaporate no more water from its interior than a smooth pan of lilie
shape and dimensions placed alongside in the same flue, or over the same fire. This
curious fact Dr. Ure states he has verified upon models constructed with many modi-
fications. Among others, he caused a cylindrical pan, 10 inches diameter, and 6
inches deep, to be made of tin-plate, with a vertical plate soldered across its diameter;
dividing it into two equal semi-cylindrical compartments. One of these was smooth
at the bottom, the other corrugated ; the former afiPorded as rapid an evaporation over
the naked fire as the Utter, but it was far outstripped by its neighbour when ploogcd
into the heated liquid medium. .
If a shallow pan of extensive surface be heated by a subjacent fire, by a liqtud
medium, or a series of steam pipes upon its bottom •, it will give off less vapour in the
same time when it b left open, than when partially covered. In the former case, the
cool incumbent air precipitates by condensation a portion of the steam, and also op*
poses considerable mechanical resistance to the diffusion of the vaporous partiel^
In the latter case, as the steam issues with concentrated force and velocity from tbe
contracted orifice, the air must offer less proportional resistance, upon the kno^
hydrostatic principle of the pressure being as the areas of the respective bases of tne
communicatmg vessels. , . ,
In evaporating by surfaces heated with ordinary steam, it must be borne in mino
that a surface of 10 square feet will evaporate fully one pound of water per minote, or
725 X 10 a- 7250 gr., the same as over a naked fire ; consequently the condensing ajf*
face must be equally extensive. Suppose that the vessel is to receive of water 2500 lt*i
which corresponds to a boiler 5 feet long, 4 broad, and 2 deep, being 40 cubic feet d)
measure, and let there be laid over the bottom of this vessel 8 connected tubes, eac
4 inches in diameter and 5 feet long, possessing therefore a surface of 4'8 feet sqoare.
If charged with steam, they will cause the evaporation of half a pound of ^'^'-^^^
minute. The boiler to supply the steam for this purpose must expose a surface of 4
square feet to the fire. It has been proved experimentally that 10 square feet sorfac^
of thin copper can condense 3 lbs. of steam per minute, with a difference of ^^^^jjf^^
ture of 90 degrees Fahr, In the above example, 10 square feet evaporate 1 »b. o^
water per minute; the temperature of the evaporating fluid being 212° F, codsR'
quently 3:1 : : 90 : ^. During this evaporation the difference of the ^^V^^}^.^
therefore ■» 80°. Consequently the heat of the steam placed in connection *'^'' f^
interior of the boiler, to produce the calculated evaporation, should be, 212 + 80*
242°, corresponding to an elastic force of 536 inches of mercury. Were the tempe-
rature of the steam only 224, the same boiler in the same time would ?^^^^.
minished quantity of steam, in the proportion of 12 to 80 ; or to produce the sam
quantity the boiler or tubular surface should be enlarged in the proportion of 30
12. In general, however, steam boilers employed for this mode of evaporation are
such capacity as to give an unfailing supply of steam. f
We shall now illustrate by some peculiar fonns of apparatus, different systems
evaporation. Fig. 729 explains the principles of evaporating in vacua A B rep '
EVAPORATION.
161
sent* a pan or kettle eharged with the Uqaor to be evaporated. The aomewhat wide
oriiloe c, aeeored with a iorew-plog, serves to admit the hand for the purpose of
729
deanini^ it thoroughly out when the operatioo is finished ; A is the pipe of commnni-*
cation wi^ the steam boiler; 6 is a tube prolonged and then bent down with its end
plnnged into the liquor to be evaporated, contained in the charging back (not shown
in the figure). H is a glass tube communicating with the vacuum pan at the top and
bottom, to show by the height of the column the quantity of liquid within. The
eduction evaporating pipe c is provided with a stop-cock to cut off the communication
when required, t is a tube for the discharge of the air and the water from the steam-
case or jacket ; the refrigerator b is best formed of thin copper tubes about I inch in
diameter, arranged aig-zag or spirally like the worm of a still in a cylinder. The
small air-tight condenser f, connected with the efflux pipe/ of the refrigerator, is
famished bdow with a discharge cock y, and surrounded by a cooling case, for the
collection of the water condensed by the refrigerator. In its upper part there is a
tube k, also furnished with a cock, which communicates with the steam boiler, and
through which the pan a b is heated.
The operation of this apparatus is as follows: after opening the cocks c,/, g, and-
before admitting the cold water into the condenser e, the cock of the pipe k is opened,
in order that by injeeting steam it may expel the included air ; after which the cocks
k and ^ are to be shut The water must now be introduced into the condenser, and
the cock b opened, whereon the liquid to be eyaporated rises from the charging back,
through the tube b, and replenishes the vacuum pan to the proper height, as shown by
the register glass tube h. Whenever the desired eyaporation or concentration is
^ectcd, the cock c must be closed, the pipe A opened, so as to fill •the pan with steam,
and then the efflux cock a is opened to discharge the residuary liquor. By shutting
the cocks a and k, and opening the cock 6, the pan will charge itself afresh with liquor,
and the operation will be begun anew, after b has been shut and c opened.
The contents of the close water cistern r, may be drawn off during each operation.
For this purpose, the cock /must first be shut, the cold water is to li^ then run out of
the condenser a, and k and g are to be opened. The steam entering by k makes the
water flow, but whenever the steam itself issues from the cock g, this orifice must be
immediately shut, the cocky opened, and the cold water again introduced, where-
upon the condensed water that had meanwhile collected in the under part of the
refrigerator, flows off into the condenser vessel f. Since some air always enters with
the liquor sucked into the pan, it must be removed at die time of drawing off the
water from the two condensers, by driving steam through the apparatus. This
necessity will be less urgent if the liquor be made to boil before being introduced into
the vaenumpan.
Such an apparatus may be modified in sise and arrangement to snit the peculiar
You IL M
162 EVAPORATION.
object in Tiew, vhen it will be perfectly adapted Ka the eoneentraltoii of eitrMi df
tvery kind, aa well oa taliiw lolation* containiDg vegetable acidt or alkBlia. TW
interior vessel x b should be made of tinned or plated copper. For an ucoDiil li
Howard's vacnom pan, made upon the same principte, tee Sdgab.
When B boiler is eel over a fire, its bottom should not be placed too near Hu ptx.
lest il refrigerate the Same, and prevent that virid combustloo of the fuel esseuSil u
the maximum production of heat bj its means. The evil iofluence of leninp us
lillle room beloeea the grate and the copper maj' be illustrated bj a veij liniple
ciperimeot. If a small copper or porcelain capsule containing water be held oiir
tbe flame of a candle a lillle way abuve its apex, the flame will suffer no sbslesml if
brightaessor siic, but will continue to keep the water briskly boiling. If tlic opiiie
be now lowered into the middle of the flame, this will immediately lose its bngblwa,
becoming doll and smoky covering the bottom of tbe capsule with soot ; and. ovin;
to the imperfect combustion, though the water is now surronnded by the Bu», in
burned. For coal, the grale should be set higher and be somewbat smaller. >> i* i^l
door for feedinglhe flroi rf, an arch of flre-bricka over the hearth; e, a grste tin™?'
which the ashes fall Into the pit beneath, capable of beiog closed in front wl
extent by a sliding door b, a and c are two coppera encased in brickworks /l"
flue. At tbe end of the hearth near m, where the fire plays first upon the n^fi
the sole it made si mewhat lower and wider, tu promote the apreading of the nn
imder the vessel The second copper c, receives the benefit of the waste ^'^
nay be placed upon a higher level, ao as to discharge its concentrated liqaol 'V *
■top-cock or siphon into the first
Fig. 731 represents a pan for evapora^ag Uquids, which are apt, daring coaw'"'*
tion, to let fall crystals or other sediment. .
Tbeao woold be Injured either bf IM '"
playing upon the bottom of Ike pafr "'^
adhesion to it, they would allow ike a'^,'^
get red hot, and in that stale ran every r«
of being burnt or rent on the suddaa B"^
of a little liqoor through the i"'™'*''^
When Urge coppers have their «*'<"'
planted in loam, so that the flame "l^jj
in flues round their sidea, they are said »
cM-tet, , ,
A is a pear-shaped pan, charged wi» "
liquid 10 be eraporatod ; it i« fBrnuheii ™
a dome cover, in which there is sa op""!
with a flange/, fur attaching a tube, <■" ™'
duct the steam wherever it may be ■^"IT
a is tbe fire-place; i, the ash-p"- '"
conical part lerminatea below in ihem"''
furnished with a stop-cock al i" oofilt
Through the tobe cdrf. fVimished il»« *?:
below with the stop-cooks c and e\ "^j^
During the operation, ttw upper cock i
EVAPORATION. 163
it crmpontM ; bat the nnder cock c' ii Rhat. Tlie flame fron tlM fire-place pU;a
Tonnd the keole in tbe ipkoe (, and the emoke eecftpea downvardB thnnigh ihe floe i
into the chimnej. The lower cylindrieal part g Tcmaini thoa compara^Tety cool,
mud coUecta the crjatalline or other aoJid inatler. Alter acme time, the imder atop-
cock c', npco the aapply-iupe, ia la be opened to admit aome of the cold liquor into
the cylindrical neck. That cock being agaia shut, the a«dimeiit aettled, and the
large atop-coek (a hoTiaontal side valve would be prefetuble) h opened, tbe cryitala
are (uSeiied Ui descend intothe mbjaeent reoeivcr; after which the stop-cock Aiaihnt
and the opeiatinn ia cootinned. A conitraction upon thia principle ii well adapted
for beating dyeing coppers, in which the sediment should not be dutarbed.or eipoaed
to tbe action of the Bre. The fire-place should be built la for the brewing copper.
Fig. TSfi representa an obkmg evaporatiag pan, in vhicb the flamey ^r beUiag
alimg ita bottom, tama
Dp at ila flirther end,
plays back along iu
8Dl&x,aTid paaaeaoff
iDlo tbe chimney. A.
ia a rectangtUarreaari,
from 10 to 15 feet
long, 4 to 6 feel brood,
and I or 1} feet deep.
The fire bricka, Dpon -
Tbiehthe put retcs.are so arranged as to distribvte the flame eqoBlly along its bottom.
Leidenfroat in 175fl ('liuu^ ^ C%Miie)obaervedsome remarkable facta connected
with cTaporatioD, which have tinee received aome striking illBBtratioa ftvm the
experiments of M. Boaligny.
When water is thrown on a plate heated considerably above the boiling point of
water, the liqoid aatomea a spheroidal form,and thia condition liaa hence received the
name of the "ipbercndml atate." Thia water rolla aboat like melted crystal wilhoat
any ai^oa of ebollitioa, and K ia dissipated bat very alowly. The explanation nsnally
pven IB M ftdlows : — >* Tbe canse of the phenomena appears to be this, water eibibiU
anattractian for the eorfaM ofalmostallaolids, and well them; flnid mercary eibibits
the oppoeite property, or repulsion for moat snrfaces. Tbe attraction of water fbr
nrfoces brings it into the closest contact with them, and greatly promote! the com-
monieatiMi of heat by a heated vessel to the water contained in it. But heat appean
to develope a repnlaive power fat bodies, and it is probable that, above * pecnliar tem-
peratoie, (he healed metal no longer poeeessel this attraction for water. The water
not being attracted to the snrftce of the hot metal, and induced to spread over it, ii
not rapidly heated, and therefore Ixnls off slowly." — Oraiam.
The explanation given by this excellent aalhority on all melteia connected with
phyaico-chenical acience has been selected as representing feirly tbe prevailing
view. It is not, however, quite satisfkctory. The water is swd to be at a sensible
distance from the hot plate, and a layer of aqneons vaponr of very high temperature
is known to sarronnd tbe water, and yet the spheroidal Irater does not acquire the
boiling temperature. Here ia evidence of some peealiar, and as yet □nexplaioed
cooditKM, beloDginR, difaer to heat of a certain kind or degree, or to the molecules of
tbe bod^ onder ib mfloence.
Boat^ny obaerred that water may pas* into the spheroidal slate at any temperature
■bore S*<fiV^ and remain in that state imtil the temperatore falls to 388° F., when
evaporation rapidly eamei. Ether and alcohol pas* into the spheroidal atate at I ia° F.
■nd 373° F. A thermometer being plunged in liquid* while in the spheroidal stale,
indicaled tbe following temperatures j —
Water BOS-TOf.
Absolute alcobol 1G79
Ether • 936
HfdrooUorie ether 60-9
SolphnroDS acid ----.. 13-1
All these bring some degrees below the boiling tempenitBre of thoae fluids.
BoDligny has shown that the vapoor escaping &Dm water in the spheroidal stale,
■Ithongh it liBB a very elevated temperature, does not possess the usual eltuticity of
steam ; it does not exert an expansive power. But if the vessel ftnm which tbe
'Vapour is forming is allowed to cool, to a certain point, a degree of elaslieitj equal to
the elevated temperature of the vapour Is suddenly exerted. This is supposed by
Boatigny to explain many steam boiler eiploeions.
Whenever evaporation takes place, it should be remembered. It produces cold
— that is, it lowers the temperature of the body &om which the evapontion is taking
164
EXPANSION.
•place. Leslie, hj the eraporation of ether in Taciio» teaxe merciiTy. Thilorier 8o&
dified carbonic acid by the intense cold produced by its own eYaporatiom. Bontigny
froze water in a red hot vessel, by the evaporation of sulphoroos acid from the heated
vessel in which the water is in the spheroidal state.
Further remarks on these points, will be found under the heads respectively of
Coal, Steam Boii^eiis, Vapoub.
EXOSMOSE and ENDOSMOSE. As some manafactnring processes involT« the
phenomena expressed by these two words, it appears necessary briefly to explain tbem.
When two liquids are separated by a porous sheet of animal membrane, mglaced
earthenware, porous stone, or clay, these liquids gradually diffuse themselves; and
supposing salt and water to be on one side of the division, and water only on the
other, the saline solution passes in one direction, while the water, tiiiough with less
intensity, passes in another.
Instead of the two words introduced by Dutrochet, Professor Graham proposes the
use of the single term Osmose (from ^/<o;, impulsion).
It was supposed that there was, at the same time, an impulsive force acting from without
and another acting from within ; that there was indeed a current^otoin^ in, and another
flowing out It however appears to be proved that the osmose between water and saline
solutions, consists not in the passage of two liquid currents, but in the passage of particles
of the salt in one direction, and of pure water in the other. Professor Graham has
observed, that common salt diffuses into water, through a thin membrane of ox-bladder
deprived of its outer muscular coating, at the same rate as when no membrane is
interposed. This force plays an important part in the functions of life, and it will be
found to explain many of the phenomena associated with Dyeing, Tanning, &e.
EXOGENOUS. A botanical term, signifying growing by addition to the enter parts
of the stem.
The stem varies in structure in four principal ways. It is either formed by succes-
sive additions to the outside of the wood, when it is called exogenous, or by sncceasive
additions to its centre, when it is called endogenous^ or by the union of the bases of leav^
and the extension of the point of the axis, which is called acrogenous, or by simple
elongation or dilatation where no leaves or buds exist, as among Thalhgens, — JJndUg,
EXPANSION (Eng. and Fr.; Ausdehnungy Germ.) is the increase of bulk ex-
perienced by all bodies when heated, unless a change in molecular arrangement takes
place, as in the case of clays in the potter's kiln.
Table I. exhibits the linear expansion of several solids by an increase of temperature
from Z^ to 212<> Fahr.; Table II. exhibits the expansion in bulk of certain liquids.
TABLE I.— Ztneor Dilatation of SoUds hy Heat.
Dimensions which a bar takes at 212^ whose length at 32^ is l-OOOOOa
Dilatation
DIlatatioQ
Aathorlty.
io
in Volgv
Dedmalt.
Fractkns.
Glass tube -
^
m m
Smeaton
lOOOSSSSS
do.
«
m
Roy-
1-00077615
do.
•
•
Deluc*s mean
1 •00062800
lAs
do.
<■
m m
Dulone and Petit
1-00086130
TftS
do.
-
-
Lavoisier and Laplace
1-00061166
1^
Plate gUus
*
.
da do.
1-000890890
TtW
do. crown glass
.
do. do.
1 -00087572
Wn
do. do.
•
.
do. do.
100069760
nb
do. do.
•
_
do. do.
1 •00091751
do. red
.
m m
Roy- -
100080787
Deal
«
m m
Roy, as glass
.—
Platina .
•
m
Borda
1-00085655
do. -
•
-
Dulong and Petit -
1-00088420
1^
do.
m
«
Tfoughton •
1-00099180
do. and glass
m
•
' Berthoud
I-OOIIOOOO
Palladium -
»
•
Wollaston -
I-OOIOOOOO
Antimony -
«
•
Smeaton
1-00108300
Cast-iron prism
-
•
Roy -
1-00110940
Cast-iron -
•
.
Lavoisier, by Dr. Young
l-OOlllllI
Steel
-
•
Trougbton -
1-00118990
Steel rod -
_
.
Roy-
1-00114470
Blistered steel
•
•
Phil. Trans. 1795, 428
100112500
do.
-
m m
Smeaton
1-00115000
EXPANSION.
165
I
Dilatatloa
OIUUUoo
Authority..
in
Decimslt.
in Vulgar
Fractioni.
Steel not tempered -
»
LsToiuer and Laplace
1 00107875
■k
do. do. -
.
da da
1 -0010795^
ik
do. tempered yellow
-
da do.
lOOl 36900
do. dOb do.
.
da da
1O0J38600
dow da da at a higher heat
do. da
1-00123956
in
Steel ...
-
Trooghton -
1-00118980
Hard ited . . -
.
Smeaton
1 -00122500
Amiealed steel
.
Muschenbroek
1 -001 22000
Tempered steel
-
do. . -
1-00137000
Iron . • -
.
Borda
1-00115600
da - - -
.
Smeaton
1-00125800
Soft iron, forged -
-
LaToisier and Laplace
1-00122045
Round iroo» wire drawn
-
do. da
1-00123504
Iron wire • - -
.
Trottghton * ••
1-00144010
Iron • - -
.
Dulong and Petit
1-00118903
.]>
Bismnth . . -
.
Smeaton
1-00139200
Annealed gold
-
Muschenbroek
1-00146000
Gold - - -
-
Ellicot, by comparison
1-00150000
do. procured by parting -
-
Lavoisier and Laplace
1-00146606
i
da Paris stan&rd, unannealed
-
do. do.
1-00155155
do. da annealed
-
do. do.
1-00151361
bIt
Copper - . -
.
Muschenbroek
1-0019100
a •
do. - . -
-
LsToisier and Laplace
1-00172244
iIt
da - - -
w
da do.
1-00171222
ih
da - - -
.
Troughton -
100191880
d<\ * • .
•
DuIoDg and Petit
1-00171821
>h
Brass ...
.
Borda
1-00178300
da • - •
-
LsToisier and Laplace
1-00186671
do. - • -
-
do. da
1-00188971
Brass seale, supposed from Hambmrg
Roy - . -
1-00185540
Cast brass . . -
-
Smeaton * *
1-00187500
English plate-brass, in rod -
-
Roy-
1-00189280
do. da in a troagh form
do. -
1-00189490
Brass ...
-
Troughton •
1-00191880
Brass wire - - . -
.
Smeaton
1 -00193000
Brass
.
Muschenbroek
1-00216000
Copper 8; tin 1
.
Smeaton
1-00181700
SUver ...
•
Herbert
1-00189000
da - - -
.
Ellicot, by comparison
1-0021000
da - - -
.
Muschenbroek
1-00212000
do. ofeapel
.
Lavoisier and Laplace
1 •00190974
^
da Paris standard
.
do. do.
1-00190868
sb
SilTer - - . -
.
Troughton •
1-0020826
Brass 16, tin 1
.
Smeaton
1-00190800
Speculum metal
-
do.
1-00193300
Spolter solder; brass 2, sine 1
.
do.
1-00205800
Malacca tin • *
.
LaToisier and Laplace
100193765
tjl
Tin from Falmouth
.
da do.
1-00217298
«ii
Fine pewter - •
.
Smeaton
1-00228300
Grain tin -
.
do.
1-00248300
Tin - - -
.
Muschenbroek
1 -00284000
Soft solder; lead S, tm 1 -
.
Smeaton
1-00250800
Zioc 8, tin 1, a little hammered
.
da
1 -00269200
Lead ...
.
Lavoisier and Laplace
1 -00284836
^
do. . • •
Smeaton
1 -00286700
Zinc ...
.
do.
1 -00294200
Zinc, hammered out \ inch per foot-
do.
1-00301100
Glass, from S20 to 21 S^ -
Dulong and Petit •
1-00086130
%
do. from212«>to392« -
.
do. da
1 00091827
do. from 392«> to 572° -
-
do. da
1-000101114
Tlie last two measurements by an air thermometer.
H 3
166
EXPANSION.
TABLE IL^Expansion of certain Liqmdi hy being heated from, 32° to 21S<>«
SttbttSDOM*
AnthorlCx.
Expansion
in
ExMBskm
In Vulgar
FracOoM.
Mercary - - - - -
Da]ong and Petit. -
0-01801800
i^
da in glass - - -
da do.
0-01543200
it
Water ftrom itt maximam density
Kirwan - • -
004332
h
Muriatic acid (sp. gr. 1*137)
Dalton - - -
0*0600
A
Nitric acid (sp. gr. 1-4Q) -
da - - -
01100
i
Sulphuric acid (sp. gr. 1'85 )
da - - -
0-0600
if
Alcohol (to its boiling point) ? -
do. -
0-1100
i
Water
da - - -
0 0460
4,
Water, saturated -with common salt
da . . -
0-0600
^
Sulphuric ether (to its boiling point ) ?
do. -
00700
A
'Fixed oils - - - - -
da - - -
00800
^
Oil of turpentine - - - -
da - - -
0 0700
A
■
1-00000,
0-9548,
1-04734 ;
0-9973587,
1-00265,
If the density of water at 39° be called
at 212° it becomes - - - -
and its volume has increased to - •
at 77° it becomes - - - - -
and its Tolnme has increased to only
which, though one fourth of the whole range of temperature, is only ^ of the tots!
expansion. Water at 60° F. has a specific gravity of - 0-9991253,
and has increased in volume firom 39° to 1*00008,
which is only about ^ of the total expansion to 212°, with qJ, of the total range of
temperature.
All gases expand the same quantity by the same increase of temperature, which
fW>m 32° to 212*=^ Fahr.eii{° »}, or 100 volumes become 1'375. For each degree of
Fahr. the expansion is ^y.
When dry air is saturated with moisture, its bulk increases, and its specific gravity
diminishes, because aqueous vapour is less dense than air, at like temperatures.
The following Table gives the multipliers to be employed for converting one vdnme
of moist gas at the several temperatures, into a volume of dry gas.
Temperatura.
Multiplier.
Temperature,
Multiplier.
63* F.
0-9870
64°
0-9799
54
0 9864
65
09793
55
0-9858
66
0-9786
56
0-9852
67
0-9779
67
0*9846
68
0-9772
58
0-9839
69
0^765
59
0-9833
70
0-9758
60
0-9Q27
71
0-9751
61
0-9920
72
0-9743
62
0-9813
73
0-9735
63
0-9806
'
l^voisier and Laplace arrived, after an extenshre series of experiments, at the two
important conclusions following : —
Ist. All solid bodies whatever, being graduaHy heated fh>m the temperature of
meltin|^ ice to that of boiling water, and Uien gradually cooled from the temperature
of boilmg water to that of melting ice, will be found to have exactly the same dimen-
sions at the same temperature during the process of heating and cooling; the gradual
diminution of bulk in cooling corresponding exactly wil£ the gradiud increase of
bulk in heating.
2nd. Glass and metallic bodies gradually heated from the temperature of melting
ice to that of boiling water, undergo degrees of expansion proportional to those <^
mercury at the same temperature ; that is to say, between die limits just men^ooed,
the expansion of the solid corresponding to two degrees of the thermometer, is twice
the expansion which corresponds to one degree, the expansion which corresponds to
J
EXTRACTS, 167
tbree degrees is three times the expansion which correspondfl to one degree, and so
on ; the quantity of expansion being multiplied in the same proportion as the number
of degrees through which the thermometer has risen is multiplied. See Heat,
Lanbur^M Cj/dopeduu
Experiments bj Fresnel, Forbes, Powell, Treyelyan, and Tyndal have a tendency
to prove that heat occasions a repulsion between the particles of matter at small dis-
tances. If a heated poker is laid slantingly on a block of lead at the ordinary tempe-
rature, it will commence to vibrate, first slowlv, and will increase with such rapidity
as to produce a musical note, which continues for some time, usually changing to an
octave at the termination. These results would appear to prove a movement amongst
the particles constituting the bar.
Some remarkable examples of expansion are fdmished by the influence of sunshine
on the Britannia Tubular Bridge.
The most interesting effect is that produced by the sun shining on one side of the
tube, or on the top, while the opposite side and bottom remain shaded and compara-
tively cool ; the heated portions of the tube expand, and thereby warp or bend the tube
towards the heated side, the motion being sometimes as much as 2^ inches vertically
and 2^ inches laterally.
While the tubes were supported on the temporary piers on the beach, these motions
were easily observed. An arm carrying a pencil was fixed on the south side of the
tabe, at the centre, and a board was fixed on a post independent of the tube, and at right
angles to it; the pencil was pressed against the board by a spring, and the rise and fall,
and the lateral motions of the tube, were consequently placed on the board. In this way
a very interesting diagram was taken daily. The lowest part of each figure is the
starting point, or normal position of the tube, to which the pencil always accurately
returns during the night. As soon as the sun rises in the morning it starts towards
the ri^t hand, rising obliquely, the top and one side of the tube being warmed, and
the bottom and opposite side remaining unaffected. It continues thus till one o'clock,
when the sun, having ceased to shine on the southern side, begins to warm the
northern side, the top still retaining its high temperature, the tube thus acquires a
nearly horisontal motion towards the left hand, the slight descent in the line indicating
the diminished effects of the sun on the top as it gradually sinks. The greatest deflec-
tion to the left hand is not attained until sunset, after which the tabe rapidly descends
in a uniformly curved line to its resting point In the summer time this point is hardly
attained before the rising sun compels it to commence its journey anew. When the
sun is frequently obseured by passing clouds, very curious disigniins Are obtained.
During the absence of the sun the tube begins to cool rapidly, and to return to its
normal position, every passing cloud is thus beautifully recorded.
The middle of the centre arch of Southwark Iron Bridge rises one inch in the
height of summer. Wfaflta great lengths of iron pipe are laid down for the convey-
ance of steam or hot water, sliding joints are necessary to prevent destruction either
of the apparatus or of the building in which it is placed.
The practical applications made of the expansion and contraction of metals by heat
are many. The tire of a wheel is put on hot, and by its contraction on cooling,
firmly binds the other parts of the wheel together ; boiler plates are riveted wiUi
red-hot rivets ; collars of metal are driven on while hot, and the like.
MoUard drew together the walls of a building that had bulged, by screwing up
ban of iron tight to the walls while they were hot, and a similar process was adopted
in the Cathedral of Armagh.
Playfair and Joule (Chemictd Society's Memoiri) have made a valuable series of re-
searches on the expansion of bodies by heat, principally salts ; these have not how-
ever any soflicient practical bearing to occupy our space.
EXPRESSED OILS. See Oils.
EXTRACTS. (Extraitg, Fr; Extracten, Germ.) The older apothecaries used
this term to designate the product of Uie evaporation of any vegetable juice or in-
fusion, or decoction ; whether the latter two were made with water, alcohol, or ether ;
whence arose the distinction of aqueous, alcoholic, and etherous extracts.
Foarcroy made many researches upon these preparations, and supposed that they
had all a common basis, which he called the extractive principle. But Chevreul and
other chemists have since proved that this pretended principle is a heterogeneous and
very vmriable compound. By the term extract therefore is now meant merely the
whole of the soluble matters obtained from vegetables, reduced by careful evaporation
to either a pasty or solid consistence. The watery extracts, which are those most com-
monly made, are as various as the vegetables which yield them ; some containing
chiefiy sogar or gum in great abundance, and are therefore innocent or inert ; while
others contain very energetic impregnations. The conduct of the evaporating heat is
the capital point in the preparation of extracts. They should be always prepared if
M 4
168 FACTORY, COTTON.
possible, from the jaice 6f the fresh plant, by sabjectiag its leflves <nr other snccnient
part, to the action of a powerful screw, or hydraulic press ; and the CTaporation shoold
be effected by the warmth of a water bath, heated not beyond 100° or 120 F. Steam
heat is now applied advantageously in some cases, where it is not likely to decom*
pose any of the principles of the plant But by far the best process for makbg
extracts is in vacao, upon the principles explained in the article Etaporation. It is
much easier to fit up a proper apparatus of this kind, than most practical men imagine.
The vacuum may either be made through the agency of steam, as there pointed oot,
or by means of an air-pump. One powerful air-pump may form and maintain a good
vacuum under several receivers, placed upon the flat ground flanges of so many bssios,
each provided with a stop-cock at its side for exhaustion. The air-less basin con-
taining the juice being set on the shelf of a water-bath, and exposed to a proper tem-
perature, will furnish in a short time a large quantity of medicinal extract, posscssiiig
the properties of the plant unimpaired.
For exceedingly delicate purposes, the concentration may be performed in the eold,
by placing saucers filled with the expressed juice over a basin containing snlphorie
acid, putting a glass receiver over them, and exhausting its air.
The use of the air-pump for evaporating such chemical substances as are retdilj
injured by heat, has been very coumion since Professor Leslie's discovery of the
efficacy of the combined influence of rarefied air and an absorbing surface of sulphone
acid in evaporating water at low temperatures. It has been supposed that the virtna
of narcotic plants in particular might be better obtained and preserved by evaporttioa
in vacuo than otherwise, as the decomposing agency of heat and atmospheric oxygen
would be thereby excluded. There is no doubt that extracts thus made from the
expressed juices of fresh vegetables possess for some time at least, the green aspect
and odour of the plants in far greater perfection than those usually made in the air,
with the aid of artificial heat. Dr. Meurer, in the Arckiv, der PHarmade for April,
1843, has endeavoured to show that the colour and odour are of no use in determioiog
the value of extracts of narcotics, that the albumen left unchanged in the extracts
made in vacuo, tends to cause their spontaneovs decomposition, and that the extracts
made with the aid of alcohol, as is the practice in Grermany, are more efficacious at
first, and much less apt to be injured by keeping. M. Baldenius has, in the same
number of the Archiv^ detailed experiments to prove that the juices of recent plants
mixed with alcohol, in the homcsopathic fashion, are very liable to spontaxieoos
decomposition. To the above expressed juicC) the Germans add the alcoholic tincture
of the residuary vegetable matter, and evaporating both together, prepare very powerfol
extracts.
F.
FACETTING. The process of cutting faces upon ornamental articles. Steel
jewellerv, such as beads, studs, buttons, — the ornaments on the hilts of dress-swords
and similar objects, are ground on horizontal laps with fine emery. Facets on gold
and silver are cut and polished on revolving wheels, after the same general metiiod
as that pursued by the lapidary for cutting facets on stones.
FACTORY. In the sense in which this term is introduced here, it is contracted
from manufactory ; meaning the place where workmen are employed in fabricathig
goods. To describe all the various fiictories, would be to describe all the diffJereDt
manufactures, or, at leasts the arrangements of the machines by which the raw material
is converted into marketable goods. There is but one kind of factory which will be
described in this place. The arrangements of a cotton factory fairly represent all the
arrangements for other branches of textile manufactures, and here this is specially
described. Under Silk, Wool, &c., will be found particulars of the machines used and
their general arrangements in these factories respectively.
Factory, Cotton (General Construction of). There is no textile substaoce
whose filaments are so susceptible of being spun into fine threads of uniform tvist,
strength, and diameter, as cotton wool. It derives this property from the smoothness,
tenacity, flexibility, elasticity, peculiar length, and spiral form of the filaments ; hence,
when a few of them are pulled from a heap with the fingers and thumb, they lay hold
of and draw out many others. Were they much longer they could not be so readilj
attenuated into a fine thread, and were they much shorter the thread would be deficient
in cohesion. Even the differences in the lengths of the cotton staple are of advantage
in adapting them to difierent styles of spinning and different textures of doth.
If we take a tuft of cotton wool in the left hand, and seizing the projecting fibres
with the right, slowly draw them out, we shall perceive with what remarkable &cUity
FACTORY, COTTON. 169
they gUde past each other, and yet retain their mntual connection, while they are
extended and arranged in parallel lines, so as to form a little riband susceptible of
considerable elongation. This demonstration of the dactility, so to speak, of cotton
irooU auoceeds still better upon the carded fleece in which the filaments have acquired
a oertain parallelism ; for in this case the tiny riband, in being drawn out by the fingers
to a moderate length, may at the same time receire a gentle twist to preserve its co-
hesion till it becomes a fine thread.
Hence we may imagine the steps to be taken or the mechanical processes to be
pursued in cotton spinning. After freeing the wool of the plant from all foreign
substances of a lighter or a heavier nature, the next thing is to arrange the filaments in
lines as parallel as possible, then to extend them into regular ribands, to elongate these
ribands by many successive draughts, doubling, quadrupling, or even octupling them
meanwhile, so as to give them perfect equality of sixe, consistence and texture, and at
the same time to complete the parallelism of the fibres by undoing the natural convo-
lotions they possess in the pod. When the rectilinear extension has been thus carried
to the fineness required by the spinner, or to that compatible with the staple, a slight
degree of torsion must accompany the further attenuation; which torsion may be either
momentary, as in the tube roving machine, or permanent, as in the bobbin and fly
frame. Finally, the now greatly attenuated soft thread, called tkfihe roving, is drawn
oot and twisted into finished cotton yam, either by continuous indefinite gradations
of drawing and twisting, as in the throstle, or by successive stretches and torsions of
considerable lengths at a time, as in the mule.
Mechanical spinning consists in the suitable execution of these different processes
hy a series of different machines. After the carding operation, these are made to act
simnltaneoosly upon a multitude of ribands and spongy cords or threads by a multitude
of mechanical hands and fingers. However simple and natural the above described
course of manu&ctnre may appear to be, innumerable difficulties stood for ages in the
way of its accomplishment; and so formidable were they as to render their entire
removal of late years in the cotton fiictories of England one of the greatest and most
lionourable achievements of human genius.
The various operations may be thus classified for fine spinning :—
1. The mixing and opening up or loosening the flocks of cotton wool, as imported in
the bags, so as to separate at once the coarser and heavier impurities as well as those
of a lighter and finer kind.
2. The wiUcmng, aeutcking or blowing, and lapping, to remove seeds and dirt, and
prepare the material in the form of a continuous lap or sheet for the next opera-
tion of
3. The carding, which is intended to disentangle every tuft or knot, to remove every
remaining impurity which might have eluded the previous operation, and finally to
prepare for arranging the fibres in parallel lines, by laying the cotton first in a fleecy
▼eb^ and then in a nband form.
4. The doubUng and drawing out of the card-ends or ribands, in order to complete
the parallelism of the filaments, and to equalise their quality and texture.
5. The rimng operation, whereby the drawings made in the preceding process are
greatly attenuated, with no more twist than is indispensable to preserve the uniform
contioaity of the spongy cords.
6. The fine roving and stretching come next ; the former operation being effected by
the fine bobbin and fly frame» the latter by the stretcher mule.
7. The gpinning operation finishes the extension and twist of the yam, and is done
either in a continuous manner by the throstle, or discontinuously by the mule : in the
ibrmer, the yam is progressively drawn, twisted, and wound upon the bobbins ; in the
latter, it is drawn out and twisted in lengths of from 56 to 67 inches, which are then
wonnd all at once upon the spindles.
8. The eighth operation is the winding, doubling, and singeing of the yams, to fit them
for the muslin, the stocking, or the bobbin net lace manufacture.
9. The packing press, for making up the yam into bundles for the market, concludes
this series.
iVb£e: — Yams spun for weaving into cloth, as named in the 8th operation, after
being wound, are at once warped, and after being sized, or dressed, are ready for the
loom.
10. To the above may be added the operations of the dressing machines, for fine
waips ; the tape leg machine, for medium counts of warps, say 2As. to 50s., and sizing
tronghs for warps of coarser counts.
11. The power looms.
12. The plaiting, or folding and measuring machine.
13. The presft for compretoing the bundles of cloth ready for delivery.
The site of the fiutory ought to be carefully selected in reference to the health of the
170 FACTORY, COTTON.
operatives, the cheapness of proTisions, the fiusilities of transport for the rawnuiieriab;
and the convenience of a market for the manufactured articles. An abundant supply
of labour, as well as fuel and water for mechanical power, ought to be primary con-
siderations in setting down a ikctory. It should therefore be placed, if possible, in a
populous Tillage, near a river or canal, but in a situation Aree from marsh malaria,
and with such a slope to the voider stream as may ensure the ready discharge of all
liquid impurities. These circumstances happily conspire in the Astricts of Stock-
port, Hyde, Staleybridge, Dukenfield, Bury, Blackburn, &c, and have eminently
fiivoured the rapid extension of the cotton manufiustures for which these places aie
pre-eminent
The better to illustrate the above-named requisites for cotton spinning and manu-
facturing, we proceed to a description of a mill at Stockport, Lancashire, containing the
large number of 61,400 throstle and mule spindles, and 18S0 power looms.
Sfr. E. M*Chtre*a Cotton. Factoiy. — The mill consists of a main body with two
lateral wings, projecting'forwurds, the latter being appropriated to store-rooms, a count-
ing-house, rooms for winding the yam on bobbins, and other miscellaneous purpoeea,
The building has six floors besides the attic story. The ground-plan comprehends a
plot of gpround 280 feet long by 200 broad, exclusive of Uie boiler sheds.
The right-hand end, a (^Jig. 733) of the principal building, is separated frxMn the
main body by a strong wall, and serves in the three lower stories for accommodating
two ninety -horse steam engines, which are supplied with steam from a range of hoilen
contained in a low shed exterior to the mill.
The three upper stories over the steam engine gallery are used for unpacking, sorting,
picking, cleanmg, willowing, and lapping Uie cotton wooL Here are the willow, the
blowing, and the lap machines, in a descending order, so that the lap machine occapies
the lowest of the three floors, bein^ thus most judiciously placed on the same level with
the preparation room of the buildmg. On the fourth main floor of the factory there
are, in the first place, a line of carding engines arranged, near and parallel to the
windows, as shown at B b, in the ground plan (Jig, 733), and, in the second place,
two rows of drawing frames, and two of bobbin and fly fhmies, in alternate lines,
parallel to each other, as indicated by d, c, d, c, for the drawing frames, and e, b, s, e,
loT the bobbin and fly frames in the ground plan. The latter naaohines are close to
the centre of the apartment
The two stories next under the preparation room are occupied with throstle frames,
distributed as shown at f f, in the ground plan. They stand in pairs alongside of
each other, whereby two may be tended by one person. These principal rooms are
280 feet long, and nearly 50 feet wide. The two stories, over the preparation room, tiz.,
the fifth and sixth floors from the ground, are appropriated to the mule Jennies, which
are placed in pairs fronting each other, so that each pair may be worked by one man.
Their mode of distribution is shown at a o, in the ground plan. The last single
mule is seen standing against the end wall, with its head-stock projecting in the
middle.
The ground floor of the main building, as well as the extensive shed abutting behind
it, marked by n, h, h, in the plan, is devoted to the power looms, the mode d placing
which in plainly seen at h, h, h.
The attic story accommodates the winding fhunes, and warping mills, and the warp
sizing machines, subservient to power weaving.
Some extra mules (self-actors), are placed in the wings.
We shall briefly sum up the references in the ground plan as follows : —
A, the ground apartment for the steam engines.
B, the distribution of the carding engines, the moving shaft or axis running in a
straight line through them, with its pulleys, for receiving the driving bands.
c c, the drawing frames.
D D, the jack, or coarse bobbin and fly frames.
E E, the fine roving, or bobbin and fly frames.
F, the arrangement of the throstle frames, standing in pairs athwart the gallery, in
the 2nd and 3rd flats.
0, the mules are here represented by their roller beams, and the outlines of their
head-stocks, as placed in the 5th and 6th stories.
B, the looms, with their driving pulleys projecting from the ends of their main axeiL
Sometimes the looms are placed m parallel straight lines, with the rigger pulleys of the
one alternately projected more than the other» to permit the free play of the driving-
belts I sometimes tiie looms are placed, as generally in this engraving, alternately to
the right and left, by a small space, when the pulleys may all project equally. The
former plan is the one adopted m Mr. Orrell*s milL
1, represents the cast-iron girders which support the floors of this fire-proof
building.
PACTOBT, COTTON.
172 FACTORY, COTTON.
K, K, are closets placed in each floor, in the recesses of a kind of pilasters bailt
against the outside of the edifice. These hollow shafts are Joined at top by horizontal
pipes, which all terminate in a chest connected with the suction axes of a fan, whereby
a coDstant draught of air circulates up the shafts, ventilates the apartments, and pre-
Tents the reflux of offensive effluvia from the water-closets, howcTer careless the work-
people may be. The closets towards the one end of the building are destined for the
men ; towards the other for the women.
i^ L, are the staircases, of a horse-shoe form, the interior space or shaft in the middle
being used for the teagle or hoist In the posterior part of the shaft a niche or groove
is left for the counter- weight to slide in, out of the way of the ascending and descending
platform.
M, M, are the two porters* lodges, connected to the corner of each wing by a handsome
iron balustrade. They are joined by an iron gate.
It will be observed that the back loom-shed has only one story, as shown in section
(^fig, 735). In the ground plan of the shed, n represents the roofing, of wood-woik.
The raiters of the floors rest at their ends upon an iron plate, or shoe with edges (as
it is caUed), for the girders to bear upon.
Two steam engines, of fully 100 horse-power each, and two of 50 horse-power each,
operate by cranks, which stand at right angles upon the shaft marked a both in the
plan and section. In the centre, between the bearings, is a large cog-wheel, driving a
smaller one upon the shaft marked h in both figures, to which the fly-wheel e belonga
That prime motion wheel is magnificent, and possesses a strength equal to a strain of
300 horses. From this shaft motion is giren to the main or upright shaft d^ in the
section, by two bevel wheels, visible at the side and on the top of the great block of
stone, about 5 toos weight (fig. 733), which gives a solid basis to the whole moTiog
apparatus.
The velocity of the piston in these steam engines is 240 ft per minute.
The first shaft makes 44'3 revolutions per minute ; the main upright shaft 58^
per minute. The steam engine makes 16 strokes per minute ; and the length of thrir
stroke is 7 ft 6 in.
As the one engine exerts its maximum force when the other has no force at all, and
as the one increases as the other diminishes in the course of each pair of strokes, the
two thus co-operate in imparting an equable impulsion.to the great gearing and ahaits,
which, being truly made, highly polished, and placed in smooth bearmgs of hard bran,
revoLre most silently and without those yibrations which so regularly recurred in the
old factories, and proved so detrimental to the accurate performance of delicate spinniitg
fkumes.
The steam for these four engines is supplied by four high pressure horixontal engines,
made by B. Goodfelluw of Hyde, the exhausted steam from which has still power
enough to drive the low pressure condensing engines. By an ingenious arrangement
the condensing water from these engines, while on its return to the river is made to
turn an 8 horse water-wheeL
A 12-horse auxiliary engine for driving the warping mills, sising and drying fVamea,
and mechanic's shop at night (in the event of br^ikages to the machinery), com-
pletes the power of this great mill, equalling over 1000 indicated horse-power, all the
steam being supplied by 5 boilers carrying 70 lbs. pressure.
Note. — Prior to the application of the principle of compounding or unitinffhigh and
low-pressure engines, the above-named four low pressure engines required nme boilers,
carrying 14 lbs. pressure, to supply them with sufficient steam; now, as we have shown,
boilers of smaller dimensions, carrying 70lbs. pressure, supply a sufficient quantity of
steam, for increased power, at a reduction of fifty per cent on the consumption of
coals.
The power for driving the machinery is conveyed from the engine rooms by shafting
in the usual manner.
^ To the horizontal ramifications from the upright shaft any desired Telocity of rota-
tion WAj^ be given by duly proportioning the diameters of the bevelled wheels of
communication between them ; thus, if the wheel on the end of the horizontal shaft
have one-half or one-third the diameter of the other, it will gire it a double or a triple
speed.
In the lowest floor, the second bevel wheel above the stone block drives the hori-
xontal shaft e, seen in the ground plan ; and thereby the horizontal shaft f, at right
angles to the former, which runs throughout the length of the building, as the other
did thirough its breadth, backwards. The shaft/ lies alonnide of the back window
wall, near the ceiling ; and from it the transverse slender uiafts proceed to the right
and left in the main building, and to the shed behind it, each of them serving to drive
two lines of looms. These slender or branch shafts are mounted with pulleys, each of
which drives four looms by four separate bands.
FACTORY, COTTON.
ttzi ini !□ [□ o n
in [a [pi la [a !□
[□ [□ [a [□ [□ !□
tainin !□[□!□
pninilizilniai
a [a ra !□ tn tarn
"[
174 FACTOBT, COTTON.
In tlie second and third floors, where the throstles are placed, the shaft d is seen in
the section to driTC the following shafts : •—
Upon the main apright shaft d (Jig. 735), there are in each of these stories two
horizontal berel wheels, with their fkces fronting each other (shown plainly OTer </</),
hy which are moved two smaller rertical berel wheels, on whose respectire axes are
two parallel shafts, one over each other, a g, which traverse the whole length of the
building. These two shafts move therefore with equal velocities, and in opposite
directions. They run along the middle space of each apartment ; and wherever they
pass the rectangular line of two throstle f^mes (as shown at f in the groond plan) they
are each provided with a pulley ; while the steam pulleys on the axes of two conti-
guous throsUes in one line are placed as fkr apart as the two diameters of the said shaft-
pulleys. An endless strap goes from the pulley of the uppermost horizontal shaft
round the steam or driTlng-pulley of one throsUe frame ; then up over the pulley 5,
the second or lower shaft, g ; next up over the steam pulley of a second throstle ; and,
lastly, up to the pulley of tiie top shaft, g. See gg in the throstle floors of the cro0
section.
In the preparation room, three horizontal shafts are led pretty dose to the oeOing
through the whole length of the building. The middle one, h (see the plan,^!^. 733),
is driven immediately by bevel wheels from the niain upright shaft d (fig, 734). The
two side ones i, t, which run near the window walls, are driven by two horizontal shafts,
which lead to these side shafts. The latter are mounted with puUeys, in correspondence
with the steam pulleys of the two lines of carding engines, as seen between the cards in
the plan. The middle shaft A, drives the two lines of bobbin and fly frames, b, b, b, s
(see cross section), and short shafts t, t^ seen in the cross section of this floor, mo^
from the middle shaft A, turning the gallows fixed to the ceiling, over the drawing
and jack frames, give motion to the latter two sets of machines. See c d in the cross
section.
To drive the mules in the uppermost story, a horizontal shaft k (see longitudinal and
cross sections, as well as ground plan) runs through the middle line of the bnildiug,
and receives motion flrom bevel wheels placed on the nudn upright shaft, </, immediately
beneath the ceiling of the uppermost storr. From that horizontal shaft, h^ at every
second mule, a slender upright shaft, /, passmg through both stories, is driven (see both
sections), llpon these upright branch shafts are pidleys in each story, one of which
serves for two mules, standing back to back against each other. To the single mules
at the ends of the rooms, the motions are given by still slenderer upright shafts, which
stand upon the head stocks, and drive them by wheel-work, the steps (top bearings)
of the shafts being fixed to brackets in the ceilmg.
In the attic, a horizontal shaft m m, runs lengthwise near the middle of the roof, and
is driven by wheel- work from the upright shaft This shaft, si, gives motion to the
warping mills and dressing machines.
This cotton mill having been erected according to plans devised and executed by
that very eminent engineer, Mr. Fairbaim, of Manchester, may be Justly reckoned a
model.of fkctory architecture. It is mounted with 1320 power-looms, of which e«<eh
100 require steam power equivalent to 25 horses to impel them, inclusive of the prepara-
tion and spinning operations competent to supply the looms with yam.
Ten looms, with the requisite dressing, without spinning, are considered to be equi-
valent to 1 horse power in a steam engine. Steam power equivalent to 1 horse vill
drive—
500 mule spindles,
300 self-actor spindles,
ISO throstle spindles of the common construction ; in which estimate the requisite
preparation processes are included.
In Mr. M'Clure^B mill there are in the throstle-fhime
floors ........ 27,200 spindles
And in the mule floors ..•-•- 34,200 „
Total yam spindles • 61,400
To which add, power-looms 1820, producing the product of the spindles, in the shape
of 300,000 yards of cloth in every week of 60 hours.
One of the most compact and best regulated modem fkctories, on the small scale,
which we visited in Lancashire, consisted of the following system of machines : —
1 willow, 1 blowmg machine, 1 lap machine, capable, together, of cleansing and
lapping 9000 pocmds of cotton per week, if required,
21 cards, breakers, and flnishers, which carded 5000 lbs. of cotton every week of
60 hours' work, being about 240 lbs. per card.
S drawing-frames, of 8 heads each.
FACTORY, COTTON. 176
8 coarse bobbin and fly frames.
7 fine bobbin and fly fhunes. No stretcher mole.
12 self-actor males, of Sharp and Boberts's eonstnietion, of 404 spindles each
-^4848 mule spindles.
10 throstle frames, of 236 spindlea each »2360 spindles.
7 dressing machines.
236 power-looms.
* 2 warping mills.
300 winding spindles for winding the warp.
The roTings have 4 hanks in the poond, and are spun into jam No. 38 on the
liinMtle, as well as the mule.
One bobbin of the roviog (compressed) lasts 5 days on the self-actors, and 6 days on
the throstles.
According to the estimate of Peel and Williams, of Manchester, 66 horses power of
a steam engme are cqaivalent to 396 power-looms, inclnding 16 dressing machines;
the cloth being 36 inches wide npon the arerage, and the yam varying in fineness from
12*6 to 40*8, the mean being 26*s. Here, the spinning and preparation not being
inclnded, the allowance of power will appear to be high. The estimate giren abore
assigns 10 looms, with the requisite dressing, to 1 horse ; but the latter assigns no more
than 6.
For the following experimental results, carefully made with an improved steam
engine Huftcator, npon the principle of Mr. Watt's construction, we are indebted
to Mr. Bennet, an engineer in Manchester. His mode of proceeding was to deter-
mine, first of all, the power exerted by the fitu^tory steam engme when all the machines
of the various floors were in action ; then to detach, or throw oat of gear, each system
of machines, and to note the diminution of force now exercised. Finally, when all the
machines were disengaged, he determined the power requisite to move the engine itself
aa well as the great gearing-wheels and shafts of the factory.
He found at the factory of J. A. Beaver, Esq., in Manchester, that 500 calico looms
(without dressing) took the power of 33 horses, which assigns 15 looms to 1 horse
power.
At Messrs. Birley's &ctory, in Bfanchester, he found that 1080 spindles in 3 self-
actor mules took 2*59 horses, being 417 spindles for 1 horse power ; that 3960 spindles
in 11 self-actors took 8*33 horses, being 475 spindles per horse power ; 1,080 spindles
in 3 self-factors took 2 horses, being 540 spindles per horse.
At Messrs. Clarke and Sons, in Manchester, that 585 looms in weaving fustians of
yarious breadths took 54 horses power, exclusive of dressing machines, being 1 1 looms
to I horse.
At J. A. Beaver's, on another occasion, he found that 1200 spindles, of Danforth*s
construction, took 21 horses, beiug 57 spindles per horse power ; and that io a second
trial the power of 22 horses was reqmred for the same effect, being 54 Danforth's
spindles per horse power.
An excellent engine of Messrs. Boulton and Watt, being tried by the indicator,
affi>rded the following results in a factory : —
A 60 horse boat-engine (made as for a steam boat) took
14^ horses power to drive the engine with the shafts 14*5
8^ blowing machines, with their 3 fans - - - 21*55
10 dressing machines •••... 10*25
12 self-actor mules of 360 spindles each (720 spindles
per horse power) ------ 6*00
6 Danforth*s throstle frames, containing 570 spindles (96
in each), being 93 spindles to 1 horse power - 6*20
At Bollington, in a worsted mill, he found that 106} spindles, inclnding preparation,
took 1 horse power upon throstles. N. B. There is no carding in the loug wool or
-worsted mannliicture for merinos.
At Bradford, in Yorkshire, he found that a 40 horse power boat-engine, of Boulton
and Watt*8» drove 598 calico looms, 6 dressing machines (equivalent to dress warp for
180 of the said looms), and I mechanics' workshop, which took 2 horses power. Other
engineers estimate 200 common throstle Spindles, by themselves, to be equivalent to
the power of 1 horse.
The shafts which drive the cards revolve about 120 times per minute, with a driving
polley of from 15 to 17 inches in diameter.
The shafts of the drawing and the bobbin and fly frames revolve from 160 to 200
tint s per minute, with pulleys ft'om 18 to 24 inches in diameter.
The shafts of throstle frames in general turn at the rate of ftx>m 220 to 240 times per
176 FAHLEBZ.
minnte, with driving pulleys 18 inches in diameter, when they are spinning yam
of from No. 35 to 40. The shafts of mules revoWe about 130 times per minute, with
pulley 16 inches in diameter.
The shafts of power looms reyolye from 110 to 120 times per minute, with pulleys
15 inches in diameter.
The shafts of dressing machines reyolve 60 times per minute, with pulleys 14 inches
in diameter.
Before quitting the generalities of the cotton manu&cture we may state the folloving
facts communicated also by Mr. Bennet : —
A waggon-shaped boiler, well set, will eyaporate 12 cubic ft of water with 1 cwt. of
coals ; and a steam-boiler with winding flues will eyaporate 17 cubic ft. with the same
weight of fuel : 7-f^ lbs. of coals of the former boiler are equivalent to 1 horse power
exerted for an hour, estimating that a horse can raise 33,000 lbs. 1 foot high in a
minute.
The first cotton mill upon the fire-proof plan was erected by the Messrs. Stmtt,
at Helper, in Uie year 1797 ; that of Messrs. Phillips and Lee, at Manchester, in ISOl ;
that of H. Houldsworth, Esq., of Glasgow, in 1802 ; and that of James Kennedy, at
Manchester, in 1805 ; since which time many good fiutorles have been built fire-proo^
like Mr. M*Clure*s.
The heating of the apartments of cotton factories is e£fected by a due distribution of
cast-iron pipes, of about 7 or 8 inches diameter, which are usually suspended a little
way below the ceilings, traverse the rooms in their whole length, and are filled with
steam from boilers exterior to the building. It has been ascertained that one cubic
foot of boiler will heat folly more than 2,000 cubic ft of space in a cotton milt nnd
maintain it at the temperature of about 75^ Fahr. If we reckon 25 cubic ft contents
of water in a waggon-shaped steam boiler as equivalent to I horse power, such a
boiler would be capable of warming 50,000 cubic ft of space ; and therefore a 10
horse steam boiler will be able to heat 500,000 cubic fr. of air frt>m the average
temperature, 50°, of our climate, up to 75°, or perhaps even 80° Fahr.
It has been also ascertained that in a well-built cotton mill, one superficial foot of
exterior surface of cast-iron steam pipe will warm 200 cubic ft of air. In common
cases for heating churches and public rooms, we believe that one-half of the above
heating surface will be found adequate to produce a sufficiently genial temperature
in the air. The temperature of the steam is supposed to be the same with that
in Mr. Watt's low-pressure engines, only a few degrees above 212° — ^the boiling point
of water.
The pipes must be freely slung, and left at liberty to expand and contract under
the changes of temperature, having one end at least connected with a flexible pipe of
copper or wrought iron, of a swan-neck shape. Through this pipe the water of
condensation is allowed to run ofif. The pipes should not be laid in a horizontal
direction, but have a sufficient slope to discharge the water. The pipes are cast from
half an inch to three-quarters thick in the metaL In practice the expansion of steam
pipes of cast-iron may be taken at about one-tenth of an inch in a length of 10 fieeC,
when they are heated from a little above the freezing to the boiling point of water.
The upper surface of a horizontal steam pipe is apt to become hotter than the bottom,
of the water be allowed to stagnate in it $ the difference being occasionally so great as
to cause a pipe 60 feet long to be bent up two inches in the middle.
In arranging the steam pipes provision ought to be made not only for the discharge
of the water of condensation, as above stated, but for the ready escape of the air; other-
wise the steam will not enter freely. Even after the pipes are filled with steam, a
little of it should be allowed to escape at some ext.'^me orifice, to prevent the re-
accumulation of air discharged from the water of the steam boiler. Li consequence
of water being left in the pipes serious accidents may happen ; for the next time
the steam is admitted into them, the regularity of heating and expansion is im-
peded, some part of the pipe may crack, or a violent explosion may take place, and
the joints may be racked to a very considerable distance, every way, from the place
of ruptuI^e, by the alternate expansions and condensations. The pipes should there-
fore he laid, so as to have the least possible declivity, in the direction of the motion of
the steam.
Formerly, when drying rooms in calico printing works were heated by iron stoves,
or cockles, their inmates were very unhealthy, and became emaciated ; since they have
been heated by steam pipes the health of the people has become remarkably good, and
their appearance frequently blooming.
Factobt is also a place where factors meet to dispose of goods, as Tea fkctories,
&c. &C.
FAHLERZ. Grey copper-ore, called also Panabase, from the many oxides it
contains, and TetrahedriU from its form.
FATS.
177
Tke aitaljsis of a eiTstalited specimen from Hoel Protper, in Cornwall, gave
Copper -
- 3018
Antimony -
- 23-66
SUver -
- traces
Arsenic
- 4-40
Iron
- 6-99
Sulphur
- 25-04
Zinc
traces
Specimens from Baden and Freiberg haye been found to contain as much as from
IS to 31 per cent, of silver. The fbllowing analysis by M. Rose, of grey copper ore,
or Fahlers» will show the variation in composition of this interesting mineral : —
Sulphur.
Antimony.
Copper.
1. St. Marie Auxillines, in Alsace
26-85
12-46
40-60
2. Gersdorf, Freiburg - - -
26-33
16-52
38-63
3. Kapnik, Hungary ...
25-77
23-94
37-98
4. Dillenburg, in Nassau - - -
2503
25-27
38-42
5. Mine Zidda, at Clansthal
24-73
28 24
34-48
6. Mine Wenzel, near Wolfnach,
Baden
23-52
26-63
25-23
7. Mine Kabacht, near Freiburg
21-17
24-63
14-81
Besides Arsenic, Iron, Zinc, and Silver.
FAINTS is the name of the impure spirit which comes over first and last in the
distillation of whiskey; the former beuig called the strong, and the latter, which is
mnch more abundant, the weak faints. This crude spirit is much impregnated with
fcetid essential oil (fusel oil), it is therefore yery unwholesome, and must be purified
by rectification.
FALSE TOPAZ. A light yellow pellucid yariety of quartz crystal. It may be dis-
tinguished from yellow topaz, for which when cut it b frequently substituted, by its
difference of crystalline form, the absence of cleavage, inferior hardness, and lower
specific grayity. Found in the Brazils, &c.
FAN {JEvtntaU, Fr.; Fdcher. Germ.) is usually a semi-circular piece of silk or
paper, pasted double, enclosing slender slips of wood, ivory, tortoise-shell, whale-bone,
&c., arranged like the tail of a peacock in a radiating form, and susceptible of being
folded together, and expanded at pleasure. This well-known hand ornament is used by
ladies to cool their faces by agitating the air. Fans made of feathers, like the wing of a
bird, hs^ve been employed from time immemorial by the natives of tropical countries.
Ftm. is also the name of the apparatus for winnowing com, for urging the fires of
furnaces, and for purposes of ventilation. For an account of the powerful blowing
and ventilating fan machines, see Foundry and Venttlator.
FANG, a mining term, A niche cut in the side of an adit or shaft, to serve as an
air course. Sometimes the term afanging is applied to a main of wood pipes.
FARINA {Fcainej Fr. ; MehL, Germ.) is the flower of any species of com, or
starchy root, such as potato, arrow- root* &c See Bread and Starch.
FATS {GraisseSf Fr. ; Fette, Germ.) occur in a great number of the animal
tissues, being abundant under the skin in what is called the cellular membrane, round
the kidneys, in the folds of the omentum, at the base of the heart, in the mediastinum,
the mesenteric web, as well as upon the surface of the intestines, and among many of
the muscles. Fats yary in consistence, colour, and smell, according to the animals
from which they are obtained ; thus, they are generally fluid in the cetaceous tribes,
soft and rank-flayoured in the camiyorous, solid and nearly scentless in the ruminants,
usually white and copious in well-fed young animals ; yellowish and more scanty in the
old. Their consistence yaries also according to the organ of their production ; being
firmer under the skin and in the neighbourhood of the kidneys than ameng the
movable viscera. Fat forms about one-twentieth of the weight of a healthy animal.
But as taken out by the butcher it is not pure; for being of a vesicular structure it is
always enclosed in membranes, mixed with blood, blood-vessels, lymphatics, &c. These
foreign matters must first be separated in some measure mechanically, after the fat is
minced small, and then more completely by melting it with hot water, passing it through
a sieve, and letting the whole cool very slowly. By this means a cake of cleansed fkt
will be obtained.
Braconnot and Raspail have shown that solid animal fats are composed of very small
microscopic, partly polygonal, partly reniform particles, which are connected together
by very thin membranes. These may be ruptured by mechanical means, then sepa-
rated by triturating the fresh fats with cold water, and passing the unctuous matter
through a sieve. The particles float in the water, but eventually collect in a white
Vol. IL N
178
FATS.
granular crystalline appearance, like starch. Each of them consists of a Tetteolar in-
tegument, of the nature of stearioe, and an interior floid like elalne, vhich afterwards
exudes. The granules float in the water, but subside in spirits of irine. When
digested in strong alcohol, the liquid part dissolves, but the solid remaini. Tbeie
particles differ in shape and size, as obtained from different animals; those of the
calf, ox, sheep, are polygonal, and from j^ to ^ of an inch in diameter ; those of the
sow are kidney-shaped, and from 50 to <^ ; those of man are polygonal, aad from ^ to
^ ; those of insects are spherical, and at most ^ of an inch.
Fats all melt at a temperature much under 212^ F. When strongly beatei vitb
contact of air, they diffuse white pungent fumes, then blacken, and take fire. When
subjected to distillation they afford a changed fluid oil, carburetted hydrogen, sod ihe
other products of oily bodies. Exposed for a certain time to the atmosphere, tber
become rancid, and generate the same fiit acid as they do by saponiAoatioB.^ In tbeir
fresh state they are all composed principally of stearine, margarine, and oleine,vithi
little colouring and odorous matter ; and in some species, hircine, from the goat ;
phocenine, from the dolphin ; and butyrine from butter. By snbjectmg them to a
great degree of cold, and compressing them between the folda of blotting psper, a resi-
duum is obtained, consisting chiefly of stearine and margarine ; the latter of whidi
may be dissolved out by oil of turpentine.
Beef and Mutton Suet.— When fresh, this is an insipid, nearly inodorous fiit, of ft firm
consistence, almost insoluble in alcohol, entirely so, if taken from the kidDe^s ud
mesenteric web of the ox, the sheep, the goat, and Oie stag. It varies in ita vlutenea
consistence, and combustibility, with the species and health of the animals.^ Thej nur
all be purified in the manner above described. Strong sulphuric acid derelop^
readil;^ the acid fats by stirring it through melted suet Alkalies, by saponifieitioo,
give rise to one of the three acids, — the stearic, margaric, or oleic. Beef soet coossts
of stearine, margarine, and dieine ; mutton and goat suet contain a little hirdoe. the
specific gravity of the tallow of which common candles are made is, by Ure*s experi-
ments, 0-936. The melting point of suet is from 98<> to 104<» F. The proportion
of solid and fluid fat in it is somewhat variable, but the former is in mat^ kr]ger
proponion. Mutton suet is soluble in 44 parts of boiling alcohot, of 0*620 ; beef
suet in 44 parts. Marrow fat cansists of 76 of stearine, and 24 of oleine ; it meUs it
1150 F.
Hog*t lard is soft, fusible at SI*' F., Convertible, by an alkaline solotioa, iotoi
stearate, margarate, oleate, and glycerine. Its sp. grav, is 0*936, at 50^ F. It consists
of 62 of oleine, and 88 of stearine, in 100 parts.
Goo$e-fat consists of 68 oleine and 32 stearine. .
Butter^ in summer consists of 60 of oleine and 40 of stearine ; in winter, 0^ ^ ^|
oleine, and 65 of stearine ; the former substance being yellow and the other white. i(
differs, however, as produced from the milk of different cows, and also sccordmg to
their pasture.
The ultimate constituents of stearine, according to Chevreni, are, 79 csrhon; H •
hydrogen ; and 9*8 oxygen in 100 parts.
See Maboabinb, Oleinb, Soap, Stearins.
The following statement is given on the authority of Braconnot : —
Fresh butter in summer
^— ^— in winter
Hog*s lard
Ox marrow
Goose fat - -
Duck fat
Ox tallow
Mutton suet
Dr. Robert Dondas Thomson has given the following list of animal fhts and their
melting points; —
Badger fat
Beef tallow •
Calf -
Camel -
Cochineal fat
Cow*8 butter
96®
Duck's fat
98^
Dog
136*8
Fox
131
Hare -
104
Hog's lard
79.7
Horse grease
77°
79}
129
117J
80-5
140
PAtXTS.
Hunan iki •
770
Steariae (duek) -
Pheuiat
109
Cetine -
Turkey
113
Chloreftine •
Stearine (hamaa) -
ISO
CBntharides ht -
» (•be€p) -
109
Margarine (batter)
„ (oxen) -
111
Palimtine •
(hog) -
100
179
109<>
ISO
S78
9Si
105
115
M. Dumas nyi that batter contains no stearine. The pnriflcation and deeoloration
of fills has been the object of many patents. One of the best is to mix two per
cent, of strong salphorie aoid with a qoantity of water, in which the tallow is heated
for some time with mooh stirring ; to allow the materiab to cool, to take off the
SDpenatant &t, and to re-melt it with abundance of hot water. More tallow will
thus be obtained, and that considerably whiter and harder than is nsoally procnred by
tlie aselters.
Dr. Ure states that be has found that chlorine and chloride of lime do not improre,
but rather deteri(»ate, the appearances of oils and other ihtty bodies. According to
Appert, minced suet subjected to the action of high-pressure steam in a digester,
at 250^ or seo^ F., becomes so hard as to be sonorous when struck, whiter, and
capable when made into candles, of giTing a superior light. A convenient mode
of rtmdtrntg minced tallow, or melting it, is to put it in a tub, and driTe steam
through it from numerous orifices in ramifying pipes placed near the bottom.
Mr. Watt's plan of purifying fiits, patented in March, 1836, has been successful.
He employs dilate sulphuric acid, to which he adds a little nitric acid, with a very
small quantity of bichromate of potash, to " supply oxygen,** and some oxalic acid.
These are mixed with the fat in the steaming tub. When the lumps of it are nearlv
diasolTed, he takes for every ton of fat, one pound of strong nitric acid, dilated with
one quart of water ; to which he adds two ounces of alcohol, naphtha, sulphuric ether,
or spirits of tuipentiae; and after introducing this mixture, he continues the boiling
for half an hour. Hie fot is finally washed.
Others have proposed to use vegetable or animal charcoal first, especially for rancid
oils, then to heat them with a solution of sulphate of copper and oonunon salt, which
is supposed to preeipitate the fetid albuminous matter.
Mr. Prynne obtawed a patent in March, 1840, for purifjriag tallow for the candle-
maker, by heating it along with a solution of carbonate of potash or soda for 8 hours,
letting the whole cool, removing the tallow to another vesael, heating it by means of
steam np to 206<^ F., along with dry carbonate of potash (pearlasb) : letting this mix-
tore cool very slowly; and finally removinff the tallow to a vessel inclosed in steam,
so as to expel any subsidiary moisture. — NewUnCs Journal^ xxl 858.
A patent for a like purpose was obtained in June, 1842, by Mr. H. H. Watson. He
avails himsdf of the blanching power of oxygen, as evolved Arom permanganate of
potash (chameleon mineral), in the act of its decomposition by acids, while in contact
with the melted fiU. He prescribes a leaden vessel (a well joined wooden tub will
also serve) for operating upon the melted tallow with one-twentieth of its weight of
the manganate dissolved in water, and acidulated to the taste. The whole are to be
well mixed, and grsdoaliy heated firom 150° up to 212° F., and maintained at that
temperature for an hour. On account of the tendency of the dissolved man-
ganate to spontaneous decomposition, it should be added to the dilute acid, mixed
with the fot previously melted at the lowest temperature consistent with its fluidity.
Mr. Wilson, of Vauxhall, has applied centrifugal action to the separation of the
liquid from the more solid parts of fatty matters, employing in preference the hydro-
exiraetars used by Seyrig and Co. for drying textile fabrics. Mr. Wilson applies a
stoot cotton twill in addition to the wire-grating; and in order to avoid the necessity
of di|Eging the concrete parts, and to prevent them fhmi dogging the interstices for
the dischaj]ge of the oily matter, he pbuses the whole in a bag 8 inches in diameter,
and of such length thst when hud on the rotating machine against the grating the
two ends will nwet The speed of the machine must be kept below that at which
stearic add or stearine would pass ; which is known by the limpidity of the expressed
fluid. To take advantage of the liquefying influence of heat, he keeps the tempera-
tare of his own room about 2^ F. above that of the substances under treatment
The chemistfy of fot will be foond in Urt^t JHcHtmary of Ckemutry. For Imports,
&C., see TajLLOw.
FAULTS iFaiUet, Fr.), in mining, are disturbances of the strata which interrupt
the miner's operations, and put him at a loss to discover where the vein of ore or bed of
ooal has been ** ikroum " by the convulsion of nature.
A mineral vein, may be regarded as a fissure formed by the consolidation of the
rocks in which it exists, or bv some movement of the entire mass, produdng these
cracks at right angles to theline of greatest mechanical force ; these have been even-
N 2
180 FAULTS.
tDtllT filled in vilh the mlaenl or metaltifeioos mftlter wluch ve God la Ihm. Alta
Ihii bM taken plice. there faai som«Ciiiie« bMii a movemeDl of n portion of ihr gnKiiid,
BDd the mineral vein, or Iod*,tiu been TrBctared. A simpie illustration of tbii it ik bl-
lowmg,^. 736, wbere we have the minerHl lein dlalocated, and Bubwqoentl} to [fae dii-
locatioD tben has been ft fonnationof a string of spalhose iron, following die brndiip
of a crack formed by the moTemen't, which, in this case, has been less iW Iht widtb
of the lode. In thelarge majorilj of eiamples tb» " heaTe"or "throw"of iheWeii!
heenverj considerable. It is usual to apeak of s/aaJt as if the fissure bad adudljiumd
thelode. It should be understood that an actud movement of great matMt of llutdid
earth is implied, and consequently, the 2oiJe having been formed befbreUieiiMrTtli>Bit,il
is moved with tbe rock in which il is enclosed. Fig. 738 is the plan o(Teinsl,S,S.t,
and an Elvan course a a, which have been dislocated along the line &, c. ud tU lie
lodes nod the Elvao course moved. Id this case the moTement has probablj takm pin
iTom the North towards the South. This disturbance will be continned (o s pni
depth, and in /$, 137isBaectionahowiiig the dislocation of a lode into tbne[anL Ed
T3S 737
this case the marenient has probably been the mbsidence of that portion "C" f[^
containing the lode 5, and the further subsidence of that portion contsimng w ^
a i the condition of the surftce being subsequently altered bv denudalion. l« ^^
clinalionof alodeisfreqneiitly chang^ by these movements, An» A- ^''."^'tt*
to represent the original condition of the lode by a coovulaioo, tiie pordw ^ ^
ftlien away leaving a chasm between, and the " dip " or incliostion of ""^ v,
therefore materiaUy changed. The direction of the lode is frequently i"^ ^jj
these movements. Many lodes b Cornwall have a direction from the N. rft- ^
& of W, up to a fenit, on the other side of which the direction is changed ff™"j.
of E. to the N. of W. Where these distnrhances are of fn^uent occurrenee, ik
cutties of mining are greatly increased. t fg
The dislocations and obstructions found in coal-flelds, which render the W^
coal so difficult, and their mining so laborious and uncertain, are the toUo^'^f'
1. Di'Aei. S. Slipi or Faulu. 3. Hitcha. 4. Trouhla. ^ j^^
The first three, uifer dislocation of the strau ; the fourth, changes hi the bn
FAULTS.
181
740
1. A duke is a wall of extraneoiu matter, which diTidet all the beds in a coal-field*
Dikes extend not only in one line of bearing through coal-fields for many miles, but
ran sometimes in different directions, and have often irregular bendings, but no sharp
angular turns. When ftom a few feet to a few fiithoms in thickness, they occur some-
times in numbers within a small area of a coal basin, running in various directions,
and even crossing each other. Fig. 740, represents a ground plan of a coal-field,
intersected wih greenstone dikes. A B
and c i> are two dikes standing parallel
to each other ; b f and o h are cross
or oblique dikes, which diyido both
the coal strata and the primary dikes
A B and c D.
2. SUps or fatdts run in straight
lines through coal-measures, and at
every angle of incidence to each other.
Ftg, 741 represents a ground plan of
a coal-field, with two slips A B and c d,
the line of bearing of the planes of the
strata, which throw them down to the
outcrop. This is the simplest form of
a slipk jPi^. 742, exhibits i>art of a 1^
coal-field intersected with sups, like a
cracked sheet of ice. Here A B is a '^
dike; while the narrow lines show
faults of every kind, producing dislo-
cations Tarying in amount of shp from
a few to a great many fi&thoms. The fkults at the points a, a, a vanish ; and the
lines at o denote four small partial slips called hitches.
The effects of slips and dikes on the coal strata appear more prominently when
viewed in a vertical section, than in a ground plan, where they seem to be merely
walisy Teins, or lines of demarcation. Fig. 743 is a vertical section of a coal-fieldt
741
crop.
742
743
from dip to rise, showing three strata of coal a^b,e, a b represents a dike at right
angles to the plane of the coal-beds. This rectangular wall merely separates the coal-
measnresi, affecting their line of rise ; but farther to the rise, the oblique dike c d in-
terrupts ihe coals a, b, c, and not oxdy disjoins them, but has produced a movement
which has thrown them and their cpncomitant strata greatly lower down ; but still,
with, this depression, the strata retain their paraUelism and general slope. Nearer to
the outcrop, another dike, b f, interrupts the coals a, ft, c, not merely breaking the
oontinaity of the planes, but throwing tiiem moderately up, so as to produce a steeper
inclination, as shown in the figure. It sometimes happens that the coals in the com-
partment H, betwixt the dikes c and e, may lie nearly horizontal, and the effect of the
dike s, F, is then to throw
ont the coals altogether,
leaving no vestige of them
in the compartment k*
The effect of slips on
the strata is also repre-
sented in the vertical sec-
tion,^. 744, where OjbfC
are coeds with their asso-
ciated strata, A b is an
interaecting slip, which
throws all the coals of the
first compartment much lower, as' is observable in the second, Na 2; and from
the amount of the slip, it brings in other coal-seams, marked 1, 2, 3, not iq the
n3
182
FAULTS.
compartment No* 1. c &, is a slip prodnoing a similar ranlt, but not of the ame
magnitade i x 7 repreients a slip across the strata, rererse in direction to the former ;
the effect of which is to throw up the coals, as shown in the area Na 4. Sock
a slip occasionallj brings into play seams seated onder those marked ct, b^ e, n
Eeeo at 4, ft, 6 } and it may hi^pen that the coal marked 4 lies in the proloog-
ation of a well-known seam, as r, in the compartment Ka 3, when the case be-
comes pu2zling to the miner. In addition to the abore varieties, a number of slips or
hitches are often seen near one another, as in the area marked No. 5, where the indi-
vidual displacements are inconsiderable, but the aggregate dislocation may be great,
in reference to the seams of the 6th compartment
y^5 The resnlts of dikes and slips on a
horizontal portion of a field are exem-
plified in fy. 745. .Where the eoal-
measures are horiaontal, and the faohs
ran at a greater angle than 45^ to the
line of bearing, tfaej are termed "dip "
and **ri8e" fwolts, as ▲ b, c i^ k f. Tbi
MlomingJIg. 746, which ti an aceoiale
section of the Mostyn coal'^fieid, Flint-
shire, will show the amoont to which
those disturbances are experienced.
The letters mark with sufficient dis*
a. Worked oat.
b. DHto.
c. 5 jd. ooal worked eot.
tf. 3 7d. ditto.
t
Inferior coal.
Ditto.
Yard coal woriced oat.
4 ft. coal (tolerable).
i. Main coal, 6ft. C^rciy 1
J. 5 ft. coaL
k, fltone ooal.
A 3ft.coaL
tinctness the beds on either side of die
f&ults.
Coal viewers or engineers re^aitl the
dislocations now described as bemg sob-
Ject in one respect to a general law,
which may be thus explained:— Let
Jig, 747 be a portion of a coal-measure ;
A, being the pavement and b the roof
of the coal-seam. If, in pursuing the
stratum at c, a dike d ooeurs, standing at
right angles with the pavement, they
conclude that the dike is merely a partttion-wdl between the beds by its own thick-
ness, leaving the ooal-seam undisturbed on either side ) but if a dike f fonns> «b at b»
748
FEATHERS. 183
sa obtnttt Mgb vidi the paicment, tbay coneloda tliit the dike ii not ■ limple
paititioD between the KnO, bat bat dirovD np tha Mrenl leami Into the predica-
ment iliovti U a. Finall;, ihoold ■ dika a mika U i in leaie angla wltb th« pare*
tneot, the; coodode that the dike hat ihrairQ down the eoal measnrM into the poai-
Diltea and balls are denominated npthnnr or downthTOw, according to the powtion
tbcT are net vitta in working the mine. Thai in fig. 7U, if [he miner it adTuicing
to ihe rise, the dike a b obiioiulr doe* not change the direetioa ; bat c n is a down-
tbrow dike of a certain nomber of &thoms tovardj the rise of the buln, and e f is an
upthrow dike likewise towards the rise. On tha other hand, when the dikes are met
with by the miner in «oAiii|; ttam the rise to the dip, the name* of the aboTe dikes
would be reTencd ; for what u «□ upthrow la the first ease, becomes « downthrow in
the second, relatiTe to the mining operationa.
S. We haye seen that AiCclu are small and partial slips, where the disloeatton does
not cxeeed the thickuev of tha c«sl-seam; and the; are correetlyeMMgfa called s(^
bj Ihe miner. Fig. 71S reprs-
•ents the operstim of Ihe AilcAes
a, B, c. D, a. r, a, h, on the coal- C
Ineasnrct. Tbongh obserTcd in |
one (K two seams Of a field, tfaev
maj not appear in the rest, as w
the case whh dikes and ftnltt.
Id the abova deaeriptioo die
langnage of the mine has been
retained, bat in the esse of tha
dike, as of the /aJt-pntpa; it is DOt diat the dike has lifted the coal bed op or
down, bat daring Ihe conTnlsiTe moTements of the eartli, when those trap dikes were
being fened from below, great moremcDts were prodaoed on either side of the fisinres,
throDgh which the mtdlen matter tseended, and hence the alteration inthepoaitioii of
the beds, which were preriously, perhaps, nearly in a horisontal plane,
FEATHERS. (Pfoo, Fr. ; Fakni, Oerra.) "The most beaatlfU, the most com-
plex, and the moat highly eUbonied of all the eorerings of B»ii»infis, dne to the d«-
velopBent of the epidermal lyslem, is the plumage of hird*.' — Obsh.
A ftaihar consists ot the " q<^" the " Aa/t," and Ihe " now." The *«ne consists
of " barbs * and " borbales."
The f«t& is pierced by a lower and an o^er orifloe, and eoctaint a series of light,
dry, conical eapmlea, fitted one apon another, and nnited together by a central pedicle.
The diajl it slightly bent, the coocaire side is dirided into two snr&ces by a middle
loDgitn^nal line continaedfrom theupperorificeof cheqnill,dieoonTex side is smooth.
Both sides are oorercd with a homy material similar to that of the qoill, and they
enckae a pecnliHr white, soft, dastic sobstaace, called the ** pifA." Tha barU tie
aiuched to the tides of the ilian. The bari>iUt are giren at ftom eldier tide of the
tnrbe, and are somdimea limilarlj barbed tbemselres, as maybe seen in thebarbulea
of the long feathers of the peacock's taiL
The barbules are commonly short and close set, tOd earred in contrary dbetrtiooa,
so that two adjoining series of barboles interlock together and fana the mechaniEm
b; which the barbs are oompacted into the close and resisting Tana of the qnill, or
" feslher," properly to called. Whoi the barbolea are long and loose, they characterise
that fotnt of the feather which is properly called a " jMme," and snch are the most
Til liable products of the plumage of birds in a commercial point of view, litt-g. Ihe
piames of the ostrich.
The Dowm. — The lower faarbs in every kind of fMher are nsoslly tooae, fbrming
the down, which is increased in moat birds by what is called the ** Kceesory plune.
This it ntoally a soft downy tnft, but Tsriet in different species, and eiea in tha
restfaersofdifferent parts of the body of the ssme bird. The Tslneoffestbersfor bed
■taffing depends apon the proportion of kwae soA down that enten into their composi-
tion ) and as the " scctttory plame " in tha t>ody leathers of the swans, geese, and
ducks, is almost as bog as tlie feather fi-om whidi it springs, hence arises the com-
mercial Taloe of tbe feathers of tbose aqaatio birds. — Omn.
The first eoTering of the young bird is a down. In tnoct birds a eerlain portion of
the down leathen is retained with the tme ftethers, and this pn^rtion is nsoally
greatest in the aquatia birds.
It is most remarkable in the eider dnek (Amai wullitima). "The down of (he
eider combines, with its pecaliar softnasa, fineness, and lightness, to great a degree of
elasticily (hat the quantity of this beantifol material which might be compressed and
concealed between tha two hands of a man, will serre to staff the evrerlet of a bed."
184 FEATHERS.
Featben oonstitate the subject of the manafactare of the Piumassier, a name given
to the artisan who prepares the feathers of certain birds as ornaments for ladles and
for military men, and to him also who combines the feathers in yarions forma. We
shall content ourselves ^ith describing the method of preparing ostrich feathers, as mist
others are prepared in the same way.
Several qualities are distinguished in the feathers of the ostrich ; those of the male,
in particular, are whiter and more beautiful. . Those upon the hack and above the
wings are preferred ; next those of the wings, and lastly, of the tail. The down is
merely the feathers of the other parts of the body, which vary in length from 4 to 14
inches. This down is black in the males, and grey in the females. The finest white
feathers of the female have always their ends a little greyish, which lessens their
lustre, and lowers their price. These feathers are imported from Algiers, Tunis,
Alexandria, Madagascar, and Senegal; this being the order of their value.
The scouring process is thus performed : — 4 ounces of white soap, cut small, are
dissolved in 4 pounds of water, moderately hot, in a large basin ; and the solution is
made into a lather by beating with rods. Two bundles of the feathers, tied with
packthread, are then introduc^, and are rubbed well with the hands for five or six
minutes. After this soaping they are washed in clear water, as hot as the hand
can bear.
The whitening or bleaching is performed by three successive operations.
1. They are immersed in hot water mixed with Spanish white, and well agitated
in it ; after which they are washed in three waters in succession.
2. The feathers are azured in cold water containing a little indigo tied np in a fine
cloth. They should be passed quickly through this bath.
3. They are sulphured in the same way as straw hats are (see Sulfhubino) ; they
are then dried by hanging upon cords, when they must be well shaken from time to
time to open the fibres.
The ribs are scraped with a bit of glass cut circularly, in order to render them very
pliant By drawing the edge of a blunt knife over the filaments they assume the
curly form so much admired.
Those feathers which are of a dingy colour are dyed black. For 20 pounds of
feathers, a strong decoction is made of 25 pounds of logwood in a proper quantity of
water. After boiling it for 6 hours, the logwood is taken out, 8 pounds of copperas
are thrown in ; and, after continuing the ebullition for 15 or 20 minutes, the copper
is taken from the fire. The feathers are then immersed by handfiils, thoroughly
soaked, and worked about ; and left in two or three days. They are next cleansed in
'a very weak alkaline lye, and soaped three several times. When they feel very' soft
to the touch, they must be rinsed in cold water, and afterwards dried. White feathers
are very difficult to dye a fine black.
For dyeing other colours, the feathers should be previously well bleached by the
action of the sun and the dew ; the end of the tube being cut sharp like a toothpick,
and the feathers being planted singly in the grass. After fifteen days* exposure, tliey
are cleared with soap as above described.
Hose colour or pink, is given by safflower and lemon juice.
Deep red, by a boiling hot bath of Brazil wood, after aluming.
Crimson. The above deep red feathers are passed through a bath of cudbear.
Prune de Monsieur, The deep red is passed through an alkaline bath.
Blues of every shade,, are dyed with the indigo vat
Yellow ; after aluming, with a bath of turmeric or weld.
Other tints may be obtained by a mixture of the above dyes.
Feathers supply us with a soft elastic down on which we can repose onr wearied
frames, and enjoy sweet slumbers. Such are called bed feathers.
Ooose feathers are most esteemed. There is a prejudice that they are best when
plucked from the living bird, which is done thrice a year, in spring, midsummer, and
the beginning of harvest The qualities sought for in bed teaSiers are softness,
elasticity, lightness, and warmth. Their only preparation when cleanly gathered are
a slight beating to clear away the loose matter, but for this purpose they must be first
well dried either by the sun or stove. Stoving or hot air being also necessary to
remove any animal matter liable to putrefy.
The feathers of the eider duck, Ancu moUissima, called eider down, -possesa in a
superior degree all the good qualities of goose down. It is used only as a covering to
beds, and never should be slept upon, as it thereby loses its elasticity.
Quills for writing. These consist usually of the feathers plucked out of the wings
of geese. Dutch quills have been highly esteemed, as the Dutch were the first who
hit upon the art of preparing them well, by clearing them both inside and outside from
a fatty humour with which they are naturally impregnated, and which prevents the
ink firom flowing freely along the pens made with them. The Dutch for a long time
FELSPAR. 185
employed hot cinders or ashes to attain this end ; and their secret was preserved very
carefully, bat it at length tranipired, and the process was then improved. A bath of
very fine sand must be kept constantly at a suitable temperatnre, which is about 140^
F. i into this the quill end of the feather most be plnnged, and left in it a few instants.
On taking the feathers out they must be strongly rubbed with a piece of flannel, after
which they are found to be white and transparent. Both carbonate of potash in solution
and dilate solphnric acid hare been tried to effect the same end, but without success.
The yellow tint which gives quills the air of age, is produced by dipping them for a
short time in dilute muriatic acid, and then making them perfectly dry. But this
process most be preceded by the sand-bath operation.
Quills are dresKd by the London dealers in two ways ; by the one, they remain of
their natural colour ; by the other, they acquire a yellow tint. The former is called
the Dutch method, and the principal workman is called a Dutcher. He sits before a
small stove fire, into which he thrusts the barrel- of the quill for about a second, then
lays its root quickly below his blunt-edged knife, called a hook, and, pressing this
firmly with the left hand, draws the quill briskly through with his right. The l^d on
-which the quill is laid to receive this pressure is called the plate. A skilful workman
can pass 2000 quills through his hands in a day often hours. They are next cleansed
by being scrubbed by a woman with a piece of rough dog-fish skin, and then tied up
in bundles.
In the goose's wing, the five exterior feathers only are valuable for writing; the
first is the hardest and roundest of all, but the shortest ; the next two are the best of
the five. The heaviest quills are generally the best.
FECULA {Fecule, Fr. ; StdrkemefU, Germ.) sometimes signifies com flour, some-
times starch, from whatever source obtained ; and it is also applied to chlorophyll,
the green matter of plants. The term is applied to any pulverulent matter obtained
from plants by simply breaking down the texture, washing with water, and sub-
sidence.
FEEDER, a mining term, A small lateral lode falling into the main lode or
mineral vein.
FELL. The hide of an animal.
FELL-MONGER. The business of the fellmonger is to separate the wool fVom
the akin. The wool is sold to the woolstapler, and the stripped skins sent to the leather
dressers or parchment makers.
FELSPAR (OftftoM, Fr. ; FeUlspath, Germ.) is a mineral crystallising in oblique
rhomboidal prisms, susceptible of two cleavages ; lustre more pearly thtui vitreous ;
spec grav. 2*39 to 2*58 ; scratches ^lass, but is softer than quartz ; yields no water
when calcined ; fusible at the blowpipe into a white enamel ; not affected by acids.
The liquid left from its analytical treatment with nitrate of baryta, nitric acid, and
carbonate of ammonia affords on evaporation an alkaline residuum which precipitates
platina from its chloride, and appears from this, as well as other tests, to be potash.
Felspar consists of silica, €6*75; alumina, 17*50; potash, 12 ; lime, 1*25 ; oxide of
iron, 0-7 5. — {Rote,) This mineral is a leading constituent of ffranite ; some varieties
of which, by the decomposition of the included felspar, furnish tiie petuntze or Cornish
stone, so much used in the porcelain and best pottery manufiictnres.
The Felspars may be divided into four groups : —
I. Potash felspar (which often contains some soda) ; common feUpar, or ortkoclase;
and kuciie,
II. Soda felspar (or soda and potash) ; (Ubite, nfacoiite^ oiUgoclase, and nepkeline.
II L Soda and lime felspar (containing some potash), andesint^ vosgiU,
IV. Lime felspar ; anorthite, labmdorite^ tkiortaurite.
y» Lithia felspar, or peialite.
I. Orthoclasb, the common constituent of granite, of which it ordinarily composes
from 40 to 45 per cent, consists of silica, 65*85, alumina, 18*06, potash, 16'59 » 100*00.
It is colourless, or pale flesh-coloured, or yellow. The name is generally restricted
to the snbtranslucent varieties, there being many sub-varieties founded on variations
of Instre, colour, &c., to which other names have been given. Amongst the varieties
so comprehended under the general name of orthoclaro, the principal are adularia*
transparent or translucent felspars found in large crystals in granitic rocks. Moonstone
and snnstone are varieties of adnluia, which are described under their proper
letters. In addition to potash, some specimens of adnlaria contain more than four
per cent of soda.
GuLSflT 7SL8PAB (Sanidinj ice^spar in part), occurs crystallised in the form of a
clear transparent glass in trachytic and volcanic rocks.
MuBCHisoNiTE, named after the distinguished geologist and fonnder of the Silurian
system, is a yellowish-grey or flesh-red felspar from Dawlish, and from Heavitree,
near Exeter. It is remarkable for its opalescence.
186 FELSPAK.
Ertthbitb is a flesh-coloured felspar, occurring in amygdaloid near Kilpatriek. It
contains 3 per cent of magnesia.
Leucitb is not so hard as orthodase, is transparent and tnfhsibie. It ooenrs in
detached trapesohedral crystals of a white coloar, which, from the similarity of their
forms to the common yariety of garnet, have obtained the name of ** white gameL**
It is found abundantly in trachyte on the Rhine, between Lake Laaeh and Andemach,
and also in the older lavas of VesuTiua, some of which appear to be ahnoat entirely
composed of it " The leucitic lavas, of the neig^boniiiood of Rome, have beoi used,
for the last 8000 years at least, in the formation of millstonea." — Dana,
It is composed of silica, 55*1 ; alumina, 23'4 ; potash, 21*5»10OO.
II. Albitb, or CUaodandiU is frequently a constituent of granite, and, more
frequently than common felspar, of syenite and greenstone; bnt it often oceon
associated with the latter in the same granite, when it ma^ be distinguished by its
greater whiteness and translucency. It is composed of sihca, 68*7; alumina, 19*5;
soda, 11 '8 a 100*0.
Rtacoijte is supposed by Rose to be a mixture of felspar and nephelinc. It
resembles glassy febpar, and occurs in doubly oblique riiombic prisms. It consists of
silica, 51*86; alumina, 28*66 ; lime, 1*30; soda, 11*60; potash, 6*58 a 100-Oa
It is found in the trachytes of Bohemia and Hungary, in the lavas of Vesavioi;
and in pitchstone in the islands of Arran and Rum.
Oliooclass, or toda spodument, consists of silica, 62*3 ; alumina, 23*5 ; ioda, 14*2 =
lOO'O. It occurs in porphyry, granite, syenite, serpentine, and basalt At Tenerifle
it is met with in trachyte.
Nephbline, or Ehombaidaifekpart occurs in six-sided prisms, and is composed of
silica, 44*4; alumina, 83*6 ; soda, 16*9; potash, 5*1 « 100*0.
The name nepheline includes the crystallised Tarieties f^om VesuTins, while, mider
the name ElsBolite, are comprised the coarser massive Tarieties with a greasy lustre.
It is found in the older lavas of Vesuvius, and in the lava of Capo di Bove, near Rome.
III. Andesine occurs in a whitish syenite in the Andes, in the Vosges, and else-
where. It consists of silica, 60*16 ; alumina, 23*86 ; peroxide of iron, 1*65 ; magnena,
0*84; lime, 5*91 ; soda, 6*58; potash, 1*00; « 100*00.
Vosgite is Labradorite rendered hydrous by partial alteration. It is of a whitish
colour, sometimes with a shade of green or blue, and has a pearly or greasy lustre.
It consists of silica, 49*32; alumina, 30*07; peroxide of iron, 0*70; protoxide of naa-
ganese, 0*60; lime, 4*25; magnesia, 1*96; soda, 4*85; potash, 4*45; water, 3*15 «
99'35.--(i>e/eMe.) Found in the porphyry of Temuay in the Vosges.
IV. Akorthits occurs in white translucent or transparent crystals, with a Titreoas
lustre, inclining to pearly on the planes of cleavage. It consists of silica, 43-2 ;
alumina, 36*8 ; lime, 20*0. Occurs among the old lavas of Vesuvius in the ravines
of Monte Somma, and in the island of Procida, in the bay of Naples. It has also
lately been found by Professor Haughton, in syenitic dykes traversing limestooe
(forming 85 per cent of the rock), near Oarlingford in Ireland.
Thiobsauritb is an Icelandic variety of anorthite, and consists of nlica, 48*36;
alumina, 30*59 ; peroxide of iron, 1 -37 ; magnesia, 0*97 ; protoxide of mangaiieae, a
trace; lime, 17*16 ; soda, 1*13 ; potash, 0*62 » 100*20.-^G^tA.
Labradorite, or Labrador feUpar, consists of silica, 53*69 ; alumina, 29*66 ; lime^
12*13 ; soda, 4*50 « 100*00.
It occurs principally as a constituent of other rocks, in the lavas of Etna and Vesu-
vius, in the oriental verde antique of Oreece and other porphyries, as well as in certain
homblendic rocks, granites, and syenites. On the coast of labrador, whence it was
origindly brought, it is associated with hornblende, hypersthene, and magnetic iron
ore. Labradorite receives a fine polish, and on account of its beautiful chatoyant
reflections, it is valued for ornamental purposes and sometimes used in Jewellery. The
parts exhibiting the varied play of colours are disposed in irregular ^lots and psttchcs,
and the same spot, if held in differeut positions, displays various tints, of which violet
and red are the most rare.
The pla^ of colours is supposed to be produced by microscopic crystals of quarts
imbedded m the stone. (?)
It is manufactured into brooches, bracelets, snuff-boxes, &e. It looks best when
cut in plain, very flat cabochon, and a great deal of skill is required to divide the
stone in such a manner that the iridescent portions (on which its beauty depends)
may be displayed to the utmost advantage.
V. Petaute is remarkable as being the mineral in which Arfvedson first dis-
covered lithia. It is white, iVequently with a reddish tinge, and possesses a glistening
lustre and a lamellar structure. Translucent Not affected by acids. Emits a blue
phosphorescent light when gently heated.
It consists of silica, 77*9; alumina, 17*7; lithia, 3*1 ; soda, 1*3 » 100-0. The only
FERMENTATION. 187
known European locality is the iron mine of Uton, an islattd 35 milct S. £. of Stockholm,
It is fonnd in the United States, and in Upper Canada, near York, on JLake Ontario.
FELSPATHIC. Of or belong'mg to felspar.
FELTINQ iFeuiraffe, Fr. ; FUtem, Qerm.) is the process hy which loose flocks
of wool, and hairs of varions animals, as the heaver, rabbit, hare, &c., are mutuallj
interlaced into a compact textile fabric The first step towards making felt is to mix,
in the proper proportions, the different kinds of fibres intended to form the stuff; and
then, by Uie yibratory strokes of the bowstring, to toss them ap in the air, and to
cause them to £U1 as irregdlarly as possible, opon the table, opened, spread, and
scattered. The workman covers this layer of loose flocks with a piece of thick
blanket stuff slightly moistened; he presses it with his hands, moving the hairs
backwards and forwards in all directions. Thns the different fibres ^ interlaced, by
their ends pnrsaing ever tortnons paths ; their vermicnlar motion bemg always, how-
ever, root foremost. As the matting gets denser, the hand pressure should be in-
creased in order to overcome the increasing resistance to the decussation.
A first thin sheet of soft spongy felt being now formed, a second is condensed upon
it in like manner, and then a third, till the requisite strength and thickness be ob-
tained. These different pieces are successively brought together, disposed in a way
suitable to the wished-for article, and united by continued dextrous pressure. The
stuff must be next subjected to the falling nulL See Hat Manujactubb, under
which hcaA the process of felting is described.
FERMENT (Eng. and Fr. ; Hefr Germ.) is the substance which, when added
in a small quantity to vegetaUe or animal fiuids, tends to excite those intestine motions,
and changes, which accompany fermentation. It seems to be the result of an alteration
which vegetable albumen and gluten undergo with contact of air amidst a fermenting
mass. The precipitates or lees which fall down, when fermentation is finished, consist
of a mixture of the fermenting principle with the insoluble matters contained in the
fermented liquor, some of whiehy like hordeine^ existed in the worts, and others are
probably generated at the time.
To prepare a pure fennent, or at least a compound rich in that principle, the pre-
cipitate separated during the fimnentation of a clear infusion of malt, commonly called
yeast or barm, is made use of. This pasty matter must be washed in cold distilled
water, drained and squeezed between the folds of blotting paper. By this treatment
it becomes a pulvemlent mass, composed of small transparent grains, yellowish grey
when viewed in the compound microscope. It contains much water, and is therefore
soft, like moist gluten and albumen. When dried it becomes, like these bodies,
translucid, yeUowish brown, homy, hard, and brittle. In the soft humid state it is
insipid, inodorous, insoluble in water and aleohoL If in this state the ferment be
left to itieU^ at a temperature of from 60^ to 70^ F., but not in too dry a situation, it
putrefies with the same phenomena as vegetable gluten and albumen, and leaves, like
them, a residuum resembling old cheese. See FEUMENTATioif and Ysast.
FERMENTATION. (/^srstea/olMm, Fr. ; GSbnmg, GensL) A <^nge which takes
place, under the influences of air and moisture at a certain temperature, in the con-
stituent particles of either vegetable or animal substances. This change is indi-
cated by a sensible internal motion — the development of heat — the evolution of
gaaeoos products. Fermentation may be divided into several kinds, as —
Saccharine, Bntyric,
Acetic, Glyceric,
Alcoholic or Vinous, Lactic,
Putrefiictive, Mucous.
Of the latter examples but a brief notice is required. Mucoue fermentoHtm is esta-
blished when the juice of the beetroot or carrot is kept at a temperature of 100^ for
some time, when a tumultuous decomposition takes place. All the sugar disappears, and
the liquor is found to contain a large quantity of gum, and of mannite with lactic acid.
jMcHe FermaUaium, — If a scdution of one part of sugar in five parts of water be
made to ferment, by the addition of a small quantity of cheese or animal membrane,
at a temperature <k 9(fi or 100^, lactic acid is formed, which may be separated by
adding a little chalk, the lactate of lime depositing in crystalline grains. In lactic
fermentation mannite invariably is produced as a secondary product, the formation of
which is not explained. It has been suggested that the formation of mannite is con-
nected with the production of succinic acid, which Schmidt, in a letter to Liebig, states
that he has fbund in fermenting liquids containing sugar. He suggests the following
formula : —
C»HW + C*H"0* = C'E^O"
Mannite^ Succioic acid. prap« lugar.
188 FERMENTATION.
. Glyceric Fermentation, — When glycerine is mixed with yeast, and kept in avam
place for some weeks, it is decomposed and conyerted into metacetonic acid. ThU
fermentation resembles the last named. The glycerine, C*H'0*, forming metaeetonie
acid, C«H*0\ as sugar, CH'O", does lactic acid, OH^O*, by loss of the elements of
water. — Kane,
Butyric Fermentation. -^ If the lactic fermentation is allowed to proceed beyond the
point indicated for the formation of lactate of lime, the precipitate in part rc^issolves
with a Ycry copious evolution of hydrogen gas, and carbonic acid, and the liqaor
contains butyrate of lime. In this action two atoms of lactic acid, C^H'H)",
produce butyric acid, C'H'O', carbonic acid, and hydrogen gas.
Putrefactive Fermentation. See Putrefaction.
The three first named kinds of fermentation demand a more especial attention from
their importance as processes of manufacture. Under the heads respectivelj— Acetio
Acn>, Beer, Brewing, Distillation, Malt, and Wine, will be found eTeiythiDg
connected with the practical part of the subject ; we have therefore onJy now to deal
with the chemical and physical phenomena which are involved in the remarkable
changes which take place. When vegetable substances are in contact with air asd
moisture, they undergo a peculiar change (decomposition). Oxygen is absorbed aad
carbonic acid and water are given ofi^ while there is a considerable development
of heat This may take place with greater or less rapidity, and thus eremaeausk
fermentation, or combustion may be the result ; the spontaneous ignition of hay (as
an example) being the final action of this absorption of oxygen.
Saccharine Fermentation, — If starch, C"H»(y + 2HO, be moistened vith an infusion
of pale malt, it is rapidly converted into dextrine, C"H>*0", and hence into grape
sugar, C^'H^O"; this is especially called the saccharine fermentation, since sagaris
the result.
Acetic and Alcoholic Fermentation, — If sngar is dissolved in water, it will renan
perfectly unaltered if the air is excluded ; but if exposed to the air, a gradoal decom-
position is brought about, and the solution becomes brown and sour. Oxygen has \m
absorbed, and acetic acid produced. If, however,' the sugar is brought into contact vith
any organic body which is in this state of change, the particles of the sngar participate
in the process, carbonic acid is evolved, and alcohol produced. There are some sab-
stances which are more actiye than others in producing this change. Yeast is the moat
remarkable ; but blood, white of egg, glue, and flesh, if they have begun to potrefy. ve
capable of exciting fermentation ; yegetable albnmen and gluten being, however, more
active. Vegetable albumen, gluten, and legumin d iffer from most yegetable bodi^ in the
large quantity of nitrogen which they contain. These substances exist in all frnits, and
hence, when fruit is crushed, the sugar of the Juices in contact with the albnm^o^
gluten being then exposed to Uie air, oxygen is rapidly absorbed, the nitrogenooa body
begins to putrefy, and the sugar passes into fermentative activity. The necessity w
oxygen is at the commencement of the decomposition ; when the putrefaction of toe
albumen or gluten has once begun, it extends throughout the mass withoat in-
quiring any farther action of the air. These may he regarded as '^^'^^.rj'
ments. Yeast is an artificial one. This body will be more particularly descnoed.
See Teast.
To produce a vmous liquid, it is necessary that there shall be present sngar* or
some body, as starch or gum capable of conversion into sngar, a certain portion o
water, and some ferment— for all practical purposes ^(u^* and the tem|>erature mooi
be steadily maintained at about 80" F. Both cane and grape sugar yield alcohol Dy
fermentation, but Liebig considers that cane sugar, before it undergoes vinous '^'"^*
tation, is converted into grape sugar by contact with the ferment; and that, conse-
quently, it is grape sugar alone which yields alcohol and carbonic acid. /
Grape sugar, as dried at 212^, contains exactly the elements of two at^
alcohol and ifour of carbonic acid. As 2(C*HH)») and 400* arise from C'*H"0 .
Cane sugar takes an atom of water to form grape sugar. It follows therefore tw
cane sugar should in fermenting yield more than its own weight of carbonic api
and alcohol ; and it has been ascertained by experiment that 100 parts ^^^X^^^a
104, whilst by theory 105 should be produced, consisting of 5 1 -3 of carbonic acid, m
53-7 of alcohol — (JTane.) Dr. Pereira has given the following very inteUig^oie
arrangement to exhibit these changes : —
MATBRIAL. COVPOSITIOIT.
1 equivalent of *| T ^ ^*
crystallised cane I I eq. of I 8 „
lugar ... 171 }• grape -{ 8 „
1 equivalent of I sugar 160 I 4 „
water . . 9j Cl2 „
carbon 94 _--^4 eq. carbouit
carbon 48«,,..^ ' acid . • •'^
oxygen 64-^*<^v.,.^^
oxygen 32- -Z!>~-^ . .. , oj
bydrog.lS — -^>*. eq.alcoho' 'J^
180 180: lio *"
FERMENTATION. 189
These ftcts will sufficiently prove tliat yinooi or alcoholic fermentation is but a
metamorphosis of sagar into alcohol and carbonic acid.
Soch are the generally received yiews. We find, however, some other views pro*
mulcted which it is important to notice.
Ldebig calls pvire/aeHve/ermeiUaUomj^-'eyeary process of decomposition which, caused
by extmal inflnences in any part of an organic compound, proceeds through the
entire mass without the fhrther co-operation of the originsl cause. Fermentatum,
according to Liebig's definition, is the decomposition exhibited in the presence of
putrefying substances or ferments, by compounds nitrogenous or non-nitrogenous,
which alone are not capable of putrefaction. He distingoishes, in both putrefaction
and fennentation, processes in which the oxygen of the atmosphere continually co-
operates, from such as are accomplished without fbrther access of atmospheric air.
Lielug opposes the view which considers pntre&ction and fermentation as the
result of vital processes, Uie development of vegetable formations or of microscopic
animals. He adduces that no trace of vege^ formations are perceptible in milk
which is left for some time in vessels carefhlly tied over with blotting paper, not
even after fermentation has regularly set in, a large quantity of lactic acid having
been formed. He fhrther remarks o( fermentative processes, that alcoholic fermen-
tation having been observed too exclusively, the phenomena have been generalised,
while the explanation of this process ought to be derived rather ttom the study of
fermentative phenomena of a more general character.
Blondean propounds the view t£tt every kind of fermentation is caused by the
development of fimgi. Blondean states that alcoholic fermentation is due to a fungus
which he designates Tormtla eerevituB ; whilst another, PeniciUiwn glaucttm^ gives rise to
lactic fiermentatioD. The latter fermentation follows the former in a mixture of
30 grm. of sugar, 10 gnn. of yeast, and 200 c. c. of water, which has undergone
alcoholic fermentation at a temperature of about 20°, being terminated in about two
days. Beer yeast, when left in contact with water in a dark and moist place, contains,
according to Blondean, germs both of Torvula eertvUia^ and of PenicUIium glaucwn ;
the former can be separated by a filter, and will induce alcoholic fermentations in
sugar water, whilst the latter are extremely minute, and pass through the filter ; the
filtrate, mixed with sugar water, gives rise to lactic fermentation. Acetic fermen-
tation is due to the development of Torvula aceti ; sugar is converted into acetic acid,
without evolution of gas, if 500 grm. dissolved in a litre of water, be mixed with
£00 grm. of casein, and confined in contact for a month at a temperature of about 20^.
Tbe conversion of nitrogenous substances into &t (for instance, of casein, in the
mann&cture of Roquefort cheese ; of fibrin under similar circumstances), which
Blondean designated by the term fatty fermentation (fermentation adipeiue), is caused
by PenicUUum glaucvan or Torvula viridia ; and the former fungus is stated to act
likewise in butyric and in urea-fermentation (conversion of the urea into a car-
bonate of ammonia).
Opposed to this view Schubert has published an investigation upon yeast In
order to prove that the action of yeast is due merely to its porosity, he founds his
investigation upon some experiments of Brendecke (particularly in reference to the
statement that fermentation taking place in a solution of sugar in contact with porous
bodies is due to an impurity of sngar) ; according to which various porous bodies,
such as charcoal, paper, flowers of sulphur, &;c., to which some bitartrate of ammonia
is added, are capable of inducing fermentation in a solation of raw sugar. His ob-
servations are also based upon some experiments of his own, which seem to indicate
that porous bodies, even without the addition of a salt, are capable of exciting fermen-
tation in a solution of (pure ?) cane sugar. Whatever may be the means whereby
alcohoiie fermentation is induced, he states it to be indispensable that the body in
question should be exposed for some time to the inflaence of air, and that oxygen and
carbonic acid are absorbed by tiie ferment Both oxygen and carbonic acid, being
electro-negative substances, stand in opposition to the electro-positive alcohol, and
therefore predispose its formation, but only when they are highly condensed by the
powerful surface attraction of the yeast, or of any porous body. The electrical
tension, he states, may be increased by many salts, provided that the latter do not at
the same time chemically affect either tiie sugar or the ferment
C. Schmidt has commanicated the results of his experiments to the Annale
Chem, Pharm. After stating numerous experiments, he continues : " Nor are fungi
the primum movent of saccharic fermentation ; the clear filtrate obtained by throwing
almonds crashed in water upon a moist filter, soon induces fermentation in a solution
of urea and of grape sagar ; in the latter case, no trace of ferment cells can be dis-
covered under the microscope, not even after fermentation is fully developed. If the
solation, still containing sugar, is allowed to stand eight days or a fortnight after
fermentation has ceased, an exuberant development of cellular aggregations is ob-
190 FERMENTATION.
served, bat no putrefaction ensaes; the fungi, well washed and introdaeed iato a
fresh solution of grape sugar, continue to grow luxuriantly, indneing, howeTer, if it
all, but Tery weak fermentation, which rapidly ceases ; henoe the growth of fungi
during fermentative processes is but a secondary phenomenon. The incresseof &
residuary ferment, which occurs after yeast has been in contact with sagar, ariiei
from a development of ferment cellulose, which probably takes place at tl^ ezpeoM
of the sugar. If muscle, gelatine, yeast, &c., in a very advanced state of pabid de-
composition be introduced into a solution of i sugar in 4 water, all phenanena of
putrefaction disappear ; after a few hours, active fermentation sets in, ferment edk
being formed, and the liquid contuns alcohol, but no mannite. The insdirity of
crushed yeast is due, not to the destruction of the fungi, but to the chemicsl ehao^
which are induced in yeast during the considerable time necessary for complete eoo-
minutioD. The crashed cells, introduced into sugar water, give rise to the prodsc-
tioo of lactic acid, without evolution of gas.*' Schmidt is of opinion that fermcntatioa
is a process analogous to the formation of ether. He believes that one of the con-
stituents of yeast, together with the elements of grape sugar, gives rise to the fonniF
tion of one or several compounds, which are decomposed in statu naaetHii (like
sulpho-vinio acid), splitting into alcohol and carbonic acid.
We believe that the preceding paragraphs fidrlv represent the views which have been
promulgated upon the phenomena of change, which are in many respects 8nsl(>goBi
to those of combustion and of vitality, presented in the fermentative prooene^
Much has been done, but there are still some points which demand the esreiol it-
tention of the chemist
In a practical point 'of view, the question which arises from the alteratioD io tlie
specific gravity of the fluid by fermentation is a very important one, a kaowledge
of the original gravity of beer being required to fix the drawback allowed npon
beer when exported, according to the terms of 10 Vict c 5. By this set a dnwbick
is granted of 5s. per barrel of thirty -six gallons, upon beer exported, of which "the
worts used before fermentation were not of less specific gravity than 1*054, sod not
greater specific gravity than 1*081,** and a drawback of 7s. 6dL per barrel upon beer
of which ** the worts used before fermentatkn were not of less specific gravitj thu
1*081.** The brewer observes the original gravity of his worts by means of some
form of the hydrometer, and preserves a record of his observation. The re^eoae
officer has only the beer, fVom which he has to infer the original grsTity. Fron
the great uncertainty which appeared to attend this question, Profeaeon Gn*
ham, Hofmann, and Redwood were employed by the Board of Inkuid Reveooe to
discover how the original gravity of the beer m^t be ascertained most accoratelf
from the properties of the beer itselfl When worts are fermented, the sugar pa«ei
into alcohol, and they lose in density, and assume as beer a dififerent specific grantj
The gravity of the wort is called the original gravity — that of the beer, iter grav^
The report of Graham, Hofknann, and Redwood, upon •* original gravities," ^^
supposed to be in thje hands of every brewer ; but as some of the points examined
materially explain many of the phenomena of vinous fermentation, we have tiaof-
ferred a few paragraphs to our pages : —
*' As the alcohol of the beer is derived from the decomposition of asecbanne
matter only, and represents approximately double its weight of stareh ^P'^'^
speculative original gravity might be obtained by simply increasing the exuwn
gravity of the beer by that of the quantity of starch sugar known to be decomiw*"
in the fermentation. The inquiry would tiien reduce itself to the best mesns ^^^^^
tatning the two experimental data, namely, the extract gravity and the P'^P^'^'j^l
alcohol in the beer, particularly of the latter. It would be required to decide ▼D<<r
the alcohol should be determined from the gravity of the spirits distilled fron tK
beer ; by the increased gravity of the beer when its alcohol is evaporated off; hyt ^
boiling point of the b«Br, which is lower the larger the proportion of *J^^
present ; or by the refracting power of the beer upon li^^t — > various methodi ^
commended for the valuation of the spirits in beer.
** Original gravities so deduced, however, are found to be useless, being in ^'^
and always under the truth, to an extent which has not hitherto been at all *^^\^
for. The theory of brewing, upon a close examination <rf the processi provei w ^
less simple than is implied in the preceding assumption; and other changes *PP^^
occur in worts, simultaneously with the formation of alcohol, which woi^d ^^^J^
be allowed for before original gravities could be rightly estimated. It ^ '^
necessary to study the gravity in solution of each by itself, of the principal c^^!^
substances which are fbund in fermented liquids. These individual gravitiea den
the possible range of variation in original gravity, and they brought oat clesny
the first time the nature of the agencies which chiefly itfect the result ^^
•« The nse of cane sugar is now permitted in breweries, and the solution of s°P
FERMENTATION.
191
may be ttndied fint as the wort of simplest composition. The tables of the specific
gravity <k sugar solutions, constructed by Mr. Bate, have been verified, and are con-
sidered entirely trustworthy. The numbers in the first and third columns of Table I.,
which follows, are however, from new observations. It is to be remarked that these
numbers have all reference to weights, and not to measures. A solution of cane
sugar, which contains 25 grains of sugar in 1000 grains of the fluid, has a specific
gravity of 1010*1, referred to the gravity of pure water taken as 1000 ; a solution of
50 grains of eane sugar in 1000 grains of the fluid, a specific gravity of 1020*2, and
so on. The proportion of carbon contained in the sugar is expressed in the second
eolmnn ; the numbers being obtained tnm the calculation that 171 parts by weight
of cane sncar (C**H**0**) consist of 72 parts of carbon, It parts of hydrogen, and
88 parts en ozy^gen ; or of 72 parts of carbon combined with 99 parts of the elements
of water. It is useftil to keep thus in view the proportion of carbon in sugar so-
lutions, as that element is not mvolved in several of the changes which precede or
aecompany the principal change which sugar undergoes during fermentation, and
which changes only affect the proportion of the oxygen and hydrogen, or elements of
water, eomlmied with the earbon. The proportion of oxygen and hydrogen in the
altered sugar increases or diminishes during the changes referred to ; but the carbon
remains constant, and affords, therefore, a fixed term in the comparison of different
solntiooa
Tabls L — Specific gravity oftolutions of CoM-mgar in waUr»
Ome SusBT, In 1000 ptrU
bf woight.
Carbon In 1000 parti
\xr weight.
Specific GraTltj.
25
10*53
10101
50
21*05
1020*2
15
31-58
1030*2
100
42*10
1040-6
125
52-63
1051
150
63-16
1061-8
175
73-68
1072-9
200
84*21
1083-8
225
94-73
1095-2
250
105*26
1106-7
** When yeast is added to the solution of cane sugar in water, or to any other sac-
charine solution, and fermentation commenced, the specific gravity is observed to
fall, owing to the escape of carbonic acid gas, and the fonnation of alcohol, which
is specifically lighter than water; 171 grains of sugar, together with 9 grains of
water, being converted into 92 grains of alcohol and 88 grains of carbonic acid
(CH^ iO^> + HO - 2C«H«0* + 4C03). But if the process of fermentation be closely
watched, the fall of gravity in cane sugar will be found to be preceded by a decided
increase of gravity. Solutions were observed to rise from 1055 to 1058, or 3 degrees
of gravity, within an hour after the addition of the yeast, the last being in the usual
proportion for fermentation. When the yeast was mixed in minute quantity only,
such as Jv of the weight of the sugar, the gravity of the sugar solution rose gradually
in four dajrs from 1055 to 1057*91, or also nearly 3 degrees ; with no appearance, at
the same time, of fermentation or of any other change in the solution. This remark-
able increase of density is owing to an alteration which takes place in the constitution
of the cane sugar, which combines with the dements of water and becomes starch
sugar, a change which had been already proved by H. Rose and by I>uhrunihut, to
precede the vinoos fermentation of cane sugar. The same conversion of cane sugar
into starch sugar, with increase of specific gravity, may be shown by means of acids
as well as of yeast. A solution of 1000 ports of cane sugar in water, having the specific
gravity 1054*64, became with 1 part of crystallised oxalic acid added to it 1054*7 ;
and being afterwards heated for twenty-tibree hours to a temperature not exceeding
128^ Fahr., it was found (when cooled) to have attained a gravity of 1057*63 — an
increase again of nearly 3^ of gravity.*'
The di&rence between the gravities of solutions of cane sugar and starch sugar
are of great practical value, but these must be studied in the original ; the result how-
ever being ** that the original gravity of a fermented liquid or l^r must be different,
according as it was derived from a wort of cane su^ or of starch sugar."
The gravity of malt wort was determined to be mtermediate between that of pure
eane sqgar and starch sugar, and solutions containing an equal quantity of carbon ex*
hibited the following gravities: —
Cane sugar - 1072*9 Pale malt - 1074-2 Starch sugar - 1076*0
192 FERMENTATION.
Two other substances vere found to infinence the original graTity of die wortr
dextrin, or the gam of starch, and caramel Tables are given of the specific
gravities of these, from which the following results have been deduced -. —
Starch sugar - - - 1076
Dextrin - - - - 1066-9
Caramel - - - - 1062-3
Caramel is stated to interfere more than dextrin in giving lightness or apparent
attenuation to fermented worts, without a corresponding production of alcohoL
** Another constituent of malt wort, which should not be omitted, b the soluble
azotised or albuminous principle derived from the grain. The nitrogen was deter-
mined in a strong wort of pale malt with hops, of the specific gravity 1088, and con-
taining about 21 per cent of solid matter. It amounted to 0-217 per cent of the
wort, and may be considered as representing 8*43 per cent of albumen. In the sane
wort, after being fully fermented, the nitrogen was found to amount to 0*134 percent,
equivalent to 2*11 per cent of albumen. The loss observed of nitrogen and albumen
may be considered as principally due to the production and growth of yeast, which is
an insoluble matter, at the cost of the soluble albuminous matter. Solutions of egg-
albumen in water, containing 3*43 and 2-1 1 per cent respectively of that substance,
were found to have the specific gravities of 1004*2 and 1003*1. Hence a loss of
density has occurred during fermentation of ri degree on a wort of 1088 origiasl
gravity, which can be referred to a change in the proportion of albuminous matter.
It will be observed that the possible influence of this substance and of the greater or
less production of yeast during fermentation, upon the gravity of beer, are restricted
within narrow limits."
The reporters' proceed : —
" The process required for the determination of the original gravity of beer, most
be easy of execution, and occupy little time. It is not proposed, in Uie examination
of a sample, to separate by chemical analysis the several constituents which have
been enumerated. In fact, we are practically limited to two experimental observa-
tions on the beer, in addition to the determination of its specific gravity.
** One of these is the observation of the amount of solid or extractive matter still
remaining after fermentation, which is always more considerable in beer than in the
completely fermented wash of spirits. A known measure of the beer might be evapo-
rated to dryness, and the solid residue weighed, but this would be a troublesome
operation, and could not indeed be executed with great accuracy. The same object
may be attained with even a more serviceable expression for the result, by measoring
exactly a certain quantity of the beer, such as four fluid ounces, and boiling it dovn
to somewhat less than half its bulk in an open vessel, such as a glass flask, so as to
drive off the whole alcohol. The liquid when cool is made up to four fluid ounees,
or the original measure of the beer, and the specific gravity of this liquid is observed.
It has already been referred to as to the extract gravity of the beer, and represents a
portion of the original gravity. Of a beer of which the history was known, the original
gravity of the malt wort was 1121, or 121^ ; the specific gravity of the beer itself
before evaporation, 1043 ; and the extract gravity of the beer 1056*7, or 56-7^.
'* The second observation which can be made with sufficient facility upon the beer,
is the determination of the quantity of alcohol contained in it This information may
be obtained most directly by submitting a known measure of the beer to distilfaitioa,
continuing the ebullition till all the alcohol is brought over, and taking care to con-
dense the latter without loss. It is found in practice that four ounce-measures of the
beer form a convenient quantity for the purpose. This quantity is aocnrately
measured in a small glass flask, holding 1750 grains of water when filled up to a maik
in the neck. The mouth of the small retort containing the beer is adapted to one end
of a glass tube-condenser, the other end being bent and drawn out for the purpose of
delivering the condensed liquid into the small flask previously used for measuring the
beer. The spirituous distillate should then be made up with pure water to the
original bulk of the beer, and the specific gravity of the last liquid be observed by the
weighing bottle, or by a delicate hydrometer, at the temperatnre of SO^ Fahr. The
lower the gravity the larger will be the proportion of alcohol, the exact amount of
which may be learned by reference to the proper tables of the gravity of spirits. The
spirit gravity of the beer already referred to proved to be 985*25 ; or it was 14-05®
of gravity less than 1000, or water. The * spirit indication ' of the beer was there-
fore 14*05^ ; and the extract gravity of the same beer 56-7^.
^ The spirit indication and extract gravity of any beer being given, do we possess
data sufficient to enable us to determine with certainty the original gravity ? It
has already been made evident that these data do not supply all the factors necessary
for reaching the required number by calculation.
FERMENTATION.
193
** The fonnation of the extractive matter, vhich chiefly distarbe the original
gnr^tj, increaBes with the progresa of the fermentatioo ; that is, with the proportion
of alcohol in the fermenting liqaor. Bat we cannot predicate from theory anj
relation which the formation of one of these snhstancet should bear to the formation
of tlie other, and are nnable, therefore, to say beforehand that becanse so much
sugar has been oonyerted into alcohol in the fermentation, therefore so much sugar
has also been converted into the extractive substance. That a uniform, or nearly
nnifonn relation, however, is preserved in the formation of the spirits and extractive
sabfltanoe in beer brewing, appears to be established by the observations which
follonr. Such an uniformity in the results of the vinous fermentation is an essential
condition for the success of any method whatever of determining original gravities, at
least within the range of circumstances which affect beer brewing. Otherwise two
fermented liquids of this class, which agree in giving both the same spirit indication
and the same extractive gravity, may have had different original gravities, and the
aolutiou of our problem becomes impossible.**
The following table, one of several of equal value, gives the results of a particular
fermentation of cane sugar. " Fifteen and a half pounds of refined sugar were dis-
solved in 10 gallons of water, making 10} gallons of solution, of which the specific
gravity was 1055*3 at 60^ ; and after adding three fluid pounds of firesh porter yeast,
Uie specific gravity was 1055*95. The onginal gravity may be taken as 1055*3
(55-3°).
Table II. — Fermentaikn of Sugar* Wort of original gramtjf 1055*3.
1.
KiimtMr of
OtMerratloo.
n.
Period of
FermenuiioD.
III.
IndicatioQ.
IV.
Degrees of Extrsct
OraTity,
Degrees of Extract
Gravity U$i.
1
Days. Hours.
0 0
0
55-30
0-
S
0 6
1*59
52*12
3-18
3
0 12
2*57
47*82
7*48
4
0 19
3*60
43-62
11*68
5
0 S3
4*33
40*13
15*17
6
1 5
5-31
35-50
19*80
7
1 12
6*26
31-39
23-91
8
1 19
7*12
27-63
27*67
9
2 11
8*59
20-26
35-04
10
8 11
9-87
13-40
41-90
11
5 12
10*97
7*60
47-70
12
6 12
11-27
4*15
61-15
** Colomns m. and t. respectively exhibit the spirit which has been produced, and
the solid matter which has disappeared ; the first in the form of the gravity of the
spirit, expressed by the number of degrees it is lighter than water, or under 1000,
and the second by the iUl in gravityof the solution of the solid matter remaining
below the original gravity 1055*8. This last value will be spoken of as ' degrees of
gravity lost ; ' it is always obtained by subtracting the extract gravity (column iv.)
from Uie known original gravity. To discover whether the progress of fermentation
has the regularity ascrib^ to it, it was necessary to observe whether the same re*
lation always holds between the columns of * degrees of spirit indication * and * de-
grees of gravity lost.' It was useful, with this view, to find what degrees lost
corresponded to whole numbers of degrees of spirit indication. This can be done
safely from the preceding table, by interpolation, where the numbers observed follow
each other so closely. The corresponding degrees of spirit in4ication and of gravity
lost, as they appear in this experiment upon the fermetitation of sugar, are ns follows: —
Tablb III. — Fermentation, of Sugar^Wort of original gravity 1055*3.
Decrees of Spirit
ImUcation.
Degrees of Extract
Gravity lost.
Degrees of Spirit
IndicatloD.
Degrees of Extract
Gravity lost.
1
2
3
4
5
6
1*71
4*74
9-26
13-48
18-80
22-54
7
8
9
10
11
27-01
31-87
3712
42-55
47*88
Vol* n.
o
194
FERMENTATION.
** In two other fermentations of cane sngar, the degrees of gravity lost, found to
correspond to the degrees of spirit indication, nerer dMered from the numbers of tbe
preceding experiment, or from one another, more than 0*9^ of gravity lost '^'" '"
sufficiently close approximation.
** The following table is of mnch importance : —
This ill
Table IV. — Stabch-Sdgab.
Degrees of Spirit Indication, with corresponding degrees (^grtnitg lost
Beiitles the dfgreei of graTitj lost corresponding to whole degrees of tfilrtt in<UcatioD, the degree* of
gravity lost corresponding to tenths of a degree of spirit indication are added from alcoIaiMD.
Degrees of
Spirit
IndicatioD.
•0
•1
•2
•3
•4
•5
•6
•7
•8
■9
1-6
0
^.^
•2
•3
•5
•7
•9
l-O
1-2
1-4
1
1-9
2-1
2-4
2-7
3-0
3-3
36
3-9
4-S
4-6
2
50
5-4
5-8
6-2
6-6
7-0
76
8-0
8-5
<i-o
3
9-6
9-9
10-3
10-7
11-2
11-6
12-0
12-4
12-8
m
4
13-8
14-2
14-6
150
15-5
15-9
16-3
16-7
17-2
i:-:
5
18-3
18-7
19-1
19-5
199
20-3
20-8
21-2
21-7
m
6
227
23*1
23*5
239
24*4
24-7
25-2
25-6
26i
26-(>
7
271
27-6
28-1
28-6
29-1
29*6
30-0
30-5
31-0
31-5
8
320
32-5
33-0
33-5
34-0
34-5
35*0
35-5
360
36-6
9
37-2
37-7
38-2
88-7
39-2
39-7
46*3
40-8
41-3
4IS
10
42-4
42-9
43-4
44-0
44-5
450
45*6
46-1
46-6
471,
11
47-7
1
'* It is seen from this table that for b^ of spirit indication, the correspoodiog d^
grees of gravity lost are 18-8®. For 5-9° of spirit indication, the corresponding d^
grees of gravity lost are 22*2^.
" This table is capable of a yaloable application, for the sake of which it ^. f**"
strncted. By means of it, the unknown original gravity of a fermented ^4°'^
beer from cane sngar may be discovered, provided the spirit indication and extiirt
gravity of the beer are obiserved. Opposite to the spirit indication of the beer m t«
table, we find the corresponding degrees of gravity lost, which last, added to tw
extract gravity of the beer, gives its original gravity. . /^
" Suppose the sugar beer exhibited an extract gravity of 7-9® (1007-9), m.^'JJJ
indication of 11®. The hitter marks, according to the table, 47-7° of gravity i»
which added to the observed extract gravity, 7-9®, gives 55-6® of original grsTity w
the beer (1055-6)." ,
Similar tables are constructed for starch sngar, and for various worts vitb v»
without hops. - . ,^
After explaining many points connected with the problem, as it P***^
under varied conditions as it respected the original worts, the Report proceeds:—
" The object is still to obtain the spirit indication of the beer. The specific gn^J
of the beer is first observed by means of the hydrometer or weighing bottla-
extract gravity of the beer is next observed as in the former meUiod ; but the
for this purpose may be boiled in an open glass fiask till the spirits are S?"^*^.
new process does not require the spirits to be collected. The spiritless liqwp '*°^'
ing is then made up to the original volume of the beer as before. By losing tts ^P* ^^^
the beer of course always increases in gravity, and the more so the richer m a|
the beer has been. The difference between the two gravities is the new 'P*^' -j-
cation, and is obtained by subtracting the beer gravity from the extract g™^ J'
which last is always the higher number.
** The data in a particular beer were as follows : —
Extract gravity
Beer gravity . -
- 1044-7
- 1035 1
Spirit indication - - . . . 9-6®
" Now the same beer gave by distilhitiont or the former method, a spirit >"Jj^^
of 9*9°. The new spirit indication by evaporation is, therefore, less by OS ^^
the old indication by distillation. The means were obtained of c<>ii^P^"°^J|^L bf
indications given by the same fermented wort or beer in several hundred caieB>
FEBMENTATION. 195
adopting the practice of boiling the beer in a retort, instead of an open flask or
basin, and collecting the alcohol at the same time. The evaporation nniformly indi-
cated a quantity of spirits in the beer nearly the same as was obtained bv distillation,
but always sensibly less, as in the preceding instance. These experiments being
made upon fermented liquids of known original gravity, the relation coold always be
observed between the new spirit indication and tibe degrees of specific gravity lost by
the beer. Tables of the degrees of spirit indication, with their corresponding degrees
of gravity lost, were thos constructed, exactly in the same manner as the tables which
precede ; and these new tables may be applied in the same way to ascertain the
original gravity of any specimen of beer. Having found the degrees of spirit indi-
cation of the beer by evaporation, the corresponding degrees of gravity lost are taken
from the table, and adding these degrees to the extract gravity of the beer, also ob*
served, the original gravity is found. Thus the spirit indication (by the evaporation
method) dT the beer lately referred to, was 9*6°, which mark 43^ of gravity lost in the
new tables. Adding these to 1044*7, the extract gravity of the same beer, 1087*7 is
obtained as the original gravity of the beer."
The results of the extensive series of experiments made, were, that the problem
could be solved in the two extreme conditions in which they have only to deal with
the pare sogars entirely converted into alcohol.
** The real difficulty is with the intermediate condition, which is also the most fre-
quent one, where the solid matter of the beer is partly starch sugar and partly ex-
tractive} for no accurate chemical means are known of separating these substances,
and so determining the quantity of each in the mixture.
** But a remedy presented itself. The fermentation of the beer was completed by
the addition of yeast, and the constituents of the beer were thus reduced to alcohol
and extractive only, from which the original gravity, as is seen, can be calculated.
*' For this purpose a small but known measure of the beer, such aa four fluid
ounces, was careAiUy deprived of spirits by distillation, in a glass retort To the
fluid, when cooled, a charge of fresh yeast, amounting to 150 grains was added, and
the mixture kept at 80^ for a period of sixteen hours. Care was taken to connect
the retort, from the commencement, with a tube condenser, so that the alcoholic
vapour which exhaled from the wash during fermentation should not be lost When
the fermentation had entirely ceased, heat was applied to the retort to distil off the
alcohol, which was collected in a cooled receiver. About three-flfths of the liquid
were distilled over for this purpose ; and the volume of the distiUate was then made
up with water to the original volume of the beer. The specific ^vity of the last
sptritooos liquid was now taken by the weighing bottle. To obtam a correction for
the small quantity of alcohol unavoidably introduced by the yeast, a parallel expe-
riment was made with that substance. The same weight of yeast was mixed with
water, and distilled in another similar retort The volume of this second distillate
was also made up by water to the beer volume ; its specific gravity observed, and de-
ducted from that of the preceding spirituous liquid. This ^cohol was added to that
obtaiaed in the first distillation of the beer, and the weight of starch sugar cor-
responding to the whole amount of alcohol was calculated. This was the first result
** For the solid matter of the beer : the spiritless liquid remaining in the retort was
made up with water to the beer volume, and the specific gravity observed. A
eorrection was also required here for the yeast, which is obtained by making up the
water and yeast distilled in the second retort, to the original volume of the fser, and
deducting the gravity of this fluid from the other. The quantity of starch sugar cor-
responding to this corrected gravity of the extractive matter was now furnished by
the table. This was the second result
** The two quantities of starch sugar thus obtained were added together. The
specific gravity of the solution of the whole amount of starch sugar, as found in the
table, represented the original gravity of the beer.
** This method must give an original gravity slightly higher than the truth, owing
to the circumstance that the dextnn, albumen, and salts,- which are found among the
solid matters dissolved in beer, are treated as having the low gravity of extractive
matter, and accordingly amplified by about one-sixth, like that substance, in allowing
for them ultimately as starch sugar. The error from this source, however, is incon-
sfderable. It is to be further observed, that the error from imperfect manipulation,
of which there is most risk in the process, is leaving a little sugar in the extractive
matter from incomplete fermentation. This accident also increases the original
gravity deduced.- The process has given results which are remarkably uniform, and
is valuable in the scientific investigation of the subject, although not of that ready and
easy execution which is necessary for ordinary practice, and which recommends the
former method."
o2
196
FERRIC ACID.
Table V. — To be used in ascertaining Original Gravities by the DistiUation
Process.
Degrees of Spirit Indicai
ion tpiih
correnponding degrees c
>f gravity lost in
, Afalt WorU,
Degree* of
S iirit
Ind cation.
•0
•1
•2
•3
•4
•5
•6
•7
•8
•9
0
,
•2
-6
■9
1-2
1-6
1-8
2-1
2-4
2-7
1
3-0
8-3
3-7
41
4-4
4-8
5-1
5-5
5-9
6-2
2
66
7-0
7-4
7-8
8-2
8-6
9-0
9-4
9-8
10-2
3
10-7
111
11-5
12-0
12-4
12-9
13-3
13-8
14-2
147
4
151
15-5
160
16-4
16.8
17-3
17-7
18-2
18-6
19-1
5
19*5
19-9
20-4
20 9
21-3
21-8
22-2
22-7
23-1
23-6
6
241
24-6
250
25-5
26-0
26*4
26-9
27-4
27-8
28^
7
28-8
29-2
29-7
30*2
30-7
31-2
31-7
32-2
82-7
33-2
8
33-7
34-3
34*8
35 4
35-9
36-5
37-0
37-5
38-0
38-6
9
391
39 7
40*2
40-7
41-2
41-7
42-2
42-7
43-2
43 7
10
44 2
44-7
451
45-6
46-0
46*5
47-0
47-5
48-0
48-5
n
49-0
49*6
601
50-6
51-2
61-7
52-2
52-7
53-3
53-8
12
54-3
54*9
55-4
55-9
56-4
56-9
67-4
57-9
58-4
58-9
13
59-4
60-0
60-5
61-1
61-6
62-2
62-7
63-3
63-8
64-1
14
64-8
65-4
65-9
66-5
67-1
67-6
68-2
68-7
69-3
69-9
15
70-5
Table VL — To be used in ascertaining Original Gravities by the Evaporation
Process
Degrees of Spirit Indication with corresponding degrees of gravity lost in Malt Worts,
Degrees of
Spirit
•0
•1
•2
•3
•4
•5
•6
•7
•8
-9
Indication.
0
__
•3
•7
1-0
1*4
1*7
2-1
2-4
2*8
31
1
3-5
3-8
4*2
4*6
50
5*4
6-8
6-2
6-6
7-0
2
7-4
7*8
8-2
8-7
91
9-5
9-9
10*8
10-7
111
3
11-5
11-9
12-4
12*8
13-2
13*6
14-0
14*4
14-8
15-3
4
15-8
16*2
16-6
17-0
17-4
17*9
18-4
18-8
19-3
19-8
5
20-3
20-7
21-2
21-6
221
22-5
23-0
23-4
23-9
24*3
6
24*8
25-2
25-6
261
26-6
270
27-6
28-0
28-5
290
7
29-5
300
30-4
30*9
31-3
31-8
32'3
32*8
33-3
33*8
8
34*3
34-9
35*5
360
36-6
37-1
87-7
38*3
38-8
39-4
9
40-0
40-5
41-0
41*5
420
42-5
430
43*5
44-0
44-4
10
44-9
46*4
46-0
46*5
47-1
47-6
48-2
48-7
49-3
49-8
11
50-3
50*9
61-4
51-9
52-5
630
63*5
54-0
54-5
55-0
12
55*6
56*2
56-7
57-3
57-8
58-3
68-9
59-4
59*9
60-5
13
61*0
61-6
621
62*7
68-2
63-8
64-3
64*9
65-4
66-0
14
66-5
67*0
67*6
68-1
63-7
69-2
69-8
70*4
70-9
71-4
15
72-0
FERRIC ACID. (FeO*.) This new compound having been prescribed as a
source of supplying oxygen to persons confined in diving-bells and in mines, bj
M. Fay erne, claims notice in a practical work. M. Fremy is the discoverer of this
acid, which he obtains in the state of ferrate of potash, by projecting 10 parts of dry
nitre in powder upon 5 parts of iron filings, ignited in a crucible ; when a reddish
mass, containing much ferrate of potash, is formed. The preparation succeeds best
when a large crucible, capable of holding about a pint of water, is heated so strongly
that the bottom and a couple of inches above it, appear faintly, but distinctly red, in
which state the heat is still adequate to efiect due deflagration without decomposition.
An intimate mixture of about 200 grains of dried nitre with about one>half its wei|rht
of the finest iron filings, is to be thrown at once upon the side of the crucible. The
mixture will soon swell and deflagrate. The crucible being taken flrom the fire, and
the ignited mass being cooled, is to be taken out with an iron spoon, pounded, and
immediately put into a bottle, and excluded from the air, from which it would speedily
FERROCYANIDES. 197
attract moisture, and be decompoied. It is resolved by the action of water, espe-
dsJly with heat, into oxygen gts, peroxide, and nitrate 'of iron. This acid has not
been obtained in a f^ state ; it appears indeed to be scarcely capable of existing alone,
decomposing, as soon as liberated, into oxygen and ferric oxide. — Graham,
Mr. J. D. Smith prepares the ferrate of potash by exposing to a full red heat a mix-
tore of finely powdered peroxide of iron with four times its weight of dry nitre. It
has an amethyst hue, but so deep as to appear black, except at the edges. Oxyg«n is
rapidly evolved by the action of the sulphuric or nitric acid upon its solution. He
considers the atom of iron to exist in this compound associated with 3 atoms of
oxygen, or double the proportion of that in the red oxide. Hence 69 fprains of pure
ferric acid should give off 12 grains of oxygen, equal to about 35 cubic inches; but
how much of the ferrate of potash may be requisite to produce a like quantity of oxygen
cannot be stated, from the uncertainty of the operation by which it is produced.
FERROCYANIDE& The compounds of the radical ferrocyanogen. The latter
radical is bibasic, when, therefore, it combines with hydrogen to form ferrocyanic
acid, it takes up two atoms. These two atoms of hydrogen can be replaced by
metals as in ferrocyanide of potassium or pnissiate of potash, as it is commonly called.
See Prussiate of Potash. Ferrocyanogen consists of ON'Fe, which may also be
written Cy^Fe, or, for brevity's sake, Cfy.
The modes of preparing the ferrocyanides differ, according as the resulting sub-
stance b soluble or insoluble in water. The soluble salts, such as those with alkalies,
are prepared either by neutralising hydroferrocyanic acid with the proper metallic
oxide, or by boiling pmssian blue with the oxide, the metal of which it is intended to
combine with the ferrocyangen. Other methods may also be adopted in special cases.
The processes for preparing the ferrocyanides of the alkali metals on the large scale
will be described in the article Prussiate of Potash.
When the ferrocyanide is insoluble in water, it may be prepared by precipitating
a salt of the metal with ferrocyanide of potassium. Thus, m the preparation of the
reddish or purple ferrocyanide of copper,
2(CnO,SO*) + K*Cfy -CuKJfy + 2(K0,S0*>
The above equation written in full becomes : —
2(CttO,SO^ + K«C«N»Fe - CuK}«N»Fe + 2(KO,SO^.
Ferrocyanide of potassium is much used as a test for various metals, in consequence
of the characteristic colours of the precipitates formed with many of them. The prin-
cipal ferrocyanides with their colours and modes of preparation will be found in the
following list : —
Ferrocyanide of aluminium j^—Kn instable compound formed by digesting hydrate of
alumina with ferroprussio acid.
Ferrocyanide* of antimony and areenic, — Neither of these salts are known in a state
of purity.
Ferrocyanide of barium, — This salt may be prepared by boiling pmssian blue in
slight excess with baryta water and evaporating to crystalUsation.
Ferrocyanide of bismuth. — When a solution of ferrocyanide of potassium is added
to a solution of a salt of bismuth, a yellow precipitate is obtained. It becomes of a
greenish tint on keeping for some time.
Ferrocyanide of cadmium may be attained as a white precipitate on adding a solution
of ferrocyanide of potassium to a soluble salt of cadmium.
Ferrocyanide of calcium may be prepared in the same manner as that of barium,
but, owing to the sparing solubility of lime in water, we must substitute cream of
lime for baryta water.
Ferrocyanide of cerium is a white salt only sligfaUy soluble in water. Its properties
are very imperfectly known.
Ferrocyanide of chrotHium. — The protochloride of chromium gives a yellow pre-
cipitate with ferrocyanide of potassium.
Ferrocyanide of cobalt. — Salts of cobalt give a pale blue precipitate with ferrocyanide
of potassium. It appears to decompose on keeping, as its colour becomes altered.
Ferrocyanide of copper, — When ferrocyanide of potassium is added to a solution of
subchloride of copper, a white precipitate appears, which, on exposure, becomes con-
verted into a purplish red substance, apparently identical with the ordinary ferro-
cyanide of copper which falls down on the admixture of salts of the protoxide of
copper with solutions of ferrocyanide of potassium.
Ferrocyanide ofglueinum may be obtained, according to Berselius, under the form
of an amorphous varnish, by decomposing ferrocyanide of lead with a solution of sub-
sulphate of glucina.
Ferrocyanide of hydrogen constitutes ferroprussic acid.
Ferrocyanide of iron, orpruman blue, — This salt exists in several conditions, ac-
o3
. 198 FIBBES.
cording to the mode of preparadon. The ordinary salt is formed h y addmg a Mlntioi
of ferrocjanide of potassium to a solation of a persalt of iron. Hie following equa-
tion explains the reaction that ensues with the sesqnichloride : —
2(Fe«ClO + 3(CfyK»«3(CfyFe«) + 6KCL
Fenoeyatdde of lead is procured as a white precipitate by adding a solnttoD of
ferroeyanide of potassiam to a salt of lead.
Ferroeyanide of magnesium is probably best prepared by neutralising ferroprusie
acid with magnesia or its carbonate. It forms a pale yellow salt
Ferroeyanide of memganeee ma^ be obtained as a white precipitate, on adding ferro-
eyanide of potassiam to a solution of pure protochloride or protosolphate of nin-
ganese.
Ferroeyanide qf mercury. — This compound cannot be obtained in a state of poiitj
by precipitation. It has not been sufficiently examined.
Ferrocyanides of moiybdenunu — Molybdons salts give, with ferroeyanide of po-
tassium, a dark brown precipitate soluble in excess of the precipitant If a salt of
molybdic oxide be treated in the same manner, a precipitate is obtained, haTUg a
similar appearance, but insoluble in excess. Molybdates in solation give precipiuta
lighter in colour than the last.
Ferroeyanide of nickel is obtained under the form of a pale apple green precipitate,
on addition of prossiate of potash to a salt of nickel.
Ferroeyanide ofeilver. — Ferroeyanide of potassium gives a white precipitate with
silver salts.
Ferroeyanide of aodium may be formed by the action of caustic soda on pmssian blue.
Ferroeyanide ofetrontium can be procured precisely in the same manner as the cor-
responding barium salt substituting solution of caustic strontia (obtained fron the
nitrate by ignition) for baryta water.
Ferroeyanide of tantalum has probably never been obtained pure. Wollaaton found
that tantalic acid (dissolved in binoxolate of potash) gave a yellow precipitate with
prussiate of potash.
Ferroeyanide of thorium. — A white precipitate is produced by the action of solotioa
of prussiate of potash on salts of thorium.
Ferroeyanide of tin. — Pure salts of tin, whether of the per- or prot-oxide,giTe
white precipitates with ferroeyanide of potassiam.
Ferrocyanides of titanium, — Solutions of titanates give a golden brown precipitate
when treated with solation of ferroeyanide of potassium.
Ferrocyanides of uranium, — The protochloride gives a pale, and the perchlonde
a dark reddish brown precipitate with ferroeyanide of potassium.
Ferroeyanide of vanadium. — Salts of vanadic oxide gfive pale yellow, and ofvanamc
acid, rich green precipitates with prussiate of potash.
Ferroeyanide of yttrium. — Chloride of yttrium gives a white precipitate with ferro-
eyanide of potassium. , .
Ferroeyanide of^ zinc cannot be prepared by precipitation. It may be obtained n
the form of a white powder by the action of oxide or carbonate of sine on ferro-
prussic acid, — C. G. W. For Fbrro-Ctanooen, see Ure's Dictionary of CkesMtrf-
FIBRES, or FIBROUS BODIE& From time to time numerous grasies, fibroof
barks, and other substances of a similar character, have been introduced into com-
merce; a few of these only have been foand available for mannfactare. It is, howerer,
deemed of interest to describe briefly some of these. Some of the more inportaot
vegetable fibres will be folly noticed under their respective heads. (See Coib, Fux.
Hkmp, &c.) ,
China Grass. — This fibre is obtained from Urtica nivea, which grows »bundW
in China, and in various parts of our Indian empire. The samples which have be^
imported are principally obtained from Canton and Hong-Kong. In 1B49, ^^\^
Wright and Co. obtuned a patent for the preparation of this fibre. Their pro^
consisted essentially of boiling the stems in an alkaline solution, liter they ^i*^
previously steeped for 24 hours in cold water, and for 24 hours in water at 9(r t^
The fibre is then thoroughly washed with pure water, and finally subjected to ^
action of a current of high pressure steam till nearly dry. . .
CaUooee Hemp or Rhea. — This fibre is usually confounded with China 5J*** 1^- -J
there is little doubt they are obtained fh>m two different kinds of urtica. ^^t • ^
grass from the Urtica nivea of Willdenhow ; the Callooee Hemp, Kabnoi, or ^***V
Sumatra ; and the Bhea from the Urtica tenacissima of Roxburgh. The P^^^
ducing the Callooee hemp, was introduced from Bencoolen to Calcutta in ^^^^Z^i^
nnder the care of Dr. Roxburgh, it was for many years cultivated in the ^'J*" ^j
Gardens. In 1814, a quantity of the Callooee hemp was imported into ^^^"J^iftg
properly tested ; its practical value was thought so highly o^ that the Society ^^'
awarded a silver medal to Capt. James Cotton, of the East India Company, ^^^
FIBRES.
199
trodneed it '* The eluef obstacle which interfered, howerer, with its lue, wai the
difficulty which was found to exist in the preparation of the fibre fh>m the stems of
the plants ; none of the processes usually adopted with flax or hemp were Ibnnd to
be at all suitable to them ; and the rude, wasteful, and imperfect means employed by
the natlTes in preparing the fibre for the manufacture of twine, thread, and fishing
nets, by the mere process of scraping, were wholly inapplicable on a large scale,
and gave besides only a Tery inferior result. When macerated or retted in water, it
was found that the fibre itself was more easily destroyed than the glutinous matter of
the stem. During the last forty years, ▼arious attempts hare been made to devise a
good and cheap process for preparing this fibre, but hitherto without mueh success ;
and consequently, till quite recently, the cost of the fibre was such as to preclude its
being broi^t into the market as a substitute for flax. But recent iuTestigations have
shown that the Urtica tenacissima and the heterophyOa may be obtained in almost un-
limited quantities in Tarious parts of India ; and a process which has been lately
patented appears, to a very great extent, to have removed the practical difficulties
which previously stood in the way of its employment by manuihcturers ; so that in a
few years it is probable that the Callooee hemp will constitute an important addition to
the fibrous materials employed in the arts." — Juno's BeporU Great Exhibition^ 1851.
Neilgherry Nettle ( Urtiea heterophyUa), — This nettle appears to be remarkable beyond
all others for its stinging properties. It is abundant in Mysore, flourishing in Alpine
jungles. The Todawars prepare the fibre of this plant by boiling the stems In water,
after which they readily separate it Arom the woody parts and then spin it into a
coarse but very strong fibre. The Malays simply steep the stems in water fbr ten or
twelve days, after wUch they are so much softened that the outer fibrous portion is
easiW peeled off.
yircum Nar, — This is the native name of the fibres of the CaJoiropis (^AscUpias)
gigetnteoj a plant which grows wild, abundantly, in various parts of the Bengal and
Madras presidencies, and is used by the natives in the manufacture of cord called
" LamMore,** or '• T<mdee OnrP
Aloe fibre^ or Nar^ the produce of the Agave vivipcura, and other allied species.
This is often called the ** Silk grass fibre.'*
Pine-apple fibre, sometimes called ** Ananas JIcuf," This has been prepared in Java,
and at Travancore. Many fine specimens have been brought to this country.
Plantain fibre. — In the Government establishments of Ceylon this is extensively
employed. Canvass and ropes are made of it It is obtained fix>m the Musa textilis.
It is calculated that 8 cwt per acre of this excellent fibre might be obtained.
Mahant bark. — Employed at St Vincent's in the manufacture of fishing nets,
common cord, and coarse lines for fishing.
New Orleans moss {TtUandsia usneoides), a substitute for horse hair as a stuffing
material for upholsterers. Sometimes the fibrous husk of the Indian com is used
for the same purpose, but it is more brittle than the moss.
Palm-tree fibre. These fibres are obtained from many varieties of the palm.
Grass fibre. Many of the grasses are now being used in the manufacture of paper,
and for other purposes.
The following tables by Dr. Roxburgh and Dr. Wright, afibrd much information
as to the relative strengths of different kinds of fibrous substances. The first table
giTes experiments made by Dr. Roxburgh in 1804; some of the fibres were, however,
probably imperfectly prepared.
Commoii Name.
Botanical Name.
Breaking Weight.
1. Hemp (English^
2. Murga (Sfmseviera)
3. Aloe ....
4. Ejoo ....
5. Donsha • . . -
6. Coir ... -
7. Hemp (Indian)
8. Wo<^et comal
9. ? - . - -
la Sunn ....
11. Bunghi paat ...
12. Ghtt nala paat -
13. ?-
14. Flax (Indian)-
Cannabis sativa ...
Alectris nervosa ...
Agave Americana f -
Saguerus HumpJm ...
JEschynomone cannabina -
Cocos nuci/era - - -
Cannabis sativa ...
Abroma Augusta ...
Banhinia ....
Crotoiaria juncea ...
Corchorus olitorius ...
„ capsularis
Hibiscus mainhot ...
Linum usitatissimum
lbs.
105
120
110
96
88
87
74
74
69
68
68
67
61
39
„.
o4
200
FIBRrNR
In 1808, Dr. Roxburgh made another series of experiments, of which the foUowiog
table gives the result : —
Common Name.
Botanical Name.
Breaiing Wei|hL
1. Bowstring hemp
2. Callooee hemp
8. ?-
4. Sunn - - - -
5. Hemp (Indian)
6. Doncha ....
7. ?- - - -
8. Miista paat ...
9. Bunghi paat ...
10. Plantain- ...
AtcUpiag Sp, ....
Urtica tenacusima ...
Corchonu eapsularia
Crotolaria jvncea ...
Catmabis aativa ...
jEachynomone cannabina -
Hibiscus sb-ictus ...
„ canm^inus
Corchorus olitorius ...
Musa . . - « -
Ito.
248
240
164
160
158
138
128
115
lis
79
Experiments were made not long since by Dr. Wright on several well known up-
table fibres when made into ropes. The following were the results : —
Common. Name.
Botanical Name.
BreakiBK Vfti^i
1. Yercum nar ...
Calotropis gigatUea ...
552
2. Janapum ...
Crotolaria juncea ...
407
3. Cutthalay nar ...
Agave Americana ...
362
4. Cotton . - . -
Gossypium herbaeeum
a46
5. Maroot ....
Sanseviera zeykmica
316
6. Pooley mungu
HibiscuM cantuUfinus
290
7. Coir ....
Cocos nuci/era ...
224
The defect of all these fibres is, as it regards their use in weaving, that they breik
at the knot, and in all weaving processes the fibres require frequent joining.
Of vegetable substances of the nature and quality of undressed hemp we ia^aied
in 1857, from
Cwt. Computed real taloflL
Spain - - - . . . 7,250 . £ 8,997
Mexico 12,301 - 14,753
British East Indies .... 5,498 . 6,899
Other parts 2,309 - 2,918
27,358 £33,567
The peculiarities of these fibres are not specified, but as they are not hemp, to
tow, or jute, we may fairly infer that many of the fibres named above are included
in these importations.
FIBRE, VEGETABLE, called also Lignine (Liffneux, Fr. ; PJlanzenfeuentof,
Germ.) ; is the most abundant and general ingredient of plants, existing in all their
parts, the root, the leaves, the stem, the flowers, and the fruit ; amounting in the com*
pact wood to 97 or 98 per cent. It is obtained in a pure state by treating saw-diut
successively with hot alcohol, water, dilute muriatic acid, and weak potash lye, which,
dissolve, first, the resinous ; second, the extractive and saline matters ; third, the ctr-
bonate and phosphate of lime ; and, lastly, any residuary substances. Ligneous
fibres, such as saw-dust, powdered barks, straw, hemp, fiax, Imen, and cotton cloth, are
convertible by the action of strong sulphuric acid into a gummy substance analogous
to dextrine, and a sugar resembling that of the grape.
Much attention has, of late years, been directed to the conversion of vegetable fihre
into paper. See Paper.
FIBRINE (Eng. and Fr. ; Thierischer Faserstoff, Germ.) constitutes the princip
part of animal muscle ; it exists in the chyle, the blood, and may be regarded tf toe
most abundant constituent of animal bodies. It may be obtained in a pure state br
agitating or beating new drawn blood with a bundle of twigs, when it will attach itwu
to them in long reddish filaments, which may be deprived of colour by working them
with the han£i under a streamlet of cold water, and aiterwards freed from any ad-
hering grease by digestion in alcohol or ether.
Fibrine, thus obtained, is solid, white, flexible, slightly elastic, insipid, inodoroos*
dionser than water, but containing 4 fifths of its weight of it, and without action o&
FILE. 201
litmiu. When dried, it becomes semi-transparent, yelloirish, stiff, and brittle : water
restores its softness and flexibilitj. 100 parts of fibrins consist of 53*36 carbon, 19*68
oxygen, 7'OS hydrogen, and 1931 aiote. As the basis of fiesh, it is a rery nutritions
snbstance, and is essential to the sustenance of camivorons animals.
FICTILE MANUFACTURE. See PoirnBT, &c
FILE (Xune, Fr.; FdU^ Germ.) is a well known steel instrument, haying teeth
npon the surface for cutting and abrading metal, ivory, wood, &c.
When the teeth of these instruments are formed by a straight sharp-edged chisel,
extending across the sorfiK^e, they are properly caUed files ; but when by a sharp-
pointed tool, in the form of a triangular pyramid, they are termed rasps. The former
are need for all the metals, as well as ivory, bone, horn, and wood ; the latter for
wood and horn.
Files are divided into two varieties, ftom the form of their teeth. When the teeth
are a series of sharp edges, raised by the flat chisel, appearing like parallel furrows,
either at right angles to the length of the file, or in an oblique direction, they are
termed aingle cut But when these teeth are crossed by a second series of similar
teeth, they are said to be doubte cut. The first are fitted for brass and copper, and
are found to answer better when the teeth run in an oblique direction. The latter
are suited for the harder metals, such as cast and wrought iron and steel. Such teeth
present sharp angles to the substance, which penetrate it, while single cut files would
slip over the surface of these metals. The double cut file is less fit for filing brass
and copper, because its teeth would be very liable to become clogged with the filings.
Files are also called by different names according to their various degrees of
fineness. Those of extreme roughness are called rough ; the next to this is the
bastard cut ; the third is the second cut ; the fourth, the smooth ; and the finest
of all, the dead smooth. The very heavy square files used for heavy smith- work
arc sometimes a little coarser than the rough $ they are known by the name of
rubbers.
Flies are also distinguished from their shape, as fiat, half-round, three-square, four-
square, and round. The first are sometimes of uniform bresdth and thickness
thronghont, and sometimes tapering. The cross section is a parallelogram. The
half-round is generally tapering, one side bein^ flat, and the other rounded. The
cross section is a segment of a circle varying a little for different purposes, but seldom
equal to a semicircle. The three-square generally consist of three equal sides, being
equilateral prisms, mostly tapering ; those which are not tapering are used for sharp-
ening the teeth of saws. The four-square has four equsl sides, the section being a
square. These files are generally thickest in the middle, as is the case with the
smith's rubber. In the round file the section is a circle, and the file generally
conical
The heavier and coarser kinds of files are made ftom the inferior marks of blistered
BteeL Those made Arom the Russian iron, known by the name of old sable, called
from its mark CCND, are excellent The steel made from the best Swedish iron,
called Hoop L or Dannemora, makes the finest Lancashire files for watch and clock
The steel intended for files is more highly converted thsn for other purposes, to give
them proper hardness. It should however be recollected, that if the hardness be not
accompanied with a certain degree of tenacity, the teeth of the file break, and do but
little senrioe.
Small files are mostly made of cast steel, which would be the best for all others, if
it were not for its higher price. It is much harder than the blistered steel, and fVom
having been in the fluid state, is entirely free from those seams and loose parts so com-
mon to blistered steel, which is no sounder than as it comes from the iron forge before
conversion.
The smith's rubbers are generally forged in the common smith*s forge, from
the converted bars, which are, for convenience, made square in the iron before they
come into this country. The files of lesser size are made from bars or rods, drawn
down from the blistered bars, and the cast ingots, and known by the name of tilted
steel.
The file-maker's forge consists of large bellows, with coke as fhel. The anvil-
block, particularly at Sheffield, is one large mass of mill-stone grit The anvil is of
considerable size, set into and wedged fast into the stone ; and has a projection at one
end, with a hole to contain a sharp-edged tool for cutting the files from the rods. It
also contains a deep groove for containing dies or bosses, for giving particular forms
to the files.
The flat and square files are formed entirely by the hammer. One man holds the
hot bar, and strikes with a small hammer. Another stands before the snvil with a
two-handed hammer. The latter is generally very heavy, with a broad face for the
202 FILR
large filei. Thsy loth ■triko with mch tmih u to make the lurhee mMl] nl
flat, wilhoat what ii called hand-hsmmeriDg. Thii arise* frnm their gT«U eipcnns
ID die lame kind of work. The eipeditioo aiiiiag from the laiiie cuiuIiiki(Ib
remarkable.
The half-rooDd file* are made in a bou Ikftencd into the grooTe abcm maitaL
The Meel beiog drawn ont, i> lud apon the rounded reced, and hammered till it Gli
the die.
The tbree-iided fl1« are formed limilarl; io a boo, the receu of which coana rf
two sidei, with the angle downwanll. The iteel ii SiM drawn ont iqQut, anil l^
placed in a boas with an angle downwards, so that the hammer formi oae odt. ud
the bofii two. The round files are formed bj a swage uinilar to ihow iwd tij
common imitha, but a little conicoL
The file cutter reqoirti an aDvii of a die greater or leas, proportioned to dw ait of
hii files, with a face as ereu and fiat as possible. The hammers weigh (nm at u
fire or iie ponods. The chisels are a little broader than the file, ghvpcHd lo a
angle of about SO degrees. The length is jnat snffidcnt for them to be beldfiBlK-
tween the finger and thamb, and so strong as not to bend with the strnkts of ili
hammer, the inCeniitj of which may be best couceiTed by the depth of the iBi;nBii&
The anVil is placed in the jhce of a Mnmg wooden post, to which a woodea ksI i> u-
tached, at a small distance below the level of the anvil's &ce. The file ii &it lui
upon the bare anvil, oae end prDjecting over the front, and the other over ibe tack
edge of the same. A leather strap now goes over each end of the file, ud piwi
down upon each side of the block to thevorkmsn's feet, which, being put intilbanp
on each side, like a stirrap, holds the file firmly upon the anvil as it is cat. Wliili in
point of the file is catting, the strap passes over oae part of the file only, tht pa
resting upon the aovil, and the tang apon a prop on the other side of the Unp. "^^
one side of the file ia single cut, a fine file is run slightly over the teeth, to take lOf
the roughness ; when Itaey are to be double cat, another set of teeth i< cat, amn
the former nearly at right angles. The file is now finished upon one aide, anl il ■
evident that the cat side cannot be laid upon the hare anvil to cut the other, A da
piece (rf'Bn alloy of lead and tin ia interpoied between the toothed sorfue udUi
anvil, while the other side is cut, which completely preserves the side alrtadj Irrati
Similar pieces of lead and tin, with angular and rounded grooves, are Bsed br miint
triangular and half-round files.
Rasps are cat precisely in the aame way, by using a triangalar paneb iosuao ■■ ■
flat chisel The great art in cutting a rasp is to pSue every new tooth as mntn »
possible opposite to a vacancy. .
File cutting machines have been from time to time invented, to '^'^^\^
Montigny re^ a memoir before the Committee of Commerce, in which he ^'^"^
the inventions for file-cutling in 1699 by Dnverger, in I7S.1 by Fordoort, la U"
by Thiout, in 1756 by Brachat and Gamain, and in 17?8i since which, i" 1*"^ ^
invented a file-cottiug machine] and in 1836 Ericsson introduced another, '"j^
Bobison, juat before his death, invented a method for cutting curved file* I "^ "
1B43, Messrs. Johnson, Cammell, and Co. received the medal of the Scottish SofidJ
of Arts for perftctiug Sir J. Robison's acheme. The accompanying •""r.'^
which are representationa of the file-cntting machine of Mr. W. Shilton of Bumiiigl^
wiU ahow the general pM^
uponwhlch thoae machmea M* ""■
atmcced.
Ia order to render thiJ '"^"f
better understood, two vie« <*«'
appanitua for producing the '"^
cut or teeth of the file*. »" P],~^,
Fig. 7*9 is an elevBdca « «
upper part of the fil^"«^^
chine, as seen on one ude i J^ '"
U a plan or horisontal vi(», " *
machine appears on the tep.
a, ia the head of the till twn"
placed in the end of lb" '"f *
which ia moonted on "n ^^
turning in proper bwrinP/j,^
frame work of the machio* ^ * " ^
tilt wheel mounted on MOtW"
s. also lumiog in i^^P "1^
frame work of the machine, and having any required nimiber of prqjectiooi " "r
pets upon it for depressing the tail <a ahoner end of the hammer st tilt I**"
FILE. 203
The tilt vheol J, lecriTw iu rotUorj iDotion from tli« tootbed wheel j^ noanted
npoD the Hme utle, and it laket into guar with t, pimioD g, npoD the mtia iluft A,
which ia (ctoated b; a band paued
frotn any Srst mover to the tif^er "*°
OD its eiid, or in any other codtc-
nicDt maiuier. The bed upon which
the blank piece of sleel bean ia E
marked L Thii bed ii Bnnl; lap- 1
ported Dpon matonrf placed apoa
proper ileeperv - j, ia one of the
bkank pieoea of Iteel mider opeta-
tion, udisehowDiecnrediDthepair
ofjawaoT holding clampa k, mounted
cm ceolre pirn in the slide L,fig. 7S0, I
which tlide ia held dowo by a iprioK
and alide beneath, and ii moTed
backward* and forward* \a the ma-
chine opoD the (v) edges pi m, of
the fraioe, bj mcana of the rack a
and ita pinion; the latter being
loonnted uponlbe axle of the ratchet
wheel p, and which ratchet wheel
ji made to tarn al iDlerrali by metuu of the pall g, npon the end of the lever r,
fig. 750. Thiileier i« depresM>d, after every cut has been effected upon the blank bj
meana of the teeth or tappets of the wheel *, comiajt in contact with Uie inclined plane
t, upon the lever r. The tappet wheel t, ia mounted npon tbe end of the axle e, of
the tilt wheel, and eonaeqaentlj revolvec with it, and by depreMiog the lever r, eiery
time (hat a tooth paue* the inclined plane t, the click q, it made tn drive the ratchet
wheel ^, and thereby the adTftncing morement of the blank is effected after each
blow of the lilt hammer.
There ii a itrong spring k, attached to the apper side of the till hammer, its end
being confined nnder an adjostible inclined plane i>, moanled in the ftame lo. which
inclined plane can be raised or lowered by iu adjusting screw* ni required, to pro-
dooe more or leu teniion of the spring.
A similar spring ia placed on the under side of the tilt hammer, to r«i*e and lastain
ihe cntter or tool clear i^tbe bed aAer every blow, and in conjonclioD with lajety
holdera or catchen, to counteract any vibration or tendency the spring h, may have
to canse the hammer to reiterate the blow.
Tbe end of the lower spring acts on an inclined plane, mounted in the frame »,
which hai an adjusting screw similar to u, to regulate the lenaion of the spring.
In eaae the onder tpring shanld raise, that is, return the hammer, with sufficient
force or velocity lo caose the top spring u, to reiterate the blow, the ends of the safety
balden or catcben are made to move under and catch tbe tail of the lever b, immedi-
ately on it* b«ing raised by the under springs, which i* effected by the following
meaoi: — The holders are mounted upon a plate or carriage 1, Jig 749, which turn*
npoa a small pin or axle mountrd in the ear* of a cross bar ; the upper end* of the
hidden are kept inclined toward* tbe tail of (be tilt hammer by means of a spring
fixed to theeroM bar, and which act* upon one end of the plate or carriage.
In order that tbe holders may be removed out of the way of the tail of the hammer
h, when the tilt wheel i* about to effect a blow, tbe tooth of tbe tilt wheel which
last acted upon Ihe hammer comes in contact with an inclined plane fixed on
tbe plate or carriage t, and by deprening that end of tbe plate, causes the upper
ends of Ihe holders to be withdrawn from nnder the tail of the hammer h. The
tilt wheel continuing lo revolve, the next tooth adviutces, and depresses the tail of tbe
hammer, but before it leavei tbe tail of the hammer, tbe tooth last in operation will
have quitted tbe inclined plane and aUowed the spring to return the holden into their
Canncr pOBlion. After the tooth has escaped from the tail of i, the hammer will im-
mediately descend and effect the blow or cut on the blank, and as the tul of the
hammer riaea, it will come in contact with tbe inclined planes at the upper ends of the
holders, and force them backward* ; and as soon a* tbe tail of the hammer hag passed
tbe lop of the holders, Ihe spring will immediately force the holders forward under
the tail of the hammer, aod prevent tbe bammer rising again until the next tooth
of the tilt wheel i* aboot lo depress the end of tbe h^imer, when the ume move-
ments of the parts will be repeated, and the machine will continue in operation until
a anffleient length of the blank of sleel (progresuvcly advanced under tbe bi
baa been operated npon, when it will be thrown ont of ge~
204 FILE.
most end of the slide / Ufig. 750, Ot^mes in contact as it is moTed forward bj the nek
n, and its pinion. The sliding bar 6, is connected at its left end to the bat lever 8,
the other end of this lever being formed into a forked arm, which embraces t clmeh
npon the main shaft, and as the slide / continues to advance, it will come in oootirt
with a stop ; and when it has brought a sufficient length of the blank pieces of steel
under the operation of the cutting tool, the slide /, in its progress, will hate mored
that stop and the bar 6 forward* and that bar, by means of the bent lever 8,iri0 vitli-
draw the clutch on the main shaft, from locking into the boss of the fly-vbeel, tod
consequently stop the further progress of the machine ; the rigger and fl/'vhed
turning loosely upon the main shaft.
The cut file can now be removed from out of the clamps, and rerened toeottlK
other side, or another blank piece put in its place ; and after throwing bsck the pill
^ of the ratchet wheel p, the slide i, and with it the ft^sh blank, may be moTed bick
into the machine by turning the winch handle, on the axle of the ratohet wheel ^ the
reverse way, which will turn the pinion backwards, and draw back the rack n, vithoot
affecting any other parts of the machine ; and on moving back the bar 6, bj the
handle 11, placed on the stop, the clutches will be thrown into gear agsiSjUdtke
machine proceed to cut the next blank.
When the blanks have been thus cut on one side, and are reversed in tbe BuehiBe
to form the teeth upon the other side, there should be a piece of lead placed betvecntbe
blank and the bed to protect the fresh cut teeth.
It will be seen that the position of the stop upon the bar 6, will detarmiiM tix
length or extent of the blank piece of steel which shall be cut or operated npoa; ind
in order that the progressive movement of the blanks under the cutting tool mtr be
made to suit different degrees of fineness or coarseness of the teeth (that is thedtf-
tance between the cuts), there is an a^josting screw upon the lever r, the heid d
which screw stops against the under side of an ear projecting from, the fnofi-^oii
and thereby determines the extent of the motion of the lever r, when depreoed by
the tappets of the wheel «, acting upon the inclined plane t, consequently detennnuBg
the number of teeth the ratchet wheel p shall be moved round by the pall f ; u»
hence the extent of motion conmiunicated by the rack and pinion to the slide I vA
the blank J, which regulates the distance that the teeth of the file are apart, and tbe
lever r is forced upwards by a spring pressing against its nnder side.
It will be perceived that the velocity of the descent of the hammer, and consh
qnently the force of the blow, may be regulated by raising or lowering the i"^'"?^
plane v of the spring u ; and in order to accommodate the bed upon which thewBw
rest to the different inclinations they may be placed at, the part of the bed is wnaA
of a semi-globular piece of hardened steel, which fits loosely into a similar c^j'!^
similar shaped concavity. .
There are guides 16, placed on the top of the bed i, for the purpose ^^^^^^^
blanks in their proper position towards the cutting tool, and these cos be ']^^t*v
to suit blanks of any width, by turning the right and left handed screw 17. ."^"^
also another a^justible stop on the jaws or clamps k which serves as a gsi^' ^"^
placing the blanks within the jaws : and 19 is a handle or lever for raising the cUDp
when required, which has a weight suspended ftx>m it for the purpose of heepingdo
the blanks with sufficient pressure upon the bed. . ^
The cutting tool in the face of the hammer, can be placed at any required *^,
inclination with the blank, it being secured in the head of the hammer by ^^P'^J
screws. In cutting fine files a screw is employed in preference to the n^
pinion, for advancmg the slide /, and the blank piece of steel in the machine.
Hardening the files, ^This is the last and most important part of file "Jr'j
Whatever may be the quality of the steel, or however excellent the workio«n*"P'
it is not well hardened all the labour is lost «. ^
Three things are strictly to be observed in hardening ; first, to prepare the nw
the surface, so as to prevent it from being oxidated by the atmosphere *ben
file is red hot, which effect would not only take off the sharpness of the ^^^^^
render the whole surface so rough that the file would, in a little time, bec^
clogged with the substance it had to work, Secondly, the heat ought ^^^
uniformly red throughout, and the water in which it is quenched, fresh «"° JJ^
for the purpose of giving it the proper degree of hardness. Lastly, ^^^.^^
immersion is of great importance, to prevent the files firom warping, ^^'^ "
thin files is very difficult . i^
The first object is accomplished by laying a substance upon the fil^i ^^^iLTde
it fuses, forms as it were, a ^Amish ii|H>n tiie surface, defending the metal from
FILE. 205
action of the oxygen of the air. Fonnerly the process cousisted in first coating the
snrfaoe of the file with ale groonds, and then covering it over with pulverised common
salt (mariate of soda). After this coating became dry, the files were heated red hot,
and hardened ; after this, the surface was lightly brushed over with the dnst of cokes,
when it appear white and metallic, as if it had not been heated. This process has
lately been improved, at least so fkr as relates to the economy of the salt, which from
the qoantity used, and the increased thickness, had become a serious object Those
who nsed the improved method are now consuming about one fourth the quantity of
salt used in the old method. The process consists in dissolving the salt in water
to satnmtion, which is about three pounds to the gallon, and stiffening it with ale
grounds, or with the cheapest kind of fionr, such as that of beans, to about the con-
sistence of thick cream. The files required to be dipped only into this substance, and
immediately heated and hardened. The grounds or the flour are of no other use,
than to pve the mass consistence, and by that means to allow a larger quantity of
salt to be laid upon the surface. In this method, the salt forms immediately a firm
coating. As soon as the water is evaporated, the whole of it becomes fused upon the
file. In the old method the dry salt was so loosely attached to the file, that the
greatest part of it was nibbed off into the fire, and was sublimed up the chimney,
withoat producing any effect.
The carbonaceous matter of the ale grounds is supposed to have some effect in give
ing hardness to the file, by combining with the steel, and rendering it more highly
carbonated. It will be found, however, upon experiment, that vegetable carbon does
not combine with iron, with suiBcient &cility to produce any effect, in the short space
of time a file is heating for the purpose of hardening. Some file makers are in the
habit of using the coal of burnt leather, which doubtless produces some effect ; but
the carbon is generally so ill prepared for the purpose, and the time of its operation
so short, as to render the result inconsiderable. Animal carbon, when properly pre*
pared and mixed with the above hardening composition, is capable of giving hardness
to the suirface even of an iron file.
This carbonaceous matter may be readily obtained from any of the soft parts of
animals, or from blood. For Uiis purpose, however, the refuse of shoemakers and
curriers is the most convenient After the volatile parts have been distilled over,
from ao iron still, a bright shining coal is left behind, which, when reduced to powder,
is fit to mix with the salt Let about equal parts, by bulk, of this powder, and
muriate of soda be ground together, and brought to the consistence of cream, by the
addition of water. Or mix the powdered carbon with a saturated solution of the salt,
till it become of the above consistence. Files which are intended to be very hard,
should be covered with this composition, previous to hardening. All files intended
to file iron or steel, parlicularly sa^ files, should be hardened with the aid of this
mixture, in preference to that with the flour or grounds. Indeed, it is probable, that
the carbonaceous powder might be used by itself, in point of economy, since the
ammonia or hartshorn, obtained by distillation, would be of such value as to render
the coal of no expense. By means of this method the files made of iron, which in it-
self^ is unsusceptible of hardening, acquired a superficial hardness sufficient for any
file whatever. Such fifes may, at the same time, be bent into any form ; and, in con-
sequence, are particularly iwefkil for sculptors and die-sinkers.
The next point to be considered is tbe best method of heating the file for hard-
ening. For this pntpose a fire, similar to the common smith's fire, is generally
employed. The file Is hold in a pair of tongues by the tang, and introduced into
the fire, consisting of very small cokes, pushing it more or less into the fire for
the purpose of heating it regularly. It must frequently be withdrawn with a view
of observing that it is not too hot in any part When it is uniformly heated, from
the tang to the point of a cherry red colour, it is fit to quench in the water. At
present an oven, formed of fire-bricks, is used for the larger files, into which the
blast of the bellows is directed, being open at one end, for the purpose of introduc-
ing the files and the fuel Near to the top of the oven are placed two cross bars,
on which a few files are placed, to be partially heating. In the hardening of heavy
files, this contrivance affords a considerable saving, in point of time, while it permits
them also to be more uniformly and thoroughly heated.
After the file is properly heated for the purpose of hardening, in order to produce
the greatest possible hardness, it should be cooled as soon as possible. The most
common meUiod of effecting this is by quenching it in the coldest water. Some file-
makers have been in the habit of putting different substances in their water, with a
view to increase its hardening property. The addition of sulphuric flcid to the water
was long held a great secret in the hardening of saw files. After all, however, it will
be found, that clear spring water, free ttom animal and vegetable matter, and as cold
as possible, is the best calculated for hardening files of every description.
206
FILTRATION.
In qnenchiDg the files in vater, some caution most be observed. AU files, except the
half-round, should be immersed perpendicularly, as quickly as possible, so that the
upper part shall not cool. This management prevents the file from -warping. The
half-round file must be quenched in the same steady manner ; but, at the same time
that it is kept perpendicular to the surface of the water, it must be moved a Jittle
horizontally, in the direction of the round side, otherwise it will become crooked
backwards.
After the files are hardened, they are brushed over with water, and powdered cokes^
when the surface becomes perfectly clean and metallic, They ought also to be washed
well in two or three clean waters for the purpose of carrying off ^ the salt, whidi. if
allowed to remain, will be liable to rust the file. They should moreoTcr be dipped
into lime-water, and rapidly dried before the fire, after being oiled with olive oil,
containing a little oil of tarpentine, while still warm. They are then finished.
FILLIGREE {FiUgrane, Fr. ; Filigran, or Peine Drahtg^echt, Germ.) is, as tke
last term justly expresses it, intertwisted fine wire, used for ornamenting gold and silver
trinkets. The wire is seldom drawn round, but generally flat or angular ; and soU
dered by gold or silver solder with borax and the blowpipe. Hie Italian word,
filigranoy is compounded of filum and granum, or granular net*work ; becanse the
Italians, who first introduced this style of work, placed small beads upon it.
FILTRA.TION (Eng. and Fr.; Filtnren, Germ.) is a process purely mechaniei],
for separating a liquid from the undissolved particles floating in it, which liquid may
be either the usefiU part, as in vegetable infusions, or of no use, as the washings of
mineral precipitates. The filtering substance may consist of any porous matter in a
solid, foliated, or pulverulent form ; as porous earthenware, unsized paper, cloth of
many kinds, or sand. The white blotting paper sold by the stationers answen ex-
tremely well for filters in chemical experiments, provided it be previously washed with
dilute muriatic acid, to remove some lime and iron that are generally present in it
Filter papers are first cut square, and then folded twice diagonally into the sliape of a
comet, having the angular parts rounded off. Or the piece of paper being cut into a
circle, may be folded fan-like from the centre, with the folds placed exteriorly, aad
turned out sharp bv the pressure of the finger and thumb, to keep intervals betwen
the paper and the funnel into which it is fitted, to favour the percolation. The diameter
of the fiinnel should be about three-fourths of its height, measured from the neck to
the edge. If it be more divergent, the slope will be too small for the ready eflinx of
the fiuid. A filter covered with the sediment is most conveniently washed by spootiag
water upon it with a little syringe. A small camel's-hair paint brush is much employed
for collecting and turning over the contents in their soft state. Agitation or vibration
is of singular efficacy in quickening percolation, as it displaces Sie particles of the
moistened powders, and opens up the pores which had become dosed. lostesid of a
funnel, a cylindrical vessel may be employed, having its perforated bottom covered
with a disc of filtering paper folded up at the edges, and made tight there by a wire
ring. Linen or calico is used for weak alkaline liquors ; and fiannels, twilled woollen
cloth, or felt- stuff for weak acid ones. These filter bags are often made conical like a
fool's cap, and have their mouths supported by a wooden
or metallic hoop. Cotton wool put loose into the neck d
a funnel answers well for filtering oils upon the small
scale. In the large way, oil is filtered in conical woollen
bags, or in a cask with many conical tubes in its bottom,
filled with tow or cotton wool. Stronger acid and alkaline
liquors must be filtered through a layer of pounded glass,
quartz, clean sand, or bruised charcoal. The alcarrhazas
are a porous biscuit of stone ware nuule in Spain, which
are convenient for filtering water, as also the poroos filtering
stone of Teneriffe, largely imported into England at one
time, but now superseded in a great measure by the arti-
ficial filters patented under many forms, consisting e
tially of strata of gravel, sand, and charcoal powder.
It is convenient to render the filter self-acting, by
modating the supply of liquid to the rate of percolation, so
that the pressure upon the porous surface may be always
equally great. Upon the small scale, the lamp-fountain or
bird's-glass form so generally used for lamps, will be foond
to answer.
Fig, 751, represents a glass bottle A, partly filled with
the fluid to be filtered, supported in the ring of a chemical
stand, and having its mo th inverted into the same liquor in the filter funnel. It is
obvious, that whenever this liquor by filtration falls below the lip of the bottle, air
FILTRATION
207
viU eDter into it, let down ■ tretii tapf[j to feed th« filter, and keep the (UddgI re-
golaiij charged, [f larger qnaatilieB are to he operated apon, the foIJowiug appa-
i>uu intLj he employed. Fig- T53, A k, ii a metallic -j^g
*ei»el which nuj be made aii^tigbt ; c is the under
pipe provided with a atopeock b, for letliDR doiro
the liquor into the filter a b. Tbe upper pipe t, through
which the flnid ia pooled \>j mean* of the fanuel k,
has alMi a ttopcock which opeag or thata, at the ume
time, the bhuU aide tulie h t, thr(iu);h which, during
the entrance of the flaid, the air is let off tmrn the
receiTcr. A glass tnbe g, shows the level of the
liquor in the bod^ of the apparatus. In using it, the
cock R most be first closed, and the cock a must be
opened to fill the receiver. Then the filler ia set a
going, by re-openlng tbe cock k, to as to keep the fluid
in the filler upon a level with the opening of the lubeo.
Both these piecea of apparatus are essentially the same.
In man; msnnfiiclurei, self-acting filters are fed by
tbe plumber's common contrivance of a ball-cock in
which the sinking and riling of the ball, within certain
limits, serves to open or ghat off the supply of liqaor
aa it may be required or not l>umont hu adopted
this expedient for his system of filtering sj-rup through
& Btralum of granularly ground animal charcoal or i
bone-black. F\g. 7 S3, ia a front view of this apparatns
with 4 filters c ; and fig. 7S1 is a cross section. The
fhuDcvork a supports the cistern A, in which the Sfrup
is contained. Prom it the liquor flows through tbe
■top-cock b, and the coonectioD-tQbe a, into the coninon
pipe r, which communicates, by the abort branch tubes t, with each of the fonrfillera.
The end of the branch tube, which ia inside of tbe filler tub, is provided with a stop-
XK^ d/, whose opening, and thereby the efflux of the liquor from the cistern thraagh
the UiIh- a, is regulated bj meana of the floating-baU g. Upon the brickwork D the
filler tub stands, fttraished at A j^^
with a blse bottom of line or
eopprr pierced with fine holes ; be-
sides which, higher cp at i there is
another such plate of metal fnr-
Dubed wiih a strong handle A, by
which it may be removed, when tbe
bone-black needa to be changed.
In the intervening spai^e I, the
rrranolar coal is placed, o in tbe
coTcr of the filter tnb, with a
hanille also for lifting it One por-
tion of it may be niacd by a hinge,
when it la desired to inspect the
pn^resa of ihe filtration within.
■ M is a slender vertical tube, forming a commauication between the bottom part h,
and the upper portion of the filter, to admit of the eiL^y escape of the air from that
apace, and from among tbe bone-blacL as the sjrup descends ; otherwiac tbe filtration
208 FILTBATION.
could Bot go on. p \s the stopcock through which the fioid collected in the
space under k is let off from time to time into the common pipe 9, fig. 753. r b
a trickling channel or groove lying parallel to the tube q, and in which, by means
of a tube «, inserted at pleasure, the syrup is drawn off in case of its flowing in a
turbid state, when it must be returned over the surface of the charcoaL
The celerity with which any fluid passes through the filter depends, — 1, upon the
porosity of the filtering substance ; 2, upon the pressure exercised upon it ; and 3, upon
the extent of the filtering surface. Fine powders in a liquor somewhat glutinous, or
closely compacted, admit of much slower filtration than those which are coarse and
free ; and the former ought, therefore, to be spread in a thinner stratum and over a
more extensive surface than the latter, for equal effect ; a principle well exemplified in
the working of Dumont's apparatus, just described.
In many cases filtration may be accelerated by the increase of hydrostatic or pneu-
matic pressure. This happens when we close the top of a filtering cylinder, and con-
nect it by a pipe with a cistern of fluid placed upon a higher level. The pressure of the
air may be rendered operative also either by withdrawing it partially from a dose
vessel, into which the bottom of the filter enters, or by increasing its density over the
top of the liquor to be filtered. Either the air pump or steam may be employed to
create a partial void in the receiver beneath the filter. In like manner, a forcing pump
or steam may be employed to exert pressure upon the surface of the filtering liquor. A
common siphon may, on the same principle, be made a good pressure filter, by making
its upper leg trumpet-shaped, covering the orifice with filter paper or cloth, and filling
the whole with liquor, the lower leg being of such length so as to create considenbte
pressure by the difference of hydrostatic level. This apparatus is very convenient
either on the small or great scale, for filtering off a clear fluid from a light muddy
sediment The pressure of the atmosphere may be elegantly applied to commcm filtcn,
by the apparatus represented in^. 755, which is merely a funnel enclosed within a
^ gasometer. The case ▲ b bears an annular hollow vessel a h,
*^^ failed with water, in which receiver the cylindrical gasometer,
f d, e^f, I, is immersed. The filter funnel c is secured at its
r II upper edge to the inner surface of the annular vessel a 6. In
•'"I J" • consequence of the pressure of the gasometer regulated by the
weight g, upon the air inclosed within it, the liquid is equallj
pressed, and the water in the annular space rises to a corre-
sponding height on the outer surface of the gasometer, as shown
in the figure. Were the apparatus made of sheet iron, the an-
nular space might be charged with mercury.
In general, relatively to the application of pressure to filters,
it may be remarked, that it cannot be pushed very far, without
the chance of deranging the apparatus, or rendering the filtered
liquor muddy. The enlargement of the surfiice is, generally
speaking, the safest and most efficacious plan of increasing the
rapidity of filtration, especially for liquids of a glutinous nature. This expedient is
well illustrated in the creased bag filter now in use in most of the sugar refineries of
London. See Sugar.
In many cases it is convenient so to construct the filtering apparatus, as that the
liquid shall not descend, but mount by hydrostatic pressure. This method has two
advantages : 1. that without much expensive apparatus, any desired degree of hydro-
static pressure may be given, as also that the liquid may be forced up through several
filtering surfaces placed alongside of each other ; 2. that the object of filtering, which
is to separate the particles floating in the fluid without disturbing the sediment, may
be perfectly attained, and thus very foul liquids be cleared without greatly soiling the
flltering surface.
Such a construction is peculiarly applicable to the purification of water, either alone,
or combined with the downwards plan of filtration. Of the former variety an example
is shown in ^^. 756. The wooden or zinc conical vessel is provided with two per-
forated bottoms or sieves e e, betwixt which the filtering substance is packed. Over
this, for the formation of the space h A, there is a third shelf^ with a hole in its middle,
through which the tube d b is passed, so as to be water tight. This places the upper
open part of the apparatus in communication with the lowest space a. From the com-
partment A A a small air tube / runs upwards. The filtering substance consists at bottom
of pebbles in the middle of gravel, and at the top of fine sand, which may be mixed
with coarsely ground bone-black, or covered with a layer of the same. The water to
be filtered being poured into the cistern at top, fills through the tube b d the inferior
compartment a, from which the hydrostatic pressure forces the water upward through
the perforated shel^ and the filtering materi^s. The pure water collects in the space
h A, while the air escapes by the small tube /, as the liquid enters. The stopcock t serves
FILTRATION.
Id dra* off ihe filtered water. .
tides nxpendcd in it have time
orer the upper ihelf at d^ u
veil as orer the nader one at
a,sprecipilKte or deposit irhicb
nuj be wished out of the latter
caTity b/ meuu of the itop-
As ui example of an apwards
and dowDward* filter,^. ;S7
maj be exhibited, a b c v i*
a wooden or metallic ciateni,
famished with tbe perforated
>bclf e d aax its ander pan,
upon wbich a Tertical partition
is fixed tliroagb tbe axis of tbe
TMsel. A iemiciTcnlar perfo-
nted jhelf ii placed at a, and a
second iimilar one at &. These
horiiontBl sbelve* rest npon
brackets in the sides of the cincnu, lo that the; may be readil; \iftrd onC. The space
c is filled witb coarse sand, j with moderately fine, and H with very fine. The foul
water is poured into the chamber E, and presses through o J H and into the Bpac«r,
whence it maj be drawn bj the stopeock j^
Fig. TSS repreiails in section a filtering apparatoa eonsistiiig of two concentrio
chambers ; the interior being destined for downwards GltratioD, and tbe exterior for
upwards. Within the larger cistern ji, a amaller one b is placed conceDlricail}', witb
its under part, aod is left open from distance to distance, to make a oommnnicatiun
betwem the interior caTitj and tbe exterior annular space. These csTities are filled
to the marked height with sand and graveL The inner cjlindrical space has En«
sand below, then iharper sand with grannlsr charcoal, next coarse sand, aud lastly
graiel. The annular space bai in like manner fioe sand below. The foul water i*
introduced bj the pipe s, the ori&ce at whose end is acted upon h; a ball-coclc witb
TS8
its IcTer a ; whereh; tbe water is kept always at the same level in
Tbe water sinks through tbe sand strata of tbe middle leseel, pass<
the inner Tessel.
■,i through tbe sand strata of tbe middle leseel, passes oatwartts at its
Mmom into the anaular space, tbence np Ibroagh the sand in it, and collecting aboie
it, ia let off bj the stopcock on tbe pipe b. When a muddy deposit forms after some
time, it maj be easily cleared out The cord e, running over the pulleys//, being
drawD tight, the ball [ever will shot up tbe valre. Tbe stopcock d made fast to the
eoDdneting tnbe ■ must then be opened, so that the water now overflows into the
auDolar (pace at a ; the tube c, in communicatioii with Ihe inner space B, being opened
bj taking oat tbe stopper h. The water thereby percolates through the sand strata in
the reverse direction of its usual course, so as to clear away Ihe impurities in the
space B, and to discharge them by the pipe c h. An apparatus of this kind of
moderate size is capable of filtering a great body of water. It should be coo-
Etmeted for thai purpose of masonry ; but upon a small acale it may be made of
It apparalos for filtering oil upwards isrepreseuled in j!if. 799. ^isanoil
210 FILTRATION.
cask, in which the impure parts of the oil hare accamalated over the hottom. hDne-
diately above this, a pipe a is let in, which communicates with an elevated water ebteni
n. /is the filter (placed on the lid of the cask), furnished with two perforated sbelvo,
one at e and another at d; which divide the interior of the filter into three com-
partments. Into the lower space immediately over the shelf e, the tube 6, faniibed
with a stopcock enters, to establish a communication with the cask ; the middle esTitj
e is filled with coarsely ground charcoal or other filtering materials ; and the upper
one has an eduction pipe L When the stopcocks of the tubes a and h are opened, the
water passes from the cistern into the oil cask, occupies firom its density always tbe
lowest place, and presses the oil upwards, without mixing the two liquids ; wberebjfint
the upper and purer portion of the oil is forced through the tube b into tbe fiher, od
thence out through the pipe L When the fouler oil follows, it deposits its imporitiei
in the space under the partition c, which may from time to time be drawn off throogh
the stopcock k, while the purer oil is pressed upwards through the filter. Inthisvij*
the different strata of oil in the cask may be filtered off in succession, and kept lepante,
if found necessary for sale or use, without running any risk of mixing up the moddj
matter with what is clear. According to the height of the water cistern a, will be tbe
pressure, and of course the filtering force. When the filter gets choked irith dirt, it
may be easily re-charged with fresh materials.
it has been for many years the custom of the water companies to send the water taken
from the river through filter beds, prepared usually of sand and gravel It was Iobj;
thought that tbe effect of these filter beds was merely to separate the solid iofoIoNe
matters suspended in the water. It has, however, b^n shown by the investigation of
the late Mr. Henry M. Witt (a chemist of peculiar promise, lost too soon to science,
and ere yet the world could recognise his powers), that these filter beds had tbe pover
of separating many of the dissolved substances from tbe water ; that, in fiict, the lolabie
salts of lime, and the like, were removed by some peculiar physico-mechanica] force,
resident, as it appears, as a surfhce force, in all porous masses. There are many tctt
remarkable examples in nature of the operation of this power in prodoeing bedi
•barged with metsUliferous matter, some of which will be described under the bead of
IflNINO.
Mr. H. M. Witt communicated to the PhUoaophieai Magazine tor December, 1856, n
account of some experiments on filtration, which ore of much value. Hanj of hif
experiments were made at the Chelsea Water Works, and they appear of aucb interest
that we quote the author's remarks to some extent
** The system of purification adopted by the Chelsea Waterworks, at their works it
Chelsea, consisted hitherto (for the supply has by this time commenced from Kiogs-
ton) in pumping the water up out of tbe river into subsiding reservoirs, where it r^
mamed for six hours ; it was then allowed to run on to the filter-beds. These are
large square beds of sand and gravel, each exposing a filtering surface of about S70
square feet, and the water passes through them at the rate of about 6| gallons per
square foot of filtering surface per hour, making a total quantity of 1687*5 gallons per
hour through each filter.
** The filters are composed of the following strata, in a descending order : —
ft. in.
1. Fine sand - - -26
2. Coarser sand - - . - - . -10
3. Shells - -06
4. Fine gravel - -•- - - . -OS
5. Coarse gravel - - - - - - -33
These several layers of filtering materials are not placed perfectly flat, but are dis-
posed in waves, and below the oonvex curve of each undulation is placed a poroas
earthenware pipe, which conductB the filtered water into the mains for distributioa.
The depth of water over the sand was 4 feet 6 inches. The upper layer of sand is
renewed about every six months, but the body of the filter has been in use for aboot
twenty years.
«< Samples of water were taken and submitted to examination :-^
** 1st, fh>m the reservoir into which the water was at the time being pumped fVom
the middle of the river.
" 2nd, from the cistern, after subsidence and filtration."
Experiments were made at different seasons of the year ; but one of Mr. Witt's
tables will sufficiently show the results.
1. Shows the quantities of the several substances originally present, represented io
grains, in the imperial gallon (70,000 grains) of water.
2. The amount present after filtration.
3. The actual quantities separated in grains in the gallon of water.
FILTRATION.
211
4. The per centage ntio wbich the amonnts separated bear to the qnantities
origiimllj present.
1.
Oriftnally
pr«MnC.
2.
After mtraUoD.
3.
Arooant
Mparated.
4.
Per ceniJige ratio
of leparated
Matter.
Total solid residue, includ-
ing sospended matter
Organic matter
Total mineral matter
Sospended matter -
Total dissolTed 8alu
lime ....
55-60
4*05
51-55
28*93
22-62
8-719
22-85
1-349
21*501
2*285
19-216
8-426
32-75
270
30*049
26-645
3-404
0-293
58-90
66-66
68-29
9210
15-04
3*36
" It has been assumed as a principle that sand filtration can only remore bodies
mechanically suspended in irater, but I am not aware that this statement has been
established by experiment ; in fact, I am not acquainted with any published analytical
examination of the effects of sand filtration.
*" These experiments supply the deficiency, and show, moreover, that these porous
media are not only capable of removing suspended matter (80 to 92 per cent.)* but
even of separating a certain appreciable quantity of the salts from solution in water,
tIz. from 5 to 15 per cent of the amount originally present, 9 to 19 per cent of the
common salt, 3 per cent, of the lime, and 5 of the sulphuric acid.
'* Taking the purer water from Kingston, two experiments were made simultaneously
with the same water, one filtration being through charcoal alone, and the other through
sand alone, the sand filter having an area of 4 square feet, and consisting of the
following materials : —
ft. In.
Fine sand • - - -- - . -19
Shells n
Gravel l}
Coarse gravel -------- 9
2 9
Results of Sand Filiratiaiu
Original
W*tOT
•Md.
After Y3 bourC action.
AftOTlVOhovn'actkn. |
CwnpvlMMi.
Amoqnt
Mparaicd.
Per ccntaRe
of Quantity
■cparatcd.
Conpafkan.
AiBount
■cparatad.
ParemtMa
ratio or
QumtitT
wyaratM.
Total resMue
Mineral lalu ...
Organic matter
Stttpmdeil matter -
Chlorine - • .
Chloride of Sodium
24*fi78
38*687
0*8806
3-509
0-B62
1-420
83-87
1-013
2*663
• •
0-708
0-829
' 0-846'
2*88
8-50
34-109'
m »
23^
2304
0648
0-671
1-106
0-888
0 647
0*8426
0-191
0-315
3-613
3-73
2216
2811
Afts 840 taonn' acUon.
After 376 hovn' action.
Total rrddoe
Hineral salra ^ . -
Orfanlc matter
Suspended matter -
Chlorine ...
Chloride of Sodium
24-578
33-687
0*8906
S*509
0-863
1-420
28*S34
21*517
0^17
1*88
0-674
i-no
3D44
2-170
0 188
oaio
8-316
9-161
46*423
218
21-8
22-607
21-698
0-809
1*084
2*071
1-989
1*926
8*426
8-397
54*85
* Apart from its special interest, as compared with the following experiment, made
simuHaneonsIy through charcoal, the following points are in themselves remarkable
in the results obtained by this filtration through sand : —
" Ist. That the filter continued increasing in efficacy even till the conclusion of the
experiment >. e*> for 376 hours, not having lost any of its power when the experiment
was terminated.
** 2nd. That no weighable quantity of dissolved organic matter was removed by the
sand in this experiment ; but it must be remembered that the quantity originally
present was but small.
p 2
212
FIRE ANNIHILATORS.
*' 3rd. Its power of removing soluble salts was considerable ; as a maxtmam, 21 per
cent, of the common salt being separated. "
Remits of Charcoal Filtration,
used.
After 7S boun' acdon.
AftotllOboiti^Hliao.
1
ConpsiiMB.
Amooat
■cpsrstsd*
QoanUtT
•epaniML
ConpsilHiii
AoMrat
taOBMl
ntiotf
Total residue
Mineral salti ...
Organic matter
Suspended matter -
Chlorine ...
Chloride of Sodium
24-578
23-G87
0-8906
3-509
0-862
1-420
22'13
21-875
0-755
2-448
2-312
0-1356
9-906
9-76
15-22
21-644
806
2-934
0-449
lis
1«9
After MO hoonr KtioD.
After 376 iMan'aettM.
Total residue
Mineral salts . - .
Organic matter
Suspended matter -
Chlorine . . -
Chloride of Sodium
24-578
23-687
0-8906
3-509
0 862
1-420
20821
' 2-79 "
8-757
• •
' o-rw"
15-28
"ao-48 "
21-374
20^04
0-770
3-204
81B3
Qrim
13tS
tt'U
On comparing this experiment with the preceding, the following point comes «t
as showing the difference between the effects of sand and charcoal as filtenog
media. • ^ v iM
By the charcoal, speaking generally, a considerably larger quantity of the tooi
residue contained in the water was removed than by thejsand, their maximum resale
being respectiyely as follows : —
Amount originally
present
24*578 grs. in!
the gallon J
Amount separated in Grains in the
Gallon.
By Sand.
2-074
By Charcoal.
3-757
Amount separated in per eartsgerf
the Quantity present.
By Saad.
8-426
ByChsrcoal.
15-28
Mr. Way has also shown that agricultnral soil possesses the power of •*!*„, ^^J
the solnble salts and organic matter from water in a remarkaUe manner. ^^^
are without doubt many natural phenomena which are immediately ^P^j^
upon this power, posseted by porous bodies of all kinds, in a greater or
degree. *^
FIRE ANNIHILATORS. This name is given to a portable machine m^'"^
by Mr. Phillips, which U adjusted to produce the immediate production orw»»j
carbonic acid and other gases, which could be at once directed on the '^^
mass. The machine is cylindrical in form, and slightly conical. For use it "J^*^
with the following composition -. charcoal 20 parts, nitrate of potash 60 P^^.^^
gypsum 5 parts. These materials are boiled together in water, and *^®''^'lj, ^f $
in a stove at the temperature of 100°. The whole is moulded into the ^^^^^
brick, down the axis of which penetrates a hollow cavity for the reception ot ^ y^
which contains a mixture of chlorate of potash and sugar, surmounted by 4g
of sulphuric acid. The charge so prepared is placed in a cylindrical v^^
forated in many places, which is itself within another cylindrical vessel, *V ^^
forated for the passage of the gases ; both these are contained in a double ^y^^ jj
receiver, the lower part of which contains a quantity of water. The •PPrTjje n-
closed by two covers, in the outer of which is an opening for the escape oi ^
pour. In the centre of the cover is placed a spike, for the purpose of J****. J^^a
glass bottle deposited in the cavity of the charge. The spike being ^'"'P^^f the
breaks the bottle, and the sulphuric acid causes the instantaneous ^^^^^^^{hnyogli
chlorate of potash and sugar, which fires the charge. The gases now esc^p^ pjpaod,
the perforations, and heating the air in the water chamber, and causing it ^^ ^^.
forces the water up a tubular passage into the space between and around t ^.^^
drical vessels placed each within each, and being thus converted into ^^P^'\' ^\^
with the gases, and escapes by the discharge tube, forming a dense cioaoi
rapidly extinguishes flame.
FIRE ARMS. 213
FIRE ARMS, Manufacture of. This art u diyided into two branches, that of
the metallic, and that of the wooden work. The first includes the barrel, the lock, and
the mounting, with the bayonet and ramrod, for military arms. The second com-
prises the stock, and in fbwling-pieces likewise the ramrod.
71^ Barrd. — Its interior is called the bore ; itsd iameter, the calibre ; the back
end, the breeeh ; the front end the mozzle ; and the closing of the back end, the breech
pin or ping. The barrel is generally made of iron. Most military musquets and
low-priced gnns were formerly fitshioned out of a long slip of sheet- iron folded to-
gether edge-wise round a skewer into a cylinder ; they were then lapped over at the
seam, and welded at a white heat The most ductile and tenacious sojft iron, free from
all blemishes, must be selected for this slip. It is frequently welded at the common
forge, bat a proper air-furnace answers better, not being so apt to bum the iron,
which should be covered with ashes or cinders. The shape of the bore is given by
hammering the cylinder upon a steel mandril, in a groove of the anvii Six mches of
the barrel at either end are left open for forming the breech and the mnzxle by a sub-
sequent welding operation ; the extremity put mto the fire being stopped with clay,
to prevent the introduction of cinders. For every length of two inches, there are
from two to three welding operations, divided into alternating high and low heats ;
the latter being intended to correct the defects of the former. The breech and muzzle
are not welded upon the mandril, but upon the horn of the anvil \ the breech being
thicker in the metal, is more highly heated, and is made somewhat wider to save
labour to the borer. The barrel is finally hammered in the groove of the anvil with-
out the mandril, during which process it receives a heat every two minutes. In
welding, the barrel extends about one-third in length ; and for musquets, is even-
tually left from 3 to 3^ feet long ; but for cavalry pistols, only 9 inches.
The best iron plates for gun-barrels are those made of stub iron, that is of old
horse-shoe nails welded together, and forged into thin bars, or rather narrow ribands.
At one time damaacus barrels were much in vogue ; they were fashioned either as above
described, from plates made of bars of iron and steel laid parallel, and welded together,
or from ribands of the same damascus stuff coiled into a cylinder at a red heat, and then
welded together at the seams. The best modem barrels for fowling-pieces and the
modem rifles are constructed of stub-nail iron in this manner. The slip or fillet is
only half an inch broad, or sometimes less, and is left thicker at the end which is to
form the breech, and thinner at the end which is to form the muzzle, than in the
intermediate portion. This fillet being moderately heated to increase its pliancy, is
then lapped round the mandril in a spiral direction till a proper length of cylinder is
formed ; the edges being made to overlap a little in order to give them a better hold
in the welding process. The coil being taken off the mandril and again heated, is
struck down vertically with its muzzle end upon the anvil, whereby the spiral junc-
tions are made closer and more uniform. It is now welded at several successive heats,
hammered by horizontal strokes, called yum/>m^, and brought into proper shape on the
mandriL The finer barrels are made of still narrower stub-iron slips, whence they
get the name of wire twist On the continent, some barrels are made of steel wire,
welded together lengthwise, then coiled spirally into a cylinder. Barrels that are
to be rifl^, require to be made of thicker iron, and that of the very best quality,
for they would be spoiled by the least portion of scale upon their inside. Soldiers*
musquets are thickened a little at the muzzle, to give a stout holding to the bayonet
The barrels thus made are annealed with a gentle heat in a proper furnace, and
slowly cooled. They are now ready for the borer, which is an oblong square bit of
steel, pressed in its rotation against the barrel by a lip of wood applied to one of its
fiat sides and held in its place by a ring of metaL The boring bench works horizon-
tally, and has a very shaky appearance, in respect at least of the bit In some cases,
however, it has been attempted to work the barrels and bits at an inclination to the
horizon of 30^, in order to mcilitate the discharge of the borings. The barrel is held in
a slot by only one point, to allow it to humour the movements of the borer, which
woold otherwise be infallibly 760
broken.. The bit, as represented yrp - , . — p
in Jig. 760, has merely its ^
square head inserted into a
clamp-chuck of the lathe, and
plays freely through the rest of
its length.
Fia. 761 represents in plan
the boring bench for musquet
barrels ; // is the sledge or
carriage frame in which the barrel is supported ; a is the revolving chuck of the
lathe, into which the square end of the hit, fig. 760, is inserted; 6 is the barrel,
p 3
214 FIRE ARMS.
olamped at its middle to the carriage, and capable of being presfed oowaidi agaiosi
the tapering bit of the borer, by the bent lever c, worked by the left hand of tU
operative against fulcrum knobs at d, which stand about two inches asonder.
Whenever the barrel has been thereby advanced a certain space to the right, the bent
end of the lever is shifted against another knob or pin. The borer appears to i
stranger to be a very awkward and unsteady mechanism, but its perpetual yibrationi
do not affect the accuracy of the bore. The opening broach may be of a sqoarv
or pentagonal form ; and either gradually tapered from its thickest part, or of
uniform diameter till within two inches of the end, whence it is suddenly tapered to
a point
A series of bits may be used for boring a barrel, beginning with the smallest lod
ending with the largest. But this multiplication of tools becomes unnecessary, by
laying against the cutting part of the bit, slips of wood, called spales, of gradoalljr
increasing thickness, so that the edge is pressed by them progressively further from
the axis. The bore is next polished. This is done by a bit with a very smooth edge,
which is mounted as above, with a wedge of wood besmeared with a mixture of oilaod
emery. The inside is finished by working a cylindrical steel file quickly backwards and
forwards within it, while it is revolving slowly.
In boring, the bit must be well oiled or greased, and the barrel must be kept eool
by letting water trickle on it ; for the bit, revolving at the rate of 120 or 140 tiiiMSi
minute, generates a great deal of heat If a flaw be detected in the barrel doriogtbe
boring, that part is hammered in, and then the bit is employed to turn it oat
Many sportsmen are of opinion that a barrel with a bore somewhat narrowed tovaidi
the muzzle serves to keep shot better together ; and that roughening its inside with
pounded glass has a good effect, with the same view. For this purpose, also, fine
spiral lines have been made in their interior surface. The justness of the calibie of
a fowling-piece or musket is tried by means of a truly turned cylinder of ateel, 3
or 4 inches long, which ought to move without friction, but with uniform contact
ft'om end to end of the barrel Whatever irregularities appear must be immediately
removed.
The outer surfiice of the barrel is commonly polished upon a dry grindstone, hot it
is better finished at a turning lathe with a slide rest
Rifle barrels have parallel grooves of a square or angular form cut within them, each
groove being drawn in succession. These grooves run spirally, and form each an
aliquot part of a revolution from the chamber to the muzzle. Rifles should not be too
deeply indented ; only so much as to prevent the ball turning round within the barrel,
and the spires should be truly parallel, that the ball may glide along with a regular
pace.
The Parisian gun-makers, who are reckoned very expert, draw out the iron for the
barrels at hand forges, in fillets only one-ninth of an inch thick, one inch and a half
broad, and four feet long. Twenty-five of these ribands are laid upon each other, be-
tween two similar ones of double thickness, and the bundle, weighing 60 lbs., boood
with wire at two places, serves to make two barrels. The thicker pliUes are intended
to protect the thinner from the violence of the fire in the numerous succesave beats
necessary to complete tibe welding, and to form the bundle into a bar two-thirds of an
inch broad, by half an inch thick ; the direction of the individual pUtes relatively to
the breadth being preserved. This bar folded flat upon itself, is again wrought at the
forge, till it is oi3y half an inch broad, and a quarter of an indi thick, while the plates
of the primitive ribands are now set perpendicular to the breadth of the narrow fillet!
the length of which must be 15 or 16 feet French (16 or 17 English^ to form a foil-
ing piece from 28 to 30 inches long. This fillet, heated to a cherry red in saccessire
portions, is coiled into as close a spiral as possible, upon a mandril about two-fifths of
an inch in diameter. The mandril has at one end a stout head for drawing^ it ^J^
means of the hanmier and the grooves of the anvil, previous to every heating. Toe
welding is performed upon a mandril introduced after each heat ; the middle of the
barrel being first worked, while the fillets are forced back agunst each other, along the
surface of the mandril, to secure their perfect union. The original plates having in the
fbrmation of the ultimate long riband become very thin, appear upon the sor&ceoi
the barrel like threads of a fine screw, with blackish tints to mark the jonctiona u
making a double-barrelled gun, the two are formed from the same bundle of slips? the
coils of the one finished fiUet being turned to the right hand, and those of the other to
the left.
The barrels forged, as above described, ft-om a bundle of steel and iron plateslaid
alternately together, are twisted at the forge several times, then coiled and welded as
usual. Fifteen workmen concur In one operation : six at the forge; two at tbe
boring mill; seven at filing, turning, and adjusting; yet altogether make only^^
pairs of barrels per week. In the first instance, it will be understood, that, for (he
FIEE ARMS.
215
n of the mperior bureU, t, handle of hone-ihoe dbUs ii welded into ■ flit
bar, limilar bar* of icrap neel are made, andtheae are made np into a bundle, — a bar
of iron, aad > b«r of cteel — of eight or twelve ban, Thii ii again welded into ooe bar,
and the result u, when the sorface it poliihed, that the difference in the texture of the
Ti ia disdoctl^ Tiiible. Now, if two bare of iron and one of iteel, or two ban
ofn
a and a
9of ii
_ _ a Tarietj in the pattern of (he finiibed bar.
In constmcting the barrel thii bar tDsy be twiited op (ingly, ai deacribed, or two ban
differing m pattern may be welded together, and then twiated. It i« nmii to place two
bara logetfaer, to twist one into a screw and lesTe tbe other plain, or to giTC one a
light band twiat and the other a left handed one, or lometiiDea three ban are em-
plojed, and bj twining or otherwiae preTiooily to welding tha ban together and
taming or twisting the compound bar into B cylinder, a great rarieiy of pattemi are
prodn<»d on the finiibed barreL
The breeching ii of three kinds : the common ; the chamber, plog, or mortar,
fy. T6S : and the patent, fig. 763. The common was formerly nsed for soldier*'
musqnet* and inferior pieces. The le- ygg
cond is a trifling improrement apon it
la the patent breeching, tbe screws do
not interfere with tbe tonch-bote, and the 763
ignition ia qnicker in tbe main chamber.
The only locks which it is worth
wbile to describe are those apon the per-
cussion prindple, as flint locks have
ceased to be employed. Forsyth's lock
(Jig- 764) wsi an ingenious cootriiance.
Itfa«s a magaitne a, tbr containing thede-
(onating powder, which reTOlves round
a rotler b, wboae end is icrawed into the
brveeb of the barreL The priming pow-
der passes through a small hole m the
roIleT, which leads to a channel in com-
mnnication with the chamber of the gon.
The pan for holding the priming ii
placed immediately over the little hole
in the roller. There is a steel panch c,
in the magaiinev whose under end stands
above the pan, ready to ignite tbe priming when struck npon the top by the cock d,
whenerer the trigger i» drawn. The punch, immediately after bemg driven down
into the pan, it raited by the action of a spiral spring. For each explosion, the
magaiine must be turned so far round as to let fall a portion ot the pereuasion
powder iolo the pan ; after which it is turned back, and the sEeel punch recovers its
I»oper position for striking another blow into tbe pan.
Tbe mventioQ of the copper percustion cap was another great improvement upon the
detonating plan. Fig. T6S represents the ordinary percussion lock, which is happily
diveMed of three awkward projectious npon the flint lock, namely, the hammer,
bMDiuer apriog, and the pan. Nothing now appears upon the plate of the lock, but
tbe code or striking hammer, which inflicts Uie striking blow upon the percussion
op. It is concave, with a small metallic ring or border, called a shield or fence, for
the purpose of enclosing the cap, as it were, and preventing its splinten doing ii^ury
to the sportsman, as auo protecting againat (he line of flame which may issue ttoia
tbe touch-hole in the cap-nipple. This is screwed into the patent breech, and i* per-
forated with a amall hole.
216 FIRE ARMS-
The safety look of Dr. Somerrille if, in its essential featore, a slide stop or catch,
765
placed ander the trigger, i^^fig- 766. It is palled forward into a notch in the tiiggtri
by means of a spring b, npon the front of the goard, which ia worked by a kej c,
766
pressing upon the spring when the piece is discharged. In another safety plan there
IS a small movable curved piece of iron, a, which rises throngh an opening n, in the
lock- plate c, and prevents the cock from reaching the nipple, as represented in the
figure, until it is drawn back within the plate of the lock when the piece is fired.
To fire this gun, two different points must be pressed at the same time. If ^
accident the key which works the safety be touched, nothing happens, becanse the
trigger is not drawn ; and the trigger touched alone can produce no effect, because it
is locked. The pressure must be applied to the trigger and the key at the sidk
instant, otherwise the lock will not work.
The old French musket is longer than the British, in the proportion of 44*7S inches
to 42 ; but the French bayonet is 15 inches, whereas the British is 17.
Eng. DimeotloDi. Fr. DiBWMh"*-
Diameter of the Bore ....
Diameter of the ball - - - -
Weight of the ball in oz. - - -
Weight of the firelock and bayonet in lbs.
Length of the barrel and bayonet -
Within these few years a great many contrivances for fire arms have been bronght
forward, and several have been patented. The first is that of Charles Random.
Baron de Berenger. Ft^. 767 shows the lock and breech of a fowling piece, v>th *
sliding protector on one of the improved plans ; a is the hammer, h the nipple of J^
touch-hole, c a bent lever, turning upon a pin, fixed into the lock-plate at (2. /r
upper end of this bent lever stands partly under the nose of the hammer, and while "^
0-75 in.
0-69 UL
0-676
0-65
1-06
0-958
12-25
10-980
6900
59-72
FIRE ARMS. 217
chat sitnatioD stops it fh>m striking the nipple. A sMder gfh, connected with the
onder part of the gun-stock, is attached to the tail of the bent leyer at i ; aiid when the
767
piece la brought to the shoulder for firing, the hand of the sportsman pressing against
the bent fwrt of the slider at o, forces this back, and thereby moves the end of the
lever c forwards from under the nose of the cock or hammer, as shown by the dotted
lines. The trigger being now drawn, the piece will be discharged ; and on removing
the hand firom the end jTi of the slider/, the spring at h acting against the guard, will
force the slider forward, and the lever into the position first described.
Mr. Bedford, gun-maker, of Birmiugham, introduced a modification of the lock for
small fire-arms, in which the application of pressure to the sear spring for dischargiug
the piece is made by means of a plug, depressed by the thumb, instead of the force of
the finger exerted against the trigger. Fig. 768 represents a fowling piece partly in
768
actioo. The sear spring is shown at a. It is not here connected with the trigger as
in other locks ; but is attached by a double-jointed piece to a lever b, which turns upon
a fnlcmm pin in its centre. At the reverse end of this lever an arm extends forwards,
like that of an ordinary sear spring, upon which arm the lower end of the plug c is
intended to bear ; and when this plug is depressed by the thumb bearing upon it, that
end of the lever b will be forced downwards, and the reverse end will be raised, so as
to draw up the end of the sear spring, and set off the piece. For the sake o£ pro-
tection, the head of the plug c is covered by a movable cap d, forming part of a slider e,
which moves to and fro in a groove in the stock, behind the breech end of the barrel ;
this slider e is acted upon by the trigger through levers, which might be attached to
the other side of the lock -plate; but are not shown in this figure to avoid confusion.
AVhen the piece is brought to the shoulder for firing, the fore-finger must be applied
as usual to the trigger, but merely for the purpose of drawing back the slider e, and
uncovering the h<»d of the plug ; when this is done, the thumb is to be pressed upon
the head of the plug, and will thus discharge the piece. A spring bearing against
the lever of the slider e, will, when the finger is withdrawn from the trigger, send the
slider forward again, and cover the head of the plug, as shown.
The Rev. John Somerville, of Currie, in April, 1835, obtained a patent for a further
invention to prevent the accidental discharge of fire-arms. It consists in hindering
the hammer from reaching the nipple of a percussion lock, or the flint reaching the
steel of an ordinary one, by the interposition of movable safety studs or pins, which
protrude from under the &lse breech before the hammers of the locks, and prevent
them from descending to strike. These safety studs or pins are moved out of the
way by the pressure of the right hand of the person using the gun only when in the
act of firing, that is, when the force of the right hand and arm is exerted to press the
butt end of the stock of the gun against the shoulder while the aim is taken and the
trigger pulled. In carrying the gun at rest, the proper parts of the thumb or hand
do not come over Mr. Somerville's movable buttons or studs.
Fig. 769 is a side view of part of a double percussion gun $ Bndjig. 770 is a top or
plan view, which will serve to explain these improvements, and show one, out of many,
methods of carrying Uiem into effect a is the stock of the gun ; b the barrels ; c the
breech ; d th^ nipples $ s the false breech, on the under side of which the levers which
218
FIRE ASMS.
work the lafbty stads orpins are placed ; p is the shield of the fUse breech; atriggen;
K the lock-plate; and z the hammers » all of -which are eonstmcted as vsoal : a a ir
769
(^
the safety studs or pins, which protrode before the shield f, and work throngli goide
pieces on the ander side of the &lse breech. The button piece is plseed in the
770
771
position for the thumb of the right hand to act upon it ; but when the pressure of the
ball of the right thumb is to produce the movement of the safety studs, it most \x
placed in or near the position k ; and when the heel of the right hand is to effect the
movements of the safety studs, the button piece must be plaeni at l, or nearly Ba
In these last two positions, the lever (which is acted upon by the button piece
to work the safety studs through a slide) would require to be of a different shape
and differently mounted. When the hammers are down upon the nipples after dis-
charging the gun, the ends of the safety pins press against the inner sides of the
hammers. When this invention is adapted to single-barrelled guns, only one pis. o,
one lever and button piece will be required.
Mr. Richards, gun-maker, Birmingham, patented a modification of the copper eap
for holding the percussion powder as represented >^. 771 ; in which the powder m
removed from the top of the cap, and brought nearer the mouth; a being the top.^
the sides, and c the position of the priming. The dotted lines show the direction of
the explosion, whereby it is seen that the metal case is opened or distended ool/ »
a small degree, and not likely to burst to pieces, as in the common caps, ^^f?^
between a and c being occupied by a piece of any kind of hard metsl i loldcfedor
otherwise fastened in the cap.
George Lovell, Esq., Director of the Royal Manufactory of Arms at Enfield, intro-
duced an improvement upon the priming chamber. He forms it into a verticti
double cone, joined in the middle by the conunon apex; the base of the upptrecM
bein^ in contact with the percussion cap, presents the most extensive snrfiioe totbe
fulmmate upon the one hand, while the base of the under one being in a line with the
interior surface of the barrel, presents the largest sur&ce to the gunpowder cbaii;«,
upon the other. In the old nipple the apex of Uie cone being at its top, afforded very
ii^udiciously the minimum surface to the exploding force. ,
Gum, Eifling of€kt Barrels, — The outside of rifle barrels is, in general, ocH^
After the barrel is bored, and rendered truly cylindrical, it is fixed upon the nflmg
machine. This instrument is formed upon a square plank of wood 7 feet longi ^ '^^^
is fitted a tube about an inch in diameter, with spiral grooves deeply cut inteniai'/
through its whole length ; and to this a circular plate is attached about 5 inehtf
diameter, accuratel^r divided in concentric circles, into from 5 to 16 equal parts, w'*
supported by two rings made fast to the plank, in which rings it revolves. An »J*
connected with the dividing graduated plate, and pierced with hdes, through which s
pin is passed, regulates the change of the tube in giving the desired number of gr^o^
to the barrel. An iron rod, with a movable handle at the one end, and a steel cntttf
in the other, passes through the above rifling tube. The rod is covered with a core pt
lead one foot long. The barrel is firmly fixed by two rings on the plank, standing ii^
a straight line on the tube. The rod is now drawn repeatedly through the barrel, fr^
end to end, until the cutter his formed one groove of the proper depth. The po> ^
FIRE ARMS.
219
then dufted to another hole in the dividing plate» and the operation of grooviog is
repeated till the whole number of riflings is completed. The barrel is next taken oat
of the machine, and finished. This is done by castin|p upon the end of a small iron
rod a core of lead, which, when besmeared with a mixture of fine emery and oil, is
drawn, for a considerable time, by the workmen, fh>m the one end of the barrel to the
other, till the inner surftuie has become finely polished. The best degree of spirality is
found to be from a quarter to half a revolution in a length of three feet
Military RiJUa. — An essential improyement in this destmcdTC arm has been in-
trodnced into the British sendee.
The intention in all rifles is to impart to the ball a rotatory or spinning motion
roond its axis, as it passes out through the barrel. This object was attained, to a
certain degree, in the rifles of the old pattern, by cutting seyen spiral grooves into the
inside of the batrel, in the manner shown hy fig. 772, the spherical ball,y^. 77d, being
a little larger than the bore, was driven down with a mallet, by which the projecting
ribs were forced into the surface of the ball, so as to keep it in contact with their
curvatures, during its expulsion. Instead of this laborious and insecure process, the
barrel being now cut with only two opposite grooves, fig. 774, and the ball being formed
with a projecting belt, or zone, round its equator, of the same form as the two grooves,
fig. 775» it enters so readily into these hollows, that little or no force is required to
press it down upon the powder. So much more hold of the barrel is at the same time
obtained, that instead of one quarter of a turn, which was the utmost that could be
772
778
774
775
safely given in the old way, without danger of stripping the ball, a whoU turn round
the barrel in its length, can be given to iht two grooved rifles ; whereby a far more
certain and complete rotatory motion is imparted to the ball. The grand practical
result is, that better practice has been performed by several companies of Uie Rifle
Corps, at 300 yards, than could be produced with the best old military rifles at 150
yards; the soldier being meanwhile enabled to load with much greater ease and
despatch. The belt is bevelled to its middle line, and not so flat as shown in the figure.
This mode of rifiing is not, however, new in England. In fact, it is one of the
oldest upon record ; and appears to have fallen into disuse from faults in the execution.
The idea was revived within the last few years in Brunswick, and it was tried in
Haoover also, but with a lens-shaped {Linaenflrmig) ball. The judicious modifica-
tions and improvements it has finally received, have brought out all its advantages,
and rendered it, when skilAilly used, a weapon of unerring aim, even at the distance
of 700 yards.
The locks, also, for the military service generally, are receiving important Im-
Ifr. LovdVs Lock.
provements. In Loveirs lock the action of the main spring is reversed, as shown by
fig. 776 ; thus rendering the whole mechanism more solid, compact, and convenient }
220
FIRE ABMS.
while the ignition of the charge is effected hy percussion powders in a eofiper eap.
Mr. Lovell, inspector of smaU arms for her Majesty's service, and director cf the
777 7gl Boyal manufactory, at Enfield Chase, directed his mind to tb€
constraction of a snre, simple, and strong musket, with r\iA,
under his superintendence, the whole of her Majesty's soldim
were long provided. He has also furnished them vith a
, short, but clear set of instructions for the cleaning aDdIna!lag^
ment of these excellent arms, illustrated by a series of wood
engravings. From this little work the following notice is
copied.
^t^. 777. The barrel, reduced to one-seventh size, a, the
breech ; 6, the nipple^seat or lump ; c, the back sight ; i, the
back -loop ; e, the middle loop ; /I the swivel-loop; 9, thefroot
loop, with the bayonet-spring attached ; A, the front sight;
t, the muzzle.
Fig. 778. The breech-pin, half size, a, the tasg; &,the
neck ; c, the screw threads ; </, the face.
0
d
@
A
I
Da
778
Fig. 779. The bayonet-spring, two ways, half size, a, the
shank ; 6, the neck ; c, the hook ; </, the mortice.
Fig, 780. The nipple, full size, a, the cone ; 6, the sqcares ;
c, the shoulder ; d, the screw-threads ; e, the touch-hole.
779 780
a
V— /
Fig. 781. The rammer reduced to one-seventh size, flithe
head ; 6, the shaft ; c, the screw threads.
Fig. 782. The lock, outside, half size, a, (he plate ; A. the
cock ; c. the tumbler-pin ; f/, the hollow for the nipple seat
Fig. 783. The lock, inside, half size, showing all the parts
in their places with the cock down at bearer, a, the msij-
spring; 4, the sear-spring ; c, the sear; rf, the tumbler; e, the
bridle ; /, the main-spring-pin ; g^ the sear-pin ; A, the Ktr-
spring-pin ; t, the bridle-pin.
Barrel-welding by Machinery. — The barrels of mnsqwB,
birding-guns, &c., or what are called plain, to distingaish thfo
from those denominated stub or twisted barrels, have of We
years been formed by means of rolls, a process in which tne
welding is first effected on a short shib of thick iron, and tbM
the barrel is brought down to its destined length and ^''^'^^
repeatedly passing it between a pair of rolls, that hare Men
, previously grooved to the exact ^ape of the barrel intcndw
to be mad^. .
The iron being thoroughly refined, and reduced into flat burs by the process de
scribed, is cut by the shears into slabs or lengths of 10 to 12 inches, ^^ 1^?
lOj lbs. weight, or less, according to the description of gun-barrel that is "^*?°5J
to be taiade. These slabs are then heated, and bent in their whole length, 0
means of conveniently goooved bending rolls, until they assume the form of roog
tubes, of the kind of section shown by a. Jig. 784. They are then placed on tw
hearth of the reverberatory furnace, and brought to a full welding heat, and »
soon as the edges of a tube come to a semi-fluid state, it is taken oat and pa^
between rolls having grooves somewhat smaller in diameter than the exterior of tfl
I
FIRE ARMS.
221
tnbe; hj which means the tabe is perfectly welded (Vom end to end; and if care be
taken in the management of the heat, and the janctore be kept clear of dirt and
cmders» the iron irill be found perfectly homogeneoos in erery part, and there will be no
appearance whatever of the seam where the the edges came together. These tnbes
are repeatedly heated, and passed between the barrel rolls, which are of sofficient
783
diameter to admit of gradually decreasing grooves, the whole length of the intended
barrel being indented on their sur&ces.
To preserve the tabular form, and insure regularity in the size of the bore during
the w^elding process, they are taken out of the furnace, by thrusting into them a tool
called a mandril, b. Jig. 786, which consists of a long rod of iron, having a short steel
treblett on its end, of the diameter that the bore of the barrel is meant to be. This
rod is ao adjusted by means of a strong iron plate c, near its handle, which is of wood,
and long, that when passed with the heated tube on it between two transverse holding
bars, the short steel treblett i> shall be foimd exactly between the point of impact of the
barrel rolls, e, b.
785
e
The adhesion of the hot iron to the suHkce of the rolls is Strong enough to draw
the tube off the mandril, which thus keeps the bore open fVom end to end, and by
repeating the process through the whole series of grooves in the rolls, the barrel is
222 FIBE ABMS.
gradually elongated, and broogfat down to the exact form reqoind ; aoj npcfflmi
length at the mnaale is then cut off. The breach end is then a4jaited by tiie haanttr
— a triple-seat welded on by band if it be intended for a percoflsaon lock ; and dun the
barrel is ready to go forwaid to the mill to be bored, tamed, and finished.
Gun barrels formed by this mechanical method are foond to stand proof better tki
those worked by hand, because the heat is more eqoalised ; and any imperfectiou in
the original mass of iron are more dispersed over the whole extent of the tabe.
Of late years large strides have been made towards increasing the efficacy of mili-
tary fire-arms.
The first attempt to inproye the rifle in nse in the French army, was that propoied
by M. Delvigne, an officer of the royal ex-goard (^fg. 786), in which the opper
786
orifice of the chamber that contuned the powder took the form of a cap, wherein tb«
ball (somewhat wider in diameter) was receiyed, and by two or three smutblovKrf
a heay}'-headed rammer (also capped out for the purpose) became expanded laterallv,
and thus the rotary motion was imparted to it by the spiral grooves of the barrel m
passing oat Colonel Poncharra suggested the addition of a wood bottom or sabot
under the ball and a greased woollen patch ; and Colonel Thonyesino proposed Ify.
787) a steel stem or pillar about 2 inches long inserted into the face of the breech-
H)
pin ; round this pin the charge of powder was received, and the diameter of the bill
when resting on the top of me pin, was enlarged by the blows of the heary-faettled
rammer, as suggested by Delvigne.
This system took the name of " Carabine H Tige,*' and has been very generally intro-
duced for the service of fusilier battalions in continental armies ; very grave olgectioDi,
however, have been found agunst it in use, fh)m the impossibility of keeping the cbsmber
(or part round the pin) clear ; and from the severe labour to the soldier in nnuniDg
down and enlarging the diameter of the ball sufficiently to insure the rotsry motioo
desired.
But if the ultimate results thus attained with spherical balls turned out not entirely
satisfactory, it was made clearly manifest, in the course of the experiments ctnied
on, that no insuperable difficulty stands in the way of rendering the ^re of inftntrj voy
much more accurate and powerful, by the use of rifled barrels throughout thearmjr, tnd
thus leading to a verification of the prediction made by Robins above one hundred jetfi
a^o, that " whatever state shall thoroughly comprehend the nature and advantageKif
rified barrel pieces, and having facilitated and completed their oonstructioD, shall in-
troduce into their armies their general use, with dexterity in the management of then,
will by this means acquire a superiority which will almost equal any thing that bas
been done at any time."
But besides smoothing the way to such an essential improvement, it has been elicited
of late years, that when the accuracy of fiight is secured by the rotary motion deri^
from the rifling, the bullet, instead of being limited to the form of a sphere as hereto*
fore, may, up to certain limits, be elongated with considerable increase of dettnctiTe
effect ; and with an augmentation of range very much beyond any thing that b^
hitherto been considered to lie within the reach of small arms — placing them, in^'*
with reference to artillery and cavalry, in the first place instead of the last
An immensely extended field has thus been opened to experimenters. 1st. ModI|
Didion proposed a true oval (Jig. 7 88) as the best form of bullet, so that* when atof^
by the blows of the heavy rammer and widened in its diameter, it might be brcMig&t
nearer to the spherical shape before leaving the barrel. . ,
2nd. Mons. Delvigne took a patent for a bullet (fig, 789) under the designation rf
" Cylindro Ogivale ; " it had a conical opening behind, in which he imagined that On
force of the powder would exert itself with sufficient energy to expand the lead ptf|f>**
nently, and so make the ball take the rotatory movement derived fh>m the rifiingt ^'
out any feitigue to the soldier in loading : with this projectile, indeed, the operatiootf
but slightly more difficult than with the ordinary cartridge and smooth barreb.
FIRE ARMS.
223
The bullet (Jig, 790) of the «* Carabine I, Tige " was oalled ** Cylindro Coniqae,** and
was Mid to pngiew this adyantage over the preceding, that, being brought more to a
point in front, it bored its way through the air with greater ease, and thus retained
788 789 790 791 792
^
greater velocity, and of course, more extended range; and with this bnllet it was that
Moos. Tamisier introduced three sharp-edffed cbaonels round it, which he stated were
necessary to keep its flight steady, by offenng a resistance to the action of the air.
Finally Mons. Minie, an officer of the French line, suggested {fig, 791) the addition of
a denoyau or culot to the hollow ball of Delvigne. This, in the form of a little cup
made of sheet iron, is placed in the orifice of the conical hollow of the ball behind, and
by the enerj^ of the powder is driven into the ball, enlarging its diameter permanently,
and thus giving all the accuracy of the rifle, with nearly the same fiusility of loading
as with the plam barrel.
The principle of the invention, as thus developed, has, we learn, been adopted by our
government for the general use of the army, seeing that it offers so great advantages
over the system of plain barrels, but the bullet {fig. 792), as modified by the Inspector
of Small Arms, has on its exterior no channels, they being found not only useless as to
steadying the flight of the projectile, but absolutely injurious in lowering its velocity.
The bullet in its improved form too, being more truly balanced in its proportions,
and made by mechanical means instead of b^ casting, has no tendency to the gyrations
which appear to have so puzzled French artillerists, and for which they have invented
the word ** derivation," and wasted much learned disquisition.
Bat even if it were ever to happen, which is not likely, that these various projectors
could be brought to agree as to the best form of projectile, they will then find out,
that although by the general introduction of rifled and elongated bullets an immense
advantage has been realised over plain barrels, their plans, based as they all are upon
a system of loading at the muzzle, are at best but one step in advance ; and that a good
sound military fire-arm loading at the breach will, after all, remain the great desideratum
— an arm tlmt, without any less accuracy or power to reach masses of artillery or
cavalry at a thousand yards' distance, will enable the soldier to triple the quantity of
his fire at any moment that he may be called upon to repel a charge of cavalry or
attack or defend a breach at close quarters ; of such simple construction, and so easily
handled in every position of the body, that the soldier can pour every shot of his most
murderous fire upon the enemy with unerring precision, whilst he himself may lie
coolly behind a stone or in a ditch in entire security.
These are no longer wild imaginings, although so many hundreds of attempts towards
the same object, from the earliest period to Uie present day, have been one after another
seen invariably to fail. The Germans have been long and steadily pursuing the great
object, until at length Herr Dreysa, of Sommerda in Thuringia, has succeeded, after
more than twenty years of continued labour, in establishing a musquet, under the name
of ** Zundnadelgewehr," which if not quite perfect, is so well adapted for the uses to
which it is applied that the "Prussians have armed the whole of their line and the
Landwehr with this weapon.
The needle musket (fig, 793) consists of a strong socket a, open on the upper side
and screwed on to the barrel 6, which is rifled in the usual manner ; within this socket
is a slider c, which in fiict constitutes the lock, as it contains the spiral spring and
224 FIRE WORKS-
mechanism that prodaee ignition by percossion ; it has a stoat hebel, or hindle, bj
which it is moved backwards and forwards freely. The cartridge {fig. 794) eoniitti
794 of the ball a, the sabot 6, or bottom of hard paper, and holding the
priming matter, and lastly the charge of powder c, the whole beiog mide
&k up in paper pasted together. In use the slider being drawn btck, the
//\\ soldier puts the cartridge with the point of the bidl in fixmt into the
// \\ open breach of the barrel, pushes the slider forward, and Mcmei in
close junction by a turn to the right against an inclined edge of the
open socket. The spiral spring is then brought into action by prasiog
the spring case forward with the thumb.
To Captain Drayson, B. A., we are indebted for the following. The
Enfield rifle, which has lately been approved of for the use of the tmj,
is constructed principally by machinery.
The factory at Enfield, at which this arm is maDofactored, is coniidered
one of the most complete establishments in the world.
The barrel, lock, wood-work, furniture, and bayonet are all conitmcted
at Enfield, and as each portion is made exactly of the same size aod shjpe,
a part of one rifle will fit into the same part of another.
The total length of this weapon, including bayonet, is 6 ft Oi in. bog,
and weighs 9 lb. 3 oz. ; the barrel is 3 ft 3 in. in length, and weighs 4 Ih.
8 OS. ; the diameter of bore is *577 inch. The bullet is elongated, and rotates on leariog
the piece like a spherical bullet The general figure of the bullet is cylindrical, batitt
iVont end is rounded, and its rear end has a conical-shaped cavity. In the Minie
rifle, some of which were introduced into the service, a small iron cap was placed in
the hollow at the rear end of the ball for the purpose of causing the ballet to
expand, but in the Enfield rifle this opening is filled by a wooden plug instead.
This dbninishes the fouling of the bore, and answers all the purposes of expansion.
The bullet is *568 inch, length 1*062 inch, weight 530 grains. The barrel is proTed
at Enfield, and when flaws are supposed to exist as much as 1 5 drams of powder
have been fired, without bursting the barreL The service charge is 2^ drams. The
weight of 60 rounds of ammunition including 75 caps is 5 lb. 8 oz.
The bore has three grooves, each groove forms a spiral of } a turn in 3 fleet 3 inches.
The rifle is sighted up to 900 yards, but an effective range may be obtained bejood
that distance.
The number of rifles lately turned out at Enfield is from lOOO to 1200 per week;
but there is shortly to be an mcrease in this quantity, when it is expected that opwards
of 1 600 per week will be turned out
For neatness and completeness of workmanship, as well as for efficiency, the EDseid
rifle is undoubtedly superior to any other fire-arm yet in use.
FIRE BRICKS. See Bricks and Clat.
FIRE-DAMP; the carburetted hydrogen of coal-mines, produced, in some css«,
by the slow decomposition of the coal itself; in others, it is probably the resolt of um
chanffes in the constitution of the vegetable matter of which the coal itself is formed,
which has been confined under great pressure in the interstitial spaces of the coal beds
or rocks immediately in connection with them. The accumulation of this gss i^ ^
** goaf," or waste spaces of a coal mine, is probably due to the changes which the
e(Mil itself undergoes. The sudden outbursts of this gas, known as ** blowers," are do
doubt the result of the liberation of the gas by suddenly removing the pressore under
which it has been confined. This gas is the constant product of the decompocttiop of
carbonaceous bodies under water ; it has hence been also called marsh gas. h i^ *
protocarburetted hydrogen, its formula being C'H^.
This carburetted hydrogen gas does not explode when mixed with air in a P'^'
tion much above or below the quantity necessary for complete combustion. vTith
tbree or four times its Tolume of air it does not explode at all, with five and a half^
six volumes of air it detonates feebly, and with seven or eight most powerfiu|T*
When mixed with fourteen volumes of air the mixtufe is still explosive, bat «iu^
larger proportions of air the gas only bums about the fiame of the taper. See Sirs^
La.mp and Miking.
FIRESTONE, signifies a stone which will bear the heat of a fhmace withoat trivxj-
In geology the term is generally applied to the sandstone which occurs at the top «
the upper green sand in the south of England, which, from its power of withstand^
the effects of heat is frequently used for lining kilns and furnaces. It is a S^^^
calcareous sandstone, soft, and easily worked in any direction when first taken rroin
the quarry ; but on exposure it becomes extremely hard and durable, and well soited
for bnildinff purposes. Many of the older churches in Dorsetshire are built of tois
stone.-— H.W.B.
FIRE WORKS, See Pybotechny.
FLANDERS BRICKS- 225
FIR-WOOD. (Abiei.) 1. Ths Sii.veb Fir, PiuiaM abies. (Sapim Commun^
Fr.; Weiss Oder Edd Tarnne^ Germ.) S. Scots Fib, JVfiitff syhestris. (Pte
lyEcotse, Fr. ; Kiefer Oder Fdhre, Germ.) These are valuable as timber-trees, and
for the resinous juices which exude from them.
FISH SKIN. The skin of the dog-fish, shark, and other ganoids, used occasionally
in polishing and in cleaning rounded and irregular works in pattern making.
FLAGSTONE: a stone which splits freely in a particular direction along the
original lines of deposition of the rock. These are i^enerally sandstones, and the
splicting surfitces are frequently prodoced by thin lamme of mica; but thin bedded
limestones also furnish flagstones, of which some beds of Furbeck limestone and
the Sconefield slates are examples. Flagstones are also obtained fh>m Lias limestones^
which are, in fact, thin beds of indurated clay. — H. W. B.
FLAKE WHITE. This namie is applied indiscriminately to pure white lead, and
to the trisnitrite of bismuth.
FLAME (^Ftamme, Fr. and Genu.), in the ordfaiary acceptation, is the combustion
of a mixture of an inflammable gas or vapour with air. That it is not, as many sup«
pose, combustion merely at the exterior surface where the gas and the air come
in contact with each other, is proved by passing a fragment of phosphorus or
snipkar into the centre of a large flame. Eithsr of these bodies ignited in
passing tkrongh the film of flame will continue to bum there with its peculiar
light ; thus proving that oxygen is mixed with the vapour in the interior. If we
mix good coal gas with as much atmospheric air as can convert all its carbon into
carbonic acid, the mixture will explode with a feeble blue light; but if we mix the
same gas with a small quantity of air, it will bum with a rich white flame ; a know-
ledge of this &ct has led to the practice, in many of our large gas works, of pumping
air into the gasometers with the coal gas, a dishonest and a dangerous system. In
the latter case, the carbonaeeous partides are precipitated, as Sir H. Davy first showed,
in the interior of the flame, become incandescent, and constitute white light : for from
the ignition of solid matter alone can the prismatic rays be emitted in that concen-
trated nnion. Towards the interior of the flame of a candle, a lamp, or a gas jet,
who'e the air is scanty, there is a deposition of solid charcoal, which, by its ignition,
increases in a high degree the intensity of the light. If we hold a piece of fine wire
gauze over a jet of coal gas close to the orifice, and if we then kindle the gas, it will
bum above the wire with its natural brilliancy ; but if we elevate the gauze progres-
sively higher, so as to mix more and more air with it before it reaches the burning
point, its flame will become &inter and less white. At a certain distance it becomes
blue, like that of the above explosive mixture. If a few platina wires be held in that
dim flame they will gprow instantly white hot, and illuminate the apartment On re-
versing the oi^er of this experiment, by lowering progressively a flat piece of wire
gauze from the summit towards the base of a gas flame, we shall find no charcoal
deposited at its top, because plenty of air has been introduced there to convert all the
carbon of the gas into carbonic acid ; but as we descend, more and more charcoal will
appear upon the meshes. At the very bottom* indeed, where the atmospheric air
impinges upon the gauze, the flame is blue, and no charcoal 'can therefore be depo*
sited.
The fiurt of the increase of the brilliancy and whiteness of flame by the development
and ignition of solid matter in its bosom, illustrates many curious phenomena. We
can thus explain why defiant gas affords the roost vivid illumination of all the gases;
because, being surcharged with charcoal, its hydrogen lets it go in the middle of the
flame, as it does in an ignited porcelain tube, whereby its solid particles first get ignited
to whiteness, and then bum away. When phosphorus is inflamed, it always yields a
pure white light, irom the ignition of the solid particles of volatilised phosphorus
rapidly converted to phosphoric acid.
In the blowpipe flame from an oil>lamp or a candle, the inner blue flame has the
greatest heat, because tiiere .the combustion of the whole fatty vapour is complete.
The feeble light of burning hydrogen, carbonic oxide, and sulphur, may, upon the
principles now expounded, be increased by simply placing in them a few particles of
oxide of zinc, slender filaments of amianthus, or fine platina wire. Upwards of
twenty years ago Dr. Ure demonstrated, in his public lectures in Glasgow, that by
narrowing the top of a long glass chimney over an argand flame either from oil or
coal gas, the light could be doubled, at the same cost of material. The very tall
chimneys used by the lamp-makers are very wasteful, as they generate a strong
current of air, and the combustion of the solid matter is carried on with great rapidity.
With a narrow chimney of half the length we can have nearly as good a light, and
save 80 per cent, of the oil. See Blowpipe.
FLANDERS BRICKS, commonly called Bath bricks. These are made in large
qvantities at Bridgewater, from the silty clay deposited in the estuary, which contain^
Vox. n. Q
226 FLAX.
a large quantity of fine sand. These bricks are mncli nsed fbr domestie pnipoaci,
also in making founders* cores, and for polishing some sted articles.
FLANNEL. A plain woollen stuff of a rather open and slight fikbrie. See
Woollen Manufactures.
Wales is the country in which flannel was orig^ally made, and the Welsh flaimd
is still held in much estimation. Haud labour is still employed in the produc-
tion of Welsh flannel, and though it is not so cheap as some others, the quality and
finish of this fabric generally causes it to be preferred for vests worn next the
skin and similar purposes. Flannels are now made more extensiTely at Boohdsle than
in any other part of the world. In that neighbourhood the manufacturers produce the
greatest variety of widths, finish, and substance, yiz. : the thin, the medinn, tin
thick, double nused, and swanskin. Saddleworth produces the so-called Saxony
fliannels, which are much admired, and some varieties are produced at Leeds, and
finished the natural colour of the wool. In the west of England flannels aie madc^
but not extensively, and in Ireland a few varieties of low flannels and coatings^ called
Oalwavs, are manufactured from Irish grown wool.
FLAT RODS. In mining, a series of rods for communicating motion from the
ennne, horizontally, to the pumps or other machinery in a distant shaft
FLAX (Latin, linum; French^ Un; Italian and Spanish, tino; Portuguese. luAo;
German ^cA«; Dutch fk£u)fihe LmumvntatisnMtm, a plant of the class Pentandroi,
order Pentagynia, in the system of Linnaeus, and the type of the order Lmaeese, in
the natural system of Botany, largely cultivated for its fibre and seed, and, next to
cotton, the most extensiTely used raw material for textile manufiieture in the vegetable
kingdom. This plant was primarily a native of Asia, and was introduced at an eariy
period, into Europe. Frequent mention is made of it in scripture history, as grown
both in Palestine and in Egypt, as well as of the fabrics manufSictured from its fibre.
It was probably introduced into Europe by the Phmnician traders, or the Onck
colonists of Egypt and Syria. Homer idludes to the linen manufacture of Greece.
At the present day, the flax plant is grown for flbre alone, for seed alone, or fbr
both products together, in many countries of the eastern, and in some of the westen
hemisphere. For seed alone, in Hindostan, Tm^ey, and the United Statesof America;
for fibre and seed in Russia, Belgium, Holland, France, Germany, Scandinavia, Italy,
Switzerland, the Iberian Peninsula, Great Britain, and Egypt ; m Ireland, chiefly for
tiie fibre, without utilising the seed.
The average annual production of fibre, in the chief countries where fiaz is gnnvnt
is as follows: —
Tooa.
Russia ---. 180,000
France -.-.--.. 48,000
Belgium 18,000
Holland 9,000
Austria 60,000
Prussia ... .... 32,000
Ireland ........ 85,000
Egypt 10,000
and adding all other countries, we may estimate the entire annual weight of fibre
produced Uiroughout the world, at 400,000 tons.
The quantity of seed may be taken at nearly 2,000,000 of quarters. At the
average value of fibre and seed, the annual production in all countries, of the former,
may be given in value at 2O,0O0,0O0iL, and of the latter at 5,000,000/L, making in all,
25,000,000A as the worth of the raw produce, before its conversion into woven frbries
and feeding stufh.
The flax plant has a single slender stem, varying from 2 to 4 feet in height, ae-
cording to the nature of the soU and the season, with the difference of climate, sad
mode of culture. It has lanceolate, sessile leaves, of a rich green colour, and bianchei
out, at the top, into two or more small stems, each of 2 or 3 inches in leogtii,
and bearing light blue flowers, succeeded by globular capsules, pointed at the apex,
and bearing 8 to 10 seeds of a reddish brown, when ripe. The stem of the {dsot
consists of an inner part, or core, sometimes hollow, but more frequently solid, con-
posed of ligneous matter, surrounded with a bark of flbres, which are united to each
other by a gam, the whole being sheathed in a fine epidermis. The plant arrivei st
maturity in 14 or 15 weeks after the seed is sown. It has then changed to a pale
yellow or straw colour, and the seeds have become brown. The usual period of
sowing, in European countries, is from March to May, although in some parts of the
Continent the seed is put in the ground in autumn, but in this case nothing is gained,
as the plant becomes mature very little earlier than when the sowing is done ia
FLAX. 227
spring. It is grown on a wide mnge of miJs, sandy, oalcazvoof, dav, loam, peatv, &e.,
bat that best adapted to it is» either a deep, fiiable, clay loam, or the aUuTial deposit
of riTers. whether along their banks, their deltas, or where reclaimed from the sea,
aa in the case of the polders of Holland. Deep tillage, good drainage, and repeated
polvensation of the soil, are very requinte. Tlie preparations for the crop are hegnn
in winter, by ploughing the surface, and toming it up to the action of frost : tney
are completed in spring, by plowing and harrowing. The seed is sown at the rate olf
a| bnsbels per statute acre, the bttX season being April. In the British Isles,
Belginm, and Holland, the fityonrite seed is obtained from Russia, Riga being the
port of diipment Dutch seed is also extensiyely in nse in Ireland, in the heayier
class of soOs. American is also occasionally used in Ireland, and a good deal of
home ^own seed — the first year*s growth from Riga seed (one year from the barrel),
which is considered quite equal to the parent 1^ manure is used in Ireland, but in
Belgiom and France, rape ci^e dissolyed in urine is considered yery usefuL The
seed is sown broadcast, and the soil is afterwards rolled. When the plant is a few
inches high, weeds are careftilly remoyed, and no further attention is necessary until
the season of pulling. Flax is not cut with the scythe or sickle, but is pulled up by
the roots. About the middle of August it is generally ready for pnlliuff, in the British
Islands, but in Belgium and France, it is in a fit state S to 8 weeks earlier.
The alter treatment yaries in different countries. In Russia, part of Belgium and
Holland, and in France, the plant after being pulled, is dried in the sun, being set up
on the root end in two thin rows, the top interlacing in the form of the letter Vin-
Terted. The sun and air soon thoroughly dry the stems, and they are then made
into sbeayes, and the seed afterwards beaten o£El The stems are steeped subsequently.
Another mode, in general use in Ireland and in part of Flanders, is to steep Om green
stems immediately after they are pulled. In Flanders, the seed is inyanably separated
frtmi the stems before the latter are immersed in water. In Ireland, although thb
is practised to some ext^t, yet the great bulk of the flax crop is put in the water at
once, with the seed capsules attached, and consequently there is a yery considerable
annual loss to the country, by this waste of a most yiduable product of the plant
In the Walloon country of Belgium, in its eastern proTinces, and in the greater part
of Germany, dew-retting is practised. That is, in place of immersinff the stems in
water, they are spread thinly on short grass, and the action of the dews and rains
ultimately effect what inmiersion in a running stream or pool accomplishes in a much
shorter tmie, namely, the decomposition of the gum which binds the fibres to the stem
and to each other. Fibre obtained by this method is, howerer, of very inferior
quality and colour.
If the fibre of flax be separated from the stem, without the decomposition of this
matter, it is found to be loaded with impurities, which are got rid of afterwards in the
wet^pinning, the boiling of the yarn, the subjection of the woyen fabric to the action
of an alkaline lye, and the action of the atmosphere, — of rains and of alternate dippings
in water, acidulated with sulphuric acid, and of a solution of chloxide of lime, which
are all required to perfect the bleaching. The great object, therefore, is to obtain the
fibre as nearly tree from all foreign substances as possible, and, consequently, the
mechanical separation of it firom uie woody pith of ^e stem is not to be recom-
At yarious periods attempts have been made to prepare flax fibre without steeping.
Weak acids, solutions of caustic potarii, and of soda, soap, lye, and lime, haye all been
tried, but haye all been found objectionable. In 1815 Hr. Lee brought before ^ the
trustees of the linen and hempen manufactures of Ireland " his system of separating
the fibte without steeping. He alleged that a large yield was thus obtained, th^t the
colouring matter could afterwards be discharged by the most simple means, and that
the fibre possessed greater strength. But ft was found that the system was practi-
cally worUiIess. In 1816, Mr. Pollard, of Manchester, brought forward a plan of the
same nature, and proposed to make an article from flax, which could he spun on
cotton machinery. This also fell to the ground. In France and Belgium, at different
periods, similar projects were found equally impracticable. In 1850, and again in
1857, Mr- Doolan reyiyed the same, but the same fktal objections preyented the success
of the systeoL The fibre was loaded with impurities, and the apparently larger
jield oyer steeped fibre, consisted solely of these yery impurities, which had to be
got rid of in the after processes of manufacture. At the same time it must be recog^
uised that the ** dry separated " fibre can be rendered useful for one class of manu-
frietnres, yii., those where no bleaching is necessary, and its great strength Lb here
an object For ropes, rick-^oyers, tarpauluis, railway -waggon coyers, &&,, where
ptt4di or tar are used, and preyent ihe decomjposing action of moisture and of atmo*
spheric changes, this mode of obtabiing flax fibre is highly usefhL
The immersion of the fiax stems in water, either as pulled ftill of lapi or after
228 FLAX.
drying, appears, as jet, to be ihe best mode of effectiug die deeompositio& cf the
gam, and obtainiog the fibre pure, or nearly so. The water most sattable for Uiis
purpose is that obtained from sarlace drainage, springs generally holding more or
less of mineral matters in solution. Spring-water from a cilcareoas soil is pecolisrlj
tmsoitable, the carbonate of lime which it contains being adverse to the pidieftctive
fermentation of the vegetable extractive. In Bassia, mnch of the flax grovn ii
steeped in lakes. In Holland, it is always steeped in pools filled with the Btuhoe
drainage. In France and Belgium, it is either steeped in pools or rivers. In Eng-
land and Ireland, generally in pools, though occasionally in rivers. The most ode-
brated steep-water in the world is the river Lys, which rises in the north of Fnoee,
and flows through the west of Belgium, joining the Escant at Ghent Althou^ die
water of this stream has been analysed, chemists have not been able to discover why it
should be so peculiarly favourable to the steeping of flax. All along its course flu
is steeped. The trade is in the hands of &ctors, who purchase the dried stems fnm
the growers, and undertake all the after processes, selling the fibre to merchants vbes
it has been prepared for sale. The i4>paratus in use consists of wooden crates, 12 fieet
long, 8 wide, and 3 deep. The sheaves of flax-straw are placed erect in the entei^
and the root ends of one are tied to the top ends of another, to secure nnlfomiity of
packing. The crate, when filled, is carried into the river, and anchored there, the
upper part being sunk by the weight of stones, 6 inches underneath the surftce. The
period of steeping begins in May, and ends about September. The prerioos yeai^f
crop is thus steeped, having lain over in the state of dried straw during the vinter.
All the flax thus treated produces fibre of a yellowish white colour, very soft ind
lustrous, with very finely divided filaments, and strong. From it almost exclttsively
is made cambric, the finest shirtings, and damask table-linen. It is a strange &ct
that flax straw is brought to the Lys, from a great distance, and even from Hollaod, ai
no other water has yet been found to give such good fibre.
In 1847 a new system of steeping was introduced in Ireland, by Mr. Schenek, of
!New York. It had been successMIy tried in America on hemp, and the inveotor
crossed the Atlantic to try its efficacy on flax. His plan consisted in hastening the
putrefoctive fermentation of the vegetable extractive by artificially raising the tein-
perature of the water to 9QP Fahrenheit By this means instead of an uncertiin
period of seven to twenty-one days being required for the steep, according to the state
of the weather and the temperature of tne atmosphere, the flax was retted uniformly
in sixty hours. The flax straw, after the separation of the seed, is placed in wooden
or brick vats, and the heat is communicated by forcing steam into a coil of iron or
leaden pipes, placed under a &lse bottom perforated with holes.
The annexed plan (Jig. 795) of a retting on Schenck's system, capable of consunung
annually the produce of 400 acres of flax, and employmg, in idl the operations «
seeding, steeping, drying, and scutching, 30 men and 55 girls and boys, ot an aggre-
gate of 85 persons, will give an idea of the arrangements. The seeding-boose
requires to be of large sixe, as flax straw is a bulky article. It is on the ground floor,
for the convenience of carting in the flax. The loft above it is used for cleaning asd
storing the seed. The vat and spreading-rooms are in a building of one story oolji
built with a vaulted roof resting on pillars. That part of the roof which is over
the vats has lower windows to aid tiie escape of the vapours from the vats. The
drying sheds at the top of the plan are on an open space, well exposed to the wini
and fifty or sixty feet apart xhe hot air rooms or desiccating house are fire-prooC
each room capable of containing the flax turned out in one day's work. The sestch
mill, with engine and boiler-house, complete the plan.
The advantages of this system were so manifest that it was speedily adopted in
many parts of tiie Unit^ Kmgdom and of the Continent It was found, however, to
have some defects. The small quantity of water soon became thoroughly saturated
with the products of decomposition, and the fibre of the flax, when dri^ was, eooae-
quently, found loaded with a yellow powder, offensive to the smell, causing inoon*
vemence in the preparing and spinning, and worse still, acting pngodicially on the
quality of the fibre itself, rendering it harsh and dry.
To obviate these defects, Mr. Pownall, of London, conceived the idea of preoing
the flax straw, immediately when taken out of the steep, between a pair of smooth
cast-iron cylinders, while, at the same time, a stream of water played upon the roUaa
By these means the foul water of the vat is pressed out of the flax stems, which are
flattened and bruised, thus tending to aid tlie separation of the bundles of fibres into
minute filaments, while the stream of water effectually washed away all remaining
impurities.
It has recentiy been found that better fibre can be obtained by reducing the tem-
perature and extending the time of steeping. The most perfect adaptation of Schenck*s
system is at the rettery of M. Auguste Scrive, near Lille, and fg, 796 is a repre-
280 FLAX.
fimr iochea thick a, ealebing the tops oo tlie whole length of tsch row of bmHa,
Then Btri[i« of wood an kept Arm by crou iron bolder* a, weiired by iron ben r,
fimened lo pieces of wood d. worked into the side wills of the Unk, leaTing e sot&M
of font iHchesdeep of water over the lop of the flat. When the tank has been SIH
with cold water ihrongh the wooden shoot e, the whole is rapidlj heated to 'iV
Fahrenheit, by means o( steam pipes coiled under the ToUe bottom. A secoDdofn
ahoot T, carries heated water at 90° to diacharge on the snrtaoe, beiide* two closri
pipes o a, one of which brings hoc water of the same temperatare, and the oiker caU
waler. When fenaentnlioa seta in, which la ordinarily in eight boara, tbe pipe, ■•
well aa the shoot of water at 90°, isaet at pU;. The first to create acootlnaalcnnnl
of fresh water through the mass of &Bi, clearing off the products of dceompotiliai.
and bringiog them to tbe surface ; the second to drire this foul water to the ^eningt
B a, where it is discharged by the overflow. The two pipes with heated and cold
water going to Che bottom of the tank, aa well ai the two shoots containnig coU ul
hot water, lo go to the lurfsce, are also made use of to equalise the temperatare daring
the whole opemtioo, which ia ascertained by the use of a thermometer in tbe sqjoui
wooden box J J. The steeping of coarse straw requires -16 to 46 hoars, nedisa
qnalitiea SO to 60 houra, and the finer deacriptiona SO to 73 houra. The " wet roll-
ing " between cylinders after the ateep ia accompanied by a shower of water at li',
not on the flax but on the top of the cylindera. This removes the remaining inpo-
Titles, and prepare! the straw for being easily dried. The healed water may Iw ob-
tained from the watte water of a spinning-mill, or from a condensing ateam-eDgint
Flai steeped by Schenck's system ia dried in various ways. I^me retten bin
drying honses with heated air, others set np the flax loosely on the root ei>d, in theUd,
or spread it thinly on the grass, while olhera, again, claan it between two slndn
pieces of wood about a yard in length, and hang theae np in a building open tt lb
aides, so that a current of atmoapfaeric air ia constantly passing throogh.
In 1S52 another mode of retting fiai was introduced by Mr. Watt, of GlaigoT.
Inttead of immersing the stems in water, he subjected them to the action of Bom.
Bqnare iron chambers were employed, in which Che fiai straw waa packed. The door
by which It was introduced waa Chen ^Ceoed by bolts or nnta, and steam was dm
drJTen in. The steam penetrated the stenu of the flax, and being partially eondensFd
on tbe top and aides of the iron chamber, a conitaot drip of water, lukewarm, fell ■)■>
tbeOax. In twelve to foDTteen honra tbe stems were removedjaod, after being drlol,
■ ■ ■ 7«7 "
FLAX.
231
diis method wu of a greyish oolonr, aDd was at fint well thought of by mannftctaTert ;
bat, in the end, on more extended trials it was fbond to possess several defects, and
"Watt's system is not now carried out
Another system of treating flax was introdoced by 31 Clanssen, a Belgian, and for
some time it attracted moch attention. He separated the fibre fh>m the stem without
steeping, snd then, by the employment of acids and alkalies, he got rid of the Tegetable
extractiTe and other impnrities, and produced a fibrous mass stron^y resembling cotton.
He professed to make an article capable of bemg spun with cotton or wooL The
higher value of flax fibre, howcTcr, was a great obstacle, and at present the only use
maile of his process is to oouTert scntching tow — the reftise flax fibre— into an article
to be spun with wool, and even this is practised to but a Tery small extent
Messrs. Burton and Pye's patent (Jig, 797) is a modification of the hot water steepw
By this process the flax straw, after the seed is remoTed, is psssed through a machine
composed of plain and crimping rollers, by the combined action of which the woody
part is rendered essily separable from the fibre. The latter is then placed in a rat,
holding about a ton, which is subsequently filled with cold water. This vat has a per*
Ibnted ftlse bottom, under which stesm, with a pressure of 50 lbs. to an inch, is iup
798
trodnced and disseminated by perforated tubes. Another tube conTe}'s mto the vat a
oold mixtnre of fhUer's earth in water. The introduction of the mixture and the steam
232 FLAX.
is oontinoed until the liquid in the yat reaches 80^ Fahrenheit The flax Temaias ia
it at this temperatare for thirty honrs, vhen the sorfaee of the liquid is covered with i
sapoDaceons fVoth. Then an apparatus of cross bars of wood, closely fitting into the
interior of the vat, and pressed by two powerful screws, expresses the impnrities from
the fibre. The supply of the faller^s earth is stopped, and cold water is alone sup-
plied with the steam, so regulated that the temperature is by degrees raised to 150^,
the pressure being continued until the water appears firee from impurities. The water
is then withdrawn from the vat through a yaWe in the bottom, and a pressure equal to
200 tons is applied to the mass of the flax. It remains under this pressure for foor hoars,
when it is half dry. It is then taken out and dried in sheds open at the sides to the
air. The fibre produced by Mr. Pye*s method appears of good quality and strong,
hut the system has not as yet been carried out on a sufficiently large scale to admit of
a decided opinion on its merits.
The same may be said of the plan of M. Terwanfue, of Lille, who employs hot
water at a temperature of 15^ to 17° centigrade, 60° Fahr., in which chalk and char-
coal have been placed. His process requires seventy- two hours on the average, sod
he employs brick tanks. The water is, as in all the preceding cases, heated by iteam.
Before leaving the subject of steeping, reference may be made to a process patented
by Mr. F. M. Jennings, of Cork, by means of which coarse flax fibre is rendered
capable of being subdivided into minute filaments, or, in other words, made fine.
While the fibre of cotton is incapable of subdivision, that of fiax, as viewed throagh
the microscope, is seen to consist of a bundle of extremely delicate filaments adhering
together, so that fine and coarse fiax are really relative terms. Mr. Jennings throws
down upon the flax fibre, as it appears in commerce, a small quantity of oil, say half
an ounce to the pound of fibre. He effects this by boiling the fibre in an alkaline sotp
lye, washing wiUi water, and then boiling in water slightly acidulated vrith pyrolig-
neons acid, which decomposes the soap and leaves its ^tty constituent on the fibre.
It is afterwards washed once more, and is then found to be soft and silky, and the
coarse fibres capable of being readily separated on the hackle, while the strength is
not apparently reduced. There is also a greater facility in the bleaching of the lisea
made from flax fibre so treated, and less loss in weight m the bleaching process.
While some of the inventions referred to for hastening and equalising the time of
steeping are being carried out to a considerable extent, and promise well, when broagfat
to a greater degree of perfection by experience in practical working, to be yet more
largely employed, the great mass of the flax grown throughout the globe is steeped in
pools, rivers, or lakes. It will, therefore, be most advisable to follow the processes, as
practised by the growers or fiictors.
When the flax has been sufficiently retted, i. e. when on taking a few stalks cot of
the water the flbre can be readily separated by the fingers along its entire length from
the woody interior, it is removed from the water, and placed to drain on the banks of
the pool or river. It is then taken to a closely shorn grass-field or old pasture land,
and spread thinly and evenly on the ground. In Flfuiders, however, the system of
drying is somewhat different Instead of being spread flat on the ground, the sheaves
are divided into four portions, and these are set upright in capeUes, t. e., the butt ends
are spread widely out in a circle on the ground, and the tops are kept doee together.
By this means the sun and air soon dry the flax. . When thoroughly dried it is tied
up in sheaves, and after remaining a few days in the usual form of a grain stack, tt is
ricked. In this state it may remain for years without the fibre being deteriorated.
The next process is termed scutching (French, teitlage\ and is intended to separate
the fibre from the woody matter of the stem, and thus to make it fit for the spinner.
The first part of this process is to bruise the stems thoroughly, so that whUe the fibre,
from its tenacity, is intact, the brittle woody part is flattened and broken in such a
manner as to admit of its easily being beaten off by the action of the scutch-blade or
scutch-mill. In most countries the bruising is done by hand. In Flanders and France
the flax straw is first laid flat on the ground, the sheaf being untied and spread thinly,
and^ the workman, placing his foot upon it, beats it with an instrument called a maH,
having a curved handle and a heavy square indented mallet, >S^. 799.
The next part of the process is to give the flax repeated blows in a machine termed
a hraci or braquey Jig, 800. This is generally made of wood, but sometimes of iron,
and consists of two rows of grooves t t, the upper one moving on a pivot at the
socket 8.^ A stout pole p runs firom end to end of the upper row of teeth. The latter
are wedge-shaped, 4} inch deep, \^ inches thick at top, and 33^ inches long from the
head h to the socket s. The head weighs about 8 lbs. and is 10 inches long, and l{
inches thick. The lower row of teeth consists of four, while the upper is three, fitting
into the interstices. The best wood for the machine is that of the apple-tree.
Next comes the scutching proper, still following the Belgian, French, and Dutch
method of hand-work. After the flax has been bruised by Uie mailt and crushed by
pine or beecb, mbonl 4 feet Ugh, aod nther more tliu a foot broad, aboot } inch
thick, ii Used in a woadm aola b. 3 foet bum thii sole i* a cnl b the wood of the
Dpright plank, about 1) to S inchei wide. Thia cat lerTca for tbe iotroduction of a
bandfiilof the flax ittaw, brniied aa before deacribed, and the workman hohUng it thne-
finnth* eipoaed tfaroagh the ilit, beati it with a tool called the (calcb-blade,^. SOS.
It ia made of waloot wood, and ia Terr loogb and Qeiible. In Ireland the ■jilera
of anitching b; band ia Terr i^de, and prevaila chieSf in the westera couatiei. A
brake timilar to that of Belgiam is emplof ed, bat ioitead of ibe Belgian tcaich tooJ,
a nide iDitrnment ia empio}'ed, generallj of ash- wood, in the farm of a awonL blade.
It most be stated that the ijrnein of handacntcbing is onl^ lo be recommended where
the qnalitj of tbe flai fibre ia so niperior aa to reader economy in waite of primarj
importance, or else where the wagea of labour are M low, aa to render tbe power of
nucbiner7 of little conaequence, aa regarda economy. Bnt, where wages arehirii,
and flax of medinm or low qnalily, there ia no qneailoD tbat macbiDe-scntchinv is the
moat advisable, and the moat ecooomicaL Tbis has been especially recognised in
Ireland, where in 18S7. 1037 watch mills were in operation, when the growers sent
their crops to be prepared for market, at a reasonable rata, mnch leas than hand-
scotching would haTC coat Scnich mills have been introduced with adTantage into
Ruana, Pnisaia, Austria, Denmark, Holland, Belgium, France, Italy, and Egypt
In Ireland, althongh in seieral districts Sax is scutched by hand, machine or mill
seatcbing ha^been for more tban half a century in operation. As in the hand-
scotching, the operation consists of two processes: first, the bruising of the stems,
and aecoDdly, the beating away of the woody parts fVom the Bbre, The original
334 FLAX.
tyttem ofbrniuDg ii nil! ttrj general It eon^fU of ■ fct of three imooUi wmAta
Taller*, one nndemrath and tbe tiro others Above it, pir&Uel to e>ch other, vA (bc of
them horiiontal la the lover roller. The labourer siti opposite the lower roller, ai
iosartsB handful of Sax atrav between the latter and the upper one, which iahorixintil
to i(. The flax being drawn in and bruiaed between tlie»e, pauea np between tbe lire
upper rollers, and reappears at tbe oalaide. It u s^n put through, once or twiet,
according Ui iCi thickueu, or to its being more or less steeped, and the Bbre, Cfaie-
qucnlly, more or leu easllj ft'eed from the ligneana part. Tbe scutching; appanlni
consists of a vooden shaft, to which are attached, at intervals, like radii of a ciide,
abort anns, io which are nailed the tlacit, which are parallelogram ahaped tdadei ct
hard wood, with the edges partially sharpened. The laboorer stands beride an ap-
right wooden plank, very similar to that figured iu the description of tbe Belgiia
hand-scutching spparstns, and through just such a slit exposes one half of the haiidfid
of bruised flax -straw to the action of the stocks, which rerolie with rapidity akag
with the shaft, and strike [he flax straw, beating off tbe ligneous mailer, and leaiiij
the fibre clear. When the end exposed to the nockg is cleaned, the workman tant
the handful and exposes the other end. It is usual to have a set of either tvo or
three men, at as many diSerent stands, and instead of each thoroughly clearing ea
the handful of flax, he only partialiy does so -. tlie second then takes it ap and fiiiHbcs
it; or, if there be three in the set, be does not quite clean it, bat baodi it over to the
third to do to. In the latter case, the first workman is called the bufftr, the seca^
the niddUr, and the third the Jaiiiher. The motive potrer in these seuteh-Dilli a
generally water ; in some cases they are wind-mills, and in a f^w iastanees they an
driyen by horses. Latterly, the use of sleam-eDgiues has conuderaUy increased, m
being more to be depended apon than water, which frequently liula in a dry •»■&
80a
It has been foond thai the woody waste produced in ibe scutching, is quite snIEneit
j^iel for the boiler, wilhout its being necessary to purchase coal or peat, and itiiswux
had hitherto been applied to no useful purpose, being with the greatest difficulty it-
composable for manure.
Tlie first improvement od this old scutch-mill apparatus was (he introdnetioD, b;
Messrs. MaeAdam Brothers, of Belfast, of a machine fbr bruising the flax stn*.
prior to steeping, and It has since been extensively employed, with Tery satiiftsKfl
results. It consists of a serie* of fluted rollers, running vertically on each alher, iw
flniings varying in width, the widest let being Ibe first through which the flax itts*
FLAX
23£
ptnmL, and ike otbm dimlDithing in vidib, until the Amm li Hie tut WUlc eetiag
■tronglj OB the Ugneoni mattrr, mt the Mme time braiiiDg end crimping it, and re-
ducing it almon to powder, it doei not iiijim or diMmnge the fibres. One brekking
machine of tbie connmetioa ii capable of inppljiiig 13 eonlcbing standi of the ordi-
nary milL It is attended by two bojs, one to fred the flsx-straw inio the machine,
lij iDeans of a feeding table, and Ihe other to remore it at the opposite eitr«mit;.
Once passing throngli the maehine is quite snfflcient to piepere the flax ttmv
a drivi
it is<
Figt
It hsring been foond that many diaadTanlagee Tcre iaherent in the old MBtch*
mill, saTeTiLl person! bare set themselves to work to aapply a machine «bich wonid
redace the cost of labonr, obriale tbe necexniy of obtaunng abilled workmen, and
diminiab the greet w»Me of fibre, which wti bat loo fyeqoent In the ordinary milL
Among the most sacoessftil of tbeae scntching-machines, is an invention of Hr.
Mae-Bride, of Armagh, Ireland, J^t. S(M, 805. It oonuati of a cast-irm (hunc, at
tmtHi end «f which ii a compartment, enclosbg a double set of beaters, of peenlinr
constracticm, which rcroWe rapidly in a contrary direction, striking alternately on
I ach aide of the flax, a* it is submitted to their action, and dioronghly remoring the
woody part, which fnlls down in dust into a pit or hollow onder the machine. In
order to Carry the flax gradnallj through the machine, and present it in a proper
Tusnnrr to the beaten, in snccession, an ccdlesa double rope is introduced, carried in
tbe hollow of a large grooved wheel, in which it is kept tight, bj mean! of tension
Tcights. The Bas-straw, made into handfnls, is introduced at A, onder the doable
rope, at one end of the machine, and is at once grasped by it Snnlj, rather ibore iti
middle, and carried along ilowly, by the movement of the grooved wheel, nntil ii
'' " ' ' rnwards, th ._--.--■_.,- -.-. .... ,..
enters, hanging downwi
s, the compartment b, ci
D of the beaten, la cleaned out, and the rope, passiuR 01
abort way Ikrther, arriTct at a point where a second grooved wheel is revolving, ftir-
niahed with ropes in like manner, but arranged at a rather lower level. By s limple
arrangement, the flax is here transferred from one set of ropes to the other, the
second set grmsping it near its lowest end, thns leaving all the nncleaned part, or upper
halt, ready to be icuEehcd. The second wheel moves on, and carries the flSK to-
286 FLAX.
wards the compartment containing the second set of beaten, cleaning nil the vppc'
portion of the flax. It then issues out at d, cleaned throoghoat, and is receiTed by a
person placed there for that purpose, vho makes it up into the asual package for sale,
le^lbs. A constant succession of similar handAiIs of flax-straw are thus kept pass-
ing through the machine without interruption, b e are the beaters, f r are two cones,
carrying a leather band, which gives the motion to the ropes, or carrying appnrato^
By shifting the position of this band towards one end or the other of the cones, the
speed of the carrying-ropes may be yaried at pleasure, so as to keep the flax a longer
or shorter time under the beaters. Some kinds of flax require more scntehing than
others, a o are the driving pulleys, for giving motion to the machine, by memoM of a
band from motive power, which may be steam, water, wind, or horses. Each pair of
pullers drives one set of beaters separately from the other set, and hence, if requisite
to drive one set flaster than the other, which is sometimes the case when the t<ip end
of the flax is hard to dean, this is easily done by using a similar pulley on the wM*^h"»f,
or a larger drum on the driving shaft, h h are the tension weights and lewen fiir
keeping U^ht the carrying-ropes. J J are bearers of wood for carrying the ft»me of
the machme. k k are pits underneath the compartments containing the beaten,
and are for receiving the woody dust as it falls from the flax-straw. Tlie maehiae
occupies a space of 11| feet, by 10 feet, but some space is required round it for
handling the flax. The height of the machine is 6^ feet The power required is
three-horse.
M. Mertens, of Gheel, Belgium, has invented a scutching-machine, which merits
notice. It is portable and cheap, and requires the attendance of only boys or ^r]s,to
put the flax -straw in and take the scatched-fibre out The action is something similar
to that of the Irish scutch-mill, but the bruised flax-straw is placed in iron claaps, one
end being first cleaned out, and then the clasps opened, the flax-straw reversed, and a
second insertion in the machine clears out the other end.
Messrs. Rowan, of Belfast, have very recently introduced a scutching maoiiitf
whose action differs fh>m all hitherto in use. The flax-straw is not previously
bmised, but is at once fastened in iron clasps, which are placed in a slide, the aedoa
of the machine carrying them on along one side, while two parallel bsira of iron,
toothed, comb the straw and separate the woody part from the fibre. The first
portion of these bars have coarse teeth, and the teeth become closer by degrees up to
the end of the slide. There a workman or boy takes out the clasps, unscrews the
nuts fastening them, and reverses the position of the straw, so that the portion not
previously subjected to the action of the machine is now presented to it, while that
already cleaned out is untouched. The machine is double, Le. has two sides of
combs, each capable of containing twelve of the clasps, and each cleaning out one
end of the flax-straw. Hence, aner the workman or boy has unclasped the half-
cleaned straw, turned it upside down, and presented the undeaned end to the other
side of the machine, the same action of combing, already described, clears out that
end thoroughly, and by the time the progressive movement of the mechanism brings
the slide to the extreme end, the flax fibre appears tree fh>m woody refuse, and in a
fit state for market It is then unclasped and made up into bundles.
There have been a great number of other scutching machines invented, hat it is
not necessary to particularise them.
In the operation of scutching, however carefully it may be done by hand or by
machine, there occurs more or less wast^ i. e. the beating of the flax-straw, in order
to separate the marketable fibre from the useless wood, caoses a portion of the former
to be torn off in short filaments mingled with the wood, and this torn fibre is veij
much less viduable than the long filimients when finally cleared out In general, it
will not average more than an eighth or a tenth of the value of the long fibre. It is
termed acutcfung-tow or codilla, and when properly cleaned is dry-span K>r yams em-
ployed in making coarse sacking, tarpaulins, &c. Being very much mixed with the
woody-matter of the fiax-stems, it is necessary to get rid of the latter before the
scutching-tow can be spun into yam. To accomplish this, shaking by hand is the
first process, and subsequently the stuff is put into a woody machine termed a ** devil,"
in which, by a mechanism something resembling the shakers in a threshing machine*
the woody particles and dust are got rid ofl The tow is sorted into different quali-
ties, and, in some cases, it is kackkd before being sold. In France and Belgium, it is
chiefly retained at home, spun by hand, and woven into sach fiibrics as coarse
trowsers and shirts, for the labouring classes, aprons, table-covers, &c. 3tc What is
produced in Russia, is partly used for similar purposes among the serfs, hot the great
mass iB exported. Great Britain and Ireland being the chief mart, and Dundee espe-
cially.
The great aim in all the different methods of scutching, has been to obtain the
largest possible yield of long flbre from the flax-straw, and to waste as little as pos*
FLAX. 237
tlble in seatchlng-tow. The French and Flemish sjstem of band-wntchuig is most
snooeflsfhl in this respect, bat as the quality of fibre there produced is very much
finer, and consequently more yaluable than lil others, the additional expense of hand-
labour is compensated by the larger yield of long fibre ; whereas, in Ireland, the fibre
being generally coarser and less yaluable, occupying an intermediate place between
the Flemish and Russian, the cheapnew of mill-scutching turns the scale, and, except
in remote districts, it is now universaL In Egypt, until some fifteen years ago, the
method of scutching was of the most primitive form. The fellahs, after steeping
their flax in the Nile, and drying it on the banks, proceeded to clean out the fibre, by
first beating the straw between two flat stones, and then strikbg it against a wooden
posL Mehemet Ali and his successors, however, introduced Irish scutch mills, driven
by steam-power, and since then a marked Improvement has taken place in the state
in which Egyptian flax has been broup^bt to market It may be interestiuff to note
here, that in Uie early period of Egjrptian civilisation, the dwellers by the Nile were
able to manufacture cambrics of a finer texture than the most finished modem mecha-
nism can produce, — as is evidenced by the cerecloths wrapping the mummies, and
that firom a fibre so coarse in comparison to European flax, that while the latter may
be span by machinery to 800 or 400 leas, and by hand to 1200 leas, the former can-
not be put higher than 40 to 50 leas, and rarely even to that
In the scutching operation, three several matters are obtained from the flax stems.
The first is the fibre, which is the primary object, and which is the really valuable
portion, that known as ** flax " in commerce. The second is the woody reftise of the
stems, hitherto applied to no other use than as fuel, or occasionally in Ireland as a
covering for cuttings of potatoes, when planted, to protect them from frost Mr. Pye,
of Ipswich, however, proposes to make it available as an auxiliary food for
cattle, having the authority of Professor Way that a sample analysed by him yielded
7*02 per cent of oil and fiitty matter; 7*93 of albuminous matter (containing 1*25
nitrogen), and 26*29 starch, gum, sugar, &c. He (Mr. Pye) recommended its use
for feeding live stock, in conjunction with ground oats or other farinaceous food.
Professor Hodges, nevertheless, in analysing another sample of this ground ligneous
matter, gave quite a different result, his estimate of the nutritive constituents being
as follows: — ^ nitrogenised flesh-forming matters, 3*23 per cent ; oil and fktty matters,
2-91 ; gum and soluble matters, 14*66 ; and he compared this with the average results
of seven analyses of oil cake, giving nitrogenised matters, 28*47; fittty matters,
12*90 ; gum and other soluble matters, 39*01.
The uiird portion separated by the scutching process is termed ** acutching-tow^ in
Ireland ; in Russia and Prussia,** cocfiOa ; " in France and Belgium, ** etouppe de teiUage^
describel above. These branches of the trade consume annually many thousand tons,
imported chiefly into Scotland, from Russia and Prussia. In France, Belgium, and Hol-
land, tibe cedilla or scutching tow is chiefly retained by the growers or factors at home,
for a domestic manufacture of similar goods, and of coarse blouses and trowsers. It has
also been employed for conversion, by Claussen's process, into a finely divided mass of
fibres, capable of being mixed with wool and spun along with it into yam, the fabric
made from this yam being chiefly hose.
Before proce^in^ to treat of Uie processes to which flax fibre is subjected subse-
quent to scutching, it may be well to glance at the uses to which the seed is applied.
This valuable pr^uct of the plant furnishes two articles of much utility, and of very
extensive use, — the oil and the cake. When the seed has been separated, dried and
freshed out, it is either sold again for sowing or for conversion into cake and oil.
Of course the former purpose only consumes a small proportion of the seed produced
throogfaout the world, and in many countries it is not of a quality suitable to the chief
flax -growing localities. Thus, while northern Russia, Germany, the Low Countries,
and France either export seed for sowing, or consume their own produpe to a considerable
extent for tins purpose ; the southern provinces of Russia, the states along the Medi-
terranean, Egypt, Turkey, Greece, and the East Indies, while large exporters of seed
for cmshing, cannot sell any for sowing. The supply of the seed crushers of the
United Kingdom is more largely obtained fh>m Russia and Hindoostan than from any
other countries. The entire annual import of seed into the British Islands averages
600,000 to 800,000 quarters, value between a million and a half and two millions
sterling.' The conversion of flax seed into oil and cake is carried out by different
methods. In France, Belgium, Holland, and the north of Europe generally, where
a large quantity is crushed, the apparatus employed is very simple and yet very effec-
tive. Lille, in France, Courtrai and Ghent, in Belgium, Neuss, in Prussia, and the
jyrovince of Holstein are the great seats of this maniSacture. See Linseed.
The seed is pounded in a kind of wooden mortars, cut out of solid timber, and at
the bottom lined with thick copper. By means of a revolving shaft, furnished
with pTojecUng notches of wood, beams of oak 20 feet high, the ends shod with
238 FLAX.
chaanelled iron, are alternatelj raised np and let fall into the mortani vbere, u i
short time, thej convert the seed into a pulpy mass. When sufficiently poaaded, Out
is then remored and put into woollen bags, which are then wrapped up ia s leitfaera
case lined with a hard twisted web of horse-hair, covering both sides snd endif but
open at the edges. These are then ready to be pressed, and for this pnrpoM sre
packed perpendicularly in an iron receptacle, narrow at the bottom, and vidaiig
towards the top. Packings of metal are then put in, and in the centre of the hkp 'n
inserted a beech wedge. A beam similar to that employed in pounding the leed ii
then set in motion, and at each descending stroke it driyes the wedge in tighter, thm
squeezing the bags of seed against the iron sides of the press. When the wedge hti
been driven home, another is introduced and battered by the beam, until it vill dhre
DO fkrther. At the bottom of the press are holes through which the oil thni prased
out of the seed runs into a receptacle beneath. In order to loosen the wed^ ud
admit of the bags baing removed from the press, a wedge of a different fonn, wide at
bottom and narrow at to^,and already a fixture in the press, but raised np and &itened
by a rope during the driving of the other wedges, is released from the rope, snd another
beam drives it home, thus partially starting the differently constructed wedga ud
loosening the mass. The bags with the pressed seed are then taken cot, and the
latter, having lost the greater part of its oil while subjected to so considerable a
pressure is found in a thin hardish cake, taking the form of the leathern case, aod off
it the woollen bag is readily stripped by the workman's hands. The oil obtained b^
this process is the purest and most limpid ; but another process has to be perforsMd
before the seed yields all that the pressure is capable of extracting from it Tbe
cakes, therefore, when taken out of the bags, are broken up and put into the mortar,
where the same pounding operation takes place. When again brought into a eon-
minuted state, the powder is put into a circular iron pan or kettle, under which is a
fire, and slowly roasted in it, being kept from burning by means of an iron srmvhicii
is moved round inside by the machinery, constantly turning the ground seed. ^^^^
sufficiently warmed bv this operation, during which it is made to part more Mj
with the oil, the mass is again fiilled in bags and pressed as before, after which they
are finally, the bags being stripped off, pared at the edges, put in a rack to dry, and
stored for sale. The oil thus obtuned is darker in colour than that bj the cold
process, and contains more mucilaginous matter. Many foreign oil-miliers, howerer,
only employ the hot plan, believing that they have thus a larger yield than when the
cold pressure is first used. See Linseed Oii»
In England, the cold pressure is little, if at all, practised, the seed being ahnost m-
wariably warmed before pressure. The system of crushing, formerly nnivernlhere,
had some resemblance to the Flemish method above detailed, the chief differoice
being in the mode of preparing the seed, prior to its being put in the presa. Tbe
first process is to pass slowly from a hopper, the whole se^ into a pair of amooth
or fluted metal rollers, which, in turning on each other, crack the seeds. Btsrj
€dged stones then grind them into a meal, a little water being added during the open^
tion, which &cilitates the comminution of ihe seed. The meal is then pot in uc
kettle before described, and while heated and stirred in it, the water mixed vith
it is evaporated. It is then ba|pg;ed and put in the press, wher« the etampen, U^
on the wedges, effect the desired results. The most recent improvement u tbe mode
of pressure, and one now largely adopted, is the hydraulic press, and it is generaDy
considered that a larger yield of oil can be obtained by its use than by tbe wedge and
stamper-beam method. Blundell*s (of Hull) patent is that most generally employ^
and Messrs. Samuelson of that place are distinguished as makers of it, having Intro
duced themselves some modifications and improvements. The oil obtained from w*
seeds or linseed, as it is generally termed, is of wery extensive use in the arta, and s
the chieC vehicle for paints. To suit it for this purpose, and to make it diy qucUyi
it is mostly boiled in an iron pan, and during the operation a quantity of litharge »
dissolved m it The cake is a very favourite article with stock-feeders, being coJB*
bined, as containing much nutriment in small bulk, with roots or other vege^t»e
food, having large bulk with small nutriment. So extensiwely is it ^o^^^^v,.!"
Great Britain, that besides the yery large quantity made from imported seed, W
80,000 tons of foreign cake are annually miported. On the continent inferior qsvi^
of cake are ground to a coarse power, and either applied to the soil tf * ^^
dressing, or steeped in a liquid manure, and the mass spread out on the Und''
that state.
Scutched flax fibre appears in the market made np in different ways. B<^J!
in large bales or bundles ; Duteh and Flemish in bales weighing 2 cwt, the fibre btfi^
tied in ** heads," each of which is about as much as the hand will grasp. ^
made up in bundles termed *' stones,** the weight of which is either 16^ lbs. or S^| '^
In this state it is piled in the stores of the spinner, care being taken that it be p^
OB ftgrooDd-loor, fl«««dortiM,miidiM>t iDalKMrdcdlaft,u(lwhuiudUmc»pbn*
of the formtr ii coodiiciTe to Ihe prcMmtioD of the luppIcneM Mid *" jpuming
qinlitj ' <if the flbn, vkenw it detenortlM coniidMmbl; vhcn cxpoKd to ■ drier
The fint opendon irhieh it nndergoe* in the ipinnini; &ctorj m kacUiiig.
Thii piOMW it rtqmred to comb ud itraightcD the fibre*, to g«t rid of u? knot*,
and to lenen and eqnaliM the liie of the filamenta. The aetion of the baoklH oeoei-
asriiy diridei the Kntobed flax iolo t«o portioru, the loDg, Mraight onea, vhich r«-
msia after the flax hai paned thnxigfa the c^wration, beiag termed " lizM," and the
TooUy or eottOBj laakiiiK ma«a which remaini, being dMi^tad " tov." Both of
tfaeae are apan, bat the line prodDoe* tbe finer and better qnalitio of 7arn, and is con-
■eqaeadj mnch Bore Taloable than the tow. The great ot^ect, therefore, ii to obtain
the lwRMt[iaMibleiin»ntitj of tbe former fnnn agiren wetghtof (calcbed flax, and
Ihejieldof lineivtMeanMderablyaceOTdinf tothenatDreofthsMaKm. Spinnen,
therefore, are anxioM m e«oh new cn^ of flu ii brought to a marketable elate, to
text the peld of line, lo ai to gtude than in tbeir porchaiea, Ther are ihni enaUed
to aecertain more clearl; tbe loitalnlit; of tlte lamplee for •* warp " or " weft " j*rtu,
and far thre*d-twi«ting. Warp-jami being thoae vhich conatitnle the long thread*
of a linen &taric, reqaire to be harder and Itrongcr than vcft-jams, which form the
craaa or ihort tfareada.
The jrield of line, ai well ai the general ecoaom; of the operation, ii, of eoonc,
greatly dependent on the nature of the haeklin^-machine employed, and great eeope for
care and ingeoiiitj ii tbu ^len lo the roachme maker*. A great number of hack-
liog-macfaine* have, &om tone to tiiDc, been brought oat, employed in the fitclorica,
and mbaeqiient]; abandAied, when others, .luTing greater nerit, h«Te been in-
In the t*zij period of tlie linen nunnfbetnre, when ipinning wai done exclnuTel;
b^ hand, no hiwUin^marehine* were employed. The proeea wai exeltuifelj effected
l^ hand-hackle*. Etta after the introdnetion of niaehiQe-ipianing, the; were, for a
Im^; period, the aole mean* of hackling. Of late jear*, the machme hai been more
and mace brooght into nae^ and although hand-hackling itill exlMi to a ooniiderable
extent, the Mher method ia bj Ihr the more extenaifelj emplojed.
Fa- hand-haekling, the toola owd conaiM of a nrface nodded more or let* thicklj
with metal pcdnla, called hackle-teeth, through which teeth the flax ii drawn by the
llie hacklea <Hdinarilf a*ed for hand-hackling in thi* country are in the form of
ractni^olar p«rallelogrami,preaentingaliaeof 7 inehel toward* Ihe worker, and 4 lo
6 inche* deepi The fir«t tool eni|^;ed i* called the ■■ ruffer," the pin* of which are
about i inch aqnan at their baae, and 7 incbe* long, and brought to a fine point ; the
•e«ODd t* the^commoQ 8," which ii alwttri McdaAei Ihe "niffer )" then Ihe "fine
8,' tbe "10," Ihe "11," the "IS." Thepiuofall tbceetoolt areNmilarlj plaoedio
Aoae of the mffer, but are nmewh«t *h<Mler in length, and are more (lender u tbe
tMda iDcnMe ia finenew. lo all tbete tools the pini are held in wooden stock* of
about) inch in thiekne** and corered with ibeet tm. Thi* theet tin, through which
the pin* tre driren, help* to mpport then uid prevent the wood from i^ttinK.
Heae tin corered *toek* are only of a *iM neceeaary for the extent of pint on-
ploycd, and are them- —
■ehes KMewed to other
larger piece* of traard, a
little broader and aome
inche* longer thanthem-
■eWe*, and by which they
Ac hackler** bench, in-
It.
Fig. 808, end tIbw of
a hackle ; Jig. 607, front
view cf hackle ;.fl;. 80e,
hackte, &C., fixed np for
■wtyrkiog. a pin* ; b tin eoTered «toek ; e fonndation board ;
bench; * back boftrd; /table to receive the low, &&; <l hand of
240 FLAX,
tlie fonn of hackle used in England, and also the manner ihey are, of wbatera d^
acription, fixed for work.
The operation of manual hackling is simple in principle, although it reqaiRi nrndi
experience to acquire dexterity.
The workman haying first divided the flax into handfnls or strides, of which thm
are 800 to 400 to the cwt, proceeds to grasp one as flatly spread as ponibie betwea
his forefinger and thumh, by about its middle, and wind the top end nnmd his hnd m
order the better to prevent the slipping of the fibres ; he then begins by s drealir
swing of his arm to Ush the root end into the hackle, taking care to eomnKoee u
near the extremity as possible, now and then collecting the fibres by hokiiog kii kft
hand in front of the tool, turning the strick from time to time. He thus grsdoally vwii
up as near as possible to his right hand, when he seixes the mfied part of tb« tfrkk
and holds it in the same manner as at first, and proceeds by a similar trestoieat to
'* ruff" the top end ; when this is finished the ** ruffed " work is taken to the tool
called a ** common 8," the pins of which are much closer placed ihan those of the
ruffer, and are only four or five inches long. This ** 8 " is dways used after the
ruffer, but from it the work can be taken to any of the finer tools, vis. 8, 10, IS, lad
sometimes 18. It is usual and better to dress both ends over each tool before taking
the work to the next The pins of all these tools are 4- inches long, in order, ai wa
supposed, to have sufficient spring. The flue is not lashed into them si ioto tke
mfiers, neither are the ends required to be wound round the hand. Bat the root lod
of the flax is always the one to be first worked, and the hackling began st nearly the
extremity of the stick, which on being drawn trough the hackle is receired l^ the
left hand of the workman, and by it carried back and laid upon the bock board ud
over the point of the pins, for the angle of inclination of the luu^ea and a slight
lowering of the right hand causes it to enter sufficiently on being drawn forwarl Ai
it is impossible to mff or dress entirely up to the hand, when £e hohl is changed is
either operation, there must of necessity be left a certain space to be rqMMcd throogh
the tools ; this is called the ** shift," but the less length that is required for this {nt
pose the better for the yield of line. The numerous long fibres that slip fim the
strick in ruffing jnost be collected and drawn from the mass of tow attached to then,
when they can be relaid in the strick, or kept to be dressed separately nnder the
name of ^ shorts," and from time to time the short fibres or tow sticking to the teeth
of the finer tools are removed. Whenever one-half of the length of the itiake of
flax is hackled, it is turned round to hackle the other half. This process repeiiail
upon each hackle. From 100 pounds of well-cleaned flax, about 45 or 50 pooads
of hackled line may be obtained by the hand labour of 12 hours; the rest being
to jr, with a small waste in woody particles of dust The process is eontinoed, till by
careful handling little more tow is formed.
To aid the hackle in splitting the filaments, three methods have been had recoone
to; beating, brushing, and boiling with soap-water, or an alkaline lye. ^^
Beating flax either after it is completely hackled, or between the first and seond
hackling, is practised in Bohemia and Silesia. Each hackled tress of flax is f^
in the middle, twisted once round, its ends being wound about with flaxen ^^"^"1
and this head, as it is called, is then beaten by a wooden mallet upon a ^^^Jjlr
repeatedly turned round till it has become hot It is next loosened out, and robbed
well between the hands. The brushing is no less a very proper operation for part-
ing the flax into fine filaments, softening and strengthening it without risk of teanag
the fibres. This process requires in tools, merely a st^ brush made of svioei
bristles, and a smooth board, 8 feet long and 1 foot broad, in which a wooden pa
is made fiast The end of the fiax is twisted two or three times round this pin »
hold it, and then brushed through ito whole length. Well hackled fisx aoffert do
loss in this operation ; unhackled, only a little tow; which is of no ^'^'^"'^'1^
the waste is thereby dbninished in the following process. A cylindrical ^'^^^^
by machinery might be employed here to advantage. These have been tried »
establishments for machine spinning, but not found advantageous. ^
The object of all hackling being to produce a good yield of line with ^^ ^ ^
quality, that is to say, free i^m broken, unsplit fibres, lumps, and knots ; the ^^^Jf^
attention necessary to do this, with the expense and uncertain result of the i^div»^
skill of workmen, urged maoufitctnrers to attempt the establishment of n^"*^
effecting the process. Therefore many contrivances were invented with this tiev,
but it was long doubted whether any of them made such good work, with ^^^^^^
as hand labour. In hackling by the hand it was supposed that the operator vov
feel at once the degree of resistance, and be able to accommodate the traction to n,
throw the flax more or less deeply among the teeth, according to circumstances,
draw it with suitable force and velocity. For a considerable period these ^^^^^^
rather prejudices, as they may now be called, seemed to be confirmed; for the eariK^
FLAX.
241
attempts to saperaede hand hackling, like those in many other nndertakings, thongh
partially fkvoorable, were, on the whole, rather discouraging. In attaining one pout
denred another was lost, for too much still depended on the care and attention, if not
on the aetnal skill, of the persons attending the machines.
It will be desirable, therefore, to give particulars respecting some of those which
have been from time to time inyented, although they are not now in nse, as a lesson for
pTCTenting the repetition of things already known, as well as to illustrate the steps sue-
eesshrely taken. The first machine invented, or, at least, published, was called the
** Peter,^ and was intended to illustrate, as clearly as possible, the morements of the
band backler. The flax was first dirided into small convenient portions or handfuls,
aboat 4 OS. each, called '^strioks," which, bdbre being taken to the machine, were
slightly straightened and dressed over the ordinary hand ** rougher." Each of these
vas then placed between a pair of short iron bars, called a** holder," one of which had
an indentation in the middle, and the other a oorrespondinf projection. Thus, when
tightened together by screws 4^ inches apart (such lengu being equal to a man's
gnspX the strick of nax was firmly held while exposed to the action of the hackles.
The holder was then suspended from movable levers over a truncated rectangular
cylinder, upon the angles of which were fixed, at a certain angle, hackles similar to
those used in the manual operation. The levers supporting ihe holders received from
a crank a short up and down motion, so timed in their oscillations as to strike the
holder nearly against the points of the pins at the time thev were passing under,
coming itau as nearly as possible to the effect of a man striking m and drawing through
the hackles, except that the flax remained nearly stationary, and the hackle was drawn
through it by the rotation of the cylinder, whereas in the hand process the hackle
was stationary, and the flax drawn through it by the operator. Each machine carried
two holders. The tow made and collected from the holders was seised and taken off
by boys stationed for that purpose, while another, at the ringing of a bell, took out
and changed the sides of like stricks to be presented to the action of the hackles, and
aabsequently withdrew them from the first machine to another similar but with finer
hackles, and thus continued until the root end — always the first operated on — ^was dressed
to the desired degree of fineness, when they would be taken to a table where another
net of boys, previously to removing the first holder, put on a second to the already
hackled part, leaving about 2^ to 3 inches to be re-hackled. This operation is termed
" shifting,'' and the space left, ** the shift;" it is thus performed and remains so called at
the present day, the only change being that in the holder now in use one screw is used
ftyr two stricks instead oif two screws for one strick.
Pig, 809 will more clearly show the construction of this machine. A, square trun-
cated cylinder carrying the hackles ; b, oscillating arm or lever for supporting the
holder ; c c c, framing; d, crank and shaft ; a, connecting rod from crank to oscillating
arm ; f v f r, hackles ; o o o o, back board ; h, holder. The first motion was given
by polleys on the shaft d, which revolved 4 Umesto 1 of the hackle cylinder, by the in-
tervention of suitable wheels. The worm and wheels for the bell motion were at-
tached in the usual manner to the shaft of the cylinder.
Bfnehines of this construction continued in rather limited use without any change or
competition till about the year 1825, when a patent was taken for a machine known
as the pendulum machine. The flax in the
holder being suspended and swung back-
wards and forwards while the hackle re-
mained fixed, the flax was thus hackled,
stroke for stroke, on each of its sidea The
boys, as in the last described, snatching off
the tow as it was formed, and at certain
times, that is at each rise of the pendulum,
for it had a rising and falling motion to imi-
tate the hand workers in commencing at the
extreme end of the flax, passing the holder
from one recess to another of the pendulous
table, 60 as to arrive at the progressively
finer tools when ranged along the machine ;
bat sometimes the different tools were fixed
upon the angles of a square cylinder that
presented a finer range, the whole length of
the machine, by turning up a new angle at _
each rise of the pendulum, when the labour I
of the boys was simply to put in the tow
and take out from it the flax. The a4Joining diagram (Jig, 810), without entering
You II. R
809
242.
FLAX.
810
on any details of a machine that was so little used, irill make the fhecrj of Ha
action quite clear
A, hackle bench sometimes re-
volviog so as to present differeat
degrees of hackles at its Tarioos
angles, sometimes stationary with
the gradations of hackles npoo its
length ; B B, pendulum arms;
c c, equal wheels working into
each other ; d d, crank arms ;
B, radial slide-bars to proserre
the holder table Teiticai ; a,
holder table ; f f f f, hackles;
o o, back boards ; 1 1, direetioa
in which the holders swing; theie
were the same wheels, Jcc, st
each end of the machine, and
the holder table h reached from
one to the other. The wheels,
cc, with all attached to than,
were made to rise and bver
upon the hackles, and the bsck-
boards o to rise when the hackJe
bench turned.
About the same time another
patent was taken out for a ma-
chine, where the holders wen
suspended above one end of a
trayelling sheet of hackles. This
machine also required hand labour to turn and transfer the stricks, though the tow
was caused to fall clear from the hackles by mechanical means. The following
sketch (yi^. 811) shows the principle upon which this machine works, and though
never much employed at the time of its appearance, has subsequently served as a
foundation for those that are now in the zenith of their prosperity.
AA{fig,SU), sheet of hackles; b, support for holders ; c o, carrier pulleys for the
sheet of hackles. Fig. 81 2, a larger view of the hackle bar a o, in order better to show
the faller D d d, in the staples or grooves e e, and^^. 818, at the end of the hackle-bar
o o ; F F, pins of the hackles, between the rows of which the faller d d d acta to posh
the tow off the pins. There is a clearing faller d to each hackle, which is kept to
the bottom of the hackles at that part of their course where they are in contact with
the flax, but at the turn f d fly beyond the points, as shown by the effect of the cen-
trifugal force.
All these machines, possessing great similarity of features in regard to the
personal attention required, never came into such general operation as to supersede
entirely hand-dressing, either from their own defects or pr^udiees against their
employment. About the year 1830, in consequence of the new mode of spin-
ning being carried on
with considerable eneigy*
it was found advantageoos
to cut the flax into S, 3, or
more lengths previously to
hackling, which rendered
it necessary to ha?o ma-
chines peculiarly adapted
for this new short descrip-
tion of materiaL This ma-
chinCf known as the ex-
centric or circular ma-
chine, deserves consider-
able attention for its own
inherent merits, and the
extensive utility it has
proved to be of in suggest-
ing the principal parts of
those by which it bss been
supplanted. In its ori-
ginal form it was made of a breadth suitable for only one strick, and consisted of a
811
vrk ^ whi '^-l->.
mj — gBjj — XM — EZ] — MSi — n
812
nCi
813
B
FLAX. 243
CjUoder 9 It diuuater, apoD the vhole drcnrnftiCDee irf irbieh tt Intemli oT S or 4
inchct were fixed tfae backlei. As each machine could ddI j cur; one deuriptioD of
backic, it waJ □eceasarj' to employ a leriei of thew machines, called a " elan," irhen
the flax nqnintd to be dreiifd oreraiuecMaioD of finer taoli,eaeh ncceeding machine
tarrring * finer tool than iti predeeeaior. The hacklei «ere cleared of to« bj ooming
in contact at one part of their rerolation «ith a bniih roller, irhich al>0 rerolTed io
coDtact with ■ ejlinder cOTered irith card clothing, the point* of the pine being in lach
a direction a« to clew the bnuh fhtra tow, and al lav itself to be in iti tarn cleared by
the oaciUationa of a comb, vheace by rollen the tow «u brought into a iliTer. In
order to preMrre the conlinnity in ibe aupply of tow, aod mainlain the regalarity of
the sliTCT produced by it, the bolden with the flax were preacnted to the hackle
ejliDdei in a mantier peculiar to tbit machine, and in endlen auccewioD by meana of
certain eircnlar carrien placed at each end of the hackle cylinder, but excentric thereto,
and at auch a diitaace apart aa each ihoald bear one end of the holder u it ex-
tended acroa the cylinder pnivllel to iU axis. Thai, the bolden introduced at tbat
part of the circumference of these carriers farthest from the hacklea were carried for-
ward, white the flax wai in operation, till they were brought almoat into contact with
tha pointa of the pina, when, by the iuterrenlion of a ilide, they were withdrawn from
the raachine, bat with one ride only of the flax dressed, and tbM but on one tool; tbere-
toiv the holder reqaired replaJcing in the same machine, in order that the second side
of the Mrick ahoold be dressed as waa the first The holdera then required to be
carried by hand to each socoeeding machine of the class.
The preceding figure (814) shows the teadicB featares of these machines : a a,
hackle cylinder i b b, excentric wheel to carry holders in its recesaea h, h, h, fi./i; c,
■I de upon which the holders were laid so u to fall into the recease* A A of wheel
b; d, aljde for t^ing out holders ; e, brush cylinders with bnuhei i o, cylinder covered
with card clothing t a, holder come out; i, doffing comb. The apace of Ihe bolder
carrying wheel waa filled with bolden, and so maintained iu endless sncceaaion, and
thus each served iu aome measare to keep the end of ils preceding one down into the
ba«Ue*.
About 188S, a mftchme was patented consisting of two parallel cylinder*, orer which
the flax waa carried, reTolving in its progress so as to present the alternate aides ol
the strick to the hacklea, the progressirely finer tools being ranged along these
cjlinden, so that having paased the length of one cylinder one end was complelelj
finished. When the bolder was taken out, " ahiAed," and replaced, it was carried
Ijack along the second cylinder, and thus returned to where it commenced, finished.
This ntBohine, however, never was carried further than the expeiimentsl one for the
Mother machine (Wordsworth's) the same yetr made its appearance, and which
for some time enjoyed much celebrity. It consisted of two parallel vertical sheets
of hackles mnning together, and m geared that the hackles of one iulersected the
interstices of the other. The fiax suspended in ils holder ftora a species of troa^h
passed between (hese two sheets, and was thus hackled simultaneous!)' on each side m
FLAX.
w throngh the prdgnMivcly fioer hscUet from one end of tlie nuchine to Ibt
115), hackle iheeti ; h b, holder trough or slide) c c c c, pallej'l for arr;m|
lfa« hackle BheeU ; s d, bnuh rollen ; E i, roUen covered Tilh card elolhiiig to dw
(he bnuhci ; r r. dofler combs ;oaoa, hacklra ; a, holder; ii, bnuhei.
It is anneceuarf to notice more at length the dlBerent machiael broaght not, tm-
ployed for a timci and then rejected. Although the hackling and apiontng of Buin
the full length at it grows, was what was Gist practieed by hand, the fint rcillj nc-
ceasful macbine for hackling wu what wu known aa the " circnlsr nuidua(''far
hackling " cut line ," as it is called, or the long flax fiblv brahen Into sererll ieafik.
Il had always been known that the top and root ends of the fibre Were of Tery iii<'-
rior qu&lily to the middle, and of contse when all was span in oae length tht jm
produced was inferior to what the middles could be spun to, while nipeiiar to vbil
the tops and roots would produce. It therefore occurred that ia the general qmUlio
of flax the diyision of the fibre, lo aa to separate the different portioiu named, wotld
be advantageouB to the spinner. The operation of cutting was performed by a niop''
machine consisting of a pair of Jaws, so constructed tbM when the flax il intradimd
betwecD them the dilTerent parts, instead of being clearly cut off, are, to to ipoL
bitten off, leaving ragged ends. This is desirable in order that the ragged ends iiii|^<
interlace in the spreading prior to going through Ihe prepariog machines, whieli [■**
cede the spinning operation. The machine for hackling cnt line «h broagbl ™<
about thirty years since, and underwent, before it was flnslly set atide, a coasidenUe
number of modifications fbr the purpose of economising the laboai' in working it
About the same time the " flat machine " was introduced, which wm more partioilirir
intended for hackling long flax. The nature of the operation of tiiese machiDCi ■><
the same, the fiai being acted on by different aeries of hackles fixed in Ihe circnD'
ference of a cylinder in the one machine, and on so endless sheet in the other. Tk
curvature of Uie cylinder was no objection in hackliDgcutflai, but fttf acting on Iml
fibres it was necessary to put the hackles on » sheet, for the purpose of getting laS-
eient length of flat auHBce. The most successful mafbines, and wbi^ di^lawl
all previous ones, have been modifications of these of different kinds, some rf diM
being simply contrivances for saving manual labonr. and giving certainty to tbeactiooi
and others combining other improvements with this olyeet. Carmichaers paUnl w^
chine C/9i.St6, 817) was. as brought ont at first, simply the old flat machine wilh x"'
246 FLAX.
act'iDg motioni fbr aetnillng the holden applied to it. It was aftemrda mneli im-
proT«l b; the aduption of an iDcliaed sheet in imitatioD of ■ very laccesafal aelf-aet-
ting modificatioa of the old flat machine which wai brought ont bj Combe, of Bel-
foat. Those machine, at thi* time, it coniidered b; many to bs the beat one in me
for long line.
The diitiaguUhing fcstare Id thew rivnl machinei ii, that in Cannichael'i the
motiona ore all performed by the deaoeat of ponderoni weights, while in the other
they are performed by the direct action of the machine.
There are other differenoei affecting the working of the machinei, which an by
practical hacklers conaidered of great importanee, and aigiTingmureTaloe to Combed
machiiie. The moit important nf these ia the beililj of adjiutiDg the pla«e where
the holders approach the floi, which greatly affects the yield of line.
The same principlea of octaating (be holders were applied to cyliader machine* fiir
hackling cut flax, bat as these have been displaced by more recent inventioiis, it is
not necessary further 10 refer to them. Wordsworth's macbioe, already fi^<ii^(Sli),
was of importance, as btingthe basis of several olht^r valuable machines. Its essentisi
feature was arranging the hackles on two seta of endless sheets placed opposite each
other, and driven and connected by wheel-work so as to revolve together, the snrfsoet
being placed so close together, that the hackle pina penetrated &e flax from both
sides, and hackled at the same time. The Urge cirele de«er!bed by the pcants of the
hackles in this machine, which prevented them cutting the flax close to the holden,
•nd other ImperfectioDS, led to its abandonment About sixteen yean since. Combe
FLAX. 247
of Belfast, designed for the eminent flax-spinnixig film of Bianball and Ca, of lieeds,
a modification of this machine, irhich since has been known as Ardill and Pickard*8
machine, and has come into extensive use. The principal new feature in this machine
-was the introduction of cranked wheels for supporting and carryiug the hackles, for
the purpose of making the points of the hackles describe a small circle, and thus enable
them to cut close to the holders. Although successful, this invention did not fully
accomplish the object aimed at About the same time, Marsden*s intersecting
machine was brought forward, and possessed a great reputation for a length of time.
Its success was a good deal owing to the flax hackled by it having an apparent fine-
ness, but this was not found to be of practical value, as the spinning quality was not
improved thereby. For this reason it has gone greatly out of use.
The next machine which came into extensive use was Combe's reversing cylinders,
fi^ 818. These machines are constructed in a great variety of forms for different kinds
of work, and seem to give very good results. They are simple in their constrnctioo,
and give little trouble, acting lightly on the flax and making very wiry fibres. They
are made of all sizes, from 12 to 30 inches in diameter, and with 4, 6, or 8 gradu-
ations of hackles, according to the kind of work to be done on them. The flax is
hackled on each side, or each graduation of hackles, by reversing the direction of the
rotation of cylinders. The tow, or short fibre, is thrown off the hackles by stripper
rods, placed between the rows of pins.
The next machine to be namc^ is by the same inventor, and is styled the patent
reversing sheet hackling machine. It is for long line, on the same principle as that
jusi described, except that it has the hackles fixed on flat sheets, as in the **■ old flat"
machine. It is simple and complete ; easily driven and attended, and a considerable
number are now in use. From the hackles being on a flat sheet, it is necessary to
make the holders descend, first on one side while the sheets are moving in one direc*
tion, and then on the other while they are moving the other way. This is done by
supporting the channels which carry the holders on four levers fixed on two oscillating
shahs, to which motion is communicated by a shaft The holders arc slid through by
a lever on the top, which acts on a sliding bar, by means of a ball, which forms a
nniversal joint and actuates the holders, whatever position the channels are in. The
drawing here given, ^i^. 819, will show the mechanism.
Both the machines last described are made double, or in fact, the construction of
each is that of two machines in one. The table for filling and changing the flax in
the holders is attached to the machine. One side hackles one end of the flax, and
the other side the other end.
We now have to describe a machine for hackling cut line, patented by Mr. Lowry,
of Manchester, and now extensively in use at home and on the continent It is
Tirtually a modification of Wordsworth's machine, already described.
Fitf. 820 is a side elevation of a sheet hackling machine to which these improve-
ments are applied ; jig. 821 is an end elevation of the same ; fig. 822 is a front view ;
and^. 823 an end view of one of l/owry's improved hackle bars. In figa, 820 and 82 1,
a a represent the belts, sheets, or chains to which the hackle bars % are attached.
These belts, sheets, or chains pass around the small drums c c, and larger drums
d d, which are turned round by the gearing, shown in the drawing, or by any other
suitable arrangement of gearing. The hackle bars b, are made with a recess to
receive the stock of the hackles e.
The hackle bars b are connected to the belts, sheets, or chains a, a, by means of
rivets or screws, passing through the flanges b, and through the belts, sheets, or
chains a ; and at each end of each hackle bar is a stud or guide pin 6^, which, when
the hackles arrive near the small drums c, c, take into the groove in the guide plates.
The object of these guide plates is to support the hackle bars in passing over the
small rollers c, and during the operation of striking into the strick of flax or other
fibrous materizd to be operated upon. The holders with the stricks depending from
them, are placed within the rails t, t, and these rails are made to rise and ftdl and the
holders are made to pass flrom one end of the machine to the other, in the usual
manner. When the machine is at work the drams c and d revolve in the direction
of the arrows in^^. 821, and the hackle bars being attached to the belts, sheets or
chains a, and supported by the g^ide plates, cause the hackles to enter the stricks of
fibrous material at or nearly at right angles to the fibres thereof, and to retain that
position at the commencement of their downward motion ; whereby as the belts,
sheets, or chains continue to descend, the hackles are drawn through the fibrous
material for the purpose of removing the short fibres and extraneous matter. Another
great advantage resulting from this improved mode of attaching the hackle bars b to
Uie belts, sheets, or chains a, is, that the hackles can be made to enter the fibrous
material at a point closer to the holder than in any of the sheet machines now in use.
When the hackles are passing round the drums d d, they are cleansed by the
r4
248
FLAX.
revoWing brusbes i*^'» whieb deposit tbe material removed from the hacUei on to
tbe card drums k, k, Tbese drams are cleansed or doffed by the combs /A or in any
other conyenient manner.
Ok
00
This machine is also nsed to a very large extent, and well liked for dressmg half
line and full length flax. For this purpose the sheeU require to be made six inches
Umgtt frtm ceotre to ««ntK, and tb« head or trough to lift 3 inehe* higher, mi the
top roller* to appnMch and recede from each other dmnltuieoiulr with the Hung
nnd ftUing of the head.
Combe.of BelAut,hurKcntlf prodocrd another edition of Wordnrorth') machine,
Ita DOTcl feature coBiist* in diipeDiiDg with ban altogether, in carrying the hacklrt
and in lliiiig them directW on [he leather iheeti. By Ihii mean* a very tme action
it obtained, and the working parti are so light, that the nuwhine bean any (iteed
with icarcely any wear and tear. In thia invention there is alio combined convenient
mode* of regnlating the lift and Kverity of the cntten to anit different kindi of Sax,
and the holdera are carried through the machine by a lepaTate apparatoi for that
pnrpoee, while Ihey are at their highest eleTalion, instead of dnring the whole iiroceaa
of litliDg, at had uways been the caie in other machinei.
The entting of flax already referred to, ii effected by a machine consistfng of _a
apeciet of circular raw about 90 in. in diameter ', but, initead of a lingle blade, it ia
conatrueled of 3 or 4 platei of Meel, each about j in. thick, and having angular pre-
JectiDni from their circnmference. Thii revolvei at a coDiiderable velocity, while.
the flaa, flnnly graaped in each hand bj ita end*, i* still farther held and alowl;
250 FLAX.
Miried againit (he iaw bjr tiro p«ir of groored pnlle jb presKd togelher by a coander-
«ble weight. It U that partly sawn aud partly broken through. Flai may be cut
inlo S, 3. and somelimea 4 diTisioas : and lomelimea the dtad harsh fibre* thai are
fluently found at each of its ends only are cot off and >ued ai tow ; hot morr
gEDerally the different portion! are hackled and used tor the pnrpoae* they are lorted
for.
Ducrgition of fax adtug aachine (fyt. 8S-1, 835). ± ±, trtmiag ; B, the groored
pulleys for holding and carrying tha flax ; o c, the driving pnlley ; b, iaw or caller;
E, T, wheels for gearing together the pair of holdiog pnlleye ; o, b, i, k, pjnioni and
wheels for producing ^e proper ri'lative speeds between the cutler and poUeyi; L,
weight, which by IcTers H snd N. causes the pressure of the holding putleya.
Frtpariag. — -By this term ii understood those prelimiuary operations through
which both line aod low must pass after the hackling and before the spiuning pro-
The mcchaDism and modes of proceeding for this purpose which consist of repealed
dravings, are similar for "long" line or "cut;" though the dimensioDS and Gnenessof
the machinery must be made suitable for their various lengths and qualities. But ia
the preparation of tow a peculiar additional operation is demanded, as a consequence
of the different state of the fibres of which the material is composed ; this operation,
termed " carding," has for object to bring the highly irregular and entangled mass
into a somewhat more homogeneous and uniform state, previously la its bein^ after-
wards drawn aud equalised in a manner similar to line.
In the preparation of line the first operation is called " spreading." or Srst drawing)
and the machine employed a "spreader:" those subsequently are the second and
third "drawings" (sometimes a fourth is used), and lastly the " roving." It is upon
the spreader Ihjit the separate stricka of line are first combined and drawn into long
uniform bands or ribbons, called " slivers," of determinate lengths. This is effected
by subdividing the ilricks into two or three portions, and then placing them con-
secutively, slightlif elongated, and overlaying each other about Jibs of their length
upon )uid in the direction of an endless creeping sheet or apron. The machines are
generally made with two of these creeping sheeu or aprons, and upon each sheet are
thus laid two distinct lines of stricks; each of which forms a thi^ unifonn body i^
line, and capable of being maintained to an indefinite length. These endless creeiung
sheets supply conlinnously another part of the machine, where the body of " line " is
drawn out to between 3D and GD times it* original length, according to whether it ia
compoaed of cut or long flax. This part of the machine comprises a pair of holding
or back rollers ; an endless succession of bars called fatlers, bearing cambs of closely
ranged steel pins, thruugh which the slivers are drawn; a pair of iCawing rollers; an
arrangement of diagoual or doubling bars; and a pair of delivering rollen. Is
generally termed the " gill frame," or " gill head," probably from the French word
" aiguilles " (needles), as descriptive of Ihe combs, and to distinguish this macfaiiw from
tlioK ftmnerlj med ftr tbe tune pnrpow, which limplj conilited of b teriei of
tnllen, under «nd orer -which the line vu puMd.
Tbe rolldiriiig fignrea, 826, 897, ihow the ODtUne of the pment mo« ippTOTed gill
■prender or fint dnwiiig.
j> nidetnd ilightlj condenie the four bodice aTjliienof line! r, can (br
TceeiTinc the lliTcr; u, lever fur veigbt on front or drawing roller t B, lever for
- '-'^tonb«ckrolleriK,deti«-'— -*^^---'-"' — ' ^ .^.S _^.
n of ((caring between it u
length of iliTCT is deliTered.
a a, the iron drswiag roUer or bou ; b hb, the wooden or preuing roUer, bj the
pnesnre of which upon a a the ilirer ii held during the greater Telocity of Iheee roller*
OTCT that of c ; the holding or back roller* elonjpte in exact proportion of it* aog-
'meDtationj the holding roller e is in liko mumer preued agminit ■aotlin' a erinia
aniit the " gilli " in retainiDg the fibrta ; k A, hooked rodj to conneet the Ktigdud
leter A with the boldiog roller c, and bjr the pressure thus caused insoie il> dba :
hmm
mmmmi
wwr-M lii
d the sheet or snrftce of " gilts " com
$31 ; «, nibber or cleaner of presuog re
the slirer at the momeiit of drawing ; g, plait
turned in a rectangular direction and gnided to the delivering rollers *»!*'''• ^"^
tionof the sliver is more digtinclly seen at jSj. 833 j i, hanger or coanertor tpf pr^wj
roller 4 to its weight lever c; i t the screws or worm shaft fiir carrying '''* K™ Jr
dd; KM, the shaft with bevel wheels bj which the (crews al opposite side* ""T
frame are caused to move simultaneously ; m a, pinions for connecting the uppw "^i
lower spirals of each pair; oo, the caniB ot eicentrics for lowering and mung*"^
ban i p p, weighted guide lever or bell cranks for guiding the ftller in its desceo'. »•
tnoderating the shock caused by its weight when coming in contact with ** '""L
tlide or support ; g and r, wonn and wheel for bell motion ; ., t, •, p, ". »■ J'" "
wheels from pnllej to fW>nt roller and frma front roUer to back ; I, 3, S. li« " *r^
ing from back roller to sheet ; 4, 5. 6. 7, line of gearing from roller to deL«noi
roller ; 8, from roller to brush ; y y, from back shaft to back roller. . .•.
The machines for the second, third, and fourth drawings, ihongh in pi^^T
essentially the same, yet differ in some of their minor deUili from the foregowe' •*
FLAX.
233
tbey do Dol require the feeding tbeet to lapplj (heai, the " iUtct,'' from the ipreader
bsTiup lafficieat coherence u ID allow iuelf to be drawn from the coui direct b; the
back rollers of theae macbines; neither ii a bell motion requliite to determine the
lei^th of iliTert prodnced by them. The iol^olned aketchet (bow the geDeral pant
reqoiute ifis*. 83!. B33).
i. A (Jig*. S3S, 833), fVaming ; B, driving pallej ; c, support of tliTer carrier ; o,
roller for carrying iliier ; e, eondactori \ r. cao containing the ilivers tVom the flnt
drawing ; o, receif iug can ; B H, the hacUe carrying ipirali ; I, the diif ontJ or
doahlii^ ban i X, deliTering rollers ; i, the drawing rollers ) m, a, n, the retaining
6S3
The nmng ftwne it the same in regard to the arrangenieDt of its back and IVont
rollers and gJUa, aa the drawing fHmrs ; and as the poalaoi] and maaner of regolatiag
the poles are generallj the same M adopted for cotton, tht description of these parts
therefore doe* not require to be repealed ; bat an improvement patented a few yean
•Ince by Sir P. Fairbairn, of Leeds, of that part of these frames which relates to
254 FLAX.
regulating tbe taliiiig np moTemeiit of the bobbin meriu pulieDlar aMmtion, u bj h
the incoafeniencM of the older m«lliod of a weighted belt and cone, and those ttt the
more recent disc ttsmel, are entirely oTercome. The principle of thii improremnit
COnsisU of driring a pulley by pressure between two dlica raDDing at eqnal speedi in
oppoute directions, m seen aXfigi. S34. 835, 836.
Figi. S34, 83S. To obtain the TariiUe ipeed, initead of nsinfc a cone and belt u m
tome framea, or the poUey
and single disc as in otbot,
a b, the horiionta] driTing
diics,tbe lower one a is keyed
to the shaft d, while the opper
b is fVee to tun upon it; i^
bevel wheel fitted to or fonn-
iog one piece with the npp»
disc b ; c beTel wheel keyed
lo shaft d; e iotemiediste
beiel wheel gearing in the
bevel wheels c and t, so as to
torn them in npponte direc>
tions, and conseqsentlj the
discs to which they are di-
rectly or indirectly attached ;
g, the variable pulley covered
with leather and rating npon
the lower disc a, and imelf
pressed apon by the wdght
of disc A ) it is Ihu drivtn at
speeds varying according to
its approach to or ftvm the
shaft d, thn« answering the
pnrpote of the tiavernog
leather belt of the cone move-
' ment; k, shaft keyed in the
poUey g, tram which the variable motion is transferred to the bohbina.
Aserieaof preparing machmes, termed «"Bystera," consists in general (rfl spreading
of 4 divers at the drawing rollers, tmitcd into one by the donbling ban at the delivering
roUer, S frames of second drawing, in aU S4 bossea 2 ftames, third drawing mntaining
83ft 83S
FLAX. 255
ttqretfaer 36 boraea; if a fonrth draTing ii required, 9 framM of 34 liouet each, or
48 bosse* in bU. 180 ip'mdleaof TOTiag in 3 fVkniei will well anpptf SOOO ipiDdlei of
medium ipinning;. Tbe mode of luiag Ihii " i^slem " la, ■■ hu alrendj been said,
flm to spread ihe itricki of line opOD the feeding-iheet of Ibe "spreader," then to
receive the sliver or sliTert tbere produced into cam capable of holding 1,000 to 1,300
yarda of sliferi. Tboae c«n« ipecially intended lo receive tbe iliven ftom Ihii
nuchiae, are all made to one regular weigbt ; tbna, wben filled, tbe veigbl of lin«
eachcontWDS ii correctl; *«certained. and by Ibe bell motioD the length it alsoknoirn.
Upon tbia basis ia fixmded ihe method of producing in; desired Dumber of 7am, and
by donbling the slivers, a degree of equatitntioD that the simple spreading would be
nnable to effect; for at each drawing, and at the roriog, aereral of tbe slivers fh>m Ibe
^ecedias dnwing are put logtcbcr, lo be again redautd to one for Ibis ot^ect alone.
Hence, t£e weight of n detenniDBte length in jardi of the desired yam being known,
a catcnlation is made, combined of tbe drafts and number of donblinga the material
has lo undergo, to determine what tbe weight should be of that length of ilivers con-
tained in the cans fh>m tbe spreader. It is ordinary to pul 10 or 15 of these "cans "
together, lo form wbat is called a " set," the slivers of tibieb are nniled at the second
drawing with tbe subsequent drawings and rovinga. The combination of two or three
■liven at each boss ia EuSiiieat.
Though Ihe above is descriptive of the " gill ' frames now in Bse, ;et it shonld be
imdenlood tbey are by no means the first or only results of the attempts made to
correct the defective principle of Ihe original roller machines, which were incapable
of holding or retaining the flax with a sufficient degree of regularity, owing to it*
Dnequal lengths and nnadbeaive nature. The consequences were that Ihe yama pro-
dnced were ** lumpy " and Dnlevel, making it evident that tome improved me^na were
oecewar; for more completely reatraining and regulating Ihe drawing of the fibres.
The mori obvious way to do thia waa to introduce aome mode of partial detention by
cresting a friction among the fibres to imitate Ihe nclion of Ibe fingers in band -spinning.
This led to causing the slivers to pass throngh and among several ranlu of serrated
pins, which was found very nearly to atlsin the object, and certainly greatly improved
the levelneu and Dniformitj of the slivers. Thus the use of " gills " became general
abont thirty years since.
Those firal brought into general use were conatrncted with circular disca or pUtet
for carrying tbe faller or gill bar, which at the same time were gnided by their ends
passing in fixed slides, so aa to bring the gill in a* renical a position and aa near the
drawing roller as possible.
The fignres (837, 838> are
profile and front views of the
working parts of one of these
gilts : — A, slotted plate or
disc, of which a pair were
keyed upon a shaft B, so as
to carry each end of the
falter D, passing through the
•lots c c; E, the fixed ec-
centric slide i a, b, the draw-
ing rollers ; r, the holding
This wat succeeded by the
"chain gill," in which tbe
fldler» were carried forward °"
by an endlesa seriea of con-
nected links, or jointed to-
other "Blotted plates," in-
■uad of the simple circular.
The object of thia was to in-
crease the flat surfiice of gill
baiB between the holding and
drawing rollers, making it
more suitable for the longer
dewiriptioni of malerial. The
slides and rallen, being simi-
lar in these machiires to thoM
in the former, are not repeated, but Ihe sketch of five slotted plates la given In
fiSf. 839.
Frem the evident impor'anca of bringing Ihe retaining effect* of the gills u closely
256
FLAX.
840
o s
CZG:;^LijL-J..:>v:^::n-:jz=j=^ \)
d]
as possible to the point irhere the moyemeDt of the dniring fibres is grealcMv
several attempts have been ro^e to improve the above described gills in this
respect With this view Messrs. Taylors and Wordsworth patented a gill o€
considerable ingenaitj C^.
839 840), which therefore de-
serves mention, though it
never came into use. Its de-
scription is as follows : —
a, b the falter or ** gill bai^
in one piece, which was
carried forward by an endless
chain ; c, d, slides placed hori-
zontally over the gill sheet
guiding the ends of certain
bell-cranks e, /, joined at
their angle in the recess/^ g^e,
of the ^1 bar, and at their
other end to the gill or oomb
a. By this arrangement, as
long as the bell cranks are
in the parallel parts of the
slides c, <f, the g^U teeth will
be above the faller a^ b^ bat
when they arrive at the con-
tracted part the guided ends
will be brought into the posi-
tion Q Q, and conseqoently
the ^ill depressed is o fi ;
this IS so timed as to cause
them to clear the drawing
roller, when, on again con-
tinuing their course, they
are again caused to rise
and penetrate the sliTer by
the reversed inclination ii
the slides c, <^ at the back
roller.
The objection to this in-
genious machine was the
largeness of the space sud-
denly left open by the de-
scent of the gill, as the double faller, bell crank, and gill necessarily occupied great
width.
The screw or spiral movement of the fallers, which was soon afterwards invented,
quickly supersede all others in use, as by these means the faller was caused, even in
the manner they were first constructed, to approach closer than even in the most per-
fected construcUon of the others, to the side of the drawing roller, and still maintain
the pins in a vertical position. Recently this object has been more perfectly at-
tained by a patented improved construction adopted by Messrs. P. Fairbslm and Co.,
whereby the obstacle to the fidler wholly touching the roller has been removed, and
thus producing the full holding effect of the gill to the latest possible moment This
is effected by employing a method of supporting the spirals by their working in
tubular recesses in the side plate of the machine ; idong these recesses are longitudinal
openings through which the faller end passes to enter between the threads of the
spiral, and which serve also as slides to support the faller. As by this means the
supports or plummer blocks that intervened between the end of the spirals and the
roller are suppressed, the faller is enabled to advance to the place they formerly ooen-^
pied. Figs, 841 and 842 show this comparison of the older and more recent methods.
A, B, spinUs ; c c, the parts by which they are supported, being in fig. 841 small
pivots in plummet block d p, and in^^. 842 hollow tube-like recesses in frame plate
c c ; B s, pinions to work the upper and lower spiral together ; f, bearings ; o, draw*
ing-rollers ; H, pressing rollers ; 1 1, passage of the feller*s descent
Here it may be as well to observe that me same parties have still more lately intro-
duced another important amelioration in these machines for remedying the noise and
wear and tear which ordinarily attend them by the abrupt and violent descent of the
faller. Fig. 843 shows a sectional firont view of a heiul having this improTcment
applied. A a, supports for screws ; 6, c, top and bottom screws ; d <( the new cams
FLAX.
257
1 i&ifti pwsHd with llie kkwi, and rerolTing at the Mine tpeed. Thai, these
d raccWe the fUler > * >t their IwBest diameter, at the moment they are tten
tbA, and guide them gradually dovn to the loireT slide.
I coDttnicted, the " KTew gill ** continnea to be the moat eateemed in principle^
not without ioma aerioui objec^ua in practice, for the abrupt and angular
of the " bllet" erco here not only liberal«i too (uddeniy a portion irf tho
|Ht=C
fibrea that should be but graduaHy relaxed at the moment of being drawn, bnt cauaea
conaiderable wear and tear to itfeUI the slides, and the gilla attached to it ; to which
came of destruction mnil be added the great ftiction of the worm movement; tbese,
howerer, in ' line " preparing, where the Sbrei are long and straight, and the drafts
employed large, and where, coDseqnentlj, ■ comparatively slow moTement of Uie
^lU is teqnlred, are not so much fell aa in tlie preparation of tow, where they become
„ . .. _ , 0 respectively called the
" breaker and the " finisher " «Mila. They are essentially the same in piinciple, and
vary bat little in eonitmetion, the only difference being that the " breaker " ii fed or
tnpplied by the dltjoioled paroeU of tow tctnu a creepmg sheet (as the spreader with
** line"), and delivers its slivers into a can, whereas the flniiher is fed frsta a bobbin open
which several of the slivers from the " breaker " are onited by a. machine expressly for
itiac parpoae. called a "lap frame; ' thiseard thus receives its supply of work in a very
regular form, and previously to delivering it in the form of slivera causes them to pass
over ■ gill, to consolidate and strengthen them before delivering tbem into the receiving
can; it is also generally clothed with a finer description of wire filleting than the
breaker. Tbongh it is the tietter method to card thns the low twice, yet Uiis second
carding is sometuoei dispensed with ; in that case this auxiliary "gill " is similarly
fixed to the flril card or breaker. The cards employed far tow are muchines of con-
siderable weight and importance, the main cylinder, or, as it is lometimes called,
■'swift," being from 4 to S feet diameter and 4 to 8 feet long ; thoae most generally
employed are e feet long. Previously to entering upon the detailed description of a
' card. It may be aa well first to trace lo general terms (he ptogreis of iti operations, aa
lending to dneidate. the explanation of the machine itielC
258 FLAX.
The tow U fint divided by weigbing iato BmnU parcel* of I (y to 90 dmna ; (bim
are Ihen gluken oiil and spread to bi to cover certain definite poiiioBi of the cree{Hng
feeding sheet, b; vhich theyareconductedtotbe first pair of rollers, called Ihefeedert.
TheK rollers are covered with a leatbern band, in which are fixed in cloae mmj a
□umber of vire points aboal } an iach long, and hariaga tangential incIinatioQ to the
circumference of the rollers, vhich areabojl S^ inches diameter. The tow passing ala
slow rate of progrestioa between tbese rollers, is hj tbem graduall}' presented u> the
points with which the swift is likewise covered, aJao set in leather bands, bnt which are
about a inches vide ; these points, the Same length as those of the feeders, have an
inclined direction pointing to that in which the cylinder turns. The much greater
velocity of the "cylinder" combs and somewhat opens and breaks the tow ai It skiwljr
arrives in contact, and the inclination of the pins at the same time carries it forward.
All aach lumps and fibres as are not sufficiently opened aod strughtened by this first
contact, renuuoing prominent on the snrface of points on the cylinder, are carried by
it against another roller, whose axis is parallel, and whose wire-covered circumfereiKe
is brought as near as poiuible, without atnolute contact, in order to catch and retain tbese
promiuent Inmps and fibres', the points of this roller (called a" worker '')areiacliiwd
in a direction opposed to the movement of the swift, and, therefore, hold the "tow'lo
be a^Q combed and straightened as at first it was by the feeders : this is repealed eiriit
or nine times, by having that numberof workers to the card; each of theae workcn Ins
its attendant roller, also covered with wire points, by whose inclination in a oootraiy
direction, and by the greater velocity of the roller, the low is stripped firom the workers,
to be again laid onto the cylinder. The strippers, tbongh running at a greater vehtcity
than the workers, are still slower than (he cylinder. The tow thus carried forward
gradually improving in openness and regularity as it passes each pair of " workers asd
strippers," finally arrives at the roller called adoffcr, of which there are two or three
apoD a card, the wire points of which are in saeh a direction as to hook or catch the low
" as it flies." The use of these several doffers is. that by placing each succeeding one
progreasirely nearer the swift, the longer and shorter fibres are successively and sepa-
rately taken off, Each doffer is cleared by an oscillating comb, and the sliven con-
ducted, if intended for the lap machine, into a can by deliveringrollers i but if finished,
these delivering rollers are as it were the hack rollers of (he auxiliary gill, patented for
this application by Messrs. Fairbaim and Co. ; whereby the slivers are not only saved
JVom all danger of derangement in their loose and porous state as direct from a card,
bat the hitherto doable expense of carding and first drawing is reduced totbi»t<rf
carding alone.
4 rollers and workers driven by one belt Ihnn pnllej' ■, and
FLAX.
tiglU b7 the BOT*bl< poller > > oaa, vorkera i 1 1 1, tlie ttane dofltoi
intennnUaM wbeeli to connect tlu morement of tlw doffcn -with one wullicr
n— ill«ti¥ig oonili* for their mpective doffera ; i, deliverins rollen i m, baok
mmilimrj ^ ; n, p]l ini&ce ; o, p, drawing nHUn ; tt, deliTering TtiUen .
motkKi for measanng the (lirer in ^e ean* K t ■ ■■ doubling pltle ; T, pnllej 1
ing •nxiliarj gilli t^ bell from the poUej >.
1 K«K,
roller of
The Up frame, to which alloiion hai already been made aa the neeeeaar; ai^iiiict
to the eardi when doable carding ii to be perfbirned, ia emplofed to collect toother a
immber of ilivetE from the ** breaker " bj winding or lapping Ibem opon a cjludrical
pieee of wood, which roaj be described ai a bobbin sbsok, tbns prodnciug an eqna-
liaation of the iliTera of tow as the making up of leta effected in line prepanngi trota
50 to 80 Iba. of tow ii the ninal complement of one of these bobbina, the length and
the diameter, when fail, abont S3 inchea ; tbiu, a 6 feet wide flniiher card will take
off theoe bobbin! at once ; from IS to ao is the number of sliien naiiall; wound to-
gether, and the completion of a bobbin by the ringing of a bell, connected with the
meunrin^ cylinder of the machine. The following ii a descriptive drawing of the
A. A X (Jlgt. e4S, 847), framing; K, meataiing and pretiing cylinder; cor,
driving pnllejs connected mlb different gearing to change the ipwd ai the bobbiof
meuanng cylinder hj tlie eonnetttng roda a o o, irhich are iplit for part of their
lentil in order to pau the shnft b, and at another, g g, have racka into vhich woric
pinioni keyed on the shatl of the band wheel I, for the conTenlence of railing and
lowering the cylinder and weight. The abaft B is divided at (he plates k and l, and
proTided with aocketa to recelie the end of the bobbin shank d. which is iiitrodac«d
by sliding back the piece h n, and returning it by lever n, and thus is coopled and
tQTDB together with two piece* of shaft H, aa alao the disc plates K and l, which are
to serve ai temporary enda to the bobbin during the time of ita filling, and thoa b/
taming with It avoid that robbing and felling effect npon the edges of the tow so in-
jurious id the machines formerly conslnieted, and by the bobbin sctiog as the driver
to the cylinder the slivers arc drawn lighter, and thereby avoid those plaits that the
other machines were sb liable to produce.
Aa before mentioned, aome objections were foand (o the irorhing of the acrew-gili,
ofa nature detrimental to the machines themaelrea. which, though not of great im'
parlance in " line," were much aggravated in tow preparing, as the lesser drafts there
employed cause a greater wear and tear of the fallen and gilla. The obJectioD to
theae machinea, however, is not confined to (his point only, but extends alao to their
effect upon the material itself. The fibres of the tow aliver, as coming from the card,
are in a light and mnch confused state, which renders Ihem liable to be easily separ-
ated) so thai the &ller, by ita sudden descent, has a tendency to draw aome down,
aod become lapped bj them, aa well as to make io marked a diSerecce iti the thick-
nets of the aliver, by the withdrawal of the retaining comb, so as materially to iqjure
the qoality of the yam. Thus this " gill " vras not enabled to hold iti place in tow
■pinning, when other circumstancea led to greater attention being paid to thla im-
portant branch of the flax business, and it became a desideratum to have a machine
free from these defects, and capable of working without derangement, at maeh greater
velocity than was aafe with the *> acrew-gill. These desiderata the "rotary " gill,
patented by Messrs. Fairbaim and Co., amply auppliea. For in thia gill the circular
form of the gill sheet obviates the necessity of having several fallera, and the simple
motion creates neither friction nor abruptness of effect, while the retention of the fibre*
being continnoDi, the ilivers prodnced are perfectly level and uniform ; consequently
these gilla are extensively applied, as the Boxiliary gill explained in carding, as well
JM for tha Bobsequent drawings and rovings of tow, and sometimes, at will be alter-
FLAX.
261
irards seen, to ooane f pinning. The theoretical constraetion of theie lotarj gills irill
be seen by the annexed sketch.
M OS7. 848^ back rollen, bat when applied to a card a top and bottom holding
ToUen are again employed ; k, the rotary gill sheet hsTing the pins inclined back-
-wvdSy so as to ensure the impalement of the sliTer when the fibres begin to draw; p
848
yB|M ^J
and o, the drawing and presdng rollers ; the doubling bars or plates are the same to
these gills as to the *< screw-gills.**
A machine has been lately inTented« and brought out by Sir P. Fairbaim and Co.
of Leeds, called Heilmann's tow combing machine {fig. 849)» which, on trial, is
much approred of. The tow is first carded in the ordinary way, say on a breaker
card, and then on a finisher card ; the latter deliyers the tow in die Bhape of a
slirer into cans, which are next placed at ▲, or back of the tow combing machine.
849
From the cans A the tow goes to the back conductor b, diyided into as many com-
partments as there are sUvers ; and from the conductor b, to the feeding box c sus*
pended on shaft d, without being keyed to it. The front lip s of the feeding box is
S3
262 FLAX.
Anted and fltl«d vith IsKther, and • cormpondiag' nipper r bnug fVom the Mme duft
D, utd keyed opon it, completea the jaw which haa (o hold nit the tow, while the
eyliDdar a otmht ic
The feeding box o derivea it* motion fh>m ibe nlpptr V, whioh ia moved bf lem
■nd eieeUrio m ■hown, and followi that nipper by ita own weight, nntil att^iped bj
iodiarubber buffera h ; when tlie nipper r in going further back Jeavea it, and (he
jaw B V open* for more tow to be fed, and the tow already combed to be drawn throng
the detaining comb I, aa explained hereafter.
The top E of feeding box i« movable np and down, by meana of the cmuecting
rod I. hang on a fixed centre N, to IhM the lop part K opeos or ahuta ta the t>odj of
the box goea backwarda or fbrwordB. Tba leTcr* K N K are only nied to keep the top
and bottom of the box parallel to each other.
Ab Bhown in the drawing, the top of the tbeding box ia fitted with hacklea paating
throngh two grates o &nd f, feat on bottom of feeding box, and leaving between ibem
■ space tliniugh which the Oliver has to pasi.
By the above arrangement, the hacklea are canaed to withdraw from the tow, while
die whole box ia drawn backwards on slides of table Q, by (he eccentric motion n x n.
The laat backwards motion takes place while the jaw s is yet shut, and the top of th«
box np ; but when the latter has got closed again, then the whole box slides down oa
the table q to its fbrmer position, bringing with it the sliver of a quantity equal to that
move : this completea the feeding motion.
Ko» a« the feeding; box recedes, the lip n cornea nearer to the combing cylindeT t^
the hackles a a cleaning the tow prpjecting outside the nipper v. As soon as they are
passed throngb, the feeding box comes back to the most forward position, when the
nipper I leaves it, and the Jaw e r opens : at the same dme the two roUera t u haTo
reached their top poailion. The top one t is then thrown forwards {hj the lever
arrangement ahown in v -w) upon the leather vr, stretched on putt ofmirtmot at
cylinder o;thU roller t is thnsdriveo, and takes btjdt^ the p4unts^ the tow presented
to a by lips or bottom jaw m ; a flue detaining comb i bemg just before interpoaed
between them to keep back the noils, that have not been carried off by the <'<>"l>i"g
cylinder.
BSO
In that way the points of the tow are driven npoo the ahcet X| until the roller t,
by being thrown back again off the leather w, their motioa is stopped at the same
moment, the two rollers tr and t are allowed to drop down by eccentric ▼, drawing
with them (Ihnragh the detaining comb I, and qoite out of the rest of the diver) the
Mheread* of the nbres of whieh tbey have got hold.
While thii baa been going on, the feeding box has advanced the alirer a Map, the
.e loUen x tnd D com* Op ■gain. H>d daring tlisl npirtrdi modm
tbe Utter cndi of Ibe fibre* putly c<Hiibed and DTertanied by the cylinder iMoklei, h
thown m diawing, are combed by tbem in (h^r tnm. Then the rollet t ii once more
diiTen loond }>j Qte leither w atretehed on cylinder, the new poinu plice themtelTe*
•bore the back eodi of the fibrei combed before, and are (■rried fbrwardi into » oon-
tmnoui iIiTcr on the leftihcr iheet z, from (he leather ibeet to the rollera s s, then to
the trmnpet eondactor a, (he front deliver; roller c, and (when more than one bead
to the skacbioe) from c to the end deliTery e, over the conducting ^ate A
2&i FLAX.
^ ^fy 9t &nd K JEtre the tiBiial brush, doffer, comb» and tow box Tor the noih.
These comhing machines are made of different sizes to suit all sorts and lengths of
tow ; the yarn produced from them is much finer than that produced by the ordinary
carding system alone. The combed tow can generally be spun to as high nombers
as the line from which it has been combed, and in some instances has pnxtaced good
yam, e^en to higher numbers. The combed tow, after the combing machine, is
passed through a system of drawing, roring, and spinning, similar to that used for
cut line.
Subsequently to the carding the preparation of tow is completed by making np sets
of cans for the second drawing, as explained for line ; these slivers are doubled and
drawn once or twice more, and then roved. The drafts used in tow preparing are from
9 to 8, for, as the fibres are shorter, it necessitates the employment of less draft. In both
line and tow preparing, lesser drafts are employed as the stages advance, the gills finer,
and the conductors narrower: also for both materials much attention is requisite to
keep the various parts of the machines in good order, free £rom bent or broken pins*
and chipped or indented rollers, for no subsequent operation can cure the defects that
may be produced b^ negligence in these particulars. The drawing and roving fismes
for tow are shown mfigs. 850, 851, 852.
A A 0^.851), drawing frame; b, driving pulleys; c, rotary gill sheet; d, drawing
roller ; e, pressing ; F, o, pairs of delivering rollers; h, doubling plate ; x, back oon*
ductor ; k, back roller wheel with pulley to turn the sliver rail L.
A A 0^«. 851 & 852), roving ftrame; B, pulley and fly wheel combined ; c, drawing
roller ; d, rotary gill ; a a, stand for gill movement The regulation of the bobbins
is effected in the same manner as already described for line roving.
Spinning, — This operation consists in drawing the ** rovings " down to the last
degree of tenuity desired, and twisting them into hard cylindrical cords, which are
called " yarns."
There are three modes of performing this operation ; the first, and perhaps oldest,
is that where the drawing and twisting are performed altogether, with the material
preserved dry, and without breaking or shortening the fibre ; the second is that which
likewise, without changing the length of the fibres, draws them while dry,
but wets them just at the moment before twisting. This method is the nearest imi-
tation of hand spinning, and makes the yam more solid and wiry than the first ; as
the fibres of flax losing their elasticity while wet, unite and incorporate better with
one another. The third mode of spinning has been much more recehtiy introduced
than either of the others, and by it the fibres are wetted to saturation previously to
being drawn, whereby they are not on\j much reduced in length, but their degree of
fineness is increased by the partial solution of the gummy matter, inherent in the flaxen
material : owing to these circumstances equally good yams can be produced by this
mode of spinning ftom line and tow of inferior quality, to what could be employed
upon either of the others, and not only that, but much finer yams can be now spun
than were possible previous to its introduction. It has therefore not only nearly
superseded all other methods of spinning for yams from 20*s to the finest, but has
much increased the extent and importance of the flax manufacture.
The only difference in spinning ftumes for ** line or tow," when employed for the
older methods, consists in the length of reach, which generally involves the necessity
of having separate machines for each material, though sometimes they are made with
a capacity to be adapted to either purpose. In the third method the same machines
are used promiscuously for '* line or tow.**
The yams spun wholly dry are used for the coarse description of woven goods, as
packing canvas, com sacks, and, when partially bleached, for sheetings and towellings,
as from its greater elasticity and openness it fills np better in weaving. Those span
partially wetted are employed for a somewhat superior description of linen goods, and
the solid silky appearance qualifies them for drills, damasks, &c., as well as for sewing
and shoe threads ; a somewhat inferior material, by this manner of treatment, makes
an equally good yam as a better material spun dry. The yam produced fttnn this
wet principle is rather inclined to have a cottony appearance, and from the comparative
ease with which an inferior material can be made to present an apparentiy fine good
yam, the application of yams thus produced is exceedingly various and sometimes
deceptive, though when good materials are used, these yams afford durable and
handsome drills, shirtings, lawns, and cambrics, as well as fine sewing threads.
The mechanical arrangements for twisting, and then winding the yarn upon a bobbin,
is called the ** throstle ** principle, supposed to be so called from the whistling noise they
create when working at ftiU speed, which is ftom 2,500 to 4,000 revolutions a minute.
The following diagram will explain the principle, which is applied alike to all the
modes of spinning above described.
A A (Jig* 853), the spindle ; B, the bobbin, loose and independent of the spmdle in
FLAX.
265
regard to taming, and rising, and lowering, bat tfaroagh which the spindle passes;
cc,the flyer screwed to the spindle top; d, table called bobbin lifter, as while at
woriL it rises and lowers to lay the yam on the whole bobbin eqaally ; b, a small
cord to press on the bobbin by the weight r: o, policy by which the spindle is
driyen.
Many attempts have been made to improve apon this principle, in order to
avoid or lessen the strain apon the thread in its passage fVom the drawing rollers
to the flyer eye; bat, till recently, withoat any degree of saccess. The only improye-
ment at present known, and which promises to become general, is that where the
necessity to hare a top to the bobbin is avoided- It will be seen from the above
853
854
t
diagram (858), that the yam is compelled to rab the top of the bobbin, and the friction
thereby created qoickly caoses it to become rough; and therefore it has a tendency
to catch and break the thread. The desirableness, therefore, of having a clear
coarse for the yam was evident, and this improvement that we are about to ex-
plain produces the effect by employing what is called a coping motion, which, like
that used in molespinning, preserves the layers of thread upon the bobbin ever in a
pointed or conical state, and therefore self-supporting without the ud of the wooden
end of the bobbin. See Cotton Spimnino.
The arrangement of the rollers for holding and drawing the slivers or rovings, as
well as the plates and rollers for aiding to retain the twist of the rovings, in order to
render tiieir donsation more equable when to be drawn dry and spun upon the
older methods, wi& be seen mjig, 854.
A (^Jig, 854), roving bobbin ; B, back or holding roller ; o, carrying roller ; <f, flat plate
with a slightly curv^ &ce ; the carrying roller and plate are so placed as to cause a
degree of friction to tiie roving when passing over them, so as to retain the twist, and
thus act as the pins in the "gill friunes ;" e, tin conductor for contracting the roving
at the moment of being drawn; f, metal roller; g, wooden roller pressed against the
drawing roller in order to pinch the roving; A, lever and weight When it is in-
tended to wet the yam previously to twisting, the trough t is used, in which is water,
"which is supplied to &e roller g by the capillary attraction of a piece of cloth im»
inersed thioein, .and bearing against the roller by leyer fu. i
FLAX. 267
«Dd flcenrately fluted into one another. The water nied is heated, in order by the
ez[Ni]sion of the fixed air more rapidly and completely to saturate the roYings while
passing throngh it. The following drawings and description will be sufficient to give
an accurate idea of the principle of these machines, which are generally 20 to 30
feet in length, and contain 200 to nearly 300 spindles; that is, 100 to 160 on
each side.
A AAA {jSfft* 855 & 856), framing; b b, stand for roving bobbins ; c, driving poUeys
fixed npon the axle of cylinder d, ttam which pass endless cords to drive the spindles
ee; P, step-rail of spindles ; o, collar rail for ditto; H, bobbin lifter; i i, front roller;
K K, back roller; i., back pressing roller ; m, top pressing roller (these are generally
made of box wood, bat sometimes of gntta percha) ; n, v, levers in connection witn
the exoentrio to prodoee the rise and fidl of the bobbin lifter; o o, thread-plate ; q q,
saddles or transverse ban resting on the axles of the back and front pressing rollers,
so that one lever and weight acts for both b^ the connecting rod and lever r r, which,
in order to came more pressure on the drawmg than on the back roller, is placed on
the saddle nearer the former than the latter. 1, 2, 8, 4, 5, 6, 7, 8, train of wheelwork,
by which the movements are distributed, a a a, the trough of hot water maintained
by steam-pipes at the desired temperature; b b, guide rods or pipes to cause the roving
to pass onder the water. In order to aToid the rollers becoming indented by the
roving always passing on the same place, they are caused to trayerse the breadth of
the r^ers l^^ a traversing guide rail, moved by an excentric at the worm and wheel
c ; d, flyers, andy^ spindles.
Here it nmy be proper to introduce a descri^on of the machines for twisting the
yams when span into ** threads " used for sewug, ftc The yarns spun for this par-
pose should always be made of a somewhat superior description of line to that em-
ployed for the same mmber of yaios for weaving, and have rather less twist They
are generally taken while wet on the spinning bobbins to the twisting fram^ and,
when combined together, the union is effected by a torsion in the opposite direction to
the original twist of the separate yams.
Bedutg. — This operation consists in winding the yam off the bobbins of the
spinning or twisting frames, and forming it into hanks or skeins. The yarious deno-
minations of the skeins into which yam is reeled, and then the forms or combinations
they are made up into^ are as foUows : ^-
The lea containing 300 yards
10 leas making 1 hank
20 hanks „ 1 bundle
6 bundles „ 1 packet
It is by the standard lea of 300 yards that the description of yam is known from the
number contained in 1 lb. weight; thus. No. 20 contains 20 less or 6000 yards for
1 lb. weight In Scotland, the subdivisions are rather different ftom the foregoing,
which are employed in England and Ireland; the lea, however, remaining the
same: —
38 leas make 1 spindle
6 „ 1 rand
12 rands „ 1 dozen.
The reeling is performed npon exceedingly simple machines, generally put in mo-
tion by the hand of the person attending them, though sometimes they are driven by
the motive power of the fiictory. The reel is made sufficiently long to receive twenty
bobbins, and the barrel npon the yam is wound in one length; the diameter, however,
varies so as to suit the different sizes yarned to be reeled. For the coarsest yams and
down to 16 and 20, the lao'gest circumference is used of 3 yards, fh>m that to about
No. 100, 2^ yards, and for the finest yam 1^ yards is found most convenient These
▼arioos circumferences are compensated either by putting a great number of threads
into each ** tye," or increasing the number of tyes, so tiiat opposite to each one of the
20 bobbins an entire hank shonld be formed before taking the jvm off; thus at each
** stripping," one bundle is turned off. To facilitate the stripping, one of the rails of
the barrel is made to fall in, and thus slacken the hanks ; care is taken to leave the
lea bands very loose, in order to allow the yam to be spread out in drying and
bleaching. The determinate lenffths of yam, when wound on the reel, are notified by
the ringing of a bell connected with the axle of the barrel. Fig. 857 below shows the
form of sn ordinary hand-reeL
A A ^fig. 867), frvming : b b, reel barrels ; c, box or trough to receive empty
bobbins, &c.; dd, bobbins in position of being reeled; ee, gmde rails, movable so
u to place the leas side by side on the reel; //, bell wheels; g g, bells for each
reel burrel suspended on springs.
268
FLAX.
857
To these hand-reels there are manj oTiJectioiis; for it is erident that the oorrect-
neas of measare depends entirely apon the attention of the reeler, and the stop-
pages arising from the breaking
of a thread or the finishing of a
bobbin interrupt the work of
all the others. These objections
rendered it necessary to attempt
some ameliorations of the sys-
tem by the introdaction of a reel
that should automatically pre-
vent these causes of error. Such
a reel was patented a few years
since, and is now in gener^ use
in Scotland; it is so contrived
as to have, the capacity of stop-
ping itself when a thr^d breaks,
when a bobbin finishes, and
leas and hanks completed ; and
having but four or five bobbins
in one compartment, the stop-
pages affect but few at a time ;
and as this machine can be
worked by less skilftil persons without possibility of error, much saving is effected
both in wages and matenaL The axmezed figure (858) shows the principle of this
improved reeL
A ▲ (^fig, 858X framing ; B reels; c c, pendulums on which are hung the bobbins to
858
be wound off ; D, driving shaft with ratchet wheels opposite to each pendulum, so
that when a thread breaks, the pendulum to which it is attached taWB into the ratchet
wheel, and thus stops it.
The drying of wet spun yams should always, when possible, be done in the open
ur by spreading the hanks upon horizontal poles through them, with anoUier similar
pole resting inside upon their lower extremities, in order to keep them straight If
artificial heat is employed, that from steam or hot water is preferable, and it should
never exceed 90° Fahr., as otherwise the yam is apt to become harsh.
Making up. — By this operation is first produced upon the yams a certain soft-
ness and suppleness, and then the hanks are folded and tied up in conveniently-siaed
packages.
In order to give the yams that soft and mellow feel so agreeable and characteristio
of flax yams, the hanks when brought from the drying are what is called shaken
FLAX.
269
doi»n and pin-worked. This is done by separating a few at a time, and passing them
on to a strong arm of wood fixed to a wall or pillar, when with a heavy baton put
through them, the workman proceeds to stretch the hanks with a sadden check or
jerk, which operation he repeats in two or three places so as to thoroughly straighten
and shake them loose; he tiben, using the same baton as a leyer, twists them lightly
backwards and forwaids till the desired degree of suppleness is obtained. A brush is
sometimes used to aid the straightening and separating, as well as to increase the
gloss on the yam. The hank or hanks will then be found to have assumed a flat
allele, as on Uie reel, which fiusilitates their folding with a dexterous twist by their
middle, when they are laid in square piles upon a table with their twisted folds one
upon another. They are maintained in the perpendicular by a few supports fixed in
the table. Sometimes these packages, which, according to the siaes of the yam, con-
tast of from ^ of a bundle to 5 or 6 bundles, are bound together by some of their own
hanks, but sometimes by cords in three or four places of their length. It is, however,
better to employ a bundling press than an ordinary table, as 3ie yam can then be
made up more solidly, thus both improving its appearance, and causing it to occupy
less space for packing and stowage. The bundling presses are made upon the same
principle, but on a smaller scale, for making up the small packets in which sewing
threads are generally presented for sale, and are upon the following oonstruction
(%i. 859, 860).
859
860
s
E
&
U
s
D
D
(1
cc-v:
r "■
....
....
.-. -
I
,r- 1 c ^
B
r •
■ T
1 0 =
F
1
n
A
A
1
A
H
.u
i /
w
Fig. 859, front view j Fig. 860, profile, a ▲ ▲, frame ; B, table or fiat top of
ihmie; c, rising table ; d d, iron uprights fixed to b; e s, bars hinged at one
end to uprights d d, to shut across the press, and be caught and latched down
by the spring catch L, fixed to the upright d along one side of the press ; f f, racks
for lifting the table c by the pinions on shaft o ; h, crossed levers for turning the
shaft o ; I, ratchet wheel engaging the detent k, and thus retaining the shaft o^ in
any required position, and thus of course maintaining the pressure of table c against
the top cross-bars b.
Weaving^ is the operation by which the yams are combined into textile fabrics,
such as canvass, linens, lawns, drills, damasks, &c, and a great rariety of other deno-
minations of article for use and ornament.
Hitherto the weaving of linens has been carried on by the ancient and well known
hand process, so ancient and so well known as to place the operative practising it
among the worst paid of any other art. Now, however, there are several extensive and
thriving establishments where machinery has taken the place of much squalid misery,
and at much cheaper rates produce to consumers superior articles, and still afford good
payment to the operative. The improvements in power weaving which have led to
this result are not founded upon one or even a few successful inventions or contri-
vances, but are the combination of a great many that have occupied much time to
mature. Many difficulties had to be overcome in the weaving of flax that did not
exist in that of other materials; and for a considerable period the expense of linens
rendered their consumption so limited, as to make their production by power weaving
270 FLAX.
bat a very secondary object, The greatest obstacle of a practical iiatare to die mtro-
duction of the power loom weaying of linens was, the stubbornness or want of elastteit j
in the yam, which caused frequent breakages, and much confusion. In woollen or
cotton goods, if a thread or yam should chance to be a little tighter than the others in
the warp, its elasticity will allow it to come up to the general bearing of the others
when the weft is struck up by the reed; but in linen fh>m the want of that elasticity,
a thread so situated would break, and by crossing some others, cause thoee a^o, if not to
be broken direct by that circumstance, at all eyents to produce an obstruction to the
shuttle that would lead to further mischie£ Hence it was most material in linens to have
such a method of winding the yams upon the warp beams that should insure the greatest
regularity ; but strange to say, that point, though now attained, was at first whoUj
lost sight ot That circumstance, as well as the great mistake of attempting to use
the same looms as are found suitable for cotton, produced so much discouragement in
the earlier attempts as to give rise to a high degree of pr^udiee against the posaibilitj
of success in this undertaking, which may account for the backwardness in which this
branch of the flax manuf^ture was found till quite recently.
The roying machine, called by the ingenious inyentor, Mr. W. K. Westley, of
Leeds, the Sliteb Royinq Fbamv, seems to be a philotophical inductum happilj
drawn from the nature of the material itself^ and accommodated to its peculiar eonsta-
tution. It is remarkable for the simplicity of its construction, and, at the same tim^
for its comprehensiyeness: requiring no nicety of adjustment in its application^ and
no tedious apprenticeship to be able to work it.
It is known that the mucilag|inou8 matter of the plant may be softened by water, and
hardened again by heat; of tms fact advantage is taken, in order to produce a roving
wholly without twist; that is, in the form of a ribbon or sliver, in which the fibres are
held together by the glutinous matter which may be natural to them; or which may,
for that purpose, be artificially applied. The sliver roving, as long as it remains dry,
possesses all requisite tenacity, and freely unwinds from the bobbin, but on becoming
again wetted in the spinning firame, it readily admits, with a slight force, of being
drawn into yam, preserving the fibres quite paralleL
The diagram,^. 861, shows in explanation, that
A, is the drawing roller of the roving
frame in front of the usual comb.
B, the pressing drawing roller,
c, a shallow trough of water.
D, a cylinder heated by steam.
E, a plain iron roller for winding,
r, a bobbin lying loose upon the
winding roller, and revolving upon it,
by the fHction of its own weight
The roving, or sliver, as shown by the
dotted line, after leaving the drawing
rollers, ▲, b, passes through the water, in
the trough c, which softens the glnteo
of the fibres : and then it is carried round
by the steam cylinder d, which dries it,
and delivers it hard and tenacious to the
bobbin f, on which it is wound by the
action of the roller b.
This is the whole of the mechanism required in prodncmg the sliver roving.
All the complex arrangements of the common cone roving are superseded, and
the machine at once becomes incomparably more durable, and easier to man-
age ; requiring only half the motive power, and occupying only half the room. A
frame of 48 bobbins is only 6 feet long, iad affords rovings suflicient to supplj 1200
spinning spindles.
This machine, though here described, is but little used, bemg capable of but very
limited application.
Combe of Belfhst has lately introduced an improvement in the roving tnme. It
consists in the application of a peculiar expanding pulley, instead of £be cones, or
discs and runners which have hitherto been always i^€^ for the purpose of regulating
the *' take-up ** of the bobbins. It is evident that a strop of 2 or 3 in. broad, working
over the cones, placed with the small end of one opposite the large end of the other
is an imperfect and rude mechanical contrivance, and that there must be a constant
straining and stretching of the belts. There is the same imperfection attending the
disc and ranners. The expanding pulley is free from these objections, as its acting
suifAce is a line ; and therefore it works with the greatest accuracy, while it is also
a great simplification of the machine generally. In rovings for fiax and tow it is
M k large nsmbar of
The fbHowing sketch ihowi ihe UT*ii[;em«it of the mtchioery In the mort
Importaot roomi id amodemftax mill of 7000 to 8000 apindles, capable of produciag,
weeklj.aboat I900bnndle« of liue yani, No. li'i to ISO'i; and about 700 bondlei of
tow jwn. So. 10*1 to 10'a.
r«ttii«c(7(tain of long line maehfaieiyftr No.S6'tto 70*i| twoafftcowof
ent line macluDerr tbr No. 10*1 to ISi^i i and thraa artteiiu of tow nuohuMrr for
Mo. io-a to «*«.
The bnildiDg ii SS ftet wide and ISS feet long; which ia a rerj snitable andeon-
Tenient tUe, and which mdiuita of the moat economical amngement of the maohinerT.
The fallowing ia a deacription of the machinea ihown in the preparing loom i —
A X, two of Basier's patent iheet baeUing machine* fw long tow.
272
FLAX.
D D, are two breaker cards, 4 feet diameter x 6 feet wide.
E, lap machine.
864
r F F, are three finisher cards 4 feet diameter x 6 feet wide, with P. Fairbaim and
Co/s patent rotary gill drawing heads attached.
G o, are two patent rotary gill drawing frames for long tow, 12 sliyers each.
H H, two ditto regulating roving frames, 48 spindles each, for long tow.
J, is a screw gill second drswing frame of 3 heads for cut line tow.
K, is a screw gill third drawing frame of 3 heads for cat line tow.
L, a screw gill regulating roving frame of 72 spindles for cut line tow.
M M H, are three long line first drawing frames or spreaders of 4 bosses each.
N N N, are three long line second drawing frames of 2 heads each.
o o o, are three long line third drawing frames of 2 heads each.
p p p, three long line regulating roving frames, 60 spindles each.
Q Q, are two cut line spreaders of 4 bosses each.
B K, two cut line second drawing frames, 2 heads each.
8 8, two cut line third drawing frames, 2 heads each.
T T, two cut line regulating roving framies, 72 spindles each.
The spinning room contains 34 spinning frames of 184 to 244 spindles each,appor*
tioned to the several systems as described below.
I. System of long line machinery for spinning No. 25's to 40*s.
1 Baxter's patent sheet hackhng machine, 6 tools.
1 spreader or first drawing frame, 4 bosses.
1 second drawing frame, 2 heads, 4 bosses each.
1 third drawing fhune, 2 heads, 6 bosses each.
1 patent disc regulating roving frame, 60 spindles, 10 spindles per head, 8 inches
X 4 inches bobbin.
5 spinning firames, 2} inches pitch, 200 spindles each, 1000 spindles.
The production of this system is about 66 bundles, or say, 420 lbs. of Na 30*s yam
per day.
II. Two systems of long line machinery for Na 40*s to 60's.
1 Baxter's patent sheet hackling machine, 8 tools.
2 spreaders or first drawing frames, 4 bosses each.
2 second drawing frames, 2 heads of 6 bosses each.
2 third drawing frames, 2 heads of 8 bosses each.
2 patent disc regulating roving frames, 60 spindles each, 12 spindles per head, 6
inches x 3^ inches bobbin.
10 spinning frames, 220 spindles each, 2} inches pitch, 2200 spindles. Production
about 130 bundles, or 472 lbs. of No. 55's yam per day.
III. Two systems of three cut line machinery for No. 40*s to 120*s (one for 40*s
to 70*8, and one for 70*s to I20*s).
1 flax cutting machine.
1 P. Fairbaim and Co.'s patent double line of holder hackling machine,
2 spreaders or first drawing frames, 4 bosses each,
2 second drawing frames, 2 heads each, 6 slivers per head.
2 third drawing frames, 2 heads each, 8 slivers per head.
2 patent disc regulating roving frames, 72 spindles each, 12 spindles per head,
• 6 X 3^ inches bobbin.
5 spinnmg frames, 220 spindles each, 2^ inches pitch, « 1100 spindles.
5 spinning frames, 244 spindles each, 2^ inches pitch, » 1220 spindles.
Production about 65 bundles or 236 lbs. of No. 58's jam per day, and about 50
bundles or 105 lbs. of Na 95's yam per day.
FLAX. 273
IV. Tto tjtttmi of long tow nuwbiiicrj'for No. 10's to as's.
1 breiker csrd, 4 feet diuDcter, 6 feel wide, doffed bj rollen.
1 Up machine.
S flniihercardi,4 feet 1 6 feet, with F. Fairbaim & Ca's patent roiar; gill drswing
framea attached.
S patent rotary gill drawing framei, 1! aliTcn each.
3 pUest rotarj gill diic regulating roviag-fVainea, 4B spindlel each, a ioches x 4
inche* bobbin.
a ipinning frame*, 1B4 Bpindlei each, 3 inchea pitch for Tfo. ID'i to 18's — 55S
ipindle*.
3 ipinniDg fhunel, 200 ipindle* each, Sj iochei pitch for No. 16'i to SS'a — 600
iplndlei.
Prwluction abont 39 bnodlea, or 48B Ibe. No. 1 e'a per day, and about 30 bundlea
or 312 Iba., No. 25't per da^.
V. One lyitem of cut tow machinery for No, SB't to 40'a
1 Breaker card, 4 feet diameter. 6 feet wide, doffed bj comb*.
I Finliber card, with P. Fairbaira & Co.'i patent rotary gill drawing frame at-
tached.
1 Screw gill aecond drawing frame. 3 headi each, 4 bocsea per bead.
1 Screw gill third drawing tVame, 3 headg each, S bossei per head.
1 Sctcw gill patent diac regulating roving frame, TS apindtea, 13 apindlea per head,
' X 3^ inches bobbina.
.linnin; '
Produclioi
The reeling ii generally carried on iu the attic above the apinning n ,
liamber of reela required ii about the aame as the number of apinning framea.
Sundmrji eiriB,
There are 3300 ipindlet long line, prodneing 19S bnndlet, or, 890 lb*, of yam per day.
1IS9 „ long tow, „ 78 „ 800 „
SSaO „ 3 cut line, „ lis „ 940 „
6ao_ „ cnttow, „ ^ „ 240 „
7332 apindlea 425 bandies S270tb«. of yarn perday.
The waste in line apinning ii generally abont 10 per cent., and in tow apinning abonl
as per cent, ao that the quantity of raw flax required to prodnce the above nated
qnaolity of yarn would be ggj
about 30 cwti. of flax for long
line and long tow apinning,
and about 6 cwts. of flax for
ent line and cat tow apinning.
Fuix Weatiko Loom
VOB HeATT FlBBtCB. —
A^±,fig:865, 866,f>ameof
loom ) B, beuu on which
the yam for warp ia wound ■,
c, cloth recoviog beam j
D, driving polleya and fly-
wheel ; H, hand rail for aop-
porting the reed : w, aworda
of anpporta of going part ; o,
picking aticka for drivipg
the ahnttle ', h leather (traps
tor connecting the picking
aticka with their actaating
levers l> i m, n, jaws of a
clamp to eanae the retaining
ftiction un the collan of the
beam b, by which fnclion
the qoantily of weft ia re-
gulated ; o. end of lever,
bearing the weight by which
the jawa are brought to-
gether 1 e, lever, keyed at -
one end to the npright shaft q, and connected with tbe other to the ftatcnmi of the
weighted lever o ; R, lever, one end of which ia alio keyed to the npright shaft a, and
the other ia provided with a wood scJe, and ia preaaed by a alrong apring against the
Vol. 1L 'J'
274 FLINT.
jam voDnd npoD tlic beam b. It will be seen that, ai tlic yikrn ia takm trff Ibe bean
n, and its diameter consequentlj redocefl, the lever p inOTei the fnlerum of the
veiglited lerer o. and ihua regulates (he pressure npon (he clampa M and N, caiuing
an equal teueiou upou the jam from the full (o the empty beam ; n, treddles, actuated
by the cams b, drireo by the nhMlg e, d, e, tronf (he picking shaft/; g g, ahuitle
bozaa at each eod of tbe going part ; h k, arrangement of leTera to cooduct eqnaUj
666
each end of the gears i r. This loom has nl&o, in addition to the ordinarj' Mopping
arrangement connected with the shuttle, one alio for relaxing the reed in ease the
shuttle should be arrested in its course acroBS the varp, vhereby the danger, ordinarily
incurred by chat accident, of breaking many threads in the warp, ia aroided: it will
also be seen (hat the bands called picking bands are eupereeded by the ends of the
picking leTcrs slriking the shuttle direct; thus, by these improveDieDlB, drills «re
currently woven in this loom at the rate of 120 to 130 picks per minute.
Of late extensive trials have been made to adapt the power-loom to the weaving of
light linen fabrics. Previonsly it bad been found that while coarse and strong flax
^rics, inch as those made at Dundee, Arbroath, &c., in Scotland, and the drills iDude
U Barosley, could be produced by power as well and more cheaply than by hand, yet that
the lighter fabrics, such as shirtings, cambrics, lawns. &c.. would not bear tbe strain of
the power-loom, or at all events that to make them of as good appearance as by the
hand-loom the manufbctnrer required to employ a dearer article of yam. and so found
that be could not compete with his neighbours who had hand-loom weavers. The
■carcity of the latter in Ireland, during the last three or foar years, and the advance
in wages caused by the growing prosperity of the country, has directed the serioos
attention of the trade to the matter, and therefore mannfacturers and machine mnfcers
have each zealously sought to remedy the defects that existed in the power-loom, as
regards its application to the weaving of light linen i^bricG, and tof^ve repeated trials
to new inventions. The consequence has been that, while foor yean ago there were
only in Ireland flfty-two power- looms making linens of any kind, there are now nearly
3U00, and these produce all kinds of flaxen fabrics of good quality, and fairly re-
mnneralive to the manufacturer. This bninch of the manuf^lure is, however, a*
yet in an embryo state.
A« respects other details of the snhsequent processes which linens undergo before
they are placed in the market, and also the general statistics of tbe entire tr»de in
imports and exports, see BLGAcamo, Linem, &c J. M'A.
FLAX SKED. See Linskki),
FLINT. (Pierre a/iuit Fr.i Fcarnlein, Germ.) Tbe fractureof this foswl isper-
feetly concboidal, sometime* glossy, and sometimes dull on the surhce. It is very
hard, bat breaks easily, and affords very sharp-edged splintery ft^gments ) whence it ia
FLINT. 276
a stcme which strikes moet copious sparks with steel. It is feebly tnnslacid, has so fine
and homogeneous a texture as to bear polishing, but possesses little lustre. Its colours
are Tery Tarions, but ncTer yirid. The blackish-brown flint is that usually found in
the white chalk. It is often white and opaque, loses its colour in the fire, and becomes
greyish-white, and perfectly opaque. Flints occur almost always in nodules or tuber-
cular concretions of rarious and very irregular forms. These nodules, distributed
among the chalk, alongside of one another and almost in contact, form extensive beds ;
interrupted, indeed, hj a multitude of yoid spaces, so as to present, if freed from the
earthy matter in which they are imbedded, a species of network with meshes, very
irregular both in form and dimension.
The nodules of silex, especially those found in the chalk, are not always homo-
geneous and solid. Sometimes there is remarked an organic form towards their
centre, as a madrepore or a shell, which seems to hare served as their nucleus ;
occasionally the centre is hollow, and its sides are studded over with crystals of
quartz, carbonate of iron, pyrites, concretionary silex or calcedony, filled with pulve-
rulent silica nearly pure, or silex mixed with sulphur ; a very singular circumstance.
Flints are observed to be generally humid when broken immediately after being dug
out of the ground; a property which disappears after a short exposure to the air.
When dried they become more brittle and more splintery, and sometimes their surfaces
get covered at old fractures with a thin film or crust of opaque silex
Flints calcined and ground to a powder enter into the composition of all sorts of fine
pottery ware.
An important application of this siliceous substance was in the formation of gun-
flints, for which purpose it was cut in a peculiar manner. The following characters
distinguish good flint nodules from such as are less fit for being manufactured. The
best are somewhat convex, approaching to globular ; those which are very irregular,
knobbed, branched, and tuberose, are generally full of imperfection. Good nodules
seldom weigh more than 20 pounds ; when less than 2, they are not worth the working.
They should have a greasy lustre, and be particularly smooth and fine grained The
colour may vary fh>m honey yellow to blackish-brown, but it should be uniform
throughout the lump, and the translucency should be so great as to render letters legible
through a slice about one-fiftieth of an inch thick, laid down upon the paper. The
fracture should be perfectly smooth, uniform, and slightly conchoidal ; the last property
being essential to the cutting out of perfect gun-flints. Although flint locks are now
but rarely employed, the process of cutting Uie flints to shape possesses much interest.
Four tools are employed by the gun-flint makers.
First, a hammer or mace of iron with a square bead, from 1 to 2 pounds weight, with
a handle 7 or 8 inches long. The tool is not made of steel, because so hard metal
would render the strokes too harsh, or dry, as the workmen say, and would shatter
the nodules irregularly, instead of cutting them with a clean conchoidal fracture.
Second, a hammer with 2 points, m^e of good steel well hardened, and weighing
from 10 to 16 ounces, with a handle 7 inches long passing through it in such a way
that the points of the hammer are nearer the hand of the workman than the centre of
gravity of the mass.
Third, the disc hammer or roller, a small solid wheel or flat segment of a cylinder,
parallel to its base, only two inches and a third in diameter, and not more than 12
ounces in weight It is formed of steel not hardened, and is fixed upon a handle 6
inches long, which passes through a square hole in its centre.
Fourth, a chisel tapering and bevelled at both extremities, 7 or 8 inches long, and 2
Inches broad, made of steel not hardened; this is set on a block of wood, which serves
also for a bench to the workmen. To these 4 tools a file must be added, for the pur-
ix>se of restoring the edge of the chisel from time to time.
After selecting a good mass of flint, the workmah executes the four following oper-
ations on it.
1 . He breads the block. Being seated upon the ground, he places the nodule of flint
on his left thigh, and applies slight strokes with the square hammer to divide it into
smaller pieces of about a pound and a half each, with broad surfaces and almost even
fractures. The blows should be moderate, lest the lump crack and split in the wrong
direction.
2. He cUavee or chips the flint The principal point is to split the flint well, or to
chip off scales of the length, thickness, and shape adapted for the subsequent formation
of gun flints. Here the greatest dexterity and steadiness of manipulation are necessary ;
but the fhu!ture of the £nt is not restricted to any particular direction, for it may by
chipped in all parts with equal facility.
The workman holds the lump of flint in his left hand, and strikes with the pointed
hammer upon the edges of the great planes produced by the first breaking, whereby
the white coating of the flint is removed in small scales, and the interior body of the
T 2
276 FLOOR-CLOTH MANUFACTURE.
flint is laid bare ; after which he continues to detach similar scalj portioDS from the
clean mass.
These scaly portions are nearly an inch and a half broad, two inches and a half
long, and about one-sixth of an inch thick in the middle. They are slightly conTez
below, and consequently leave in the part of the lamp from which they were separated
a space slightly concave, longitudinally bordered by two somewhat projecting straight
lines or ridges. The ridges produced by the separation of the first scales must natarall j
constitute nearly the middle of the subsequent pieces ; and such scales alone as hare
their ridges thus placed in the middle are fit to be made into gun-tlints. In this
manner the workman continues to split or chip the mass of flint in various directioBs,
until the defects usually found in the interior render it impossible to make the requi-
site fractures, or until the piece is too much reduced to sustain the smart blows bj
which the flint is divided.
3. He/ashions the gun flints. Five different parts may be distinguuhed in a gun-
flint 1. The sloping facet or bevel part, which is impelled against the hammer of
the lock. Its thickness should be from two to three twelfths of an inch ; for if it
were thicker it would be too liable to break ; and if more obtuse, the scintillations
would be less vivid. 2. The sides or lateral edges, which are always somewhat
irregular. 3. The back or thick part opposite the tapering edge. 4. The under
surface, which is smooth and rather concave. And, 5. The upper face, which has a
small square plane between the tapering edge and the back, for entering into the upper
claw of the clock.
In order to fashion the flint, those scales are selected which have at least one of the
above-mentioned longitudinal ridges } the workman fixes on one of the two tapering
borders to form the striking edge, after which the two sides of the stone that are to form
the lateral edges, as well as the part that is to form the back, are successively placed
on the edge of the chisel in such a manner that the convex surface of the flint, which
rests on the forefinger of the left hand, is turned towards that tool Then with the
disc hanmier he applies some slight strokes to the flint just opposite the edge of the chi-
sel underneath, and thereby breaks it exactly along the edge of the chiseL
4. The finishing operation is the/rimmin^, or the process of giving the flint a smooth
and equal edge ; this is done by turning up the stone and placing the edge of its
tapering end upon the chisel, in which position it is completed by five or six slight strokes
of the disc hammer. The whole operation of making a gun-flint, which I have used
so many words to describe, is performed in less than one minute. A good workman
is able to manufacture 1000 good chips or scales in a day (if the flint balls be of good
quality), or 500 gun -flints. Hence, in the space of three days, he can easily cleave and
finish 1000 gun-flints without any assistance.
Flints form excellent building materials ; because they give a firm hold to the mortar
by their irregularly rough surfaces, and resist, by their nature, every vicissitude of
weather. The counties of Kent, Essex, Suffolk, and Norfolk contain many substantial
specimens of flint-mastmry.
FLOCK and FLOCKS. The first is finely powdered wool, used when dyed of
various colours to prepare paper hangings.
The second is a name given to the refuse or waste of cotton and wool, and is used
for stuffing mattresses.
FLOCK PAPER. Paper prepared for walls by being sized in the first inst^ce,
either over the whole surface or over special parts, constituting the pattern only, and
then powdering over it flock or powdered wool which had been previously dyed.
FLOOKAN or FLUKAN. The name given by the Cornish miners to veins filled
wholly wich clay. This is usually applied to such veins or lodes as are at right angles,
or nearly so, to the true metalliferous lodes.
FLOOR CLOTH MANUFACTURE has become of late years a very large
branch of trade. The cloth is a strong somewhat open canvas, woven of flax with a
little hemp, and from 6 to 8 yards wide, being manufactured in appropriate looms,
chieflv at Dundee. A piece of this canvas, from 60 to 100 feet in length, is secured
tight m an upright open frame of oaken bars, in which position it is brushed over
with glue size, and rubbed smooth with pumice stones ; it next receives the founda-
tion coats of paint, 2 or 3 in number, first on the back side, and then on the front.
The foundation paint, made with linseed oil and ochre, or any cheap colouring matter,
is too thick to be applied by the brush, and is therefore spread evenly by a long narrow
trowel, held in the right hand, from a patch of it laid on just before with a brush in the
left hand of the workman. Each foundation coat of the front surface is smoothed by
pumice stone whenever it is hard enough to bear the operation. When both sides are
dry, the painted cloth is detached from the frame, coiled round a roller, and in this
Ftate transferred to the printing room, where it is spread flat on a table, and variously
figured and coloured devices are given to it by wooden blocks, exactly as in the block
FLOUR.
277
printing of calicoes or papers. The blocks of the floor cloth mannfaetnre are formed
of two layers of white deal and one of pear tree timber, placed with their grain cross-
ing one another alternately. There is a block for each colour in the pattern, and in each
block those parts are cat away that correspond to the impressions given by the others ;
a practice now well understood in the printing of two or more colours by the press.
The fi&ces of the blocks are so indented with fine lines, that they do not take up the
paint in a heary daub fVom the ^t cushion on which it is spread with a brush, but in
minute dots, so as to lay on the paint (somewhat thicker than that of the house
painter) in a congeries of little dots or teeth, with minute interstices between. Ap-
plied in this way, the Tarious pigments lie more evenly, are more sightly, and dry
much sooner than if the prominent part of the block which takes up the colour were
a smooth surface. The best kinds of floor cloth require from two to three months
for their production.
From the use of the sulphate of barytes with the white lead, sometimes to the
extent of 75 per cent of the former, not merely in the foundation paint, but in the
subsequent colours with which the canvas is painted, there is a very general com-
plaint that the floor cloths for halls, &c., where they are necessarily exposed to
washing, very soon lose their colours and become bare, the barytes washing out, and,
of course, removing at the same time the lead and other colours. See White Lead^
FLORAN. A mining term ; tin ore scarcely perceptible in the stone ; tin ore
stamped very small.— JVyce.
FLOSS, of the puddling furnace, is the fluid glass floating upon the iron produced
by the vitrification of the oxides and earths which are present See Iron.
FLOSS-SILK (Filo$elle, Bourre de wie, Jieuret, Fr.) is the name given to the
portions of ravelled silk broken off in the filature of the cocoons, which is caided like
cotton or wool, and spun into a soft coarse yam or thread, for making bands, shawls,
socks, and other common silk fabrics. The floss or fieuret, as first obtained, most be
steeped in water, and then subjected to pressure, in order to extract the gummy matter,
which renders it too harsh and short for the spinning-wheel. After being dried it is
made still more pliant by working a little oil into it with the hands. It is now ready
to be submitted to the carding engine, and it is spun upon the flax wheel.
The female peasants of Lombardy generally wear clothes of homespun floss silk. Of
late years, by improved processes, fine fkbrics of this material have been produced,
both in England and France. M. Ajac, of Lyons, manufactures a variety of scarfs
and square shawls of bourre de «oie, closely resembling those of cachemire.
FLOUR. The finely ground meal of wheat, and of any other corns or cereaUa, See
Bread.
Since the analyses of grains represent the total chemical constituents of the flour,
and the cell in which it is contained, a few analyses fh>m the researches of Way and
Ogston are given : —
Whiat.
Barut.
Hopeton.
Red Straw.
Old Red
Lammat.
Chavalier.
Unknowa
MoldaTia.
Potassa - - -
30-32
29-75
82*46
27-43
21-14
31-55
Soda
0-07
0-64
4-63
0-05
. -
1-06 "
Lime ...
2-51
3-27
3-21
2 79
1-65
1-21
Magnesia
12-38
13-75
9-56
8-67
7-26
10-17
Sesquioxide of iron -
0*08
0-23
2-06
0-09
2-13
1-02
Sulphuric acid
0-18
0-60
0-32
2-72
1-91
0-27
Silica . . -
3-60
2-14
5-46
23-60
30-68
24-56
Phosphoric acid
49-22
49-58
40-67
2601
28-53
28-64
The produce of one quarter of wheat weighing 504 lbs. is, according to Mr. Hard of
Dartford —
Flour - - - - - - - 392lb8.
Biscuit or fine middlings > - - - 10
Toppings or specks .... - 8
Best pollard ..... 15
Fine pollard - . . - - 18
Bran and coarse pollard .... 50
Loss .--.-.- 11
504 lbs.
T3
278 FLOWERS, ARTIFICIAL, MANUFACTURE OF.
Vauqaelin has given the following as the results of his examination of -wheat
flour : —
Starch
Gluten
Sugar
Gum
Bran
Water
French.
71-49
10-96
472
3*82
10-00
Odetca
hard.
56-5
14*55
8*48
4-90
2-30
12-00
Odena
•oft.
6200
1200
7-66
5-80
1-20
10-00
«-_j m I Inferior
Parii flour. jioa,.
72-8
10-2
4-2
2-8
10-0
67-78
9-02
4-80
4-60
12-00
Adulterations of, to detect — The first method is by specific gravity. If potato flour
be added, which is frequently done in France, since a Tessel which contains one
pound of wheat flour will contain one pound and a half of the fecula, the proportion of
this adulteration may be easily estimated. If gypsum or ground bones be mixed with
the flour, they will not only increase its density still more ; but they will remain after
burning away the meal as ashes.
The second method is by ascertaining the quantity of gluten which the snspeeted
sample will afford, see the article Bread. The two following chemical criteria may
also be employed.
1st. Nitric acid has the property of colouring wheat flour of a fine orange yellow,
whereas it affects the colour neither of fecula nor starch.
2nd. Muriatic acid colours good wheat flour of a deep violet, but dissoWes fecola
or starch, and forms with it a light and colourless viscous fluid, decomposable by
alkalies.
Sulphate of iron renders an infusion of pure flour somewhat yellow, and imparts a
bottle green to that which is adulterated with bean meal. — (^Lcusaigne.) Nitric acid
and ammonia poured snccessirely on good flour shows nothing remarkable ; but bean
meal strikes a deep red colour. — (/>cmny.)
The amount of ash left by the flour has been proposed by Lonyet as a test of its
purity. He says, '* Wheat flour yields on the average 0*8 per cent ; rye flour, IH) ;
bean and pea meal, 3 ; linseed meal, 10 per cent of ash.'*
FLOWERS. The name formerly given to those substances which were obtained by
sublimation ; as the flowers of sulphur, the flowers of Benjamin, &&
FLOWERS, ARTIFICIAL, MANUFACTURE OF. The art of representing
by flowers, leaves, plants, &c, vegetable nature in her ornamental productions, consti-
tutes the business of the artificial florist The Italians appear to have been the first
people in Europe who excelled in the art of making artificial fiowers ; but of late
years the French have been most ingenious in this branch of industry.
Ribbons folded in different forms and of different colours were originally employed
for imitating flowers, by being attached to wire stems. This imitation soon gave way
to that by feathers, which are more delicate in texture, and more capable of assuming a
variety of flower-like flgures. But a great difficulty was encountered in dyeing them
with due vivacity. The savages of South America manu&cture perfect feather flowers,
derived from the brilliant plumage of their birds, which closely resemble the products
of vegetation. The blossoms and leaves are admirable, while the colours never fiide.
The Italians employ frequently the cocoons of the silk- worm for this purpose ; these
take a brilliant dye, preserve their colour, and possess a transparent velvety appearance,
suitable for petals. Of late years, the French have adopted the flinest cambric for
making petals, and the taffeta of Florence for the leaves. M. de Bemardiere employs
whale^ne in very thin leaves for artificial flowers ; and by bleaching and dyeing them
of various hues, he has succeeded in making his imitations of nature to be very re-
markable.
Gutta percha dissolved in benzole, and freed from all impurities, will when spread
out on a ^eet of glass dry into a beautifully white and delicate film, of great strength,
and capable of receiving any colour. This has been employed in Paris in the manu-
facture of flowers. Vegetable parchment (paper prepared by the action of sulphuric
acid) has been employed for the same purpose in this country. See Vbgetaiile
Parchment.
The colouring matters used in flower dyeing are the following : —
For red ; carmine dissolved in a solution of carbonate of potash.
For blue ; indigo dissolved in sulphuric acid, diluted and neutralised in part by
Spanish whitening.
For bright yetlow ; a solution of turmeric in spirit of wine. Cream of tartar
brightens Sii these colours.
FLUOR SPAR. 279
For violet ; archil, and a Uae bath.
For lilac ; archiL
Some petals are made of yelvet, and are coloored merely by the application of the
finger dipped in the dye.
FLUATES, more properly fiuandtM. (Eng. and Fr. ; Fhut&urey Germ.) Com-
poan4s of flaorine and the metals ; as fluor ^ar, for example^ which consists of fluorine
and calcium.
Fluor spar consists of —
Fluorine .... 48<7
Calcium .... 5i>3
Cryolite —
Fluorine .... 54*2
Sodium .... 83*8
Aluminium .... 13*0
ChioUte —
Fluorine - - - - 57-53
Sodium .... 28*78
Aluminium .... 18*69
FluelUte is fluorine and aluminium, a rare mineral found at Stennagwyne in Com-
walL
FLUKES. See Anchor.
FLUORESCENCE, the name given to a peculiar phenomenon rendered evident
by many crystals of fluor spar. If we look through a crystal of fluor spar it will ap-
pear yellow or green as the case may be ; now if we look at it, the light falling upon
the sur&ce on which we look, it will appear beautifully blue or purple. Mr. Stokes,
to whom we are indebted for a very exact examination of the whole of the phenomena
of this class, refers this effect to an alteration of the refraction of the ray by the first
surface upon which itfiiUs. Sir John Herschel first drew attention to this peculiar con-
dition as exhibited in a solution of sulphate of quinine in water slightly acidulated
with sulphuric acid. Here we have a perfectly colourless solution when we look
through it, which sends back to the eye fine blue rays wben we look at the surface
on which the solar rays falL Sir John Herschel referred this to epipolic dispersion,
or dispersion from the first surface of the fluid on which the light fell. There are
many substances which appear to possess this property of altering the refraction of
rays, or are fluorescent. Beyond this brief explanation, we cannot afford space in this
dictionary to deal with the subject We must refer those interested to the Philoso-
phical Transactions, in which Mr. Stokes's communications appeared.
FLUORINE. The elementary base of fluoric acid, which has never yet been
isolated.
The power of liberating a principle f^om fluor spar, which would etch glass
was known as far back as 1 670 ; Scheele, in 1 771, examined fluoric acid, and regarded
it as an oxygen compound with an unknown element Ampere, in 1810, determined
the fluoric acid was a compound of hydrogen and fluorine.
Fluorine combines with most of the metals, and with hydrogen, boron, silicon,
sulphur, and phosphorus ; with chlorine^ bromine, iodine, and oxygen it exhibits no
tendency to unite.
Symbol, F; equivalent 19*
FLUOR SPAR, (Chaux JluaUe, Fr. ; Spaih fluor. Germ.) This mineral often
exhibits a variety of vivid colours. It crystallises in the cubic (monometric) system,
with regular octahedral and tetrahedral cleavages ; spec. grav. 8*14 to 3*19 ; H »4'0;
scratches calc spar, but is scratched by a steel point ; usually phosphorescent with
heat ; at the blowpipe decrepitates and fuses into an opaque bead ; acted on by the
acids with disengagement of a vapour which corrodes glass ; its solution affords pre-
cipitates with the oxalates, but not with ammonia. Its constituents are, fluorine*
48*7 ; calcium, 51*13 in 100.
Fluor spar occurs subordinate to metallic veins ; as to those of lead, in Derbyshire
and Cumberland ; of tin and copper, in Cornwall, and in Saxony and Bohemia ; but it
is found also in masses or veins, either in crystalline rocks, associated with quartz, ba-
rytes, &&, as in Auversne, Forez, Vosges, Norberg in Sweden; Norway ; Petersburg;
Gourock, in Scotland, &c ; or among secondary limestones, slates, and sandstones,
in Derbyshire, Cumberland, Cornwall, and New Jersey. It exists also in the amyg-
daloids of Scotland, and in the volcanic products of Monte Somma at Vesuvius. Tbe-
variously coloured specimens, called Derbyshire spar, are worked upon the turning
lathe into vases and other ornamental objects.
A very beautiful variety, which has been much used for ornamental purposes,
known from its colour as ^ Blue John," has been obtained from Tray Cliff near
T4
280 FORGE.
Castletoii, Derbyshire. The beaatiful colour of the nataral flaor has been taecesg-
folly imitated by exposing some of the common varieties to heat.
Auor spar is employed to a considerable extent in the production of hydroflooric
acid and for etching on glass. It is also used by lead smelters as a flux. The beautifiil
phenomenon oi fittoreacence is so named flrom the &ct that many of the flnor span
hare the power in a high degree of thus affecting the rays of light See fLuo*
&E8CENCE.
FLUVI ATILE (Jiuvius, a river), belonging to a river.
FLUX (Eng. and Fr. ; Fiusa, Germ.) signifies any substance capable of promoting
the fusion of earths or metallic ores by heat White flux is the residuum of the defla-
gration, in a red hot crucible, of a mixture of two parts of nitre and one of cream of
tartar. It is in fact merely a carbonate of potash. Black flux is obtained when equal
parts of nitre and tartar are deflagrated. It owes its colour to the carbonaceous matter
of the tartaric acid, which remains unconsumed ; the quantity of nitre being too small
for that purpose. The presence of the charcoal renders this preparation a convenient
flux for reducing calcined or oxidised ores to the metallic state. Limestone, flnor spar,
borax, and several earthy or metallic oxides, are employed as fluxes in metallorgy.
See Metallurgy.
FLY POWDER. Under this name they sell on the continent the black coloured
powder obtained by the spontaneous oxidisement of metallic arsenic in the air. Va-
rious preparations of white arsenic are used for the same purpose in this country.
King's yellow is much used ; it should be made by boiling together sulphur, lime,
and white arsenic, but much that is sold is merely arsenic and sulphur mixed.
Objecting on principle to the familiar use of arsenic and dangerous substances,
a preference may be given to a substitute for the above, made by boiling quassia chips
into a strong decoction and sweetening with loaf sugar. This seems to have deadly
power over the flies, who can scarcely quit the liquid without imbibing a deadly
potion, and they are seen to fall from the ceilings and walls of the rooms soon after-
wards. Many of these compounds for killing flies are supposed by their odour to
attract flies into the rooms.
The inconvenience to manufacturers and others from flies, ma^ be obviated in many
cases where apartments are required to be kept as free as possible from them, by re-
ference to facts recorded by Herodotus, of fishermen surrounding themselves with
their nets to keep off the gnats. We are indebted to William Spence, Esq. F.R.S., for
some very curious particulars respecting the common house fly communicated in a
paper to the Entomological Society. The common house fly, will not in general
pass through the meshes of a net The inhabitants of Florence and other parts of
Italy are aware of this fact, and protect their apartments by hanging network up at
the windows, thus at all times the doors and windows may be kept wide open by hang-
ing a light network over the aperture ; the meshes may be of considerable wid£,
say enough for several flies on the wing to pass through, and no fly will attempt to pass,
unless there be a strong light (another window opposite, or reflection from a looking-
glass). A knowledge of this simple means of protection from flies on the wing may
prevent inconvenience from these intruders, and obviate the necessity for poisons to
destroy them. — T. J. P.
FODDER, is the name of a weight by which lead and some other metals were sold
in this countiy ; but it is now rarely used. It varied in its amount in different parts
of the kingdom, being 19^ cwts. at Hull ; 21 cwts. at Newcastle ; 22 cwts. at Stockton ;
24 cwts. in Derbyshire.
FOILS. Thin sheet copper silvered and burnished, and afterwards coated with trans-
parent colours mixed widi isinglass, emploved by jewellers to improve the brilliancy
of pastes and inferior stones. The foil is mclosed in the setting, and entirely covers
the back of the stone, to which it imparts much of its own brilliancy.
FOILS. Thin leaves of metal, usually allocs, of various colours, employed prin-
cipally for heightening the brilliancy of artificial gems.
FONDUS, is the name given by the French to a particular style of calico printing
resembling the rainbow, in which the colours are graduated or melted {fondus) into
one another, as in the prismatic spectrum. See Calico Pbintimo for a description
of the process.
FOOD. See NuTRrrioif.
FOOTW ALL, a mining term. The '* wall " or side of the rock under the mineral
vein : it is as commonly called the underlaying wait
FOOTWAY, a mining term. The ladders by which the miners descend and ascend.
FOROE (Eng. and Fr. ; Feuer, Germ.) is the name either of the furnace, where
wrought iron is hammered and fashioned with the aid of heat, or the great workshop
where iron is made malleable. The former is called a smith's forge, the latter a
shingling miU. See Ibon.
FOUNDING.
281
Fig. 867 repreMDU a portable truck forge of a yerj commodioo* coDitroction.
A ii the c7lindric leather belloiri, prewed down by a helical apring, and worked bj*
meam of the huidle st b, which
moret ihe horizontel shaft c, with
it* two attached semicircalar
kTen and chaJni, d ia the pipe
-which condncti the blait to the (J
Dozile at K. The hearth may he li
coTered with a thin fire-til? or >|
with cinders, r is a vice fixed f
to Ihe ittong reclaognlar fVame. i
Tbi« appftratns aniwers all the
ordinarj parpoaee of a nnilh's
tbrge i and is peculiarly adapted
to ships, and to the execation of
engineering Jobs npon railwajs,
or in the conntry. The height
is 9 feet 6 iochesi the length ii
S feet 9 inches ; the width S feel.
Wei^t about 2 cwt
Holizapffel describes another <
portable forge of his own con-
Mmction, poMes^g many advan-
tages.
With the monipnlatiotis of the
fiirge, it is Dot the province of this
work la deal.
FORK, a mining term. A mine
" water in fork," when all the water is arawn oqi.
FORMATION. A geological term, which is used to ugDlff a group of rocks, r^
fared to a common origin, or belocging to the somo period.
FORMIATEa. Componnds with fomiic add. Sre Urt'M Dictionary of Chtntiitry.
FORMIC ACID. (,Acidi Formiqut, Fr. j AmtitaniaMrt, Genn.) The acid which
exists in the bodies of ant«, associated with malic acid.
niScialtjr, originally bj Fisher of I^eeds in 1670, and
water, allowing the liquor to cool, sad adding graduBlly 4 parts of the black oiide of
manganese and diniUing. For (he reactions which iakt place see Ute't Chtmical
Dictionary. Its formula is CHG'HO. It is a clear colourless fluid, which crys-
talliwa below 32° into brilliant plates.
FORMUI-iE, CHEMICAL. See Equivalents.
FOBMTLE. The hypothetical base of formic acid.
FOSSIL (foMwiliM, anything dng from the earth). Formerly all minerals were called
fbssils, but the word is now restricted (o eipreaa the remuDg of animal* and plant*
found boried in the earth.
FOSSIL IVORY. The bones and tasks of elephants and mammoths are found in
eanem Siberia, and along the ihorea of the Arctic aea, in great ahnndance. The tusk*
are collected for sale, but it ia much less valnable than the recent ivory.
FOUNDING. In foundries attached to blast-furnaces, where ftvm 20 to 30 tons
of iron are made ptr diem, the moulds are generally mere troughs cut in the sand
into which Ihe melted metal flows and cools in contact with the air. The aarfoces of
the castings made in this manner present appearancel which vary according to the
qnality of the iron.
The kinds of iron adapted for founding purposes are those which are most fluid when
melted, and which contain moat carbon, and are called Noa. 1 and 2. They are dis-
n fork," or an engine to have the
tingnixhedbylbe surface of the pij, . ,
cooling, being smooth, and presenting a slightly c(
" ' ' ' ■ 1, and of the white crystallioi
I figure.
. „ , . . . . .._, - , D - 5t suitable for making into
wrought iron)present a concave figure, and thesur&cea are very irregular and pitied
with holes. The colour of the fracture, and Ihe closeneaa of the gram, alao indicate
the proportion of carbon in pig-iron.
The miitares of metal, melting temperalnres of metal, &c., require Ihr closest
observatioTi on the part of the workmen and foremen who practice iron founding, and
these mechanica are in the practice of observing differences ao miunte that they
cannot be appreciated by the chemist, or expreaaed in words.
Machinery baa enabled the modern fouuder, by means of railways, turn-tables.
282 FOUNDING.
travelling -cranes, and steam-power, to moTe at will the heaviest masses witfaoat con-
fusion and with great expedition ; but nothing but the traditions of the fiictory, and
the constant habit of observation will enable him to conduct properly the melting and
casting of metal so as to arrive at certain results.
This is proved by the constant failures of those who undertake to make descriptions
of castings, of which they have had no previous knowledge.
Each branch of foundry work must be studied in detail, and we can only pretend
to indicate those directions in which progress has been and is being made.
Foundry. — The process of iron smelting and the construction of furnaces having
been described under other heads, the remaining part of the business of a foundry, viz.,
that which relates to the preparation of the moulds and moulding, will now be described.
Moulding. — The art of moulding is one of the most important processes carried on
in a foundry, and the success of the founder is directly proportioned to the skill and in-
genuity brought to bear upon the production of the patterns and the system of moulding.
Before metals can be cast into the variety of shapes in which they are wanted,
patterns must be prepared of wood or metal, and then moulds constructed of some
sufficiently infusible material capable of receiving the fluid metal, and retaining it
without uniting with it until it has solidified.
A mixture of sand and loam (packed tightly into metal boxes, called flasks) is
generally chosen as the material for making moulds, and is employed advantageoosly
for several important reasons.
Flasks. — In modern foundries a system has been invented, by which flasks of any
dimensions may be constructed by means of bolting together a number of rectangular
frames of cast-iron, so arranged as to admit of being easily connected together.
When the particular castings for which the flask has been constructed, or rather
compounded, are completed, the separate pieces are unbolted, and are ready to be
combined in some new form appropriate to the dimensions of the pattern next to be
moulded in them.
The loss of capital, &c., invested in flasks, only occasionally used, is thus saved, as
well as loss of time in searching for the size required. The space devoted, on the old
system, to the reception of flasks belonging to a foundry was very large, and this
may now be appropriated to other purposes.
Sand and loam, — Founders formerly used, on account of price, the description
of sand most accessible to them, but at the present time, the convenience and cheap*
ness of railway carriage has enabled special qualities of sand to be delivered to all
parts of England.
For founding purposes sand is much improved by the admixture of coke, crushed
and reduced to a fine powder, and a mill for this purpose is as necessary in every
large foundry as those for grinding and mixing loam.
Moulding sand must be a mixture of a large quantity of silex and a small quantity
of alumina — the property of the latter material being to cement the grains of silex
together. Loam consists of the same materials mingled in opposite proportions.
The preparation of loam for those purposes for which sand is not adapted, is an
important duty in a foundry, for a great quantity of loam cores have to be made and
dried in proper ovens, which is a tedious operation.
Many castings, such as the screws for steamers, are more conveniently cast in
moulds constructed of wet loam. These are shaped to the required form when the
clay is moist, and then carefully dried afterwards.
Other castings are of such peculiar shapes that they can only be produced in
moulds that take in a vast number of pieces. These moulds are then formed of a
number of pieces of hardened sand, held together by strips of iron or of plaster, if
the sand used is not coherent enough of itself.
Compounds of silex and alumina are very infVisible, and when moistened with water
and faced with carbonaceous matter, they are capable of receiving the most delicate
impressions from the patterns which the founder employs.
Grains of sand are so irregular in shape themselves that they leave innumerable
irregular spaces between them, and these intervals form a net work of channels
which permit the rapid escape of the gases, which are so violently generated by the
contact of hot metal fidling upon wet sand.
Machine Castings. — Every year, engineers order castings to be prepared of more
difficult and complicated forms, and with greater perfection of surfieu^ then they have
required before.
The reason of this is, that with the progress of the mechanical arts larger and
stronger machines are continually being introduced. In these machines greater
steadiness of cast-iron frame work is necessary, than can conveniently be obtained
when the frame is made out of a number of pieces of iron cast separately and then
bolted together. It would be impossible to mould large frames with pieces projecting
on all sides (prepared to receive the moving parts of the machines), and jutting out
FOUNDING. 283
in contrary directions, in any flasks filled with wet sand, for the pattern never coald
be removed without destroying the impression. To meet these difficalties the modem
ironfounder has had to follow those plans which were first proved practicable by
those who have devoted themselves to casting bronze statues. In founding, as in so
many other branches of manufacture, the discoveries made in prosecuting the fine
arts have been advantageously adopted by thoso engaged in works of utility.
FaUe Core*. — The introduction of the drawbacks, or false cores, made of sand
pressed hard (and admitting of taking to pieces by joints, at each of which a layer of
parting sand is prepared), used for figure casting, enables the moulder to work at his
leisure, without fearing that his mould may tumble to pieces, and also enables him to
fiuhion these drawbacks or cores into the most complicated forms, with the power to
remove them while the pattern is removed, and build them up again round the empty
space (fonnerly occupied by the pattern) with the greatest facility and accuracy.
The workmen, whose occupation is to knead the sand into the forms required
by the founder, are termed moulders, and they form a very numerous bcdy of
mechanics, demanding and receiving high wages.
The moulder has often only his sand, his flasks, cranes, and a few simple tools (for
smoothing rough places, and for repairing the places in the sand where the mould
has broken away during the lifting of the pattern) ; he has to make proper arrangements
for the exit of the atmospheric air which leaves the mould as the fluid metal takes
its place ; and he is expected to produce an exact copy in metal iVom any pattern,
simple or complicated, which may be brought before him.
It will be evident that to produce a good result with such imperfect appliances as
the ordinary moulder uses, a skilful workman must be employed, and time expended
in proportion to the difficulty of the operations to be performed.
Where only a few impressions from a model are required, it is not worth while
to spend money in making expensive patterns, or providing those appliances which
may enable patterns to be moulded with facility and little skill ; but where thousands
of castings are wanted of one shape, it is expedient to spend money and skill on
patterns and tools, and reduce the work of the moulder to its minimum.
Management. — The best managed foundry is not that in which good castings are
obtained by the employment of skilled workmen at a great expense, and without
trouble or thought on the part of the principal, but rather that in which the patterns
have been constructed with a special reference to their being cast with the minimum
of skill and the maximum of accuracy. It is only by the forethought and calculation
of the manager that subsequent operations can be r^uced to their smallest cost ; and
in the foundry, as in all other manufactories, the true principles of economy are only
practised where the head work of one person saves the manual labour of a large number.
ImprovemenU. — The attention of founders has been turned — 1st, to the methods
by which the labour of making moulds in sand might be reduced ; 2nd, to the intro-
duction of improvements in the mode of constructing patterns and moulds ; and 3rd,
to the manufiictnre of metallic moulds for those purposes for which they could be
applied. A great progress has been made during the last twenty years in these
different directions.
Machine Moulding. — In the large industry carried on for the production of
cast-iron pipes for the conveyance of water and gas, machinery hgs been applied so
that the operation of pipe-moulding is performed almost without manual labour, with
great rapidity and precision. The cost of pipes at the present time is only about 2/.
per ton above the value of pig-iron, out of which they are made. A sum very small
when it is considered that the iron has to be re-melted, an operation involving both
a cost of fuel and a loss of 5 to 20 percent, of the iron in the cupola. An ingenious
machine for moulding in sand, spur and bevel wheels of any pitch or diameter has
been employed in I^ancashire ; the advantage being that the machine moulding-tool
acts directly upon the sand without the intervention of any pattern or mould. In any
large foundry there is an enormous accumulation of costly wheel-patterns, taking up
a great deal of space, and these can now be dispensed with by substituting the wheel
moulding-machine. Railway chairs are moulded in a machine ; and plough shares,which
although only weighing a few pounds each, are sold at the low rate of 8/. a ton, are
moulded in a machine.
Plate Coating, — Under the next class of improvements the introduction of plate-
casting has been the most fruitful of good results.
One great source of expense and trouble in a foundry is the injury done to patterns
and to Uieir impressions in the sand by the necessity, under the ordinary system of
moulding, of striking the pattern, or pushing it first in one direction and then in
another in order to loosen it Now, the object of the machinist is to construct all
his spindles, bearings, bolts, and wheels, of specified sizes, and then to cast the framing
of his machine so accurately that the working parts may fit into the tnme without
any manual labour. In order to effect this, every projection and every aperture in
284 FOUNDINa
the csfting mmt be at an eiset distance, and this caa onl^ be attaiaed bj emplojiog
Buch a system as that of plate-casliog, nbere the pBlt*m is attached 6rmly to a plUe,
and it is impoisjble for the moulder to distort or injure Ihe impreuioo. PUte-cuting
hel been long known, bat nas practically confined for many yean to the prodnOtMO
of imall Brticles, such as cast nails and rivets.
In a piste-mould for riTet-caeiing, the shafls of the rivets are attached to one aide cl
tbe plate, which is j-in. thick, aad planed on both sides. The heads of the riTCti are
on the opposite side of the plate. The gnidts on the upper and lower fluk admit
the plate to fit between them, and when the plate is withdrawn the upper aitd
lower flaak close perfectly, and are in all reapecia like ordinary moulderm' flasks.
The principle of moulding is Tery simple, sod can be performed without *kill«d
868
A. lud. B B. Awll. It R, rtvM l^Uteni. P, plUh
labour ten limes as fast ai ordioary mouldini;, and with far greater aecimkcy.
Tbe plate is iaserled between tbe upper and lower flasks, and sand is filled in i
tbe pUle is then withdrawn by simply liftiag it; the guides prevent any ahaking
in Ibis operation ; when the flasks are closed the impression of the head of each
riTct a exactly perpendicular to its shaft. The first expense of patterns and
plates of this deseripliou ia large, but the accuracy and rapidity of the process of
mooldiag is so advantageous as to cause us to look (□ the applicatiogs of plate-casting*
becoming Tery exteosive, since tbe requiremeuts of tbe mac bine -maker demand eiery
year better castings at lower prices.
When both sidrs of a pattern arc symmetrical one half only need be attached to
the smooth plate, the other face of the plate being left blank, An impresuon of the
pattern muet be taken oCT both in tbe upper and lower flask, and when these are united
the result will be the same as if both sides of the plate had been moulded teom. For
nnsymmetrical patterns both sides of the plate must be employed. The system of
nsing plates with apertures in them, through which patterns could be pushed and
withdrawn by mcattf of a levtr, was first employed in casting brass nails. A modiB-
catiou of this systt;m has been eitensively employed at Woolwich for moulding shot
and ahells, in the following manner: —
Shill Cmtiag. — A circular aperture is made in a horiiontal planed plate of iroo.
two inches thick. Through this a sphere of iron, of the same diameter as the aper-
ture, is pushed until exactly a hemisphere appears above the plate. The lower flask
is put OD to the plate, and sand filled in ; tbe lever being reheved the sphere falls by its
own weight i the lower flask is removed and the upper flask put on the plate ; tbe sphere
is pushed through the plate as before, sand filled in, with great rapidity and accuracy.
The sand cores for filling up that part of the shell which is to be hollow are alao
carefully and quickly made at Woolwich. Tbe halves of the core-mould, open and
shut with a lever, so that Che bad plan of striking the core-mould is avoided as com-
pletely as the bad plan of striking the pattern is iu^e process ofmonlding shot and shell.
Thtorg of Catting. — Berore leaving tbe subject of the use of sand moulds, we may
remark that iron and brass castings with a perfect surface can only be produced when
the mould is well dried and heated, so as to drive oat any moisture from tbe aperture*
between the grains of sand. By this means channels are opened for the rapid escape
of the heated air and gas expelled by tbe entrance of the fluid metal into tbe mould,
tmd the surface of the melal is not cooled by its contact with damp or cold sand.
It is also well to mix charcoal dust, or coke dust, with the sand ; and for fine castings
to cover the sur&ce of the sand with a coating of charcoal dust The object of this
proceeding is to reduce tbe oxide which may be present in the metal. This opeivtian
of reducing tbe oxide of a metal iustantaneously is performed with tbe greatest cer-
tainty by this simple means, invented, probaUy, by die earliest metaUargistB. By
FOUNDING. 285
incorporatuig a quantity of charcoal or coke-dust with the sand, or facing the sand
with carhonaceons matter, any oxide of the metal which may be floating amongst
the pore metal is at once reduced. Sand (being a non-conductor) does not ab-
stract the heat from the fluid metal rapidly, and, therefore, solidification of the
metal takes place comparatively regularly and equally throughout the mass ; when
one part of the casting solidifies before the adjoining part, flaws often occur, and to
aToid these the skill of the practical founder is necessary in arranging for the entrance
of the metal at the proper point, and for the exit of the air.
We next proceed to the third class of improvements in moulding, that of the exten-
sion of the application of metallic moulds.
MettU Moutda, — The practice of casting bronze weapons in moulds made of bronze
(blackened over on their surface to prevent the fluid metal uniting with the mould)
appears to have been a very general one among the ancients.
Some moulds of this description have been discovered amongst the Celtic (?)
remains disinterred in different parts of Europe.
The facility for the escape of the heated air and gases fh>m the sand moulds into
which liquid metal is poured, is so much greater than that from moulds of metal, that
at the present time neither brass nor iron is poured into metallic moulds, except when
a particular purpose is to be attained* viz., that of chilling the surface of the iron and
making it as hard as steeL Iron cannot be chilled or hardened in a sand mould.
Chilled Iron. — This process of casting in metal moulds was once supposed to be a
modem invention ; but it now appears, fh»m the metal moulds discovered among the
remains of the Celtic race throughout Europe, that the bronze weapons of the people
who preceded the Romans were generally cast in metallic moulds, and not in sand.
Chilled castings have been brought to great perfection by Messrs. Ransome, of Ipswich.
Their chilled ploughshares and chilled railway chairs are cast in moulds of such a con-
struction that the melted iron comes in contact with iron in those parts of the moulds,
where it is wanted to be chilled. A section of the casting shows the effect of chilling.
Zmc, — In casting zinc (a cheap and abundant metal), which fuses at a low tempera-
ture, metallic moulds may be most advantageously used. It is, however, necessary to
heat the iron or brass mould nearly to the temperature of melting zinc, in order that the
rapid abstraction of heat from the fluid metal may be preyented. The preparaiion of
metal moulds, and the casting soft metal in them is now an extensive and important
industry on the Continent, for ornamental zinc castings have suddenly come into ex-
tensive use in consequence of the discovery of the electrotyping process. When covered
with a thin coating of brass or copper by a galvanic battery, zinc may be bronzed so
as to present almost the exact external appearances of real bronze at a tenth of the cost.
When metal moulds are used their first cost is very great, as they must be made in
numerous separate pieces so as to liberate the castings. The joints and ornaments
have to be chased and accurately fitted at a great expense. Their use, however, re-
quires no skill in the workman, and the rapidity with which the zinc is cast, the mould
taken to pieces, and the casting removed, renders the operation a very rapid aud econo-
mical one. — A. T.
Such is a general view of the practice of founding. The details, however, which
are contained in the original article in the last edition of this dictionary, appear so
valuable that that article is retained in addition to the above.
The essential parts of a well-mounted iron foundry, are,
1. Magazines for pig irons of different qualities, which are 'to be mixed in certain
proportions, for producing castings of peculiar qualities ; as also for coal, coke, sands,
clay, powdered charcoal, and cow-hair for giving tenacity to the loam mouldings.
2. One or more coke ovens.
3. A workshop for preparing the patterns and materials of the moulds. It should
contain small edge millstones for grinding and mixing tlie loam, and another mill
for grinding coal and charcoal.
4. A vast area, called properly the foundry, in which the moulds are made and filled
with the melted metal. These moulds are m general very heavy, consisting of two
parts at least, which must be separated, turned upside down several times, and replaced
very exactly upon one another. The casting is generally effected by means of large
ladles or pots, in which the melted iron is transported from the cupola where it is
fused. Hence the foundry ought to be provided with cranes, having jibs movable in
every direction.
5. A stove in which such moulds may be readily introduced, as require to be
entirely deprived of humidity, and where a strong heat may be uniformly maintained.
6. Both blast and air furnaces, capable of melting speedily the quantity of cast-iron
to be employed each day.
7. A blowing machine to urge the fusion in the furnaces.
Fig, 869, represents the general plan of a well-mounted foundry.
286 FOUNDING.
a, is a CDpola farnace ; it is capable of containing 5 tons of cast-iron.
a', is a similar furnace, but of smaller dimensions, for bringing down 1] tons.
a"y is a farnace like the first, in reserve for great castings.
hhhh^K vast foimdry apartment, whose floor to a yard in depth, is formed of
sand and charcoal powder, which have already been used for castings, and are ready
for heaping np into a substratum, or to be scooped out when depth is wanted for the
moulds. There are besides several cylindrical pits, from five to seven yards in depth,
placed near the furnaces. They are lined with brick work, and are usually left iuli
of moulding sand. They are emptied in order to receive large moulds, care being
had that their top is always below the orifice from which the melted metal is tapped.
These moulds, and the ladles full of melted metal are lifted and transported by
the arm of one or more men, when their weight is moderate ; but if it be considerable,
S69 they are moved about by cranes, whose vertical
shafts are placed at c, cf, e, in correspondence, so
that they may upon occasion transfer the load
from one to another. Each crane is composed
principally of an upright shaft, embraced at top
by a collet, and turning below upon a pivot in
a step ; next of a horizontal beam, stretched oat
from nearly the top of the former, with an
oblique stay running downwards, like that of a
gallows. The horizontal beam supports a
movable carriage, to which the tackle is sns-
pended for raising the weights. This carriage
is made to glide backwards or forwards along
the beam by means of a simple rack and pinion
mechanism, whose long handle descends within
reach of the workman's hand.
By these arrangements in the play of the three cranes, masses weighing five tons
may be transported and laid down with the greatest precision upon any point whatever
in the interior of the three circles traced upon ^|^. 869, with the points c, c/, e, as centres,
c, <f, «; are the steps, upon which the upright shafts of the three cranes rest and
turn. Each shaft is 16 feet high.
//, is the drying stove, having its floor upon a level with that of the foundry.
f f\ is a supplementary stove for small articles.
9 9 ^t are the coking ovens.
h is the blowing machine or fan.
1. is the steam-engine, for driving the fan, the loam-edge stones,
A, and the charcoal mill.
f , are the boiler and the ftimace of the engine.
Uy workshop for preparing the loam and other materials of moulding.
/, is the apartment for the patterns.
The pig-iron, coals, &c., are placed either imder sheds or in the open air, round the
above buildings ; where are also a smith's forge, a carpenter's shop, and an apartment
mounted with vices for chipping and rough cleaning the castings by chisels and files.
Sach a .foundry may be erected upon a square surface of about 80 yards on each side,
and will be capable, by casting in the afternoon and evening of each day, partly in
large and partly in small pieces, of turning out ft-om 700 to 800 tons per annum, with
an establishment of 100 operatives, including some moulding boys.
Of making the Moulds. — 1. Each mould ought to present the exact form of its object.
2. It should have such solidity that the melted metal may be poured into it, and fill
it entirely without altering its shape in any point.
3. The air which occupies the vacant spaces in it, as well as the carburetted gases
generated by the heat, must have a ready vent ; for if they are but partially confined,
they expand by the heat, and may crack, even blow up the moulds, or at any rate
become dispersed through the metal, making it vesicular and unsound.
There are three distinct methods of making the moulds : —
1. In green sand; 2. In baked sand; 3. In loam.
To enumerate the different means employed to make every sort of mould exceeds
the limits prescribed to this work. We shall merely indicate for each species of
moulding, what is common to all the operations ; and then describe the fabrication
of a few such moulds as appear most proper to g^ve general views of this peculiar art
Moulding in green sand, — The name green is given to a mixture of the sand as it
comes from its native bed, with about one twelfth its bulk of coal reduced to powder,
and damped in such a manner as to form a porous compound, capable of preserving
the forms of the objects impressed upon it This sand ought to be slightly argillaceous,
with particles not exceeding a pin's head in size. When this mixture has once served
FOUNDING. 287
for a mould, and been filled with metal, it cannot be emplojed again except for the
coarsest castings, and is generally used for filling up the bottoms of fVesh moulds.
For moulding any piece in gfreen sand, an exact pattern of the object must be pre-
pared in wood or metal; the latter being preferable, as not liable to warping,
swelling, or shrinkage.
A couple of iron frames form a case or box, which serves as an envelope to the
mould. Such boxes constitute an essential and very expensive part of the furniture
of a foundry. It is a rectangular frame, without bottom or lid, whose two largest
sides are united by a series of cross bars, parallel to each other, and placed from 6 to
8 inches apart.
The two halves of the box carry ears corresponding exactly with one another ; of
which one set is pierced with holes, but the other has points which enter truly into
these holes, and may be made fast in them by cross pins or wedges, so that the pair
becomes one solid body. Within this frame there is abundance of room for containing
the pattern of the piece to be moulded with its encasing sand, which being rammed into
the frame, is retained by friction against the lateral faces and cross bars of the mould.
When a mould is to be formed, a box of suitable dimensions is taken asimder, and
each half. No. 1 and No. 2, is laid upon the floor of the foundry. Oreen sand is
thrown with a shovel into No. I so as to fill it ; when it is gently pressed in with a
rammer. The object of this operation is to form a plane surface upon which to lay in
the pattern with a slight degree of pressure, varying with its shape. No. 1 being
covered with sand, the frame No. 2 is laid upon it, so as to form the box. No. 2
being now filled carefully with the green sand, the box is inverted, so as to place
No. 1 uppermost, which is then detached and lifted off in a truly vertical position ;
carrying with it the body of sand formed at the commencement of the operation. The
pattern remains imbedded in the sand of No. 2, which has been exactly moulded upon
a great portion of its surfiuse. The moulder condenses the sand in the parts nearest
to the pattern, by sprinkling a little water upon it, and trimming the ill-shaped parts
with small iron trowels of different kinds. He then dusts a liule well-dried finely-
sifted sand over all the visible sur&ce of the pattern, and of the sand surrounding it $
this is done to prevent adhesion when he replaces the firame No. 1.
He next destroys the preparatory smooth bed or area formed in this frame, covers
the pattern with green sand, replaces the frame 1 upon 2 to reproduce the box, and
proceeds to fill and ram Na 1, as he had previously done No. 2. The object of this
operation is to obtain very exactly a concavity in the fnme No. 1, having the shape
of the part of the model impressed coarsely upon the surface formed at the beginning,
and which was meant merely to support the pattern and the sand sprinkled over it,
till it got imbedded in No. 2.
The two frames in their last position, along with their sand, may be compared to a box
of which No.l is the lid, and whose interioris adjusted exactly upon the enclosed pattern.
If we open this box, and after taking out Uie pattern, close its two halves again,
then pour in melted metal till it fill every void space, and become solid, we shall
obviously attain the wished-for end, and produce a piece of cast iron similar to the
pattern. But many precautions must still be taken before we can hit this point We
must first lead through the mass of sand in the frame No. 1, one or more channels for
the introduction of the melted metal ; and though one may suffice for this purpose,
another must be made for letting the air escape. The metal is run in by several
orifices at once, when the piece has considerable surface, but little thickness, so that
it may reach the remotest points sufficiently hot and liquid.
The parts of the mould near the pattern must likewise be pierced with small holes,
by means of wires traversing the whole body of the sand, in order to render the mould
more porous, and to facilitate the escape of the air and the gases. Then, before lifting
«off the frame No. I, we must tap the pattern slightly, otherwise the sand enclosing it
would stick to it in several points, and the operation would not succeed. These gentle
jolts are given by means of one or more pieces of iron wire which have been screwed
vertically into the pattern before finally ramming the sand into the frame No. 1, o^
which enter merely into holes in the pattern. These pieces are sufficiently long to
pass out through Uie sand when the box is filled ; and it is upon their upper ends that
the horizontal blows of the hammer are given ; their force being regulated by the
weight and magnitude of the pattern. These rods are then removed by drawing them
straight out ; after which the fVame No. 1 may be lifted off smoothly from the pattern.
The pattern itself is taken out, by lifting it in all its parts at once, by means of
screw pins ad^justed at the moment This manoeuvre is executed, for large pieces,
almost always by several men, who while they lift the pattern with one hand, strike
it with the other with small repeated blows to detach the sand entirely, in which it is
generally more engaged than it was in that of the frame No. 1. But in spite of all
these precautions, there are always some degradations in one or.other of the two parts
283 FOUNDING.
of the mould ; which are immediately repaired by the workman with damp aand,
which he applies and presses gently with his trowel, so as to restore the izgured forms.
Hitherto it has been supposed that all the sand rammed into the box is of one
kind; but from economy, the green sand is used only to form the portion of the mould
next the pattern, in a stratum of about an inch thick ; the rest of the surrounding space
is filled with the sand of the floor which has been used in former castings. The interior
layer round the pattern is called in this case, new sand.
It may happen that the pattern is too complex to be taken out without damaging the
mould, by two frames alone ; then three or more are mutually adjusted to form the box.
When the mould, taken asunder into two or more parts, has been properly repaired,
its interior surface must be dusted over with wood charcoal reduced to a Yery fine
powder, and tied up in a small linen bag, which is shaken by hand. The charcoal is
thus sifted at the moment of application, and sticks to the whole surface which has
been previously damped a little. It is afterwards polished with a fine troweL Some-
times, in order to avoid using too much charcoal, the surfaces are finally dusted otct
with sand, very finely pulverised, from a bag like the charcoaL The two frames are
now replaced with great exactness, made fast together by the ears, with wedged bolts
laid truly level, or at the requisite slope, and loaded with considerable weights. When
the casting is large, the charcoal dusting, as well as that of fine sand, is suppressed.
Every thing is now ready for the introduction of the fused metal.
Moulding in baked or used sand — The mechanical part of this process is the same as
that of the preceding. But when the castings are large, and especially if they are tall,
hydrostatic pfessure of the melted metal upon the sides of the mould cannot be counter*
acted by the force of cohesion which the sand acquires by ramming. We most in
that case adapt to each of these frames a solid side, pierced with numerous small holes
to give issue to the gases. This does not form one body with the rest of the frame,
but is attached extemporaneously to it by bars and wedged bolts. In general no
ground coal is mixed with this sand. Whenever the mould is finished, it is trans-
ferred to the drying stove, where it may remain from twelve to twenty-four boors at
most, till it be deprived of all its humidity. The sand is then said to be baked, or
annealed. The experienced moulder knows how to mix the different sands placed at
his disposal, so that the mass of the mould as it comes out of the stove, may preserve
its form, and be sufficiently porous. Such moulds allow the gases to pass through
them much more readily than those made of green sand; and in general the castings
they turn out are less vesicular, and smoother upon the surface. Semetimes in a large
piece, the three kinds of moulding, that in green sand, in baked sand, and in loam,
are combined to produce the best result.
Moulding in loam. — This kind of work is executed from drawings of the pieces to
be moulded, without being at the expense of making patterns. The mould is formed
of a pasty mixture of clay, water, sand, and cow's hair, or other cheap filamentous
matter, kneaded toother in what is called the loam mill. The proportions of the
ingredients are varied to suit the nature of the casting. When the paste requires to
be made very light, horse dung or chopped straw is added to it.
We shall illustrate the mode of fabricating loam moulds, by a simple case, such as that
of a sugar pan. Fig. 870 is the pan. There is laid upon the floor of the foundry, an
870 871 872
annular platform of cast-iron, a, h^fig. 871 ; and upon its centre c, rests the lower extre-
mity of a vertical shaft, adjusted so as to turn freely upon itself, while it makes a
wooden pattern ef^Jig. 872, describe a surface of revolution identical with the internal
surface reversed of the boiler intended to be made. The outline e g^ of the pattern is
fashioned so as to describe the surface of the edge of the vessel Upon the part a, </, b, d,
fig. 872, of the flat cast-iron rin«, there must next be constructed, with bricks laid
either flat or on their edge, and clay, a kind of dome, h ik,fig. 872, from two to four
inches thick, according to the size and weight of the piece to be moulded. The ex-
ternal surface of the brick dome ought to be everywhere two inches distant at least,
from the surface described by the arc «,/. Before building up the dome to the point
i, coals are to be placed in its inside upon the floor, which may be afterwards kindled
for drying the mould. The top is then formed, leaving at t, round the upright shaft
FOUNDING. 289
of rerolntion, only ft yeiy imall outlet This ftpertnre, m alto lome others left under
the edges of the iron ring, enable the moulder to light the fire when it becomes neces-
sary, and to graduate it so as to make it last long enough without needing more fuel,
till the mould be quite finished and dry. The combustion should be always extremely
slow.
Orer the brick dome a jMSty layer of loam is applied, and rounded with the mould
jf, e,/; this surface is then coated with a much smoother loam, by means of the concaye
edge of the nine mould. Upon the latter sur&ce, the inside of the sugar pan is cast;
the line eg having traced, in its rcTolutioo, a ledge, si. The fire is now kindled, and
as the surftce of the mould becomes dry, it is painted orer by a brush with a mixture
of water, charcoal powder, and a little clay, in order to prevent adhesion between the
suriace already dried and the coats of clay about to be applied to it The board a ef
is now removed, and replaced by another, i/fff,fi9' 874, whose edge eff* describes
the oater surface of the pan. Over the surface e,/, a layer of loam is applied, which
is turned and polished so as to produce the surface of revolution <7*, as was done for
the surface e/; only in the latter case, the line ef ^ of the board does not form a new
shoulder, but rubs hghtly against wu
The layer of loam includei between the two snrfhces «/) e'/', is an exact represen-
tation of the sugar pan. When this larer is well dried by the heat of the interior fire,
it most be painted like the former. The upright shaft is now removed, leaving the
small vent hole through which it passed to promote the complete combustion of the coal
There must be now laid horixontally upon the ears of Uie platform d d,Jig, 871, ano*
873 874
ther annular platform pq^ike the former, but a little larger, and without anycross-bar.
The relative position of these two platforms is shown in fig. 875. Upon the surfkce
ef f',fig' 874, a new layer of loam is laid, two inches thick, of which the surface is
smoothed by hand. Then upon the pUtform p 9, fig, 87 5, a brick vault is constructed,
whose inner surface is applied to the layer of loam. This contracts a strong adherence
with the bricks which absorb a part of its moisture, while the coat of paint spread over
the surface el f^ prevents it fh>m sticking to the preceding layers of loam. The brick
dome ought to be built solidly.
The whole mass is now to be thoroughly dried by the continuance of the fire, the
draught of which is supported by a small vent left in the upper part of the new dome;
and when all is properly dry, the two iron pUtforms are adjusted to each other by pin
points, and pq\A lifted off, taking care to keep it in ahorixontal position. Upon this
platform are removed the last brick dome, and the layer of loam which had been applied
next to it ; the latter of which represents exactly by its inside the mould of the surface
ef f*, that is, of the oatside of the pan. The crust contained between t f and ef f is
broken away, an operation easily done without injury to the surface tf /, which repre-
sents exactly the inner surfiM^e of the pan ; or only to the shoulder m, corresponding to
the edge of the vessel. The top aperture through which the upright shaft passed must
be now closed ; only the one is kept open in the portion of the mould lifted off upon
p q ; b«rcattse through this opening the melted metal is to be poured in the process of
casting. The two pUtforms being replaced above each other very exactly, by means
of the adjusting pin- points, the mould is completely formed, and ready for the reception
of the metal.
When the olject to be moulded presents more complicated forms than the one now
chosen for the sake of illustration, it is always by analogous processes that the workman
constructs his loam moulds, but his sagacity must hit upon modes of executing many
things which at first sight appear to be scarcely possible. Thus, when the forms of the
interior and exterior do not permit the mould to be separated in two pieces, it is divided
into several, which are nicely fitted with adjusting pins. More than two cast-iron
rings or platforms are sometimes necessary. When ovals or angular surfaces mast be
traced instead of those of revolution, no upright shaft is used, but wooden or cast-iron
guides made on purpose, along which the pattern cut-out board is slid according to the
drawing of the piece. Iron wires and claws are often interspersed through the brick
Vol. IL U
290
FOUNDING.
work to give it cobesion. The eore, kernel, or inner mould of a koUow catting it ft«-
4)aentl7 fitted in when the outer thell it moiUded. The cate of a gat-light retort, fig,
876, will illustrate this matter. The core of the retort ought to have tJ& form < e e e;
and he very tolid, since it cannot be fixed in the outer mould for the catting, except in
the part suinding out of the retort towardt m m. It mutt be modelled in loam, opoa
a piece of catt-iron called a /anient, made ezpreasly for thit pnrpote. The luitem is a
cylinder or a truncated hollow cone of catt iron, about half an inch thick ; aiid differ-
ently thaped for every different core. The tnrihce it perforated with holet of about
half an inch in diameter. It is mounted by meant of iron crottbart, upon an iron axit,
876
which travertes it in the direction of iu length. Fig, 877 repretentt a horixontal
section through the axis of the core; j^ A it the axit of the lantern, figured itself at t il
ki\ o 1 1 o is a kiad of disc or dish, perpendicular to the axit, open at i i, forming one
piece with the lantern, whose circumference o o presents a curve aimilar to the section
of the core, made at right angles to its axis. We shall see presently the two uses for
which this dish it intended. The axis ^r A it laid upon two gudgeons, and handlet are
placed at each of its extremities, to facilitate the operation in making the core. Upon
the whole surface of the lantern, from the point A to the collet formed by the dish, a
hay cord as thick as the finger is wound. Even two or more coila may be applied, at
occasion requires, over which loam is spread to the exact form of the core, by applying
with the hii^nd a board, against the dish o o, with its edge cut out to the desired shape ;
• as also against another dish, adjusted at the time towards A; while by meant of the
handles a rotatory movement it given to the whole apparatut.
The hay interposed between the lantern and the loam, which represents the crust of
the core, aids the adheaion of the clay with the catt iron of the lantern, and givet passage
to the holet in itt surface, for the air to escape through in the casting.
When the core it flnithed, and hat been put into tibe drying ttove, the axit ^ A it
taken out, then the tmall opening which it leavet at the point A, it plugged with clay.
Thit is done by supporting the core by the edget of the dith, in a vertical position. It
is now ready to be introduced into the hollow mould of the piece.
This mould executed in baked sand contittt jof three pieces, two of which, absolutely
similar, are represented, yS^. 878, at p 9, the third it thown at r a. The two similar
paru p 9, present each the longitudinal half of the
nearly cylindrical portion of the outer surface of the
gas retort; to that when they are brought together,
the cylinder it formed ; r a containt in itt cavity the
kind of hemisphere which formt the bottom of the
retort. Hence, by adding this part of the mould to
the end of the two others, the retulting apparatut pre-
sents, in its interior, the exact mould of the outside of
the retort ; an empty cylindrical portion I <, whose
axis is the same as that of the cylinder u ic, and whoie
surface, if prolonged, would be every where distant
from the surface u u, by a quantity equal to the desired .^,
thickness of the retort The diameter of the cylinder \ _
tt'w precisely equal to that of the core, which is jr-rr — T?^^ Ir-w^sc — -rr^
slightly conical, in order that it may enter easily into ( o|i2S!Sl7 ^ ^t^^J
this aperture 1 1, and close it very exactly when it it ' """^
introduced to the collet or neck.
The three parta of the mould and the core being prepared, the two pieces p q, must
first be united, and supported in an upright position ; then the core must be let down
into the opening 1 1, Jig 879. When the plate or disc o o of the core is supported upon
the mould, we must see that the end of the core is everywhere equally distant from
the edge of the external sur&ce m u, and that it does not go too fhr beyond the line q 9.
Should there he an inaccuracy, we mutt correct it by tlender iron tlipt pkced under
878
879
FOUNDING.
291
tbe edge of the disc oo; then by means of a east ifon eross, and screw bolts 9 p, we fix
the eore immoTably. The whole apparatus is now set down upon r a, and we fix with
screw bolts the plane sarfhce q q upon r r ; then introdooe the melted metal hj an
aperture 2, which has been left at the npper part of the mould.
When, instead of the example now selected, the core of the piece to be cast most go
beyond the moald of the external surfiMe, as is the case with a pipe open at each end,
the thing m man simple, because we may essily adjust and fix the core by its two'
ends.
In casting a retort, the metal is poored into the mould set upright. It is important
to maintain this position in the two last examples of casting ; for all the foreign matters
which may soil the metal during its flow, as the sand, the charcoal, gases, scoric, being
less dense than it, rise constantly to the surface. The hydrostatic pressure produced
by a high gate, or filling- in aperture, contributes much to secure the soundness and
solidity of the casting. This gate piece being supcTfluous, is knocked off almost im-
mediately after, or even before the casting cools. Very long, and somewhat slender
pieces, are usually cast in moulds set up obliquely to the horison. As the metal shrinks
in cooling, the mould should always be somewhat larger than the object intended to
be cast The iron founder reckons in general upon a linear shrinkage of a ninety-
sixth part ; that is one-eighth of an inch per foot
Meltmg o/tke cast- iron, — The metal is usually melted in a cupola ftimace, of which
the d^r^""*^* are yery Tarioas. Fig, 880 represents in plan, section* and elevation,
880
one of these fomaces of the largest size; being capable of founding 6 tons of cast-iron
at a time. It is kindled by kying a few chips of wood upon iU bottom, leaying the
orifice e open, and it is then filled up to the throat with coke. The fire is lit at c, and
in a quarter or half an hour, when die body of fiiel is sufficiently kindled, the tuyere
blast is set in action. The flame issues then by the mouth as well as the orifice c,
which has been left open on purpose to consolidate it by the beat Without this pre-
caution, the sides, which are made up in argillaceous sand after each day's work, would
not present the necessary resistance. A quarter of an hour afterwards, the orifice c is
closed with a lump of moist cUy, and sometimes, when the furnace is to contain a
peat body of melted metal, the clay is supported by means of a small plate of cast-
iron fixed against the furnace. Before the blowing machine is set agoing, the open-
ings ggg huL been kept shut Those of them wanted for the tnylres are opened in
u 2
292 FOUNDING.
saccession, beginning at the lowest, the tuyeres being raised according as the level of
the fused iron stands higher in the furnace. The same capola may receive at a time
from one to six tay^res, through which the wind is propelled by the centrifugal action
of an excentric fan or ventilator. It does not appear to be ascertained wbeUier there
be any advantage in placing more than two tuyeres facing each other upon opposite
sides of the furnace. Their diameter at the nozzle varies from 3 to 5 inches. Thej
*are either cylindrical or slightly conical A few minutes after the tuyeres have begun
to blow, when the coke sinks in the furnace, alternate charges of coke and pig iron
must be thrown in. The metal begins to melt in about 20 minutes after its intro-
duction ; and successive charges are then made every 10 minutes nearly ; each charge
containing from 3 cwt. to 5 cwt of iron, and a quantity proportional to the estimnie
given below. The amount of the charges varies of course with the size of the furnace,
and the speed required for the operation. The pigs must be previously broken into
pieces weighing at most 14 or 16 pounds. The vanes of the blowing fan make from
625 to 650 turns per minute. The two cupolas represented fig, 8S1, and anoiher
alongside in the plan, may easily melt 6^ tons of metal in 2} hours ; that Is 2^ tons
per hour. This result is three or four times greater than what was formerly obtained
in similar cupolas, when the blast was thrown in from small nozzles with cylinder
bellows, moved by a steam engine of 10 horses power.
In the course of a year, a considerable foundry like that represented in the plan,
fig. 869, will consume about 300 tons of coke in mehing 1240 tons of cast iron ; con-
sisting of 940 tons of pigs, of different qualities, and 300 tons of broken castings, gate-
pieces, &c. Thus it appears that 48 pounds of coke are consumed for melting every
2 cwt. of metal.
Somewhat less coke is consumed when the fusion is pushed more rapidly, to collect
a great body of melted metal for casting heavy articles ; and more is consumed when,
as in making many small castings, the progress of the founding has to be slackened
from time to time ; otherwise, the metal would remain too long in a state of fusion,
and probably become too cold to afford sharp impressions of the moulds.
It sometimes happens that in the same day, with the same furnace, pieces are to be
cast containing several proportions of different kinds of iron ; in which case, to prevent
an intermixture with the preceding or following charges, a considerable bed of coke
is interposed. Though there be thus a little waste of fuel, it is compensated by the
improved adaptation of the castings to their specific objects. The founding generally
begins at about 3 o'clock, p.m., and goes on till 6 or 8 o'clock. One founder aided by
four labourers for charging. &c., can manage two furnaces.
The following is the work of a well-managed foundry in Derby.
200 lbs. of coke are requisite to melt, or bring down (in the language of the founder),
1 ton of cast iron, after the cupola has been brought to its proper heat, by the com-
bustion in it of 9 baskets of coke, weighing, by my trials, 40 pounds each, » 360 lbs.
The chief talent of the founder consists in discovering the most economical mix-
tures and so compounding them as to produce the desired properties in the castings.
One piece, for example, may be required to have great strength and tenacity to bear
heavy weights or strains ; another must yield readily to the chisel or the file ; a
third must resist sudden alternations of temperature ; and a fourth must be pretty
hard.
The filling in of the melted metal is managed in two ways. For strong pieces, whose
moulds can be buried in the ground at 7 or 8 yards distance from the furnace, the
metal may be run in gutters, formed in the sand of the floor, sustained by plates or
stones. The clay plug is pierced with an iron rod, when ail is ready.
When from the smaller size, or greater distance of the moulds, the melted metal
cannot be run along the floor from the furnace, it is received in cast-iron pots or ladles,
lined with a coat of loam. These are either carried by the hands of two or more men,
or transported by the crane. Between the successive castings, the discharge hole of
the furnace is closed with a lump of clay, applied by means of a stick, having a small
disc of iron fixed at its end.
After the metal is somewhat cooled, the moulds are taken asunder, and the excres-
cences upon the edges of the castings are broken off with a hammer. They are after-
wards niore carefully trimmed or chipped by a chisel when quite cold. The loss of
weight in founding is about 6 J per cent upon the pig iron employed. Each casting
always requires the melting of considerably more than its own weight of iron. This
excess forms the gates, false seams, &c.; the whole of which being deducted, shows
that 1 cwt of coke is consumed for every 3 cwt of iron pot into the furnace ;
for every 138 cwt of crude metal, there will be 100 cwt of castings, 32 of refuse
pieces, and 6 of waste.
Fig, 880, Cupola furnace^ requires a little further description. It is 3 feet wide
within, and 13^ feet high, m m, solid body of masonry, as a basis to the furnace.
FOUNDING. 293
h t, octagonU platform of call iron, vilh ■ ledge id which ihe pUtM a a a a sra
eogsged.
a a, eigbt plates of cast iron, 1 incb thick, absolalely BimilBf ; Only one of Ihem ia
notched at ita lower part in c, to allow the nelled melal to run out, and two of the
otbera have aiz aperturea, g g g. Sen. to admit the luy^rea.
c, orifice fur letting the metal flow oaL A kind of cait iron gutter, t, lined with
loam, is fitted to the orifice.
d, hoops of hammered in):i,4| inches hroadi one half of an inch thick for the boltom
onesi and a quarter of an inch for the npper ones. The intermediate hoopg decrease
in thickness from below upwardi betweeo these limits.
e, cast iron pitter or spout, lined with loam, for mnning off the metal.
f /, cylindrical piece of cast iron, for increaiing the height and draught of Ihe
o, side openings for re-
ceiiing the tujSrea, of which
there are six npon each side
of the fhrnace. Each of them
may b« shut at pleasure, by
means of a small caat iron
pUie. i, made to slide bori-
sonlaJlj in grooTes sunk in
the main plaiei pierced with
the holes g g.
k k, interiM lioing of the
anrface, made of sand, some-
what argillaceous, in the fol-
lowJDgway. After having lud
at ifae bottom of ihe fbmace a
bed ofsand a few inches thick,
sligbilj sloped towards the
orifice of discharge, there is
set upright, in the axis of the
cupota, a wooden cylinder of
its whole height, and of a
diameter a little less than that
of the racant space belonging
to the top of the fumace.
Sand is to be then rammed in
so ■■ to EU Ihe whole of the
farnace; after which the
woodeu cylinder is withdrawn,
and [he lining of the sand is
cat or ihaTcd away, till it has
received the proper form.
This lining lasts generally
5 or 6 weeks, when there aie
■iz meltings weekly.
1 1, cost iron circnlaT plate,
through which the month of
the furnace pasaea for pn>-
tectiog the lining in k dar-
ing the introduelion of the
K H, level of the floor of
the foiiDdry. The portion of
it below the ninning out ori- ■
flee coosiata of sand, so that
it may be readily sunk when
it is wished to receive the
melted metal in ladles or pots
of large dimensions. ' ~~
The fiiD distributes the blast fVom the main pipe^to three principal points, by three
branch tubes of distribution. A register, consining of a cast iron plate sliding with
ftietion in a inmt, aerrea to intercept the blast at any moment, when it is not de'-irablo
to stop the moving power. A large main pipe of line or sheet iron is fitted to the
oriGce of the slide vidve. It is square at the beginuing, or only rounded at the
ADgles; but at a little distance it becomes cylindrical, and conducts the blast to the
03
294 POUNDING.
diyaricating points. There, efteh of the branches tarns up Terticallj, tnd ferminites
at 6 6, Jig. 881, vhere it presents a circular orifice of 7| inches. Upon each of the
upright pipes &, the one end of an elbow-tube of zinc c c c e, fig. 881, is adjusted
rather looselj, and the other end receiyes a tuydre of wrought iron d d, through the
intervention of a shifting hose or collar of leather c e d^ hooped with iron wire to
both the tube and the tuyere. The portion cece may be raised or lowered, by sliding
upon the pipe b, in order to bring the nozzle of the tuydre dd, io the requisite
point of the furnace. The portion cece may be made also of wrought iron. A
power of 4 horses is adequate to drive this fan, for supplying blast to 3 furnaces.
The founders have observed that the efflux of air was not the same when blown into
the atmosphere, as it was when blown into the fhmaces ; the velocity of the fan,
with the same impulsive power, being considerably increased in the latter case.
They imagine that this circumstance arises from the blast being sucked in, so to
speak, by the draught of the furnace, and that the fan then supplied a greater quantity
of air.
The following experimental researches show the fidlacy of this opinion. Two water
siphons, e e e,fff, made of glass tubes, one-fifth of an inch in the bore, were in-
serted into the tuy4re, containing water in the portions ^ g gthhh. The one of these
manometert for measuring the pressure of the air was mserted at A, the other in the
centre of the nozzle. The size of this glass tube was too small to obstruct in anj
sensible degree the outlet of the air. It was found that when the tuyeres of the fan
discharffed into the open air, the expenditure by a nozzle of a constant diameter was
proportional to the number of the revolutions of the vanes. It was further found,
that when the speed of the vanes was constant, the expenditure by one or two nozzles
was proportional to the total area of these nozzles. The fbllowing formulss give the
volume of air furnished by the fan, when the number of turns and the area of the
nozzles are known.
V«l.B.e - »'•»' ^ ° (1)
1-000,000
Volume - """'"'^ S ° (»)
1,000,000
The Tolnme is measured at 82^ Fahr., under a pressure of 29 '6 inches barom.
8 * is the total area of the orifices of the tuyeres in square inches.
n «■ the number of turns of the vanes in a minute.
After measuring the speed of the vanes blowing into the atmosphere, if we intro-
duce the nozzle of discharge into the orifice of the furnace, we shall find that their
speed immediately augments in a notable degree. We might, therefore, naturally
suppose that the fan furnishes more air in the second case than in the first ; but a
little reflection will show that it is not so. In fkct, the air which issues in a cold
state fVom the tuyere encounters instantly in the furnace a Tery high temperature,
which expands it and contributes, along with the solid matters with which the
furnace is filled, to diminish the facility of the discharge, and consequently to
retard the efflux by the nozzles. The oxygen gas consumed is replaced by a like
volume of carbonic acid gas, equalljr expansible by heat Reason leads us to conclude
that less air flows from the nozzles into the furnace than into the open atmosphere.
The increase in the velocity of the vanes takes place precisely in the Fame manner,
when after having made the nozzles blow into the atmosphere, we substitute for these
nozzles others of a smaller diameter, instead of directing the larger ones into the fur-
nace. Hence we may conceive that the proximity of the charged furnace acts upoo
the blast like the contraction of the nozzles. When the moving power is uniform,
and the velocity of the vanes remains the same, the quantity of air discharged muat
also be the same in the two cases.
Two tuyeres, one 5 inches in diameter, the other 4}, and which, consequently, pre-
sented a total area of 35^ square inches, discharged au* into one of the furnaces, from a
ftp whose vanes performed 654 turns in the minute. These two nozzles being briskly
withdrawn fhim the furnace, and turned round to the f^ air, while a truncated paste-
board cone of 3^ inches diameter was substituted for the nozzle of 4^ inches, whereby
the area of efflux was reduced to 29*3 square inches, the velocity of the vanes continued
exactiy the same. The inverse operation having been perfi>rmed, that is to say, the
two original nozzles having been smartly replaced in the furnace, to discover whether
or not the moving power had changed in the interval of the experiment they betrayed
no perceptible alteration of speed. From the measures taken to oount the speed, the
error could not exceed 3 revolutions per minute, which is idtogether imimportant
upon the number 654.
FREEZING. 295
It followa, dierefbre, that whtu the Tftnet of the fkn hare the Telocity of 664 tnrns
per minate, the expenditure hy two Doaslee, whose joint area is 85^ square inches,
both blowing into a fbrnace, it to the expenditure which takes place, when the same
nosxlet blow into the air, as 85*5 is to 29-3 ; that is, a little more than 4-fiftbs.
If this be, as is probable, a general rule for areas and speeds considerably different
from the above, to find the quantity of air blown into one or more fbmaces by the fan,
we should calculate the volume by one of the abore formults (1) or (2), and take
4*fifths of the resuH, as the true quantity.
The fan A o, represented (Jig, 881), is of the best exeentric form, as eonstructfd by
Messrs. Braithwaite and Ericsson, d is the circular orifice round the axis by which
the air is admitted ; and c c B is the exeentric chanuel through which the air is
wafl«d towards the main discharge pipe a. See VBumLATioN.
FOUNTAIN. A stream of water rising np through the superficial strata of the
earth. See Abtbsian Wbixs.
FOX I NO, is a term employed by brewers to characterise the souring of beer, in
the process of its fermentation or ripening.
FRACTIONAL DISTILLATION. See Naprtba (Boohbad).
FRACTURE of minerals. The fracture of minerals has been grouped under the
Ibllowing heads^ there being Terr few Tariations from them : —
1. Comchoidci; from ocmcha, like a sheR, when a mineral breaks with curred con-
oayities ; example, flint
2. Evem ; when the surfkoe of fracture is rough, with numerous small elcTationa
and depresstOBs.
3. Splintenf; when the broken surface exhibits protruding points.
4. Haekljf; when the elevations are sharp or jagged, as iron.
FRAME^ a mining term. See Obb Drbssing.
FRANKFORT BLACK ; is a bkck used in copper-plate printhig. It is said to be
a enareoal obtained from grape and vine lees, peach kernels, and bone shavings. It is,
doubtful, whether the finest black is not a soot produced from the combustion of some
of these bodies. The preparation is, howerer, made much of a mystery.
FRANKINCENSE. The spontaneous exudations of the Abies exctlea, the Norway
aprvcefir,
FRANKLINITE. A somewhat remarkable mineral, which is found at Hamburg,
K. J., with red oxide of zinc and garnet in granular limestone. Its composition has
been determined to be— .
1.
2. 3.
Oxide of iron
- 66-0
- 68*88 - 6612
Oxide of manganese
- 180
- 18-17 - 1119
Oxide of line
- 17-0
- 10-81 . 21-77
Franklmitewas at first employed for the production of sine ; but for that purpose
it did not answer commercially. It is, however, now employed in combination with
iron, as it is said, with much adyantage. Higor Farrington of New Jersey thus
speaks of it : — ** Many experiments have been made under my superintendence upon the
ores of Franklinite, and I have also witnessed several others of an interesting cha-
racter made by other parties in mixing Franklinite with pig iron in the puddling
furnace, and also a mixture of franklinite pig with other irons in their conversion to
wrought iron. The result in all cases has Iwen a great improvement in the quality of
iron as manuCictured. The most marked and, as I consider, the moat vsluable re-
sult is obtained by using from 10 to 15 per cent of the weight of pig iron to be
puddled with pulverised Franklinite ore m the flimace at each heat. Iron of the
most inferior quality when thus treated, is converted into an article of No. 1 grade.
The volatile nature of zinc at a high temperature, combining with the sulphur, phos-
phorus, and other volatile constituents of the coal, or that may be in the in n,
being carried off meohanicaHy, I consider is one of the causes of the improvemeni ;
the manganese also of the ore combines with silica at a high temperature, and pig
iron that contains silica is thus freed from it The great advantage to be obtsined by
using the pulverised ore in the puddling fhrnace is, that a high grade of iron may be
made *, and where reheating has been hitherto deemed indispensable, one heating is
found sufficient for such uses ss wire billets, nuts, bolts, horseshoe iron, and naila A
particular selection of friel is not required, coke and charcoal can be dispensed with,
and bituminous or anthracite coal used."
FREESTONE. A term used to denote any stone which is capable of being worked
freely in every direction, and, which has no tendency to break in one direction more
than another. In tiie counties of Wicklow and Dublin, and also in Cornwall, the
term is applied to granite which works freely.— H. W. B.
FREEZING. iOmgdoHon^ Fr.; G<»/ri^im^, Germ.) The three general forms,
solid, liquid, and gaseous, under one or other of which idl kinds of matter exist, are
U4
296
FREEZING.
referrible to the inflaence of heat, modifying, halancing, or subduing the attnetion <^
cohesion. Nearly every solid may be liquefied, and every liquid may be vaponaed,
by a certain infusion of heat, whether this be regarded as a moving power, or an
elastic essence. The converse of this proposition is equally true ; for many gaaes, till
lately styled permanent, may be liquefied, nay, even solidined, by diminution of their
temperature, either alone, or aided by a sufficient mechanical condensation, to bring
their particles within the sphere of aggregative attraction. When a solid is trans-
formed into a liquid, and a liquid into a gas or vapour, a quanUty more or less con-
siderable of heat is absorbed, or becomes latent, to use the term of Dr. Black. When
the opposite transformation takes place, the heat absorbed is again emitted, or what
was latent becomes sensible. See Heat for the more recent hypotheses.
The production of cold is a curious and interesting branch of physical inqniry. A
few general laws may be distinctly named.
If a solid body suddenly liquefies, without the application of external heat, it abstracts
from the surrouuding bodies the heat necessary for its liquefaction.
When a salt is dissolved in water cold is produced.
If a liquid vaporises, the vapour is produced at the expense of the heat of some
neighbouring body.
When spirits of wine, or ether, is thrown on the body, a sensation of coldness is
produced from the liquids vaporising by robbing the body of heat
By placing water in a porous vessel, and exposing it to the sun« it becomes very cold.
The solar heat-rays occasion a rapid evaporation of the water which has filtered through
the pores of the vessel, and some heat is taken by the process from the fluid in the
interior.
If air is allowed suddenly to expand, it takes heat from the surrounding bodies, or
produces cold.
The most fiimiliar method of producing intense cold is by means of freezing mixtures.
A great number of those were invented by Mr. Walker ; the principal results are con-
tained in the following tables: —
L — Table, consisting of Frigorific Mixtures, having the power of generating or
creating cold without the aid of ice, sufficient for all useful and philosoplucal porposes,
in any part of the world at any season.
Frigorific Mvvtttres without Zee.
MIXTURES.
Nitrate of ammonia
Water
1 part
1
Thennometer sinks.
Muriate of ammonia
Nitrate of potash
Water
5 parts
5
16
Muriate of ammonia
Nitrate of potash
Sulphate of soda
Water
5 parts
5
8
16
Sulphate of soda
Diluted nitric acid
Nitrate of ammonia
Carbonate of soda
Water
d parts
S
1 part
1
1
From
+
SO^to
+
40
From
+
50® to
+
IQO
From
+
50® to
+
4«>
From + 60°to- 8°
From + 60<^ to — 7®
Phosphate of soda
Dilute nitric acid
Sulphate of soda
Hydrochloric acid
9 parts
4
8 parts
5
Sulphate of soda
Dilute sulphuric acid
5 parts
4
Sulphate of soda
Muriate of ammonia
Nitrate of potash
Dilute nitric acid
6 parts
4
a
4
Sulphate of soda
Nitrate of ammonia
Dilute nitric acid
6 parts
5
4
From
60° to ■
- 12°
From
+
5QPto(P
From
+
50° to
+ 3°
From
+
50° to
-IQP
Deg. of cold
46«
40
46
53
57
62
50
From + 50° to - 14°
47
60
64
FREEZING.
297
IT. — TaUe eoDsisting of Frigorifio Ifixtures, composed of ice, with chemical salts
and acids.
Frigorifie Mixtures with Ice.
MIXTURBa.
Tbennoiii0ter tinki.
Deg. of cold
produced.
Snow, or pounded ice • 2 parts
Muriate of soda - - t
From any temperature
- *
to-5°
•
Snow, or pounded ice - 5 parts
Muriate of soda - - - 2
Muriate of ammonia - - 1
to- 12°
•
Snow, or pounded ice - 24 parts
Muriate of soda - • 10
Muriate of ammonia - - 5
Nitrate of potash . . 5
to- 18°
•
Snow, or pounded ice - 12 parts
Muriate of soda - - 5
Nitrate of ammonia - - 5
to-25°
•
Snow - ... 3 parts
Dilate sulphuric acid • 2
From + 32° to - 23^
55
Snow .... 8 parts
Muriatic acid ... 5
From + 32<> to - 27°
59
Snow .... 7 parts
Dilute nitric acid - - 4
From + 32® to - 30°
62
Snow - - - . 4 parts
Muriate of lime - - 5
From + 82° to — 4(fi
72
Snow - ... 2 parts
Cryst muriate of lime - 8
From + 820 to - 60°
82
Snow - ... 3 parts
Potash .... 4
From + 82° to — 51°
83
N. B. — The reason for the omissions in the last column of the preceding table is,
the thermometer sinking in these mixtures to the degree mention^ in the preceding
column, and neTer lower, whatever may be the temperature of the materials at mixing.
To produce these results in a satisfactory manner, it is necessary to cool previoosly
to the experiments, the vessels in which the mixtures are made.
The most intense cold that is as yet known is that trota the evaporation of a mixture
of solid carbonic acid and sulphuric ether, by which a temperature of 166^ Fahr.
below the freesing point of water is produced. By means of this intense cold, assisted
by mechanical pressure several of the gaseous bodies have been condensed into liquids,
and in some instances solidified.
Sir John Herschel, some years since, recommended the following method for obtain-
ing at moderate cost large quantities of ice.
A steam engine boiler was to be sunk into the earth, and the quantity of water
which it was desired to f^eze placed in it By means of a condensing pump, several
atmospheres of air were forced into the boiler, and then everything was allowed to
remain for a night, or until the whole had acquired the temperature of the surround-
ing earth. Then, by opening a stop cock, the air expanding escaped with much violence,
and the water being robbed of its heat to supply the expanding air, the temperature
of the whole was so reduced, that a mass of ice was the result
The following process for producing cold has been patented and exhibited in this
country.
In a reservoir, or what may with propriety be called a boiler, was placed a quantity
of sulphuric ether. This reservoir was placed in a long vessel of saline water, this
fluid by the arrangement being made to flow from one end of the trough to the other,
that is to and fnm the reservoir. In Uiis water was placed a number of vessels, the
depth and breadth of the trough, but of only two inches in width, and these were
filled with the water to be frozen.
A steam engine was employed to pump the air from the reservoir ; this being done,
of course the ether boiled, and the vapour of the ether was removed by the engine as
fiist as it was formed. The heat required to vaporise the ether was derived from the
saline water in the trongh, and this again took the heat from the water in the cells;
thus eventually every cell of water was converted into ice. The ether was, after it
had passed through the engine, condensed by a refHgeratory of the ordinary kind.
298 FUEL.
The statement made by the patentee was very flatiafiuitory, as it regarded the eost of
production. An apparatos of this kind is of coarse intended for hot countries only,
where ice becomes actually one of the necessaries of life.
A peculiar physical fact connected with the freezing of water has been made a^ail-
able to some important uses. Water in freezing really rejects everything it may
contain — even air, and hence solid ice is actually pure water. This may be easily
proved. Make a good freezing mixture, and place some water in a flask, and while
it is undergoing consolidation by being placed in the frigorific compound, gently
agitate it with a feather. Now, if the water contains spirit, acid, salt, or colouring
matter, either of them are alike rejected, and the solid obtained, when washed from
the matter adhering to its surface is absolutely pure solid water.
This philosophic fact, although it has only been subjected to ezaminatioii within
the last few years, has been long known.
Byron, in his 13th Canto of Don Juan, has the following allusion to it : —
" ril have another figure In a trice :
What say you to a bottle of chanpagoe f
Froien into a very vlnoui ice.
Which leaves few drops of that Immortal rain.
Yet In the very centre, past all price.
About a liquid glassful will remain ;
And this is stronger than the strongnt grape
Could e*er express in its expanded shape.**
The old nobles of Russia, when they desired a more intoxicating drink than usual,
placed their wines or spirit in the ice of their frozen rivers, until all the aqueous
portion was frozen ; when they drank the ardent fluid accumulated in the centre.
This plan has been employed also for concentrating lemon juice and the likeu For
some further matters connected with this peculiar condition, see Steam Boiubba and
Water.
FRENCH BERRIEa The berries of the JRhamnvs caOiartinu, and other species
of the Buckthorn. The true French berries, which should be four-seeded, belong to
the first named ; all the two-seeded berries are obtained from other and inferior kinds.
FRENCH CHALK. A steatite ; a soft magnesian mineraL
FRENCH POLISH. There are numerous methods given for the preparation of
this polish, one of the best is probably the following : 1^ lbs. of shell lac dlissolved in
a gallon of spirits of wine without heat Another recipe is 12 ounces of shell lac, S
ounces of gum elemt, and 8 ounces of copal to 1 gallon of spirits of wine.
FRICTION. The resistance to motion which depends on the structure of the
surfkces in contact Friction is usually divided into two kinds: diding friction and
roUing /riction. The questions involved in the consideration of friction are purely
engineering, and cannot therefore be treated here. One Tery important element may
however be named, as showing the importance of exact science in connection with
the improvements in mechanics. By friction heat is evolved. It is found by accurate
experiment, that the quantity of heat evolved is exactly sufficient to reproduce the effort
caused in overcoming me friction. — Joule and Thomson..
FRIT. See Enamel and Glass.
FUCUS. S^ee Algjl In the Fucus serratus and ceramoides silver has been de-
tected, Malaguto has stated, to the extent of j^^, in the ashes of these plants. It
has also been stated that these and some other plants contain lead and copper.
FUD, or WOOLLEN WASTE, is the refrise of the new wool taken out in the
scribbling process, and is mixed with the mungo for use. See MuNoa
FUEL. {Combustible, Fr; Brennstoff, Germ.)
Such combustibles as are used for fires or furnaces. Wood, Tur^ Coal, are fkmiliar
examples. Fuels differ in their nature, and in their power of giving heat, it is there-
fore of much importance to ascertain the heat-giving power. Numerous excellent
experiments have been made for the purpose of determining with exactness the heating
values of fuels of different kinds. Lavoisier and Laplace, in an extensive examination
carried out by them, used the well known Calorimeter, that is, they determined die
value of the heat by the quantity of ice melted in a given time. Count Rumford sub-
sequently measured the quantitv of heat by the increase of temperature in a given
quantity of water. The quantity of heat which will melt I lb. of ice at O® Cent
being just sufficient according to Laplace to raise the temperature of a pound of water
to 75<* Cent., or according to the experiments of Regnanlt, to 79^ Cent. Clement and
Desormes have also shown, that an equal weight of aqueous vapour, whatever may be
its temperature and tension, is always produced by one and the fame amount of heat
As far as we can within the limits of the present work, we shall endeavour to present
a full practical view of the subject, giving each class of fuels under their several
heads.
I. Wood, which is divided into hard and soft To the former belong the oak.
FUEL.
299
the heech, the alder, the hirch, and the elm ; to the latter, the fir, thepme of different
sorts, the larch, the linden, the willow, and the poplar.
Under like dryness and weight, different woods are fonnd to afford very different
degrees of heat and combustion. Moisture diminishes the heating power in three
ways : by diminishing the relative weight of the ligneoos matter, by wasting heat in
its eTsporation, and by causing slow and imperfect combustion. If a piece of wood
contain, for example, 25 per cent of water, then it contains only 75 per cent of fuel,
and the evaporation of that water will require ^ part of the weight of the wood.
Hence the damp wood is of less value in combustion by j^ or } than the dry. The
quantity of moisture in newly felled wood amounts to fVom 20 to 50 per cent ; birch
contains SO, oak 85, beech and pine 39, alder, 41, fir 45. According to their different
natures, woods which hare been felled and cleft for 12 months ooutain still from 80 to
25 per cent of water. There is never less than 10 per cent present, even when it
has been kept long in a dry place, and thoueh it be dried in a strong heat, it will after-
wards absorb 10 or 12 per cent of water. If it be too strongly kiln dried, its heating
powers are impaired by the commencement of carbonisation, as if some of its hydrogen
were destroyed.
The following table, compiled from the researches of Count Rnmford, will place
these points dearly before us.
OiM pound of th« following woods
when bttrnt will heat :
Lame tree
Beech
Elm -
Oak
Ash -
Sycamore
Fir -
Poplar
Poundi of water f^om 0^ to 1W> Cent.
Ordinary condition.
34*708
33*798
30-205
25*590
30*666
30*322
34*601
Slightly dried.
38*833
29*210
33*720
34*000
Strooglr dried.
40*181
36*746
34*083
29*838
35*449
36-117
37*379
87*161
From every combustible the heat is diffused either by radiation or by direct communi-
cation to bodies in contact with the fiame. In a wood fire the quantity of radiating heat
is, to that diffused by the air, as 1 to 3 ; or it is one fourth of the whole heating power.
II. ChareoaL — The different eharc€«l8 afford, under equal weights, equal quantities
of heat We may reckon, upon an average, that a pound of dry charcoal is capable of
heating 75 pounds of water from the freesing to the boiling point ; but when it has
been for some time exposed to the air, it contuns at least 10 p«r cent of water, which
is partially decomposed in the combustion into carburetted hydrogen, which causes
flame, whereas pure dry charcoal emits none.
Winkler gives the following as the results obtained by him with charcoal fi-om various
sources:
1
Charcoal Arom : (
I
Pounds of water heated
Vom 00 to lOQO Gent.
9f 1 pound of charcoal.
Air required for per-
fect combustion.
Pounds of lead reduced
by 1 pound of charcoal.
Poplar - - -
Sycamore - - -
Fir - - - -
Ash -
Birch
Oak - - - -
Elm - - - -
Willow
Pine - - - -
On an average
75*7-
On an average
293*5 cubic feet •
at 19° Cent
33*56
33*23
33*51
33*23
33*71
33*74
33*26
33*49
33*53
A cubic foot of charcoal from soft wood weighs npon an average firom 8 to 9 pounds,
and from hard wood 12 to 13 pounds ; and hence the latter is best adapted to main-
tain a high heat in a small compass. The radiating heat from charcoal fires consti-
tutes one third of the whole emitted.
III. Turf or peat — - One pound of this fhel will heat according to its quality, from
18 to 42 pounds of water from freezing to boiling. Its value depends upon iu com-
300 FUEL.
Eactness and freedom from earthy particles ; and its radiating power is to tlie whole
eat it emits in burning as 1 to 3.
According to Berthier, the following results were obtained from peat : —
Source or the Peat. Poandi of water heated br 1 jmund
of peat from (P to 100" Cent.
FromTroyes 181
„ department de la Somme - * • - 27 9
„ „ de la Marne - - - - 29*2
„ „ de la Vosges - - - - 34-9
„ n desLandcs - - - - • 34*6
Winkler gives 2 6 '9 as the evaporative power of the worst Hanoverian peat, and
42*6 as that of the best
Peat obtained from the Bog of Allen gave, according to Griffith (the discrepancies
between the results we do not understand) : —
Poondi of water heated fhxn
(JP to lOOO Cent.
Upper peat ------- 62*7
Lower peat ------- 66*6
Pressed peat 28-0
IV. Coal. — The varieties of coal are almost indefinite, and give out very various
quantities of heat in their combustion. The carbon is the heat* giving constituent,
and it amounts, in different coals, to from 75 to 95 per cent One pound of good coal
will, upon an average, heat 60 pounds of water from the freezing to the boiling point
Small coal gives out three-fourths of the heat of the larger lumps. The radiating beat
emitted by burning pitcoal is greater than that by charcoal.
V. The coke of coal. — The heating power of good coke is to that of pitcoal as 75
to 69. One pound of the former will heat 65 pounds of water from 32^ to 212^ ; so
that its power is equal to nine-tenths of that of wood charcoaL
Berthicr gives as the results of his trials : -^
Pounds of water heated bf 1 pound
of coal from (P to 100 C.
Dowlais coal -..-.. 72*0
Glamorgan - - - - - - 70*7
Newcastle - - - - - - . 70*0
Derbyshire • • - - - -61 6
Lancashire (cannel) - . . . . 53'3
Durham -•..... 71/5
Coke (St Etienne) 65*6
Do. gas from Paris - . - - . 50*3
YL Carhuretted hydrogen or coal gas, — One pound of this gas, equal to about 24
cubic feet, disengages in burning as much heat as will raise 76 pounds of water from
the freezing to the boiling temperature.
In the following table the fourth column contains the weight of atmospherical air,
whose oxygen is required for the complete combustion of a pound of each particular
substance.
Pounds of water
Poundi of boiling
Weight of atmospberic
Spedei of combuitlble.
which a pound can
water evaporated by
air at KP, to bum
heat ftom OP to tlV>.
1 pound.
1 pound.
Perfectly dry wood
35-00
636
5-96
Wood in its ordinary state
26-00
4-72
4-47
Wood charcoal
73-00
13-27
11-46
Pitcoal - - - -
60-00
10-90
9-26
Coke - - . -
65-00
11-81
11-46
Turf - - - -
3000
5-45
4-60
Turf charcoal
64-00
11-63
986
Carhuretted hydrogen gas
Oil ^
76-00
13'81
14-58
Wax i» - - -
7800
14-18
15-00
Tallow ^
Alcohol of the shops
52-60
9-56
11-60
The quantity of air stated in the fourth column, is the smallest possible required to
bum the combustible, and is greatly less than would be necessary in piwctice, where
FUEL. 301
mach tit the ur never comes into contact irith the barning body, and where it con-
seqoently nerer has its whole oxygen consumed. The heating power stated in the
second colamn is also the maximum effect, and can seldom be realised with ordinary
boilers. The draught of air usually carries off at least 4 of the heat, and more if its
temperature be very high when it leaves the vessel. In this case it may amount to one
half of the wh(de heat, or more ; without reckoning the loss by radiation and conduction,
which however uotj be rendered very small by enclosing the fire and flues within
proper non-conductmg and non-radiating materials.
It appears that, in practice, the quantity of heat which may be obtained from any
combustible in a properly mounted apparatus, must vary with the nature of the object to
be heated. In heating chambers by stoves, and water boilers by furnaces, the effluent
heat in the chimney, which constitutes the principal waste, may be reduced to a very
moderate quantity, in comparison of that which escapes from the best constructed
reverberatory hearth. In heating the boilers of steam engines, one pound of coal is
reckoned adequate to convert 7^ pounds of boiling water into vapour ; or to heat 41 i
pounds of water from the freesing to the boiling point One pound of fir of the usual
dryness will evaporate 4 pounds <n water, or heat 22 pounds to the boiling temperature ;
which is about two-thirds of the maximum effect of this combustible. According to
Watt's experiments upon the great scale, one pound of coal can boil off with the best
built boiler, 9 pounds of water ; the deficiency from the maximum effect being here
If, or nearly one sixth. See the Tablet at the end of thie article.
In many cases the hot air which passes into the flues or chimneys may be bene-
ficially applied to the heating, drying, or roasting of objects ; but care ought to be taken
that the draught of the fire be not thereby impaired, and an imperfect combustion of
the fuel produced. For, at a low smothering temperature, both carbonic oxide and
carburetted hydrogen may be generated from coal, without the production of much
heat in the fireplace.
To determine exactly the quantity of heat disengaged by any combustible in the act
of burning, three different systems of apparatus have been employed : 1, the calori-
meter of Lavoisier and Laplace, in which the substance is burned in the centre of a
vessel whose walls are lined with ice, and the amount of ice melted measures the
heat evolved ; 2, the calorimeter of Watt and Rumford, in which the degree of heat
communicated to a given body of water affords the measure of temperature ; and .S, by
the quantity of water evaporated by different kinds of fuel in similar circumstances.
The first and most celebrated, though probably not the most accurate apparatus for
measuring the quantity of heat transferable from a hotter to a colder body, was the
calorimeter of Lavoisier and Laplace. It consisted of three concentric cylinders of tin
plate, placed at certain distances asunder ; the two outer interstitial spaces being filled
with ice, while the innermost cylinder received the hot body, the subject of experiment.
The quantity of water discharged ft*om the middle space by the melting of the ice in it,
served to measure the quantity of heat given out by the body in the central cylinder.
A simpler and better instrument on this principle would be a hollow cylinder of ice of
proper thickness, into whose interior the hot body would be introduced, and which
would indicate by the quantity of water found melted within it the quantity of heat
absorbed by the ice. In this case the errors occasioned by the retention of water among
the fragments of ice packed into the cylindric cell of the tin calorimeter, would be
avoided. One pound of water at 172^ Fahr., introduced into the hollow cylinder
described, will melt exactly one pound of ice ; and one pound of oil heated to 172^ will
melt half a pound. — Ure.
The method of refrigeration, contrived at first by Meyer, has been in modem times
brought to great perfection by Duloog and Petit It rests on the principle, that two
surfaces of like size, and of equal radiating force, lose in like times the same quantity
of heat when they are at the same temperature. Suppose, for example, that a vessel of
polished silver, of small size, and very thin in the metal, is successively filled with dif-
ferent pulverised substances, and that it is allowed to cool from the same elevation of
temperature ; the quantities of heat lost in the first instant of cooling will be always
equal to each other ; and if for one of the substances, the velocity of cooling is double
of that for another, we may conclude that its capacity for heat is one half, when its
weight is the same ; since by losing the same quantity of heat, it sinks in temperature
double the number of degrees.
The method of mixtures. — In this method two bodies are always employed ; a hot
body, which becomes cool, and a cold body, which becomes hot in such manner that all
the caloric which goes out of the former is expended in heating the latter. Suppose,
for example, that we pour a pound of quicksilver at 212° F., into a pound of water at
32°; the quicksilver will cool and the water will heat till the mixture by stirring ac-
quires a common temperature. If this temperature was 122°, the water and mercury
would have equal capacities, since the same quantity of heat would produce in an equal
302
FUEL.
mass of these two subetaaces equal changes of temperature, tis., a& elevatum^f 900 ut
the water and a depresoon of 90^ in the mercury. But in reality, the mixture is found
to have a temperature of only 37^^, showbg that while the mercury loses 1744<' the
water gains only 5^^ ; two numbers in the ratio of about 32 to 1 ; whence it is concluded,
that tlM capacity of mercury is jg of that of water. Corrections must be made for the
influence of the vessel and for the heat dissipated during the time of the experimeuL
If our otgect be to ascertain the rdatire heating powers of different kinds of fuel, we
need not care so much about the total waste of heat in the experiments, proTided it be
the same in all ; and therefore they should be burned in the same furnace, and in the
same way. Bat the more econonucaliy the heat is applied, the greater certainty will
there be in the results. The apparatus,/^^. 882,
is simple and well adapted to make such com-
parative trials of fuel. The little furnace is
coTcred at top, and transmits its burned air by e,
through a spiral tube immersed in a cistern of
water, having a thermometer inserted near its
top, and another near its bottom, into little side
orifices, a a, while the effluent air escapes from
the upright end of the tube b. Here also a ther-
mometer bulb may be placed. The average in-
dication of the two thermometers gives the meaa
temperature of the water. As the water ewmpo"
rates from the cistern, it is supplied fh>m a yeaaei
placed alongide of it The experiment should
be begun when the furnace has acquired an
equability of temnerature. A throttle valve at c serves to regulate the draught, and
to equalise it in the different experiments by means of the temperature of the effluent
air. When the water has been heated the given number of degrees, which should be
the same in the different experiments, the fire may be extinguished, the remaining fuel
weighed, and compared with the original quantity. Care should be taken to make the
combustion as vivid and free fh>m smoke as possible.
The following calorimeter, founded upon the same principle as that of Count Rum-
ford, but with certain improvements, may be consideied as an equally correct instru-
ment for measuring heat with any of the preceding, but one of much more ^neral
application, since it can determine the quantity of heat disengaged in combustion, as
well as the latent heat of steam and other vapours.
It consists of a large copper bath, e,/(Jig, 883), capable of holding 100 gallons of
Scale about | inch to the square foot.
water. It is traversed four times, backwards and forwards, in four different levels,
by a zig-zag horizontal flue or flat pipe J, c, nine inches broad and one deep, ending
below in a round pipe at c, which passes through the bottom of the copper bath €,/,
and receives there into it the top of a small black lead furnace b. The innermost
crucible contains the fuel. It is surrounded at the distance of one inch by a second
crucible, which is enclosed at the same time by the sides of the outermost furnace ;
FUEL. 808
the ■CMita of stagnant air tetween the eineibka senring to prevent the heat from being
diottpated into the atmosphere round the body of the lomaoe. A pipe a, from a pair
of cylinder double bellows, enters the ash-pit of the fbmace at one side, and supplies
a steady bnt gentle blast, to carry on the combustion, kindled at first by half an ounce
of red-hot charooaL So completely is the heat which is disengaged by the bumiog
fuel absorbed by the water in the bath, that the air discharged at we top orikce g has
usually the same temperature as the atmosphere.
The Teasel is made of copper, weighing two pounds per square foot ; it is 5^ feet
long. 1^ wide, 2 deep, with a bottom 5^ feet long, and if broad, upon an average.
Including the sig-sag tin plate flue, and a rim of wrought iron, it weighs altogether
85 pounds. Since the specific heat of copper is to that of water as 94 to 1,000, the
specific heat of the vessel is equal to that of 8 pounds of water, for which, therefore,
the exact correction is made by leaving 8 pounds of water out of the 600 or 1,000
pounds used in each experiment.
In the experiments made with former calorimeters of this kind, the combustion was
muntained by the current or draft of a chimney open at bottom, which carried off at
the top orifice of the flue a variable quantity of heat, very difilcult to estimate.
\¥hen the olgect is to determine the latent heat of steam and other Taponrs, they
may be introduced through a tube into the top orifice o, the latent heat being deduced
frt)m the elcTation of temperature in theiwater of the oath, and the volume of vapour
expended from the quantity of liquid discharged into a measure glass fr^m the bottom
outlet e. In this case, the furnace is of course removed.
The heating power of the fhel is measured by the number of degrees of temperature
which the combustion of one pound of it, raises 600 or 1,000 pounds of water in the
bath, — ^the copper substance d the vessel being taken into account.
It must be borne in mind that a coal which gives off much unbumt carburetted hy-
drogen gas does not afford so much heat, since in the production of the gas a great
deal of heat is carried off in the latent state.
The economy of fuel, as exhibited in the celebrated pumping engines of Cornwall,
will be dealt with under the proper head. See Steam Ehoins. And in reference to
the ordinary uses of fuel for domestic and other purposes, see Stoves.
Patent Fuel. Under this name a great many attempts have been made to utilise
wa*>te material. In countries where charcoal is abundant charcoal dust mixed with
pitch has been employed, and attempts have been made to utilise the immense quantities
of saw-dust produced in the north of Europe, by mixing it with clay and tar. Parsing
over the several kinds of artificial fuel which have been made on the continent, the
productions of this character made in this country must be described.
Wylam's patent fuel is small coal and pitch moulded together into bricks by pressure.
The pilch is obtained by the distillation of coal tar fh>m which naphtha and a peculiar
oil are separated, leaving the pitch. This pitch is ground fine and mixed with small
coal, and in this state it is passed, by a very ingenious application of the Archimedean
screw, through a retort maintained at a dull red heat, by which it is softened for
being' mouhM, which is effected by a kind of brick-making machine under enormous
pressure,
Warlich's patent fuel is similar in character, but he adds a little common salt or
alum to prevent the evolution of too much smoke, and the fuel bricks are subjected to
a temperature of 400^ F. for eight hours, by which the more volatile constituents are
driven off.
Wood's fhel is prepared by mixing small coke or coal in a heated state with tar or
pitch in a common pug-mill, after which it is moulded in the ordinary manner.
Be8semer*s process consists merely in exposing coal-dost to a temperature of 600^
F. By this the bituminous matter of the coal becomes softened, and the whole can be
pressed into a firm block.
Grant's patent This fbel is composed of coal-dust and coal-tar pitch ; these mate-
rials are mixed together, under the iofluence of heat, in the following proportions: —
20 lbs. of pitch to 1 cwt of coal-dust, by appropriate machinery, consisting of cnish-
irg-rollers for breaking the coal in the first instance sufficiently small so that it may
pass through a screen, the meshes of which do not exceed a quarter of an inch asunder;
2ndly, of mixing-pans or cylinders, heated to the temperature of 220^, either by steam
or heated air ; and, Srdly, of moulding machines, by which the fuel is compressed,
under a pressure equal to five tons, into the size of a common brick ; the fuel bricks
are then whitewashed, which prevents their sticking together, either in the coal
bunkers or in hot climates. The advantages of these artificial fuels over coal may be
stated to consist, first, in its efficacy in generating steam ; secondly, it occupies less
space; that is to say, 500 tons of it may be stowed in an area which will contain only
400 tons of coal; thirdly, it is used with much greater ease by the stokers or firemen
than coal, and it creates little or no dirt or dust, considerations of some importance
304
FUEL.
vheD the delietM muhineTT of* ttetm-eDgiDe ii coniideTed ; finiTthly, it pradooM a
Terj amill proportion of clinkcn, nnd ihua it ii &r ten liable to cbokc and Atttiof
the ruTUiee ban and boilen iban ca*l -, fifihlj, [he igojtioa it lo complete that com-
paratiTely little imoke, ind only s gmall quaotit; of uhes, »re produced hj it ; (ixlbl^,
from the mixture of Ihe patent fuel, and the manner of ill roanafacture, it ia not liable
to enter iuto tpontaneouj ignition.
A great man; other persons have either patented proceties for the preparation of
arlificial fuel, or publlahed iiiggeatioDi. Theae are ao nearljr aliiie that a few of th«ic
■e any u
Jobbold agilatea peal in
peat to eubaide. and coiuolidi
Godwin make> brick of m
Oram employ! tar, coali, i
Hitl tskea the regiduary mailer after Che dislilUlion of peat, ai
Holland mixes lime or cement with tar and gmall coals.
Kaasome cements small coal together by a eolation of silicate of soila-
From the Admiralty Coal Inquiry's Report we obtain the following analyaea of
■everal of the more important artificial fnela : —
' to separate the earthy matter, aikd tlien allow* the
' clay with piti:h or coal.
lud.
n it with pitch.
"rj."
OlJKB.
Warlich's -
1-15
90'02
6-S8
1-62
2-91
LiTingstone's
I-IB
BS'Or
413
149
2-03
4-9!
I.yon'i
1-13
86 36
4-56
1-29
2-07
4-G6
Beira
I'U
87-88
5-22
0-71
0-43
HolUnd and Green's -
f30
70-U
4-65
Wykm's - - -
110
J9-91
969
125
6-63
4-54
..^.^.^^
jl
j
1
Ab-r.lve Hlwn C^l -
Bl'chgton r.Hlgolt -
BlHixlurt Dl| Swn -
sssis,?"''" :
Ditto 3-rirtl Vein
»iiio i-im V^n
SOS-a? : :
CmI T>1™ . . .
^°'.'i:«"*^"'B*m :
C.mf'wdRockVrtn-
El'Hir lliril SKun Coal
Kul'4 Colliery - '
Ouiln EJf> CaUlwT Coal
m
SS ^^
nf^"Z\^
LI||htl>ra>aniol
Brnii'n,lir|*<l>l»l
FUEL.
805
DMeripdon of tlM FimI tried.
1^
Gellte Cadoxtan Steam Coal
Ditto Steam Coal ...
GoItbo* .....
Gralgola Steam Coal ...
Ditto ditto (handpicked)
Gwythen Charcoal Vein
Ditto ditto
Little Raltfa Lochgelly
Llanelly
Llangenn^ck ....
Ditto (handpicked) .
Lochgellj Coal ....
Macheo Black Vein ...
Machen Rock Vela ...
Merthjr
Ditto - . . . -
Ditto Aberaraon • • .
Ditto Aberdare ...
Ditto ditto FotherglU'c .
Ditto Crocileld . . .'
Ditto ditto and Gadlejr'c
Ditto (handpicked)
Ditto Nixon's . . .
Ditto Wenslejdale. •
Ditto Wood's . • - .
Horfo Steam Coal ...
Ditto ditto Vivlan'i .
Neiriir* Llanelly '. . . .
Mew Black Vein Steam Coal
NewelUoo
PoveU's Duflyrn >
Resolven
Ditto (handpicked)
Ditto ditto
Risca Rock Vein .
Rock Vein .
Squborwen Merthyr
Thomas' Merlhvr .
Tillery Btc Vein -
Wagniu' Merthyr.
Waynes* Merthyr -
Welsh Coal . -
NOMTB COUNTST COALSl
Alloa Colliery
Atherton Steam Coal
Barlieth and Dollar's Steam Coal
Ditto Steam Coal •
Bates' Hartley .
Ditto Weat Hartley .
Bebside Colliery Coal -
Bell's Primrose .
BonrtreehlU Coal .
Buddl«'s Hartley -
Ditto West Hartley
Carr's Hartley >
CHackmannaa
Cuttlehill ...
Derwentwater, Radcliffe Colliery
Ditto Weat Hartley
Barsdon's Hartley
Garforth's Hartley .
Garforth Steam Coal .
Garswood Park ...
GawberHall ...
Ditto Steam Coal .
Cover Coal ....
Gtfj't Broomhlll ...
Grimsby Coal, Sheffield Railway
Halsnead Coal ...
Hartley Coal ...
Ditto Bates* West -
Ditto Belmont -
Ditto Buddie's
Ditto ditto West
Ditto Carr's ...
Ditto ditto West «
Vol. II.
a
9
1
8
1
1
4
S
1
9
9
9
1
1
98
4
1
8
43
9
1
8
6
1
1
1
9
9
9
1
1
9
1
1
1
9
19
9
9
9
I
9
9
4
1
4
I
a
4
3
1
23
88
9
3
1
1
1
3
9
9
1
9
6
9
6
1
a
9
1
9
4
17
15
1
8-91
8-M
9*02
8 89
8*84
8-21
8*95
7-27
8-43
6-81
8-44
7-66
8*81
8-32
8-78
9-06
8-63
8-76
8-51
9-37
8-66
8-92
8-78
8-91
8-87
8-53
8-6
8-56
9-56
8-97
9-08
9-06
8 64
915
8-26
86
8*93
9-28
8-89
8-79
8 98
9-33
8-89
822
7-96
8-32
6-71
7-7
814
9-46
7*56
7-79
8-06
805
809
7-72
8-27
7-69
8-25
8-06
712
7-99
8-14
7-84
783
8-04
7-46
7-48
774
7-39
8-4
7-8
7-82
8*19
835
49-97
43-83
4a-62
35-59
4102
47-55
48 16
4&>€a
46-43
46-52
44-92
46-06
50-44
47-27
4542
48-17
47-72
46-78
44-79
45*14
46-12
45-84
45-54
45-84
43-7
44-63
44-94
47-59
M-67
48-96
48-26
48-1
45-39
49-79
46-67
48-11
46-51
49-99
61-99
47*25
48*43
48-62
56-07
48-76
49-45
49-39
45-66
46-41
49*82
45-67
4V96
47 98
48-34
48-63
45*39
4267
50-22
4H-23
6012
60*11
40-33
51-61
42-49
4301
44-58
48-87
45-84
47*23
4578
48-27
46-3
45-61
46*33
45-45
48 43
*G8
*87
-69
-42
-71
-95
2-7
9'/
96
i-Sf<
203
1
1
37
1-02
6<i
41
1-61
1-47
l-25>
*9I
1-13
•98
•61
•67
I'I*i
1-3
-i-03
79
2*21
1-35
1-77
54
1-75
87
2-39
l*8f
1-84
1*07
l-7f:
171-
1*76
1*01
74
46
1-29
2 Itc
1-34
9.'«
24
1-27
1-49
1-41
171
•67
l-l
1-67
71
•61
1-26
119
lO."*
I-«ft
-9i
114
1-69
1-24
1-06
-66
1-43
1*15
1-28
1-29
1
5*7
6*21
3-91
6 6f>
5-52
44
3-8
7-43
6-8
6-41
5*73
4*19
5-39
4-78
5-54
4*56
3-9T
4*06
458
6-38
7*53
4-8-J
4-34
6-49
5-68
463
5-23
5-8
5-751
25
81
48
4
22
89
61
57
4H
2?
16
SOf
93
17
17
!:<
23
6
68
6:
0**
47
7(
4-7P
5-7)
3-8
4-7/
4-881
57f
6-6
5-21)
4-11
68
5-2S
5 66
4-24
3-6&
5-77
7 07
3-97
4-11
4-09
3-93
5'68|
BoMAt.
7*38
9-09
5-6
8*11
6-*i3|
6-3.'
6-51
835
876
8*77
7761
4-2V
7-49
616
6-dC
623
5-4C
5*6:
6
7-63
8-44
5-96
5-32
7-1
6*3f»
575
654
7-83
6*54
8*46
8*16
7-26
4*89
6*15
70H
828
7-85
6-46
5'64
824
7-02
7-9-^
6-04
5-67
4-63
5-46
624
6-56
5-55
9-08
5-94
5*.'>H
5*87
5-47
543
6 39
5-59
6-36
6-86
6-4!'
5 n:
7-05
621
6-7V
593
4 93
6-83
7*73
5-41
527
5-38
614
6-88
Very light smoke:
No record.
Black smoke.
No smoke.
No record.
Light smoke.
No smoke.
Much light smoke.
No record.
No smoke.
Ditto.
Light smoke.
Black smoke.
Muchbla<k smoke.
Light smoke.
Ditto.
Ditto.
No record.
Light smoke.
,No record.
Ditto.
Ligiit smoke.
Ditto.
No record.
Ditto.
Black smoke.
Much black smoke.
Light SHioke.
Large quantity of
brown smoke.
No record.
Light smoke.
Light brc-vn.
No record.
Ditto.
Ditto.
Ditto.
Light smoke.
No record.
Ditto.
Ditto.
Very light nnoke.
No record.
Little black smoke.
Black smoke.
Black, moderate
auantity.
Light brown.
No record.
Black £.-no*e.
Ditto .
No record.
Much smoke.
Doric smokt-.
Black smoke.
Black, large quan-
tity.
Black smoUe.
No record.
Black smokt.
No record.
Great quntity of
black smuke.
HeMTy smoke.
Light smoke.
No rrcord.
Ditto.
Light smoki.
Black smoke.
Heavy biark smoke.
No record.
Dark (moke.
No record.
Heavy black smoke.
No record.
Mucii smoke.
Black smoke.
Dark smoke.
H0a?y black»
306
FUEL.
D«Mrl|itJon oftbe Furi tried.
Namber of Trlato fttm
which the ATeragc
renilu are deduced.
Cubic Feet of Water
eraporatcd per Hour,
calculated from lOO^
conMant Tempera-
ture of the Veod
Water.
•
1
•
r
a,
4*7
11
1"
Snoke^
Hartley. Clifton** We»t
7'91
45-02
1*48
6-05
Ditto.
Ditto Cowpen ....
7-63
44-87
73
5-94
6-68
No record.
Ditto Frnham't ...
21
8-53
43-47
207
5^1
7-17
Heary black.
Ditto ditto West -
8-87
42-41
2-89
6-25
9*14
Ditta
Ditto Hetlley*s
8-4
4702
1-29
2-91
4-2
No record.
Ditto Hetton Wext -
8*45
47-39
1-18
698
8-16
Diuo.
Ditto Howard's West Netherton
7-67
46-22
1-35
68
8 15
Ditto.
Ditto Jonasftohn't ...
809
4912
•88
5^34
6-23
Little black fmoke.
Ditto Longridge West -
7-82
47-57
1-46
8«75
6-21
No record.
Ditto ditto Best >
7-86
46 1
l-lH
889
4-57
Light smoke.
Ditto Morpeth. ...
7-87
47-58
1-52
4-7
6 22 Little black smoke.
Ditto Newcastle ...
8*49
4*^41
207
5-73
7-81
No record.
Ditto Wellington West -
889
42*48
1-37
509
646
Black smoke;
Ditto Whltworth . - -
8-4
42 88
1-79
3^8 1
661
Ditto.
Ditto Willington West -
8-93
43 11
1-3?.
3 65
6-
No record.
Hastings Hartley ....
773
47'46
1-16
891
61
lieary black snokr
Heaton Colliery ....
8 79
46 2
238
629
8-67
Much smolte.
Howard's West Hartley
17
808
49-58
1 24
469
6-93
D^rk smoke.
Ditto Netherton ...
9-68
58*36
922
5^14
7-86
Ditto.
Hoyland Colliery ....
Ditto and Elsecar ...
87
48-98
•.V5
395
4-5
Black smoke.
2
815
4578
•67
412
4-7!
No smoke.
Ince Hall Coal ....
7-72
45-22
1-44
54
6-P5
Very smoky.
Ditto .....
804
45 62
1 08
876
4-84
No record.
Kilnharst Hard ....
7 74
45-77
1-21
8-24
4-4ft
Much black smoke.
Land Engine Coal ...
Lindsay Mine ....
Lord Kosslvn's Coal ...
7-86
48f»9
1-5 1
4-68
6- 111
No record.
7-9
42 86
204
2-8H
4-8R
Ditto.
6'il
42-66
1-67
608
775
Bbck smoke.
Lord Ward^s Steam Coal -
7-6
61-3
1-36
4-37
5 74
Brown, in moderatt
quantity.
Lumley's Steam Coal - . .
LundhUl Hard Coal ...
854
87-4
l-OI
6-63
7-64
No record.
8-84
49 19
1-22
8*92
6-14
Black, In great
quantity.
Ditto Soft ditto ...
8-55
50-42
1-6
8-87
5-47
Ditto ditto.
Lyon's West Hartley ...
8-71
52-73
1-17
4-95
6- 12
Black smoke.
Midgeholme ....
925
44-26
-59
6-16
67fe
No record.
North Country Coal ...
8 16
50-14
1-47
8-03
6-5
Heavy black amoke
North Gawber Steam Coal .
7-71
45 04
•8^
4-59
6-44
No record.
Oaks Colliery - . . .
7-75
4491
-42
6-03
6-46
Heavy smoke.
Orrell Steam Coal ...
8'78
42-61
1-54
6-82
8 37
No record.
Ramsay's Adair's Main
865
431
l-OI
5-.15
6-36
Light brown.
Ravensworth's Hartley
7-77
48 44
]*m
4-79
6-4.
Heavy black smoke
Rochsole's Colliery ...
7-76
46-54
167
2-82
4*49
Light smoke.
Skerrington Coal ....
781
47-6
10:?
3^63
4-66
Much smoke.
Ditto Colliery -
8-69
52-45
1-67
5-73
7-41
Liabt smoke.
Splint Coal . • . . .
7-26
4229
•67
42
4-87
Ditto.
St. Helen's Tees ....
919
6415
•33
478
6*11
Black, in large
quantity.
SUveley Main Coal ...
7G9
41 27
•71
426
4-90
Light smoke.
Strangeways, Colliery, 3.ft. Seam
7-91
48 17
•87
5 28
6-15
Black, in small
quantity.
Walthen House, or New House •
8-62
49 11
-2-8'.
6-07
7-92
No record.
Washington's West Hartley
8-63
4826
291
598
8-89
Black smoke.
Wat her House Steam Coal •
7-84
47-75
2-46
361
6-n
No record.
Wellington Hartley ...
7-84
49-92
1-61
4 0'>
6-6
Black smoke.
Weil wood Colliery ...
7 97
50-25
i-a%
y-M
8 1
Heavy black smoke.
West Hartley ....
809
471»7
1-79
44<;
6 2.^
Heavy smoke.
White6eld Colliery ...
9-49
6-i-l7
•05
4 42
4-47
Little brown smokc
Whltworth Park . . . -
8-79
46-49
-9-2
6-14
607
No record.
Wigan, 4 -feet Seam ...
7-97
45 38
1-64
5-75
739
Ditto.
WombwcU Main - . - .
8-26
44->'9
-81
4 5
5-31
Ditto.
Yate Deep Vein ....
8-26
6in
31
4-47
7-57
Much black smoke
Anthraciti Coal ....
958
35-43
1-48
10-32
11*81
No record.
Ditto ....
6-87
26-64
-18
2-42
2 6
Nearly smokclasi.
Ditto Bonfille's Court
8-36
8119
102
5'%7
6 59
No record.
Ditto KiUgetly .
Ditto Watney's . 1
902
42-68
•64
11-8
11-94
Ditto.
8 87
41-44
1-4R
6-58
8-06
Smokeless.
Cambrian Stbam Fuil . . ' .
832
45'45
117
5-81
6 98
Chilian Coal ....
7-29
38 83
2-8
833
6-13
Light smoke.
tCOKB CONIOLIDATID ...
8-76
19-47
•14
1911
19-25
No record.
Patent Fu»l - . . -
859
4885
ID?
4-21
618
Ditto.
Ditto
911
48 2
2-4
3-86
6-26
Black smoke.
Ditto Captain Cochrane's
Ditto Holland's
401
2200
7-76
32-5
40-26
No record.
7-94
89-51
1-7
63
8-
Light brown.
Ditto Lyon's ...
81)8
474
2-86
4-37
724
No record.
Ditto Temperly's -
Ditto Warlich's - .
8-5
42 45
-99
7-19
8 19
Ditto.
8-7
44 12
•2-4
V'A
1004
Little brown smoke
Ditto ditto ...
9 16
46 47
3-03
6-62
865
No record.
POBT Adblaiob ....
644
82-3
7*42
23 3^
30 77
No smoke.
SIN04P0RB Coal ....
6 97
48 77
•
9^9i»
No record.
St. DoMiKao (Samana)
1-29
10-59
•
18-
18-
Little smoke.
FULLING*
307
FULGUR ATION designates the sudden brightening of the melted gold md silver
in the cupel of the assayer, when the last film of Titreous lead and copper leaves their
surface.
FULLER'S EARTH. {Terre hfouhn, ArgHe, Smeetigue, Fr. ; Walkererde, Germ.)
In geology this term is applied to the clayey deposit which intervenes between the
calcareous strata commonly known as the Bath or Great Oolite, and the Inferior
Oolite. A sandy argillaceous earth is met with in the upper part of the clny in
question, to which the name Fuller's earth was given from its adaptability for fulling
or cleansing cloth, when first woven, from grease and other impurities. The term
thus limited originally to a particular stratum was subsequently applied to the entire
formation by Dr. William Smith in his classification of the British strata, and
has ever since retained its place in geological nomenchiture. The fuller's earth
above mentioned was formerly procured in considerable quantities from the Downs,
to the south of Bath, whence it was sent to the cloth factories of Gloucestershire.
Of late years, however, an artificial substitute has been found in a chemical prepa-
ration, and the demand for the natural production has decreased so far, that little or
none of it is now procured in the West of England. The fuller's earth of Reigate is
found in strata of a much more recent date than those alluded to above, and forms a
part of the Lower Greensand. — See Gbeensand.
From Reigate 12,000 tons of dried fuller's earth are raised annually. There are
two rarieties, called the blue and yellow ; their analyses are respectively —
Biu«.
Alumina --•-•-.is
42
4
2
6
5
Silica
Lime
Magnesia -
Oxide of Iron
Soda
Yellow.
11
44
5
2
10
5
884
The other places from which fuller's earth has been obtained, are — Penenden
Heath, Maidstone, Frome, Lonsdale, Coombe Hay, English Coombe, and Duncom
Hill in Gloucestershire, and at one locality in Bedfordshire. — H. W. B.
FULLING. The art of cleansing, scouring, and pressing woollen manufactures.
The object is to render them stronger and finner. It is called also miilin^, because
the cloths are scoured by a water mill
The principal parts of a fulling mill, are the wheel with its trundle, which gives
motion to the tree or spindle whose teeth communicate that motion to the stampers or
beaters, which fall into troughs, wherein the cloth is put, with the fuller's earth.
William and Ogle introduced in 1825 some new fulling machinery, designed to act
in a similar way to the ordinary stocks, in which cloths are beaten, for the purpose of
washing and thickening them ; but the standard and the bed of the stocks are made
of iron mstead of wood, as heretofore ; and a steam vessel is placed under the bed, for
heating the cloths during the operation of fulling $ whereby their appearance is said
to be greatly improved.
Fig, 884 is a section of the fulling machine or stocks ; a, is a cast-iron pillar, made
hollow for the sake of lightness; 6, is
the bed of the stocks, made also of iron,
and polished smooth, the side of the stock
being removed to ^ow the interior ; c,
is the lever that carries the beater d.
The cloths are to be placed on the bed
b, at bottom, and water allowed to pass
through the stock, when by the repeated
blows of the beater d*, which is raised
and let iall in the usual way, the cloths
are beaten^ and become cleansed and
fulled.
A part of the bed at e is made hollow,
for the purpose of forming a steam box,
into which steam fh>m a boiler is intro-
duced by a pipe with a stop-cock. " Thii
steam heats the bed of the stock, and
greatly facilitates, as well as improves,
the process of cleansing and fulling the
cloths.
The smoothness of the surface of the polished metal, of which the bed of the stock
is constituted, is said to be very much preferable to the roughness of the surface of
▼ood of which ordinary fulling stocks are made, as by these iron stocks less of the nap
z2
308 FULMINATING SILVER.
or felt of the cloth is removed, and its appearance when finished Is very mach sapenor
to cloths failed in ordinary stocks.
In the operation of falling, the cloths are tnmed over on the bed by the Iklling of
the beaters, bat this taming oyer of the cloths irill depend in a great measure opon
the form of the front or breast of the stock. In these improved stocks, therefore,
there is a contrivance by which the form of the front may be varied at pleasure, in
order to sait cloths of different qaalities ; /, is a movable curved plate, constituting
the fW)nt of the stock ; its lower part is a cylindrical rod, extending along the entire
width of the bed, and being fitted into a recess, forms a hinge joint upon which the
curved plate moves ; ^, is a rod attached to the back of the curved plate f^ with a
screw thread upon it ; Uiis rod passes through a nut A, and by turning this nut, the rod is
moved backward or forward, and consequently, the position of the curved plate altered.
The nut A, is a wheel with teeth, taking into two other similar toothed wheels, one
on each side of it, which are likewise the nuts of similar rods jointed to the back of
the curved plate/; by turning the central wheel, therefore, which may be done by a
winch, the other two wheels are tamed also, and the curved plate moved backward or
forward. At the upper part of the plate there are pins passing through curved slota^
which act as guides when the plate is moved.
FULMINATING MERCURY, C*N«Hg«0« + Ag. (dried at 2120). The wcU
known compound used for priming percussion caps. It was analysed many years
ago by Liebig, and subsequently, by Gay-Lussac. Although chemists have long beea
acquainted with the true composition of fulminic acid, and the formula of fulmin-
ating mercury has also been rendered almost certain, no accurate analysis of the
latter compound was made public until 1855, when M. Schischkoff published his cele-
brated paper on the fulminates. It is sing^alar that Liebig and Schischkoff were
independently engaged at the same time in investigating the products of decomposition
af the f alminates. The formula of fulminic acid, and also that of fulminating mercury,
had been deduced fW>m the very accurate analysis of fulminating silver made by Gay-
Lussac and Liebig. A great number of processes for the preparation of fulminating
mercury have been published. The following are the best as regards economy and
certainty.
1. One part of mercury is to be dissolved in 10 parts of nitric acid, sp. gr. 1*4, and
the solution at a temperature of 130^ F. is to be poured into 8*3 parts of alcohol, sp. gr.
0-830. — i>r. lire,
2. One part of mercury is to be dissolved in 12 parts of nitric acid, of sp. gj. 1 *3. To
the solution (as soon as it has cooled to 55^ F.), 8 parts of alcohol, sp. gr. 0*837, are to
be added ; the vessel containing the mixture is to be heated in boiling water until
thick white Aimes begin to form. The whole is then set in a cool place to deposit the
crystals of fulminate. — CremascolL
3. One part of mercury is to be dissolved in 12 parts of nitric acid, sp. gr. 1*340 to
1*345, in a flask capable of holding 18 times the quantity of fluid used. When the
metal is dissolved, the solution is decanted into a second vessel containing 5*7 parts of
alcohol, of 90^ to 92^ (TraUes), then immediately poured back into the first vesseL asd
agitated to promote absorption of the nitrous acid. In five to ten minutes gas babbles
begin to rise, and there is formed at the bottom of the vessel a strongly refracting,
specifically heavier liquid, which must be mixed with the rest by gentle agitation. A
moment then arrives when the liquid becomes black from separation of metallic
mercury, and an extremely violent action is set up, with evolution of a thick white
vapour, and traces of nitrous acid; this action must be moderated by gradually pour-
ing in 5*7 parts more of the same alcohol. The blackening then immMiately dis-
appears, and crystals of fulminating mercury begin to separate. When the fluid has
become cold, all the fulminating mercury is found at the bottom. By this method
not a trace of mercury remains in solution. — Lid>ig,
The fulminate in all these processes is to be collected on filters, washed with dis-
tilled water, and dried. The violent reaction which takes place when the solution of
mercury reacts on the alcohol is essential to the success of the operation.
With regard to the economy of the above methods, it has been found that 1 part
of mercury yields the following proportions of fulminate : —
1st process •-•----- i»30
2nd „ 1-25
Srd„ -- 1*53
C.G.W.
FULMINATING SILVER, (^ Ag^N*0«. This salt corresponds in constitution to
the fulminate of mercury ; it may also be prepared by analogous processes, merely
substituting silver for mercury. Preparation, — 1. 1 part of silver is to be dissolved in
jt4 parts of nitric acid, sp. gr. 1-5, previously mixed with an equal weight of water.
FUR. 809
To tlie aolation ifl to be added alcohol equal in weight to nitric acid. Produce^ \ 5
parts of fulminating silyer. 2. 1 part of silver is to be dissolved in 20 parts of nitric
acid» sp. gr. 1*38. To the solation is to be added 27 parts of alcohol, sp. gr. 0*832.
The mixtore is to be heated to boiling, and, as soon as it shows signs of becoming
turbid, it is to be removed from the fire, and a quantity of alcohol, equal in weight to
the first, is to be poured in. The liquid is now to be allowed to become perfectly cold,
when the fulminate will be found at the bottom of the vessel Produce^ equal to the
silver employed. 8. 1 part of silver is to be dissolved in ten times its weight of nitric
acid, spb gr. 1-36. To the solution is to be added 20 parts of alcohol, sp. gr. 0 83.
The mixture is to be treated as in the second mode of preparation, except that no
more alcohol is to be added. The produce should be in fine crystals. Whichever
mode of preparation be selected, it is absolutely necessary, in order to avoid fearful
accidents, that the following precautions be attended to. The beakers or flasks em-
ployed must be two or three times larger than is required to hold the ingredients, for
if, owing to frothing or boiling over, any of the fluid happened to find its way to the
outside, and dry there, an explosion might ensue. Care must also be taken that the
highly inflanunable vapours given off during the preparation do not come near any
flame. The salt, when formed, must be received on a filter, and well washed with cold
water. It is safer to dry it'spontaneously, or over oil of vitriol, for although it will
endure a heat above that of boUing water before exploding, yet when warm, the slightest
touch with a hard substance is often sufficient to cause a terrible detonation. A spatula
of pasteboard or very thin wood should be employed to transfer it into its receptacle.
Fulminating silver should not be kept in glass vessels, for fear of the salt finding its
way between the cork or stopper, the slightest movement witii a view of opening the
vessel, being then sufficient to cause an accident Small paper boxes are the safest to
keep it in.
Fulminating silver gives a more vi(^ent detonation than the corresponding mercurial
compound. The presence of roughness or granular particles on the substances with
which it may be in contact, assists greatly in causing it to explode.
Although giving so violent an explosion when alone, it may be burnt without
danger when mixed with a large excess of oxide of copper, as in the ordinary process
of organic analysis. It then gives off a mixture of two volumes of carbonic acid, and
one volume of nitrogen. Gay-Lussac and Liebig made an analysis of the salt in this
manner, with the annexed results : *-
Bzpcrimrat.
Calculation.
Carbon • • .
• 7-9
C*
•
- 24
- 80
Nitrogen - - -
- 9-2
N«
.
- 28
- 9-3
Silver - - ^
- 72-2
Ag*
-
- 216
- 72-0
Oxygen ...
- 10-7
O*
-
^ 32
- 10-7
100*0 300 IQO'O
For further remarks on the fulminates, see FvufiNATiNa Mercurt. — C. G. W.
FULMINIC ACID, C^N^H'O*. The acid contained in fuhninating mercury ;
which see.
FUMIGATION is the employment of fumes or vapours to purify articles of ap-
parel, and goods or apartments supposed to be imbued with some infectious or con*
tagious poison or fumes, The vapours of vinegar, the fumes of burning sulphur,
explosion of gunpowder, have been long prescribed and practised, but they have in
all probability little or no efficacy. The diffusion of such powerful agents as chlorine
gas, muriatic acid gas, or nitric acid vapour, should alone be trusted to for the
destruction of morbific effluvia. See Disinfectants.
FUR. (j^oumtf e, Fr ; Pelz, Germ. ) Fur may be strictly distinguished as the short
fine soft air of certain animals, growing thick on the skin, and distioguished from the
hair which is longer and coarser. The term is, however, used sometimes very loosely,
and includes those skins which are covered with hair* Fur is one of the most perfect
non-conductors of heat, and consequently we find the animals of the colder regions of
the earth clothed with this substance, and heoce man has adopted it as the warmest
of clothing.
To the admirable report made by Messrs. J. A. Nicholay and James B. Bevington, on
the furs of the Great Exhibition, we are mainly indebted for the following particulars.
Ths Russian Sabls (^Muatda zihetlina). In the reign of Henry VIIL, by a law
to regulate the expenses of different classes, and to distinguish them by peculiarity of
costume, the use of sable was confined to the nobility above the rank of viscount. It
is stated that 25,000 skins are annually collected in the Russian territories. The fur
IS brown, with some grey spots on the head ; the darker varieties are the most valuable,
a single skin of a fine dark colour being sold for as much as nine pounds, though the
X 3
810 FUR.
average Talae does not exceed two or three. The Rusian sable is sometimes con-
founded with the Hudson's Baj sable, but to the furrier the former is easily dis-
tinguishable from the length and fullness, as well as the darker coloar, of the far.
HUD80N*8 Bat Sable {Mustela Canadauu). As the natural colour of this skin is
much lighter than the prerailing taste, it is the practice to dye many of them a
darker colour, and the furs thus treated are scarcely inferior to the Russian or true
sable. Not less than 120,000 skins are annually imported into this country.
Pine Mabten or Baum (^Mustda aUetum), The animals producing this skin are
found in extensiye forests in the north of Europe. The skins are distinguished from
the stone martin by the yellow colour of the throne. These skins are dyed to imitate
real sable.
Stone Mabten {Mutteia aaxonm). This is frequently called French sable, fhmi
the fact that the French furriers excel in dyeing this skin. The stone marten is dis-
tributed through most European countries. The under fur is a bluish white, with the
top hairs a £irk brown, the throat being generally a pure white, by which it is
distinguished.
FiSHEB. These skins are larger than the sables, and the fur is longer and fuller;
about 1 1,000 of these skins are annually brought from America. The tail, which is
long, round, and gradually tapering to a point, was formerly used as the common
ornament to a national cap worn by the Jew merchants of Poland.
Mink {Mugtda vimm\ There were 245,000 skins of this little animal brooght to
this country in 1850. The fur resembles sable in colour, but is considerably shorter
and more glossy.
Ebmine (Miutela erminea). This animal is similar in form and habit to the
common weasel of this country, but in Siberia, Russia, and Norway, fh>m whence the
skins are imported ; the little animal during winter becomes as white as the snowy
regions it inhabits, and is esteemed the whitest fur known, though in summer its
dress is a dingy brown. The tail of the skin, of which the lower half is jet black is
usually introduced as an ornament to the purely white fur. In Edward IIL*s reign,
the use of ermine was restricted to the royal family.
Fitch or Polecat {Hfustela putorius), produced throughout Europe and in our
own country. This animal has a soft black fur with a rich yellow ground. The
natural smell of this fur is unpleasant and difficult to OYcrcome.
NoBTH American Skunk (^Mephitis Americana). These skins are imported by
the Hudson's Bay Company. The animal from which it is obtained is alhed to the
polecat of Europe. The fur is a soft black, with two white stripes running firom the
head to the tail This fur is not much used in this country.
Kolinsky {Muttela Siberica). The Tartar sable, which is of a bright yellow
colour. It is sometimes used in its natural state, but is more frequently dyed brown
to imitate other sable, to which it bears a strong resemblance. It is remarkable for
the uniformity of its colour, baring no spot or diiSerence of shade in any part of the
body. The tail which is of the same colour, is exclusively used for the best artist's
pencils.
Musk Rat or Musquash (Fiber zibetfuciti), an inhabitant of the swamps and
rivers of America. About a million skins are brought to this country annually.
The fur resembles that of the bearer, and was used by hat manufhcturers. The skins
are also dyed by the furrier, and manufactured into many cheap and useful articles.
Ndtria or CoTPON {Myopotamus ccypus). This animal is larger than, but some-
what similar to, the musquash ; it inhabits the banks of rirers in Buenos Ay res and
Chili. Bat few of these skins are now imported.
Hamsteb {Cricetus vulgaris^ a native of Germany, where not less than 100,000
skins are annually collected. It has a poor, short, and coarse Air, which is almost
excluairely used for cloak linings by the Greeks. The colour of the back is a reddish
brown, the beUy black, with a few light spots.
Perwitzkt. The skin of this animal is marked like tortoise shell ; it is brought
fVom |he southern extremities of Asiatic Russia. It is chiefly used by the Russians
for cloak lining.
Beaveb (Castor Americanus). This beautiful fur is sometimes used for articles of
dress. In order to prepare the skin for this appropriation, the coarse hairs are re-
moved, and the surface cut by a very ingenious machine, somewhat similar to that
used in dressing cloth. The skin thus prepared has a beautiful appearance, not
unlike the costly South Sea otter, and has the advantage of durability and lightness.
Otteb (Xi/tra vulgaris, Lutra Canadensis), Of the British otter about 500 skins
are collected annually < The large quantity used by the Russians and Chinese is
derived principally ftom North America.
Sea Otteb (Enhydra marina). The sea otter has a very thick, soft, woolly for,
and is most highly prized by the Russians and Chinese, to whom most of the skins
FUE.
811
are exported. The animal is found in the North Pacific from Kamtschatka to the
Yellow Sea, on the Asiatic coasts, and from Alaska to California on the American coasts.
Sbal (Pftoea). There are numerous varieties of these animals, which are found on
tbe western coasts of these islands, and in immense numbers on the shores of Labrador,
Greenland, and Newfonndlaod. The greater portion of the skins imported are
tanned and enamelled with black Tarnish for ladies' shoes ; other descriptions are
well adapted for fur. Before they can be used as a fur, it is necessary to remove the
▼ery coarse hairs which cover a beautifully fine and silky fur. By shaving the felt
to half its natural substance, the roots of the coarse hairs are cut through, and they
easily fall out, but the same effect is produced by the natural process of fermentation,
which ensues when the skins are properly prepared and allowed to remain together.
This fur is rarely used in its natural state, but is dyed a deep Vandyke brown, when it
has the appearance of the richest velvet.
Tbe skins of the fox, the wolverine (^Gulo Iiucms\ the bear, the hare, and the rabbit,
•earcely require notice.
The Squibbbl, especially the Siberian squirrel, is much sought for. It is said that
15,000,000 of these skins are annually collected in Russia, and of these, 3,000,000 are
sent to this conntrr.
CHIKCHII.LA (^dhinchiUa lanigera). There are two varieties of Chinchilla, the
produce of South America. Our chief supply is fh>m Buenos Ay res and Arica.
The skins from the former locality are of a silvery grey. Those from Arica are the
darkest and best coloured skins.
Raocook {Proeycn totor), this far is used for lining coats.
Cat (^Fdix domesticud). In Holland, the cat is bred for its fur ; it is fed on fish and
carefully tended until the fur arrives at perfection.
Canada Ltvx {Felix Canadensis), This fur is not much used in this country,
bat it is prepared and exported for the American market
Number of Skins and Furs imported in the ifears 1858 to 1857.
Skins : ~
18S3.
18M.
1855.
1S56.
1857.
No.
No.
No.
No.
No.
Sheep and lamb
3,372,855
3,410,161
1,806,001
3,084,683
3,685,633
Goat -
-
661,084
911,925
503,918
1,218,548
1,158,277
Kid -
.
887,426
726,004
695,859
4.53,810
402,600
Seal •
•
850,550
661,552
601,002
681,234
803,438
Furs: —
Marten -
•
134,671
193,418
222,153
206,777
157,319
Mink -
■■ m
184,529
200,205
167,981
113,046
146,640
Raccoon''
.
475,858
505,445
394,655
498,121
492,159
All other sldns and furs
-♦
286,126
273,764
448,049
438,379
Total Value of Skins and Furs imported in the years 1854 to 1857.
Skins and fhrs - . • -
1854.
1859.
1856.
1857.
£
1,017,453
£
941,855
£
1,436,969
£
1,422,974
Number of Skins and Furs exported in the years 1853 to 1857.
Skins : —
1863.
1854.
1855.
1866.
1857.
No.
Na
. -No.
No.
No.
Sheep and lamb
36,368
334,622
221,759
317,391
271,825
Goat - - •
240,945
285,548
128,659
265,438
399,140
Kid - - -
43,749
25,347
17,693
4,894
19,841
Seal - . -
12,163
18,011
1,995
' 3,695
5,721
Furs : —
Marten - . -
29,677
24,253
29,476
46,367
89,038
Mink .
74,309
61,557
78,744
46,749
84.731 .
Raccoon
483,893
507,047
523,928
380,870
486,628
All other skins and furs
« »
115,166
141,415
225,904
228,620 ;
• Not awertnined preTlously to the year 1854.
X 4
312
FUR
Total Value of Sking and Fur$ exported in die yeare 1854 to 1857.
Skins and fhn - • .
1854.
1855.
1856.
1867.
£
847,549
£
270,807
£
396,561
£
489,784
Quantities and Value of Skins and Furs exported in the year 1857.
Skins:-—
Beaver - - -
Goat ...
Fox- - . -
Musquash
Raccoon • . -
Sheep and lambs
Qiuntitiet.
Value.
British
Produce.
Foreign
and Co-
lonUl Pro-
duce.
Total.
Britfth
Produce.
Foreign
and Co-
loDial Pro-
duce.
Total.
No.
102,503
584,705
l,613i761
No.
87,440
399,140
80,582
448,240
485,528
271,825
Na
87,440
501,643
80,582
1,032,945
485,528
1,885,586
1 4t
9,309
35,872
78,682
41,534
41,852
66,144
23,345
91,036
16,929
41,534
51,161
66,144
59,217
91,036
95,549
Quantities and Value of Skins exported in the year
1857.
1
Skins: —
QuantlUei.
Computod
Real Value.
Skins :-^
Quantities.
Compated
Real Value.
No.
t
No.
€
Bear - - -
7,917
14,844
Marten
89,038
72,343
Cat - -
4,570
1,066
„ tails -
1,830
46
Chinchilla -
24,793
1,679
Mink
84,781
33,559
Coney
18,016
375
Nutria
36,436
2,012
Deer - - -
43,607
8,684
Otter . - -
10,346
15,390
Dog -
144
1
Peite -
560
5
Dogfish
397
17
Sable-
124
320
Elk - - -
28
21
„ t&ils
270
27
Ermine
920
103
Seal - . -
5,721
2,336
Fisher
8.112
12,337
Squirrel -
550
7
Fitch -
3,605
496
„ tails -
• ••
502
Hare-
40.835
936
Swan *
250
82
Kid .
19,841
3,109
Tiger
7
12
Kolinsky -
1,503
263
Wolf-
5,715
2,715
Leopard - •
29
43
Wolverines
658
493
Lion
22
22
Unenumerated •
...
17,663
Lynx
27,251
17,486
The importance of the trade in furs and skins will be rendered evident from the
preceding accounts of the Imports and Exports. It would have been desirable to
have separated the furs, strictly so called, from the skins, but this has not been found
practicable with anything like accuracy; the returns are therefore given under the
heads adopted by the Customs.
Furs are subject to ixgury by several species of moths, whose instinct leads them to
deposit their eggs at the roots of the fine hair of animals.
Linnaeus mentions five species that prey upon cloth and furs, of which Tinea peBi'
oneUa^ T. vestioneUa and T, tapelzella are the most destructive. No sooner is the
w^orm hatched^ than it eats its path through the fur, and continues increasingly
destructive until it arrives at its full growth, and forms itself a silken covering, from
which, in a short time, it again emerges a perfect moth.
Another cause of the decay of fur is, the moisture to which they are frequently
exposed ; the delicate structure of the fine under fur cannot be preserved when any
dampness is allowed to remain in the skin. This fact is well known to the leather
mmnfacturer, who, having wetted his skins, allows them to remain in a damp cellar
FUSEL OIL. 813
for a few days, for the pnrpose of remoying the hair which is palled oat with the
greatest fhcility, after remainiDg only one week in a moist condition. It follows firom
these ohservations, that to preserre the fur it is necessary to keep them dry, and to
protect them from moths ; if exposed to rain or damp, they most be dried at a moderate
distance from the fire; and when pat by for the saouner should be combed and
beaten with a small cane, and rery carefully secured in a dry brown paper or box,
into which moths cannot enter. During the summer they should be examined once
a month to be again beaten and aired, if the situation in which they hare been placed
be at all damp. With these precautions, the most Taloable furs may be preserred un-
iijnred for many T^^ars.
FURNACE. The rarioos descriptions of fomaces employed in the different
metallargical processes will be found described in the articles deYoted to the metals.
See Brass, Coppbr, &c &c., and Metallubgt.
FUR.SKIN DRESSING. Fur-skins are usually dressed by placing them m their
dried state in closed tubs with a little salt butter, where they undergo a treading
operation with men*s feet until they are sufficiently soft, and bend easily. The skins
if large are sewn up, the fur being turned inwards j but if small skins, such as ermine,
are being dressed, they require no sewing. This sewing is preparatory to the greasing
with batter or lard, and is intended to protect the for from the grease, and to promote
the softening in the succeeding treading operation. The skins are next wetted, and
their flesh is removed ; or they are fleshed. See Cubbtino. They are again sub-
jected to treading in tubs containing sawdust, that from mahogany being preferred ;
and afterwards in tubs containing plaster of Paris, or whitening, sprinkled between
the skins. The main object of this is to remove the grease which has been used in
the previous processes. They are then beaten with a stick, and combed ; when the
dressing is completed. H. Pierre Tbirion proposed to soften the skins, not by tread-
ing, but by beating stocks, of a construction like the fulling milL They are next
sewn up, and again filled in a strong vessel, where they are forced upwards by the
beaters, turned over and over, and thus speedily softened. They are now fleshed, and
then returned to the beating stocks, and mahogany or other sawdust is sprinkled upon
the for, before the beating is renewed. They are next placed in a heated bairel,
famished within with radisd pins for taming the goods over and over, in order that
they may be acted npon by varioos dry substances, which are thrown into the barrel,
and absorb the fat from the skins. Through the hollow shaft of the barrel steam is
introduced, which heats the skins, softening the fat, which is then absorbed by sand,
flour, or any other desiccative powder. It is proper to take the skins out of the
barrel from time to time, to comb them. Such as have been sufficiently acted upon
may then be set aside. They are lastly freed from the dust by being subjected to a
grated cylinder in a state of rotation, and then combed by hand.
FUSEL OIL. During the rectification of com or grape spirits there is always
separated a fiery fcetid oil of nauseous odour and taste. It is this substance which is
the cause of the unpleasant effects which are produced upon most persons by even a
small qaantity of insufficiently rectified whiskey or brandy. Any spirit which pro-
duces milkiness on the addition of four or five tmies its volume of water may be sus*
pected to contain it. By repeated rectification every trace may be removed.
Fusel oil invariably consists of one or more homologues of the vinic alcohol (OH*0^,
mixed with variable quantities of the latter substance and water. The nature of fusel
oil varies much with the source fVom whence it is obtained. That which is ordinarily
sold in this country for the purpose of yielding pear essence consists mainly of the
amy lie alcohol (C'*H"0'), mixed with from one-fourth to one-fifth of spirit of wine.
llie progress of organic chemistry has been greatly assisted by the researches which
have been made upon fusel oil, almost all the amylic compounds hitherto obtained
having been directly or indirectly obtained Arom it
To obtun fusel oil in a state of purity it is necessary, in the first place, to rectify
it IHctionally. By this means it will be found that much alcohol can be removed at
once. If a great quantity of water and very little vinic alcohol be present, the simplest
mode of purification is to shake it with water, by which means common alcohol is
removed in solution, while the amylic alcohol, owing to its comparative insolubility*
may be easily separated by the tap-funnel. After drying over chloride of calcium, it
is to be again rectified once or twice, only that portion distilling at about 269*6^ Fahr.
(132<^ Cent) being received. The product of this operation is pure amylic alcohol,
from which an immense number of derivations of the amylic series can be obtained.
By treatment with sulphuric acid and bichromate of potash it Is converted into vale-
rianic acid. In this manner all the valerianic acid, now so much employed in medi-
cine is prepared. By distilling amylic alcohol with sulphuric acid and acetate of
potash, we obtain the acetiite of amyle, commercially known as jargonelle pear essence.
The foreign fusel oils obtained fh)m the grape marc contain several homologues
314
FUSEL OIL.
liigher and lower in the series than the amylic alcohol. In faet, it wonld appear thai
daring the fermentation of grapes there are formed, not only alcohols, bat ethers and
acids.
M. Chancel, bj repeatedly rectifying the dehydrated and more volatile portions of
the residaes of the distillation of grape marc alcohol, sncceeded in isolating a fluid
boiling at 205^ Fahr. This proved to be pore propionic alcohol. M. Wnrtz has also
been able to obtain the butylic alcohol by rectifying certain specimens of potato oiL
All fusel oils are not so complex. The author of this article has repeatedly examined
specimens of English and Scotch fusel oil, irhich did not contain anything save the
ethylic and amylic alcohols, accompanied by small portions of the acids, -which are
procured by their oxidation. M. Chancel has given the following equations, which
explain the manner in which saccharine matters break up into homologoos alcohols
under the influence of ferments. I have reduced the unitary notation employed by
him into the ordinary formulse used in this country, in order to render the relations
as clear as possible to the reader.
2C"H"0" « 8C0» + 4C«H«0«.
Glacose
2C"H"0'*
2C»H»0"
2C»H"0"
AlcohoL
8C0« + C*H«0» + 2C«H"0« + 2HO.
Propionic alcohol.
SCO* + 2C«H>»0' + 4H0.
Butylic alcohoL
8C0» + C«HK)« + C"H'K)« + 4HO.
Amylic alcohol.
M. Chancel appears to consider the last equation as indicating the necessity of pro-
pionic alcohol being id ways formed wherever amylic alcohol is generated; but this is
not in accordance with the results of those chemists who have examined crude amy lie
alcohol repeatedly for propionic alcohol, but without finding any. The formation of
these interesting homologues appears therefore to depend upon special circumstaooes
connected with the fermentation.
The caproic alcohol is also contained in certain varieties of fusel oiL
In order to assist those who may wish to examine the fluid alluded to, the following
table of the physical properties of the alcohols up as high as the caproic has been
inserted : —
Table of the Physical Properties of some Homologous Alcohols found in Fus^ OSe.
Name.
OiMCfTcn*
Forarala.
BoUfng Point
Specific Gravity.
Vapour Dmdty.
Espoimmta.
•Cakolatka.
MethTlic
Ethylic -
Propionic -
Butylic
Ainylic
Caproic
Dumas and Pellgot
Gay-Lusaac -
Chancel
Wurt« -
Balard and Duma«
Paget - - -
C«H<0«
C<H60«
CBH^O*
C8H»oo«
C10H12OS
CI3H1402
1520
17'/>
S05O
23>|0
270O
304O
0-7980 at 680
0-7938 at 60^
• • •
0-8184 at SQO
0 8330 at 320
1120
1-613
S'OaO
3147
3-530
M07«
l-ikSlS
«o7eo
26304
3-0448
Fusel oil, in addition to these homologous alcohols, contains several fatty acids.
The following list contains the acids found in fusel oil, with the name of the obsenrer.
Name of Acid.
Formula.
Obfenrer.
Formic - - - -
C«H»0<
Wetherill
Acetic - - - -
c*w(y
Kent
Valerianic - - -
C'«H'«0«
Kent
Caproic- ...
C'«H'«0*
Wetherill
(Enanthylic - - -
C*H"0»
Mulder, WetheriU
Caprylic . - -
CWH'»0»
Wetherill
Caprie - - - -
C»H«0«
Rowney
Margaric • - .
C"'II«0*
Kolbe
FUSTIAN, 815
Fusel oil has been patented as a solvent for qnioine, bat its odonr, and more espe-
cially that produced by its oxidation, so persistently adheres to anything irith iirhich
it has been in contact, that great care is requisite in the purification* It is remark-
able that at the first instant of smelling most speeimens of fusd oil, the odour is not
unpleasant, but in a very few seconds it becomes exceedingly repaJsiye, and pro-
Tokes coughing. — C. G. W.
FUSES. See Safety Foses.
FUSIBILITT. That property by which solids assume the fluid state under the
influence of heat With a few exceptions, such as carbon and some organic bodies,
all substances appear capable of assuming the fluid state. Although we do not ap-
pear to hare actually fused charcoal by means of the voltaic battery, the diamond has
been fused and converted from a crystalline gem into a mass of opaque coke.
Thenard has thus grouped the metals: —
1. Fusible below a red heat : — Mercury, potassium, sodium, tin, Insmuth, lead, ieUu*
rium, arsenic^ zinc, antimony, cadnium.
2. Infusible below a red heat : — SUver, copper, gcid, ecbcdt, iron, manganese, nichd,
pattadium, molybdenum, uranium, tungsten, chromium, titanium, cerium, osmium, iridium,
rhodium, platinum, columbium,
Pouillet has, in his admirable treatise on heat, given the following table of the
fusing points of various substances : —
Mamei.
Centigrade.
Mercury -
-
•
•
—39
Oil of turpentine
-
-
—10
Ice -
-
.
•
0
Tallow -
•
«
.
83 to 38
Acetic acid
.
«
•
45
Spermaceti
•
-
-
49
Stearine -
-
-
.
49 to 43
Margaric acid
.
•
•
55 to 60
Unbleached wax
m
*
6t
White wax
.
.
68
Stearic acid
»
•
70
Phosphorus
-
•
43
Potassium
.
.
58
Sodium
.
.
90
Iodine
.
•
107
Sulphur -
••
.
114
Tin
.
.
230
Names.
CcDtlgrade.
Bismuth -
-
-
203
Lead
■>
820
Zinc
.
860
Antimony
••
432
Bronse -
-
900
Silver, very pure
«
1000
Standard gold
-
1180
Vwy fine gold -
-
1250
White cast iron, v^ry fusible 1050
White cast iron, second fusion 1200
Grey cast iron, very fusible 1100
Grey cast iron, second fusion -1200
Manganesed cast iron - 1250
The more ftisible steels - 1300
The less fusible steels - 1400
Soft iron (French) - - 1500
English hammered iron - 1600
FUSIBLE METAL. See Aixot.
This ailoy owes its peculiar property of melting at a 'Comparatively low tempe-
rature to the presence of bismuth.
8 parts of bismuth, 5 of lead, 3 of tin - melt at 212^ F.
3 dOb 1 do. 1 do. - do. 201^ F.
5 do. 8 do. 2 do. - do. 199^ F.
8 do. 5 do. 4 of tin, and 1 of type metal is an alloy
much used on the continent for producing casts of metals by the cliches process. A
mixture of bismuth, lead, tin, and antimony is used in this country for obtaining
copies fh>m wood blocks. Mr. Cowper used 1 of bismuth and 3 of tin to make the
alloy most suitable for rose engine and eccentric turned pattern, to be printed fh>m
after the manner of letter press.
The soft solders used by pewterers consist of tin, lead, and bismuth in various
proportions ; indeed, bismuth enters to a greater or a less extent into all the soft
solders.
Fusible metal has also been employed as a sort of safety valve for steam boilers.
By adjusting the proportions of the above named metals, an alloy can be made which
will melt at any required temperature ; therefore, when the boiler rose to this tem-
perature, the metal plug gave way and the steam escaped.
FUSTIAN, is a species of coarse thick tweeled cotton, and is generally dyed of an
olive, leaden, or other dark' colour. Besides the common fustian, which is known by
the name of pillow (probably pilaw), the cotton stuffs called corduroy, velveret. vel-
veteen, thickset, used for men's wearing apparel, belong to the same fabric. The
commonest kind is merely a tweel of four, or sometimes five leaves, of a very dose
stout texture, and very narrow, seldom exceeding 17 or 18 inches in breadth. It is
cut from the loom in half pieces, or ends as they are usually termed, about 35 yards
316
FUSTIAN.
long, and after undergoing the sabeeqnent operations of dyeing, dresnng, and folding;
is x^ady for the market
The draught and cording of common fiutian is very simple, heing generally a re-
gular or unbroken tweel of four or five leaves. Below are examples of a few different
kinds, selected tcom those most general in Lancashire.
The number of leaves of heddles are represented by the lines across the paper, and
the cording by the ciphers in the little squares, those which raise erery leaf being
distinguished by these marks, and those which sink them left blank, as more partiea-
larly explained in the article Textile FABRia
When the material is silk, it is called veWet, when cotton^ Yelveteen. A oommoo
tweeled cloth, when composed of silk is called satin ; when of cotton, fustian or jean ^
of woollen, plaiding, serge, or kerseymere.
Ko. 1. — Pillow Fustian.
Na 2. — Phun Velveret
0| 1 1 4
I0| 1 a
ft 1
6
9
9
1 |0| 1 1 1
|0| 1 1 1 1
101 i lOIOI
5
0
a
1
1 |0| 6 a
S
9
s
1 1 10 5 1
4
9
i 1 1 |0| 1
6
4
2 4 3 1
i 6
5
3 1
' Of the above, each contains four leaves of heddles or .healds : that represented by
No. 1 is wrought by four treddles, and that which is distinguished by No. 2, by five ;
the succession of inserting the threads of warp into the heddles will be discovered by
the figures between the lines, anid tbe order in which the treddles are to be successively
press^ down by the figures below.
No. 3.— Double Jean.
No. 4.— Plain Thicksett.
|0| 1 lot 1
9
101 1 1 1
8
101 tO| 1 3
9
loioio 1
6 4
1 |0|0| 3
9
1 1 10 1
A 2
1 101 10 4
9
0| 1 10 OJ
1 3 1
4 3 8 1
4 6 2 3
5
These, like the former, arc wrought with leaves. No. 3 requires four, and Na 4
five treddles. The succession of inserting the threads of warp, and of working the
treddles, are marked by the respective numbers between and under the lines, as in the
former example. Both are fabrics of cloth in very general use and estimation as low
priced articles.
No. 5.— Best Thicksett
No. 6 — Velvet Tuft
I lOjot
10
8 I
I I0| I I I 5 8 1
I
I I I0|
I lo|oi |"T
|oi I |oioT
I 01 i I I
I ioioi I r
6 4
I I I |0| I
6 4 2 8 1
6
6 4 2 3 1
These are further specimens of what may be, and is, executed with four leaves, and
in both examples five treddles are used, With two other specimens we shall conclude
our examples of this description of work, and shall then add a very few specimens of
the more extensive kinds.
No. 7.— Cord and Velveret.
I |0| I I I
I IOIOI I I 5
I 0 I I I U I U|6
I I I |0M
4 2 3 1
2 9
6
T
6 5
No. 8.— Thicksett Cord.
i_9 \±\ J__ll.m
9 I ioi I I r
I I I ill
I iu|0| I I
5 4 3 2 1
10 8 6
In these the succession of drawing and working are marked like the former. The
next are examples of patterns wrought with six leaves. No. 9 has eight, and No. 10
five heddles.
FUSTIAN.
Ko. 9.— DonUe Corduroy. No. 10.— Qeiioa Thickiett.
Qneeu'a V«lvel«etu.
No. 13.— Plun VelTete«il. No. 14.— Oenoft VelTeteen.
The (dditioiul Tuictiei of figure which might be fniea are iliooat eniJIe««, hM the
limiu of thii article vill not admit » f\irther delaiL Those already given are the arti-
elea Id moat gener&l ate. The Tnrietiea of fkocf miy he ladalged to great extent, but
it ii muTersaily fonnd, that the moat atmple pattemi in ever}- department of oraamental
ireaTing, are thoae which attract attention and commaad purchaaera. Weahall there-
fbre only add an example of kiog'a cord, or corduroy, and of Dutch cord, with one of
Genoa and one of eonuncm Telret, to aliov the peculiaritiea.
No. 19.— King-a Cord. No. 16.— Dutch Cord.
Ho. 17.— Oenoa Vdret— No. 18.— Plain Velvet.
818 FUSTIC.
Preparatory to its being cut, the £loth is spread evenly upon a table aboat six feet
long, apon each end of which a roller mounted vith a ratchet-wheel is fixed ; the one
to give o£P, and the other to wind up the piece, in the above six-feet lengths.
The knife is a steel rod about two feet long, and three-eighths of an inch square,
having a square handle at the one end ; the other end is tapered away to a blade, as
thin as paper. To prevent this point from turning downwards and injuring the cloth,
its under side is covered by a guide which serves to stiffen it, as well as to prevent iu
lower edge from cutting the fustian.
The operative (male or female) grasps the handle in the right hand, and insinuating
the projecting point of the guide under the weft, pushes the knife smartly forward
though the whole length of six feet, with a certain dexterous movement of the shoulder
and right side, balancing the body meanwhile, like a fencer, upon the left foot. Tlus
process is repeated upon every adhesive line of the weft
Thb next process to which fustians are exposed is steeping in hot water, to take oat
the dressing paste. They are then dried, reeled, and brushed by a machine, &e.
From twenty to thirty pieces, each eighty yards long, may be brushed in an hour.
The breadth of the cloth is twenty inches. The maceration is performed by immers-
ing the bundled pieces in tanks of water, heated by waste steam ; and the washing by
means of a reel or winch, kept revolving rapidly under the action of a stream of coM
water, for an hour or longer.
After being thus ripped up, it is taken to tin brushing or teazling machine, to make
it shaggy.
This consists of a series of wooden rollers, turning freely upon iron axles, and
covered with tin-plate, rough with the burs of punched holes ; and blocks of wood,
whose concave under surfaces are covered with card-cloth or card-brushes, and which
are made to traverse backwards and forwards in the direction of the axes of the re-
volving rollers, during the passage of the cloth over them.
After they are brushed in the machine, the goods are singed by passing their cut
surface over a cylinder of iron, laid in a horisontal direction, and kept red hot by a
flue. They are now brushed again by the machine, and once more passed over the
singeing surface. The brushing and singeing are repeated a third or even occa-
sionally a fourth time, till the cord acquires a smooth polished appearance.
The goods are next steeped, washed, and bleached by immersion in solution t^
chloride of lime. They are then dyed by appropriate chemical means. After which
they are padded (imbued by the padding machine of the calico printers) with a solu-
fiition of glue, and passed over steam cyUnders to stiffen them.
Smooth fustians, when cropped or shorn before dyeing, are called moleskins ; but
when shorn after being dyed, are called bcverteen ; they are both tweeled fabrics.
Cantoon is a fustian with a fine cord visible upon the one side, and a satiny surface of
yams running at right angles to the cords upon the other side. The satiny side is
sometimes smoothed by singeing. The stuff is strong, and has a very fine aspect.
FUSTIC, or Yellow Wood. {BoisjauM, Fr.; Gelbhob, Germ.) The old fustic
of the English dyer. It is the wood of the Momu tinctoria. It is light, not hard,
and pale yellow with orange veins ; it contains two colouring matters, one resinous,
and another soluble in water. Chevreul has given the name of morin to the colour-
ing matter obtained from fustic. It is procured by boiling ground fustic in distilled
water, passing the decoction rapidly through a filter, and allowing the liquid to stand
for several days, when the colouring matter (morin) is precipitated.
The decoctions of fustic in water are brightened by the addition of a little glue, and
still more so by curdled milk. This wood is rich in colour, and imparts permanent
dyes to woollen stuffs, when aided by proper mordants. It unites well with the blue
of the indigo vat, and Saxon blue, in producing green of various shades. Alum,
tartar, and solution of tin, render its colour more vivid ; sea salt and sulphate of iron
deepen its hue. From 5 to 6 parts of old fustic are sufficient to give a lemon colour
to 16 parts of cloth. This wood is often employed with sulphate of iron in producing
olive and brownish tints, which agree well with its dull yellow. For the same reason
it is much used for dark greens.
The bichromates of potash and of lead, have nearly superseded the use of fustic,
but still, it is employed for producing some green in cotton yam, and in light cotton
fabrics, as gauzes and muslins.
FUSTIC, Youn^. CFustet, Fr.) The wood of the Mua cofinies, a shrub which
grows principally in the south of France and in Italy, called also Venetian mmacA.
This wood contains a large quantity of yellow colouring matter, named fusteric.
This colouring matter has a strong attraction for oxygen, which affects its use as a
dye, rendering it very fugitive. It is rarely used alone, but as an assifltant to strike
some particular tint.
GALLIPOU OIL. 319
G.
GABRONITE, is a yellowish stony sabstance, of a greasy lustre and sp. gr. «
2'74 ; affording no water by calcination ; fusible at the blowpipe into an opaque glass;
soluble in mariatic acid ; solution affords hardly any precipitate by oxalate of ammonia.
This mineral is distinguished by the large quantity of soda which it contains ; its con-
stituents being, silica, 54; alumina, 34 ; soda, 17 '25; magnesia, 1'5; oxide of iron,
1 '25 ; water 2. It is most probably a yariety of Scapolite.
GAD. A miner's tool ; a pointed wedge haying its sides of a parabolic figure.
GADID^. The cod-fish fiunily. Beyond the yalue of the cod-fish as an article
of food, the cod liyer oil is now an important manufacture. See Cod.
G ADOLINITE ; called also Yttrite and Ttterb^te ; is a mineral of a black/brown-
ish, or yellowish colour, granular, or compactly vitreons, and conchoidal fincture ; of
sp. gr. 41) to 4*5, readily scratching glass; at the blowpipe it forms an opaque
glass, sometimes with intumescence, but does not ftise into a bead. It affords, with
acids, a solution that lets fall, with caustic soda, a precipitate partly resoluble in
carbonate of ammonia. It is remarkable for containing from 45 to 55 per cent of the
earth yttria: its remaining constituents being silica, 25*8 ; oxide of cerium, 17*92 ;
oxide of iron, 11*43. This mineral b yery rare, is found in the neighbourhood of
Fahlun and Ttterby, in Sweden; also at Disko, in Greenland; in trap, near Galway;
in granite, in Ceylon ; and in the south of Norway. Its peculiar constituent was dis-
Goyered by Professor Gadolin, after whom it is named.
GALACTOHETER, or LACTOMETER, is an instrument to ascertain the qua-
lity of milk ; an article often sophisticated in yarions ways. Fresh milk, rich in cream,
has a less specific grayity than the same milk after it has been skimmed ; and milk
diluted with water becomes proportionally lighter. Hence, when our purpose is to
determine the quantity of cream, the galactometer may consist merely of a long gra-
duated glass tube standing upright upon a sole. Haying filled 100 measures with the
recent milk, we shall see, by the measures of cream thrown up, its yalue in this respect.
A delicate long-ranged glass hydrometer, graduated from rooo up to 1 060 affords
the most conyenient means of detecting the degree of watery dilution, proyided the
absence of thickening materials has been preylonsly ascertained by filtration. Good
fresh milk indicates from 1*030 to 1*032; when the cream is remoyed, 1*035 to 1*037.
When its density is less than 1 *028, we may infer it has been thinned with water.
GALBANUM is a g^m-resin, which occurs sometimes in yellow shining tears,
easily agglutinated ; of a strong durable smell; an acrid and bitter taste: at other
times in lamps. It exudes either spontaneously or from incisions made into the stem
of the buboH galbanum^ a plant of the fiimily of wnbellifera, which grows in AfHca,
particularly in Ethiopia. It contains 67 of resin; 19*3 of gum; 6*4 of yolatile oil
and water; 7*5 of woody fibres and other impurities ; with traces of acid malate of
lime.
GALENA (Plomb gul/ure, Fr. ; Bleiglanz, Germ.) is a sulphide (sulphuret) of
lead. It is of a lead-grey colour, crystallises in the cubical system, and is susceptible
of cleayages parallel to the faces of the cube ; sp. gr. 7*7592 ; cannot be cut ; fusible
at the blowpipe with exhalation of sulphureous yapours ; is easily reduced to metallic
lead. Nitric acid first dissolyes it, and then throws down sulphate of lead in a white
precipitate ; the solution affording with plates of zinc bWiant laminse of lead (arbor
Saturni). It consists of sulphur 13 ; lead 85 ; with a little iron, and generally a small
quantity of siWer. This is the richest ore of lead, and it occurs in almost eyery geo-
logical formation, in yeins, in masses, or in beds. Galena in powder, called Alquifoux,
is employed as a glaze for coarse stoneware. See Lead. <
GALIPOT, is a name of a white semi-solid yiscid resin, found on fir-trees ; or an
inferior sort of turpentine, ]>oor in oiL
GALL OF ANIMAL& See Ox Gall.
GALL OF GLASS, called also SANDIVER, is the neutral salt skimmed off the
surface of melted crown glass ; which, if allowed to remain too long, is apt to be re-
absorbed in part, and to iignre the quality of the metal, as the workmen call it See
Glass.
GALL ATES ; salts consisting^ of gallic acid combined with bases ; the most im-
portant being that with oxide of iron, constituting a principal part of the black dye.
GALLERY, in mining, in some districts, an underground horizontal excayation*
GALLIARD, a north of England term for a hard, smooth, flinty grit
GALLIC ACID is the peculiar acid extracted ft*om gall-nuts. See Gall-nuts.
G ALLIPOLI OIL is a coarse oliye oil, containing more or less mucilage^ imported
320 GALL NUTS.
from a seaport so named, of tbe province of OtrantOi in the kingdom of Naples. See
Olive Oil.
GALL-NUTS, or GALLS (Noix de GaOe, Fr. ; GoMpfd, Germ.), are ex-
crescences found upon the leaves and leaf-stalks of a species of oak, called Querctu m-
fectoria, vhich grows in the Levant. They are produced in conseqoence of die
puncture of the female of the gall wasp {CynipsfoUi quercusy, made in order to depo«t
her eggs ; round which the juice of the tree exudes, and dries in concentric portioDS.
When the insect gets fully formed, it eats through the nut and flies off.
The Levant gtdls aredftwo different appearances and qualities ; the first are heavy,
compact, imperforated, the insect not having been sufficiently advanced to eat its way
through Ae sheU ; prickly on the'surface ; of a blackish or bluish green hue ; about
the size of a musket ball These are called blacky blue, or Aleppo galls. The second
are light, spon^, pierced with one or more holes ; smooth upon the surface, of a pale
greyish or reddish yellow colour, generally larger than the first, and are called while
galls *, but they are inferior to the former, and great care should be taken in the pnr<
chase of the best quality, for these are often dyed by dishonest traders to imitate the
best blue Aleppo galls, but the fhiud may be detected by the small hole made by the
msect in the white galls, so that if the blue galls have holes, we may be sure they are
not genuine.
Besides the galls of the Levant, others come fVom Dalmatia, Illyria, Calabria,
&c. ; but they are of inferior quality, being found upon the Qucrciu ccrria\ they are
smaller, of a brownish colour, and of inferior value. The further south the galls are
grown, they are reckoned the better.
Galls consist principally of three substances ; tannin, or tannic acid ; yellow extrac-
tive ; and gallic acid. Their decoction has a very astringent and unpleasant bitter taste*
The following are their habitudes with various reagents : '—
Litmus paper is powerfully reddened.
Stannous chloride {protomuriate ofHn) produces an Isabel yellow precipitate.
Alum ; a yellowish grey precipitate.
Acetate of lead ; a thick yellowish white precipitate.
Acetate of copper ; a chocolate brown precipitate.
Ferric sulphate (red sulphate of iron) ; a blue precipitate.
Sulphuric acid ; a dirty yellowish precipitate.
Acetic acid brightens the muddy decoction.
The galls of the Quercits cerris and common oak (^Gattes a Tipine, Fr. ; Knoppem,
Germ.) are of a dark-brown colour, prickly on the surface, and Irregular in shape and
size. They are used chiefly for tanning in Hungary, Dalmatia, and the southern pro-
vinces of the Austrian states, where they abound.
Tannin or tannic acid is prepared as follows : Into a long narrow glass adopter tube,
shut at its lower orifice with a cotton wick, a quantity of pounded galls are put, and
slightly pressed down. The tapering end of the tube being inserted into a matrass or
bottle, the vacant upper half of the tube is filled with sulphuric ether, and then closed
with a ground-glass stopper. Next day there will be found in the bottle a liquid in
two distinct strata; of which the more limpid occupies the upper part, and the other,
of a'sprupy consistence and amber colour, the lower. More ether must be filtered
through the galls, till the thicker liquor ceases to augment Both are now poured
into a funnel, closed with the finger, and after the dense liquor is settled at the lx>ttom,
it is steadily run off into a capsule. This, after being washed repeatedly with ether,
is to be transferred into a ^ve chamber, or placed under the receiver of an air pump
to be evaporated. The residuary matter swells up in a spongy crystalline form of
considerable brilliancy, sometimes colourless, but more frequently of a faintly yel-
lowish hue.
This is pure tanuin, which exists in galls to the amount of from 40 to 45 per cent It
is indispensable that the ether employed in the preceding process be previously
agitated with water, or that it contain some water, because by using anhydrous ether,
not a particle of tannin will be obtained.
Tannic acid is a white or yellowish solid, inodorous, extremely astringent, very solu-
ble in water and alcohol, much less so in sulphuric ether, and uncrystallisable Its
watery solution, out of contact of air, undergoes no change ; but if, in a very dilute state,
it be left exposed to the atmosphere, it loses gradually its transparency, and lets fail
a slightly greyish crystalline matter, consisting almost entirely of gallic acid. For pro-
ctiring this acid in a perfectly pure state, it is merelv necessary to treat that solution
thus changed with animal charcoal, and to filter it m a boiling state, through paper
previously washed with dilute muriatic acid. The gallic acid will fhll down in crystals
as the liquid cools.
If the preceding experiment be made in a graduated glass tube containing oxygen
over mercary, this gas will be absorbed, and a corresponding volume of carbonic acid
Compated
CwU.
real Taliac
- 437
-
- £2,092
- 333
.
^
- 1,594
-2,113
-
- 10,116
-3,135
-
- 15,009
- 382
-
• 1,829
- 936
-
- 4,481
- 744
-
- 3,562
GALVANISED IRON. 821
gu will be disengaged. In this case the liquor will appear in the course of a few weeks
as if trarerBed with nnmerons crystalline colourless needles of gallic acid.
Tannin or tannic acid consists of carbon, 51*56 ; hydrogen, 4*20 ; oxygen, 44*24.
From the above facts it is obyious that gallic acid does not exist ready fonned in
gall-nuts, but tluat it is produeed by the reaction of atmospheric oxygen upon the tannin
of these concretions.
Gallie add is a solid, feebly acidulous and styptic to the taste, inodorous, crystallis-
ing in silky needles of the greatest whiteness ; soluble in about 100 times its weight of
cold, and in a much smaller quantity of boiling water ; more soluble in alcohol thsn in
water, but little so in sulphurie ether.
Gallic acid does not decompose the salts of protoxide of iron, but it forms, with the
sulphate of the peroxide, a dark blue precipitate, much less insoluble than the tannate
of iron.
Galls tM^orUd in 1857 :—
From France-
M Greece
„ Turkey Proper -
„ Syria and Palestine
^ United States
„ British East Indies
„ Other parts -
8,080 £38,683
GALVANISED IRON. This is the name, improperly given, first in France, and
sabseqnently adopted in this country, to iron coated with sine by a peculiar patent
process.
In 1837 Mr. H. W. Crawfnrd patented a process for sincing iron. In the ^ Re-
peritay of PaLeni Inventions ** bis process is thus described: — Sheet iron, iron castings,
and various other objects in iron are cleaned and scoured by immersion in a bath of
water, acidulated with sulphuric acid, heated in a leaden vessel, or used cold in one
of wood, just to remove the oxide. They are then thrown into cold water, and taken
out on^ at a time to be scoured with sand and water with a piece of cork, or more
usually with a piece of the husk of the cocoa nut, the ends of the fibres of which serve
as a brush, and the plates are afterwards thrown into cold water.
Pure zinc covered with a thick layer of sal-ammoniac is then melted in a bath, and
the iron, if in sheets, is dipped several sheets at a time in a cradle or grating. The
sheets are slowly raised to allow the superfluous zinc to drain ofi^, and ara thrown
whilst hot into cold water, on removal from which they only require to be wiped
dry.
Thick pieces are heated before immersion in a reverberatory furnace, to avoid
cooling the zinc. Chains are similarlv treated, and on removal from the zmc require
to be shaken until cold to avoid the links being soldered together. Nails and small
articles are dipped in muriatic acid, and dried in a reverberatory furnace, and then
thrown altogether in the sine, covered with the sal-ammoniac left for one minute, and
taken out slowly with an iron skimmer ; they come out in a mass soldered together,
and for their separation are afterwards placed in a crucible and surrounded with
charcoal powder, then heated to redness and shaken about until cold for their separa-
tion. Wire is reeled through the zinc, into which it is compelled to dip by a fork or
other contrivance. It will be underatood that the zinc is melted with a thick coat of
sal-ammoniac to prevent the loss of zinc by oxidation.
Mr. Mallett coated iron with zinc by the following process: —
The plates are immersed in a cleansing bath of equal parts of sulphuric or muriatic
acid and water, used warm ; the works are then hammered and scrubbed with emery
and sand to detach the scales, and to thoroughly clean them ; they are then immersed
in a ** preparing bath " of equal parts of saturated solutions of muriate of zinc and sal-
ammoniac, from which the works are transferred to a fluid metallic bath, consisting of
202 parts of mercury and 1292 parts of zinc, both by weight, to every ton weight of
which alloy is added above one pound of either potassium or sodium, the latter being
preferred. As soon as the cleaned iron-works have attained the melting heat of the
triple alloy, they are removed, having become thoroughly coated with zinc. At the
proper fusing temperature of this alloy, which is about 680° Fabr., it will dissolve a
plat^ of wrought iron of an eighth of an inch thick in a few seconds.
Morewood and Bogen's galvanised tinned iron is prepared under several patents.
Their process is as follows: —
The sheets are pickled, scoured, and cleaned just the same as for ordinary tinning.
VoulL Y
822 GANGUE.
A large wooden bath is tben half filled with a dilate solation of nmriate of tin, ptre-
pared by dissoWiDg metallic tin in concentrated mnriatic acid, which requires a period
of two or three days. Two quarts of the saturated solution are added to 300 or 400
gallons of the water contained in the bath. Over the bottom of the bath is first spread
a thin layer of finely granulated sine, then a cleaned iron plate, and so on, a layer of
granulated zinc and a cleaned iron plate alternately, until the bath is full ; the zinc
and iron together with the finid constitute a weak galvanic battery, and the tin is
deposited from the solution so as to coat the iron with a dull uniform layer of metallic
tin in about two hours.
The tinned iron is then passed through a bath containing fi aid zinc, covered with
sal-ammoniac mixed with earthy matter, to lessen the volatilisation of the sal-amno-
niac, which becomes as fluid as treacle. Two iron rollers immersed below the sur-
face of the zinc, are fixed to the bath and are driven by machinery to carry the plates
through the fluid metal at any velocity previously determined. The plates are receiTed
one by one from the tinning bath, drained for a short time, and passed at once, whilst
still wet, by means of the rollers, through the bath as described. The plates take up
a very regular and smooth layer of zinc, which, owing to the presence of the tin
beneath, assumes its natural crystalline character, giving the plates an appearance
resembling that known as the moirie metnUique. — See HunCs Handbook io the Great
Exhibition.
It is stated that galvanised iron plates cut with shears so as to expose the central
iron become zinced round the edges, and at the holes where the nails were driven.
We are also informed that ungalvanised iron will, if moist when near galvanised
plate, become zinced, and that telegraph wires, where cut through, become coated by
the action of the rain-water on the galvanised portion of the surfaces.
It has been stated that the galvanised iron is not more durable than unprotected
iron ; that, indeed, where the zinc is by any accident removed the destraction is more
rapid than ordinary. We have made especial inquiries, and find that in forges where
there is any escape of sulphur vapour the galvanised iron does not stand well ; bat
that under all ordinary circumstances it has the merit of great durability in addition
to its other good qualities.
G AL V A NO-PL A STIC. The German name of Electro-metallurgy.
GAMBIR, or GAMBIER. The Malayan name of an extract obtained from the
Vncaria Gambier, It is the Terra Japonica of tanners.
Two methods of obtaining gambir are described: one consists in boiling the leaves
in water, and inspissating the decoction; the other, which yields the best gambir,
consists in infusing the leaves in warm water, by which a fecula is obtained, which is
inspissated by the heat of the sun and formed into cakes. The best gambir is made
at Rhio, in the Isle of Brittany, in the Eastern Archipelago ; and the next best is
that of Lingin. It is principally imported from Singapore, and is used principally for
tanning, under the name of Terra Japonica, The Mimosa catechu yields a different
extract from the gambir, but catechu and gambir are often confounded.
The imporU have been 1856, 8536 tons ; 1857, 11,047 tons.
GAMBIR CATECHU. See Catechu.
GAMBOGE. {Gomme Guite, Fr.; Gutti, Germ.) Gamboge appears to have been
first brought from China about 1603, and its oriental name was said to be Ghittatewtotu
It is generally supposed to be produced from the HeU/radendron cambogimdee of
Graham, and the Xanthochymus ovaiifolius of Roxburgh. In Ceylon the gamboge is
obtained by wounding the bark of the tree in various places with a sharp stone, when
the flowers begin to appear. Gamboge is imported from Siam, by way of Singapore
and Penang. It is known in three forms. In rolls or solid cylinders ; in pipes or hollow
cylinders; in cakes or amorphous masses. Gamboge in small quantities is also
obtained in Ceylon.
Gamboge consist of-^
Resin 74-2
Soluble gum ..... 218
Moisture ...... 4*8
100*8
Gamboge is employed as an artist's colour ; it is used to colour varnishes and lae*
quers, and it is administered medicinally.
We imported in 1857, 248 cwts.
G A M M A M. A dye stuff, so called, from Tunis. Examples were sent to this conn-
try in 1851, but it does not appear to have been introduced since that time.
GANGUE. A word derived fVom the German gang, a vein or channeL It sig-
nifies the mineral substance which either encloses or usually accompanies any metallic
GARNET. 323
ore in the Tcin. Quarts, lamellar carbonate of lime, snlpliate of baryta, sulphate
and fluate of lime, generally form the gaogues ; but a great many other substances
become such when they predominate in a vein. In mineral works the first thing is
to break the mixed ore into small pieces, in order to separate the yaluable from the
useless parts, by processes called stamping, picking, sorting. See Mining.
GARANCIN. See Madder.
GARANCEUX. See Maddeb.
G A RLIC. AUium iativum. This plant is well known, and is much used in flayour-
ing sauces.
It is found by analysis to contain an acrid yolatile oil, g^m, woody fibre, albumen,
water, with sulphur, starch, and saccharine matter. The oil of garlic is a sulphide of
allyle, AUS = C«H»S.
GARNET, (firenat, Fr.) Garnet is a silicate of some base, which may be lime,
magnesia, oxide of iron, &c.
There are jiix sub-species of garnet, yis. : —
L Alununa-lime gamely consisting of the silicates of alumina and lime.
IL Ahanina-magnesia garnet^ consisting of the silicates of alumina and magnesia.
IIL Alumina-iron garnet^ consisting of the silicates of alumina and iron.
IV. Alumina-manQanese garnet, consisting of the silicates of alumina and man-
ganese.
y. Iron-lime gamete consisting of the silicates of iron and lime.
YI. Lime-chrome garnet, consisting of the silicates of lime and oxide of chromium.
L Lime-garnet, or grossular, is composed of silica, 40*1 ; alumina, 22*7; lime, 37*2
— 100*0. Colour, pale greenish, clear red, and reddish orange, cinnamou colour.
Before the blowpipe, fuses to a slightly greenish glass or enamel ; soluble, when pow-
dered, in concentrated muriatic acid.
This section comprises cinnamon-stone or Essonite, grossular or Wiluite, Roman*
zoyite, topazolite, and succinite.
II. Magnesia-garnet is of a deep coal-black colour, with a resinous lustre. The
Tariety from Arendal is composed of silica, 42*45; alumina, 22*47 ; protoxide of iron,
9*29 ; protoxide of manganese, 6*27 ; magnesia, 13*43 ; lime, 6*53 *» 100*44. — {Wacht-
meisterS) Before the blowpipe, easily fusible, forming with intumescence a dark
greyish-green globule, which is non-magnetic.
III. Iron-garnet comprises the almandine or precious garnet, allochroite, and com-
mon garnet It is composed of silica, 36*3 ; alumina, 20*5; protoxide of iron, 43*2 =
100*0. Before the blowpipe, fuses rather easily with an iron reaction.
IV. Manganese-garnet, or spessartine, is of a brownish-red colour, and is composed
of silica, 35*83 ; alumina, 18 06; protoxide of iron, 14*93; protoxide of manganese,
30-96 » 99-78. (Analysis of M. garnet from Haddam, U. S., by Segbert.) Before the
blowpipe, giyes a manganese reaction.
y. Iron-lime garnet includes aplome, colophonite, melanite, and pyreneite. These
yary in colour from dark red, brownish-black, to black, and possess a shining lustre,
which is sometimes resinous, as in colophonite.
Analysis of the aplome of Altenau : — Silica, 35*64 ; lime, 29*22 ; protoxide of iron,
30*00 ; protoxide of manganese, 3*01 ; potash, 2-35» 100*22.— Wdchtmeister.
VI. Lime-chrome garnet, or ouvaroyite, is of an emerald-green colour. Sp. gr.,
3*418. Before the blowpipe it is infusible alone, but with borax afibrds a chrome-
green glass. It occurs at Bissersk, in Russia.
Analysis by Erdmann : — Silica, 36*93; alumina, 5*68; peroxide of iron, 1-96; oxide
of chrome, 21*84; magnesia, 1-54 ; carbonate of lime, 31*66 ; oxide of copper, a trace
«99 58.
The garnet yaries greatly in transparency, fracture, and colour ; but when the
colours are rich, and the stone is free from flaws, it constitutes a yaluable gem, which
may be distinguished by the following properties *. —
The colour should be blood or cherry-red; on the one hand often mixed more or
less with blue, so as to present yarions shades of crimson, purple, and reddish yiolet,
and on the other hand, with yellow, so as to form orange-red and hyacinth brown.
The stones yary in size from the smallest pieces that can be worked to the size of
a nut When aboye that size they are scarcely eyer free from flaws, or sufficiently
transparent for the purposes of the jeweller.
The garnets of commerce are procured from Bohemia, Ceylon, Pegu, and the Brazils.
By jewellers they are classed as Syrian, Bohemian, or Cingalese, rather from their
relatiye yalue and fineness, than with any reference to the country from which they
are supposed to have been brought
Those most este^ed are called Syrian garnets, not because they come from Syria,
bat after Syrian, the capital of Pegu, which city was formerly the chief mart for the
finest garnets. The colour of the Syrian garnet is yiolet-purple, which, in some rare
y2
I
324 GAS-PIPES.
instances, yies with that of the finest oriental amethyst ; hnt it may he distinguished
from the latter hy acquiring an orange tint hy candle-light The Syrian garnet may
he also 'distinguished from all the other varieties of garnet in preserving its coloar
(even when of considerable thickness and nnassisted by foil), nnmixed with the black
tint which usaally obscures this gem. The Bohemian garnet is generally of a doll
poppy-red colour, with a very perceptible hyacinth-orange tint when held between
the eye and the light When the colour is a full crimson it is called pyrope, or fire
garnet, a stone of considerable value when perfect and of large size.
The best manner of cutting the pyrope is en cahochon^ with one or two rows of small
facets round the girdle of the stone. The colour appears more or less black when
the stone is cut in steps, but when cut en eabochon^ the points on which the light falls
display a brilliant fire-red.
Garnet is easily worked, and when fiieet-cat is nearly always (on account of the
depth of its colour) formed into thin tables, which are sometimes concave or hollowed
out on the under side. Cut stones of this latter description, when skilfully set, with a
bright silver foil, have often been sold as rubies.
The garnet may be distinguished from corundum or spinel by its duller colour.
Coarse garnets reduced to a fine powder are sometimes used as a substitute for emery
in polishing metals.
Bohemian garnet See Ptrope. — H. W. B.
GAS. (Crew, Fr. ; Gaz, Germ.) The generic name of all such elastic fluids as are
aeriform under a considerable pressure, at tiie zero of Fahrenheit. Oxygen, hydrogen,
and nitrogen, are permanent gases ; many of the other vaporiform bodies have been
condensed by the joint power of cold and mechanical force. See Ure*8 Dictumary q^
Chemistry,
G AS- HOLDER A vessel for containing and preserving gas, of which various forma
are described by chemical writers.
GAS, LAUGHING. Protoxide of Nitrogen ; also Protoxide of Azote, and NUrtnie
Oxide. This gas is always prepared from the nitrate of ammonia ; it was first described
by Priestiey, in 1776, and carefiiUy studied by Davy. This gas is chiefly remarkable
for the peculiar intoxication which it produces when breathed. It is not to be used
without much caution. If it is not very pure, serious consequences may ensne ; and
even when absolutely pure, the editor hais seen the nitrous oxide produce very dis-
tressing effects. It is not used in the arts. See Ure't Dictionary of Chemistry.
GASOMETER, means properly a measurer of gas, though it is employed often to
denote a recipient of gas of any kind. See CoJLl-Gas.
GAS- PI PES. When the illumination by gas was first introdaced in the large way
by Aaron Manby, Esq., then of the Horsley Iron Works, the old musket barrels, laid
by in quiet retirement from the fatigues of the last war, were employed for the con-
veyance of gas ; and by a curious coincidence, various iron foundries desisted in .a
great measure from the manufacture of iron ordnance, and took up the peaceful employ-
ment of casting pipes for gas and water.
The breach-ends of the musket-barrels were broached and tapped, and the muzzles
were screwed externally, to connect the two without detached sockets. From the
rapid increase of gas illumination, the old gun-barrels soon became scarce, and new
tubes with detached sockets, made by the old barrel-forgers, were first resorted to.
This led to a series of valuable contrivances for the manufacture of the wrought iron
tubes, commencing with the RusselVs patent iu 1824, under which the tubes were first
bent up by hand hammers and swages, to bring the edges near together ; and they
were welded between semi-circular swages, fixed respectively in the anvil, and the
face of a small tilt-hammer worked by machinery, by a series of blows along the tube
either with or without a mandrel. The tube was completed on being passed between
rollers with half-round grooves, which forced it over a conical or egg-shaped piece at
the end of a long bar to perfect the interior sur&ce.
Various steps of improvements have been since made ; for instance, the skelps were
bent at two squeezes, first to the semi-cylindrical, and then to the tubular form pre-
paratory to welding, between a swage tool five feet long worked by machinery. The
whole process was afterwards carried on by rollers, but abandoned on account of the
unequal velocity at which the greatest and least diameters of the rollers travelled
In the present method of manufacturing the patent welded tube, the end ot tiie skelp
is bent to the circular form, its entire length is raised to the welding heat in an ap-
propriate furnace, and as it leaves the furnace almost at the point of fusion it is dragged
by the chain of a draw -bench, after the manner of wire, through a pair of tongs with
two bell-mouthed jaws, these are opened at the moment of introducing the end of the
skelp, which is welded without the agency of a mandrel. •
By this ingenious arrangement wrought-iron tubes maybe made from the diameter
of six inches internally, and about one- eighth to three-eighths of an inch thick, to as
GELATINE. 325
Email as one quarter inch diameter and one-tenth bore ; and to admirably is the join-
iDg effected in those of the best description, that they will withstand the greatest
pressures of gas, steam, or water to which they have been subjected, and they admit
of being bent both in the heated and cold state almost with impunity. Sometimes
the tabes are made one upon the other when greater thickness is required, but
these stout pipes and those larger than three inches are comparatively but little used.
GASSING, in order to remove the hairy filaments from net-lace and other woven
fhbrics, they are passed over a large number of minute jets of gas, and between
rollers.
GAULT, a local term in some parts of England for day, has been adopted into
geological nomenclature to denote the argillaceous strata which separate the upper
and lower greensands. It is a dark blue or grey clay, used for making bricks and
tiles; it affords a poor agricultural soil, which is generally converted into pasture. —
H. W. B.
GAULTHERIA OIL. Winteroreen Oil, which see.
G AULTHERINE. When the powdered bark of betula lenta is exhausted with cold
alcohol of 95^ it can afford no more oil. The fiuid which contains the gaultherine has
a slightly bitterish taste, and by evaporation it forms a dry gummy mass, which at a
high heat leaves a coally residual. Oil of yitriol dissolves the gaultherine with a red
coToor and the flavour of the oil.
GAUZE WIRE CLOTH is a textile &bric, either plain or tweeled, made of brass,
iron, or copper wire, of very various degrees of fineness and openness of textures.
Its chief uses are for sieres and safe^ lamps.
GAY-LUSSITE, is a white mineral oi vitreous fhicture, which crystallises in
oblique rbomboidal prisms ; specific gravity firom 1 *93 to 1*95 ; scratches gypsum, but
is scratched by calcspar ; affords water by calcination ; it consists of carbonic acid,
28*66 ; soda, 20*44 ; lime, 17*70 ; water, 32*30 ; clay, I'Oa It is, in &ct, by my ana-
lysis, a hydrated soda- carbonate of lime in atomic proportions. This mineral occurs
abundantly in insulated crystals, disseminated through the bed of clay which covers the
wao^ or native sesquicarbonate of soda, at Lagunilla in Columbia.
GELATINE (Eng. and Fr.; Cra&rt, Zetm, Germ.) is an animal product which is
never found in the humours, but it may be obtained by boiling with water the soft and
solid parts ; as the muscles, the skin, the cartilages, bones, ligaments, tendons, and
membranes. Isinglass consists of from 86 to 93 per cent, of gelatine. This substance
is very soluble in boiling water; the solution forming a tremulous mass of jelly when
it cools. Cold water has little action upon gelatine. Alcohol and tannin precipitate
gelatine from its solution ; the former by abstracting the water, the latter by combin-
ing with the substance itself into an insoluble compound, of the nature of leather.
No other acid, except the tannic, and no alkali, possesses the property of precipitating
gelatine. But chlorine and certain salts render its solution more or less turbid ; as the
nitrate and bi-chloride of mercury, the proto-chloride of tin, and a few others.
Sulphuric acid converts a solution of gelatine at a boiling heat into sugar. Gelatine
consists of carbon, 47*88 ; hydrogen, 7*91 ; oxygen, 27*21.
Gelatine is produced by boiling the skin of animals in water, which in its crude
but solid state is called glue, and when a tremulous semi-liquid, size. See those
anicles.
A fine gelatine for culinary uses is prepared and sold as Nelson's patent gelatine. It
is thus prepared,': — After washing the parings, &c., of skin, he scores their surfaces, and
then digests them in a dilute caustic soda lye during ten days. They are next placed
in an air-ti^ht rat, lined with cement, kept at a temperature of 70^ Fahr.; then washed
in a reTolvmg cylinder apparatus with plenty of cold water, and afterwards exposed to
the fumes of burning sulphur (sulphurous acid) in a wooden chamber. They are now
squeezed to expel the moisture, and finally converted into soluble gelatine, by water in
earthen vessels, enclosed in steam cases. The fluid gelatii|e is purified by straining it
at a temperature of lOO^' or 120<^ Fahr.
A sparkling gelatine has been prepared under a patent granted to Messrs. J. and
G. Cox, of Edinburgh. By their process the substance is rendered perfectly pure,
while it possesses a gelatinising force superior even to isinglass. It msJces a splendid
calve8*-feet jelly and a milk-white blanc-mange. The patentees also prepare a semi-
solid gelatine, resembling jigubes, which readily dissolves in warm water, as also in the
mouth, and may be employed to make an extemporaneous jelly.
The gelatine of bones may be extracted best by the combined action of steam
and a current of water trickling over their crushed fragments in a properly con-
structed apparatus. When the gelatine is to be used as an alimentary article, the
bones ought to be quite fresh, well preserved in brine, or to be dried strongly by a
stoye. Bones are best crushed by passing them between grooved iron rolls. The
T 3
326 GELATINK
cDst-iran eyliaders ia irhich tlie^ are to lie stesmrd, sbonld be tbre« timM gmter :b
length than in diameter. To obtain 1000 ratiooi of gelatinona aoup dallj, a charge
of four C7linderg is required ; each beiog 3^ feet loDg. by H iocbes wide, capable of
holding 70 lbs. or boneg. These will field each hour abonL 30 galloni of a stnmg
jellj, and will require nearly 1 gallon of water in the form of aleam, and J gallons
of water to be passed through them ia the liquid state. The S quarts of jelly pro-
duced hourly by each cylicder proceeds from the 1 quartof steam-water and 4 quarts of
percolating water.
The boiler sfaould furnish ateam of abont S!3° Fabr., at a presBure of abont 4 Ibi.
on the square inch.
In Jig. 885 A, B, c, D, represents a rertical aectlon of the eylinder i a, n, i, s, a
g^^ section of the basket or cage, as
filled with the bmised bones,
* " " L '"''''*'*'* '" ^^ cylinder; e, c, c,
, the pipe which eondocta tfae
] tteam down to the hoitom of the
cylinder; L, s, a pipe for inlro-
dncing water into the interior j
M, a stopcock for regulating
the quantity of water (accm^ing
to the force of the steam preaaure
within the apparalua), which
should he 3 J quarts per hoar;
N is a lube of (in plate fitting
(ighdy into the part B of the
pipe L; it is shut at B, and per-
foraled below with a bole ; it
is inserted in its place, after the
cage full of bones has been in-
trodnced. Fig. SB6 ia an ele-
*aiTOD of Ihe apparatus, a, b,
c, », represent Uie four eylin-
ders, raised abont 30 inches
aboie the floor, and fixed in tbeir
seats by screws ; \ h, are Ihe
lidx ; g g, fabnlnrei or TaWes in
ithermometer;//, slop-cocks for drawing
plate ; n, the general gaiter of diachargc
into the cistern b ; o,a block and tackle for hoisting the cagefnl of bones in and ont
Fig. S87 is an end view of the apparatus ; n, the main steam pipe ; a, A. c, c, brancbt^s
thuc conduct the steam to the boltora of the cylinder ; o, the tackle for raising Ihe
cage ; i, stopcock ; a, small gutter; », main conduit ; b, cistern of reception.
When a strong and pure jelly is wished for, the cylinder charged with the bones is
to be wrapped in bUuikct slatf; and whi'neTer the prcase Ceases lo drop, Ihe stopcock
GEMS. 327
whiclt •dmiu the Mid water ii to be «hnl, u alio that at the bottom of Ibo oyliudcr,
which ia to Im opened onlj et the end of eveTj hoar, and eo little ai to let the geutinoel
solntloa ma out, vilhoDl alloviog acy of the ileam (o eieape with it.
Butchete' meat conlBiiu on an average ia 100 B87
pound*, U of dry flesh, 56 of water, and SO of
bone*. Theae 20 poonds can furnish 6 pounda of
alimentarf aabetaece ia a drj state ) whenoe it
appears tiiat, by the above means, ooe fourth
more DDtriiloas toetter can be obtained than ia
Dflually goL A keen dispute has been carried on
fi» Bome time in Pari*, between the partissna and
Miiersanea of gelatine as an article of food. It it
probable that both parties bare pushed their argo-
laeuts too Ikr. Calf'i-foot jelly is still deemed a
DutritiDui article by the medical mea of this coun-
try, at least, Ihoagh it ia not to be trusted to alone,
but shoold have a due admixture or interchange of
flbrioe, albumen, caseine, &C. See Nctthixioh.
Frtmch Gtlalau is Sold in cakes, marked, like
those of common ^lue, with the nets on which
they bare been dried. This gelatine is made at
Paris, from the cuttings of skins used for making
white kid gloTes ; it is coloured red, green, and
blue, ae wetl as sold colonrleas.
Swinioime'r patent r^fbitd itiiiglaii is a pure
form of gelatine, procured troat the skins of calves
cut into Tery thin slices and treated simply with
water at or about 300°.
D'/i.rcet,iBi.iaBttcrchtiMarlaSi^MlaiicanulTitiBtqueTeH/tnitg»llti Os, slates, that
ia Paris, bone* of all kinds are first digested with hydrocUoric acid to extract the
phosphate of lime, and then boiled in water under pressure. lu this way a nntrilioo*
soup is prepared for the hospitaia and other pauper establishmeots. See leiHoi-ass.
GElt^ are precious slooes, which, by their coloar, limpidity, lustre, brilliant polish,
pnrity, and rarity, are sought afltr as objects of dress and decoration. They form the
principal part of the crown jewels of kings, not oaly ftom their beauty, but because
they are suppoeed to comprise the greatest value in the smallest bulk ) for a diamond,
un larger than a not or an acorn, may be the representative sign of tbe territorial valoe
of a whole country, the equivalent in commercial exchange of a hundred forlanes
acquired by severe toils and privations.
Among these beautiful minerals mankind have agreed in fbrming a select class, to
which tbe title of genu or jactU has been appropriated ; while the term preeiou itone is
more particulaHy given to Bubitsnces which often oocur under a more considerable
TolniDU than^^H* itonti ever do.
Diamonds, sapphires, emeralds, mbie*, topaies, hyacioths, and cbrysoberyls, are
reckoaed the most valuable jrenj.
Crystalline quartz, pellacid, opalescent, or of varions hoes, amethyst, lapis lainlii
malachite, jasper, agate, &o., are ranked in the much more numerons and inferior class
of ornmmenlal stones. These distinctions are not founded upon any strict philosophical
principle, but are regulated by a conventional agreement, not very well diffined ; for it
II impossible to subject these creatures of fashion and taste to the rigid subdivisions of
science. We have only to consider the value currently attached to tbcni,and lake care
not to contbnnd two stones of the ssjne colour, but which may be very differently
priied by the virluoto.
Since 11 nsaally happens that the true gems are in a en'l and polished state, or even
set in gi^d or silver, we are thereby unable to apply to them the criteria of mineralogicnl
and chemical science. The cnttingof tbe stone has removed or masked iis crystalline
character, and cirenmslances rarely permit the phenomena of double or single refrac-
tion to be observed; while the test by the blowpipe is iundmlBslble. Hence the only
tcientiflc resources that remain are the trial by electricity, which is often inconclusive;
the degree of hardness, a criterion requiring great experience in the person whoemploya
it -, and, lastly, the proof of specific gravity, unquestionably one of the surest means of
dislingniahing tbe really fine gems from ornamental stones of similar colour. This
proof can be applied only to a stone that is not set ; but the richer gemi are nsaally
dismounted when offered for salt
Tbis character of speaiBo gravity may be applied by any person of common intelli-
gence with the aid of a small hydroatatie balance. If, for example, a stcoe of a fine
crimson-red colour bcoff<^red forsaleasan oriental ruby ; the purcbaseT must ascertain
328
GEMS, ARTIFICIAL.
if it be not a Siberian tourmaline, or ruby spinel. Sapposing its weight in ur to be 100
grains, if he finds it reduced to 69 grains when weighed in water, he condades that its
bulk is equal to that of 81 grains of water, which is its loss of weight. Now, a real
sapphire which weighs 100 grains in air, would have weighed 76*6 in water; a spinel
ruby of 100 grains would have weighed 72'2 in water, and a Siberian tounnaljne of
100 grains would hare weighed only 69 grains in water. The quality of the stone in
question, is therefore, determined beyond all dispute, and the purchaser may be thna
protected from fraud. See the Gems respectiyely.
GEMS, ARTIFICIAL. These are glasses, the material of which they are eom-
posed being called Strass.
Strtus, the paste or glass which generally forms the principal ingredient of imi-
tation gems, is called after the name of a German jeweller, by whom it was invented,
at the commencement of the last century. It is composed of silica, potash, borax, the
Tarious oxides of lead, and sometimes of arsenic : chemically it may be regarded
as a double silicate of potash and lead.
The silica may be furnished either by rock crystal, white sand, or flint : bat, of these,
the first is to be preferred, one of the principal considerations in these preparatioos
being the extreme purity of the materials or ingredients employed. In this manu-
facture, which is of more importance, and attended with greater difficulty than most
persons imagine, perfect success (independently of the choice of materials) depends apoo
the care taken, and the precautions to be observed. No crucibles should be used but
those which have been proved, both as .regards their composition, their power of with-
standing the strongest heat, and their impenetrability to Uie action of metallic oxides.
All the substances to be melted should be first pulverised, and even ground with the
greatest care. It should be remembered that the most perfect mixture can only be
effected by numerous siftings, and that a separate sieve should be used for each in-
gredient, and never be made to serve for different substances. When mixed, the
materials should be melted in a crucible placed in the middle of a cylindrical furnace
terminated in a dome, the height of which should be 7 feet 6 inches, and its diameter
4 feet 3 inches. The fuel should consist as much as possible of thoroughly dry wood,
chopped very small. The melting should be effected by means of a heat raised b j
degrees, and then steadily maintained, especially at the maximum temperatore ; then
when once the melting has been thoroughly accomplished, which cannot be in less
than from twenty to thirty hours, the crucible must be allowed to cool Tery slowly.
The art of imitating precious stones in paste has amazingly improved since the time
of Strass, as was shown by the results of the great Paris exposition of 1855. The
imitations, especially as regards certain colours, leave little to be desired ; but there
is something still in that respect in which the imitation is far from being perfect
Now that it is proved that the alkalies and vitrifiable earths are oxides of the metals,
all that has to be done to obtain the finest effects, is to combine them skilfully, and in
their present forms with otlier artificially prepared metallic oxides, which have under-
gone the process of vitrification.
Experiments ought to be made with all oxidisable and vitrifiable substances, with
the different salts, fluates, phosphates, phosphoric acid, &c.
The following are some of the mixtures generally known, but, it must be observed
here that each artist has his own processes, mgredients, and proportions.
Mixtures for Strass.
1.
2.
3.
4.
Grain*.
Grains.
Grains.
Grains.
Rock crystal
m «k
3396*2
3007-8
2897-5
3007-8
Minium
t
5280'8
- -
4231-25
—
White lead (pure) -
-
- -
5641-0
- -
5641-0
Potash (pure)
.
1804-77
1044*0
162515
1044-0
Borax . - . .
•
232-1
305-0
181-28
301-5
Arsenic
-
10-18
10-18
5-09
—
Common Strcus.
Litharge, 77-16 ; white sand, 57*73 ; potash, 7-71.
Strass of Douhaut- Wieland.
Sifted rock crystal -
Boracic acid -
Minium (purest)
2897*5
181-18
4451*37
Deutoxide of arsenio
Potash (purest)
4*92
1608*53
GEMS, ARTIFICIAL.
829
Calcined flints -
Pure potash
EngliMh Strast.
962-5 I Calcined borax
481-25 I Fine white lead
Strasa Ba»tenaire*
361-9
120-89
1.
2.
3.
4.
5.
Gralni.
Grains.
Grains.
Grains. *
Grains.
wnite sand treated witu Hydro-
chloric acid - - -
1543-23
1543*23
385-8
385-8
385-8
Miniam, first qaality
6*16
2156-
771-61
925-8
848-65
White potash, well calcined -
37032
493-76
108-2
61-72
154*32
Calcined borax ...
308-64
185-16
- •-
92-58
123-45
Crystallised nitrate of potash
(nitre)
185-16
• •
123-44
- .
77-16
Peroxide of manganese -
61*72
- -
- -
154-32
- -
Deatoxide of arsenic
9-26
• -
23-15
-
YABIOnSLT COLOUBBD 8TBA88.
Top<u : Ab. 1.
Whitest Btrass, 842*079 ; glass of antimony, 36*421 ; purple of Cassias, 0*738.
Another.
White lead of Clichy, 771-6 ; flints calcined and polverised, 771.6.
AnotKer.
White sand, well dressed - 1543-23
Borax, calcined - - 138-88
Minium .... 2237 '64
Oxide of sllrer •
Calcined potash -
- 7716
- 493-76
Sapphire: Whitest strass, 8858-087 ; pore oxide of cobalt, 57-708.
Ditto: another. Very fine strass, 481-25 -, purest oxide of cobalt, 1*697.
Emerald^ No. 1. Strass, 3858.087 ; pure green oxide of copper, 35*643 ; -oxide of
chrome, 1*697.
Ditto: ordinary. Strass, 7716*174; acetate of copper, 61-11: oxide of iron,
12*731.
Ditto: another. Strass, 481*25 ; oxide of copper precipitated from the nitrate by
potash, 334*45.
Emeralds QBastenaire).
Well washed sand ....
Minium .-----
White potash, calcined ....
Borax, calcined .....
Yellow oxide of antimony . . ~
Pore oxide of cobalt ....
Green oxide of chrome ...
1.
2.
Grains.
154-32
231-48
46-29
30 86
7-71
1-54
Grains.
15432
231-48
77-16
30-86
3-85
AXBTHTBT (^Baatenaure).
Strass
Oxide of manganese ....
Oxide of cobalt
Purple of Cassius - - - . -
Pale.
Deep coloured.
Grains.
7716-17
20*39
0-848
Grains.
3858-08
36-55
20-39
0*848
830
GERMAN SILVER.
Aqttanuaine.
Strass, 2913-50; Glass of antimoDy, 20*370 ; Oxide of cobalt, 1-265.
Sifrian GameL
Strass -------
Glass of aotimony - - . -
Purple of Cassias - - - - -
Oxide of manganese • . - -
1.
2.
Grains.
427-931
215*815
1-697
1-697
Grain*.
484-25
2-1 50
Obteroations, For topaz, No. 1, the clearest and most transparent glass of aati-
mony should be used. Frequently this mixture only yields an opaque mass, trmns-
lucent on the edges, and transmitting in thin fragments a red colour whea held
between the eye and the light : in that case rubies may be made of it.
To make them, a portion of the topaz material is taken, and mixed with eight puts
of fine strass : these are melted in a Hessian crucible for thirty hours in a potter's
furnace, and the result is a beautiful yellow glass-like strass, which, when cat, pro-
duces an imitation of the finest oriental rubies.
These may be made of another tint by using the following proportions : —
Strass, 24 U '25 ; oxide of manganese, 61-310.
In the emerald, No. 1, by increasing the proportion of chrome or oxide of copper,
and mixing with it oxide of iron, the green shade may be yaried, and the peridot or
deep tinted emerald may be imitated.
The manufacture of artificial gems has acquired an extreme development ; immense
factories are established at Septmoncal in the Jura, furnishing employment to more
than 100 work-people, who produce fieibulous quantities.
Many ingenious persons in Paris vie with one another in bringing to perfection the
most perfect processes, and produce truly surprising results. M. Savary especially, in
his magnificent collections, and his perfect imitation of celebrated diamonds, has
arrived at a degree of excellence which, apparently, can scarcely be surpassed.
We have alluded only to those imitations of gems in glass of which a large portion
of the cheap jewellery is formed. Some very successAil attempts have been made to
manufacture true gems by an artificial process. M. Ebelmen has done much in this
direction, and M. Henri Sain te- Claire Deville and M. Henri Caron communicated to
the Academy of Sciences of Paris, in April 1858, a process which they had discovered
for the production of a number of the gems which belong to the corundum class, as the
ruby, sapphire, &c. Essentially, the process consisted in exposing the fluoride of
aluminium, mixed with a little charcoal and boracic acid, in a black lead crucible, pro-
tected from the action of the air, to a white heat for about an hour. For details of
the process see Comptes Rendu*, Annahs de Chimie,
GENEVA. A grain spirit flavoured with j uniper berries, manufactured extensirely
in Holland; hence it is frequently called Holi^ands.
GENTIAN. Gentiana lutea. The common or yellow gentian, which is said to
owe its name to Gentius king of lUyria, who introduced it as a medicine about 170
years before Christ.
The roots of the gentian are collected and dried by the peasants of Switzerland, the
Tyrol, and in the Auvergne.
The bitter of the gentian is agreeable and aromati9 ; it is much used in medicine,
and has on some occasions been employed instead of hops in beer.
GEODE. A rounded nodule of stone, containing a cavity usually lined with
crystals. Geodes frequently consist of agate, calcedony, &c.
GEOGNOSY, 71J, the earth, and7i'aMrir, knowledge, — means the science of the
substances which compose the earth*s crust. It originated with the German miner-
alogists.
GEOLOGY, 717* the earth, and Koyos, a discourse. The science which treats of
the structure of the earth, and of the causes which have produced its present physical
features.
GERHARDT'S ANHYDROUS ACETIC ACID. See Acetic acid, and refer
to Ure*s Dictionary of Chemistry,
GERMAN BLACK. SeeJFRANKFORT Black.
GERMAN SILVER. See Allot and Copper. M Gersdorf, of Vienna, states that
GILDING. 831
llie proportion of the metals in this alloy shonld vary according to the uses for which it is
destined. When intended as a snbetitute for silver, it should be composed of 25 parts
of nickel, 25 of sine, and 50 of copper. An alloy better adapted for rolling consists of
25 of nickel, 20 of zinc, and 60 of copper. Castings, such as candlesticks, bells, &c.,
may be made of an alloy, consisting of 20 of nickel, 20 of sine, and 60 of copper ; to
vhich 3 of lead are added. The addition of 2 or 2} of iron (in the shape of tin
pUie?) renders the alloys much whiter, bat, at the same time, harder and more
brittle.
Keferstein has given the following analysis of the genuine German silver, as made
from the original ore found in Hildburghausen, near 8uhl, in Henneberg:*-
Copper --------- 40*4
Nickel - - - - 31*6
Zinc --------- 25*4
Iron ---------2*6
lOOH)
Chinese pakfong, a white alloy, according to the same authority, consists of 5 parts
of copper, alloyed with 7 parts of nickel, and 7 parts of sine.
The best alloy for making bearings, bushes, and steps for the steel or iron gudgeons,
and pivots of machinery to run in, is said to consist of 90 parts of copper, 5 of
zinc, and 5 of antimony.
GERMAN STEEL. A metal msde of a white iron in forges where charcoal is em-
ployed, the ores used being either bog-iron ore or the sparry carbonate.
GERMAN TINDER. See Amax>ou.
GERMINATION. (Eog. and Fr.; Das KeimeHy Germ,) The first indication of
vital force in the embryo plant The seed being placed in the soil, a proper tem-
perature existing, and a due quantity of water being supplied, a chemical action is
established, and heat is developed. In fact, a slow combustion takes place, during
which oxygen is combined with carbon, and carbonic acid is liberated. The starch
of the gram, by the process of germination, is converted into sugar by taking into com-
bination one equivalent of the elements of water. While this operation is progressing,
the embryo enlarges, sending down its root radicle into the soil, and forcing upwards,
towards the light, the cotyledons or leaf lobes, and the plumule.
These phenomena of the commencement of vegetable life can be well studied in the
process of Malting, in which the barley, by the conversion of its starch into sugar,
becomes malt
The direct action of sunlight is injurious to the germinating seed, cooseqnently it
is a law of nature that a dark soil should be the bed in which this remarkable oper-
ation commences, and is continued until the first leaves appear above the soil. In the
process of malting (which see), care is taken that the floors upon which the germin-
ation is established are but dimly illuminated.
GEROPIG A. A factitious liquor, imported from Portugal and used in this country
for the adulteration of wines. It is sometimes spelt Jebufioa. It appears to be a
compound of nnfermented grape juice, brandy, sugar, and colouring matter. This
compound is used even more extensively in the United States than in this country. —
(MCuUocK)
GIG MACHINES, are rotatory drums, mounted with thistles or wire teeth for
teazling cloth. See Wooxxen Mi^UFAcruBB.
GILDING. {Dorure, Fr. ; Vergoldung, Germ.) This art consists in covering bodies
with a thin coat of gold, which may be done either by mechanical or chemical means.
The mechanical m<^e is the application of gold leaf or gold powder to various sur-
ikces, and their fixation by various means. Thus gold may be applied to wood,
plaster, pasteboard, leather; and to metals, such as silver, copper, iron, tin, and
bronze; so that gilding, generally speaking, includes several arts, exercised by very
different classes of tradesmen.
L Mechanical Gildino. — Oil gilding is the first method under this head, as oil
is the fluid most generally used in the operation of this mechanical art The follow-
ing process has been much extolled at Paris.
1. A coat of impression is to be given first of all, namely, a coat of white lead paint,
made with drying linseed oil, containing very little oil of turpentine.
2. Calcined ceruse is to be ground very well with unboiled linseed oil, and tempered
with essence of turpentine, in proportion as it is laid on. Three or four coats of this
hard tint are to be applied evenly on the ornaments, and the parts which are to be
most carefully gilded.
3. The Gold colour is then to be smoothly applied. This is merely the dregs of the
colours, ground and tempered with oil, which remain in the little dish in which painters
332 GILDING.
clean their brushes. This substance is extremely rich and glaey ; after being groand
up, and passed through fine linen cloth, it forms the ground for gold leaf.
4. When the gold colour is dry enough to catch hold of the leaf gold, this is spread
on the cushioD, cut into pieces and carefully applied with the pallet knife, pressed dova
with cotton, and on the small ornaments with a fine brush.
5. If the gildings be for outside exposure, as balconies, gratings, statues, &c., they
must not be Tarnished, as simple oil gilding stands better ; for when it is varnished, a
bright sun-beam acting after heavy rain, gives the gilding a jagged appearance.
When the objects are inside ones, a coat of spirit varnish may be passed over the gold
leaf, then a glow from the gilder's chafing dish may be given, and finally a coat of oil
varnish. The workman who causes the chafing dish to glide in front of the varnished
surface, must avoid stopping for an instant opposite any point, otherwise he would
cause the varnish to boil and blister. This heat brings out the whole transparency
of the varnish, and lustre of the gold.
Oil Gildiftg is employed vr'iSi varnish polish, upon equipages, mirror-frames,
and other furniture. The following method is employed by eminent gilders at
Paris: — .
1. White lead, with half its weight of yellow ochre, and a little litharge, are sepa-
rately ground very fine ; and the whole is then tempered with linseed oil, thinned with
essence of turpentine, and applied in an evenly coat, called impression.
2. When this coat is quite dry, several coats of the hard tint are given, even so
many as 10 or 12, should the surface require it for smoothing and filling up the porea.
These coats are given daily, leaving them to dry in the interval in a warm sunny ex-
posure.
8. When the work is perfectly dry, it is first softened down with pumice stone and
water, afterwards with worsted cloth and very finely powdered pumice, till the hard
tint give no reflection, and be smooth as glass.
4. With a camel's hair brush, there must be given lightly and with a gentle
heat, from 4 to 5 coats at least, and even sometimes double that number, of fine lac
Tarnish.
5. When these are dry, the grounds of the pannels and the sculptures must be first
polished with shave-grass (de la prile) ; and next with putty of tin and tripoli, tempered
with water, applied with woollen cloth ; by which the varnish is polished till it shines
Hke a mirror.
6. The work thus polished is carried into a hot place, fi-ee from dust, where it re-
ceives very lightly and smoothly, a thin coat of gold colour, much softened down. This
coat is passed over it with a clean soft brush, and the thinner it is the better.
7. Whenever the gold colour is dry enough to take the gold, which is known by
laying the back of the hand on a corner of the frame work, the gilding is begun and
finished as usuaL
8. The gold is smoothed off with a very soft brush, one of camel's hair for example,
of three fingers' breadth ; after which it is left to dry for several days.
9. It is then varnished with a spirit of wine varnish ; which is treated with the
chafing dish as above described.
10. When this varnish is dry, two or three coats of copal, or oil of varnish, are ap-
plied, at intervals of two days.
1 1. Finally, the pannels are polished with a worsted cloth, imbued with tripoli and
water, and lustre is given by friction with the palm of the hand, previously softened
with a little oUtc oil, taking care not to rub off the gold.
In this country. Burnished gilding is practised by first giving a ground of size
whiting, in several successive coats ; next applying gilding size ; and then the gold
leaf, which is burnished down with agate, or a dog's tooth.
.Gilding in disterhper of the French, is the same as our burnished gilding. Their pro-
cess seems to be very elaborate, and the best consists of 17 operations ; each of them
said to be essentiaL
1. EncoUagct or the Glue coat. To a decoction of wormwood and garlic in water,
strained through a cloth, a little common salt, and some vinegar are added. This com-
position, as being destructive of worms in wood, is mixed with as much good glue ;
and the mixture is spread in a hot state, with a brush of boar's hair. When plaster or
marble is to be gilded, the salt must be left out of the above composition, as it is apt to
attract hnnaidity in damp places, and to come out as a white powder on the gilding. But
the salt is indispensable for wood. The first glue coating is made thinner than the
second.
2. White preparation. This consists in covering the above surface, with 8, 10, or 1 2
coats of Spanish white, mixed up with strong size, each well worked on with the brush,
and in some measure incorporated with the preceding coat, to prevent their peeling off
in scales.
GILDING. 833
8). Stopping up the pores, with thick whiting and glae, and smoothing the snrfkce
with dog-skin.
4. Polishing the sorface with pumice-stone and Terj cold water.
5. ReparatUm ; in which a skilful artist retouches the whole.
6. Cleanting ; with a damp linen rag, and then a soft sponge.
7. Pr&er. This is ruhbing with horse's tail {thave-graaa) the parts to be yellowed,
in order to make them softer.
8. YeUoieing, With this yiew yeUow ochre is carefully ground in water, and mixed
with transparent colourless size. The thinner part of this mixture is applied hot over
the white surface with a fine brush, which gives it a fine yellow hue.
9. Ungraming ; consists in rubbing the whole work with shave •grass, to remove any
granular appearance^
10. Coat o/cusiette ; trencher coat This is the composition on which the gold is to
be laid. It is composed of Armenian bole, 1 pound ; bloodstone (hematite), 2 ounces ;
and as much galena ; each separately ground in water. The whole are then mixed
together, and ground up with about a spoonful of olive oil. The atsiette well made
and applied gives beauty to the gilding. The assiette is tempered with a white sheep-
skin glue, very dear and well strained. This mixture is heated and applied in three
successive coats, with a very fine long-haired brush.
11. Rubbing y with a piece of dry, clean linen cloth ; except the parts to be bur-
nished, which are to receive other two coats of assiette tempered with glue.
12. Gilding. The surface being damped with cold water (iced in summer) has
then the gold leaf applied to it The hollow grounds must always be gilded before
the prominent parts. Water is dexterously applied by a soft brush, immediately
behind the gold leaf, before laying it down, which makes it lie smoother. Any
excess of water is then removed wiUi a dry brush.
13. Burnishing, with bloodstone.
14. Dtadening, This consists in passing a thin coat of glue, slightly warmed, over
the parts that are not to be burnished.
15. Mending ; that is, moistening any broken points with a brush, and applying bits
of gold leaf to them.
16. The vermeil coat. Vermeil is a liquid which gives lustre and fire to the gold:
and makes it resemble or-moulu. It is composed as follows : 2 ounces of annotto, 1
ounce of gamboge, 1 ounce of vermilion, half an ounce of dragon's blood, 2 ounces of
salt of tartar, and 18 grains of saffron, are boiled in a litre (2 pints English) of water,
over a slow fire, till the liquid be reduced to a fourth. The whole is then passed
through a silk or muslin sieve. A little of this is made to glide lightly over the gold,
with a very soft brush.
17. Repassage ; is passing over the dead surfaces a second coat of deadening
glue, which must be hotter than the first. This finishes the work, and gives it
strength.
Leaf gildings on paper or vellum, is done by giving them a coat of gum water or
fine size, applying the gold leaf ere the surfaces be hard dry, and burnishing with
agate.
Gold lettering, on bound books, is given without size, by laying the gold leaf on the
leather, and imprinting it with hot brass types.
The edges of the leaves of books are gilded, while they are in the press where they
have been cut smooth, by applying a solution of isinglass in spirits, and lajing-on the
gold when the edges are in a proper state of dryness. The French workmen employ
a ground of Armenian bole, mixed with powdered sugar-candy, by means of white of
egg. This ground is laid very thin upon the edges, after fine size or gum water has
been applied ; and when the ground is dry it is rubbed smooth with a wet rag, which
moistens it sufficiently to take the gold.
Japanner^ gilding is done by sprinkling or daubing with wash leather, some gold
powder over an oil sized surface, nuxed with oil of turpentine. This gives the appear-
ance of frosted gold. The gold powder may be obtained, either by precipitating gold
fh>m its solution in aqua regia by a solution of pure sulphate of iron, or by evaporating
away the mercury from some gold amalgam.
IL Cheihcal Gildimg, or the application of gold by chemical affinity to metkllic
surfaces.
A compound of copper with one seventh of brass is the best metal for gilding on ;
copper by itself being too soft and dark coloured. Ordinary brass, however, answers
very well. We shall describe the process of wash gilding, with M. D'Arcet's late im-
provements, now generally adopted in Paris.
Wash gildrng, consists in applying evenly an amalgam of gold to the surface of a
copper alloy, and dissipating the mercury with heat, so as to leave the gold film fixed.
The snrfiice is afterwards burnished or deadened at pleasure. The gold ought to be
334 GILDING.
qaite pore, and laminated to facilitate its combination with themereary ; which eboold
also be pure.
Preparation of the amalgam. — After weighing the fine gold, the workman pats it in a
crucible, and as soon as this becomes faintly red, he pours in the requisite qoantitj
of mercury ; which is about 8 to I of gold. He stirs up the mixture with an iron rod,
bent hookwise at the end, leaving the crucible on the fire till he perceives that all the
gold is dissolved. He then pours the amalgam into a small earthen dish containing
water, washes it with care, and squeezes out of it with his fingers all the running mer-
cury that he can. The amalgam that now remains on the sloping sides of the vesE^i
is so pasty as to preserve the impression of the fingers. When this is squeezed in a
shamoy leather bag, it gives up much mercary ; and remains an amalgam, consisting of
about 33 of mercury, and 57 of gold, in 100 parts. The mercury which passes through
the bag, under the pressure of the fingers, holds a good deal of gold in solution ; and
is employed in making fresh amalgam.
Preparation of the mercurial solution. — The amalgam of gold is applied to brass,
through the intervention of pure nitric acid, holding in solution a little mercury.
100 parts of mercury, and 110 parts by weight of pure nitric acid, specific gravitj
1 *33, are to be pat into a glass matrass. On the application of a gentle heat the mer-
cury dissolves with the disengagement of fumes of nitrous gas, which must be allowed
to escape into the chimney. This solution is to be diluted with about 25 times its
weight of pare water, and bottled up for use.
1. Annealing. — The workman anneals the piece of bronze after it has come out of
the hands of the turner and engraver. He sets it among burning charcoal, or rather
peats, which have a more equal and lively flame ; covering it quite up, so Uiat it maj
be oxidised as little as possible, and taking care that the thin parts of the piece do not
become hotter than the thicker. This operation is done in a dark room, and when he
sees the piece of a cherry red colour, he removes the fuel from about it, lifts it out
with long tongs, and sets it to cool slowly in the air.
2. The decapage, — The object of this process is to clear the surface from the coat of
oxide which may have formed upon it. The piece is plunged into a backet filled with
extremely dilute sulphuric acid •, it is left there long enough to allow the coat of oxide
to be dissolved, or at least loosened ; and it is then rubbed with a hard brush. When
the piece becomes perfectly bright, it is washed and dried. Its surface may, however,
be still a little variegated ; and the piece is therefore dipped in nitric acid, specific
gravity 1 '33, and afterwards rubbed with a long-haired brush. The addition of a
little common salt to the dilute sulphuric acid would probably save the use of nitric
acid, which is so apt to produce a new coat of oxide. It is finally made quite dry
(after washing in pure water), by being rubbed well with tanners* dry bark, sawdust,
or bran. The surface should now appear somewhat depolished ; for when it is very
smooth, the gold does not adhere so well.
3. Application of the amalgam, — The gilder*s scratch-brush or pencil, made with
fine brass wire, is to be dipped into the solution of nitrate of mercury, and is
then to be drawn over a lump of gold amalgam, laid on the sloping side of an earthen
vessel, after which it is to be applied to the surface of the brass. This process is to be
repeated, dipping the brush into the solution, and drawing it over the amalgam, till the
whole surface to be gilded is coated with its just proportion of gold. The piece is then
washed in a body of water, dried, and put to the fire to volatilise the mercury. If
one coat of gilding be insufficient, the piece is washed over anew with amalgam, and
the operation recommenced till the work prove satisfactory.
4. Volatilisation of the mercury. — Whenever the piece is well coated with amalgam,
the gilder exposes it to glowing charcoal, turning it about, and heating it by degrees
to the proper point ; he then withraws it ft*om the fire, lifts it with long pincers, and,
seizing it in his left hand, protected by a stufied glove, he turns it over in every di-
rection, rubbing and striking it all the while with a long-haired brush, in order to
equalise the amalgam. He now restores the piece to the fire, and treats it in the same
way till the mercury be entirely volatilised, which he recognises by the hissing sound
of a drop of water let fall on it. During this time he repairs the defective spots, taking
care to volatilise the mercury very slowly. The piece, when thoroughly coated with
gold, is washed, and scrubbed well with a brush in water acidulated with vinegar.
If the piece is to have some parts burnished, and others dead, the parts to be bur-
nished are covered with a mixture of Spanish white, bruised sugar-candy, and gum
dissolved in water. This operation is called in French epargner (protecting). When the
gilder has protected the burnished points, he dries the piece, and carries the heat high
enough to expel the little mercury which might still remain on it He then plunges
it, while still a little hot, in water acidulated with sulphuric acid, washes it, dries it,
and gives it the burnish.
5. The burnish is given by rubbing the piece with burnishers of hematite (blood-
GILDING.
835
stone). The workman dips his burnisher in water sharpened with vinegar, and mbs
the piece always in the same direction backwards and forwards, till it exhibits a fine
polish, and a complete metallic lustre. He then washes it in cold water, dries it with
fine linen cloth, and concludes the operation by drying it slowly on a grating placed
aboTe a chafing dish of burning charcoal.
6. The deadening is given as follows. The piece, covered with the protection on those
parts that are to be burnished, is attached with an iron wire to the end of an iron rod,
and is heated strongly so as to give a brown hue to the epargne by its partial carbon-
isation. The gilded piece assumes thus a fine tint of gold ; and is next coated over
with a mixture of sea salt, nitre and alum, fused in the water of crystallisation of the
latter salt The piece is now restored to the fire, and heated till the saline crust which
covers it becomes homogenous, nearly transparent, and enters into true fusion. It is
then taken from the fire and suddenly plunged into cold water, which separates the
saline crust, carrying away even the coat of epargne. The piece is lastly passed
through very weak nitric acid, washed in a great body of water, and dried by ex-
posure either to the air, over a drying stove, or with clean linen cloths.
7. OfoT'tnoulu colour, — When it is desired to put a piece of gilded bronze into or-
mmdu colour, it must be less scrubbed with the scratch-brush than usual, and made to
ccme back again by heating it more strongly than if it were to be deadened, and allow-
ing it then to cool a little. The or-moulu colouring is a mixture of hematite, alum,
and sea salt This mixture is to be thinned with vinegar, and applied with a brush so
as to cover the gilded brass, with reserve of the burmshed parts. The piece is then
put on glowing coals, urged a little by the bellows, and allowed to heat till the colour
begins to blacken. The piece ought to be so hot that water sprinkled on it may cause
a biasing noise. It is then taken from the fire, plunged into cold water, washed, and
next rubbed with a brush dipped in vinegar, if the piece be smooth, but if it be
chased, weak nitric acid must be used. In either case, it must be finally washed in a
body of pare water, and dried over a gentle fire.
8. Of red gM colour, — To give this hue, the piece after beine coated with amalgam,
and heated, is in this hot state to be suspended by an iron wire, and tempered with
the composition known under the name of gilder's wax ; made with yellow wax, red
ochre, verdigris, and alum. In this state it is presented to the flame of a wood fire, is
heated strongly, and the combustion of its coating is favoured by throwing some drops
of the wax mixture into the burning fuel. It is now turned round and round over the
fire, so that the flame may act equally. When all the wax of the colouring is burned
away, and when the flame
is extinguished, the piece
is to be plunged in water,
washed, and scrubbed
with the scratch-brush
and pure vinegar. If the
colour is not beautiful,
and qnite equal in shade,
the piece is coated with
verdigris dissolved in
vinegar, dried over a
gentle fire, plunged in
water, and scrubbed with
pure vinegar, or even
with a little weak nitric
acid if the piece exhibit
too dark a hue. It is
now washed, burnished,
washed anew, wiped wiUi
linen cloth, and finally
dried over a gentle fire.
The following is the
oatline of a complete
gilding factory, as now
fitted up at Pans.
Figs. 888, 889, frontele-
vation and plan of a com-
plete gilding workshop.
P. Furnace of appel, or
draught, serving at the same time to heat the deadening pan (poclon au mat) ,
P. Aih-pit of this furnace.
H. Chimney of this furnace constructed of bricks, as far as the contraction of the
889
336 GILDING.
great chimney B of the forge, and which is terminated by a smnmil pipe rising 2 or 3
yards above this contraction.
B. Forge for annealing the pieces of bronze ; for drying the gilded pieces* &c.
c. Chimney of communication between the annealing forge b, and the space i> heknr
the forge. This chimney serves to carry the noxious fumes into the great Tent of the
fiactory.
u. Bucket for the brightening operation.
A. Forge for passing the amalgam over the piece.
B. She& for the brushing operations.
E E. Coal cellarets.
0. Forge for the deadening process.
G. Furnace for the same.
iL An opening into the furnace of appd, by which yapours may be let oif finom
operation by taking out the pHig at m.
1. Cask in which the pieces of gilded brass are plunged for the deadening
The vapours rising thence are carried up the general chimney.
J J. Casement with glass panes, which serves to contract the opening of the hearths,
without obstructing the view. The casement may be render^ movable to admit
larger objects.
H H. Curt^ns of coarse cotton cloth, for closing at pleasure, in whole or part, oneor
several of the forges or hearths, and for quickening Uie current of* air in the pIaoe<
where the curtains are not drawn.
Q. Opening above the draught furnace, which serves for the heating of the poAm am
mat (deadening pan).
Gilding on polished iron and ated. — If a nearly neutral solution of gold in muriatic
acid be mixed with sulphuric ether, and agitated, the ether will take up the gold, and
float above the denser acid. When this auriferous ether is applied by a hair pencil to
brightly polished iron or steel, the ether flies off, and the gold adheres. It must be
fixed by polishing with the burnisher. This gilding is not very rich or durable. In
fact the affinity between gold and iron is feeble, compared to that between gold and
copper or silver. But polished iron, steel, and copper, may be gilded with heat, by
gold leaf. They are first heated till the iron takes a bluish tint, and till the copper has
attained to a like temperature ; a first coat of gold leaf is now applied, which is pressed
gently down with a burnisher, and then exposed to a gentle heat. Several leaves either
single or double are thus applied in succession, imd the last is burnished down
cold.
Mr. Elkington obtained a patent, in June, 1836, for gilding copper, brass, &&, by
means of potash or soda combined with carbonic acid, and with a solution of gold.
Dissolve, says he, 5 oz. troy of fine gold in 52 oz. avoirdupoise of nitro-muriatic acid of
the following proportions: viz. 21 oz. of pure nitric acid, of spec. grav. 1*45, 17 oz.
of pure muriatic acid, of spec grav. 1*15, with 14 oz. of distilled water.
The gold being put into the mixture of acids and water, thev are to be heated in
a glass or other convenient vessel till the gold is dissolved ; and it is usual to continue
the application of heat after this is effected, until a reddish or yellowish vapour ceases
to rise.
The clear liquid is to be carefully poured off from any sediment which generally
appears, and results fVom a small portion of silver, which is generally foand in alloy
with gold. The clear liquid is to be placed in- a suitable vessel of stone ; pottery ware
is preferred. Add to the solution of gold 4 gallons of distilled water, and 20 pounds of
bicarbonate of potash of the best quality ; let the whole boil moderately for 2 hours,
the mixture will then be ready for use.
The articles to be gilded having been first perfectly cleaned from scale or grease,
they are to be suspended on wires, conveniently for a workman to dip them m the
liquid, which is kept boiling. The time required for gilding any particular article
will depend on circumstances, partly on the quantity of gold remaining in the liquid,
and partly on the size and weight of the article ; but a little practice will readily give
sufficient guidance to the workman.
Supposing the articles desired to be gilded be brass or copper buttons, or small
articles for gilt toys, or ornaments of dress, such as earrings or bracelets, a consider-
able number of which may be strung on a hoop, or bended piece of copper or brass
wire, and dipped into the vessel containing the boiling liquid above described, and
moved therein, the requisite gilding will be generally obtained in from a few seconds
to a minute ; this is when the liquid is in the condition above described, and depend-
ing on the quality of the gilding desired ; but if the liquid has been used some time,
the quantity of gold will be lessened, which will vary the time of operating to produce
a given effect, or the colour required, all of which will quickly be observed by the
workman ; and by noting the appearance of the articles from time to time, he will
GIN. 837
know when the desired object is obtained, though it is desirable to avoid as much as
possible taking the articles oat of the liquid.
When the operation is completed, the workman perfectly washes the articles so
gilded with clean water ; they may then be submitted to the usual process of
colouring.
If the articles be cast figures of animals, or otherwise of considerable weight, com-
pared with the articles above mentioned, the time required to perform the process will
be greater.
In case it is desired to produce what is called a dead appearance, it may be per-
formed by several processes : the one usually employed is to dead the articles in the
process of cleaning, as practised by brass founders and other trades ; it is produced by
an acid, prepared for that purpose, sold by the makers under the term ** deading
aquafortis,'* which is well understood.
It may also be produced by a weak solution of nitrate of mercury, applied to the
articles previous to the gilding process, as is practised in the process of gilding with
mercury, previous to spreading the amalgam, but generally a much weaker soluiion ;
or the articles having been gilded may be dipped in a solution of nitrate of nuTcuiy,
and submitted to heat to eipel the same, as is practised in the usual process of
gilding.
Cold gUding, — Sixty g^ins of fine gold and 12 of rose copper are to be dissolved in
two ounces of aqua regia. When the solution is completed, it is to be dropped on
clean linen rags, of such bulk as to absorb all the liquid. They are then dried, and
burned into ashes. These ashes contain the gold in powder.
When a piece is to be gilded, after subjecting it to the preliminary operations of
softening or annealing and brightening, it is rubbed with a moistened cork, dipped in
the above powder, till the surface seems to be sufficiently gilded. Large works are
thereafter bumbhed with pieces of hematite, and small ones with steel burnishers,
along with soap water.
In gilding small articles, as buttons, with amalgam, a portion of this is taken equi-
valent to the work to be done, and some nitrate of mercury solution is added to it in
a wooden trough ; the whole articles are now put in, and well worked about with a
hard brush, till their surfaces are equably coated. They are then washed, dried, and
put altogether into an iron frying-pan, and heated till the mercury begins to fly off,
when they are turned out into a cap, in which they are tossed and well stirred about
with a painter's brush. The operation must be repeated several times for a strong
gilding. The surfaces are finally brightened by brushing them along with small
beer or ale grounds.
For the processes of gilding by electro-chemical means, see Electbottps.
GIMP, or GYMP, a silk, woollen, or cotton twist, with often a metallic wire,
but sometimes a coarse thread running through it; it is much used in coat-lace
making.
GIN, or Genevfi, from Genievre (juniper), is an ardent spirit manufactured in London,
and other places, in great quantities, and flavoured generally with juniper berries. It
is also made in Holland, and hence called Hollands gin in this country, to distinguish
it from British gin. The materials employed in the distilleries of Schiedam, are two
parts of unmalted rye ftt>m Riga, weighing about 54 lbs. per bushel, and one part of
malted bigg, weighing about 37 lbs. per bushel. The mash tun, which serves also as
the fermenting tun, has a capacity of nearly 700 gallons, being about 5 feet in di-
ameter at the mouth, rather narrower at the bottom, and 4} feet deep ; the stirring
apparatus is an oblong rectangular iron grid made fast to the end of a wooden pole.
About a barrel, a 36 gallons of water, at a temperature of from 162° to 168° (the
former heat being best for the most highly dried rye), are put into the mash tun for
every 1^ cwt of meal, after which the malt is introduced and stirred, and lastly the rye
is added. Powerful agitation is given to the magma till it becomes quite uniform ; a
process which a vigorous workman piques himself upon executing in the course of a
few minutes. The mouth of the tun is immediately covered over with canvas, and
further secured by a close wooden lid, to confine the heat ; it is left in this state for
two hours. The contents being then stirred up once more, the transparent spent wash
of a preceding mashing u first added, and next as much cold water as will reduce
the temperature of the whole to about 85° F. The best Flanders yeast, which
had been brought, for the sake of carriage, to a doughy consistence by pressure, is
now introduced to the amount of one pound for every 100 gallons of the mashed
materials.
The g^vity of the fresh wort is usually from 33 to 38 lbs. per Dicas' hydrometer;
and the fermentation is carried on from 48 to 60 hours, at the end of which time the
attenuation is from 7 to 4 lbs , that is, the specific gravity of the supernatant wash is
from 1007 to 1*004.
Vol. n. Z
338 GINGER BEER.
The distillers are induced, by the scarcity of beer-barm in Holland, to skim off &
qaantity of the yeast from the fermenting tons, and to sell it to the bakers, whereby
they ol^truct materially the production of spirit, though they probably improve its
quality, by preventing its impregnation with yeasty particles; an anpleasaat
result which seldom &ils to take place in the whisky distilleries of the United
Kingdom.
On the third day after the fermenting tun is set, the wash containing the grBins is
transferred to the still, and converted into low wines. To every 100 gallons of this
liquor, two pounds of juniper berries, from 3 to 5 years old, being added, along with
about one quarter of a pound of salt, the whole are put into the low wine still, and the
fine Hollands spirit is drawn off by a gentle and well-regulated heat, till the znapna
becomes exhausted ; the first and the last products being mixed together ; whereby a
spirit, 2 to 3 per cent above our hydrometer proof, is obtained, possessing the peea-
liar fine aroma of gin. The quantity of spirit varies from 18 to 21 gallons per
quarter of grain ; this large product being partly due to the employment of the spent
wash of the preceding fermentation ; an addition which contributes at the same time
to improve the flavour.
London gin is, as we hare stated, a com spirit, which is, however, rendered sweet
and cordial-like, by the use of several injurious substances. Plymouth gin, as mana-
factured by Coates and Co. of Plymouth, is a fiir purer spirit The rectifiers employ
a pare grain spirit and flavour with the wash of the whidcy distilleries. Mr. Brande
has given the following table of the quantities of alcohol ( sp. gr. at 60 F., 0*825) con-
tained in different ardent spirits.
PropcrHiM of Alcohol in ardent SpiriU.
In 100 partf.
Brandy -.---. 65*89 by measure.
Rum 63-68 „
Gin 51-60 „
Whisky, Scotch 54*32 „
Do. Irish 53-20 „
When wash is distilled, the fluid that comes over is called nngUngs, or lom unmet.
It is concentrated or doubled by a second distillation, and becomes raw com epirit; this
is sold to the rectifier at 11 or 25 per cent over proof.
GINGER BEER. Boil 65 gallons of river water, 1} cwt of the best loaf
sugar, and 5 lbs. of the best race ginger, bruised, half an hour ; then add the whites
of 10 eggs, beaten to a froth with 2 ounces of dissolved isinglass. Stir it well in, and
boil 20 minutes longer, skimming it the whole time. Then add the thin rinds of 50
lemons, boiling tiiem 10 minutes more. Cut 28 lbs. of good Malaga raisins in hal^
take away the stones and stalks, and put them, with the juice of the lemon, strained,
into the hogshead. Strain the hot liquor into a cooler, and when it has stood two
hours and is settied, draw it off the lees, clear, and put it into the cask ; filter the
thick and fill up with it. Leave the bung out, and when at the proper temperatare^
stir 3 quarts of thick fresh ale yeast well into it ; put on the bune lightly, and let it
ferment 6 or 7 days, filling up with liquor as it ferments over. When the fermenta-
tion has ceased, pour in 6 quarts of French brandy, and 8 ounces of the best isinglass,
dissolved in a gallon of the wine ; then secure the bung effectually, and paste paper
over it, &c. Keep it 2 years in a cool cellar, then bottie it, using the best corks, and
sealing them ; and when it is 4 years old commence using it
There can be no doubt but that the above receipt by Dr. Ure forms an excellent
ginger beer, but it is a totally different thing from the ginger beer of the shops. The
following is a good and useful form for its manufacture : —
Barbadoes ^nger root ... - - 12 ounces.
Tartaric acid .--....3 ounces.
White sugar .......8 pounds.
Own. arable •--....8 ounces.
■ Eibelice f>f lemon ...... 2 drachms.
Watter -* 9 gaUons.
The ginger. rQ0t»,iurQised, is to be boiled for an hour, then the liquor being strained,
the tartaric acid and sugar added, boiled and the same removed. The gum arabic
dissolved in a sepalrate portion of water, added with the essence of lemons. When
the whole has cooled to about 100^ Fabr., some fresh yeast is to be added, and the
beer carefully fermented, Theu bottle for use.
Ginger beer powders are ihus prepared : —
»»
GLASS. 339
White TOgar Soances.
Tartaric acid - - - - - - ' H ounce.
Carbonate of soda ...... i| oance.
Powdered Jamaica ginger - «... s drachnu.
Essence of Lemon - - • - . - lo drops.
All the materials are to be careAilly dried, and mixed while yet warm, in a warm
mortar, and immediately bottled.
If the acid and the carbonate of soda are kept separate, these precantions are not
neoeasaiy.
GINNING is the name of the operation by which the filaments of cotton are sepa-
rated from the seeds. See Cotton Manufacture.
GIRASOL. The name given by the French to fire opal. See Opal.
GL AIRE. The white of egg. This consists according to Gmelin of albumen, 1 2*0,
mucus, 2*7, salts, 0*3, water, 85H). Glaire or albumen (ooalbumen) is distinguished from
the albumen of the serum of the blood (seraUmmenX by its being coagulated by ether.
Glaire is used by bookbinders in finishing the backs of books, and for a few other
purposes in the arts. See Albumen.
GLANCE COAL, a name given to anthracite, of which there are two varieties,
the slaty and the conchoidaL See Anthracite and Coal.
GLASS {Verre, Fr. ; G&», Germ.) is a transparent solid formed by the fusion of
siUceous^md alkaline matter. It was known to the Phosnioians, and constituted for
a long time an exclusive manu^ture of that people, in consequence of its ingredi-
ents, natron, sand, and fuel, abounding upon their coasts. It is certun that the
ancient Egyptians were acquainted with glass, for, although we find no mention of it
in the writings of Moses, we discover glass ornaments in tombs which are as old as
the days of Moees. According to Pliny and Strabo, the glass works of Sidon and
Alexandria were famous in their times, and produced beautiful articles, which were
cut, engraved, gilt, and stained of the most brilliant colours, in imitation of precious
stones. The Romans employed glass for various purposes ; and have left specimens
in Hercnlaneum of window-^lass, which must have been blown by methods analogous
to the modem. The Phoenician processes seem to have been learned by the Crusaders,
and transferred to Venice in the 13th century, where they were long held secret, and
formed a lucrative commercial monopoly. Soon after the middle of the seventeenth
century Colbert enriched France with the blown mirror glass manufacture.
Chance may have had. a share in the invention of this curious fabrication, but there
▼ere circumstances in the most ancient arts likely to lead to it ; such as the Aising
and vitrifying heats required for the formation of pottery, and for the extraction of
metals from their ores. Pliny ascribes the origin of glus to the following accident
A merchant ship laden with natron being driven upon the coast at the mouth of the
river Belus, in tempestuous weather, the crew were compelled to cook their victuals
ashore, and having placed lumps of the natron upon the sand, as supports to the
kettles, found to their surprise masses of transparent stone among the cinders. The
sand of this small stream of Galilee, which runs from the foot of Mount Carmel, was
in consequence supposed to possess a peculiar virtue for making glass, and continued
for ages to be sought after and exportied to distant countries for this purpose. There
exists good evidence that the manufacture of glass, and of vitreous glues is much
older than the time ascribed by Pliny.
Agricola, the oldest author who has written technically upon glass, describes fur-
naces and processes closely resembling those employed at the present day. Neri,
Kunckel, Henckel, Pott, Achard, and some other chemists, have since then composed
treatises upon the subject ; but Neri, Bosc, Antic, Loysel, and Allut, in the Ency*
dcpidie Methodiqtie, are the best of the older authorities.
The Venetians were the first in modem times who attained to any deg^e of ex-
cellence in the art of working glass, but the French became eventually so zealous of
rivalling them, particularly in the construction of mirrors, that a decree was issued by
the court of France, deels^ing not only that the manufacture of glass should not dero-
gate from the dignity of a nobleman, but that nobles alone should be masters of glass-
works. Within the last 30 or 40 years. Great Britain has made rapid advances in this
important art, and at the present day her pre-eminence in some departments hardly
admits of dispute.
The window-glass manufacture was first begun in England in 1.557, in Crutched
Friars, London ; and fine articles of flint-glass were soon afterwards made in the
Savoy House, Strand. In 1635 the art received a g^at improvement from Sir
Robert Mansell, by the use of coal fiiel instead of wood. The first sheets of
blown glass fbr looking-glasses and coach windows were made in 1673 at Lamheti^
by Venetian artisans employed under the patronage of the Dukeuif Baakingbaiii«
£ 2
340
GLASS.
The easting of mirror-plates was commenced in France about tlie year 1688,
by Abraham Thevart ; an invention which gave rise soon afterwards to the e8ta1>-
lishment of the celebrated works of St Gobain, which continued for nearly a
centary the sole place where this highly-prized object of luxury was well made. In
cheapness, if not in excellence, the French mirror-phite has been for some time riTalled
by the Euglish.
The analysis of modem chemists, which will be detailed in the course of this
article, and the light thrown upon the manufacture of glass in general by the acca-
rate means now possessed of puriQring its several ingredients, would have brooght
the art long since to the highest state of perfection in this country, but for the lon^
continued Texations interference and obstructions of our excise laws now happily at
an end.
The researches of Berzelins having removed all doubts concerning the acid character
of silica, the general composition of glass presents now no difficulty of cooceptiom.
This substance consists of one or more salts, which are silicates with bases of potash,
soda, lime, oxide of iron, alumina, or oxide of lead ; .in any of which compounds we
can substitute one of these bases for another, provided that one alkaline base be left.
Silica in its turn may be replaced by the boracid acid, without causing the glass to
lose its principal characters.
Under the title glass are therefore comprehended various substances fusible at m
high temperature, solid at ordinary temperatures, brilliant, generally more or leas
transparent, and always brittle. The following chemical distribution of ^^Kses has
been proposed : ^—
1. Soluble glass ; a simple silicate of potash or soda ; or of both these alkalies^
2. Crown glass ; silicate of potash and lime.
3. Bottle glass ; silicate of soda, lime, alumina, and iron.
4. Common window glass ; silicate of soda and lime ; sometimes also of potash.
5. Plate glass ; silica, soda or potash, lime, and alumina.
6. Ordinary crystal glass ; silicate of potash and lead.
7. Flint glass ; silicate of potash and lead ; richer in lead than the preceding.
8. Strass ; silicate of potash and lead ; still richer in lead.
9. Enamel ; silicate and stannate or antimoniate of potash or soda, and lead.
The following analyses of these varieties of glass will place the composition
completely before the reader : —
1. Soluble glass
Silicic
Acid.
PotMb or
floda.
Lime.
Oxide of
Lead.
Alumina.
Water.
62
26
0
0
0
13
2. Crown glass
63
22
12
0
3
0
3. Bottle glass
54
6
20
Sox.iron
0
0
4. Window glass
69
Msoda
13
0
7
0
5. Plate glass
72
\7soda
6
2 ox, iron
2
0
6. Crystal - - .
61
6
0
33
0
0
7. Flint glass
45
12
0
43
0
0
8. Strap ...
38
8
0
53
1
0
9. Enamel ...
81
8
0
50
10 or. ^R
0
Bohemian glass has not been named among the varieties. It has been generally
grouped with the English glass as containing no lead, but it has some special peca>
liarities, as the following analyses by Peligot will show ; —
Bohemian glass
Do. opal glass
Do. mirror glass -
Do. hard glass (as
analysed by Mr. Kowney)
Silica.
Potash.
Line.
Alomioa.
Soda.
760
80-9
67-7
730
150
17-6
21-0
11-5
8-0
•7
9-9
10-5
1-0
•8
1-4
3-0
0
0
0
3
In the following table is also given the analyses of a certain number of Bohemian
glasses, which will indicate their composition with precision^ and show how uncertain
their composition is.
GLASS.
341
0)
(2.)
(3.)
(4.)
(5.)
(6.)
(7.)
(8.)
SUica -
Potassa - . .
Soda ...
Lime - - -
Magnesia
Alomina - - •
Oxide of Iron -
Oxide of Bianganese -
71*6
11*0
10*
2*3
2-2
3-9
0*2
71*7
12*7
2-3
10*3
0*4
0*3
02
69*4
11*8
* *
9*2
9*6
62*8
221
12-5
2*6
75-9
17-5
3-8
2*8
78*85
5-5
12-05
6-6
3*5
70*
20-
4*
5-
0*6
0-4
67-
25-
12*5
3-
1*3
0*4
101*2
981
100-
100*
100'
100-5
100-
99*2
(1.) Bohemian glass fVom Neofeld (M. Grns),
(2.) A fine table glass from Nenwelt (M. Berthter); it is exceedingly beautiful, and
18 prepared, according to Bl. Perdonnet, irith a mixture of 100 quartz, 50 caustic lime,
75 carbonate of potassa, and a very small quantity of nitre, arsenious acid, and oxide
of manganese.
(3.) Old Bohemian glass (M. Dumas).
(4.) Crown glass of German manufacture (M. Dumas).
(5.) Glass for mirrors (M. Dumas).
(6.) Another glass for mirrors (Bl. Dumas).
(7.) White table glass, from Silberberg near Gratzen.
(8.) Minor glass fl'om New-Hnrkent^, for the manufacture of cast mirrors.
Peligot gives the analysis of Venetian aventurine as follows : —
Silica 67*7
Potash 6*5
Lime ----- 89
Soda 7-1
Oxide of Tin -
Oxide of Lead
Bf etallic Copper
Oxide of Iron -
2-3
11
8-9
3*5
See Aventurine.
The following analyses of different varieties of continental glass are instructive : —
Silica
No. I.
No. 2.
No. 8.
No. 4.
No. 8.
No. 6.
71*7
69-2
62-8
60-4
63*55
42-5
Potash - . -
12*7
15*8
22-1
3*2
5-48
11-7
Soda . . -
2*5
3*0
m m
S. pot
Lime ...
10-3
7*6
1 5
207
29-22
0-5
Alumina - - -
0*4
1-2
1
10*4
6*01
1-8
Bf agnesia . - -
- -
2-0
y 2*6
0*6
Oxide of iron -
0-3
0-5
J
3*8
5-74
— manganese
0*2
— lead
. —
.
.
-
.
43*5
Baryta ...
-
-
0*9
No. 1. is a very beautiful white wineglass of Neuwelt in Bohemia.
No. 2. Glass tubes, much more fusible than common wine glasses.
Na 3. Crown glass of Bohemia.
Na 4. Flask glass of St Etienne, for which some heavy spar is used.
Na 5. Glass of Sevres.
No. 6. Guinand*s flint glUss.
Ancient glass has the following composition ; the analyses are by Richard Phillips :•
Roman bufe ...
Do. Flatted glass -
Da Lacbrjmatory -
BUUsa.
AlnmlBt.
OsIdaoC
iMO.
HanguMM.
Hal*.
HainiMte.
Soda.
70*58
71-95
71*45
1-60
trace:
3-15
0*53
8-45
108
C48
0-57
*17
B'OO
7-88
814
trace
0-60
trace
lSfl6
15-30
16-6S
Thus we see that the ancient glasses were all soda glasses.
The glasses which contain several bases «re liable to suffer different changes when
z 3
342 GLASS.
they are melted or cooled sUwly. The silica is dmded among these baaea, fionnin^
new compounds in definite proportions, which by crystallising separate from, each
other, so that the general mixture of the ingredients which constitute the glass is
destroyed. It becomes then very hard, fibrtvis, opaque, much less fusible, a better
conductor of electricity and of heat; forming what Reaumur styled devitrified glass ;
and what is called after him Reaumur's porcelain.
This altered glass can always be produced in a more or less perfect state, bj
melting the glass and allowing it to cool very slowly ; or merely by heating it to the
softening pitch, and keeping it at that heat for some time. The process succeeds
best with the most complex vitreous compounds, such as bottle glass ; next with
ordinary window glass ; and lastly with glass of potash and lead.
This property ought to be kept constantly in view in manuikctnring glass. Tt
shows why in making bottles we diouM fkshion them as quickly as possible with the
aid of a mould, and reheat them as seldom as may be absolutely necessary. If glass
is often heated and cooled, it loses its ductility, becomes refractory, and exhibits a
multitude of stony granulations throughout its substance. When coarse g'lass is
worked at the enameUer^s lamp, it is apt to change its nature in the same way, if the
workman be not quick and expert at his business.
Fusibility, Cooling, Annealing, Devitrification, — All glass is more or less fbstble ;
when it is softened by the action of heat, it may be worked with the greatest ease, and
may be drawn out into threads as fine as those of the cocoon of the silkworm. GbsSi
when it is submitted to rapid cooling, becomes very fragile, and presents sereral Tery
remarkable phenomena, among which as an example Prince Rnpert^s drops may be in-
stanced. Glass supports variations of temperatures better in proportion as it has been
more slowly cooled ; thus, when it has been slightly annealed, or not at all, its fraffility
may be considerably diminished by annealing it in water, or better, in boiling oiL
Action of Atmospheric and Chemical Agents, — The harder and more iniosible a
glass is, the less it is alterable by the action of atmospheric and chemical agents, with
the exception of hydrofluoric acid. Glass which is too idkaline attracts gradoally the
moisture of the air, and loses its lustre and polish. Many glasses are perceptibly
attacked by a prolonged boiling with water, and a fortiori by acid and idkaline seda-
tions ; thus, the bottle glass is frequently attacked by the tartar which is found in the*
wine. According to Gu jton- Morveau, all glass which is attacked by prolonged
boiling with concentrated solutions of alum, common salt, sulphuric acid, or potassa,
is of bad quality.
From these facts we perceiTc the importance of making a earefbl choice of the glass
intended to be worked m considerable masses, such as the large object glasses of tele-
scopes ; as their annealing requires a Tery slow process of refrigeration, which is apt
to cause devitrified specks and clouds. For such purposes, therefore, no other species
of glass is well adapted except that with bases of potash and lead { or that with bases
of potash and lime. These two form the best flint glass and crown glass ; and they
should be exclusively employed for the construction of the object glass^ of achromatic
telescopes.
Glass, it will be apparent firom the analyses given, may be defined in technical
j)hraseology, to be a transparent homogeneous compound formed by the fusion of
silica with oxides of the alkaline, earthy, or common metals. It is usually colourless,
and then resembles rock crystal, but is occasionally stained by accident or design with
coloured metallic oxides. At common temperatures it is hard and brittle, in thick
pieces ; in thin plates or threads, flexible and elastic *,' sonorous when struck; firactnre
conchoidal, and of that peculiar lustre called vitreous ; at a red heat, becoming soft,
ductile and plastic. Other bodies are capable of entering into vitreous fusion, as
phosphoric acid, boracic acid, arsenic acid, as also certain metallic oxides, as of
lead and antimony, and several chlorides; some of which are denominated
glasses.
Silica, formerly styled the earth of flints, which constitutes the bans of all com-
mercial glass, is infusible by itself in the strongest fi^ of oar furnaces ; but its
vitreous fusion is easily effected by a competent addition of potash or soda, either
alone or mixed with lime or litharge. The silica, which may be regarded as be-
longing to the class of acids, combines at the heat of fusion with these bases, into
saline compounds ; and hence glass may be viewed as a silicate of certain oxides,
in which the acid and the bases eitist in equivalent proportions. Were these pro.
portions, or the quantities of the bases which silica requires for its saturation at
the melting point, exactly ascertained, we might readily determine beforehand the
best proportions of materials for the glass manufacture. But as this is far from
being the case, and as it is, moreover, not improbable that the capacity of satura-
tion of the silica varies with the temperature, and that the properties of glass also
vary with the bases, we must in the present state of our knowledge, regulate the
GLASS. 343
proportions rather bj prACtice than by theory, thoagh the latter may throw an in-
direct light apon the sal^ject. For euunple, a good colonrless glass has been found
by analysis to consist of 72 parts of silica, 13 parts of potash, and 10 parts of
lime^ in 95 parts. If we redace these numbers to the equivalent ratios, we shall
have the following results, taking the atomic weights as given by Berzelius: —
1 atom potash -B 590 14*67
I lime 856 8*84
8 silica 1722 42-79 \,, .»
9 silica 1155 2870 j'**^
3828 95-00
This glass would therefore have been properly better compounded with the just
atomic proportions, to which it nearly approaches, viz. 71-49 silica, 14*67 potash, and
8*84 lime, instead of those given above as its actual constituents.
The proportions in which silica unites with the alkaline and other oxides are mo-
dified by the temperature as above stated ; the lower the heat, the less silica will enter
into the glass, and the more of the base will in general be required. If a glass which
contains an excess of alkali be exposed to a much higher temperature than that of its
formation, a portion of the base will be set free to act upon the materials of the earthen
pot, or to be dissipated in fumes, until such a silicate remains as to constitute a per-
manent glass corresponding to that temperature. Hence the same mixture of vitrifiabl<!
materials will yield very different results, according to the heats in which it is fused
and worked in the glasshouse ; and therefore the composition should always be re-
ferrible to " the going " of the furnace. When a species of glass, which at a high
temperature formed a transparent combination with a considerable quantity of lime, is
kept for some time in fhsion at a lower tem^rature, a portion of the lime unites with
the silica into another combination of a semi-vitreous or even of a stony aspect, so as
to spoil the transparency of the glass altogether. There is probably a supersilicate,
and a sub-silicate formed in such cases; toe latter being much the more fusible of the
two compounds. The Reaumur's porcelain already mentioned, is an example of this
species of Titreous change in which new affinities are exercised at a lower tempera-
ture. An excess of silica, caused by the volatilisation of alkaline matter with too
strong firing, will bring on similar appearances.
The specific gravity of glass varies from 2*3 to 3*6. That of least specific gravity
consists of merdy silica and potash fused together; that with lime is somewhat denser,
and with oxide of lead denser stilL Plate ^ass made from silica, soda, and lime, has
a specific gravity which Taries from 2-5 to 2*6; crystal or flint glass containing lead
from 30 to 3*6.
The density of several glasses without lead is as follows : —
Old Bohemian glass (Dumas) ----- 2*396
Bohemian bottle glass ---... 3*782
do. window glass .----- 2*642
Fine glass, called Bohemian crystal .... 2*892
Mirror glass of Cherbourg (Dumas) ... 2*506
do. St Oobain 2*488
do. Kewhaus, 1812 (Schols) .... 2*551
do. do. 1830 2*653
The power of glass to resist the action of water, alkalies, acids, air, and light, is in
general the greater the higher the temperature employed in its mani]^cture, the smaller
the proportion of its fluxes, and the more exact the equivalent ratios of its constituents.
When glass contains too mnch alkali, it is partially soluble in water. Most crystal
glass is affected by having water boiled in it for a considerable time; but crown glass
being poorer in alkali, and containing no lead, resists that action much longer, and is
therefore better adapted to chemical operations. In general also potash glass is more
apt to become damp than soda glass^ agreeably to &e respective hygrometrie pro-
perties of these two alkalies, and also to Uie smaller proportion of soda than of potash
requisite to form glass.
Air and light operate upon glass probably by their oxidising property. Bluish or
greenish coloured glasses become by exposure colourless, in consequence undoubtedly
of the peroxidisement of the iron, to whose protoxide they owed their tint ; other glasses
become purple red from the peroxidisement of the manganese. The glasses which con-
tain lead, suffer another kind of change in the air, if sulphuretted hydrogen be pre-
sent; the oxide of lead is converted into a sulphuret, with the effect of rendering the
surface of the glass opaque and iridescent The more lead is in the glass, the quicker
does this iridescence supervene. By boiling concentrated sulphuric acid in a glass
Z 4
344 GLASS.
Tessel, or upoii glass, we can ascertain its power of resisting ordinary menstma.
Good glass will remain smooth and transparent ; bad glass will become rough and
dim. The conditions of decomposition as it occurs in glass of great age, hare not
been satisfactorily explained ; the glass of the Roman tombs decomposes rrom the
surface, exfoliating in a remarkable manner, film after film, of a pearly and beauti-
fully iridescent character, falling off one after the other. The same kind of chan^
is seen on the windows of our ancient churches.
The brittleness of unannealed glass by change of temperature is sometimes -very
great This defect may be corrected by slowly heating the Tessel in salt-water
or oil to the highest pitch consistent with the nature of these liquids, and letting
it cool rery slowly. Within the limits of that range of heat, it will, in conse-
quence of this treatment, bear alternations of temperature without cracking.
It has been said that glass made ftom silica and alkalies alone, will not resist the
action of water, but that the addition of a little lime is necessary for this effect.
In general 100 parts of quartzose sand require S3 parts of dry carbonate of soda
for their yitrification, and 45 parts of dry carbonate of potash. But to make un-
changeable alkaline glass especially with potash, a smaller quantity of this than the
above should be used with a very violent heat A small proportion of lime increases
the density, hardness, and lustre of glass ; and it aids in decomposing the alkaline
sulphates and muriates always present in the pearlash of commerce. From 7 to 20
parts of dry slaked lime have been added for 100 of silica, with advantage, it is
said, in some German glass manufactories, where the alkaline matter is soda ; for
potash does not assimilate well with the calcareous earth.
In many glass works on the continent, sulphate of soda is the form under "which
alkaline matter is introduced into glass. This salt requires the addition of 8 per
cent, of charcoal to decompose and dissipate its acid ; a result which takes place at a
high heat, without the addition of any lime. 88 pounds of quartz-sand, 44 pounds of
dry glauber salt, and S pounds of charcoal, properly mixed and fused, afford a
limpid, fluent, and workable glass; with the addition of 17 pounds of lime, these
materials fuse more readily into a plastic roass^ If less carbon be added, the fusion
becomes more tedious.
By a proper addition of galena (the native sulphuret of lead) to glauber salt and
quartz sand, without charcoal, it is said a tolerably good crystal g:lass may be formed.
The sulphuric acid of the salt is probably converted by the reaction of tne sulphuret
of lead into sulphurous acid gas, which is disengaged.
One atom of sulphuret of leads 1495*67, is requisite to decompose 3 atoms of
sulphate of soda » 2676. It is stated, on good authority, that a good colourless glass
may be obtained by using glauber salt wi&out charcoal, as by the following formula.
Qoartz sand - - - loo pounds I Lime - - • • 20 pounds
Calcined glauber salt - 20 „ | CuUet of soda glass • 12 „
The melting heat must be continued for 26^ hours. A small quantity of the sand
is reserved to be thrown in towards the conclusion of the process, in order to flu;iUtate
the expulsion of air bubbles. The above mixture will bear to be blanched by the
addition of manganese and arsenic The decomposition of the salt is in this case
effected by the lime, with which the sulphuric acid first combines, which is then con-
verted into sulphurous acid, and dissipated. Glass made in this way was found by
analysis to consist of 79 parts of silica, 12 lime, and 9*6 soda, without any trace of
gypsum or sulphuric acid.
Glauber salt is partially volatilised by the heat of the furnace, and acts upon the
arch of the oven and the tops of the pots. This is best prevented by introducing at
first into the pots the whole of the salt mixed with the charcoal, the lime, and one-
fourth part of the sand ; fusing this mixture at a moderate heat, and adding gradually
afterwards the remainder of the sand, increasing the temperature at the same time.
If we put in the whole ingredients together,'as is done with potash glass, the sand and
lime soon fall to the bottom, while the salt rises to the sui^e, and the combination
becomes difficult and unequal.
Sulphate of potash acts in the same way as sulphate of soda.
Muriate of soda also, according to Kim, may be used as a glass flux with advan-
tage. The most suitable proportions are 4 parts of potash, 2 of common salt, and 3 of
lime, agreeably to the following compositions.
1. 2.
Quartz sand .... 60*0 57*1
Calcined carbonate of potash - 17*8 19*1
Common salt .... 8*9 9*5
Lime 13*3 143
GLASS.
345
For Na 1, the melting heat most bo 10 hoars, which turns out a rery pure, solid,
good glass ; for No. 2, 23 hours of the furnace are required. Instead of the potash,
glauber salt may be substituted ; the proportions being then 19-1 glauber salt, 9-5
muriate of soda, 14*3 lime, 57*1 sand, and 1*3 charcoal
The oxide of lead is an essential constituent of the denser glasses, and may be re-
garded as replacing the lime, so as to form with the quartz-sand a silicate of lead. It
assimilates best with purified pearlash, on account of the freedom of this alkali from
iron, which is present in most sodas.
Its atomic constitution may be represented as follows :
Silicic acid ...
Oxide cf lead ...
Potash - - - .
Oxides of iron and manganese
5 atoms « 2877*0
1 « 1394-5
1 - 5900
Computation.
Analysis.
59-19
28-68
1213
59 20
28-20
9 00
1 40
4861*5
10000
97-80
The abore analysis by Berthier relates to a specimen of the best English crystal
glass, perfectly colourless and free from air-bubbles. This kind of glass may, how-
eyer, take several different proportions of potash and silica to the oxide of lead.
The composition of mirror-pUite> as made on the Continent, is as follows : —
White quartZ'Sand .*-... 300 pounds
Dry carbonate of soda «..-•- 100
Lime slaked in the air - - - - - 43
Gullet, or old glass ..... 300
The manganese should not exceed one half per cent, of the weight of soda.
Optical glass requires to be made with yery peculiar care. It is of two different
kinds ; namely, erown glass andjlint glass. The latter contains a considerable pro-
portion of lead, in order to give it an increased dispersive power upon the rays of
light, in proportion to its mean refractive power.
Optical crown glass should be perfectly limpid, and have so little colour, that a
pretty thick piece of it may give no appreciable tinge to the rays of light. It should
be exempt from strise or veins as well as air-bubbles, and have not the slightest
degree of milkiness. It should, moreover, preserve these qualities when worked in
considerable quantities. Potash is preferable to soda for m wng optical crown glass,
because the latter alkali is apt to make a glass which devitrifies and becomes
opalescent, by long exposure to heat in the annealing process. A simple potash silicate
would be free from this defect, but it would be too attractive of moisture, and apt to
decompose eventually by the humidity of the atmosphere. It should, therefore, con-
tain a small quantity of lime, and as little potash as suffices for making a perfect
glass at a pretty high temperature. It is probably owing to the high heats used in
the English crown glass works, and the moderate quantity of alkali (soda) which is
employed, that our crown glass has been found to answer so well for optical purposes.
The following recipe for crown glass is excellent : —
6 atoms of silica (2J?) 80
1 carbonate of soda ..... 54
5 silica .•- - - - - - -80
1 carbonate of lime - - - - - 50
1 atom of carbonate of baryta - - - 98
5 atoms of silica - - * - - - - 80
Silicates of lime and baryta jyer se, or even combined, are very refractory ; but they
vitrify well along with a third silicate, such as that of soda or potash.
The following are additional recipes for making different kinds of glass.
1. Bottle glass, — 11 pounds of dry glauber salts ; 12 pounds of soaper salts : a half
bushel of waste soap ashes; 56 pounds of sand; 22 pounds of glass skimmings; 1
cwt of green broken glass ; 25 pounds of basalt ThiiB mixture affords a dark green
glass.
2. Tellow or white sand, 100 parts ; kelp, 30 to 40; lixiviated wood ashes, from 160
to 170 parts ; fresh wood ashes, 30 to 40 parts ; potter's clay, 80 to 100 parts ; cullet
or broken glass, 100. If basalt be used, the proportion of kelp may be diminished.
In two l^tle-glass houses in the neighbourhood of Valenciennes, an unknown in-
346 GLASa
gredient, sold bj a Belgian, was employed, which he called jpar. This was discovered
by chemical analysis to be sulphate of baryta. The glass-makers observed that the
bottles which contained some of this substance were denser, more homogeneous, more
fusible, and worked more kindly, than those formed of the common materials ^l^hen
one prime equivalent of the silicate of baryta™ 123, is mixed with three primes of the
silicate of soda » (3 x 77*6) 232*8, and exposed in a proper furnace, vitrifieatioiL
readily ensues, and the glass may be worked a little under a cherry-red heai, with as
much ease as a glass of lead, and has nearly the same lustre.
3. Green window glasa^ or broad gloMs, — 1 1 pounds of dry glauber salt ; 10 poonds
of soaper salts ; half a bushel of lixiviated soap waste ; 50 pounds of sand \ 22 pounds
of glass pot skinmiings; 1 cwt of broken green glass.
4. Crown glass. — 300 parts of fine sand ; 200 of good soda ash ; 33 of lime ; from
150 to 300 of broken glass ; 60 of white sand i 30 of purified potash ; 15 of sal^ietne
(1 of borax); ^ of arsenious acid.
5. Nearly white table glass. — 20 pounds of potashes; 11 pounds of dry glauber salts;
16 of soaper salt; 55 of sand; 140 of cullet of the same kind. Another. — 100 of
sand ; 235 of kelp ; 60 of wood ashes ; IJ of manganese ; 100 j9f broken glass.
6. White table glass. — 40 pounds of potashes ; 1 1 of chalk ; 76 of sand ; ^ of man-
ganese ; 95 of white cullet.
Another. — 50 of purified potashes ; 100 of sand ; 20 of chalk ; and 2 of saltpetre.
Bohemian table or plate glass is made with 63 parts of quartz ; 26 of purified pot-
ashes ; 1 1 of sifted slaked lime, and some cullet
7. C>y«(a/^/aM.— 60 partsof purified potashes; 120 of sand; 24 of chalk; 2 of
saltpetre ; 2 of arsenious acid ; -fg of manganese.
Another. — 70 of purified pearl ashes ; 120 of white sand ; 10 of saltpetre ; ^ of
arsenious acid ; \ of manganese.
A third. — 67 of sand ; 23 of purified pearl ashes : 10 of sifted sUked lime ; ) of
manganese ; (5 to 8 of red lead).
A fourth. — 120 of white sand; 50 of red lead; 40 ofpurified pearl ashes; 20 of salt-
petre ; J of manganese.
A fifth. — 120 of white sand ; 40 of pearl ashes purified ; 35 of red lead ; 13 of salt-
petre ; A of manganese.
A sixth. — 30 of the finest sand ; 20 of red lead ; 8 of pearl ashes purified ; 2 of salt-
petre ; a little arsenious acid and manganese.
A seventh. — 100 of sand ; 45 of red lead ; 35 of purified pearl ashes ; \ of manga-
nese ; 4 of arsenious acid.
8. Plate glass. — Very white sand, 300 parts ; dry pnrified soda, 1 00 parts ; carbonate
of lime. 43 parts ; manganese, 1 ; cullet, 300.
Another. — Finest sand, 720 ; purified soda, 450 ; quicklime, 80 parts ; saltpetre, 25
parts ; cullet, 425.
A little borax has also been prescribed ; much of it communicates an exfoliating
property to glass.
Practical Details uf the Manufacture of Glass.
There are five different species of glass, each requiring a peculiar mode of fabrica-
tion, and peculiar materials : — 1. The coarsest and simplest form of this mannfhcture is
botde glass. 2. Next to it in cheapness of material may be ranked broad or spread
window glass. An improved article of this kind is now made near Birmingham,
under the name of British or German plate. 3. Crown glass comes next, or window
glass, formed in large circular plates or discs. This glass is peculiar to Great Britain.
4. Flint glass, crystal glass, or glass of lead. 5. Plate or fine mirror glass.
The Pots. — The materials of every kind of glass are vitrified in pots made of a
pure refhictory clay ; the best kind of which is a species of shale or slate clay dag
out of the coal-formation near Stourbridge. It contains hardly any lime or iron, and
consists of silica and alumina in nearly equal proportions. The masses are carefully
picked, brushed, and ground under edge iron wheels of considerable weight, and
sifted through sieves having 20 meshes in the square inch. This powder is moistened
with water (best hot), and kneaded by the feet or a loam-mill into an uniform smooth
paste. A large body of this dough should be made up at a time, and laid by in a damp
cellar to ripen. Previously to working it into shapes, it should be mixed with about
a fourth of its weight of cement of old pots, ground to powder. This mixture is
sufficiently plastic, and being less contractile by heat, forms more solid and durable
vessels. Glass-house pots have the figure of a truncated cone, with the narrow end
undermost ; those for bottle and window-glass being open at top, about 30 inches
diameter at bottom, 40 inches at the mouth, and 40 inches deep ; but the flint-glass
pots are covered in at top with a dome-cap, having a mouth at the side, by which the
GLASS. 347
zn&terials are introdaeed, and the glass is extracted. Bottle and crown-hoose pots are
from 3 to 4 inches thick ; those for flint-houses are an inch thinner, and of propor-
tionally smaller capacity. See Clat.
The well-mixed and kneaded doagh is first worked apon a hoard into a cake for
the bottom ; over this the sides are raised, by laying on its edges rolls of clay abore
each other with mnch manual labour, and careful condensation. The clay is made
into lumps, is equalised, and slapped much in the same way as for making pottery.
The pots thus fashioned must be dried very prudently, first in the atmospheric tem-
perature, and finally in a stove floor, which usually borrows its heat directly from the
glass-house. Before getting the pots in the furnace, they are annealed during 4 or 5
days, at a red heat in a small reverberatory vault, made on purpose. When com-
pletely annealed, they are transferred with the utmost expedition into their seat in the
fire, by means of powerful tongs supported on the axle of an iron- wheel carriage
£rame, and terminating in a long lever for raising them and swinging them round.
The pot'sefting is a desperate service, and when unskilfully conducted without due
mechanical aids, is the forlorn hope of the glass-founder.
t. The glass-houses are usually built in the form of a cone, from 60 to 100 feet high,
and from 50 to 80 feet in diameter at the base. The furnace is constructed in the
centre of ihe area, above an arched or groined gallery which extends across the whole
space, and terminates without the walls, in large folding doors. This cavern most
be sufficiently high to allow labourers to wheel out the cinders in their barrows,
Tlie middle of the vaulted top is left open in the building, and is covered •ver with
the grate-bars of the furnace.
1. Bottle glass, — The bottle-house and its furnace resemble nearly Jig. 895. The
furnace is usually an oblong square chamber, built of large fire-bricks, and arched
over with fire-stone, a siliceous grit of excellent quality extracted from the coal
measures of Newcastle. This furnace stands in the middle of the area ; and has its
base divided into three compartments. The central space is occupied by the grate-
bars : and on either side is th'e platform or fire-brick siege (seat), raised about 12
inches above the level of the ribs upon which the pots rest. Each siege is about 3
feet broiad.
In the sides of the furnace semi-circular holes of about a fbot diameter are left,
opposite to, and a little above the top of, each pot, called working holes, by which
the workmen shovel in the materials, and take out the plastic glass. At each angle
of the furnace there is likewise a hole of about the same size, which communicates
with the calcining furnace of a cylindrical form, dome-shaped at top. The flame
that escapes from the founding or pot-furnace is thus economically brought to rever-
berate on the raw materials of the bottle glass, so as to dissipate their carbonaceous or
volatile impurities, and convert them into a f^it A bottle-house has generally eight
other furnaces or fire arches ; of which six are used for annealing the bottles after they
are blown, and two for annealing the pots, before setting them in the furnace.
Generally, for common bottles, the common river sand and soap-boilers' waste are
used. About 3 parts of waste, consisting of the insoluble residuum of kelp mixed with
lime, and a little saline sabstance, are employed for 1 part of sand. This waste is first
of all calcined in two of the fire arches or reverberatories reserved for that^ purpose,
called the coarse arches, where it is kept at a red heat, with occasional stirring, from
24 to 30 hours, being the period of a journey, or joumie^ in which the materials could
be melted and worked into bottles. The roasted soap-waste is then withdrawn under of
the name of ashes, from its arch, coarsely ground, and mixed with its proper proportion
of sand. This mixture is now put into the fine arch, and calcined during the working
journey, which extends to 10 or 12 hours. Whenever the pots are worked out, that
frit is immediately transferred into them in its ignited state, and the founding process
proceeds with such despatch that this first charge of materials is completely melted
dovm in 6 hours, so that the pots might admit to be filled up a^in with the second charge
of frit, which is founded in 4 hours more. The heat is briskly continued, and in the
course of from 12 to 18 hours, according to the size of the pots, the quality of the fuel,
and the draught of the furnace, the vitrification is complete. Before blowing the
bottles, however, the glass must be left to settle, and to cool down to the blowing con-
sistency, by shutting the cave doors and feeding holes, so as to exclude the air from the
fire-grate and the bottom of the hearth. The glass or metal becomes more dense, and
by its subsidence throws up the foreign lighter earthy and saline matters in the form of
a scum on the surface, which is removed with skimming irons. The furnace is now
charged with coal, to enable it to afford a working heat for 4 or 5 hours, at the end of
which time more fuel is cautiously added to preserve adequate heat for finishing the
journey.
It is hardly possible to convey in words alone a correct idea of the manipulations
necessary to the formation of a wine bottle. Six people are employed at this ta^k ;
348
GLASS.
one, called a gatherer, dips the end of an iron tuhe, aboat five feet long, preTioiisIj
made red hot, into the pot of melted fnetal, turns the rod round so as to surround it with
glass, lifts it oat to cool a little, and then dips and tarns it round again ; and so in
succession till a ball is formed on its end sufficient to make the required bottle. He
then hands it to the blower, who rolls the plastic lump of glass on a smooth stone or
cast-iron plate, till he brings it to the very end of the tube ; he next introdaces the
pear-shaped ball into an open brass or cast-iron mould, shuts this together by pressing
a pedal with his foot, and holding his tube vertically, blows through it, so as to ex-
pand the cooling glass into the form of the mould. Whenever he takes his foot from
the pedal-lever, the mould spontaneously opens out into two halves, and falls asunder
by its bottom hinge. He then lifts the bottle up at the end of the rod, and transfers it
to the finisher, who, touching the glass-tube at the end of the pipe with a cold irooy
cracks off the bottle smoothly at its mouth-ring. The finished bottles are immediately
piled up in the hot annealing arch, where they are afterwards allowed to cool slowly
for 24 hours at least
2. Broad or spread window glass. — This kind of glass is called inferiorwindow glass
in this country, because coarse in texture, of a wavy wrinkled surface, and very cheap;
but on the continent spread window glass, being made with more care, is mnch
better than ours, though still far inferior in transparency and polish to crown glass,
which has, therefore, nearly superseded its use among us. But Messrs. Chance and Co.,
of Birmingham, make British sheet glass upon the best principles, and turn out an
article quite equal, if not superior, to anything of the kind made either in France or
Belgium. Their materials are those used in the crown-glass manufacture. The vitri-
fying mixture is fritted for 20 or 30 hours in a reverberatory arch, with considerable
stirring and paddling with long-handled shovels and rakes; and the frit is then trans-
ferred by shovels, while red hot, to the melting pots to be founded. When the glass is
rightly vitrified, settled, and brought to a working heat, it is lifled out by iron tubes,
blown into pears, which, being elongated into cylinders, are cracked up along one side
parallel to the axis, by touching them with a cold iron dipped in water, and are then
opened out into sheets. The glass cylinders are spread on a bed of smooth stone Paris-
plaster, or laid on the bottom of a reverberatory arch ; the cylinder being placed on its
side horizontally, with the cracked line uppermost, gradually opens out, and flattens
on the hearth. At one time, thick plates were thus prepared for subsequent polishing
into mirrors ; but the glass was never of very good quality ; and this mode of making
mirror-plate has accordingly been generally abandoned.
The spreading furnace or oven is that in which cylinders are expanded into tables
or plates. It ought to be maintained at a brisk red heat, to facilitate the softening of
the glass. The oven is placed in immediate connection with the annealing arch, so
that the tables may be readily and safely transferred from the former to the latter.
Sometimes the cylinders are spread in a large muffle furnace, in order to protect them
from being tarnished by sulphureous and carbonaceous fumes.
Fig. 890 represents a ground plan of both the spreading and annealing furnace; fig.
891 is an oblong profile in the direction of the dotted line :r T,fig, 890.
890
891
■/,./'
.">»7>
-Tif
nj
-X
a IS the fire-place ; h 5, the canals or flues through which the flame rises into both
^I^^T^ ' I' ® spreading furnace, upon whose sole is the spreading slab, rf, is the
ii?^ n^?K*"^""^*^'^^ ^"'^'^ ' * *• '^^""^ ^"8 ^liict extend obliquely across theanneal-
chln«Pi ;!*!!!> ^«!J.\for,'*e«ting the glass tables against during the cooling. //. the
warm^ fW ^h^ch the previously cracked cylbders are slid, so as to be^giidJally
iTte Ap nrni! ""^"'"Z '° >''® Spreading furnace, for enabling the workmen to regu-
raUimr n^o^S ' ^ ^ ^^^\ '° *^® anucalmg arch, for introducing the tools requisite for
raising up and removmg the tables. =» » © ^
892, at a,Tc^VTf^''^'"^^'^''* *° »teet glass, already described, is represented mfig.
GLASS. 84d
the Gre-jitaee itself ii divided into tbree compartmenUi vilh ■ middle tlab at ((which
is hollowed in the centre, fbr eoUectiDg bqj spill gUsa, aud two hearth tilei or slabs
■ ■ eiue the draught oi
holes ( e e are arches npon ,' *^^ f **^ .^iS^SsJ*
■which the bearing .lab. // A H ^ ^^'^.^T^^\
partly rest. Id the middle be- ^ /\ v^-^^ > l ' V"''l_L L ^
tween these archea, the flame
atrikes upwards npoo the pots
g g, placed as closely together
as pwtible for economy of
room. A ii the breast wall of
the fiimace ; i. Jig. 894, the
opening throngh which the
pots arc introduced; it is
bricked np aa soon aa they are
set. A * ia the bate of the
cooe or dome of Ibe furnace \
///.tbeworkingorificea, which \
are made Urger or smalleT ac' '
cording to tbe siie of the glaa
articlea to be made, m is tfai
flue which leads to tbe anneal
ing store ■, with an arche<
door. Eitertor to Ihll then
is usnally a drying kiln, not ahowD in the figure', and there are adjoining atoTcs,
called atcha, for drying and ennealing the new pots before they are set.
The cooling or annealing arch, or leer, is ofWo built independent of the glasi-houae
furuace, is then healed by a separate Ere-place, and conslnicted like a very long r«-
Terbpratory furnace.
The leer pans, or trays of aheet iron, are laid upon its bottom in an oblong aeries,
and hooked to each other.
3. CrDiTH-^/iui.^The crown-glass house with ill furnace is represented iojf;. 899,
where the bloaing operation is shown on the one sidt; of the figure, and thejIiuAinjr on
tbe other. The furnace is usnally constructed to receiie 4 or G pota, of auch dimen-
sions aa to make about a ton of glass each at a lime. There are, however, several
subsidiary fnmacca to a crown-Loose : 1, a reverberatory ftirnace or coJcor, for cal-
cining or ft'ltting the materials ) S,
a blowing furnace, for blowing the
pear-shaped balls made at the pot-
biiles, into large gUtbes, 3, a flaih-
ing fomace, and bottoming hole fbr
communicatiag a softening heat,
in expanding the globe into a cir-
cular plate i 4, the annealing arch
for the finished tables ; 5, the rever-
beratory oven for annealing the pot*
prior to their being set open tbe
fonodirg aifgf.
The materials of crown glaaa used
to be, fine sand, by measure 5 parts,
or by weight 10; ground kelp, by
measure II parta, or by weight 16^1
bat instead of kelp, soda ash i» now
generally employed. Prom 6 to
8 cwt. ta sand, lime, and soda-ash,
mixed together in wooden boxes
with a shovel, are thrown on the
sole of a large reverberatory. Here the mixture is well worked together with iron
paddles, fiat ahovels, and rakea with long batidles ; tbe area of this furnace being
about S feet square, and the height 2 feet. Tbe heat soon brings the materials to a
pasty conaiatence, when they must be diligently turned over, to favour the dissipation
of the carbon, sulphur, and other volatile matters of the kelp or soda ash, and to in-
corporate the fixed ingredients uniformly with the sand. Towards the end of 3 hours,
the fire is cooaiderably raised, and when the fourth hour has expired, the fritting
operation ia finished. Tbe mass is now shovelled or raked ont into shallow cast-iron
aquarc cases, smoothed down, and divided before it bardeos by cooling, into siinaro
lumps, by crusa sectiona with the spade. These frit-bricks are altemaids piled up
350
GLASS.
in & Inrge apartment for nie ; and have been Bappoud to imprare with age, bjr lb«
efflorescence ot their uline constituent! into c&rbooate of aoda on their mrfkce.
The fouDding-poti are filled up with these blocks of frit, and the farnaoc is power-
fullj urged hy opening all the subterranean passages to its grate, and elosiBg a]l titr
doors and windows of the glaas-bonse itself. After S or 10 hoon the vitrification has
made such progress, and the blocks first introduced are so tai melted down, that
another char^ of frit can be thrown in, and thus the pot is fed with fHt till the
proper quantity ii used, tn about 16 hours the vitriiicBtiou of the frit lui taken
place, and a considerable qosulity, amoonling often to the cwt of liquid saline matier
floats over the glass. This salt is caref\ill]r skimmed off into iron pots -with long
Udles. It is called Sandiver, or Glass-gall, and oonaisti utoajly of mariale of aodi,
with B little sulphate. Tbe pot is now ready for receiving IhG toppag o/cuUet, which
is broken pieces of window glass, to the amount of 3 or 4 cwL Tkus u shoT«Ued Jo
at short intervals; and Bs Its pressure forces up the residuary saline matter, tbic i>
removed ; for were it allowed to remain, the body of the glasa would be materuily
deteriorated.
The heat ia still continued for several hours till the glass is perfect, and the extri-
cation of gas called the boil, which accompaaies the fusion of crown glssa, baa neartj
terminated, when the fire is abated, by shutting up the lower vault doora and every
avenue to tbe grate. In order that the glass may settle fine. At tbe end of about 40
hours altogether, the fire being slightly raised by adding some coals, and opening the
doors, the glass is carefUly skimmed, and the working of tbe pots commeaceo.
„„. Before deacribing it. however, we may
' le that the marginal figure, 896, ahaws
hose oflhecrown-housecone, with tbe
Jfoor open pots in two rangea on opposite
■ sides of the furnace, sitting on their raiaed
P lUget, at each side of the grate. At oae
side of the base tbe door of the vault it
shown, and ill eoune is marked by the
dotted lines.
The cTown-g^ass fumace, j!^. 897, SdS, is an oblODg square, built in the c(
brick cone, largo enough to contain within it two or three pots at each aide of the
GLASS.
351
froot elevation of a six-pot famaee. 1, 2, S^fy. 897, are the working holes for the
purposes of rentilation, of putting in the materials, and of taking oat the metal to be
wToaght 4, 5, 6, 7, are pipe holes for warming the pipes before beginning to work
^ith them. 8, 9, 10, are foot holes for mending the pots and sieges. 11 is a bar
, of iron for binding the furnace, and keeping it from swelling.
The arch is of an elliptic form ; though a barrel arch, that is, an arch shaped like
the half of a barrel cut longwise through the centre, is sometimes used. But this soon
giTes way when used in the manufacture of crown glass, although it does yerj well
in the clay-furnace used for bottle houses.
The best stone for building ftimaces is fire-stone; it may be obtained in the
neighbourhood of Newcastle from the coal-measures generally, and some of the
sandstones of the eastern counties are found to answer the purpose admirably. The
great danger in building fhmaces is, lest the cement at the top should give way with
the excessiye heat, and by dropping into the pots, spoil the metal. The top should
therefore be built with stones only, as loose as they can hold together after the centres
are removed, and without any cement whatever. The stones expand and come quite
elose together when annealing ; an operation which takes from eight to fourteen days
at mosL There is thus less risk of any thing dropping firom the roof of the furnace.
The inside of the square of the furnace is built either of Stourbridge fire-clay an-
nealed, or of fire-stone, to the thickness of sixteen inches. The outside is built of
common brick, about nine inches in thickness.
The furnace is thrown over an ash-pit, or cave as it is called, which admits the
atmospheric air, and promotes the combustion of the Aimace. This cave is built of
stone until it comes beneath the grate room, when it is formed of fire-brick. The
abutments are useful for binding and keeping the furnace together, and are built of
masonry. The furnaces are stoutly clasped with iron all round, to keep them tight.
In four-pot furnaces this is unnecessary, provided there be four good abutments.
Fig. 899 is an elevation of the flashiog furnace. The outside is built of common
bricky the inside of fire-brick, and the mouth or nose of Stourbridge fire-clay.
899
900
901
I K L
Fig. 900 is the annealing kiln. It is built of common brick, except round the
grate room, where fire-brick is used.
Few tools are needed for blowing and flashing crown-glass. The requisite ball of
plastic gbss is gathered, in successive layers as for bottles, on the end of an iron tube,
and rolled into a pear-shape, on a cast-iron plate ; the workman taking care that the
air blown into its cavity is surrounded with an equal body of glass, and if he perceives
any side to be dicker than another, he corrects the inequalitv by rolling it on the slop-
ing iron table called marver (marbre). He now heats the bulb in the fire, and rolls it so
as to form the glass upon the end of the tube, and by a dexterous swing or two he
lengthens it, as shown in J^fig. 901. To extend the neck of that pear, he next rolls it
over a smooth iron rod, turned round in a horixontal direction, into the shape M^Jig. 901.
By further expansion at the blowing (timaoe, he now brings it to the shape l, repre-
sented in^^. 901.
This spheroid having become cool and somewhat stiff, is next carried to the bottom-
ing hole (like>^. 899), to be exposed to the action of flame. A slight wall erected
before one half of this hole, screens the workman from the heat, but leaves room for
the globe to pass between it and the posterior wall. The blowing-pipe is made to
rest a little way from the neck of the globe, on a hook fixed in the front wall ; and
thus may be made easily to revolve on its axis, and by giving centrifugal force to the
globe, while the bottom of it, or part opposite to the pipe, is softened by the heat, it
soon assumes the form exhibited m m,^;^. 901.
In this state the flattened globe is removed ftom the fire, and its rod being rested
on the cosher box covered with coal cinders, another workman now applies the end of
852 GLASS.
K solid iroD rod tipped vith melted glut, called a pmlo, to the nipple or promineixw
in the middle ; and tbn« attaches it to the centre of the ^lobe, while the lint work-
man cracki off the globe b; tonching its tubular neck with an iron chisel dipped in
cold water. The workman having thereby taken posseSEion of the globe bf its
bottom or knobbled pole attachiid to his pnnty rod, be now carrjei il to knolber cir-
cular opening, where he eiposea it lo the action of moderate flame with regnUr ron.-
tion, and thus slowlf hesta the thick projecting remains of the former neck, mnd
opens it slighLlj out. an shown at M, in^. 901. He oext hands it to the fioMhtr, -who,
resting the iron rod in a book placed near the side of the orifice ^fig. 899, whe«ls il
rapidly round opposite to a powerful flame, till itasanmea first the figure o,uid fioallj
that of a flat circular table.
The flasher theo walks off with the table, keeping up a slight rolation u he idotm
along, and when it is sufficientlj cool, he tami down his rod into a vertical position,
and lays the table flat on a drj block of fire-claj, or bed of sand, when in aHiatant
nips it off from the piato with a pair of long iron shears, or cracki it off with a touch
of cold iron. The loose table or ptale is lastly lifted up hoiizontally on m. double
pronged iron fork, introduced into the annealing arch, j^. 900, and raised on edge ; an
assistant with a long-kneed fork preventing it from &lliag too rapidly backwards.
In this arch a great many tables of glass are piled up in iron frames, and slowly
coaled from a heat of about SOO" to 100' F,, which takes about S-1 hours; whirn tbey
are removed. A circular plate or tabic of about 5 feet diameter weighs on an aTerage
4. Flint glati, — This kind of glais it to called because originally made with cal-
cined flints, as the siliceous ingredienL The materials at present employed in this
coonlry for the finest flint glass are, first, sand, calcined, sifted, and washed ; aecoikd,
an oxide of lead, either red lead or litharge ; and third, peaj-lash. Sand for flint
glaxs manu&cture is obtained from the Isle of Wight, Aylesbury, the New Foretl,
and some other localities in this country. A very beanlifiil land is brought from
America, and some has been sent home from Auslialia. The pearl ash of commerce
must however be purified by digesting it in a very iitlle hot water, which diEsolves
the carbonate of potash, and leaves the foreign salts, chiefly sulphate of potash.
muris.te of potash, and muriate of soda. The loluliou of the carbonate being allowed
to cool and become clear in lead pans, is'tben rno off into a shallow iron boiler, and
evaporated to dryness. Nitre is generally added as a fourth ingredient of the body
of the glass ; and il serves to correct any imperfect ions which miRht arise from acei-
dental combustible particles, or from the lend being not duly oxidised. The above
four sultstances coustltote the main articles ; to which we may add arsenic and man-
ganese, inlroduced in very small quanlilies, to purify the colour and clear np the
transparency of the glass. The black oiideof manganese, when used in such quantity
only as to peroxidise the iron of the sand, simply removes the green tinge caused by
the protoxide of iron ; but if more manganese he added than accomplishes that
purpose, it will give a purple tinge to the glass. The arsenic is supposed to connier-
act the injury arising from excess of manganese, but is itself very apt on the other
9fl2 hand to communicale some degi*«
of opalescence, or at least to im-
pair the lustre of the glasa.
The raw materials of flint glass,
are always mixed witb about a
third or a fourth of iheir weight
of broken glass of like qnilily;
thii mixture is thrown into the
added whenever the preceding
portions by melting subside; the
object being to obtain a pot full of
glass, to facilitate the skimmiog
off the impurities and sandiver.
I The month of the pot is now shut,
by applying clay-lute round the
stopper, with the exception of a
I small orifice below, for the escape
' glass requires about 48 hours for
its complete vitrificalion. though
the materials are more fusible than
those of crown glass ; in coDsequencc of (he contents of the pot being partially screeocd
by itscoverfyom the action of the fire, ai alsofrom the lower iotensity of the heat,
GLASS. 853
Fig. 90S Kprecents a flint glass house for 6 pots, with the arch or leer on one side for
annealing the crystal ware. In fig, 903, the base of the cone is seen, and the glass
pots i» situ on their platform ^q* ^
ranged roand the central fire grate. /^^ ^v
The dotted line denotes the con- nl/Cfc Cfc.ijk
tear of the fomacc^S^. 902. ^^^^-"^ PyrtP^^^^^^MiJi """"-""--^
Whenerer the glass appears fine, ^~~ " L^J'^'Mf^ -— ^
and is freed from its air bubbles, B|||n?7t~-^^ ^ "^*" ' '*^ _„-iniJSliljl
which it nsually is in about 36 ^^^^£", F^i"' """"'Z-ir""'"""' ''TfJMr''
hoars, the heat is suffered to fall % -l,: "_v2\ "" H 'iiji^'^^'^
a little by closing the bottom yaWes, -^^s^
&c, that the pot may settle ; but prior to working the metal, the heat is somewltat
nuMcf again.
It would be useless to describe the manual operations of fashioning the varions
articles of the flint-glass manufacture, because they are indefinitely varied to suit the
eonveniences and caprices of human society.
Every different flint-house has a peculiar proportion of glass materials. The fol-
lowing hare been offered a« good practical mixtures : —
1. Fine white sand ........ 300 parts.
Bed lead or litharge - .--.... 200
Refined pearl ashes ........go
Nitre - ..--20
Arsenic and manganese, a minute quantity.
3. Rne sand 50-5
Litharge -..-------. 27*2
Refined pearl ashes (carbonate of potash, with 5 per cent, of water) 1 7*5
Nitre ..-.---.-.-4.8
100*0
To these quantities from 80 to 50 parts of broken glass or cuUet are added, with
about a two-thousandth part of manganese, and a three-thousandth part of arsenic
Bnt manganese yaries so extremely in its purity, and contains often so much oxide of
iron, that nothing can be predicated as to its quantity preyiously to trial.
M. Payen, an eminent manufacturing chemist in France, says that the composition
of ''crystal " (the name given in France to their finest flint glass) does not deviate much
from the following proportions : —
Wood fire. Coal Are.
Siliceous sand .... 8 3
Minium ..... 2 S^
Carbonate of potash - - - Ij 1}
The flint-glass leer for annealing glass, is an arched gallery or large flue, about 36
feet long, 3 feet high, 4 wide ; havmg its floor raised above 2 feet above the ground of
the glass-honsel The hot air and smoke of a fire-place at one end pass along this gal-
lery, and are discharged by a chimney 8 or 10 feet short of the other end. On the floor
of the vault, large iron trays are laid and hooked to each other in a series, which are
drawn from the fire end towards the other by a chain, wound about a cylinder by a
winch handle projecting through the side. The flint-glass articles are placed in their
hot state into the tray next the fire, which is moved onwards to a cooler station when-
ever it is filled, and an empty tray is set in its place. Thus, in the course of about 20
hours, the glasp advances to the cool end thoroughly annealed.
Besides colourless transparent glass, which forms the most important part of this
manuAbctnre, various coloured glasses are made to suit the taste of the public. The
opaline crystal may be prepared by adding to the above composition (No. 2) phos-
phate of lime, or well burnt bone-ash in fine powder, washed, and dried. The article
must be aa uniform in thickness as possible, and speedily worked into shape, with a
moderate heat Oxide of tin, puttg^powder, was formerly used for making opalescent
glass, bnt the lustre of the body was always impaired by its means.
Crystal vessels are made of which the inneraurface is colourless, and all the external
facets coloured. Such works are easily executed. The end of the blowing- rod must
be dipped first in the pot containing colourless glass, to form a bulb of a certain size,
which being cooled a little is then dipped for an instant into the pot of coloured glass.
The two layers are associated without intermixture ; and when Uie article is finished
in its form, it is white within and coloured without Fluted lines somewhat deeply
cut, pass through the coloured coat, and enter the colourless one ; so that when they
cross, their ends alone are coloured.
For some time past, likewise, various crystal articles have been exhibited in the
You II. A A
354 GLASS.
market with coloured enamel figures on their surface, or with white inemstations of a
silvery lustre in their interior. The former are prepared hy placing the enamel olgeet
in the brass mould, at the place where it is sought to he attached. The hulh of glaaa
being put into the mould, and blown while very hot, the small plate of enamel gets
cemented to the surface. For making the white argentine incrustations, small figures
are prepared with an impalpable powder of dry porcelain paste, cemented into a solid
by means of a little gypsum plaster. When these pieces are thoroughly dried, thej
are laid on the glass while it is red hot, and a large patch of yery liquid glass is placed
aboTC it, so as to encase it and form one body with the whole. In this way the in-
crustation is completely enclosed ; and the polished surface of the crystal which
scarcely touches it, gives a brilliant aspect, pleasing to the ere.
Optical Glass. — An uniform fiint-glass, free from strus, or wreath^ is much in
demand for the optician. It would appear that such an article was much more eom-
monly made by the English manufacturers many years ago, than at present ; and tliat
in improving the brilliancy of crystal glass they have injured its fitness for oonstroct-
ing optical lenses, which depends, not so mucn on its whiteness and lustre, as on its
homogeneous character. Even a potful of pretty uniform glass, when it stands some
time liquid, becomes eventually unequable hj the subsidence of the denser portions ;
so that strie and gelatinous appearances beg^n to manifest themselves, and the gfaas
becomes of little value. Glass allowed to cool slowly in mass in the pot is particularl j
full of wreath, and if quickly refrigerated, that is in two or three hoars, it is apt to
split into a multitude of minute splinters, of which no use can be made. For optical
purposes, the glass must be taken out in its liquid state, being gathered on the end of
the iron rod from the central portion of a recently skinuned pot, after the upper layers
have been worked off in general articles.
M. Guinand, of Brenets near Neufchatel, a workman in the watch and clock trade,
appears to have discovered processes that furnished almost certainly pieces of fiint
glass capable of forming ^ood lenses of remarkable dimensions, even of 11 inches
diameter, of adequate density and transparency, and nearly f^ from s<rue. Guinand's
plan consisted mainly in thoroughly mixing the melted '* metal " with an iron rod.
Guinand joined M. Frauenhoffer, of Munich, and one of the largest of the lenses pro-
duced by them, the diameter of which is 9 inchesi is now in the observatory at Dmrpat.
Guinand was long in communication with the Astronomical Society of London ;
and he sent over some discs of flint-glass, of which Messrs. DoUond and Herschel
made a favourable report A commission was formed, consisting of Herschel, DoUond,
Faraday, and Roget, but owing to the annoying interferences of the excise offioersy
notwithstanding the Government had made some special exceptions in favour of those
scientific expenments, the results were not practically of that high value which might
have been expected. Many of the observations however were of great value. Amongst
other discoveries might be named the remarkable heavy glass, the Silico-horate o/Uad^
with which the discovery of the "so-called" magnetisation of a ray of light was made.
M. Guinand died, and one of his sons worked with M. Bontemps, while the widow
and another son set up works in Switzerland. From their manufactory some examples
of lenses were sent to the Great Exhibition of 1851. M. Bontemps was in 1846 pre-
vailed upon to accept the invitation of Messrs. Chance Brothers and Ca to unite with
them in attempts they were then making to improve the quality of glass. They sue-
ceeded in producing discs of extraordinary dimensions in fiint of 29 inches diameter,
weighing two cwt, and of crown class up to 20 inches. Messrs. Chance, at the re-
commendation of the jury, were mduced to submit their disc of fiint*glass to the
operation of grinding, finishing, and other processes necessary in order to ascertain
the uniformity of its density throoghout, and its superior quality was fully established.
M. Maes of Clichy, near Paris, proposes to manufacture optical glass, with the
addition of barytes, magnesia, and oxide of zinc, in combination with boracic acid.
The glass manufactured by M. Maes is exceedingly beautiful, but the boracic acid
renders it very expensive. M. Cauchoix, the eminent French optician, says, that out
of ten object glasses, 4 inches in diameter, made with M. Guinand*s fiint-glass, eight
or nine turned out very good, while out of an equal number of object glasMs made of
the flint-glass of the English and French manufactories, only one, or two at most, were
found serviceable.
An achromatic object glass for telescopes and microscopes consists of at least two
lenses ; the one made with glass of lead, or fiint ghiss« and the other with crown glass;
the former possessing a power of dispersing the coloured rays relatively to its mean
refractive power much greater than the latter; upon which principle, the achromatism
of the image is produced, by re-uniting the different coloured rays into one focoa
Three plans have been prescribed for obtaining homogeneous pieces of optical glass:
1, to lift a mass of it in large ladles, and let it cool in them; 2, to pour it ont from
the pots into moulds ; 3, to allow it to cool in the pots, and afterwards to eat it off in
GLASS. 355
boritooUl itraU. The iMt method teldom nffbtd* piee«« of oaifonn demitj, aoteu
pecnlUr precantiooa bKva been adopted to lettle the flint glais in Dnilhrm atnta g
becawe ilt nuteriala an of tach noequal denail^, the oiide of lead having a gpe-
ciBc gniTitf of S, and lilica of S'T, that they are apt to ataod at iiregnlir heighli in
Oae main eanw of tbeie ineqaalitie* liei in the eoiutmction of tb« fomace, vhereby
the bottom of the pot if naually much leu healed than the npperpart. In a plate glaM
faroace the temperature of the top of the pot has been found to be 130° Wed gew., while
that of the bottom iriu only 110°, conalitnting a difference of no lesi than 2610° F.
The necesaarr eoiueqaeiice i> that the denser particles which labaide to the bottom
during the huion of the maleriali, and after the fint eitricatioa of the gasei, muM
remain there, not being dnly agitated by the eTpaniive tbrc« of calorie, acting from
belov apuraida.
The follovlng rnggeationi, dedaced from a coniideration of prineiplee, may pro-
bably lead to lome improrementi, if jndicionsly applied. The great object n to
coaatersct the tendency of the glan of lead to diatribule itulf ioto rtrota of different
deoiitie* ; which may be effected either bj mechanicBl agitalion or by applying the
greateat heat to the bottom of the pot. But howerer hamogcneoni the glaw may be
thereby made, its iDbseqnent separation into strata of different densities most be pre-
Tented by rapid oooling and aolidifioalion. As the deeper the pots, the greater is the
chance of uneqaal ^leciSc graTity in their contents, it would be advisable to make them
wider and shallower than those id use for making ordinary glasa. The intermixture
may be effected either by lading the glass out of one pot into another in the farnace,
and back again, with copper ladles, or by ttirring it np with a ronier, then allowing tt
to settle for a short lime, till it become* clear and free fWnn air bubble*. The pot
may now be remored fKnn the furnace, iu order to solidify its cootents in their ho-
monneoD* state i after which the giaM may be broken in pieces, and be perfected by
anhjecting it to a second fusion ; or what is easier and qoicker, we may form snilable
discs of glass withont breaking down the potfiil, by lifting it ont in flat copper ladle*
with iron ■'""*•«, and tranaferring the lamps after a little while into the annealing
leet.—Ure.
To render a polftil <^ glass homogeneous by agitation, is a most difflenlt taak, as
sa iron rod would diactdour it, and a copper rod would be apt to melt. An iron rod
sheathed in latnioated platinam would aaiwer well, but for iti expense. A (tone-
ware tnbe snpported within by a rod of iron, might also be employed for the purpoM
in careful hands ; the stirring being repeated scTeral times, till at last the g^aas ■■
mETered to stiffen a little by decrease of temperature^ It mast be then allowed to
•ettle and cool, after which the pot, being of imall dimensions, may be drawn out ol
the fire.
8. The second method of producing the desired nniformity of mixture, connstB
in applying a greater heat to the bottom than to the upper part of (he melting wit.
Fia. 904 represents in section a furnace contriTed to effect this object It is cylin-
dncaJ, and of a diameter no greater than to allow the flames
to play roond the pot, containing fh>m three to four cwts. of
vitreous aaalerials. x is the pot, resting upon the arched
grid i a, built of fire-bricks, whose apertures are wide
enough to let the fiamet rise freely, and strike the bottom
and sides of the TesseL From 1} to S feet nuder that arch,
the fuel prate c if is placed- a c are the two working open-
ings for mtrodnciuf; the materials and inspecting the progreit
of the fusion ; they must be closed with fire-tiles and luted
with fire-clay at the beginning of the process. At the back
of the furnace, oppoaila the mouth of the fire-place, there is
a door-way, which is bricked up, except upon occasion of |
putting in and taking out the pot The draoghl is regulated i
hj means of a ilide-plate, upon the mouth of the ash-pit^
The pot being heMed to the proper pitch, some purified pearl
ash, mixed with fully twice its weight of coloorless quarts
sand, is to be thrown into it, and after the complete fusion of '
(his mixture, the remuning part of the sand, along with the
oxide of lead (fine litharge), is to be strewn upon the inrftce.
Theae siliceous partioles in their decent serre to extricate
the sir from the mass. WheneTer the whole is fused, the
a complete uniformity
if the particles.
R be withdrawn, the two workiuj
356 GLASS.
the fire-place and asli-pit to admit free ingress to cooling carrents of air, so as to con-
geal the liqaid mass as quickly as possible ; a condition essential to the nnifonnity of
the glass. It may be worth while to stir it a little with the pottery rod at the com-
mencement of the cooling process. The solidified ^lass may be afterwards detached
by a hammer in conehoidal discs, which after chipping off their edges, are to be
placed in proper porcelain or stone-ware dishes, and exposed to a softening heat, in
order to gi^e them a lenticular shape. Great care must be taken that the heat thus
applied by the muffle furnace be yery equable, for otherwise wreathes might be verj-
readily reproduced in the discs. A small oven upon the plan of a baker's, is best
fitted for this purpose, which being heated to duU redness, and then extinguished, is
ready to soften and afterwards anneal the conehoidal pieces.
Guinand's dense optical flint glass, of specific gravity 3*616, consists, by analpis, of
oxide of lead, 43*05 ; silica, 44*3 ; and potash, 11*75 ; but requires for its formatioD tlie
following ingredients : — 100 pounds of ground quartz ; 100 pounds of fine red lead ; 35
pounds of purified potash ; and from 2 to 4 pounds of saltpetre. As this species of
glass is injured by an excess of potash, it should be compounded with rather a defect
of it, and melted by a proportionably higher or longer heat. A good optical glass
has been made in 'Germany with 7 parts of pure r^ lead, 3 parts of finely groond
quartz, and 2 parts of calcined borax.
5. Plate ylcus. — This, like English crown-glass, has a soda flux, whereas flint-glass
requires potash, and is never of good quality when made with soda. We shall distri-
bute our account of this manufacture under two heads.
1. The different furnaces and principal machines, without whose knowledge it would
be impossible to understand the several processes of a plate-glass factory.
2. The materials which enter into the composition of this kind of glass, and the
series of operations which they undergo ; devoting our chief attention to the changes
and improvements which long experience, enlightened by modem chemistry, has intro-
duced into the great manufactory of Saint-Gobain in France, under the direction of
M. Tassaert. It may however be remarked that the English plate-glass mannfactore
derives peculiar advantages from the excellence of its grinding and polishing ma-
chinery.
The following description given by Dr. Ure refers almost entirely to the manofiie-
ture of plate glass in France. It is retained in nearly its original form, and is, in
nearly all respects, equally applicable to the manufEtctuTe of the best plate glass io this
country.
The clay for making the bricks and pots should be f^ from lime and iron, and
very refractory. It is mixed with the powder of old pots passed through a silk sieve.
If dlie clay be very plastic it will bear its own weight of the powder, but if shorter in
quality, it will take only three-fifths. But before mingling it with the cement of old
pots, it must be dried, bruised, then picked, ground, and finally elutriated by agita-
tion with water, decantation through a hair sieve, and subsidence. The clay fluid after
passing the sieve is called dip (coulU).
The furnace is built of dry bricks, cemented with slip, and has at each of its fbor
angles a peculiar annealing arch, which communicates with the furnace interiorly, and
thence derives sufficient heat to effect in part, if not wholly, the annealing of the pots,
which are always deposited there a long time before they are used. Three of Uiese
arches, exclusively appropriated to this purpose, are called pot-arches. The fourth is
called the arch of ike materiaU, because it serves for drying them before they are founded.
Each arch has, moreover, a principal opening called the throat, another called bomnard^
by the French workmen, through which fire may be kindled in the arch itself^ when it
was thought to be necessary for the annealing of the pots ; a practice now abandoned.
The duration of a furnace is commonly a year, or at most 14 months ; that of the
arches is SO years or upwards, as they are not exposed to so strong a heat
In the manu&cture of plate-glass two sorts of crucibles are employed, called the
pots and the basins (cuvettes). The first serve for containing the materials to be
founded, and for keeping them a long time in the melted state. The cuvettes receive the
melted glass after it is refined, and decant it out on the table to be rolled into a plate.
Three pots hold liquid glass for six small basins, or for three large ones, the latter being
employed for makmg mirrors of great dimensions, that is, 100 inches long and up-
wards. Furnaces have been lately constructed with 6 pots, and 12 cuvettes, 8 of which
are small, and 4 large ; and cuvettes of three sizes are made, called smally middling^ and
large. The small are perfect cubes, the middling and the large ones are oblong pa-
rallelepipeds. Towards the middle of their height, a notch or groove, two or three
inches broad, and an inch deep, is left, called the girdle of the cuvette, by which part
they are g^rasped with the tongs, or rather are clamped in the iron fhime. This fhone
goes round the four sides of the small cuvettes, and may be placed indifferently upon
GLASS. 357
■11 their sides; in the other cayettes, the girdle extends only over the t^ro large sides,
because they cannot be turned up. See m T^fig. 905, p. 360.
The pot is an inverted truncated cone, like a crown glass pot It is about 30 inches
high, and from SO to 32 inches wide, including its thickness. There is only a few
inches of di£Perence between the diameter of the top and that of the bottom. The
bottom is three inches thick, and the body turns gradually thinner till it is an inch at
the mouth of the pot
The large building or factory, of which the melting furnace occupies the middle
space, is odled the haUe in French. At Kavenhead in Lancashire it is called the
foundry, and is of magnificent dimensions, its length is 339 feet, and its breadth 155.
The famous hoik of St Gobain is 174 feet by 120. Along the two side walls of the
haUe, which are solidly constructed of hewn stone, there are openings like those of
common ovens. These ovens, destined for the annealing of the newly cast plates,
bear the name of earqiiaiaet. Their soles are raised two feet and a half above the level
of the ground, in order to brin^ them into the same horizontal plane with the casting
tables. Their length, amountmg sometimes to 30 feet and their breadth to 20, are
required in order to accommodate 6, 8, or even 10 plates of glass alongside of each
other. The ihmt aperture is called the throat &>^d the back door the little throat
(gtteukiuy. The carquaise is heated by means of a fire-place of a square form called
a tisarf which extends along its side.
The founding or melting furnace is a square brick building laid on solid foundations,
being fkt>m 8 to 10 fieet in each of its fronts, and rising inside into a vault or crown
about 10 ftet high. At each angle of this square, a smsdl oven or arch is constructed,
likewise vaulted within, and communicating with the melting furnace by square flues,
called lunettes, through which it receives a powerful heat though much inferior to that
round the pots. The arches are so distributed as that two of the exterior sides of the
furnace stand wholly f^e, while the two other sides, on which the arches encroach,
offer a free space of only 3 feet In this inteijacent space, two principal openings of
the furnace, of equal size in each side, are left In the building. These are called
tunnels. They are destined for the introduction of the pots and the fueL
On looking through the tunnels into the inside of the furnace, we perceive to the
right hand and the left, along the two free sides, two low platforms or eieffeSt at least
30 inches in height and breadth. See figs, 896, 898.
These siegee (seats) being intended to support the pots and the cuvettes filled with
heavy materials, are terminated by a slope, which ensures the solidity of the fire-clay
mound. The slopes of the two sieges extend towards the middle of the furnace so
near as to leave a space of only from 6 to 10 inches between them for the hearth. The
end of this is perforated with a hole sufficiently large to give passage to the liquid glass
of a broken pot, while the rest is preserved by lading it from the mouth into the ad-
joining cuvette.
In the two large parallel sides of the furnace, other apertures are left, much smaller
than the tunnels, which are called ouvreaux (peep holes). The lower ones, or the
ouvreaux en bcu, caWedcuvette openings, because, being allotted to the admission of these
vessels, they are exactly on a level with the surface of the sieges, and with the floor of
the haUe. Plates of cast iron form the thresholds of these openings, and facilitate the
ingiress and egress of the cuvettes. The apertures are arched at top, with hewn stone
like the tunnels, and are 18 inches wide when the cuvettes are 16 inches broad.
The upper and smaller apertures, or the higher ouvreaux, called the lading holes, be-
cause they serve for transvasing the liquid glass, are three in number, and are placed
31 or 32 inches above the surface of the sieges. Ab the pots are only 80 inches high,
it becomes easy to work through these openings either in the pots or the cuvettes. The
pots stand opposite to the two pillars which separate the openings, so that a space is left
between them for one or more cuvettes according to the size of the latter. It is obvious
that if the tunnels and ourreaux were left open, the furnace would not draw or take the
requisite founding heat Hence the openings are shut by means of fire-tiles. These
are put in theii* places, and removed by means of two holes left in them in corre-
spondence with the two prongs of a large iron fork supported by an axle and two iron
wheels, and terminated by two handles which the workmen Lay hold of when they
wish to move the tile.
The closing of the tunnel is more complex. When it is shut or ready for the firing,
the aperture appears built up with bricks and mortar from the top of the aroh to the
middle of the tutmeL The remainder of the door-way is closed, — 1. on the two sides
down to the bottom, by a small upright wall, likewise of bricks, and 8 inches broad,
called walls of the glage ; 2, by an assemblage of pieces called pieces of the gUtye, be-
cause the whole of the closure of the tunnel bears the name ofglage. The upper hole,
4 mches square, is called the tisar, through which billets of wood are tossed into the
A A 3
858 GLASS.
fire. Fuel is also Introdaced into the posterior opening The fire is always kept ap
on the hearth of the tunnel, which is on this account, 4 inches higher than the funtace-
hearth, in order that the glass which may accidentally fall down on it, and which does
not flow off by the bottom hole, may not impede the combustion. Should a body of
glass, howeyer, at any time obstruct the grate, it must be remoyed with rakes, by open-
ing the tunnel and dismounting the fire-tile stoppers of the giaye.
Formerly wood fuel alone was employed for heating the melting-furnaces of the
mirror* plate manufactory of Saint-(xobain ; but within these few years, the director of
the works makes use with nearly equal advantage of pit-coaL In the same establishment,
two melting furnaces may be seen, one of which is fired with wood, and the other with
coals, without any difference being perceptible in the quality of the glass furnished by
either. It is not true, as has been stated, that the introduction of pit-coal has made it
necessary to work with coyered pots in order to avoid the discolouration of the materials,
or that more alkali was required to compensate for the diminished heat in the coyered
pots. They are not now covered when pit-coal is used, and the same success is ob-
tained as heretofore by leaving the materials two or three hours longer in the pots aad
the cuvettes. The construction of the furnaces in which coal is burned is the same
as that with wood, with slight modifications. Instead of the close bottomed hearth of
the wood furnace, there is an iron grate in the coal-hearth through which the air
enters, and the waste ashes descend.
When billets of wood were used as fuel, they were well dried beforehand, by being
placed a few days on a frame work of wood called the wheel, placed two feet aboTe
the furnace and its arches, and supported on four pillars at some distance firom the
angles of the building.
The progress of chemistry, the discovery of a good process for the mana&etare of
soda from sea salt, which furnishes a pure alkali of uniform power, and the certain
methods of ascertaining its purity, have rendered this department of glass-making fw
more certain than formerly. At Saint- Gobain no alkali is employed except artificial
crystals of soda, prepared at the manufactory of Chauny, subsidiary to that estab-
lishment. The first crop of soda crystals is reserved for the plate-glass manu&c-
ture, the other crystals and the mother- water salts are sold to the makers of inferior
glass.
If glass contains much lead it has a yellow tint If manganese is present it changes
by the action of light to a pale rose. Iron imparts a dull greenish tmt ; therefore the
proportions of all those materials should be adjusted with great care.
At the mirror-plate works of Ravenhead, near St Helen's in I^&ncashire, soda crys-
tals, from the decomposition of the sulphate of soda by chalk and coal, have been also
tried, but without equal success as at Saint-Gobain ; the failure being unquestionably
due to the impurity of the alkali. Hence, in the English establishment, the soda isob-
tained by treating sea-salt with pearl-ash, whence carbonate of soda and muriate of
potash result The latter salt is crystallised out of the mingled solution, by evapora-
tion at a moderate heat, for the carbonate of soda does not readily crystallise till the
temperature of the solution fall below 60^ Fahr. When the muriate of potash is thus
removed, the alkaline carbonate is evaporated to dryness.
Long experience at Saint- Gobain has proved that one part of dry carbonate of soda
is adequate to vitrify perfectiy three parts of fine siliceous sand, as that of the mound
of Aumont near Senlis, of Alum Bay in the Isle of Wight, or of Lynn in Norfolk. It
is also known that the degree of heat has a great influence upon the vitrification, and
that increase of temperature will compensate for a certain deficiency of alkali ; for it is
certain that a very strong fire always dissipites a c^d deal of the soda, and yet the glass
is not less beautifiU. The most perfect mirror-plate has constantiy afforded to M. Van-
quelin, in analysis, a portion of soda inferior to what had been employed in its fonna>
tion. Hence, it has become the practice to add, for every 100 parts of cullet or broken
plate that is mixed with the glass composition, one part of alkali, to make up fbr the
loss that the old glass must have experienced.
To the above mentioned proportions of sand and alkali, independentiy of the cullet
which may be used, dry slaked lime carefully sifted is to be added to the amount of
one seventh of the sand ; or the proportion will be, sand, 7 cwt ; quicklime, 1 cwt ;
dry carbonate of soda, 2 cwt and 37 lbs. ; besides cullet The lime improves the quality
of the glass ; rendering it less brittle and less liable to change. The preceding quan-
tities of materials, suitably blended, have been uniformly found to afford most advan-
tageous results. The practice formerly was to dry that mixture, as soon as it was
made, in the arch for the materials, but it has been ascertained that this step may be
dispensed with, and the small portion of humidity present is dissipated almost instantly
after they are thrown into the furnace. The coat of glaae previously applied to the
inside of the pot, prevents the moisture from doing them any harm. For this reason,
when the demand for glass at Saint-Gobain is very great, the materials are neither
GLASS. 359
Iritted itor eren dried, bat shorelled directly into the pot ; this is called fonitdiiig raw.
Six workmen are employed in shovelling- in the materials either fritted or otherwise,
for the sake of expedition, and to prevent the furnace getting cooled. One-third of
the mixture is introduced at first ; whenever this is melted, the second third is thrown
in, and then the last These three stages are called the first, second, and third fusion
or founding.
According to the ancient practice, the founding and refining were both executed in
the pots, and it was not till the glass was refined, that it was laded into the cuvettes,
where it remained only 3 hours, the time necessary for the disengagement of the air
bubbles introduced by the transvasion, and for giving the metal the proper consistence
for easting At present, the period requisite for founding and refining is equally
divided between the pots and the cuvettes. The materials are left 16 hours in the pots,
and as many in the cuvettes ; so that in 82 hours, the glass is ready to be cast. During
the last two or three hours, the fireman or tiseur ceases to add fael ; all the openings
are shut, and the glass is allowed to assume the requisite fluidity ; an operation called
Mtopping the glass, or performing the ceremony.
The transfer of the glass into iheeuvettes^ is called hiding {tr^etage). Before this is
done, the cuvettes are cleared out, that is, the glass remaining on their bottom is re-
moved, and the ashes of the firing. They are lifted red hot out of the furnace by the
method presently to be described, and placed on an iron plate, near a tub filled
with water. The workmen, by means of iron paddles 6 feet long, flattened at one end
and hammered to an edge, scoop out the fluid glass expeditiously, and throw it into
water ; the cvvettet are now returned to the furnace, and a few minutes afterwards the
lading begins.
In this operation, ladles of wrought iron are employed, fiimished with long handles,
which are plunged into the pots through the upper openings or lading holes, and
immediately transfer their charge of glaas into the buckets. Each workman dips his
ladle only three times, and empties its contents into the cuvette. By these three
immersions (whence the term trifeter is derived), the large iron spoon is heated so much
that when plunged into a tub fuU of water, it inakes a noise like the roaring of a lion,
which may be heard to a very great distance.
The founding, refining, and ceremony being finished, they next try whether the glass
be ready for casting. With this view, the end of a rod is dipped into the bucket, which
is called drawing tke glass ; the portion taken up being allowed to run off, naturally
assumes a pear-shape, from the appearance of which they can judge if the consistence
be proper, and if any air bubbles remain. If all be right, the cuvettes are taken out of
the furnace, and conveyed to the part of the haUe where their contents are to be poured
out. This process requires peculiar instruments and manipulations.
Ceuting, — While the glass is refining, that is, coming to its highest point of perfec*
lion, preparation is made for the most important process, the casting of the plate, whose
success crowns all the preliminary labours and cares. The oven or carquaise destined
to receive and anneal the plate, is now heated by its small fire or tisar to such a pitch
that its sole may have the same temperature as that of the plates, being nearly red-
hot at the moment of their being introduced. An unequal degree of heat in the
carquaise would cause breakage of the glass. The casting table is then rolled towards
the front door or throat, by means of levers, and its surface is brought exactly to the
level of the sole of the oven.
The table T^fig. 905, is a mass of bronze, or now preferably cast-iron, about 10 feet
long, 5 feet broad, and flrom 6 to 7 inches thick, supported by a frame of carpentry,
which rests on three cast-iron wheels. At the end of the table opposite to that next to
the front of the oven, is a very strong frame of timber-work, called the puppet or
standard, upon which the bronze roller which spreads the glass is laid^ before and
after the casting. This is 5 feet long by 1 foot in diameter ; it is thick in the metal
but hollow in the axis. The same roller can serve only for two plates at one casting,
when another is put in its place, and the first is laid aside to cool ; for otherwise the
hot roller would, at a third casting, make the plate expand unequally, and cause it to
crack. When the rollers are not in action, they are laid aside in strong wooden trestles,
like those employed by sawyers. On the two sides of the table in the line of its length,
are two parallel bars of bronze, t, t, destined to support the roller during its passage
fW>m end to end ; the thickness of these bars determines that of the plate. The table
being thns arranged, a crane is had recourse to for lifting the cuvette, and keeping it
suspended, till it be emptied upon the table. This raising and suspension are effected
by means of an iron gib, fiimished with pulleys, held horizontally, and which turns with
them.
The tongs, T^Jig. 905, are made of four iron bars, bent into a square frame in their
middle, for embracing the bucket Four chains proceeding from the comers of the
A a4
lationi of the eutinK. Tiro of Ibe m ^eh, and place qnicU; in ftont of one of the lower
opeuings, the anmll cuTette-carriage, which bears a forked 1>ar of iron, having two
proDgi correBpondiag lo the tvo boles left in Ibe fire-tile door. This fork, mo-ited
on the axle of two cast-iron wheels, extends al its other end into two branches ter-
minaled bv handles, b; which the workmen moTe the fork, lift out the tile stopper,
and set it down against the onter wall of the Airnace.
The instant these men retire, two others paih forward into the opening the extm-
mitjr of the tongs- carriage, so as to seiie the bucket b; the girdle or ratber to damp
it. At Ibe same time, a third workman is bns<r wim an iron pinch or long ehiiel,
detaching the bucket from its seat, lo which it often adheres by some spilt glut ;
whenever it is free, be withdraws it from Ibe fHimaoe. Two powerful brancbe* of
iron united by a holt, like two scissor bladea, which open, Come together, and Jdid b;
a quadrant near the other end, form the tongs-carriage, which is moonted npoA two
wheels like a truck.
The same description wiil appl^ almost wholly to the iron-plate carriage, on which
the bucket is hud the moment it is taken out of the furnace ; the only djmrence in its
construction is, that on the bent iron bars which form the tail or lower steps of this
csrriage (in place of the tongs) is permanently fastened an iron plate, on which the
bucket is placed and carried for the casting.
WheocTer the cuvetle is set upon ita carnage, it must be rapidly wheeled to its itaticn
near tbe crane. The tonga t above described are now apphed to the girdle, and are
then hooked upon the crane by the sospeosion chains. In this position the backet i*
skimmed by means of a copper tool called a aabre, because it has nearly the shape of
that weapon. Every portion of the matter removed by the sabre is thrown into a
copper ladle (pocht de gamiji), which is emptied from time to time into a oitlem of
water. Alter being skimmed, the backet is lifted up, and brushed very clean on its
sides and bottom ; then "bj the double handles of the suspension- tongs it is swung
round to the table, where it is seized by the workmeo appointed to turn it over ; the
roller having been previously laid on its ruler bars, near tbe end of the table which ii
in contact with the annealing oven. The ctiiw((«-men begin to poox oat towards (he
right extremity E of the roller, and terminate when it has arrived at the left extremity
c While preparing to do so, and at the instant of casting, two men place within the
ruler-bar on each side, that is, between the bar and the liquid glass, two iron instm-
ments called /landt, m m, m n, which prevent the glass from spreading beyond the
rulers, whilst another draws along the table the wiping bar c c, wrapp^ in linen, lo
remove dost, or any small objects which may interpose between the table and the
liquid glass.
Whenever the melted glass is poured out, two men spread it over the table, gnidiag
tbe roller slowly and steadily along, beyond tbe limits of the glass, and (hen nm it
smartly into the wooden standard prepared for its reception, in place of the trestles v v.
The empty bucket, while still red-hot. Is hnng again upon the crane, set on it* plale-
iron carriage, fVeed fh>m ita tongs, and replaced in the fnmace, to be speedily cleared
out anew, and charged with fresh fluid from the pots. If, while Uie roller glides alooa,
then ,-.-.-.. •,.....
GLASS. 861
sDsall portioDB of Mini-vitrified matter which foil ftom the Y4iilt of the fbmaoe, and
from their density occupy the bottom of the cuvettes.
While the plate is still red*hot and ductile, about 2 inches of its end opposite to the
car^uaue door is turned up irith a tool ; this portion is called the head of the muror;
a^nst the outside of this head, the shoyel, in the shape of a rake without teeth, is ap-
plied, with which the plate is eventually pushed into the oven, while two other work-
men press upon the upper part of the head with a wooden pole, eight feet long, to
preserve the plate in its borixontal position, and prevent its being warped. The plate
18 now left for a few moments near the throat of the car^iuaue, to give it soliditj ;
after which it is pushed further in by means of a very long iron tool, whose extremity
is forked like the letter y, and hence bears that name ; and is thereby arranged in the
most suitable spot for allowing other plates to be introduced.
However numerous the manipulations executed fh>m the moment of withdrawing
the ctivette from the furnace, till the cast-plate is pushed into the annealing oven, they
are all performed in less Aan five minutes.
When all the plates of the same casting have been placed in the carqucuse, it is
sealed up $ that is to say, all its orifices are closed with Aeeta of iron, surrounded and
made tight with plastic loam. With this precaution, the cooling soes on slowly and
equably in every part, for no cooling current can have access to the mterior of the oven.
After they are perfectly cooled, the plates are carefully withdrawn one after another,
keeping them all the while in a horizontal position, till they are entirely out of the
carquaise. As soon as each plate is taken out, one set of workmen lower quickly and
steadily the edge which they hold, while another set raise the opposite edge, till the
flass be placed upright on two cushions stuffed with straw, and covered with cauTas.
n this vertical position they pass through, beneath the lower edge of the plate, three
girths or straps, each four feet long, thickened with leather in their middle, and ending
in wooden handles ; so that one embraces the middle of the plate, and the other two
the ends. The workmen, six in number, now seize the handles of the straps, lift up
the glass closely to their bodies, and convey it with a regular step to the warehouse.
Here the head of the plate is first cut off with a diamond square, and then the whole is
attentively examined, in reference to its defects and imperfections, to determine the
sections which must be made of it, and the eventual size of the pieces. The parings
and small cuttings detached are set aside, in order to be ground and mixed with the
raw materials of another glass-pot.
The apartment in which the rooghing-down and smoothing of the plates is per-
formed, is ftimished with a considerable number of stone tables, truly hewn and placed
apart like billiard tables, in a horizontal position, about 2 feet above the ground.
They are rectangular, and of different sizes proportional to the dimensions of the
plates, which they ought always to exceed a little. These tables are supported either
on stone pillars or wooden frames, and are surrounded with a wooden board whose,
upper edge stands somewhat below their level, and leaves in the space between it and
the stone all round an interval of S or 4 inches, of which we shall presently see the uce.
A cast piate, unless formed on a table quite new, has always one of its &oes, the one
next the table, rougher than the other ; and with this facing the roughing-down begins.
With this Tiew, the smoother face is cemented on the stone table with Paris-plastar.
But often instesid of one plate, several are cemented alongside of each other, those of
the same thickness being carefully selected. They then take one or more crude
plates of about one*third or one-fourth the surface of the plate fixed to the table,
and fix it on them with liquid gypsum to the large base of a quadrangular truncated
pyramid of stone, of a weight proportioned to its extent, or about a pound to the
square inch. This pyramidal muller, if small sized, bears at each of its angles of the
upper &ce a peg or ball, which the grinders lay hold of in working it ; but when of
greater dimension, there is adapted to it horizontally a wheel of slight construction,
8 or 10 feet in diameter, whose circumference is made of wood rounded so as to be
seized with the hand. The upper plate is now rubbed over the lower ones, with
moistened sand applied between.
This operation is however performed by machinery. The under plate being fixed
or imbedded in stucco, on a solid table, the upper one likewise imbedded by the same
cement in a cast-iron fhime, has a motion of circumrotation given to it, closely resem-
bling that communicated by the human hand and arm, moist sand being supplied
between them. While an excentric mechanism imparts this double rotatory movement
to the upper plate round its own centre, and of that centre round a point in the lower
plate, this plate placed on a movable platform changes its position by a slow horizontal
motion, both in the direction of its length and its breadth. By this ingenious con-
trivance, which pervades the whole of the grinding and polishing machinery, a re-
markable regularity of friction and truth of surface is produced. When the pktes are
sufficiently worked on one face, they are reversed in the frames, and worked together
3G2 GLASS.
on the other. The Paris plaster is usually coloured red, in order to show any defects
in tiie glass.
The smoothing of the plates is effected on the same principles by the use of moist
emery irashed to soccessWe degrees of fineness, for the successive stages of the ope-
ration ; and the polishing process is performed by rubbers of hat-felt and a thin pa«te
of colcothar and water. The colcothar, called slso crocus, is red oxide of iron pre-
pared by the ignition of copperas, with grinding and elutriation.
The last part, or the polishing process, is performed by hand. This is managed by
females, who slide one plate over another, while a little moistened putty of tin finely
lerigated is thrown between.
Large mirror-plates are now the indispensable ornaments of every large and snmp-
tuous apartment ; they diffuse lustre and ^ety round them, by reflecting the rays of
light in a thousand lines, and by multiplymg indefinite! v the images of objects placed
between opposite parallel planes. For the process of silvering, see MntBORa.
Bohemian glass. — M. Peligot states that the hard glass of Bohemia is composed of
100 parts of sihca, 13 parts of quicklime, and only 28 parts of carbonate of potash.
These proportions give a glass qnite unmanageable in ordinary furnaces ; bat the ad-
dition of a comparatively small quantity of boracic acid is capable of determining
fusion, and the result is a glass having all the requisite limpidity at a high temperature,
and possessing at the same time a great brilliancy and hardness.
The Bohemian glass is, within certain limits, perfectly elastic, and very sonorous ;
when well made, it is sufficienUy hard to strike nre with steel, and is scratched with
difficuhv. The lead glasses, on the other hand, have but little hardness, and less in
proportion as they contain more oxide of lead ; besides which they rapidly lose their
brilliancy by use.
The silica which is employed in Bohemia in the manufincture of glass, is obtained by
calcining crystalline quartz, and afterwards pounding it while dry. When the quarts
has been heated to a cherry -red, it Is withdrawn from the fire, and thrown imme-
diately into cold water.
Almost all the Bohemian glass is a potash glass, because soda and its salts give to
glass a sensible yellowish tint The limestone which is used is«as white as Carrara
marble. The clay employed for the crucibles is very white, and consists of silica, 45|^;
alumina, 40<^, ; and water, 1 3^1.
The manufactore of glass in Bohemia is of very high antiquity, and the same pecu-
liarities have always belonged to the true Bohemian manufacture.
In our modem times the Bohemian glass has been more especially celebrated fbr
the beautiful varieties of colours which are produced. See Glass, coLouBBik
Venetian glass, — From an early date the city of Venice has been celebrated fbr
its glass ; the reticulated f^ss, the crackle glass, and the glass paper weights, or stt/Ze-
fiore., are all due to the Venetians.
The manufacture oi glass beads at Murano, near Venice, has been carried on for an
indefinite period, and Africa and Asia have been supplied from their glass-hoosesi Tlie
process is most ingeniously simple. Tubes of glass of every colour, are drawn out to
great lengths in a gallery adjoining the glass-house pots, in the same way as the more
moderate lengths of thermometer and barometer tubes are drawn in our glass-hooses.
These tubes are chopped into very small pieces of nearly uniform length on the op-
right ed^ of a fixed chisel. These elementary cylinders being then put in a heap
into a mixture of fine sand and wood ashes, are stirred about with an iron spatula till
their cavities get filled. This curious mixture is now transferred to an iron pan sus-
pended over a moderate fire, and continually stirred about as befbre, whereby the
cylindrical bits assume a smooth rounded form ; so that when removed from the fire
and cleared out in the bore, they constitute beads, which are packed in casks, and ex-
ported in prodigious quantities to almost ever^ country. See Gems, aruficiai..
The manufhcture of reticulated glass for which Venice was equally celebrated, was
long lost ; it was at length revived by Pohl, and the crackle glass was in like manner
reproduced by Mr. Apsley Pellattin 1851.
The reticulated glass is produced by a kind of network consisting of small
bubbles of air inclosed within the mass, and ranged in regular series crossing and
interlacmg each other. To produce this ornamental appearance, hollow glass cones
or conical tubes are kept prepared, containing already this network arrangement of
air bubbles. These tubes sre made by arranging a number of small glass rods round
a centre, so as to form a cylinder, and fixing them in this position by melted glass.
The cylinder is then heated until the single rods stick together, when they are drawn
out on the pipe to a long cone, and spirally twisted at the same time, the one half to
the right and the other to the left, when one of these hollow cones is inserted into
the other, and the two are heated until they fuse together ; wherever the littie rods
cross each other a bubble of air will be inclosed, and this occurring in a very regular
GLASS> COLOURED. 863
manner, the rettcolated appearance if produced. The Venetians were alio eele-
brated for their " filigree." This glass has of Uite years been reintroduced in France
and in this country. The process of manufacture has been thus described bj Mr.
Apeley Pellatt, in his CuriositieB of Ghus Manufacture : —
" Before ornaments or Tessels can be bloirn, small filigree canes, with white or
-variously coloured enamels must be drawn. These are first * whetted ' ofi^ to the
required lengths, and then put into a cylindrical mould with suitable internal
recesses, and both cane and mould are thus submitted to a moderate heat The se»
lection of the colonr of the canes depends upon the taste of the manufacturer : two to
four white enamel canes are chiefly used, alternately, with about half the number of
coloured. The blower then prepares a solid ball of transparent flint glass, which being
deposited in contact with the Tarious canes, at a welding heat, occasions them to
adhere. This solid ball is then taken from the mould, is rehoited, and * marvered '
till the adhering projecting ornamental canes are rubbed into one uniform mass ;
the ball is next covered with a gathering of white glass, which must then be drawn
to any size and length that may be required. Should a spiral cane be preferred, the
' pucellas * holds the apex in a fixed position, while the ornamental mass, still adhering
to the glass maker*s iron, is revolyed during the process, till the requisite twist
is given. Where vases are formed of alternately coloured and enamelled filigree
canes, the above process is repeated, and the usual mode of blowing is followed.**
The Venetian haU is a collection of waste pieces of filigree glass conglomerated
together without regular design : this is packed into a pocket o£ transparent glass,
which is adhesively collapsed upon the interior mass by sucking up, producing out-
ward pressure of the atmosphere.
Miu^fhre^ or star work of the Venetians, is similar to the last, only, the lozenges of
glass are more regularly placed.
The Vitro di Trimo of the Venetians is similar to the filigree in many respects ; but
by closing an outer on the inner case, each containing filigree canes, a bubble of air is
inclosed between each crossing of the canes.
The celebrated frosted glass of the Venetians was reintroduced by Mr. Apsley
Pellatt in 1851, who thus describes the process of manuftcture : — ** Frosted glass,
like Vitro di TVtno, is one of the few specimens of Venetian work not previously
made by the Egyptians and the Romans ; and not since executed by the Bohemian
or French glass makers. The process of making it, until recentlv practised at the
Falcon Glass Woiks, was considered a lost art Frosted glass has irregularly varied
marble-like projecting dislocations in its intervening fissures. Suddenly plunging hot
glass into cold water, produces crystalline convex fractures, with a polished exterior,
like Derbyshire spar ; but the concave intervening figures are caused, first by chilling,
and then reheating at the furnace, and simultaneously expanding the reheated ball of
glass by blowing \ thus separating the crystals from each other, and leaving open
figures between, which is done preparatory to forming vases or ornaments. Although
frosted glass appears covered with fractures, it is pei%etly sonorous."
GLASS, COLOURED. Most of the metallic oxides mipart a colour to glass, and
some non-metallic, and even some substances derived from the organie kingdom have
the power of imparting permanent colours to the vitreous combinations of fiint and
potaish. There is much in this subject which still requires examination. M.
Bontemps, at the meeting of the British Association at Birmingham, brought for-
ward some very extraordinary facts in connection with the colouring powers of
different bodies. Of his communication the following is an abstract
In the first place it was shown, that all the colours of the prismatic spectrum might
be given to glass by the use of the oxide of iron in varying proportions, and by the
agency of different degrees of heat : the conclusion of the author being, that all the
colours are produced in their natural disposition in proportion as you increase the
temperature. SimiUr phenomena were observed with the oxide of manganese.
Manganese is employed to give a pink or purple tint to glass, and also to neutralise
the slight green given by iron and carbon to glass in its manu&cture. If the glass
coloured by manganese remains too long in the melting-pot or the annealing-kiln,
the purple tint turns first to a light brownish red, then to yeUow, and afterwards to
^een. White glass, in which a small proportion of manganese has been nsed^ is liable
to become light yellow by exposure to luminous power. This oxide is also, in certain
window glass, disposed to torn pink or purple under the action of the snn*s rays.
M. Bontemps has found that similar changes take place in the annealing oven. He
has determined, by experiments made by him on polygonal lenses for M. Fresnel,
that light is the agent producing the change mentioned : and the author expresses a
doubt whether any change in the oxidation of the metal will explain the photogenic
effect A series of chromatic changes of a similar character were observed with the
oxides of copper, the colours being in like manner regulated by the heat to which
364 GLASS.
the glass was exposed. It was found that silver, although with less intensity, exhihified
the same phenomena ; and gold, although osually employed for the purpose of imparting
varieties of red, was found by varying degrees of heating at a high temperature,
and recasting several times, to give a great many tints, varying from blue to pink,
red, opaque yellow, and green. Charcoal in excess in a mixture of silica-alkkline
glass gives a yellow colour, which is not so bright as the yellow from silver : and
this yellow colour may be turned to a dark red by a second fire. The author is
disposed to refer these chromatic changes to some modifications of the composing
particles rather than to any chemical clumges in the materials employed.
It is not possible in the present essay to enter into the minate details of this beau-
tiful branch of glass manu&cture. In the following statement the materials ordinarily
employed to colour glass alone are named.
YsLiiOW. Charcoal or soot is used for producing the commoner varieties of yellow
glass.
The glass of antimony, which is obtained by roasting sulphide of antimony until
antimonious acid is formed, and melting it with about 5 per cent of undecomposed
sulphide of the same metaL
T7te antimoniate of potash, a preparation similar to James's powder, is stated to
answer the same purpose. Bohemian glass is coloured yellow with glass of antimony,
minium, and oxide of iron.
Silver imparts a very beautifol yellow colour to glass ; but it requires some caution
in its mode of application. It is believed, that the presence of alumina is necessary
to the production of colour, since a fine yellow cannot be produced unless alumina
be present. A mixture of powdered clay and chloride of silver is prepared, and
spread upon the surface of the glass ; the glass is then reheated and the silver pene-
trates to a certain depth into the glass, before the latter softens. The coating is then
scraped off and the fine yellow colour appears. If the silver yellow glass is held
over the flame of burning wood, a peculiar opalescence is produced upon the surface,
probably by the oxidation of the silver.
Uranium produces the beautiful canary yellow, which is found in many articles of
an ornamental kind. This glass possesses the very peculiar property of giving a
green colour when it is looked at, although perfectly and purely yellow when looked
through. This has been attributed to the presence of iron in the conmiercial oxide of
uranium employed ; but the purer the uranium is, the more beautifully will this
phenomenon be brought out It depends upon a very remarkable physical peculiarity
belonging to uranium and some other bodies. See Fluorescence.
Red. a common brownish red colour is produced in glass by oxide of iron, added
as ochre, or in the state of pure peroxide. Muller found ancient red glass to contain dlicie
acid, alkalies, lime, magnesia, alumina, protoxide of iron, and suboxide of copper.
Copper IB more generally employed in colouring glass red. The use of this metal for
this purpose dates from very high antiquitv, and all through the middle ages it was
employed to produce the reds which we see m the fine old windows left by our ancestors
for our admiration. The ancient HcenutHnone was a copper red glass. Suboxide
of copper is used, either in the state of commercial copper scale, or it is prepared by
heating copper turnings to redness. If, during the fusion of the glass in the pot, the
sub -oxide unites with an additional quantity of oxygen, green and not red is the result
This is avoided by combining some reducing agent with the melted substance. Glass
thus coloured does not exhibit its red colour on leaving the crucible ; it is nearly
colourless, or with a tinge of green even when cold ; but if it is then heated a second
time it assumes the red colour. H. Rose supposes that a colourless neutral or acid
silicate of the sub-oxide of copper is formed at a high temperature, and that the subse-
quent so^ning of the glass at a lower temperature causes the decomposition of this
compound and a separation of a portion of the sub-oxide. We believe that no such
chemical change takes place, and that the alteration is due merely to a change in
the molecular arrangement of the particles. The sub -oxide of copper possesses an intense
colouring power, so great indeed that glass coloured with even a very small quantity
is almost impermeable to light; hence it is usual merely to flash colourless glass with
this coloured glass, that is, to spread a very thin film of it ov«r the colourless surface.
A process for colouring glass red after its manufacture with sulphide of copper has
been introduced by Bedford.
Gold can according to circumstances he made to impart a ruby, carmine, or pink
tint to glass. The purple of Cassius, was employed ; but Dr. Fuss fibrst showed that
a mere solution of gold without the presence of tin, as in the salt named, is capable
of producing rose and carmine coloured glass.
Similar changes to those already described with copper occur with the salts of
gold. Perhaps the glass is colourless in the pot, and it then remains colourless when
cold ; but when reheated, the glass quickly assumes a light red cplour, which rapidly
GLASS. 365
gpreads flrom tbe beftted point orer the whole glass, and inereaBes in intensity nntil it
becomes nearly a black red. This coloured glass can be again rendered coloarless
by fusion and slow cooling ; its colour is again produced by a repetition of the heating
process. I^ however, it is suddenly cooled it cannot again be made to resume its
ruby colour. This is also an example confirmatory in the highest degree of the
yiew, that no chemical change takes place } but that all the phenomena are due to
alterations in molecular structure. The practice of flashing colourless glass with the
ruby ghiss from gold is commonly adopted. The beautiful examples of the Bohe-
mian glass manufacture, in which we have a mixture of rich ruby and the purest
crystal, are produced in this way. A globe of hot colourless glass is taken firom the
pot, and a cake of ruby glass prepared with a composition called tchmebze^ is warmed
and brought into contact with the melted globe $ this ruby glass rapidly diffuses
itself over the surface, and the required article is blown or moulded with a coating
of glass, coloured ruby by gold, of any required thickness.
Schaiebze is prepared with 500 parts of silica, 800 of minium, 100 of nitre, and the
same quantity of potash, A very small portion of a solution of gold in aqua regia is
intimately mixed with 500 parts of schmebze, 43 parts of prismatic borax, 8 or 4 of
oxide of tin, and a similar quantity of oxide of antimony. This mixture is heated for
twelve hours in an open crucible placed in a flat furnace, and then cooled slowly in an
annealing oven. A Bohemian ntby, especially so called, is prepared by melting to-
gether fidminating gold rubbed in with oil of turpentine, quartz powdered, and fhtted
minium, sulphide of antimony^ peroxide of manganese, and potash. Bohme has given
an analysis of a Venetian ruby glass, in which j^ of a grain of gold is combined with
about 150 of the ordinary ingredients of glass, with some tin and iron.
Manaanese is sometimes employed to give a fine amethystine colour to glass ;
care is however required to prevent the reduction of the peroxide of manganese m the
process.
Green. Green colours may be obtained by a variety of metallic oxides. Protoxide
of iron imparts a dull green ; an emerald green colour is given by oxide of copper.
Either copper scales or verdigris dried and powdered are employed, the colour beinff
much finer with a lead glass, than with one containing no lead. Translucent or dwi
^lase is converted into a deep blue or turquoise colour by oxide of copper and not
into a green. An emerald green is also produced by the oxide of chromium. Two kinds
of Bohemian green glass, known respectively as the ancient and modem emerald
greens, are prepared from mixtures of the oxides of nickel and of uranium.
Blue. The only fine blue is produced by cobalt The manufacture of smalt or
zqffre is so important that it will bo treated of in a separate article. See Smalt and
Cobalt.
Brown. Peroxide of manganese with zaffre yields a fine garnet-like brown.
Pink or Flesh Colour. Oxide of iron and alumina, obtained by heating a mixture
of alum and green vitriol.
Orange. Peroxide of iron with chloride of silver.
Jasper. A Bohemian glass, generally black, but of fine lustre, prepared by adding
forge scales, charcoal, and bone ashes to the ordinary materials for glass.
Amongst the different varieties of glass, artificial gems may be enumerated. For a
description of their manufacture, see Gems, Artificial.
GLASS^ ttr phytical conditions and chemical constitution, — So fiur as may be in-
ferred, from the analysis of ordinary commercial samples of window-glass, this substance
has not only a very variable composition, but, worse than this, it is out of all keeping
with anything like definite proportion. That it should be full of striss, and, therefore,
refract the rays of light unequally, as it does, so as to produce the most hideous ap-
pearances of distortion, is a mere natural consequence of its mechanical composition,
which might, and must one day be corrected ; but that whole nations shoidd have
come to view this defect as an unavoidable peculiarity, is precisely one of those sur-
prising facta which demonstrate the influence of habit over the powers of the mind,
and show how easily human reason can reconcile itself to the most gross inconsist-
encies. If window-glass had one uniform atomic composition, the tendency to form
these stria would nowhere exist in excess ; and, therefore, their production would
diminish as the skill of the workmen increased ; but, with the present variable com-
pound, the glass stretches unequally in different parts, by an equal application of
force, and, in spite of human skill, presents a result alternately thick or thin, as ac-
cident determines. That these striae have not the same composition as the parts sur-
rounding them is very obvious, fh>m the circumstance that, if striated glass be cut to
an uniform thickness, and polished on both sides, the optical defects remain but little
changed, and occasionally they are found to be increased. Again it is known, that
the more complex the composition of any glass may be, the greater the liability to this
striated stractfure, — of wluch flint glass offers an apposite illustration ; for here, in
366 GLASS.
addition to the ordinary components of glass, the silicate of lead is superadded. Now-
the specific gravity of silicate of lead is very high compared with that of nlieate of
soda, potash, or lime ; hence, unless employed in the exact quantity to form a
chemical combination with the other silicates, a mere mechanical mixture is produced
of very different densities throughout ; and the product, under the action of ligfat, dis-
plays, permanently, that peculiar ftigitiye appearance seen when syrup and water, or
alcohol and water, are mixed together ; that is to say, a series of curved lines are
formed by the unequal refraction of the two fluids, which entirely disappear, so soon
as perfect admixture has taken place, but which remain in the case of flint-glass,
from the utter impossibility of effecting the necessary union between its various parts.
Although, however, this cannot be done mechanically, yet, in a chemical way, nature
performs such operations with ease and unerring fidelity. The French chemist,
Berthier, long ago proved that many neutral salts combine together by fusion in
atomic proportions, and form new and definite compounds. Thus, carbonate of potash
and carbonate of soda when mixed, atom for atom, unite and produce a compound
more easy of fhsion than the most fusible of the two: — similarly, either of these car*
bonates will act with carbonate of baryta or strontia, and again, fluor-spar and
sulphate of lime, two remarkably infusible substances, when mixed, melt readily, at
a low red heat into a fluid as mobile and transparent as water. It is useless to mul-
tiply examples of this kind, for thousands exist; and the idkaline and earthy silicates
form no exception to this aJmost universal rule. A mixture of silicate of potash and
silicate of soda will, if in atomic ratios, fuse much more readily than either of them
alone. But now, let us imagine an attempt to fuse these two bodies together, in any
other proportion than that in which they are naturally disposed to combine ; — say
that the silicate of soda is in excess } then the silicate of potash would unite with
exactly sufficient of the silicate of soda to produce the extremely fusible compound
above spoken of ; whilst the less easily fiisible silicate of soda, added in excess, would
form a kind of network throughout the mass. It may be said, that a higher heat
would overcome this difficulty, by thoroughly liquefying the silicate of soda *, and this
is really the plan now used with that view ; but, independent of the fact that the
mixed silicate of potash and soda would also undergo a corresponding liquefaction,
and, therefore, favour the separation of the silicate of soda ; yet, as chemical union is
impossible, from the yery conditions of the experiment, even the roost perfect me-
chanical mixture, under the greatest advantages of fluidity, would never generate a
homogeneous body. The strias might, indeed, be diminished in sise ; but this would
impl^ a corresponding increase in their number ; and, if carried very far, complete
opacity would result fh>m such an endeavour to subvert the laws of nature. The
power of the workmen to remedy this defect is therefore limited to the capability of
modifying its more salient features ; he can neither remove nor destroy it What
we have here illustrated by the simplest of all assumptions, gathers and accumulates
into a formidable evil when several silicates are fused together, having considerable
differences of specific weight Thus, in the case of flint-guiss before alluded to, there
are generally three, and sometimes five, of these silicates fused together, into, pro-
bably, one of the most antagonistic compounds that could be conceived, refracting and
dispersing the ray of light in fifty directions, and demonstrating the unfriendly
nature of its coerced union, by flying in pieces fi'om the most trivial applications of
heat or violence. Yet in flint-glass we are not surpassed, nor indeed equalled, by
any other nation ; and so thoroughly has this beautiful substance become associated
with our industrial reputation, that the British name, flint-glass, has been adopted into
several continental languages. Nevertheless, it cannot be doubted that a wide field of
improvement is open in this quarter, and that some more solid foundation is needed by
our manufacturers in this line, than the prestige of a name, or the fbrce of capital.
In France, as in England, the ingredients are mixed with some care, and intro-
duced into a crucible, heated by a powerful furnace. These ingredients are sand or
silica, carbonate of soda, and carbonate of lime, with perhaps a little ground felspar in
some cases. The carbonate of soda is first attacked by the silica, and its carbonic acid
driven o£^ whilst the remaining silica and carbonate of lime become imbedded in the
vitrifying mass.^ As the heat mcreases, a more perfect fusion takes place ; and then
the carbonic acid of the carbonate of lime makes its way through the fused materials
by which they are mechanically mingled together during the effervescence, which is
technically tenned the " boil ; " and, provided no after separation ensues from the
process of " settling," the whole crucible or "pot" of glass will have a uniform com-
position. But, as we have seen, this depends altogether upon the relative proportion
of the materials towards each other, for an excess of either one or other of the bases
will destroy the homogeneous character of the whole, and introduce a plexus of stris.
Now the plate-glass of St Gobain is almost exactly an atomic compound, and consists
of one atom of the trisilicate of soda and one atom of the trisilicate of lime, with a
GLASS. 867
ill percentage of alnmina. The onion is thereftwe complete ; and wlien it is re-
membered that the celebrated French ohemiat, Gar-Lnnac, vas regularly employed
as an adviser to this company* and that his son, M. Jules Lossac, retains that ap-
pointment to this day, it is not very snrprising that oar mannfactnrers are defeated in
the article of plate-glass. Science most ever take the lead of prejudice and custom.
The examination of English plate-glass folly corroborates the seneral result deduced
horn the action of light. There is no Approach to an atomic arrangement The
principal constituent is trisilicate of soda, but yariable qusntities of lime, alumina,
and even magnesia, exist in it. Potash is sometimes present, and oxide of iron is
uiTariably so ; but in not one single instance, out of 17 samples examined with great
care, could so much as a surmise of the doctrine of combining proportions be gathered
from the result of the analyseSb Similarly fruitless was a research instituted upon flint*
glass, both British and foreign. Of 35 samples analysed, no satisfactory evidence
could be adduced to favour the opinion that science had been a helpmate to industry,
or was at all concerned in this branch of manufacture. There are, however, some
points of vast interest associated with the practical working out of this matter. Potash
IS known to give a more brilliant and haMer glass than soda, and alumina seems to
tend in the same direction. The Bohemian glass, so celebrated throughout Europe, is
a glass of this description, and contains silicate of alumina, silicate of lime, and silicate
of potash, but not in chemical proportions. This glass is therefore striated, but it
seems to permit of a more perfect decoration by metallic oxides than can be de-
veloped m glass of lime and soda. This very probably depends upon the alumina
contained in it From some singular oversight, the use of carbonate of baryta has not
yet found its way into the composition of glass, though we can scarcely conceive a
more hopeftil materiaL This substance may be had in large quantity in the Korth of
England, of great purity, and at a merely nondnal cost as compared with its value
for such a purpose as glass-making. Ihat it wonld fose readily with a due amount
of soda, and give ** a boil** as well as chalk, there can be no doubt ; whilst its great
density will certainly improve the refttustive power of the resulting product, and thus
rival the brilliancy of lead or flint-glass, without imparting that sofbiess and liability
to receive scratches which are so objectionable in the latter variety. One difliculty
may perhaps reside in the want of information concerning the quantity to be em-
ployed. But this is easily a4j listed ; for it has been demonstrated that, during vitri-
fication, the silicic acid unites to bases in the proportion of three atoms to one :
consequently three atoms, or 1S8 parts, will always require one atom of each base.
TheredTore, this weight of good dry sand may be set against 64 of dry carbonate of
soda, 70 of carbonate of potash, 50 of pure marble or c^k, 99 of carbonate of baryta,
and 112 of oxide of lead or litharge. Suppose, then^ that the object is to employ
carbonate of baryta for the first time, here 6 atoms or 276 parts of sand, 1 atom or 64
parts of dry carbonate of soda, and 1 atom or 99 parts of carbonate of baryta, may be
mixed and fused together with every prospect of obtaining a good result ; or 9 atoms
of silica, 1 of carbonate of potash, 1 of carbonate of soda, and 1 of carbonate of baryta,
might be tried without fear of failure. Again, in the case of flint-glass, 112 of
litharge, 54 of soda, and 276 of sand, would probably succeed, or an additional atom
of trisilicate of potash might be used. For many years past, M. Dumas, now, perhaps,
the first chemist in France, has been in the habit at demonstrating to his pupils that
glass of all kinds, when properly made, must necessarily be an atomic compound }
and yet we scarcely expect to find a single British glasonaker who will admit that
his art is susceptible of such decisive and beautiful simplification.
To assist as fiur as we can in the attainment of this end, we shall proceed to describe
a simple means for the analysis of glass, which will enable any person, possessed of
even very trifling chemical skill, to determine the composition of any given sample of
glass in a comparatively short time. From the nature of the material, it becomes ne-
cessary to divide the analysis into two distinct portions ; one of which has for its
object the estimation of its alkaline ingredients, the other that of the earthy, metallic,
and siliceous matters. Having heated a sufficient quantity of the sample in question
to dull redness, it must be suddenly thrown, whilst still hot, into a basin containing
cold water. In this way it becomes cracked and flawed in all directions, so as to
favour its redaction into powder. When dry it must, tiierefore, be carefully ^und
In an agate or steel mortar, until it has the appearance of flue flour. Nor is it a
matter of indifference whether this takes place in contact with water or not ; for glass
in this extreme state of comminution, readily gives up a part of its alkali to water ;
and hence, if ground in the presence of that fluid, the resulting analysis would prove
incorrect. But we will suppose that a quantity of finely powdered glass has been ob-
tained as above indicated, and the amount of its alkali is desired ; then weigh out
100 grains of the glass, and carefaliy mix with it 200 grains of pure fluor spar in a
similarly powdered condition. Place the mixture in a platinum or leaden vessel, and
368 GLASS.
poor over it 500 gnuns of strong salphuric acid, — stirring the whole well togedier
with a silyer spoon, but taking care not to remoye any portion of the materials.
Next, apply a heat of ahoat 212^ Fahr. ; and as the process draws to a conclusion,
this may be raised as high as 300^. When all evolution of gaseous fumes has ceased,
water may be poured on the residuary mass to the extent of four or five ounces, and
the mixture thrown on a filter. After the clear fluid has passed through, a little more
water must be added to the filter, so as to -^ash out the whole of the soluble matter ;
these washings being joined to the original clear fluid, which consists of sulphate of
soda or potash, or both, with a quantity of sulphate of lime, and perhaps also of
magnesia and alumina. To this an excess of carbonate of anmionia must now be
added, to admit of the separation of the earthy salts being effected by filtration. The
clear solution is next boiled down to dryness, and the residue is heated red-hot for a
minute or two. This residue is the soda or potash, or both, formerly contained in
100 ffrains of the glass, but now united to sulphuric acid. Having ascertained its
weight, the relative proportions of potash and soda may be found by testing its con-
tent of sulphuric acid with a barytic solution, and calculating the result by the well-
known Archimedean equation ; or by dissolving the mixed salt in a small quantity of
water, and, after adding an excess of tartaric acid, leaving the whole for a few hours
covered up in a cool place. Almost the whole of the potash will separate in this way
as bitartrate of potash. The quantity of alkali may be determined from the atomic
constitution of Uie alkaline salts. Thus, supposing the dry residue altogether com-
posed of sulphate of soda, then as 72 grains of it indicate 32 of pure soda, the result
may be obtained by the rule of proportion. The amount of alkali being known,
another portion of the powdered ^lass must be employed for ascertaining the re-
mainder of the ingredients. That is to say, 100 grains of the sample must be mixed
with 200 grains of pure potash, and the whole fused together in a silver crucible, at a
red heat, until perfect liquefaction ensues, when the crucible and its contents may be
withdrawn from the fire, and, as soon as cool enough, boiled in half a pint of pure
water, so as thoroughly to dissolve the fused mass from the crucible. An excess of
nitric acid being poured into the solution, the mixture is then evaporated to dryness,
by which means the silicic acid is rendered insoluble ; consequently, on the applica-
tion of water, this remains, and may be dried and weighed, whilst the lime, alumina,
and lead of the glass may be separated from the soluble portion by the addition, first,
of sulphuretted hydrogen, which separates the lead, then of ammonia, which throws
down the alumina, and, next, by pouring in carbonate of ammonia, which precipi-
tates the lime as a carbonate. Thus, therefore, the alkaline matters are found by one
process, and the silica, earthy, and metallic constituents by another, both of which may-
be conducted at the same time. It has been recommended to employ carbonate of
baryta in the analysis of glass ; but the high temperature required with this sub-
stance dissipates a portion of the alkaline components, and thus leads to serious errors.
Even mere fusion in a glass furnace expels soda from glass, and renders it more and
more infusible ; but this expulsion is much favoured by the presence of baryta. The
above method of analysing glass is, therefore to be preferred to the baryta plan, by
individuals not habitually engaged in manipulative chemistry.— C/re.
GLASS /or horticultural pitrpwea, — An impression taken up loosely in the first in-
stance from some experiments on the action of the chemical rays of light, when
made to permeate coloured glass, has led the public frequently to conceive that
glasses which admitted freely the chemical rays were the most adapted to accelerate
the growth of plants. No more mistaken view was ever entertained. At different
periods in the life of a plant different influences are necessary ; at one time Uie
chemical force is required, at another the luminous power, and at another the calorific
agent The solar rays, as we receive them direct from the sun, have those forces
exactly adjusted to produce the best possible conditions; but under some of the artificial
conditions in which we place plants, it is important to know the conditions of the solar
rays best suited to produce a given effect This we must briefly attempt to explain : —
1. Seeds germinating absorb oxygen, and convert their starch into sugar ; this is a
purely chemical process, and demands the fuU power of the chemical rayt (actinism).
2. Wood forming, from the decomposition of carbonic acid, is a function of the
vital power of the plant, excited by light (luminous force).
3. Flowering and fruiting manifest compound actions, and appear to demand the
combined power of heat (caXorific power) and of the chemical rays.
Such are the three chief conditions in the phenomena of vegetable growth. Now
a, a glass stained blue with cobalt admits the permeation of the chemical rajrs with
great freedom, obstructing both light and heat ; 6, a glass stained yellow with silver,
will powerfully obstruct the chemical rays, and allow the luminous rays to pass freely ;
c, deep copper or gold red glasses admit the maximum heat rays to pass freely, and
in general allow of the permeation of a small quantity of the chemical rays.
GLASS CUTTING AND GRINDING.
369
906
When Med is placed in the soil to germinate, a blae glass placed aboTe the soil will
greatly accelerate the process, the first leases will appear above the soil, in many in^
stances, days before they are seen when the seed is under the ordinary conditions in
the soil ; but if a plant is allowed to grow under these circumstances, scarcely any
wood is produced, but long succulent stalks are formed, with imperfect leaves.
After germination has taken place, if the plant is brought under the influence of
the rays permeating yellow glass {light separated to a considerable extent from the
chemical power), wood is formed abundantly, and very healthy plants with dark
leaves are produced. For the production of perfect flowers and fruit, the red glass
named is the most effective. Plants growing in conservatories which have been
glazed with the colourless German sheet glass, frequently suffer from scorching. To
avoid this if possible, the editor of this volume was consulted on the glass which
should be employed in glazing the great palm house at Kew, the problem being to
avoid the necessity of blmds, and to secure the plants from the injurious action of the
scorching rays. By a long series of experiments it was determined that glass
stained green with a little of the oxide of copper, and from which there was an entire
absence of the oxide of manganese, entirely effected this end. The great palm house
in the Royal Botanic Gardens at Kew was glazed with glass made on this principle,
by the Messrs. Chance Brothers and Co. of Birmingham, and it has now been tested
by the sunshine of twelve summers (1859) ; and the plants, as every one may ob-
serve, grow most luxuriantly, and are entirely free from any indications of scorching
on their leaves.
GLASS CUTTING AND GRINDING, for common and optical purposes. By
this mechanical process the surface of glass may be modified into almost any orna-
mental or useful form.
1. 7*Ae grinding of crystal ware. This kind of glass is best adapted to receive
polished facets, both on account of its relative softness, and its higher refractive power,
which gives lustre to its surface. The cutting shop should be a spacious long apart^
ment, furnished with numerous skylights, having the grinding and polishing lathes
arranged right under them, which are set in motion by a steam-engine or water-wheel
at one end of the building. A shaft is fixed as
usual in gallowses along the ceiling; and from
the pulleys of the shaft, bands descend to turn the
different lathes, by passing round the driving
pulleys near their ends.
The turning lathe is of the simplest construc-
tion. Fig. 906, Dk is an iron spindle with two well-
turned prolongations, running in the iron puppets
a a, between two concave boshes of tin or type
metal, which may be pressed more or less to-
gether by the thumb-serews shown in the figare.
These two puppets are made fast to the wooden
support B, which is attached by a strong screw and
bolt to the longitudinal beam of the workshop a.
s is the fhst and loose pulley for putting the lathe
into and out of geer with the driving shaft. "ITic projecting end of the spindle is
ibmished with a hollow head-piece, into which the rod c is pushed tight. This rod
carries the cutting or grinding disc plate. For heavy work, this rod is fixed into
the head by a screw. When a conical fit is preferred, the cone is covered with lead to
increase the friction.
Upon projecting rods or spindles of that kind the different discs for cutting the glass
are made fast Some of these are made of fine sandstone or polishing slate, from 8 to
10 inches in diameter, and from } to j inch- thick. They must be carefully turned and
polished at the lathe, not only upon their rounded but upon their flat face, in order to
grind and polish in their turn the flat and curved surfaces of glass vessels. Other discs
of the same diameter, but only J of an inch thick, are made of cast tin truly turned,
and serve for polishing the vessels previously ground ; a third set consists of sheet
iron frona } to | an inch thick, and 12 inches in diameter, and are destined to cut
grooves in g:lass by the aid of sand and water. Small discs of well-hammered copper
from. ^ to 3 inches in diameter, whose circumference is sometimes flat, and sometimes
concave op convex, serve to make all sorts of delineations upon glass by means of
emery and oil Lastly, there are rods of copper or brass furnished with small hemi-
spheres from ji to j^ of an inch in diameter, to excavate round hollows in glass.
Wooden discs are also employed for polishing, made of white wood cut across the
grain, as also of cork.
The cutting of deep indentations, and of grooves, is usually performed by the iron
Vol*. II. B B
370 GLA.SS CUTTING AND GRINDING.
disc, with sand and water, which are allowed constantly to trickle down from a wooden
hopper placed right over it, and famished with a wooden stopple or plug at the apex,
to regulate by its greater or less looseness the flow of the grinding materials. The
same effect may be produced by using buckets as shown in fig, 907.
907 The sand which is contained in the bucket f, above the lathe, has a
spigot and faucet inserted near its bottom, and Is supplied with a
stream of water from the stopcock in the vessel o, which, together,
running down the inclined board, are conducted to the periphery of
the disc as shown in the figure, to whose lowest point the glass
Tressel is applied with pressure by the hand. The eand uid water
are afterwaids collected in the tub h. Finer markings which are to
remain without lustre, are made with iiotR small copper discs, emery,
and oiL The polishing is effected by the edge of the tin disc, whidi
is from time to time moistened with putty (white oxide of tin) and
water. The wooden disc is also employed for this purpose with
putty, colcothar, or washed tripoli. For fine delineations, the glass
is first traced over with some coloured varnish, to guide the hand of
the cutter.
In grinding and facetting crystal glass, the deep grooves are first
cut, for example, the cross lines, with the iron disc and rounded edge,
by means of sand and water. That disc is one sixth of an inch thick
and 12 inches in diameter. With another iron disc about half an
inch thick, and more or less in diameter, according to the cnrvatare
of the surface, the grooves may be widened. These roughly cut parts mutt be next
smoothed down with the sandstone disc and water, and then polished with the wooden
disc about half an inch thick, to whose edge the workman applies, from time to time,
a bag of fine linen containing some ground pumice moistened with water. When the
cork or wooden disc edged with hat felt is used for polishing, putty or colcothar is ap-
plied to it. The above several processes in a large manufactory, are usually com-
mitted to several workmen on the principle of tbe division of labour, so that each may
become expert in his department
2. Th& grinding of optical glasses The glasses intended for optical purposes being
spherically ground, are called lenses ; and are used either as simple magnifiers and
spectacles, or for telescopes and microscopes. The curvature is always a portion of a
sphere, and either convex or concave. This form insures the convergence or diver-
gence of the rays of light that pass through them, as the polishing does the brightness
of the image.
The grinding of the lenses is performed in brass moulds, either concave or convex,
formed to the same curvature as that desired in the lenses ; and may be worked either
by hand or by machinery. A gauge is first cut out of brass or copper plate to suit
the curvature of tbe lens, the circular arc being traced by a pair of compasses. In
this way both a convex and concave circular gauge are obtained. To these gauges
the brass moulds are turned. Sometimes, also, lead moulds are used. After the two
moulds are made, thev are ground face to face with fine emery.
The piece of glass is now roughed into a circular form by a pair of pincers, leaving
it a little larger dian the finished lens ought to be, and then smoothed round upon the
stone disc, or in an old mould with emery and water, and is next made ftst to a hold-
fast. This consists of a round brass plate having a screw in its back ; and is some*
what smaller in diameter than the lens, and two thirds as thick. This is turned
concave upon the lathe, and then attached to the piece of glass by drops of pitch ap-
plied to severe points of its surface, taking care, while the pitch is warm, that the
centre of the glass coincides with the centre of the brass plate. This serves not merely
as a holdfast, by enabling a person to seize its edge with the fingers, but it prevents
the glass from bending by the necessary pressure in grinding.
The glass must now be ground with coarse emery upon its appropriate mould,
whether convex or concave, the emery being all the time kept moist with water. To
prevent the heat of the hand from affecting the glass, a rod for holding the brats
plate is screwed to its back. For every six turns of circular motion, it must receive
two or three rubs across the diameter in different directions, and so on alternately.
The middle point of the glass must never pass beyond the edge of the mould ; nor
should strong pressure be at any time applied. Whenever the glass hat assumed the
shape of the mould, and touches it in every point, the coarse emery must be washed
away, finer be substituted in its place, and the grinding be continued as before, tiU all
the scratches disaj^ar, and a uniform dead surface be produced. A commencement
of polishing is now to be given with pumice-stone powder. During all this time the
convex mould should be occasionally worked in the concave, in order that both may
preserve their correspondence of shape between them. After the one sorfitce luit
GLOVE MANUFACTURE. 371
been thus finished, the glass must be turned oyer, and treated in the same way upon
the other side.
Both surfaces are now to be polished. With this view equal parts of pitch and resin
must be melted together, and strained through a cloth to separate all impurities. The
concave mould is next to be heated, and covered with that mixture in a fluid state to
the thickness uniformly of one quarter of an inch. The cold convex mould is now to
be pressed down into the yielding pitch, its surface being quite clean and dry, in order
to give the pitch the exact form of the ground lens ; and both are to be plunged into
cold water till they be chilled. This pitch impression is now the mould upon which
the glass is to be polished, according to the methods above described, with finely
washed colcothar and water, till the surface become perfectly clear and brilliant. To
prevent the pitch from changing its figure by the friction, cross lines must be cut in it
about ^ an inch asunder, and l-12th of an inch broad and deep. These grooves re-
move all the superfluous pans of the polishing powder, and tend to preserve the
polishing surface of the pitch clean and unaltered. No additional colcothar after the
first is required in this part of the process, but only a drop of water from time to
time. The pitch gets warm as the polishing advances, and renders the friction more
laborious from the adhesion between the surfaces. No interruption must now be
suffered in the work, nor must either water or colcothar be added ; but should the
pitch become too adhesive, it must be merely breathed upon, till the polish be com-
plete. The nearer the lens is brought to a true and fine surface in the first grinding,
the better and more easy does the polishing become. It should never be submitted to
this process with any scratches perceptible in it, even when examined by a magnifier.
As to small lenses and spectacle eyes, several are ground and polished together.
The pieces of glass are affixed by means of a resinous cement to the mould, close to
each other, and are then all treated as if they formed but one large lens. Plane
glasses are ground upon a surface of pitch rendered plane by the pressure of a piece
of plate glass upon it in its softened state.
Lenses are also ground and polished by means of machinery, into the details of which
the limits of this work will not allow us to enter. See Lenses.
GLASS PAPER and CLOTH. Paper or cloth being covered with glue, sand,
varying in its degree of fineness, is dusted over it, and of course adheres. These are
used for polishing, or removing the roueh surfaces of woods or metals.
GLAUBER'S SALTS (the Sai camarticus Giauberi, or Std mirabiU Ghtuberi).
Sulphate of soda was discovered by Glauber in 1658. Its composition is : —
Soda 19*24
Sulphuric acid ----- 24-76
Water 56*00
100*00
GLAZES. See Pottery.
GLAZIER, is the worknuin who cuts plates or panes of glass with the diamond,
and fastens them by means of putty in frames or window casements. See Diajionp,
for an explanation of its glass-cutting property.
GLAZING. The process of giving a hard polished surface to bodies. Paper is
glazed by the use of resins, gelatine, &c See Paper. Pottery is glazed by the use
of certain fusible materials. See Pottery and Porcelain. Some metals are said
to be " glazed *' when, by means of polishing wheels, the highest finish is put upon
their surfaces.
GLOVE MANUFACTURE. In February, 1822, Mr. James Winter of Stoke-
under -Hambdon, in the county of Somerset, obtained a patent for an improvement
upon a former patent nuichine of his for sewing and pointing leather gloves. Fig. 908,
represents a pedestal, upon which the instrument called the jaws is to be placed.
Fig, 909 shows the jaws, which instead of opening and closing by a circular move-
ment upon a joint, as described in the former specification, are now made to open
and shut by a parallel horizontal movement, effected by a slide and screw ; a a is
the fixed jaw, made of one piece, on the under side of which is a tenon, to be inserted
into the top of the pedestal. By means of this tenon the jaws may be readily
removed, and another similar pair of jaws placed in their stead, which affords the
advantage of expediting the operation by enabling one person to prepare the work
whilst another is sewing ; 6 6 is the movable jaw, made of one piece. The two jaws
being placed together in the manner shown at fig. 910, the movable jaw traverses back-
wards and forwards upon two guide-bars, c, which are made to pass through holes
exactly fitted to them, in the lower parts of the jaws. At the upper parts of the jaws
are wnat are called the indexes, d d, which are pressed tightly together by a spring
shown fit fig. 911, and intended to be introduced between the perpendicular ribs of
the jaws at e. At / is a thumb-screw, passing through the ribs for the purpose of
BB 2
372
GLOVE SEWING.
909
913
paQnaQQQBaBQBtinBHBI
914
912
910
tiffhtening the jaw8, and holding the leather fest between the indexes while hemg
sewn : this screw, however, will seldom, if ever, be necessary if the spnng is suffi-
ciently strong ; ^ is an eye or nng fixed to
the movable jaw, through which ^e end of
a lever, A in fig. 908, pusses ; this lever is
connected by a spring to a treadle t, at the
base of the pedestal, and by the pressure of
the right foot upon this treadle, the movable
jaw is withdrawn; so that the person em-
ployed in sewing may shift the leather, and
place another part of the ^love between the
jaws. The pieces called indexes are con-
nected to the upper part of the jaws, by
screws passing4hroagh elongated holes which
render them capable of adjustment
The patentee states, that in addition to the
index described in his former patent, which
is applicable to what is called round-seam
sewing only, and which permits the leather
to expand but in one direction, when the
needle is passed through it, namely, upwards,
he now makes two indexes of different con-
struction, one of which he calls the receding
index, and the other the longitudinally
grooved index. Fig. 911 represents an end
view, and fig. 9 12, a top view of the receding
index, which is particularly adapted for what
are called ** drawn sewing, and prick-seam
sewing." This index, instead of biting to
the top, is 60 rounded off in the inside from
the bottom of the cross grooves, as to permit
the needles, by being passed backwards and
forwards, to carry the silk thread on each side of the leather without passing over
it Fig. 913 represents an end view of the lon^tudinally grooved index, partly
open, to show the section of the grooves more distmctly; andjf^. 914 represents an
inside view of one side of the same index, in which the longitudinal groove is shown,
passing from k to I This index is more particularly adapted to round-seam sewing,
and permits the leather to expand in every direction when the needle is passed through
it, by which the leather is less strained, and the sewing consequently rendered much
stronger.
GLOVE SEWING. The following simple and ingenious apparatus, invented by
an Englishman, has been employed extensively in Paris. The instrument is shown
in profile ready for action in
fig. 915. It resembles an iron
vice, having the upper portion
of each jaw made of brass, and
tipped with a kind of comb of
the same metaL The teeth of
this comb, only one-twelfth of
an inch long, are perfectly re-
gular and equal. Change combs
are provided for different styles
of work. The vice a. a is made
fast to the edge of the bench or
table B, of the proper height,
by a thumb-screw c, armed with
a cramp which lays hold of the
wood. Of the two jaws com-
posing the machine, the one p
is made fast to the foot ▲ a,
but the other b is movable
upon the solid base of the machine, by means of a hinge at the point f. At 1 1 is
shown how the upper brass portion is adjusted to the lower part made of iron ; the
two being secured to each other by two stout screws. The comb, seen separately m
fig. 917, is made fast to the upper end of each jaw, by the three screws n,R,ti. Ftg.
916, is a front view of the jaw mounted with its comb, to illustrate its construction.
The lever k corresponds by the stout iron wire i^ with a pedal pressed by the
.>AA*lAAU^tA*AAm**U*UMi
916
917
fmtwmitwmmmimfmfm^
S
^
GLUCEsrUM. 373
needle-woman's foot, whenever she wishes to separate the two jaws, in order to insert
between them the parallel edges of leather to be sewed. The instant she lifts her
foot, the two jaws join by the force of the spring o, which pushes the moyable jaw
B against the stationary one D. The spring is made fast to die fhime of the yice by
the screw h.
After patting the doable edge to be sewed in its place, the woman passes her needle
successively through all the teeth of the comb, and is sore of making a regular seam
in erery direction, provided she is careful to make the needle graze along the bottom
of the notches. As soon as this piece is sewed, she presses down the pedal with her
toes, whereby the jaws start asunder, allowing her to introduce a new seam; and so
in quick succession.
The cumb may have any desired shape, straight or curved ; and the teeth may be
larger or smaller, according to the kind of work to be done. With this view, the
combs might be changed as occasion requires ; but it is more economical to have sets
of vices ready mounted with combs of every requisite size and fornn.
GLUCINA {Glueine, Fr. ; BeryUerde, Qerm.) is one of the primitive earths, ori-
ginally discovered by Yauqaelin in 1797 in the emerald of Limoges; he called it
glucina from the sweet taste possessed by its salts. Its existence in several other
minerals has since been proved: viz., in cymophane or chrysoberyl, phenacite,
enclase, gadolinite, leucophane, &c. Its properties have been comparatively little
studied, owing to the tedious and expensive processes required for its preparation.
From the circumstance that this earth may probably be employed in the production of
gems by artificial methods, it is thought important to describe its peculiarities fully.
GLUCINUM, the metal of Glucina has been obtained by 11. H. Debray (AnTt.
Chym. et Phys. xliv. 5), by the following process. Into a wide glass tube are intro-
duced two vessels, one containing chloride of glucinun^ and the other sodium,
deprived of the greatest part of the adhering naphtha by compression between two
sheets of blotting paper. The glass tube is placed in a combustion Aimace. It is
then traversed by a current of hydrogen, passing from the chloride of glucinum to
the sodium. The sodium is not placed in the tube until all the air has been expelled
by the hydrogen. The tube is then heated just where the sodium is placed, which
by this means is deprived of the last particles of naphtha, and fuses. The chloride of
glucinum is then heated. The vapour of chloride driven forwards by the hydrogen
arrives over the fused sodium. It then swells up, and the heat generated by chemical
action is sufficient to raise the contents of the vessel to redness, which often breaks the
vessel if made of porcelain. The operation is ended when the chloride of glucinum
sablimes beyond the sodium vesseL When the tube is cool the vessel is withdravm, and
in the place of the sodium a large quantity of a blackish substance is found, composed
of common salt and the metal glucinum in brilliaift spangles, and sometimes even in
globules. This mass is quickly detached and fased in a small crucible, with the addi-
tion of some dried conunon salt, which acts as a flux, and facilitates the union of the
globules of metaL
It is a white metal, whose density is 2-1. It may be forged and rolled into sheets
like gold. Its melting point is inferior to that of silver. It may be melted in the
outer blowpipe flame, without exhibiting the phenomenon of ignition presented by
zinc and iron under the same circumstances. It cannot be set on fire in an atmo-
sphere of pure oxygen, but in both cases is covered with a film of oxide, which seems
to protect it from further action. It is not acted on by sulphur, but readily combines
with chlorine and iodine by the aid of heat
Silicium unites readily with it, forming a hard, brittle substance, capable of taking
a high polish. This substance is always formed when glucinum is prepared in porce-
lain vessels, the silica being reduced by this metaL After several fusions in such
vessels, glucinum may contain as much as 20 per cent of silicium. Glucinum does
not decompose water at the temperature of ebullition, nor even at a white heat
Sulphuric and hydrochloric acids dissolve it easily, either concentrated or diluted,
with the evolution of hydrogen.
Nitric acid, even when concentrated, has, at ordinary temperatures, no action upon
it, and dissolves it bat slowly when boiling.
Glucinum, though not acted on by ammonia, dissolves readily in caustic potash.
The metal which Wohler obtained, by igniting chloride of glucinum with potassium
in a platinum crucible, differs considerably fh>m that just described \ the metal thus
obtained being a grey powder, very refractory in the furnace, bat combines with
oxygen, chlorine, and sulphur much more energetically than the metal desdribed by
Debray. The differences arise probably partly from the different state of aggrega-
tion, and partly f^om the contamination of Wohler's metal with platinimi and potassium.
Berzelius effected the solution of the beryl by fusing the finely-powdered
beryl with three times its weight of carbonate of potash in a platinum crucible, and
B B 3
374 GLUCmUM.
then treating the fused mass with hydrochloric acid ; but the swelling np of the mixture
of carbonate of potash and beryl at the moment of fusion, preyeifts large quantities
being made at a time. To obviate this, Debray uses lime. The following is the pro-
cess given by him.
The pulverised emerald is mixed with half its weight of quick-lime in powder ; the
mixture is then fused in an earthen crucible placed in a wind-farnace ; the tempera-
ture at which the fusion takes place is much lower than that required for the assay of
iron. The glass thus obtained is powdered and moistened with water acidulated with
nitric acid, so as to obtfun a thick paste, to which is added concentrated nitric acid,
taking care to stir the mass, which is converted, in the cold, but better by Jieat, into
an homogeneous jelly ; this is evaporated to drive off the excess of acid, then heated
so as to decompose the nitrates of almuina, glucina, and iron. It is advisable to raise
the temperature at the end of the operation so as to decompose a small portion of th^
nitrate of lime. The result of this calcination is composed of insoluble silica, alumina,
glucina, and sesquioxide of iron, insoluble in water, finally nitrate of lime, and a little
free lime. It is boiled with water containing some chloride of ammonium.
The nitrate of lime is rapidly removed by the water, and the lime decomposing the
chloride of ammonium is zdso at length dissolved, with liberation of ammonia. This
disengagement of ammonia ceases as soon as all the lime is dissolved, and as it is the
surest guarantee of the non- solution of the alumina and glucina, the calcination of the
nitrates should be repeated, unless ammonia is liberated under the circumstances just
mentioned. The residue of silica, alumina, glucina, and iron is well washed until
all the lime is removed, which is known by oxalate of ammonia causing no cloudi-
ness in the washings. The separation of the silica and the earths is easily effected,
mere boiling with nitric acid dissolving the alumina, glucina, and iron, and leaving the
silica undissolved. The solution of the nitrates of alumina, glucina and iron, is then
poured into a solution of carbonate of ammonia, to which a little ammonia has been
added. The precipitation of the earths takes place without liberation of carbonic acid,
and the glucina at length redissolves in the carbonate of ammonia. The solution of
the glucina may be considered complete after seven or eight days* digestion. As the
carl^nate of ammonia may dissolve a little iron, it is better to add to the solution a
a few drops of sulphide of ammonium, which precipitates it completely. The solution
is then filtered and boiled to drive off the carbonate of ammonia, when the glucina is
precipitated in the state of carbonate.
The carbonate of glucina is a dense white powder, easily washed ; it is collected on
a filter and dried.
From the carbonate any of the other compounds of glucina may be easily prepared ;
simple calcination converts it into glucina. A process for the separation of alumina
and glucina has been proposed oy M. Berthier ; it consists in suspending the well
washed earths in water, and passing a current of sulphurous acid through them. Their
solution is complete. The liquid is then boiled to expel the excess of sulphurous acid,
when a dense sub-sulphite of alumina is precipitated, leaving the glucina in solution.
Debray found that sometimes in this process the glucina was entirely precipitated with
the alumina.
Glucina thus obtained possesses the following properties.
It is a light white powder, without smell or taste. Infusible, but volatilises just as
zinc and magnesia. Heat does not harden glucina as it does alumina, but renders it
nevertheless insoluble in acids. Boiling concentrated sulphuric acid dissolves it
easily, but the action of nitric acid is very feeble when the glucina has been strongly
heated. Caustic potash dissolves it readily; and glucina is even capable of expelling
the carbonic acid from carbonate of potash ; it is again precipitated from its solution
in potash by boiling when diluted to a certain extent.
Ehelmen has obtained it in hexagonal prisms by submitting a solution of glucina, in
fused boracic acid, to a powerful and long-continued heat It may likewise be obtained
in microscopic crystals by a more easy process, which consists in decomposing the
sulphate of glucina at a high temperature, in the presence of sulphate of potash ; also
by calcining the double carbonate of glucina and ammonia. The crystals are separated
from the sulphate of potash by washing.
The hydrate of glucina is obtained by precipitating a salt of that base by ammonia.
The presence of ammoniacal salts does not hinder the precipitation. When recently
prepared it greatly resembles the hydrate of alumina ; only it absorbs, by drying m
the air, a notable quantity of carbonic acid.
The hydrate of glucina easily loses its water by heat, and becomes then insoluble
in carbonate of ammonia, the hydrate when pure being very soluble in it ; bat its
solution is hindered by the presence of alumina, in which case, it is only complete after
several hours* digestion. It is also soluble in sulphurous acid and bisulphite of ammonia.
Glucina precipitated from some of its solutions by ammonia, is r^issolved by pro-
GLUCmUM. 375
longed ebullition, but this u observed more especially wben precipitated from the oxa-
late or acetate of ^lucina.
Chlonde ofgluctHum^ is prepared by the same process as the chloride of aluminium,
merely snbstituting glncina for alumina, and at first sight yery much resembles it ; it
is, howeyer, much less volatile than chloride of aluminium, being about as volatile as
chloride of zinc. It differs also from chloride of aluminium masmuch as it is not
capable of forming definite compounds with some protochlorides ; chloride of alumi-
nium uniting with certain protochlorides forming a series of compounds, fhsible at a
low temperature, volatile at a red heat without decomposition ; and the composition of
which is represented by the formula Al*Cl' + MCL The crystals of chloride of alu-
minium may be called chlorinated spioelles, and are easily obtained, it being only
necessary, in order to form the sodium compound of the group, to mix the chloride of
aluminium with half its weight of common uJt, and distil, one distillation producing it
pure, the formula of it being Al^Cl* + NaCL Chloride of ^lucinum is very soluble in
water ; it may, however, be obtained in crystals, by allowmg its solution to evaporate
oyer sulphunc acid under a bell jar. The presence of a little free hydrochloric acid
favours the crystallisation. Thus obtained, this salt is a hydrate, and according to
Awdejew its formula is 61C1 -f 4llO. The hydrated chloride of glucinnm is decom-
posed by heat into hydrochloric acid and glucina.
lodifk o/glucinuwu — This compound presents all the characters of the chloride, only
being a little less volatile. The affinity of iodine for glucinnm, is not very strong,
oxygen decomposing the iodide at the heat of a spirit lamp, liberating iodine and form-
ing glucina.
Glucinnm is also capable of combining with fluorine ; the double fluoride of
glucinnm and potassium being formed by pouring a solution of fluoride of potassium
into a salt of glucina. It is but little soluble in the cold, and is deposited in the form
of brilliant scales.
Sulphate of glucina, — This salt is white, has an acid and slij^htly sweet taste. It
is unalterable in the air at ordioary temperatures but effloresces in dry and warm air.
By heat, it first fuses, in its water of crystallisation, then at a red heat is decomposed
into sulphurous acid, oxygen, and glucina.
Water at 57*2^ F, (14^ C.) dissolves about its own weight of this salt ; its solubility
is increased by heat, and boiling water dissolves an indefinite quantity. The presence
of free sulphuric acid or alcohol lessens its solubility.
It loses a portion of its acid in many cases with facility ; for instance, we obtain
an uncrystallisable tribasic sulphate of glucina, by dissolving carbonate of glncina in a
concentrated solution of the sulphate ; carbonate of glucina is added until carbonic acid
ceases to be liberated at each addition ; the liquid filtered and evaporated gives a gummy
residue. The very dilute solution of this salt lets fall some glucina, and is changed
into a bibasic sulphate, also uncrystallisable.
Sulphate of glucina dissolves zinc with disengagement of hydrogen, forming a
bibasic sulphate of glucina and sulphate of zinc. Sulphate of alumina, under the same
circumstances, dissolves zinc with liberation of hydrogen, and forms a sulphate of zinc .
and an insoluble subsulphate of alumina. Taking advantage of this difference, Debray
proposed a method (^Ann, Chym, et Phjft. xliv. 26), for the separation of alumina and
glucina, but which does not answer for analytical purposes, as chemically pure zinc
is-only acted on with great difficulty by these sulphates. Sulphate of glucina is formed
by dissolving the carbonate in dilute sulphuric acid, the evaporated liquid depositing
it on cooling. It is essential to keep the liquid distinctly acid; it assists the crystal-
lisation, and besides, if we were to dissolve the carbonate in it until the liberation of
carbonic acid ceased, we should obtain a basic uncrystallisable salt According to
Awdejew the formula of this salt is
G10,S0«+4H0.
Double sulphate of glucina and potash. — This salt was discovered by Awd^ew ; he
obtained it while endeavouring to produce the double sulphate of glucina and potash
corresponding to conmion alum (which, had he succeeded, would have been one of
the best proofs of the analogy existing between alumina and glncina).
It is obtained in crystalline crusts, by evaporating a solution containing 15 parts of
sulphate of glncina to 14 parts of sulphate of potash. The concentration is stopped
as soon as the liquid becomes turbid ; at the end of a few hours this salt is deposited,
which is purified by recrystallisation. It is precipitated as a crystalline powder by
the addition of sulphuric acid to the concentrated solution. It is but little soluble in
the cold, much more so, though slowly, in hot water. By the action of heat it first
fnaes in its water of crystallisation, then is decomposed entirely into glncina and sul-
phate of potash, if the heat is strong and long enough applied. Its composition is re-
presented by the formula
G10,8CP + KO,SO* 4 2HO.
B B 4
376 GLUE.
Carbonate ofghcina. — Glucioa is soluble in carbonate of ammonia. When the sola-
tion is boiled, carbonate of ammonia is driven off, and a precipitate of carbonate of
glncina is formed, the composition of which seems to be
3G10,CO« + 5HO;
but if we arrest the boiling as soon as the solution becomes turbid, we obtain a solution
of a double carbonate of glucina and ammonia, from which, by the addition of alcohol,
this salt is deposited in clear crystals. Double carbonate of glucina and ammonia is
white, very soluble in cold water, but is easily decomposed by hot water, liberating
carbonate of ammonia and depositing carbonate of glucina. It is much less soluble in
dilute alcohol, and nearly insoluble in absolute alcohoL It is easily decomposed by-
hear, leaving as a residue pure glucina.
It is also decomposed by exposure to the air after some time. According to Debray
the formula of this salt is
4G10.3CO«HO + 3(NH*0,C0«)
There also exists a double carbonate of potash and glucina corresponding to this salt,
and is prepared by the same process, merely substituting carbonate of potash for car-
bonate of ammonia ; the carbonate of potash, however, takes longer to dissolve the
glucina than carbonate of ammonia.
Oxalic acid dissolves glucina but does not yield any crystallisable compounds, except
in combination with other oxalates, as the oxalate of potash or ammonia.
These double salts crystallise well and have the following simple composition: <-
G10,C«0» + KO,C«0»;
G10,C'0'+NH*0,C«0».
These salts are obtained by dissolving carbonate of glncina in binoxalate of ammonia
or potash in the cold, until carbonic acid ceases to be given off. They decrepitate by
the application of heat The composition of glucina is still undecided ; Berxelius re-
garding it as a sesquioxide, and Awdejew and others as a protoxide. The latter view
gives greater simplicity in the formula of its compounds, but glucina has no decided
analogy to the ordinary class of protoxides, lime and magnesia, &c. — H. K B.
GLUCOSE. The name given to grape and starch sugar by M. Dumas. See
SOQAR.
GLUE {Colle forte, Fr. ; Xeim, Tiachlerleim, Germ.) is the chemical substance gela-
tine in a dry state. The preparation and preservation of the skin and other animal
matters employed in the manufacture of glue, constitute a peculiar branch of industry.
Those who exercise it should study to prevent the fermentation of the substances, and
to diminish the cost of carriage by depriving them of as much water as can conveniently
be done. They may then be put in preparation by macerating them in milk of lime,
renewed three or four times in the course of a fortnight or three weeks. This process
is performed in large tanks of masonry. They are next taken out with all the adhering
lime, and laid in a layer, 2 or 3 inches thick, to drain and dry, upon a sloping pave-
ment, where they are turned over by prongs two or three times a day. The action
of the lime dissolves the blood and certain soft parts, attacks the epidermis, and dis-
poses the gelatinous matter to dissolve more readily. When the cleansed matters are
dried, they may be packed in sacks or hogsheads, and transported to the glue manu-
factory at any distance. The principal substances of which glqe is made are the
parings of ox and other thick hides, which form the strongest article, the refuse of
the leather dresser ; both afford from 45 to 55 per cent of glue. The tendons, and
many other offals of slaughter-houses, also afford materials, though of an inferior
quality, for the purpose. The refuse of tanneries, such as the ears of oxen, calves,
sheep, &c., arc better articles ; but parings of parchment, old gloves, and, in fact,
animal skin in every form, uncombined with tannin, may be made into glue.
The manufacturer who receives these materials is generally careful to ensure their
purification by subjecting them to a weak lime steep, and rinsing them by exposure
m baskets to a stream of water. They are lastly drained upon a sloping surface and
well turned over till the quicklime gets mild by absorption of carbonic acid ; for, in
its caustic state, it would damage the glue at the heat of boiling water. It is not
necessary, however, to dry them before they are put into the boiler, because they dis-
solve faster in their soft and tumefied state.
The boiler is marie of copper, rather shallow in proportion to its area, with a uniform
fiat bottom, equably exposed all over to the flame of the fire. Above the true bottom
there is a false one of copper or iron, pierced with holes, and standing upon feet 3 or
4 inches high ; which serves to sustain the animal matters, and prevent them from
being injured by the fire. The copper being filled to two-thirds of its height with
soft water, is then heaped up with the bulky animal substances, so high as to surmount
its brim. But soon after the ebullition begins they sink down, and, in a few- hours,
get entirely immersed in the liquid. They should be stirred about from time to time,
GLUE. 377
mnd well pr«*aed down towards the biM bottom, while n ttaij but gentle loll ii
nuuntained.
The aoiatioa mnit be drawD off in nieoewTe portioni ; a method which fVaetioiis
the products, or (obdividei them into articlei of Tanoot viloe, gradnallj decreaiing
from the first portion drawn off to the last It has been aseertained h; careful expe-
riments that gelatine ^et« altered orer the fire yer? soon after it is diasolTcd, if the
beat of !12° ig malQlamed, and it oaght therefore to be drawn off whenever it Issnffl-
eientlf fluid and strong for forming a clear gelatinons moss on coaling, capable of
being eat into moderately Arm lUcea by the wire. The point is commonly determined
by filling half an egg-shell with the liqnor, and exposing it to (he air to cooL The
jell; ought to gel very eon siateat in the course of a few minates; ifnot so, the boiling
most be persisted in a Ultle longer. When this term is attained, the fire is smothered
np, and the contents of the boiler are lotl to settle iiir a quarter of an honr. The slop-
cock being partially turned, alt the thin gelstinoos liquor ii run off into a deep boiler,
immened in a warm water t>ath, lo that it may continue hot and fluid for several
hours. At the end of this time (he sapernatsnt clear liquid is to be drawn off into
congealing boxes, as will be presently eiplained.
The grounds, or nndissoived matters in the boiler, are to be again supplied with a
qnantity of boiling water fWira an adjoining copper, and are to be once more snbjected
to the action of the Ere, till the contents asmme the appcaranue of dtsaoWed jelly, and
afford a treA quantity of strong glae liquor, bj the stop-cock. The gronnds should
1>e subjected a third time to this operation, after which they may be put into a bag,
and squeeaed in a press to leave nothing unextracted. The Utter solnuons are nsoallf
too weak (o form glue directly, but they may be strengthened by boiling with a por-
tion of fresh skin-parings.
Fiy. 918 represents a coaveDiGnt apparatus Cir the boiling of skint into gl>M, in
upon by the waste beat of the chimney, pro-
way ; the second contains tbe crude materials, with water for dissolving them; and the
third receives the solution to be settled. The last vessel is doable, with water con.
tsined between the outer and inner one ; and discharges ita contents by a ttop-cock
into buckets for filling the gelatinising wooden boxes. The last made solstioo hat
abontoDC-five-hnndredtbpartofslnmin powder osually added to it, with proper agita-
tion, after which it is left to settle for several boors.
The three successive boils furnish three different qualities of glue.
Flanders or Dutch glue, long much esteemed on the Continenl, w»« made in the
manner above described, but at two boils, fWim animal o&ls well washed and soaked,
so as to need less boiling. The liquor being drawn off thinner, waa therefore less
coloured, and being made into thinner plates WM very tranapMent Hie above two
boils gave two qualities of glae.
By the English practice, -the whole of the animal matter is brought into solation at
once, and (he liquor being drawn off, hot waler is poured on the residoum, and made
to boil on it for some time, when the liquor thus obtained is merely used instead of
water upon a fresh quantity of glue roaterials. Tbe first drawn off liquor is kept hot
in a setUIng copper for five hours, and then the clear solation is drawn off into the
878 GLUE.
These boxes are made of deal, of a square form, but a little narrower at bottom tiiaa
at top. When very regular cakes of glue are wished for, cross grooves of the desired
square form are cut in the bottom of the box« The liquid glue is poured into the
boxes placed very level, through funnels furnished with filter cloths, till it stands ai
the brim of each. The apartment in which this is done ought to be as cool and drj
as possible, to favour the solidification of the glue, and should be floored with stone
flags kept very clean, so Uiat if any glue run through the seams, it may be recovered.
At the end of 12 or 18 hours, or usually in the morning if the boxes have been filled
over-night, the glue is sufficiently firm for the nets, and they are at this time removed
to an upper story, mounted with ventilating windows to admit the air from all quar-
ters. Here the boxes are inverted upon a moistened table, so that the gelatinous
cake thus turned out will not adhere to its surface ; usually the moist blade of a long
knife is insinuated round the sides of the boxes beforehand, to loosen the glue. The
mass is first divided into horizontal layers by a brass wire stretched in a frame, like
that of a bow'Saw, and guided by rulers which are placed at distances corresponding
to the desired thickness of the cske of glue. The lines formed by the grooves in the
bottom of the box define the superficisd area of each cake, where it is to be cut with
a moist knife. The gelatinous layers thus formed, must be dextrously liited, and
immediately laid upon nets stretched in wooden frames, till each frame be filled.
These frames are set over each other at distances of about three inches, being supported
by small wooden pegs, stuck into mortise holes in an upright, fixed round the room ; so
that the air may have perfectly free access on every side. The cakes must more*
over be turned upside down upon the nets twice or thrice every day, which is readily
managed, as each frame may be slid out like a drawer, upon the pegs at its two
sides.
The drying of the glue is the most precarious part of the manufacture. The least
disturbance of the weather may injure the glue during the two or three first days of
its exposure ; should the temperature of the air rise considerably, the gelatine may
turn so soft as to become unshapely, and even to run through the meshes upon the
pieces below, or it may get attached to the strings and surround them, so as not to
be separable without plunging the net into boiling water. If frost supervene, the
water may freeze and form numerous cracks in the cakes. Such pieces most be im-
mediately re-melted and re-formed. A slight fog even produces upon glue newly
exposed a serious deterioration ; the damp condensed upon its surfice occasioning a
general mouldiness. A thunderstorm sometimes destroys the coagulating power in
the whole lamina: at once ; or causes the glue to turn on the nets, in the language
of the manufacturer. A wind too dry or too hot may cause it to dry so quickly, as to
prevent it from contracting to its proper size without numerous cracks and fissures.
In this predicament, the closing of all the flaps of the windows is the only means of
abating the mischiei On these accounts it is of importance to select the most tem-
perate season of the year, such as spring and autumn, for the glue manufacture.
After the glue is dried upon the nets it may still preserve too much flexibility, or
softness at least, to be saleable ; in which case it must be dried in a stove by arti-
ficial heat This aid is peculiarly requisite in a humid climate, like that of Great
Britain.
When sufficiently dry it next receives a gloss, by being dipped, cake by cake, in hot
water, and then rubbed with a brush, also moistened in hot water ; after which the
glue is arranged upon a hurdle, and transferred to the stove room, if the weather be
not sufficiently hot. One day of proper drought will make it ready for being packed
up in casks.
The pale coloured, hard, and solid article, possessing a brilliant fhicture, which is
made from the parings of ox-hides by the first process, is the best and most cohesive,
and is most suitable for joiners, cabinet-makers, painters, &c. But many workmen
are influenced by such ignorant pr<judices, that they still prefer a dark-coloured
article, with somewhat of a fetid odour, indicative of its impurity and bad preparadcm,
the result of bad materials and too long exposure to the boiling heat.
There is a good deal of glue made in France from bones f^ed from the phosphate
of lime by muriatic acid. This is a poor article, possessing little cohesive force. It
dissolves almost entirely in cold water, which is the best criterion of its imperfection.
Glue should merely soften in cold water, and the more considerably it swells, the
better, generally speaking, it is.
Some manufacturers prefer a brass to a copper pan for boiling glue, and insist much
on skimming it as it boils; but the apparatus represented renders skimming of little
consequence. For use, glue should be broken into small pieces, pnt along with some
water into a vessel, allowed to soak for some hours, and subjected to the heat of a
boiling-water bath, but not boiled itself. The surrounding hot water keeps it long
in a fit state for joiners, cabinet-makers, &c
GLTCERINE. 379
Water containing only one-hnndredth part of good glne, forms a tremnlont solid.
When the solution, however, is heated and cooled several times, it loses the property
of gelatinising, even thongh it be enclosed in a vessel hermetically sealed. Isinglass
or fish glue undergoes the same change. Common glue is not soluble in alcohol, but
is precipitated in a white, coherent, elastic mass, when its watery solution is treated
with that fluid. By transmitting chlorine gas through a warm solution of glue, a
combination is very readily effected, and a viscid mass is obtained like that thrown
down by alcohol. A little chlorine suffices to precipitate the whole of the glue.
Concentrated sulphuric acid makes glue undergo remarkable changes ; during which
are produced sugar of gelatine, leucine, an animal matter, &c. Nitric acid, with the
aid of heat, converts glue into malic acid, oxalic acid, a fat analogous to suet, and into
tannin ; so that. In this way, one piece of skin may be made to tan another. When
the mixture of ^lue and nitric acid is much evaporated, a detonation at last takes place.
Strong acetic acid renders glue first soft and transparent, and then dissolves it Though
the solution does not gelatinise, it preserves the property of glueing surfaces together
when it dries. Liquid glue dissolves a considerable quantity of lime, and also of the
phosphate of lime recently precipitated. Accordingly glue is sometimes contaminated
with that salt Tannin both natural and artificial combines with glue; and with such
effect, that one part of glue dissolved in 5000 parts of water affords a sensible preci-
pitate with the infusion of nutgalls. Tannin unites with glue in several proportions,
which are to each other as the numbers !» 1^, and 2; one compound consists of 100
glue and 89 tannin ; another of 100 glue and 60 tannin ; and a third of 100 glue and
120 tannin. These two substances cannot be afterwards separated from each other
by any known chemical process.
Glue may be freed from the foreign animal matters generally present in it, by soft-
ening it in cold water, washing it with the same several times till it no longer gives
out any colour, then bruising it with the hand, and suspending it in a linen bag beneath
the surface of a large quantity of water at 60^ F. In this case, the water loaded with
the soluble impurities of the glue gradually sinks to the bottom of the vessel, while
the pure glue remains in the bag surrounded with water. If this softened glue be
heated to 92^ without adding water, it will liquefy; and if we heat it to 122^, and
filter it, some albuminous and other impurities will remain on the filter, while a colour-
less solution of glue will pass through.
Experiments have not yet explained how gelatine is formed fVom skin by ebullition.
It is a change somewhat analogous to tbat of starch into gum and sagar, and takes
place without any appreciable disengagement of gas, and even in close vessels. GeU-
tine, says Berzelius, does not exist in the living body, but several animal tissues, such
as skin, cartilages, hartshorn, tendons, the serous membranes, and bones, are suscep-
tible of being converted into it See Gklattne.
GLUTEN (^CoUe Vegetale and Gluten, Fr.; KUber, Germ.) was first extracted by
Beccaria from wheat flour, and was long regarded as a proximat^riociple of plants,
till Einhoff, Taddei, and Berzelius succeeded in showing that it may be resolved by
means of alcohol into three different substances, one of which resembles closely animal
albumine, and has been called Zymome, or vegetable albumine ; another has been
called Gliadine; and a third Mucine,
Gluten, when dried in the air or a stove, diminishes greatly in size, becomes hard,
brittle, glistening, and of a deep yellow colour. It is insoluble in ether, in fat and
essential oils, and nearly so in water. Alcohol and acetic acid cause gluten to swell
and make a sort of milky solution. Dilute acids and alkaline lyes dissolve gluten.
Its ultimate constituents are not determined, but azote is one of them, and accordingly
when moist gluten is left to ferment, it exhales the smell of old cheese.
Some ^ears since, M. E. M. Martin, of Vervins, proposed to extract the starch
without injuring the gluten, which then becomes available for alimentary purposes.
His process is a mechanical one (resembling that long practised in laboratories for
procuring gluten), and consists in washing wheat flour, made into a paste, with water,
either by the hand or machinery.
The gluten thus obtained is susceptible of numerous useful applications for alimen-
tary purposes. Mixed with wheat flour, in the proportions of 30 parts of flour, 10 of
fresh gluten, and 7 of water, it has been employed to produce a superior sort of maca-
roni, vermicelli* and other kinds of Italian pastes ; and MM. Yeron Fr«^res, of Paris,
have made with it a new sort of paste, which they have termed granvlated gluten
(gluten granule).
GLYCERINE is a sweet substance extracted fh>m fatty substances. It may be
prepared in the utmost purity by the following process : — If we take equal parts of olive
oil and finely-ground litharge, pat them into a basin with a little water, set this on a
sand bath moderately heat^, and stir the mixture constantly, with the occasional
addition of hot water to replace what is lost by evaporation, we shall obtain, in a short
380 GOBELIN MANUFACTORY.
time, a soap or plaster of lead. If, after haviDg added more water to this, we lemoye
the vessel from the fire, decant the liquor, filter it, pass solpharetted hydrogen through
it to separate the lead, then filter afresh, and concentrate the liquor as much as pos-
sible without burning, upon the sand-bath, we obtain glycerine ; but what remains
mast be finally evaporated within the receiver of the air-pump. Glycerine thus pre-
pared is a transparent liquid, without colour or smell, and of a syrupy consistence: It
has a very sweet taste. Its specific gravity is 1*27 at the temperature of 60°. When
thrown upon burning coals, it takes fire and bums like an olL Water combines with
it in almost all proportions ; alcohol dissolves it readily ; nitric acid converts it into
oxalic acid ; and, according to Vogel, sulphuric acid transforms it into sugar, in the
same way as it does starch. By yeast it becomes acid by the formation of formic and
metacetic acids.
Its constituents are, carbon 40, hydrogen 9, oxygen 51, in 100.
Glycerine is one of the products of the saponification of fat oils. It is produced in
large quantities in the soap manufactories in a very impure state, being contaminated
with saline and empyreumatic matters, and having a very strong disagreeable odour.
In order to obtain glycerine from this source, the residuary liquors are evaporated and
treated with alcohol, which dissolves out the glycerine. The alcohol having been
separated by evaporation, the glycerine is diluted with water, and boiled with animal
charcoal. This process must be repeated several times, or until the result is suffi*
ciently free from smell. It is, however, difficult to obtain pure glycerine from this
source, on account of the nature and condition of the ingredients usually employed in
making soap, which it is almost impossible to deprive of rancid odour.
The compounds of glycerine with the fatty acids constitute the various kinds of fate
and oils, but the base does not appear to have the same composition in alL A certain
quantity of water appears to separate, and the equivalent of glycerine to be in some
fats but half what it is in others. Thus the glycerine of the palm oil has the formula
CH^C, and the glycerine of myristine, or nutmeg butter, CHH), of which bodies
the common glycerine should be the hydrate.
Glycerine is now obtained in great quantities from palm oil, in the process of pun*
fication for candles. It is employed with much advantage to preserve soft bodied
animals. It is manufactured into soap, is administered internally, and is supposed to
possess highly nutritive properties. It has been employed in cases of deafiiess, and in
diseases of the throat. By some it is used to preserve collodion plates in a state of
sensitiveness for many days.
GLTPHOGRAPHY. A process introduced some years since to cheapen wood
engraving. A metal plate was covered with a thick etching-ground, and an etching
mside through to the metal in the usual manner. Several coats of ink were then
applied by means of a small composition roller. This adheres only to the varnish.
When the hollows are deep enough, the plate is placed in connection with a voltaic
battery, and copped is deposited m the usual way (see Electro-Metajxurgt) ; the
result being a plate with the drawing in relief. The process is rarely practised.
GNEISS may be called stratified, or, by those who object to that term, foliated
granite, being formed of the same materials as granite, namely, felspar, quartz, and
mica. — Lyell.
Gneiss might indeed, in its purest and most typical form, be termed schistose
granite, consisting, like granite, of felspar, quartz, and mica ; but having those minerals
arranged in layera or plates, rather than in a confused aggregation of crystals.— JifAet.
.In whatever state of aggregation the particles of gneiss may have been originally
deposited, we know now that it is a hard, tough, crystalline rock, exhibiting curved
and twisted lini'S of stratification, and composed in the main of quartz, felspar, mica,
and hornblende. Mineralogically speaking, it differs from the granite rocks with
which it is associated chiefly in this, that while the crystals of quartz, felspar, &c., are
distinct and entire in granite, in gneiss they are broken, water-worn, and confusedly
sggregated. Hence the general belief is, that gneiss or gneissose rocks are but the
particles of granite weathered and worn, carried down by streams and rivers, and
deposited in the seas of that early period. — Page.
GOBELIN MANUFACTORY. This establishment, which has been long cele-
brated for its tapestry, took its name from the brothers Gobelin. Giles Gobelin, a
dyer at Paris, in the time of Francis I., had found out an improvement in the then
usual scarlet dye ; and as he had remarked that the water of the rivulet Bievre, in the
suburbs of St. Marceau, was excellent for his art, he erected on it a large dye house,
which, out of ridicule, was called Fdie-GoMins (^Rabelais). About this period a
Flemish painter, whom some name Peter Roek, and others Kloek, and who had
travelled a long time in the East, established, and continued to his death in 1550, a
manufactory for dyeing scarlet cloth by an improved process. Through the means
of Colbert, minister of Louis XIV., one of the Gobelins learned the process nsed for
GOLD. 381
preparing the Gennan scarlet dye from one Glnck, whom some contider to be Golich
(who waa said to have learned to d^e scarlet from one Knffelar, a dyer at Leyden),
and others as Kloek ; and the Parisian scarlet dye soon rose into so great repute that
the populace imagined that Gobelin had acquired the art from the deviL It is known
that Louis XIV^ by the advice of Colbert, purchased Gobelin's building from his suc-
cessors in 1667, and transformed it into a palace, to which he gave the name of Hotel
Royal de» Gobeiins, and which he assigned for the use of first-rate artists, particularly
painters, jewellers, weavers of tapestry, and others. — Beckmann,
The national manu&ctory is now alone remarkable for its production in textile
manufacture of some of the finest works of art ; and not only does it excel in the high
character of its designs, but also in the brilliancy and permanence of its cohura.
GOLD. (Eng. and Germ.; Or^ Fr.) This metal is distinguished by its splendid
yellow colour; its great density » 19-3 compared to water 1*0; its ftisibiiity at the
32nd degree of Wedgewood's pyrometer ; its pre-eminent ductility and malleability,
whence it can be beaten into leaves only l-282,000th of an inch thick; and its insolu-
bility in any acid menstruum, except the mixture of muriatic and nitric acids, — styled
by the alchemists aqua regia, because gold was deemed by them to be the king of
metals, — or in solutions of chlorine.
Gold is found only in the metallic state, sometimes crystallised in the cube, and its
derivative forms. It occurs also in threads of various sixes, twisted and interlaced into
a chain of minute octahedral crystals ; as also in spangles or rounded grains, which
when of a certain magnitude are called pepitaa. The small grains are not fragments
broken from a greater mass; but they show by their flattened ovoid shape and their
rounded outline that this is their original state. The spec. grav. of native gold varies
from 13*3 to 17*7. Humboldt states that the largest pepita known was one found in
Peru weighing about 12 kilogrammes (26^ lbs. avoird.) ; but masses have been quoted
in the province of Quito which weighed nearly four times as much. Some of the
** nuggets " from Australia have greatly exceeded this.
Another ore of gold is the alloy with silver, or argental gold, the eketrttm of Pliny.
It seems to be a definite compound, containing in 100 parts, 64 of gold and 86 of
silver.
The mineral formations in which this metal occurs are the crystalline primitive
rocks, the compact transition rocks, the trachytic and trap rocks, and alluvial grounds.
Sir Roderick Murchison says, in his chapter On the Original Formation of Gold, in
his ''Silnria:** — *' We may first proceed to consider the nature and limits of the rich
gold-bearing rocks, and then offer proofs, that the chief auriferous wealth, as derived
from them, occurs in superficial detritus. Appealing to the structure of the different
mountains, which at former periods have afforded, or still afford, any notable
amount of gold, we find in all a general agreement. ' Whether, referring to past
history, we cast our eyes to the countries watered by the sources of the Golden Tagus,
to the Phrygia and Thrace of the Greeks and Rmnans, to the Bohemia of the Middle
Ages, to tracts in Britain which were worked in old times, and are now either
abandoned, or very slightly productive, or to those chains in America and Australia
which, previously unsearcbed, have in our times, proved so rich, we invariably find
the same constants in nature. In all these lands, gold has been imparted abundantly
to the ancient rocks only, whose order and succession we have traced, or their
associated eruptive rocks. Sometimes, however, it is also shown to be diffused
through the body of such rocks, whether of igneous or of aqueous origin. The stratified
rocks of the highest antiquity, such as the oldest gneiss and quartz rocks (like those,
for example, of Scandinavia and the northern Highlands of Scotland), have very
seldom borne gold ; but the sedimentary accumulations which followed, or the Silurian,
Devonian, and carboniferous (particularly the first of these three) have been the
deposits which, in the tracts where they have undergone a metamorphosis or change
of structure by the influence of igneous agency, or other causes, have been the chief
sources whence gold has been derived."
Gold is usually either disseminated, and as it were impasted in stony masses, or
spread out in thin plates or grains on their surface, or, lastly, implanted in their
cavities, under the shape of filaments or crystallised twigs. The minerals composing
the veins are either quartz, calcspar, or sulphate of baryta. The ores that accompany
the ^Id in these veins are chiefly iron pyrites, copper pyrites, galena, blende, and
mispickel (arsenical pyrites).
In the ores called auriferous pyrites, this metal occurs generally in an invisible
form ; but though invisible in the fresh pyrites the gold becomes visible by its decom-
position ; as the hydrated oxide of iron idlows the native gold particles to shine forth
ou their reddish-brown ground, even when the precious metal may constitute only the
five millionth part of its weight, as at Rammelsberg in the Hartz. In that state it has
been extracted with profit ; most frequently by amalgamation with mercury, proving
882 GOLD.
that the gold was in the native tftate, and not in that of a stilphnret The iron pyrites
of Wicklow, and of some of oar English mines contain gold. After the sulphar of
the ore has been separated in the process of manofactaring solphuric acid, the
residuary niass, called ** sulphar cake," is roasted with common salt. This is thrown
into hot water, the copper which is present, is dissolved as muriate of copper. The
silver present has been converted by the roasting process into a chloride ; this is
dissolved out with a strong brine, from which the silver is precipitated by zinc. The
silver cake obtained in this way is sold from prices varying from 6s. to 10s. the ounce
the additional sum above 5«. 6d, the oance for pure silver being given for the gold
it contains.
Gold exists among the primitive strata, disseminated in small grains, spangles, and
crystals. Brazil affords a remarkable example of this species of gold mine. Beds of
granular quartz, or micaceous specular iron, in the Sierra of Codies, 12 leagues beyond
Villa Rica, which form a portion of a mica-slate district, includes a great qnaotity of
native gold in spangles, which in this ferruginous rock replace mica.
The auriferous ores of Hungary and Transylvania, composed of tellnriunou silver
pyrites or sulpharet of silver, and native gold, lie in masses or powerful veins in a rock
of trachyte, or in a decomposed felspar subordinate to it Such is the locality of the
gold ore of Ronigsberg, of Telkebanya, between Eperies and Tokay in Hungary, and
probably that of the gold ores of Kapnick, Felsobanya, &c., in Transylvania ; an arrange-
ment nearly the same with what occurs in Equatorial America. The auriferous veins
of Guanaxuato, of Real del Monte, of Villalpando, are similar to those of Schemnitz
in Hungary, as to magnitude, relative position, the nature of the ores they include,
and of the rocks they traverse. These districts have impressed all mineralogists with
the evidences of the action of volcanic fire. Breislak and Hacquet have described the
gold mines of Transylvania as situated in the crater of an ancient volcano. It is
certain that the trachytes which form the principal portions of the rocks including
gold, are now almost universally regarded as of igneous or volcanic origin.
It would seem, however, that the primary source of the gold is not in these rocks,
but rather in the sienites and greenstone porphyries below them, which in Hungary
and Transylvania are rich in great auriferous deposits ; for gold has never been
found in the trachyte of the Euganean mountains, of the mountains of the Vicentin, or
of those of Auvergne ; all of which are superposed upon granite rocks, barren in
metaL
Finally, if it be true that the ancients worked mines of gold in the island of Ischia,
it would be another example, and a very remarkable one, of the presence of this metal
in trachytes of an origin evidently volcanic.
Gold is, however, much more common in the alluvial grounds than among the
primitive rocks just described. It is found disseminated in the siliceous, argillaceous,
and ferruginous sands of certain plains and rivers, especially in their re-entering
angles, at the season of low water, and after storms and temporary floods. On the
occurrence of gold. Dr. Ure remarks : " It has been supposed that the gold found in
the beds of rivers had been torn out by the waters from the veins and prmutive rocks,
which they traverse. Some have even searched, but in vain at the source of auri*
ferons streams for the native bed of this previous metal. The gold in them belongs,
however, to the grounds washed by the waters as they glide along. This opinion,
suggested at first by Deli us, and supported by Debom, Guettard, Robitaut, Balbo, &C.,
is founded upon just observations. 1. The soil of these plains contains frequently, at
a certain depth, and in several spots, spangles of gold, separable by washing. 2. The
beds of the aur^erous rivers and streamlets contain more gold after storms of rain
upon the plains than in any other circumstances. 3. It happens almost always that
gold is found among the sands of rivers only in a very circumscribed space ; on as-
cending these rivers their sands cease to afford gold *, though did this metal come from
the rocks above, it should be found more abundantly near the source of the rivers.
Thus it is known that the Oreo contains no gold except from Font to its junction with
the Po. The Ticino affords gold only below the Lago Maggiore, and consequently
far from the primitive mountains, after traversing a lake, where its course is slackened,
and into which whatsoever is carried down from these mountains must have been de-
posited. The Rhine gives more gold near Strasburg than near Basle, though the
latter be much closer to the mountains. The sands of the Danube do not contain a
grain of gold, while this river runs in a mountainous region ; that is, from the frontiers
of thebishoprickof Fassau to Effcrdlng; but its sands become auriferous in the plains
below. The same thing is true of the Ems ; the sands of the upper portion of this
river, as it flows among the mountains of Styria, include no gold ; but from its entrance
mto the plain at Steyer, till its embouchure in the Danube, its sands become auriferous,
and are oven rich enough to be washed with profit.
GOLD. 883
The greater part of the anriferoas sands, in Earope, Asia, AfHea, and America, are
black or red, and consequently fermginoas : a remarkable circamstance in the geolo-
gical position of alluvial gold. M. Napione supposes that the gold of these ferm-
ginooB grounds is due to the decomposition of auriferous pyrites. The auriferous sand
occurring in Hungary, almost always in the neighbourhood of the beds of lignites^ and
the petrined wood covered with gold grains, found buried at a depth of 55 yards in
clay, in the mine of Vorospatak near Abrabanya in Transylvania, might lead us to
presume that the epoch of the formation of the auriferous alluvia is not remote from
that of the lignites. The same association of gold ore and fossil wood occurs in South
America, at Moco. Near the village of Lloro have been discovered, at a depth of 20
feet, large trunks of petrified trees, surrounded with fragments of trap rocks inter-
spersed with spangles of gold and platinum. But the alluvial soil affoi^s likewise all
the characters of the basaltic rocks \ thus in France, the C^ae and the Garden, auri-
ferous rivers, where they afford most gold, flow over ground apparently derived from
the destruction of the trap rocks, which occur m situ higher up the country. This fact
had struck Reaumur, and this celebrated observer had remarked that the sand which
more immediately accompanies the gold spangles in most rivers, and particularly in
the Rhone and the Rhine, is composed, like that of Ceylon and Ezpailly, of black prot-
oxide of iron and saiall grains of rubies, corundum, hyacinth, &c. Titanium has been
observed more recently. It has, lastly, been remarked that the gold of alluvial form*
ations is purer than XhaX extracted from rocks."
Principal Gold Mines,
Spain anciently possessed mines of gold in regular veins, especially in the province
of Asturias ; but the richness of the American mines caused them to be neglected.
Julius Cssar is said to have paid his enormous debts, and have added largely to the
Roman treasury, from the wealth which he derived from the Spanish mines. The
Tagus, and some other streams of that country, were said to roll over golden sands.
France contains no workable gold mines ; but it presents in several of its rivers auri-
ferous sands. There are some gold mines in Piedmont ; particularly the veins of
auriferous pyrites of Macugnagna, at the foot of Monte Rosa, lying in a mountain of
gniiiss ; and although they do not contain 10 or 1 1 grains of gold in a hundred- weight,
they have long defrayed the expense of working them. On the southern slope of the
Pennine Alps, from the Simplon and Monte Rosa to the valley of Aoste, several auri-
ferous districts and rivers occur. Such are the torrent Evenson, which has afforded
much gold by washing ; the Oreo, in its passage from the Pont to the Po: the reddish
grounds over which this little river runs for several miles, and the hills in the neigh-
bourhood of Ohivasso, contain gold spangles in considerable quantity.
In the county of Wicklow, in Ireland, in the year 1796, some fine specimens of
gold were found,-— one mass weighing twenty -two ounces. The gold is found in the
debris of the valley at the base of Croghan-Kinshela ; and it would appear to be derived
from the granite of that mountain, or the homblendic greenstones by which it is tnu
versed. Messrs. Weaver and Mills, however, prosecuted extensive mine workings in
search of the source of the gold without any success. As we have already stated,
the pyrites of Wicklow contain gold, but no auriferous veins have been discovered.
In Cornwall gold has been found in the tin streams of Camon vale, and some few
other spots; and some of the quartz veins traversing the slate have been found
to contain gold. Many of the gossans of the copper lodes are known to have gold
in them ; but it is only in a few rare instances that the precious metal has been
separated.
In Devonshire, near North Molton, at the Britannia mine, gold has been found in
small quantities, associated with the minerals of the district ; but it has never paid the
coat of obtaining it. In Scotland also gold has been found. Pennant says : ** In the
reigns of James IV. and V. of Scotland, vast wealth was procured in the Lead Hills,
from the gold washed from the mountains ; in the reign of the latter not less than the
value of 300,000/. sterling." We are told that in another locality a piece of gold
weighing thirty ounces was found ; but we cannot find any good authority for this
statement.
In North Wales, especially in Merionethshire, the older slaty rocks were declared
some ten years since to be auriferous. Professor Ramsay has examined and described
the district, and especially the mineral and quartz veins of Cwm-eisen-isaf and Dol-
jr-frwynog, which contain gold. This district has been worked for gold for some
time ; but in no case, we believe, to a profit. At Gogofau, not far from Llandovery,
the Romans worked for gold, the remains of their workings being still to be discovered.
They have been described by Mr. W. Warington Smyth in the Memoirs of the
Geological Survey.
384 GOLD.
There are anriferoai nod* !d some riveTt of Svitierland, is the Reiui aad the Aar.
Id Oermuiy no mint of gold is worked, except in the temtorj of Salibarg, anud the
chain of moant^iiii which separate the T;rol and Carinthia.
The mineiof HuDgarjand Transylvania ore Ihe onlf gold miaesofanj importance
in Europe; they are remarkable for their positioo, the peculiar metals that accom-
pan J them, aud their product, estimated at about 1130 pounds aroird. aonually. The
principal ones are in Hoogary, 1, those of Konigsberg; the native gold is dis*e-
minaled ia ores of snlphoret of silver, vbich occur in smalt maiaet and in Teins in a
decnmposing felspar rock, amid a conglomerate of pumice, constituting a portion of
the trachf tic fbrmatlon 1 2, those of Borson, Scbemnitz; and 3, of Felsobuija; ore*
also of auriferons sulphuret of siUer occnr in veins of sienile and greenstiHie por-
phjTj ; 4, those of Telkebanya, to the soath of Kaschau, are in a deposit of aDTtferoas
pyrites tunid trap rocks of Ibe most recent formation.
In TransytTsuia Ibe gold occurs in veios, often of great magnitude. These Teins
hare no side pistes or vail stones, but abut, without intermediate gangnea, the primi-
tive rock. They consist of decomposing quarti, ferrllerons limestone, heavj spar,
Baortpar.aDd sulpburet of silver. The mine of Kapnik deserrea notice, where the
sold is associated with orpiment. and that of Vorospntak in granite rocks ; those of
OffenbanTa, Zalatoa, and Nagy-Ag, where it is assorted with Itllurium. The last
is in aienitic r^k on the limits of the trachyte.
In Sweden, the mine of Edelfors in Smoland may be mentioned, where the gold
occors native and in auriferous pyrites i the veina are a brown qoani, in a mooulain
of foliated homstone.
In Siberia, native gold occurs in a homitoDC at Schlangenberg or ZmeoC and at
Zmeino-gank in the Altai mountains, accompanied with many other ores.
The gold mine of Berezovsk in tlie Ural moontains has been long knowtk, Mtisitt-
iag otpartiallji dtcompoted avriferoiit pyritei, disseminated in a vein of grrasf qosni.
This is, according to Hurohison, " the only work at which subterranean minmg in the
solid rock is still practised ; there the shaft traverses a mass of apparently metamor-
phosed and crystalline matrix called ' heresiU,' resembhng a decomposed granite with
veins of quarti, in which some gold is disseminated." About 1S!0, a very rich depoiil
of native gold was discovered on the easleni side of the Ural moontuna, disseminited
at some ;)^rds deep in an arvillaceoos loam, and accompanied with the diiria of
rocks which nsuallj compose the anriferous alluvial soils, as greenstone, serpentine,
protoxide of iron, corundum, &c The riven of this district possess aarifcroia
At the Boimanofsk mines, soutli of Missk, great piles of ancient drift or gravel
bavins been removed for the extraction of gold, the eroded edge* of highly inclined
crystalliDC Umestones have been exposed, which, from being much nearer the centre
of the chain than the above, are probably of Silurian or Devonian age. It is from
the adjacent eruptive serpentinons masses and slaty rocki b that the gold shingle e
(usually most auriferous near the sarfue of the abraded rock a) hn beeQ dermd.
The tops of the highly inclined beds a are in fket rounded off, and the interstiecs
between them worn into holes and caviliea, as if by very powerful action of water.
Now here, as at Bereiovsk, mammoth remains have been found. They were lodged
in the lowest part of the excavation, at the spot marked n, and at abonl fifty tett
beneath the original surface of overlying coarse gravel c, before it was removed by the
workmen fh>m the vacant space aoder the dotted line. The feeble influence of
the streams (n) which now Bow, in excavating even the loose shingle is seen at
the spot marked o, the bed of the rivulet having been lowered hy fttonaa labonr
from its natural level o to lh« marked n for the convenience of the diggers.—
Marchitott.
It wa« from the infillings of one of the gravelly depresnoos between these eleva-
tions, south of Miask, that the largest Inmp of solid gold was fnuad, of which at that
time (1834) there was any record. This "pepita" weighs ninety-six pounds troy,
and is ttiU exhibited in the mofenm of the Imperial School of Mine* at SL Peten-
burg.
GOLD. 385
The qaantity of gold raised in Russia during Ato years was as follows :—
1847 1700 poods.
1848 1660 „
1849 1530 „
1850 1490 „
1851 1266 „
7646
Equal to about 296,932 lbs. troy in five years.— X€cfure« on Goid, R, Hunt
In Erman's ** ArehiTes" we find that in the year 1851, the gold of the Uralian
washing and amalgamation works produced 332 poods ; the Nertschinsk works, 67
poods; the remaining West and East Siberian washings, 1107 poods; the produce of the
Altai Mountains and of Nertschinsk Siberian works, 39 poods; making 1546 poods.
In Asia, and especially in its southern districts, there are many mines, streams^
rivers, and wastes which contain this metal. The Pactolus, a smaJl river of Lydia,
rolled over such golden sands, that it was supposed to constitute the origin of the
wealth of Cnssus. But these deposits are now poor and forgotten. Japan, Formosa,
Ceylon, Java, Sumatra, Borneo, the Philippines, and some other islands of the Indian
Archipelago, are rich in gold streams. Those of Borneo are worked by the Chinese in
an alluvial soil on the western coast, at the foot of a chain of volcanic mountains.
Little or no gold comes into Europe fh>m Asia, because its servile inhabitants place
their fortune in treasure, and love to hoard up that precious metal.
Numerous gold mines occur on the two slopes of the chain of the Cailas mountains
in the Oundds, a province of Little Thibet The gold lies in quartz veins which tra-
verse a very crumbling reddish granite.
Africa was, with Spain, the source of the greater portion of the gold possessed by
the ancients. The gold which Africa still brings into the market ui always in dust,
showing that the metal is obtained by washing the alluvial soils. None of it is col-
lected in the north of that continent ; three or four districts only are remarkable for
the quantity of gold they produce.
The first mines are those of Kordofan, between Darfour and Abyssinia. The
negroes transport the gold in quills of the ostrich or vulture. These mines seem to
have been known to the ancients, who considered Ethiopia to abound in gold. Hero-
dotus relates that the king of that country exhibited to the ambassadors of Cambyses
all their prisoners bound with golden chains.
The second and chief exploitation of gold dust is to the south of the great desert of
Zaara, in the western part of Africa, from the mouth of the Senegal to the Cape of
Palms. The gold occurs in spangles, chiefly near the surface of the earth, in the beds
of rivulets, and always in a ferruginous earth. In some places the negroes dig pits
in the soil to a depth of about 40 feet, unsupported by any props: they do not follow
any vein ; nor do they construct a gallery; but by repeated washings they separate the
gold from the earthy matters.
The same district furnishes also the greater part of what is carried to Morocco, Fez,
and Algiers, by the caravans which go from Timbuctoo on the Niger, across the great
desert of Zaara. The gold which arrives by Sennaar at Cairo and Alexandria comes
from the same quarter. From Mungo Park's description, it appears that the gold
spangles are found usually in a ferruginous small gravel, 4)uried under rolled pebbles.
The third spot in Africa where gold is collected is on the south-east coast, between
the twenty-fifth and the twenty-second degree of south latitude, opposite to Mada-
gascar, in the country of Sofala. Some persons think that this was the kingdom of
Ophir, whence Solomon obtained his gold.
During the last, and the commencement of the present century, the richest gold
mines were found in South America. It occurs there principally in spangles among
the alluvial earths, and in the beds of rivers ; more rarely in veins.
The gold of Mexico is in a great measure contained in the argentiferous veins, so
numerous in that country, whose principal localities are mentioned under the article
Silver. The silver of the argentiferous ores of Guanaxuato contains one 360th of its
weight of gold ; the annual product of the mines being valued at from 2640 to 3300
pounds avoirdupois.
Oaxaco contains the only auriferous veins explored as gold mines in Mexico ; they
traverse the rocks of gneiss and mica slate.
All the rivers of the province of Caracas, to ten degrees north of the line, flow over
golden sands.
Peru IS not rich in gold ores. In the provinces of Husulas and Pataz, this metal is
mined in veins of greasy quartz, variegated with red ferruginous spots, which traverse
primitive rocks. The mines called pcKos de orOf consist of ores of iron and copper
oxides, containing a great quantity of gold.
Vol. IL C C
386 GOLD-
All the gold farnished hj Kew Grenada (New Columbia) is the product of wash*
ings established in allavial grounds. The gold. exists in spangles tLoA in grains, dis-
seminated among fragments of greenstone and porphyry. At Cboco, along with the
gold and platinum, hyacinths, zireons, and titanium occur. There has been found, as
already stated, in the auriferous localities, large trunks of petrified trees. The gold
of Antioquia is 20 carats fine, that of Choco 21, and the largest li:unp or pepita of gold
-weighed about 27^ pounds avoirdupois. The gold of Chili also occurs in allayial
formations.
Brazil does not contain any gold mine, properly so called ; for the reins containing
the metal are seldom worked. Dr. Walsh says gold was first known to exist in the
Brazils in 1 543. The Indians made their fishing-hooks of it, and from them it was
discovered that it was found in the beds of streams, brought down from the mountains.
But the first ore found by a white man in that country was in the year 1693 ; this
discovery led to the colonisation of the Minas Geraes, and to all those evils resulting
from ** the cursed lust of gold," with details of which the history of South America
abounds.
It is in the sands of the Mandi, a branch of the Rio-Dolce, at Catapreta, that the
auriferous ferruginous sands were first discovered in 1683. Since then they have
been found almost everywhere at the foot of the immense chun of mountains, which
runs nearly parallel with the coast, from the 5th degree south to the SOth. It is par*
ticularly near Villa Rica, in the environs of the village Cocaes, that the nomeroos
washings for gold are established. The pepitcu occur in different forms, often adhering
to micaceous specular iron. But in the province of Minas Geriies, the gold oeenrs
also in veins, in beds, and in grains, dissemmated among the alluvial loams. It has
been estimated in annual product, by several authors, at about 2800 pounds avoir-
dupois of fine metal
We thus see that almost all the gold brought into the market has come from alla-
vial lands, and has been extracted by washing.
Calif omian Gold Mines. — The accident which first revealed the golden treasures
of the soil of California, is thus related by a writer in the Quarterly Review, fbr Sep-
tember, 1852. Captain Suter, the first white man who had established himself in the
district where the Americanos Joins the Sacramento, having erected a saw-mill on the
former river, whose tail race turned out to be too narrow, took out the wheel, and let
the water run freely off. A great body of earth having been carried away by the
torrent, laid bare many shining yellow spangles, and on examination Mr. Marshall,
his surveyor, picked up several little lumps of gold. He and Captain Suter then
commenced a search together, and gathered an ounce of the ore from the sand without
any difficulty ; and with his knife the captain picked out a lump of an ounce and a
half from the rock. A Kentuckian workman employed at the mill had espied their
supposed secret discovery, and when after a short absence the gentlemen returned, he
showed them a handful of the glittering dust The captain hired a gang of fifty
Indians, and set them to work. The news spread, but the announcement of the dis-
covery was received with incredulity beyond the immediate neighbourhood. But
presently when large and continuous imports of gold fh)m San Francisco placed the
matter beyond doubt, there ensued such a stir in the States, as even in that go-ahead
region is wholly without parallel : numbers of every age and of every variety of
occupation pushed for the land of promise. Many were accompanied by their families.
and most under the excitement of the hour overlooked their physical unfitness, and
their inability to procure necessaries. The waters of the Humboldt, fVom their head
to their " sink," a space of nearly 300 miles, are in the dry season strongly impreg-
nated with alkali : and it was here that they first began to fiunt Some died tro/ok uirst,
others from ague, others fell beneath the burdens they attempted to carry when their
last animal dropped into the putrid marsh, which grew thicker at every step. Beyond
the ** sink " the diminished bands had to encounter sixty or seventy miles of desert,
where not a blade of herbage grew, and not a drop of pure water coidd be procured ;
and those who pushed safely through this ordeal had still to ascend the icy slopes of
Sierra Nevada, when the rigours of winter were added to all other difficulties. At
different points, one being almost in sight of the golden land, overwearied groups had
formed encampments, in case perhaps some help might reach them. It w to the
eredit of the settlers that on hearing this, they strained their resources to the utmost
to afford relief. Yet when all was done, a sick, destitute, most wretched horde of
stragglers, was all that remained of the multitude, who, fhll of hope and spirits, had
commenced the prairie journey.
It may be advantageous in this place to determine the difference between the
amounts of gold passing into the European markets, before the discoveries of the gold
fields of California, and especially of those of Anstrnlia, io contrast with the total
produce of these countries at the present time.
60LIX
887
Table of the quantiiie$ of GM which may be considered aa having been brought imto
the European market, every year on an average^ from 1790 to 1802.
Codtinentt.
Gold.
ANcisirr Continent.
Asia : — Siberia -----•.-
Africa - - - -•- - -.-
Europe: — Hungary- -
Salzbourg - -
Austrian States, Hartz and Hessia, Sazooy, Nor-
way, Sweden, France, Spain, &c. •>
Total of the Ancient Continent - - - ^ - .
Nsw Continent.
North America ---------
South America : — Spanish dominions . . - .
Brazil - - - - • - -
Total of the New Continent
lbs. Avoir.
8740
3300
1430
165
165
8800.
2,860
22,000
15,400
40,260
The mines of America haye sent into Europe three and a half times more gold, and
twelve times more sjlrer, than. those of the ancient continent The total quantity of
siWer was to that of gold in the ratio of 55 to 1 ; a very different ratio from that which
holds really in the value of these two metals, which is in Europe as 1 to 15. This
difference depends upon several causes, which cannot be investigated here at length ;
but it may be stated, that gold, by its rarity and price, being much less employed in
the arts than silver, the demand ror it is also much less ; and this cause is sufficient
to lower its price much beneath what it would have been, ff it had followed the ratio
of its quantity compared to that of silver. Thus also bismuth, tin, &c., though much
rarer than silver, are, nevertheless, very inferior in price to it. Before the discovery
of America, the value of gold was not so distant from that of silver, because since that
era silver has been distributed in Europe in a far greater proportion than gold. In
Asia the proportion is now actually only 1 to II or 12 ; the product of the gold mines
in that quarter, being not so much below that of the silver mines as in the rest of the
world.
The total annual production of gold, exclusive of CaUfomia and Australia, at pre-
sent, has been estimated as follows :
From the ancient Spanish colonies of America - - 10,400 kilogrammes
Brasil 600
Europe and Asiatic Russia - - - - . - 6,200
The Indian Archipelago ----- 4,700
Africa 14,000?
85,900 -• 36 tons nearly,
without taking into account the quantity of gold now extracted from silver.
Report of the production of Gold since its discovery m California^
in
£
in
£
1848
•
-
11,700
1853
*
- 12,500,000
1849
-
-
1,600,000
1854
a
- 14,100,000
1850
—
m
5,000,000
1855
•
- 13,400,000
1851
-
-
8,250,000
18fi&
—
- 14,000,000
1852
- '
-
11,700,000
1867
—
- 13,110,000
The history of the jpltoduction of gold in California and the States of the Union, is
well told in the following table, showinff the deposits of gold in the limits of the
United States. These have been supphed for this work by the obliging kindness of
Mr. Rockwell, of Washington.
cc 2
888
GOLD.
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GOLD.
889
"S* Branch Mint, San Francisco.
Pniod*
CBlifornia.
Total.
1854 ....
1855 . . . -
1856 . - . -
1857 to June 30 .
Total
Dollars.
10,842,281*23
20,860,427-20
29,209,218-24
12,526,826-93
Dollars.
10,842,281-23
20,860,427-20
29,209,218*24
12,526,826-93
73,438,763-60
73,438,763-60
3. Branch Mint, New Orleans.
IS3a-47
1848
1849
ISfiO
1851
1858
I8&3
18M
1865
1856
1857 to
Jane 80
Total
North
GaioUiuu
Doliara.
741
I
741
Booth
OuoUna.
Dollars.
14,306
1,488
16,317
Qoorgia.
Dollars.
87,364
M17
>,681
Alshama.
Dollars.
61,908
6,717
4,069
8.560
1,040
77,183
Osllinmia.
TsnacBsee.
Other
Sourocs.
Dollars.
Dollars.
Dollars.
•
1,778
8,618
1,184
947
.
668.981
8,788
4,575,576
884
8,768,683
.
8,7n,784
-
8,006.678
> .
981.511
.
411,517-84
. m
SS8,844-91
-
190,888*a9
-
81.606,461*64
8,719
7,290
Total.
Dollars.
119,699
18.593
677,189
4,580,090
8,770,783
8,777,784
8.006,678
981,511
411.617-94
883,344-91
139,828-89
81,750,891*64
4. Branch Mint» Charlotte, North Carolina.
Period.
North Carolina.
Sooth Carolina.
CaUforaia.
TotaL
1838 to 1847
1848 .
1849 .
1850 .
1851 .
1853 .
1853 .
1854 .
1855 .
1856 .
1857 to Jane
30 !
. DolUrs.
1,529,777
359,075
378,223
307,289
275,472
337,604
227,847
188,277
196,89403
157,355*18
75,696*47
Dollars.
143,941
11,710
12,509
13,000
25,478
64,934
61,845
19,001
14,27717
Dollars.
15,111
28,362
15,465
6,328
5,817-66
15,237-35
Dollars.
1,673,718
370,785
890,732
320,289
316,061
430,900
305,157
213,606
216,988-86
173,592-53
75,376*47
Total .
4,033,189-68
366,695*17
87,321*01
4,487,205*86
5. Branch Mint, Dahionega, Oeor^
Ptoiod.
North
Osrolina.
Soath
Carolina.
Oeoftfa.
Tnncssee.
AlsTMnTTAi
CUlftunla.
Other
Sonroes.
TotaL
Dollars.
Dollars.
Dollars.
Dollars.
Dollars.
ttoilars.
Dollars.
Dollars.
1838-47
64^1
95.497
2378.853
82.175
47.711
■ «
.
3.218.017
1848
5,434
8,151
851,376
8,717
4,075
m m
.
971.753
1849
4.888
7,328
225,894
2,441
8,661
• •
.
944.131
1M50
4,500
6,700
804,478
1.200
1,800
80,026
•
947,698
1851
1.971
8,236
154.783
8,251
9,106
214,079
951
879.309
la'is
448
67.643
93,128
760
• .
824,931
. •
476,789
1853
8.086
33.950
66384
149
.
809,122
m «
452.290
J 854
5318
16.988
47,087;
938
.
211,169
.
980.985
1855
8,146*88
9,113-87
66.686-36
m •
877-92
47.428-70
«B «»
116.659-07
1856
-
86,728-76
44,107*99
106*49
m m
81,467-10
m m
101,405*96
1857 to
June 80
1- -
8,063*89
85,097*63
4,187,773*98
■• w
« m
6.498-62
-
89.679-64
Total
93.639*88
870,388-91
49/112-42
59.629-99
1,28«,719>89
961
6,837,948*87
CC 3
390
GOLD*
6. Aauj Office, New York.
Period.
Ylcginia.
North
OaroUna.
Booth
Carolina.
Geoisia.
Alabama.
T^Bn-
ncisee.
CaUftnia.
Other
Sooroes.
TWaL
1M4
1855
IHA6
1857 to
June 30
Dollars.
167
2,370
1,928
} 1.531
Dollars.
3.916
8,750
805-07
1,689
Dollars.
395
7,620
4,052-29
2.668
Dollars.
1.242
13,100
41,101-28
10.451
Dollars.
"sso"
833'68
1,545
Dollars.
Dollars.
9.221,457
85,025.H9$-11
16.629.008*90
9,899.957
Dollars.
16Q0'
" DolUri.
9,W7,177
16,S8a.l»-l<
9.917336
Total
10.996
10,160*07
14.730-29
65.894-28
2.128-62
- -
60,676.3I9-01
1600
G0.78],8S8-»
Summary exhibit of the entire Deposite of Domestic Gold at the United States MintoMd
Branches from 1804 to the SOth June 1857.
Virginia - -
North Ca olina
Soath Carolina
Georgia .
Tennessee
Alabama -
New Mexico -
California
Other Sources
Total -
MinU
FhHadelphia.
Dollars.
l,479,7R5-6C
4j400.373
ft35.492
2.874.793-50
35,56*1
51.944
49.897
2a6.839.fi2r62J73»438J63-60
95,740
235,864.614*62
San Fran-
cisco.
If ev Orleans.
Dollars.
Dollars. ~
741
16.217
8,968
2,719
77,282
21.606,461-54
7,290
Chailotte.
Dollars.
4,033.189-68
866,695-17
87«32101
73,4S8,768>60 21,7(0,891-64
4,487.905-8<,
Dahlonega.
DoUara.
92,629-82
270.2S8-91
4,187,773-9«
42,01 a'4'2
60,629-9
1,224,713*82
951*
S,R97,94B'87
Offlos.
Dollars.
10,996
10,160-07
U,730-29
65,894*28
' 2.1M-62
60.676,319-01
1,600
Total
DolUn.
I,49a78l»
8,537.0»S^
l.SQM73^3r
6,618,l4t';C
4«iB7
88S^,(»ai
105.»1
60,78l,828-27| 40S,1SOJM^
Exports of gold and silver bullion from the United States, as shoirn by the aoooal
official reports on ** Commerce and Navigation," bj the Secretary of the Treasury of
the United States. (Prior to 1865, the reports do not show separately the coin from
ihelntUion, and in the following years silver is not separated fr<»a gold^ but almost tb«
entire amount was undoubtedly gold.)
Dollars. Dollars.
1855 - - 34,114,995
1856 - - 28,689,946, of which from S. Francisco, 6,947,404
1867 - - 31,300,980 „ 9,922,257
The gold, the production of foreign countries, imported into the United States for
the years ending 30th Jnne, was as follows : —
Ywur.
1852
1853
1854
1855
1856
1857
BuUioa.
$608,257
463,044
1,720,711
404,217
114,289
151,585
Coin.
03,049.802
1,962.312
1,311,253
688,585
876,046
6,503,051
Shipments of gold from San Francisco colony, to eastern domestic parts and foreiga
ports, from the San Francisco Price Current: —
1853
1854
United States.
947.916,447*1,
46,289,649^1,
England.
»4,975,662#<,
3,781,080*1,
Other Countries.
01,913,990.73
1,163,779,78
Total in 1853
1854
»»
054,906.100^
351,234,.508/a
Australian Gold Mines.-^The discOYcry of the great gold field in Australia to the
westward of Bathurst, about 150 miles fi-om Sydney, was officially miide known lo
GOLD. 391
GrMt BriUin, t^ a de*pntch from Sir C A. Fitiroj to Esri Grey, on ibe IStli S«p>
Mmtwr, I8SI, many peraona with a tin dijh bating obuiopd fVom one to tvo oances per
da J. On the 3St)i « Hay, he write* tlial lumpa bare bees obtained varying in weight
frmn one onnce to foar poanda OnIhe29Ib of MaT.be write* that gold hu been found
in abandonee, tbat people of erery chw are proceeding to the locBiitj, that the fieid i*
rieb, and Irma the geological formation of the coontry, of immeTiae area. By way
the gold ii foDodu conaiat of 9l'l of tbat metal and about 8 '333 of ai Iter, vilh a little
baw metal i orofSS cant* inflDeoeti. July 17ib. a msasof goldweigbing 106 pooadi
-wu tbnnd imbedded in the qnartz matrix, aboot 53 milea from BatharH ; and mucb
more, Joatifying the anlicipatioos formed of the Tiit richneas and extent of the gold
field in thia colony, Thia magnificent (reasarc. tbe properly of Dr. Kerr, lurpaMed
the large*! matt found in Califomia, vhicb va> 2B poondi ; and that in Rnaaia, which
«*a 70 ponnda, now in Ibe museum at Si. Peterabnrg. One party of >ix peraons gol
M the lame dme iOOL in ten daja bj meana of a quickitlTer machine ; and a parly ol
three, who were anaucceufiil for leven days, oblained in five dayi more tban 2U0
ouncei. A royalty of 10 per cent, waa ordered to be paid on gold in matrix if found
in Crown lani^, and 5 per cent, if foond in private property.
KamerouB claima have been made by persona who have thought that tbey bad
given the firat indications of gold in Anstralia. To Sir Koderick Murchison is, how-
ever, doe tbe merit of pointing oat that gold might probably be (band in Australia
long befure it waa known in Eorope that gold existed in that important colony. Sii
Roderick Murchiaon thus gives us tbe facia : — " Having in the year 1844 recently
mnrned ftxim tbe auriferous Ural mounuina, I bad the advantage of examining thci
niuneroaa specimens collected by my friend Count Strielecki along the eaatem chain
of Anatralia. Seeing tbe great similarity of the rocks of those two distant countriea,
1 could have little difficulty in drawing a parallel between them ; in doing wbieb I
WBi natondly struck by tba elrcomatance that no gold bad i/el been found in tbe
Anstralian range, which 1 termed in anticipation the 'Cordillera,' impressed with
tbe conviction that gold would, aoouer or later, be found in the great British Colony.
I learnt in lS4e with aatishction Ihst a apecimen of the ore had been discovered. I
tbereopon enconraged tbe unemployed miners of Cornwall to emigrate, and dig fbr
gold as tbejdugfor tin in the gravel of their own district. These notices were, as far
at I know, the first printed documents relating to Australian gold."
Augoat 39th, 185 LLieatensat-Govemor C.J. I.atrobe announced to Earl Orej fi'Om
Melbourne, the discovery of large deposits of gold in that dittrict of tbe colony. In a
second Parliamentary bine book, issued February 3, 1852, it is stated that 79.340 ounces
of gold, worth 257,855^. 7>., had been previously forwarded to England; and that the gold
fields ofthe colony of Victoria rival, if they do not exceed in value, the first discovered
gold fields of New South Wales ; tbe total value being then 300,000[. ; and but a little
time aAerwirda about half a million sterling. Mr. E. Hargraves. commissioner fot
Crown land*, annonuced fiDm Balbunf, that no part of California which he had seen
baa prodaced gold so generally and to such an extent as Summerhill Creek, tbe Turon
River, and its tributaries.
For tbe purpose of conveying a correct idea of the conditions under wliich the
greatMt quantity of the Anstralian gold oceans, three plans hove been selected from
different districts. Tbe first of these (,fig. 920) represents a longitudinal section
alimg the course of the west qimrti rein in the Clunea gold-mining field. We bave
here, as indicated by tbe darker portions of Ibe wood-cut, the quarts vein shown in
section, with the shi^ sunk, and the levels driven upon it. The lighter porlioua ol
the figure resting on the quartioae rock is an anriferuus drift ; and on tbe left of the
section the great basaltic formation is shown.
Fig. 921 iaa aection of a portion of the Bollarat gold-fiifld. It is an east and west
section from the Red Streftk-Iead across Post office Ilil), White Flat, the township of
In those two aectionB we bare, therefore, all the conditioDl shown of the p
of miDing on the qoani lodes and in the aUnviai depoiiu.
Fig. 923 il a lection fhna tb<
Boroondsn and Bulleen gold
P minea, a few milei &om tbe ea-
/ pilal of Victoria It U the eut
' and west section of the Carltoa
4 Estate qoarti ree^ and is mmiiilr
/ given to illnslrate the nnakilfiil
/, and dangerous cotiditioD of manf
y of the workings nndenaken hf
^ men who hare no experiCDce in
/ sobterrancan operations. Tbe
'/ shaft, if such it con be called, is
', about 40 feet deep ; and the reef
', dips with the solid strata at an
■, angle of abont 80 degrees to the
.' horiion.
'/ The wall of the shaft at a is
' not BQpported on the footwall bj
props and proper timbering,
which it ihonid be, as iadicxed
^ K B e. The windlsss at c and the frame-work at o are both ezceediaglj insecure.
This U the mode of proeeedinE in a very important working, where almost ereij
piece of qnaru broken odI contaiDS gold, and also antimony and iron. At tbe point t
the quartz reef was exceediDgljr rich, and there it branches off into small strings,
yielding 22 oanccs of gold to the ton.
Il is not nepeisarj- here to trace the prognta of gold-mining in this colony. The
quantity of gold discovered and enporled has been enormona. Some eiceedinglj
large "nuggets" have been foundi one in Forest Creek, weighing S7 lb*. 6 ot. 15dwta.
and the AVeleome Nugget, weighing S217 ox. 16 dwts.
The produce of the gold fields of Victoria in 1856 was as follows : —
The quantities brought to Melhoame and Geelong by escort, oi.
From Caitlemnin and onl-stations - ' - • - 372,897
„ Sandhorst and do. .... 599,100
„ Maryborongb and do. .... 327,709
„ Ballaratand do. .... i,oos,S23
„ Beechworth and do. .... 334,709
2,644,237
Brou^t by privale hand . . . . , 824,323
Quantity which has eraded duly .... 59,411
Id the treainry banka at camp, dec, and in transitu - 419.190
Total - - - 3.947,160 oi.
GOLD.
893
The exports of gold from Australia nneo 1651 haye been aa follows : —
Valae.
■
ValuA.
£
£
1851
.
907,113
1855
' 11,518,230
1852
-
- 9,735»903
1856
- 12,740.480
1853
-
- 10.445,700
1857
- 11,764,299
1854
-
- 9,028,759
The qnantities of gold exported from Kew South Wales alone in the same periods
have been : —
QuantltiM.
ValiM.
ost. dirta. gn.
< : A
1851
144,120 17 16
468,336 0 0
1852
818,751 18 17
2,660,946 0 0
1853 . - .
548,052 19 21
1,781,172 0 0
1854 ...
237,910 13 23
773,209 0 0
1855 ...
64,384 14 3
209,250 0 0
1856
42,463 17 1
138,006 0 0
1857 to 3l8t March .
17,088 8 0
64,081 10 0
1,872,773 9 9
6,095,000 10 0
The remainder being the prodnce of the gold fields of Victoria.
Gold has been discovered in some considerable quantities in Tasmania. It has been
reported as having been fonnd, although as yet not to any great extent, in New Zealand ;
and it is well known that this precious metal is found in all the islands of the eastern
Archipelago.
The recent dieeooeriea of Gold in British Columbia, — The following communication
fh>m a correspondent to the Victoria Gazette^ Vancouver's IsUmd, is especially
interesting. It is dated Upper Fraser JRiver^ Nov. 28, 1858.
Magnitude of the Gold-fields of British Columbia, — ** That the auriferous deposits of
this region are spread over a considerable scope of country is apparent from the fiict
that paying diggings have already been found on the Fraser River, extendiugfrom Fort
Hope almost to Fort Alexander, a continuous distance of nearly 400 miles. Among the
tributaries of this stream, Thompson and Bridge rivers are known to be auriferous —
the latter sufficiently so to have already richly rewarded those who have laboured upon
it as high up as 35 or 40 miles from its mouth, while the former has been ascertained
to have many bars that will pay in its bed. On two of its confluents — Nicholas and
Bonaparte Rivers— good diggings are reported to have been recently discovered. How
many more of the numerous branches of these streams shall yet be found abounding
in gold remains to be seen, little or no prospecting having thus far been done upon
them. Nor is the extent of this gold-field likely to be limit^ to these rivers and their
sources. Coarse gold was fonnd about six weeks since by some packers while ex-
ploring for a mule route around Lake Seton. It was discovered on a large creek flow*
mg into the outlet of the lake at a point about 15 miles from the Fraser. The dust
was apparently of high standard value: at two places on the Lillooet River bars having
been found that will warrant working with a sluice. The first of these is on the east
side of the stream, 10 miles above Port Douglas, where a party are now washing widi
sluices with very satis&ctory results. When I passed the spot they had been at work
but two days ; the first day three men took out 014 50c, tiie next day, $Sl8. They
showed me the gold, which was fine, like that found on the Lower Fraser. The other
bar is 20 miles above Port Douglas. It is very extensive, and promises to pay as well
as the one first named, though it has not yet been worked. Bars similar to these are
abundant on the Lillooet, and the &ct of these having been prospected was owing to
the accident of a log cabin having been built near them, and not because they seemed
more likely to contain gold than the others, For 100 miles above the Favilion, and
beyond what is termed the Canoe Country, the banks of Fraser Biver have been proved
to pay even better than below, the gold being coarser and more easily saved, as well
as more plentiful. It will thus be seen that the gold-fields of British Columbia, ascer-
tained to be paying, to say nothing of rumoured discoveries beyond, are tolerably ex-
tensive. They do not, it is true, rival those of California or Australia in magnitude;
but that they cover a large scope of country, and will give employment to a large
population, is settled beyond controversy or question."
Biehness of the Mines,— ^ To claim that the Fraser River mines are as rich, or that
394 GOLD BEATING.
labour has been generally as irell rewarded in them as in the mines of California at an
early day, would be idle. I might say much in explanation of the numerous failures that
attended the first adventurers to these mines, without making myself their apologist —
how the miners came too soon and in too great numbers — how the river kept up, and
of the many disadvantages under which they laboured ; all might be enlarged upon
were it not now well known to the public. In regard to this section, however, I may
say those pioneers who worked here last winter and spring uniformly made lai^
wages; and that those who came in since have been able to remain, paying the enormous
prices they have done for provisions, proves that they must have had good paying
claims most of the time. The cost of living here, with other necessary expenditures^
could not have been less than 34 a day to the man, yet I find all have been able to
defray their current expenses, while many have accumulated large sums — sufilciently
large in a majority of cases, with those who have been here any length of time, to lay
in a winter's stock of provisions, even at the present high prices. That better average
wages can be made here than in any part of California at present there is no doubt
This can be done even with the present want of ditches and indifferent appliances for
taking out the gold. These diggings, owing to the fineness of the dust and the difficulty
of saving it, require to be worked with sluices — a mode that has been introduced to
but a limited extent as yet, owing to the want of lumber, as well as of wheels or ditches
for supplying water. When sluices shall have been generally brought into use, more
than twice the amount now realised can be taken out to hand. Another cause that
will tend to render these mines highly remunerative in the aggregate is, that every
man will be able to secure a claim, and that but little capital will be required for start-
ing operations; hence every one will enjoy the full fruits of his own labour, and none
need remain idle. For this winter, owing to the lateness with which provisions hare
been got in, not much will be done ; no one here expects it ; the utmost that will be
aimed at, as a general thing, will be to make enough to pay expenses of living, to
prospect a little, and be on hand at the breaking up of winter. AVith the coming of
spring large operations will be entered into, and all here entertain the most sanguine
anticipations, or rather, I should say, fullest confidence as to the results."
Their durability. — " That these mines will be found not only rich and extensive,
but also lasting, I am fully satisfied. Apart from their vast extent of surfiace, the
d'g^nS<i &t one time thought to be shallow, are now known to run downward in many
localities to a good depth. It has lately been ascertained that not only the bars along
the river, but many of the lower benches or table lands contain sufficient gold to pay
where water can be brought upon them, which in most cases can easily be done.
These benches are not only numerous, but often of great extent, and would afford
employment for a large number of men for many years to come. Little or no search
has been made as yet for drift diggings or quartz, though there are abundant indications
that both, of a paying character, exist Fine ledges of quartz, in fact present themselves
almost everywhere, though no thorough examination has been made of their quality.
The banks of Bridge River consist of alternate strata of slate and quartz rock, the most
favourable possible geological formation for gold. I would venture, then, after having
seen considerable of the mines in this quarter, to express the confident opinion thai
they will pfove sufficiently extensive, productive, and lasting to warrant a large im-
migration to this country in the ensuing season, and that British Columbia is destined
to become^ another great gold -producing region, ranking next to California and
Australia in the amount she will hereafter annually yield of this precious com-
modity."
Such is a general view of the gold producing districts of the world. Much fear
has been expressed least the influx of gold should reduce the value of that metaL
Since the discovery of the Californian gold-field in 1648, not less than £1 59,807,184
sterling has been added to the wealth of Europe and America from the great gold'
fields of California and Australia. This question cannot be discussed in this place,
but it is one of the greatest interest, demanding alike the consideration of the politician
and the social philosopher.
GOLD BEATING. This is the art of reducing gold to extremely thin leaves, by
beating with a hanuner. The processes employed for this purpose may be applied t(»
other metals, as silver, phitinum, and copper. The Romans used to gild Uie ceilings and
wails of their apartments ; and Pliny tells us, that from an ounce of gold forming a
plate of 4 fingers square, about 600 leaves of the same area were hammered. At the
present day, a piece of gold is extended so as to cover a space 651,590 times greater
than its primary surface when cast
The gold employed in this art ought to be of the finest standard. Alloy hardens
gold and renders it less malleable ; so that the fraudulent tradesman who should attempt
to debase the gold, would expose himself to much greater loss in the operations, than
he could derive of profit from the alloy.
GOLD BEATING. 395
. Foor principal operations eonstitate the art of gM beating:—
1. The casting of the gold ingots. 3. The lamination.
3. The hammering. 4. The beating.
1. The gold is melted in a oraoible along with a little borax. When it has become
liquid enoagh, it is poured out into an ingot-mould previouslj heated, and greased on
the inside. The ingot is taken out and annealed in hot ashes, which both soften it and
free it from grease. The moulds are made of cast-iron, with a somewhat concaTc in-
ternal surface, to compensate for the greater contraction of the central parts of the metal
in cooling than the edges. The ingots weigh about 2 ounces each, and are } of ao
inch broad.
2. TTie/ort/ing. — ^When the ingot is cold, the French gold-beaters hammer it out on
a mass of steel 4 inches long and 3 broad. The hammer for this purpose is called the
forging hammer. It weighs about 3 pounds, with a head at one end and a wedge at the
other, the head presenting a square face of 1^ inch. Its handle is 6 inches long. The
workman reduces the ingot to the thickness of } of an inch at most ; and during this
operation he anneals it whenever its substance becomes hard and apt to crack. The
English gold-beaters omit this process of hammering.
3. T7ie lamination,~^The rollers employed for this purpose should be of a most per-
fectly cylindrical figure, a polished siurfaoe, and so powerful as not to bend or yield in
the operation. The ultimate excellence of the gold leaf depends very much on the pre«
cision with which the riband is extended in the rolling press. The gold-beater desires
to have a riband of such thinness that a square inch of it will weigh 6^ grains. Fre-
quent annealings are requisite during the lamination.
4. Beating, — The riband of gold being thus prepared uniform, the gold-beater cuts
it with shears into small squares of an inch each, having previously divided it with
compasses, so that the pieces may be of as equal weight as possible. The squares
are piled over each other in parcels of 150, with a piece of fine calf-skin vellum
interposed between each, and about 20 extra vellums at the top and bottom. These
vellum leaves are about 4 inches square, on whose centre lie the gold laminsD of an
inch square. This packet is kept together by being thrust into a case of strong
parchment open at the ends, so as to form a belt or band, whose open sides are
covered in by a second case drawn over the packet at right angles to the first. Thus
the packet becomes sufficiently compact to bear beating with a hammer of 15 or 16
pounds weight, having a circular face nearly 4 inches diameter, and somewhat convex,
whereby it strikes the centre of the packet most forcibly, and thus sqneexes out the
plates laterally.
The beating is performed on a very strong bench or stool, framed to receive a heavy
block of marble, about 9 inches square on the surface, enclosed upon every side by
wood-work, except the front, where a leather apron is attached which the workman lays
before him to preserve any fragments of gold that may &11 out of the packet. The
hammer is short-handled, and is managed by the workman with one hand; who strikes
fairly on the middle of the packet, frequently turning it over to beat both sides alike ;
a feat dextronsly done in the interval of two strokes, so as not to lose a blow. The
packet is occasionally bent or rolled between the hands, to loosen the leaves and secure
the ready extension of the gold ; or it is taken to pieces to examine the gold, and to
shift &e central leaves to the outside, and vice versei, that everything may be equalised.
Whenever the gold plates have extended under this treatment to nearly the size of the
vellum, they are removed from the packet, and cut into four equal squares by a knife.
They are thus reduced to nearly the same size as at first, and are again made np into
packets and enclosed as before, with this difference, that skins prepared from ox-gut
are now interposed between each gold leaf^ instead of vellum^ The second course of
beating is performed with a smaller hammer, about 10 pounds in weight, and is con*
tinued till the leaves are extended to the sixe of the skins. During this period, the
packet must be often folded, to render the gold as loose as possible between the mem-
branes ; otherwise the leaves are easily chafed and broken. They are once more
spread on a cushion, and subdivided into four square pieces by means of two pieces of
eane cut to very sharp edges, and fixed down transversely on a board. This rectan-
gular cross being applied on each leaf, with slight pressure, divides it into four eqiud
portions. These are next made up into a third packet of convenient thickness, and
finally hammered out to the area of fine gold leaf, whose average size is from 3 to 3^
inches square. The leaves will now have obtained an area 192 times greater than the
plates before the hammering begun. As these were originally an inch square, and 75
of them weighed an ounce ( s 6^ x 75 « 487^), the surfiice of the finished leaves
will be 192 x 75 » 14,400 square inches, or 100 square feet per ounce troy. This
is by no means the ultimate degree of attenuation, for an ounce may be hammered
so as to cover 1 60 square feet ; but the waste incident in this case, from the number
of broken leaves, and the increase and nicety of the labour, make this an unprofitable
396 GOLD, METALLURGIC TREATMENT OF.
refinement ; wliile the gilder finds such thin leaves to make less durable and atis-
factory work.
The finished leaves of gold are put np in small books made of single leaves of soft
paper, nibbed over with i^ed chalk to prevent adhesion between them. Before putting
the leaves in these books, however, they are lifted one by one with a delicate pair of pin«
cers out of the finishing packet, and spread out on a leather cushion by blowing them
flat down. They are then cut to one size, by a sharp-edged square moulding of cane*
glued on a fiat board. When this square>framed edge is pressed upon the gold, it cols
it to the desired size and shape. Each book commonly contains 25 gold leaves.
We must now describe some peculiarities of the French practice of gold beating. The
workman cuts the laminated ribands of an inch broad into portions an inch and a half
long. These are called quartiera. He takes 24 of them, which he places exactly over
each other, so as to form a thickness of about an inch, the riband being ^ of a line, or
ji of an inch thick ; and he beats them together on a steel slab with the round fiue
i^panne) of the hammer, so as to stretch them truly out into the square form. He be-
gins by extending the substance towards the edges, thereafter advancing towards the
middle ; he then does as much on the other side, and finally hammers the centre. By
repeating this mode of beating as often as necessary, he reduces at once all the quartien
(squares) of the same packet, till none of them is thicker than a leaf of grey paper, and
of the size of a square of 2 inches each side.
When the qtiartiers are brought to this state, the workman takes 56 of them, which
he piles over each other, and with which he forms the first packet (caucher) in the
manner already described ; only two leaves of vellum are interposed between each gold
leaf. The empty leaves of vellum at the top and bottom of the packet are called
emplures. They are 4 inches square, as well as the parchment pieces.
The packet thus prepared forms a rectangular parallelepiped ; it is enclosed in two
sheathes, composed each of several leaves of parchment applied to each, and gloed al
the two sides, forming a bag open at either end.
The block of black marble is a foot square at top, and 18 inches deep, and is framed
as above described. The hammer used for beating the first packet is called the flat,
or the enlarging hammer ; its head is round, about 5 inches in diameter, and very
slightly convex. It is 6 inches high, and tapers gradually from its head to the other
extremity, which gives it the form of a hexagonid truncated pyramid. It weighs 14
or 15 pounds.
The French gold-beaters employ besides this hammer, three others of the same
form ; namely, 1. The commencing hammer y which weighs 6 or 7 pounds, has a head
4 inches in diameter, and is more convex than the former. 2. The spreading hammer^
(marteau a chasser) ; its head is two inches diameter, more convex than the last, and
weighs only 4 or 5 pounds. 3. The finishing hammer; it weighs 12 or 13 pounds, has
a head four inches diameter, and is the most convex of alL
The beating processes do not differ essentially from the English described above.
The vellum is rubbed over with fine calcined Paris plaster, with a hare's foot The
skin of the gold-beater is a pellicle separated from the outer surface of ox-gut ; but
before being employed for this purpose, it must undergo two preparations. 1. It
is sweated, m order to expel any grease it may contain. With this view, each piece
of membrane is placed between two leaves of white paper ; several of these pairs are
piled over each other, and struck strongly with a hammer, which drives the grease
from the gut into the paper.
2. A body is given to the pieces of gut ; that is, they are moistened with an infusion
of cinnamon, nutmeg, and other warm and aromatic ingredients, in order to preserve
them ; an operation repeated after they have been dried in the air. When the leaves
of skin are dry, they are put in a press, and are now ready for use. After the parch*
ment, vellum, and gut membrane have been a good deal hammered, they become unfit
for work, till thev are restored to proper flexibility, by being placed leaf by leal,
between leaves or white paper, moistened sometimes with vinegar, at others with
white wine. They are left in this predicament for 3 or 4 hours, under compression
of a plank loaded with weights. When they have imbibed the proper humidity, they
are put between leaves of parchment 12 inches square, and beat in that situation for
a whole day. They are then rubbed over with fine calcined gypsum, as the vellum
was originally. The gut-skin is apt to contract damp in standing, and is therefore
dried before being used.
The average thickness of common gold leaf is »JL« of an inch.
GOLD, METALLURGIC TREATMENT OPTThe gold found in the sands of
rivers, or in auriferous soils, needs not be subjected to any metallurgic process, pro-
perly speaking. The gold seekers separate it from the sands, by washing them first
upon inclined tables, sometimes covered with a cloth, and then by hand in wooden
bowls of a particular form. The methods of working vary in different localities*
GOLD, METALLURGIC TREATMENT OF. 397
The people called Bohemians, Gigans, or Tehinganes, who wash the auriferous sands
in Hangar J, employ a plank with 24 transyerse grooves cut in its surface. They
hold this plank m an inclined position, and put the sand to be washed in the first
groove ; they then throw water on it, when the gold mixed with a little sand collects
usually towards the lowest furrow. They remove this mixture into a flat wooden
basin, and by a peculiar sleight of hand separate the gold entirely from the sand.
The richest of the auriferous ores consist of the native gold quite visible, disseminated
in a gangue, but the veins are seldom continuous for any length. The other ores of
this district are auriferous metallic sulphides, such as sulphides of copper, silver,
arsenic, &C., and particularly iron.
The stony ores are first ground in the stamping mill, and then washed in hand-
basins, or on wooden tables.
The auriferous sulphides are much more common, but much poorer than the former
ores ; some contain only one 200,000th part of gold, and yet they may be worked with
advantage, when treated with skill and economy.
The gold of these ores is separated by two different processes ; namely, by fosion
and amalgamation.
The aimferous metallic sulphides are firat roasted ; then melted into mattes, which
are roasted anew ; next fused with lead, whence an auriferous lead is obtained, which
may be refined by the process of cupellation.
When the ^Id ores are very rich, they are melted directly with lead, without pre-
Hminary calcination or fusion. These processes are however little practised, because
they are less economical and certain than amalgamation, especially when the gold ores
are very poor.
If these ores consist of copper pyrites, and if their treatment has been pushed to the
point of obtaining auriferous rose copper, or even black copper includmg gold, the
greeious metal cannot be separated by the process of liquation, because the gold«
aving more affinity for copper than for lead, can be but partially run off by the latter
metaL For these reasons the process of amalgamation is far preferable. This process
being the same for silver, we reserve its full description for that metal. See Selveil <
The rich ores in which the native gold is apparent, and merely disseminated in a
stony gangue, are directly triturated with quicksilver, without any preparatory opera-
tion. As to the poor ores, in which the gold seems lost amid a great mass of iron,
sulphide of copper, &&, they are subjected to a roasting process before being amal-
gamated. This process seems requisite to lay bare the gold enveloped in the sulphurets.
The quicksilver with which the ore is now ground seizes the whole of its gold, in
however small quantity this metal may be present
The gold produced by the refining process with lead is free from copper and lead, but
it may contain iron, tin, or silver. It cannot be separated from iron and tin without
great difficulty and expense, if the proportion of gold be too small to admit of the em-
ployment of muriatic acid.
By cupellation with lead, gold may be deprived of any antimony united with it.
Tin gives gold a remarkable hardness and brittleness ; a piece of gold, exposed for
some time over a bath of red hot tin, becomes brittle. The same thing happens more
readily over antimony, from the volatility of this metal.| A two-thousandth part of
antimony, bismuth, or lead destroys the ductility of gold. The tin may be got rid of
by throwing some corrosive sublimate or nitre into a crucible, containing the melted
alloy. By the first agent, perchloride of tin is volatilised ; by the second, stannaie
of potash forms, which is carried off in the resulting alkaline scoriae.
Gold treated by the process of amalgamation contains commonly nothing but a little
silver. The silver is dissolved out by nitric acid, which leaves the gold untouched ;
but to make iii\s parting with success and economy on the great scale, several precautions
must be observed.
If the gold do not contain fully two-thirds of its weight of silver, this metal, being
thoroughly enveloped by the gold, is partially screened fh)m the action of the acid«
Whenever, therefore, it is known by a trial on a small scale, that the silver is much
below this proportion, we must bring the alloy of gold and silver to that standard by
adding the requisite quantity of the latter metal. This process is called quartation.
This alloy is then granulated or laminated ; and firom twice to thrice its weight of
sulphuric or nitric acid is to be boiled upon it ; and when it is judged that the solu-
tion has been pushed as far as possible by this first acid, it is decanted, and new acid
is poured on. Lastly, after having washed the gold, some sulphuric acid is to be boiled
over it, which carries off a two or three thousandth part of silver, which nitric acid
alone could not dissolve. Thus perfectly pure gold is obtained.
The silver held in solution by the sulphuric or nitric acid is precipitated in the me-
tallic state by copper, or in the state of chloride by sea- salt. See Assat, Metallurgt.
Gold has less affinity for oxygen than any other metal. When alone, it cannot be
398 GOLD THREAD.
oxidised by any degree of heat witli contact of air, althongli in combinatioa with otlier
oxidised bodies, it may pass In a state of an oxide, and be even vitnfied. The pur-
ple smoke into wbich gold leaf is oonrerted by an electric discharge is not an oxide,
for it is equally formed when the discharge is made through it in hydrogen gas. There
are two oxides of gold ; the first or protoxide is a green powder, wtuch may be ob-
tained by pouring, in the cold, a solution of potash into a solution of the metallic
chloride. It is not durable, but soon changes in the menstruum into metallic gold,
and peroxide. Its constituents are 96*13 metal, and 8*87 oxygen. The peroxide is
best prepared by adding magnesia to a solution of the metallic chloride ; washing the
precipitate with water till this no longer takes a yellow tint from muriatic acid ; then
digesting strong nitric acid upon the residuum, vhich removes the roagoesia, and leaves
the peroxide in the form of a black or dark brown powder, which seems to partake
more of the properties of a metallic acid than a base. It contains 10*77 per cent, of
oxygen. For the curious combination of gold and tin, called the Pdbfle Prbcipitatb
OF Cassius, see Cassius, Pigments.
Geld refining, — The following process has been patented as a foreign invention by
Mr. W. E. Newton in January, 1851.
It consists, 1, in reducing argentiferous or any other gold bullion to a granulated,
or spongy, or disintegrated molecular condition by fusion therewith of xinc, or some
other metal baser than silver, and the subsequent removal of the zinc by dilute snl-
phuric or other acid; that is, the reducing of the gold bullion to a state to allow of the
removal by acids of the silver and other impurities contained therein, so as to fit it
for coinage and other purposes without quartation with silver, or any other inter-
mediate process ; and 2, in pulverising, by grinding or concussion, gold bullion ren-
dered brittle by union with lead, solder, or other suitable metal, the silver and other
impurities being removed by acids in this as in the preceding case, and recovered from
the acid solution by any of the known chemical means. This operation, if properly
conducted, will produce fine ductile gold in a state of great purity ; that is, containing
from 98*5 to 99*5 per cent of pure gold.
GOLDBE ATER'S SKIN. This substance is the peritoneal or serous membrane,
separated from the intestinal tube of the ox, and sometimes from other animals ; it is
attenuated by being beaten with a hammer, and subsequently prepared so as to resist
putrefaction.
GOLD, MANNHEIM. A brass composed of from 8 to 4 oz. of zinc to one pound
of copper. See Brass.
GOLD, MOSAIC. A brass of very fine colour used in common Jewelleiy.
Hamilton and Parker's patent mosaic gold consists of 16^ ounces of zinc to 16 ounces
of copper. It is of a dark colour when first cast, but on dipping assumes a beautifiii
golden tint The patentees say, ** when cooled and broken idl ydlowness most cease,
and the tinge vary from reddish fawn or salmon colour, to a light purple or lilac, and
from that to whiteness. See .Brass Allots.
GOLD OF PLEASURE. A plant cultivated on the continent for iu seeds, which
yield a fine oil, while its fibres can be employed in the manufacture of sail-cloth,
packing, and other coarse articles. It is the Camelina sativa of botanists. It has not
attracted much attention in this country.
GOLD THREAD, or spun gojd^ is a flatted silver-gilt wire, wrapped or laid over a
thread of yellow silk, h^ twisting with a wheel or iron bobbins. By the aid of a
mechanism like the braiding machine, a number of threads may thus be twisted at once
by one master wheel. The principal nicety consists in so regulating the movements
that the successive volutions of the flatted wire on each thread may just touch one
another, and form a continuous covering. The French silver for gilding is said to be
alloyed with 5 or 6 pennyweights, and ours with 12 pennyweights of copper in the
pound troy. The gold is applied in leaves of greater or less thickness, acconling to the
quality of the gilt wire. The smallest proportion formerly allowed in this country by
act of parliament was 1 00 grains of gold to one pound, or 57 60 grains of silver ; but more
or less may now be used. The silver rod is encased in the gold leaf, and the compound
cylinder is then drawn into round wire down to a certain size, which is afterwards
flatted in a rolling mill, such as is described under Mint.
The liquor employed by goldsmiths to bring out a rich colour on the surface of
their trinkets, is made by dissolving 1 part of sea-salt, 1 part of alum, 2 parts of nitre,
in 3 or 4 of water. The pickle or sauce, as it is called, takes up not only the copper
alloy, but a notable quantity of gold ; the total amount of which in the Austrian
empire has been estimated annually at 47,000 francs. To recover this gold, the liquor
is diluted with at least twice its bulk of boiling water, and a solution of very pure green
sulphate of iron is poured into it The precipitate of gold is washed upon a filter,
dried, and purified by melting in a crucible along with a mixture of equal parts of nitre
and borax.
GRANITE. 399
GOLD WIRE, is formed bj drawing a cylindridal rod of the metal as pare as may
be, through a series of holes panched io an iron phite, diminishing progressi'vely in
size. The gold, as it is dravn throagh, becomes hardened by the operation, and re-
quires ft*eqaeot annealing.
GOLDE N M ARC ASITE. A name given at one time to the metal ainc. Albertos
Maimos calls it marchoMiia aurea, ** This was properly a stone, the metallic particles
of which were so entirely sublimated by fire, that nothing but useless ashes remained
behind. It contained fixed quicksilrer, communicated a colour to metals, on which
account it was well known to the alchemists, burned in the fire, and was at length en*
tirely consumed. It was found in Tarious parts, but that at Gaslar was the best, be*
cause the copper it contained seemed to have in it a mixture of gold. To give this
copper, however, a still greater resemblance to gold, some tin was added to it, by which
means it became more brittle. This marchasiUt also rendered copper white as silTcr.
Thus far Albertus. It obtained without doubt the name of marcfuuita aurea because
sine communicates a yellow colour to copper ; and for the same reason the Greeks
and the Arabians called Cadmia golden, or Aurea." — Beckmann,
GOLDEN SULPHURET OF ANTIMONY. Stibium Sulphuratum Auranticum.
The pentasulphide of antimony, a golden yellow powder, its formula being 8bS*.
See Antihont.
GONG-GONG, or iam-tam of the Chinese. A kind of cymbal made of a copper
alloy. See Coppbr.
GONIOMETE R. An instrument employed to measure the angles of crystals. The
most perfect instrument is the reflecting goniometer of Wollaston. The angle of the
crystal is measured by determining through what angular space the crystal must be
turned, so that two rays reflected fl'om two surfiices successiTcly shall have the same
direction. A simpler form of the instrument consists merely of a semicircular gradu-
ated scale of degrees with a movable and a fixed radius. It is a most important
instrument to the scientific mineralogist.
GOSSAN, a Cornish mining term. An oxide of iron, mixed with other matters.
Gossans are found on the upper portions of lodes, and according to their characters
are regarded by the miners as favourable or unfavourable indications. The gossans
are probably the result of the slow decomposition of the sulphate of iron from the
fluid in which the metalliferous matter, deposited in the lode, has been precipitated,
or of the sulphides which may have been previously fnrmed. The gossans are f^**
quently very rich in silver, and sometimes they contain gold.
GOSSIPIUM. The cotton-tree. See Cottok.
GOVERNOR. A mechanical arrangement usually attributed to Watt, for regu-
lating the motion of a steam-engine.
GRADU ATOR. A vessel em^oyed in vinegar manufacture. See Acetic Actd.
GRAINS OF PARADISE. The fhiit of several aingiberaceous plants; some-
times it is called MaUaguetta pepper. Pereira distinguishes between the two, but
it appears that they commonly pass for the same in commerce. Grains of paradise
are imported in casks, barrels, and puncheons flrom the coast of Guinea. They are
used to give a factitious strength and pungency to beer and cordials.
By 56 Geo. IIL c. 58, no brewer or dealer in beer shall have in his possession or
use grains of paradise, under a penalty of 200/1 for each offence : and no druggist shall
sell it to a brewer under a penalty of bOOL for each offence.
GRAIN TIN. See Tim.
GRANITEI, in the common and original acceptation of the term, denotes a rock,
composed of felspar, quartz, and mica. It oftentimes contains, in addition to these,
some other minerals.
These component minerals of granite, both essential and accidental, are united
together by a confused crystallisation, not only mutually penetrating and interfering
with each other, but sometimes the small crystals of one are completely enveloped in
the large crystals of a different kind of mineral, and it is a very common occurrence
fbr one or even more of these minerals to be developed in large crystals, in a granular
basis of the whole, so as to constitute a porphyritic granite. This character is gener-
ally imparted by the felspar, and rarely by the quartz or mica. — Boose.
The chemical composition of ordinary granite is generally as follows : -^
Silica 72-3
Alumina --- 153
Alkalies - - - - 7-4
Lime and magnesia and iron - . - . - 5*0
This rock consisU generally of about 40 per cent of felspar, 30 or 40 per cent of
quartz, and from 10 to 20 per cent of mica.
400 GRANITE.
The granites of ComvDoIl have been long celebrated for their exceeding . dnra-
bility. Sir Henry de la Beche thus describes the situation of the workable
granites : —
** Ther^ is much good granite on Dartmoor, though it is not alirays sufficiently
accessible to be carried long distances : the chief places where it is worked in large
quantities and afterwards exported are. Hey or High Tor on the east, and Dear King
Tor on the west. The granite from the former place is couTcyed by a tram-road to
the Stover canal, down which it is carried in boats, and afterwards down the Teign
to Teignmonth, to be shipped for its destination. That f^om the west side of the
moor is conveyed by the ffrince's town and Plymouth tram-road to the latter place
and shipped.
** The continuation of the Hingston Down granite is worked up the Tsunar near
New Bridge and exported from Morwellham. A very hard variety is obtained upon
the higher part of the Down, and has been employed advantageously for pavements.
• • • The chief quarries in the eastern or hard part of the Hensboroogh mass
of granite are those of (the late) Mr. Austin Trefiry, up the Par Valley, commonly
known as Lostwithiel granite. Extensive quarries are there worked, and the stone is
brought to the head of the canal near Pons-mill, upon which it is conveyed to Par
harbour, and there shipped. • • * The Cam Menelez mass has fiimished
the granite most commonly known as Cornish. It is nearly altogether shipped at
Penryn, where it is brought variable distances from different quarries in the vicinity,
many situated in the parish of Mabe.*'
Since the above report was written, the quarries at the Cheeswring near Liskeard
have been opened, and stone of a beaatiAil quality is raised and exported in large
quantities. The Lamoma quarries have also been worked ; the stone obtained fipom
them is of excellent quality, and it can be obtained of almost any size.
The quantity of granite exported from the several ports of Cornwall in 1855, is
estimated as being 473,716 feet, or about 35,000 tons, the value of which was at least
75,700/. Of Devonshire granites the quantities exported Arom the eastern and western
sides of Dartmoor was probably about 5,000 tons.
The following great works, amongst many others, have been constructed entirely or
in part of Cornish granites. The Penryn and Lamoma granites have supplied Port-
land Break- water ; Keyham Docks for the Steam Navy ; Commercial Docks, Ix)ndoa;
the Hull, Great Westem, and Birkenhead Docks, and the National Works at Chatham
and Portsmouth, together with the Scutari Monument The plinth for the railings of
the British Museum was from the Camsew quarries, and the towers, including the
lodge, for gates, &c., from Constantine. From Lamoma blocks of 12 feet square are
readily obtained ; these quarries produce about 60,000 feet per annum : some stooes
have been raised 25 feet in length and 1 1 feet in diameter.
The Cheeswring granite has been used in the London Docks, Westminster Bridge, the
Thames embankment, Rochester Bridge, the Docks at Copenhagen, the Great Basses
Lighthouse near the island of Ceylon, and for the tomb of the Duke of Wellington in
the crypt of St Paul's Cathedral. These quarries produce fVom 8,000 to 10,000 tons
of stone per annum, and about a similar quantity is annually shipped from the quarries
near Par.
Hie granites of Scotland are chiefly produced from the county of Aberdeen.
The granite of Aberdeen, especially from the quarries of Dancing Cairn, Rubislaw,
and Tyrebagger, is much used in the metropolis for kerb and paving stones; some
red granite is also quarried. Around Peterhead the red granite prevails, hence it is
usually distingaished as the Peterhead granite. The principal quarries are those of
Black Hill, four miles west of Peterhead, belonging to the Govemors of the Merchant
Maiden Hospital of Edinburgh; those on the estates of the Earl of Errol, — at Bod-
dam, — at Longhaven, — at Caimgall and at Rova. The Sheemess Docks were built
mostly with stone from these quarries. The Stirling Hill quarries, at Bodham, fur-
nished the pillar of the Duke of York's monument ; the Seafield quarries the abacus.
The beautiful pillars in -the library of the British Museum were obtained from Long-
haven ; the cost for transport, at the time they were worked, bein£^ something almost
fabulous, so great were the difficulties attending their removal. The pillars m Fish-
mongers' Hall are from the Stirling quarries, as are also the bases of the monuments
of Pitt and Fox ; and the polished pillars of the Carlton Club House, in Pall Mall,
are from the quarries near Peterhead.
The granites of Ireland — The most extensive granite district in Ireland stretches
south from Dublin, through the counties of Wicklow and Carlow into Kilkenny ; it
occurs on the south-eastern coast of Down, and around Newry ; the range of the
Moume mountains is granite, which again appears in small and isolated protrusions
in Derry and Tyrone, and in Cavan. In the westem portion of Donegal there is a
large extent of this rock, which here partakes of a gneissose character ; and again, in
GRAVITY, SPECIFIC. 401
the west of Galway, granite coven a considerable area. The granite of the Wicklow
range is the most extensively used. It varies in its qoality, that near Kingston being
coarse and hard, while that from Ballyknocken, or Golden Hill, is much finer, ana
therefore fitted for ornamental work. Th«k granite of Down is of a darker colour and
finely crystallised. It is extensively quarried at Newry, and sent by water to the
north of Ireland.
The Galway granite is of a reddish colour, containing large crvstals of flesh red
felspar. That of Mayo is of a dark bluish grey colour, while that of Tyrone is
reddish.
The Irish granite averages 170 lbs. per cubic foot, its extreme weights being 143
lbs. and 176 lb& After 88 hoars' immersion in water it was found that a cubic foot
of the granite of Newry and Kingston absorbed about a quarter of a pound, that of
Carlow nearly two pounds, and the granite of Donegal four pounds of that fluid*
These facts are important in connexion with the use of these rocks for building pur-
poses. — WUMinson a PracticcU Geology and Ancient Architectwre of Ireland, — Sir JR.
Kan^a Industrial Beaources of Ireland.
Granite is worked to a small extent at Shap Fell in Westmoreland, and at Mount
Sorrel in Leicestershire. The rocks worked as and called the Grooby granite may
perhaps be more properly termed Sienites, in some cases assuming the clutracter of a
sienitie granite, in others of a sienitic greenstone. These are worked extensively for
** pitching " and for macadamising roads.
' GRANULATION, is the process by which metals are reduced to minute grains.
It is effected by goring them, in a melted state, through an iron cullender pierced
with small boles, into a body of water } or directly upon a bundle of twigs immersed in
water. In this way copper is granulated into bean shot, and silver alloys are granu-
lated preparatory to refining. See Mbtallurot.
GRAPE SUGAR. So oilled ttom. its being produced in the grape. See Sugab.
Its formula is C«H'*0".
GRAPHITE {Phmhagine, Fr. ; Reiaablei, Germ.) is a mineral substance of a lead
or iron grey colour, a metallic lustre, soft to the touch, and staining the fingers with a
lead grey hue. H»l to 2. Spec grav. 2*08 to 2*45. It is easily scratched, or cut
with a steel edge, and affords a black streak, displaying the metallic lustre in its in-
terior. B.B. infusible both alone and with reagents : but bums with great difficulty
in the outward flame without flame or smoke, generally leaving a residue of oxide of
iron. It consists of carbon in a peculiar state of aggregation, with an extremely
minute and apparently accidental impregnation of iron. Graphite, called also plum-
bago and black lead, occurs in gneiss, mica slate, and their subordinate clay slates and
limestones, in the form of masses, veins, and kidney- shaped disseminated pieces.
It has been found also among the coal strata, as near Cumnock in Ayrshire.
This substance is employed for counteracting friction between rubbing surfaces
of wood or metal, for making crucibles and portable furnaces, for giving a gloss to
the surface of cast iron, &c. See Plumbago.
GRASS OIL. A fhigrant oil which is extracted from a peculiar Indian grass \
it is generally called* the grcua oil of Nemanr^ and it probably bears a close relation to
the spikenard of Scripture. '
GRATE, a mining term. A metal plate pierced with small holes; it is fixed in
front of the stamps in which the ore is pounded, and through the holes the finely
divided matter makes its escape.
GRAUWAOKE or GREYWACKE. Grau, grej ; waoki, cky. A German
name, often adopted by geologists for some of the most ancient fossiliferous strata.
The rock is often of a grey colour, hence grau, German for grey; waehe being a
provincial miner's term.
The Grey wacke rocks are stratified or slaty rocks, which may be regarded as bear>
ing the same relation to clay slates that argillaceous sandstones and conglomerates
bear to common clay. Argillaceous slate, by including rolled fragments or minute
grains of quartz sand, with or without mica, becomes the grauwache or grauwacke date
of Werner. Although at one period the term grauwacke or gregwaeki was employed
to include the Cambrian and Silurian slates, the term has now nearly dropped out
of the geological nomenclature.
GRAVITY. The term usually applied to the action of the earth's gravitation.
GRAVITY, SPECIFIC. The difference in weight between a given mass of any
body weighed in air, and the same mass weighed in water, is its specific gravity. For
a description of the several methods by which the specific gravity of any body, either
solid, fluid, or aeriform, may be determined, we must refer to Ur^a Dictionary of
Chemiatry, or to any works treating of the manipulating details of physic or chemistry.
The following table may be found useful s —
Voi^ IL D D
402
GREEN EBONY.
TahU of Specific Gravity,
MSTALS.
aroma, Eaktbs, ftc
WeightJ
Number
Weight
Weight, Weiglit
Now^ber
Names.
water
or cubic
ofa cubic
Nam^
water
ofacubM
ofcwbic
being
Inches in
inch, in
^ABIOTe
being
foot, fal
iactina
looa
alb.
Ibt.
1000.
Ibk
too.
Platina
19500
1-417
•7063
Marble, ayerage -
2720
170-00
13
Pure gold -
19258
1-435
•6965
Granite, ditto
2651
165^68
\n
MercuTT -
13560
2-038
•4904
Purbeck stone -
2601
162-56
I^ad -
11352
2-435
•4106
Portland ditto -
2570
160^8
14
Pure silver
10474
2638
•3788
Bristol ditto
2554
159-62
14
BUmuth -
9828
2-814
•3662
Millstone -
2484
155-85
lU
Copper, cast
87S8
3-146
•3178
Paying stone
8415
150-93
— Bheet
8910
3*103
•3225
Craigleith ditto -
236S
147-62
15
Brass, cast -
.7824
3-533
-3036
Grindstone
2143
133-93
16»
— sheet
8396
3-293
•3037
Chalk, British -
S781
178-81
1«|
Iron, east -
7264
3-806
•263
Brick-
2000
125-00
17
— bar -
7700
3-592
•279
Coal, Scotch
1300
81-15
Si
Steel, soft -
7833
3-530
•2833
— Newcastle -
1270
7937
— hard -
7816
3-637
•2827
— Staffordshire
1240
77-50
29
Tin, cast -
7291
3-790
•2686
— Cannel
1238
77-87
99
Zinc, cast -
7190
3-845
•26
GREEN EBONY of Jamaica. This is a wood of a brown green eoloor. ft is
deriyed from the Amerimnvm Ebenus^ and is used in tomeiy and for marquetry woik.
— See MARQUBTRy and Parqubtrt.
GREENHEART. A wood brought from Jamaica and Goiana, the prodaoe cf
the Lavrui cMoroxyUm, It is used in shipbuilding. Bancroft, in his Gmaao, thus
describes it : " The Sipiera or Greenheart tree is in sise like the locust-tree, about 60
or 70 feet high ; there are two species, the black and the yellow, differing only in the
colour of their bark and wood."
GREEN PAINT& (^Ondewr* verUa^Tr. i Grvne pigmnte, Genn.) Green, which
is so conmum a colour in the yegetable kingdom, is rare in the mineraL There is
only one metal, copper, which affords in its combinations the yarions shades cf
green ia general use. The other metals capable of producing this colour are, chro-
mium in its sesqniozide, nickel in its hydrated oxide, as well as its salts, the sele-
niatc, arseniate, and sulphate ^ titanium in its prussiate ; and some of the salts of
uranium.
Green pigments are prepared also by the mixture of yellows and blues ; as, for ex-
ample, the green of Rinman and of Gellert, obtained by the mixture of cobalt blue and
flowers of sine ; that of Barth, made with yellow lake, prussian blue, and clay ; but
these paints seldom appear in the market, because the greens are generally extempo-
raneous preparations of the artists.
Mountain green consists of the hydrate, oxide, or carbonate of copper, either factitious
or as found in nature.
Bremen or Brunswick green is a mixture of carbonate of copper with chalk or lime,
and sometimes a little magnesia or ammonia. It is improved by an admixture of white
lead. It may be prepared by adding ammonia to a mixed solution of sulphate of cop-
per and alum.
Frise green is prepared with sulphate of copper and sal ammoniac
Minis green is an arseniate of copper, made by mixing a solution of acetate or snl-
phate of copper with arsenite of potash. It is in fact Scheele's green.
Sap green is the inspissated juice of buckthorn berries. These are allowed to fer-
ment for 8 days in a tub, then put in a press, adding a little alum to the juice, and
concentrated by gentle eyaporation. It is lastly put up in pigs' bladdess, where it
becomes dry and hard. See Colours, Table of.
GREENS AND. The term greensand applies to the strata lying between the Chalk
and the Wealden deposits. They are of marine origin, as is denied by the preseooe
throughout their entire thickness of sea-shells, and are divided into an upper and
lower series, separated by a stratum of day, called Gault (which see). The Upper
Greensand, which underlies the Chalk MarJ, is composed chiefly of calcareous saiid in
GREENSAND. 403
the lower, and Sandstone and layers of Chert in the nppermoet part (see Firestone).
The sandstone affords a good and durable building stone. The Chert is Well adapted
from its toughness for making roads, and the sandy portion, in addition to its useful-
ness as a component of mortar, furnishes an excellent agricultural soil, from the cal-
careous matter it contains, in addition to the large percentage of soluble silica entering
into its composition, which sometimes amounts to more than 40 per cent In Sussex,
Surrey, and Kent, the land based upon the Upper Oreensand is known by the name
of malm, and produces the greater part of the hops for which those counties are eele-
Vhited. In the neighbourhood d Godstone and Merstham, in Surrey, extensive
quarries are driven into the hills, at the base of the chalk downs, for the purpose of
procuring the soft and chalky stone which occurs there in the higher portion of the
Upper Greensand, for which there is a large demand in London, for cleanmg door-steps,
and stonework in the fronts of houses, under the name of hBarthstones, A plentiful
supply of pure water is borne up by the impermeable strata, forming the uppermost
part of the upper greensand, which finds its way out of the ground near the base of
the chalk, and forms the sources of many streams and rivers.
The Lower Greensand consists of alternations of sands, sandstones, and cla3r8, which
are often very ferruginous, so much so sometimes as to constitute a siliceous ore of
iron, as is the case at Seend in Gloucestershire, and Shotover in Oxford. The fer-
ruginous sands form the iron -sand of Dr. Smith. The Lower Greensand, also, contains
beds of Fuller's Earth, which are worked at Reigate, and furnishes a durable and useful
building stone, known by the name of Kentish Rag, and quarried extensively in the
neighbourhood of Maidstone.
The term Greensand, though applied to deposits of considerable thickness, is, in fact,
only strictly applicable to certain minor portions of them, which are marked by the
presence of minute grains of green silicate of iron (the glauconite of American miner-
alogists). These impart a colour to the beds in which they occur, which has given
the name to the entire formation. — H. W. B.
GREEN SLOKE. Ulvd latiasimoj the broad green laver. See Auim.
GREENSTONE. Mineralogically, greenstone or diabase is pyroxene with Labra-
dorite or oligoclase. Popularly, the term is applied to varieties of trap. ** Green-
stone is a dark and heavy blackish-green or brownish rock, consisting of felspar
and hornblende ; it usually has a crystalline texture, but is sometimes compact**
— Dana.
GREEN ULTRAMARINE. This is artificially prepared in France and Germany,
and employed, instead of the arsenical greens, for printing upon cotton and paper. See
GREEN VITRIOL. Sulphate of iron.
GRENADA COCUS or GRENADILLO. This wood, imported from the West
Indies, is called red ebony by the French cabinet-makers.
GREY DYR ( Teinture grisSy Fr. ; GraufBrbe, Genu.) The grey dyes, in their
numerous shades, are merely various tints of black, in a more or less diluted state,
from the deepest to the lightest hue.
The dyeing materials are essentially the tannic and gallic acid of galls or other
astringents, alone with the sulphate or acetate of iron, and occasionally wine stone or
crude tartar. Ash grey is given for 30 pounds of woollen stuff, by one pound of gall nuts,
^ lb. of wine stone, and 2^ lbs. of sulphate of iron. The galls and the wine stone being
boiled with from 70 to 80 pounds of water, the stuff is to be turned through the
decoction at a boiling heat for half an hour, then taken out, when the bath being re-
freshed with cold water, the copperas is to be added, and, as soon as it is dissolved, the
stuff is to be put in and fully dyed. Or, for 36 pounds of wool ; 2 pounds of tartar,
^ pound of galls, 8 pounds of sumach, and 2 pounds of sulphate of iron are to be
taken. The tartar bein^ dissolved in 80 pounds of boiling water, he wool is to be
turned through the solution for half an hour, and then taken out The copper being
filled up to its former level with fresh water, the decoction of the galls and sumach is
to be poured in, and the wool boiled for half an hour in the bath. The wood is then
taken out, while the copperas is being added and dissolved ; after which it is replaced
in the bath, and dyed grey with a gentle heat.
If the grey is to have a yellow cast, instead of the tartar, its own weight of alum
is to be taken ; instead of the galls, one pound of old fustic ; instead of the copperas,
} of a pound of Saltzburg vitriol, which consists, in 22| parts, of 17 of sulphate of
iron, and 5} of sulphate of copper ; then proceed as above directed. Or the stuff
may be first stained in a bath of fustic, next in a weak bath of galls with a little
alum ; then the wool being taken out a little vitriol (common or Saltzburg) is to be
put in, previously dissolved in a decoction of logwood ; and in this bath the dye is
completed.
D D 2
404
GRINDING AND CRUSHING MACHINERT.
Pearl-grey is produced by passing the stuff first tbroagh a decoction of sumach ud
logwood (2 lbs. of the former to 1 of the latter), afterwards through a dilute sdation
of sulphate or acetate of iron ; and finishing it in a weak bath of weld containing a
little alum. Mouse-grey is obtained when^ with the same proportions as for ash-grey,
a small quantity of alum is introduced.
For several other shades, as tawny-grey, iron-grey, and date-grey, the stuff
must receive a previous blue ground by cupping it in the indigo ^at ; then it it
passed first through a boiling bath of sumach with galls, and lastly through the
same bath at a lower temperature after it has received the proper quantity of solatioo
of iron.
For dyeing silk grey, fustet, logwood, sumach, and elder* tree bark, are emplojed
instead of galls. Archil and annotto are fireqnently used to soften and beautify the
tint
The mode of producing grey dyes upon cotton has been explained in the artida
Calico Printimo and Dteino.
GRINDING AND CRUSHING MACHINERY. Crushing MUL This
machine was introduced into the mines of Cornwall and Devon in the early part of
the present century. In its simplest form it consists of two rollers mounted in a itrong
iron frame, and kept in contact by means of screws ; motion is communicated to one
of the rolls, either by a water-wheel or steam-engine, but the other is made to rexohe
by the friction generated between the moving roll and the staff to be crushed. Tbii
mill is usaally employed for reducing miner^ substances which have already received
some mechanical preparation, but machines have been contrived with a series of rolls,
set below each other, into which the stuff is introduced as brought from the lode
under -ground. In order to effect this operation, the upper rolls are fluted, and tbe
lower ones have various speeds and diameters, but it may be remarked Chat althoogh
this arrangement has been somewhat extensively employed in the north of England,
yet it has found few advocates either in Wales or Cornwall.
The practice of keeping the rolls together by screws acting on the bearings is ob-
jectionable, since the entrance of a piece of steel, or other hard substance cl gretter
923
width than the fixed opening between the rolls, immediately produces a stoppage ao^
strains the apparatus, or otherwise causes serious breakages to some of the part*-
order to obviate these evils, the rolls are usually adjusted and kept in positK^o j
weighted levers pressing on their axis. ^^
As the machines employed in Cornwall may be considered the most effecUte
GRINDING AND CRUSHING MACHINERY.
405
operation u well as complete in their constraction, that type is selected for repre-
sentation.
B B {fig, 923), are the cmshing rollers fitted in a strong frame-irork of cast iron,
which is stayed by a wrought iron bar 6, and firmly bolted to longitudinal beams in-
serted in the walls of the crushing-house. The rollers revolve in bearings, which are so
arranged as to slide in grooves, and therefore admit of the cylinders being brought
nearer to or separated fiirther from each other. To keep the rollers in contact and
yet allow the action to take place, a weighted lever a is placed on each side, which by
means of tension bars connected with one of the bearings, keeps a constant pressure
upon the roUers. The ore to be crushed is lodged upon a floor c, and introduced into a
hopper D, tnan. which it ialls between the rolls; the requisite crushing pressure being
attained by increasing or decreasing the weights applied to the end of the lever. Tiie
crushed ore passes from between the rollers b b into the higher extremity of an in-
clined cylinder s, made of coarse gauze, or perforated plate, which being set in
motion by the same power as the rollers themselves, separates the pulverised material
into two classes. That portion which passes through the sieve falls into a waggon
placed on the floor of the house, whilst the other, which is too large to escape through
the openings, is carried to the lower end of the cylinder from whence it passes into an
inverted bucket-wheel r, by which it is again conveyed into the hopper to be re*
crushed.
The modifications to the foregoing arrangement may be thus briefly noticed.
In some machines the feed hopper is made of sufficient capacity to hold from 20 to
924 •
925
TS-mrTi.iiu.- -riri M
I ■ l.fe" iiJi Ufr '^-t •!
f^r^^rw^
kvwv
v4
=^
&
1-^S
25 cwt. of stufi^ which is introduced by means of a tram waggon, and renders hand
feeding unnecessary. The shoot conveying the crushed ore to the rotating sieve, e,
IS sometimes divided at (he bottom into two parts, one to deliver rough, and the other
D D 3
406 GRINDING AND CRUSHING MACHINERY.
fine staff. In connection -with each division, is a cylindrical riddle reTolring and
separating the work according to the fineness or coarseness of the mesh employed.
A circular sieve divided midway into two parts, each of a different mesh, is in
some instances, advantageously substituted for two sets of sieves ; whilst, in other
cases, circular sieves are omitted, the operation of sizing being peiformed by fixing
perforated plates on the periphery of the inverted wheeL
Instead of one roll being drawn towards the other, they are more commonly kept
in contact by direct pressure, which is effected as shown in figa. 924, 925.
A, lever hung to the cast-iron frame b at c, and pressing upon pin at d. When it
is required to change the rollers, the pressure resulting from the lever ▲ and weighted
box E, is relieved by means of the screw tackle f.
The considerations which should be attended to in constructing a crushing mill,
are, first to make all the parts sufficiently strong to meet the varying resistanpea which
continually occur in crushing. For this purpose, the framework to receive the rolls
ought to be of good cast iron, the axles of the rollers of best wrought iron, and the
cylinders of the hardest and most uniform metaL 2ndly. To design the machine, ao
that the matter to be crushed may be readily delivered into the hopper, sized by the
circular sieves, for the dressing process, and such portions as are not properly crashed,
returned to the rolls without the intervention of manual labour. In order to effect
this, the invertedj or raff wheel d, jfSo. 925, shown in section, ought to be made of
sufficient diameter to allow the sti^ on being discharged, to descend by its own
gravitv, into the feed-hopper. Srdly. To extend from the axis of the rollers, long
tnmblmg shafts, a a, fig, 925, and fix on their ends the driving wheels b b, allow-
ing a little play in the plummer blocks, so that any undue opening of the roIH
may not vary the pitch line of the wheels, b b, to such an extent as to endanger the
safety of the teeth. 4thly. To construct the roll so that it may be readily changed,
yet maintained on its axis without slipping when in motion. One of the most efficient
plans for this purpose, is shown in the folloving woodcut, in which a is the axis or
arbor, and D the roll.
926
0^3X]
It will be seen that the cylinder roll is fitted with four internal projections ; these
are of the same length as the portion of the groove marked bb', but no wider than
the narrower part of the groove c. When the cylinder is to be fixed on the axis, the
studs are introduced into the recesses c, and the cylinder advanced into its working
position, when it is turned until the studs fit into that portion of the recess between
B b', and which are then wedged to the roll by a close-fitting cutter.
Sthly. The diameter of the rolls should be decreased, and the length increated in
proportion to the fineness of the stuff to be crushed, since a fine material requires a
longer line of contact, and not so large a grip as coarser substances.
Id practice it has been found advantageous to make the roller placed on the driving
shaft somewhat longer than that which is opposite, and to work the rolls by spur
gearing rather than by friction, since the latter is proved to fhmish less economical
results than the former. It has also been found injudicious to harden the rolls by
chilling ; hence ordinary sand cast rolls are most frequently employed.
The speed of the rolls varies from 45 to 60 feet per minute, but this necessarily
differs with the character of the stuff to be crushed. Again great variation is ex-
perienced in the quantities crushed within a given period, since a small amount of
moisture in vein stuff of a certain class, makes it cake, and will thus considerably
reduce the produce of the mill. On the other hand, if the matter operated upon, be
very dry, heavy, and brittle, as in the case of some varieties of lead ore, the produce
may be much increased, since the mill can be driven at a great speed ; a less hulk
will have to pass for a gi^en weight, and there will be a smaller quantity of material
carried back by the raff wheel to be recrushed.
Variable speeds have sometimes been tried in order to produce friction together
with pressure at the line of contact, but it has been found that any departure from a
uniform speed on the two surfaces, absorbs a considerable additional amount of power,
without materially augmenting the results.
The various dimensions and velocities of the rolls, crushing force, and power em-
ployed, effective yalue of different mills, &c, now in use, may be gathered by referring
to the following table : —
• i
6BINDING AND CRUSHING MACHINEBT. 407
Kahb or HiMi.
Gratsington MinM
Cwnf itvUb Nob I
^ Nasi
Gogfnao •
Cwn Brilii
Ltsbotue Vo. 1
w No.S
06rW60t
(ddaeope, (t
ofroUs,lliil6d,
other plain).
Boat Dwrai
CaAiCwmBi
IVVVBO
>. 8 .
Uaboroe No
Llandudno •
VHwal Fricndihip
Pontglbnad .
Fabrics la Coo-
fCante, Spain,
No.1 . .
tt No* %
n NaS .
n No. 4
Rou.1
la.
S7
14
ar
ao
V
V
«7
27
14
M
SO
18
18
S5
84
S4
S7
S4
97
ij
la.
IS
14
14
14
14
14
15
15
14
18
18
18
16
15
IS
IS
SS
15
15
IS
15
3
8^ la*
51 J5M
48S0
4749
5841
7S54
89M
7683
7633
14
6
5
8
15
10
1S||
7
10
10
16
15
11060
ootut
4090
648S
19706
8670
18075
16448
11800
1S790
14464
19060
Cvt.
91
78|
78
85
89
298
INO
334
837
6
907
84
169
61
138
86
456
147
110
84
93
tXaoiMOTiir
la.
91
84
SO
84
90
86
88
88
48
43
88
86
89
88
86
86
60
I
I
8^ la.
?
9
9
9
9
m
16
I
I
II
87
48
84
M
86
80
80
80
No Sifter.
94 I 86 I 16 I 45
90 48 I 16 971
99 186 I 95 I 80
Flttk Sifter. l-lOUi Uicb.
94
98
.C94Ur.
'n9un.
25
85
95
96
86
44
86
86
84
64
45
58
100
100
45
8600
56
8600
80
60
91
80
80
48
45
10>6
16-0
16 0
160
16 0
16-0
16-0
15-0
14-0
160
Jacob's
ladder.
180
150
M
15-0
160
Jacob's
ladder.
198 ft.
Birm.
itto.
Ron
Powa
9
•I
M
n
Steam
power.
15
iO
87
96
87
80
90
St
85
80
90
48
43
60
95
95
90
43
80
90
17
65
90
50
ovt.
IS
18
it
19
19
ArroMtre or AiAoiia.—- Thb mtchine is extensiTelv employed in l3ie mining districts
of Mexico, for grinding siWer ores previoos to their nmnlyimation.
It consisti of a strong wooden axle a (Jig, 927), moving on a spindle in a beam b aboye
927
it, and resting on an iron pivot beneath, taming in an iron bearing, which is inswted
into a post of wood c, which rises abont a foot above the ground in the centre of the
•riMlre. The shaft a ■ crossed at right angles by two strong spais »»,wJmc1i form
ftmr«rma,ea€hiamt6feet hmg. one exoepttd, whkA ia 9 feet Iobj, toiitoit
mules being attadwd to it ; by ^ arm the machine is woorked. The mnointt m tjer.
dd4
uper-
408
GRINDING AND CRUSHING MACHINERY.
formed by four large porphyritic or basaltic stones, two of which are shovn, s i.
These are loosely attached by thongs of leather, or small sixed rope, to the four arms, and
are dragged round over the ore, which is put in with water, ontU it is ground to tfery
fine slime or mud, called the lama. One of these machines, when in good working oondi*
tion, will grind from 600 to 800 pounds weight of ore in twenty-four hours. In Gu-
naxuato, where the best and finest grinding is obtained in the arrastres, the lining or
foundation and the grinding stones, are of course, grained porphyry, and form a
rough surface. The cost of this apparatus in Mexico, including Uie paTing of the
bottom, and the four metapileM or stones, is on an average 7/. The original weight
of a metapile, is about 700 pounds, its dimensions are 2 feet 8 inches long, 18 inches
broad, and 18 inches deep. Notwithstanding the hardness of the stones empbyed,
they are so worn as to become unserviceable m the course of ten or twelve weeks ; the
bottom, howeyer, is only replaced once in twelve months.
This apparatus is well smted to patio amalgamation, but it affords bad resnlts fof
the power expended.
Edffe mill, — This machine is employed for the purpose of reducing gold and
silver ores to an impalpable powder. It is also used extensively in grinding fl'mu
stones, slags, and a variety of other products. However much the details of tbii
apparatus may vary, its principle is the same in all cases. Two vertical runners
rotate on the outer circumference of a flat or slighUy conical basin and afibrd a
frictional or g^nding area equal to the difference of distance performed by the ixner
and outer edges*
The subjoined woodcut, fig, 928, represents a mill constructed at the Mould Foondiy,
928 ^
Flintshire, a, rotating pan, resting upon frictional wheels B ; c, vertical shaft finnly
kej(^ to pan a, to which motion is communicated by wheel gearing n. The nmn^^
K E revolve on arm v, and may be of cast iron or of stone bound with a riof of iro"*
GRINDING AND GBUSHING MACHINERT. 409
TheM rnnnert haTe do prognsiiTe motion but hare free pliij to rue or (Ul on axii c,
and ia the M*j aloll oa.
The following dimensioiu tod pMticalan are derired from one of the edge milli
reeentlj wurkiog at the Fabrics l.a Constante in the proTince of GoadiltuaTa, Spain.
IKameterof edge roDtieT ... - . 6 feet
Widtb of da do. Centre SO in. edge 16 in.
■ Weight ofdo. do. • - - - .3 toni IS cwL
Speed of mnner - - ■ - -■. . soo feet per nunale.
Diameter of iaterior circle of nuiner - - - * feet
Gauge of atnff pretion* to its being grosnd - - 10 holei to the lineal inch.
Do. after it lesvea the miD - - . 60 „ „
Quantitj of itnff redoced per 1 0 hoon - - - 3G0 Iba.
HoTM poirer employed ...--- 7,
In wme machines erected at the Real-dei-Moote mines in Mexico the itonea irere
6 feet in diameter and la inehea wide. The; were fltled with a ring of wroagbt iron
3 inches thick. Each pair of ronnen rerolTed roond a centre on lis own aiii^ in a
cast iron basin of Irhich the bottom vas 7 inches thick. At first good results were
oblained,each mill if kept constantly at work groondDearljr ten tons per week; but as
their axles, and particularly the wrought iron rings and cast iron bottoms, begnn to
wear hollow and to lose an even sar&ce, the grinding rapidly diminished, and with
oneyear's work they were completely worn ont.
The chief ady an tage of this machine ia id simplicity of eonstmction and conseqaeat
small first cost ; bat all its parts reqoire to be mode of great strength, and tberafore of
proportionate weight ; hence, in addition to the rapid wear to which it is liable, this
*|iparatiis beoomei otjjeotionable for couDtries where transit of heavy machinery is
inore than ordinsjily diffienlt and expensive.
410 GRINDING ANt) CRUSHING MACHINERY.
been foand more effectnal than fhe horizontal milL It affords the largest area of
firictional surface for the least wear and tear, and accomplishes equal resnlts at a cost
not exceeding one-foarth of that incident to the edge mill.
The construction of the horizontal mill will be rendered intelligiUe by the aid of the
preceding illustration,^. 929, in which one pair of stones is shown in sectioiL ▲ is a
circular hopper, into which the stuff to be ground is introduced ; b b, small pipes of
sheet iron, for delivering the stuff between the surfaces of the runner c and bed-sume •
c'$ D, casing enclosing the runner inio which the ground material is deliyered;
E. hole in centre of runner ; f, driTing-shaft, with continuation shaft o, for giTing
motion to a Jacob's ladder if requisite ; h h', regulating screw for elevating runner c ;
J, driving-wheel ; K, crown-wheel ; L, wheel giving motion to pinions m h' ; and ir,
vertical shaft, to drive anj supplementary apparatus which may be requiring sodi, as
sizing sieve, &c. Four pairs of stones are usually driven by the wheel i^ The
surface of the runner is in contact with the bed-stone, fh>m the periphery to within
one-third of its diameter. The line of the runner then feathers upwards, in order to
receive the stuff freely and to equalise the resistance throughout the area of the bed-
stone.
The following particulars will convey much practical information relative to this
machine : —
Diameter of stones - - > - - 4 ftet 2 inches.
Thickness of bed-stone .... 12 inches.
Ditto runner - - - - - U inches.
No. of revolutions of stone per minute - - 108.
Gauge of stuff in stopper - - - - 100 holes to the square inch.
Ditto on delivery - - - - 8600 ditto.
Quantity of stuff ground per 10 hours - - 1 ton per pair of stones.
Power employed in horses . - - - About 5 per ditto.
Revolutions of sizing sieve - - - - 23 per minute.
Diameter of ditto - - - -30 mches.
Length of ditto .... log.
No. of holes per square inch in sizing sieve - 3600.
Character of runner . . - - . Coarse conglomerate.
Ditto bed-stone .... Compact quartz, moderately hard.
Duration of runner ..... Average 18 weeks.
Ditto bed- stone Ditto 22 ditto.
When dressed ---.-. Every third day.
From a scries of practical experiments made on the same stuff by these sevenl
mills, the following results have been obtained : —
•
1. Horizontal mill ...
2. Crushing mill ...
3. Edge mill - -
No. of Hotel
per aq. in. In
Sislng Sieve.
QttMitlty of
Stuff eround
in 10 fioun.
Horse Power.
OmtperToB.
3600
8600
8600
Cwt«.
20
13
13
5
5
7
M. d.
2 3
1 7
6 10
J. D.
The cnuhing machines which are in general use at Alston Moor and the northern
mines of this country, and where they have been employed for upwards of fifty year%
differ in some respects from those described.
This machine is composed of one pair of fluted cylinders, x x^fig* 930, and of two
pairs of smooth cylinders, z z, z' z', which serve altogether for crushing the ore. The
two cylinders of each of the tiiree pairs turn simultaneously in an inverse direction^ by
means of two toothed wheels, as at m,fig, 931, upon the shaft of every cylinder, which
work by pairs in one another. The motion is given by a single water wheel, of which
the circle aaa represents Ae outer circumference. One c^ the fluted cylinders is
placed in the prolongation of the shaft of this wheel, which carries besides a cast iroD
toothed wheel, geered with the toothed wheels e e, fixed upon the ends of two of the
smooth cylinders. Above the fiuted cylinders there is a hopper, which discharges
down between them, by means of a particular mechanism, the ore brought forward by
the waggons ▲. These waggons advance upon a railway, stop above the hopper, and
empty their contents into it through a trap-hole, which opens outwardly in the middle
of their bottom. Below the hopper there is a small backet called a dioe. Into which
the ore is shaken down, and which throws it without ceasing upon the eytindefs^
GRINDING AND CRUSHING MACHINERY.
411
in conseqnence of the constant jolts gWen it by a erank-rod, i (fig. 931), attached
to it, and moTed by the teeth of the -wheel m. The shoe is so regulated, that too
930
931
..*<*
mach ore can never hXl upon the cylinders and obstruct their movement A small
stream of water is likewise let into the shoe, which spreads oyer the cvlinders, and
prevents them from growing hot The ore, after passing between the fluted rollers,
fidls upon the inclined planes n n, which turn it over to one or other of the p^iirs of
smooth rolls.
These are the essential parts of this machine ; they are made of iron, and the smooth
ones are case hardened, or chilled, by being cast in iron moulds. The gudgeons of
both kinds move in brass bushes fixed upon iron supports k, made fast by bolts to the
strong wood- work basis of the whole machine. Each of the horisontal bars has an
oblong slot, at one of whose ends is solidly fixed one of the plummer- block or bearers
of one of the cylinders /, and in the rest of the slot the plummer-blocks of the other
cylinder g slides ; a construction which permits the two cylinders to come into contact,
or to recede to such a distance from each other as circumstances may require. The
moyable cylinder is approximated to the fixed ones by means of the iron leyers x x,
which carry at their ends the weights p, and rest upon wedges x, which may be slidden
upon the inclined plane n. These wedges then press the iron bar o, and make it ap-
proach the movable cylinder by advancing Uie plummer -block which supports its axis.
When matters are so arranged, should a very large or hard piece present itself to one
of the pairs of cylinders, one of the rollers would move away, and let the piece pass
without doing iiijnry to tiie mechanism.
Besides the three pairs of cylinders which constitute essentially each crushing machine,
there is sometimes a fourth, which serves to crush the ore when not in large nragments,
for example, the chats and cuttmgs (the moderately rich and poorer pieces), produced
hj the first sifting with the brake sieye. The cylinders composing that accessory
piece, which, on account of their ordinary use, are called chaU-roUerSj are smooth,
and similar to the rollers z z and z' z'. The one of them is usually placed upon the
prolongation of the shaft of the water-wheel, of the side opposite to the principal
machine ; and the other, which is placed alongside, receives its motion from the first,
by means of toothed wheel- work.
Maekworth's Patent Cruahing Boilers, figs, 932 and 933, fbr Coal and other
Minerals. These rollers are nude conical to equalise the wear, and as one roller
trayels faster than the other, the fragments are partially turned over, so as to
present their weakest line of fracture to the direction of the croshing force. Less
power is required to work these rollers. In lieu of the counterbalance weight usually
employed to allow the rollers to separate and pass excessively hard fragments, and to
bring the rollers together aoain, the machine is made more compact and simplified by
connecting a brass collars, in which the rollers work by a number of bands or cords^
of yoleamsed indiarubber strongly stretched. A compound cord of inditirubber,
3 inches in diameter, composed of 144 small and separate cords, when stretched
GBINDSTONE.
n of 3 iooE.
Tlie brsM coUan da «
GRINDSTONE. Orhidiiig-iloDM or grit-itones, are vMietlt. .- ~ ^^
of those whicb are celebrated being obtained from the sindslonei and [nillito>K p™
of the coal mciBurea. Mr. Knight deicribes the be«t known Tarietie*, which w* ""
following;— .
Newcastle GwMDETOBM. Tbew abound in thecoJ dirtricta of Nortlm™**''^
Dnrham, Yorlisbire, and Derbyihire. Thej are aelectad of different degreei of «**"
neu and decsitj, according to the work tbr which thej are reqnired. ^^^ . ,
BiLBToN GimiDBTOHs it ft limiUr de»cription of stone, of greBt ^*'*''*'^ ,™)
lighter colour, touch finer, and of a very sharp natore, and at the lame ti'^f.^L
hsrd. It ii ooDflned to a imall spot of limited extent near Biliton in eaBOta"^'
where it liei above the coal.
GUANO. 413
WicKXBBLET Grindstonss. These are obtained from a village aboat 9 miles east of
Sheffield, and are mnch used for the finer description of edge tools.
SHsnisu) Grinbstone. A hard coarse grit stooe, used for grindinglarge files and
the like ; it is obtained from Hardslej, about 14 miles north of Sheffield.
DsyoNSHiiis Batts, are obtained near CoUumpton,
Yorkshire Grit and Congleton Grit, are other rarieties from which grind-
atones are manufactured.
Burr SroNES. These are yerj celebrated; they are found at La Ferte-sous-
jouarre (Seine et Maine), and are said to be unequalled for grist mills. The combined
roughness and hardness of this tertiary quarts deposit give it immense advantaees.
The stones formed of this rock are usually pieced, which renders them very expensive.
GRIT. A peculiar hard sandstone. See Millstone Grit.
GROATS, EMBDEN. — When oats are deprived of their integuments, they are
called groats, and when these are crushed, they are known as Embden groats. Oatmeal
is prepared by grinding the grains.
GROVE or GROOVE. A mining term in Derbyshire. ** The mine, or work that
a man is employ^ in. Hence it is, if a question be asked. Where is Tom to day ? — He
is gone to the groove, he is at the groove. Sometimes it is used for the shaft, and
miners are commonly called groovers** — HoosotCs Minors Dictionary,
GROWAN. A local term applied in Cornwall to granite in an imperfect state,
either through decomposition, or irregular formation. It is said that the term is some-
times applied to the solid granite. We have never heard it so used, and the miners
and the quarrymen draw a well defined line between a granite and a growan.
GUAIACUM (Cratiac, Fr. ; Guajaharz, Germ.) Both the wood and resin are
imported ; they are used medicinally. It is known that, after the discovery of the
New World, wnen the first syphilitic diseases showed themselves in Europe, the origin
of which was erroneously ascribed to Santo Domingo, the guaiacum wood was con-
sidered as specific against this disease. The historian Herrera informs us that one
pound of the wood was at that period paid in Spain with seven piastres. The gum
which exudes ttom. tbe wood, and possesses, as it may be conceived, the medicinal
qualities in a much higher degree, is now valued at seven pence per pound. The
quantity exported from Santo Domingo in 1855 amounted to 11,883 lbs., valued at
£371. — ConsuTs Rqwrt
GUANO. This extraordinary excrementitious deposit of certain sea-fowls, which
occurs in immense quantities upon some parts of the coasts of Peru, Bolivia, and
Afirica, has lately become an object of great commercial enterprise, and of intense
interest to our agricultural world. More than twenty years ago it was exhibited and
talked of merely as a natural curiosity, but since that time the quantity imported into
England alone has risen ftom 30,000 to 300,000 tons (in 1855), the value of which was
estimated at no less than £3,000,000, as shown by the following numbers, fh>m the
** Statistical Abstract of the United Kingdom, from 1842 to 1856."
Imports of Guano, from
1842 to 1866.
Tear
Quantity imported
in Tons.
Year
QoantltT Imported
in Ton*.
1842
- 20,398
1850
-
- 116,925
1843
- 30,002
1851
-
- 243,014
1844
- 104,251
1852
-
- 129,889
1845
- 283,300
1853
-
-J23,166
1846
. 89,203
1854
-
-235,111
1847
- 82,392
1855
-
- 305,061
1848
- 71,414
1856
-
- 191,501
1849
- 83,438
During the last two years the quantity imported has somewhat diminished and hence
the rise in price, from £\\ to £14 per ton. It is curious that, though situated at so
great a distance from the sources of supply. Great Britain is by &r the largest con-
sumer of Guano, if we may credit the following.
Statement of the Quantities Exported from the Cincha Isiands during the Years 1850-1.
Tons of Guano sent to — issa 1851.
England - 102,421 150,653
France - - - - - - 1,429
United States 14,250 38,371
China 252
Total 118,352 189,024
Natural History and Geography, — Huano in the language of Peru, signifies dung; a
word spelt by the Spaniards, guano.
414 GUANO.
The conditions essential for the preservation of these excrements appear to be the
existence of a soil consisting of a mixture of sand and clay, in a country where the birds
are allowed to live for ages undisturbed by man or man's works, and where, moreover,
the climate is very dry, free not only from rain, but also from heavy dews.
These conditions appear to have been combined to a remarkable extent on the coasts
of Peru and Bolivia, between latitudes 13° north, and 21^ south of the equator, for
although beyond this region the flocks of cormorants, flamingoes, cranes, and other
sea-fowl, appear to be equally numerous, yet the excrement is rapidly carried away
by the rain or dew.
. It is then the dryness of the climate chiefly which has permitted the guano to accu-
mulate on these coasts, for, says Mr. Darwin^ — " In Peru real deserts occur over wide
tracts of country. .It has become a proverb that rain never falls in the lower part of
Peru." And again : — *' The town of Iquique- contains about 1 000 inhabitants, and stands
on a little plain of sand at the foot of a great wall of rock, 2000 feet in height, the
whole utterly desert A light shower of rain falls only once in very many years.**
Indeed since three fifths of the constituent parts of guano are soluble to cold water
Prof. Johnstone very justly observes thatt)**A single day of English rain would dissolve
out and carry into the sea a considerable portion of one of the largest accumulations ;
a single year of English weather would cause many of them entirely to disappear."
Such being the case, we might expect to find similar accumulations in other hot and
dry climates, as in Egypt, and in Africa, e. g. in the neighbourhood of the Great Desert;
and only a few years since a considerable deposit of guano was found in the Kooria
Mooria Islands.
In Peru the natives have employed it as a manure from the remotest ages, and have
by its means given fertility to the otherwbe unproductive sandy soils along their coast&
While Peru was governed by its native Incas, the birds were protected from violence
by severe laws. The punishment of death was decreed to the persons who dared to
land on the guaniferous islands during the breeding period of these birds, and to all
persons who destroyed them at any time. Overseers were appointed by the govern-
ment to take care of the guano districts, and to assign to each claimant his due share
of the precious dung. The celebrated Baron Von Humboldt first brought specimens to
Europe in 1804, which he sent for examination to Fourcroy, Yauquelin, and Klaproth,
the best analystical chemists of the day; and he spoke of it in the following terms: —
** The guano is deposited in layers of 50 or 60 feet thick upon the granite of many of
the South-sea islands off the coasts of Peru. During 300 years the coast birds have
deposited guauo only a few lines in thickness. This shows how great must have been
the number of birds, and how many centuries must have passed over in order to form
the present guano beds."
There appear to be three varieties in Peru ; the white, grey, and red, the first being
the most recent, and the last the oldest ; and in the midst of the great accumulations <^
the last kind, bones and feathers of birds are found (Frezier), as if to remove any doubt
which might still remain as to its origin.
Cincha Island Guano, — Much of the so-called Peruvian guano, is exported from the
Cincha islands. They are three in number, and lie in one line from north to south
about half a mile apart Each island is from 5 to 6 miles in circumference, and con-
sists of granite covered with guano in some places to a height of 200 feet, in successive
horizontal strata, each strata being frem 3 to 10 inches thick, and varying in colour
from light to dark brown. No earthy matter whatever is mixed with this vast mass of
excrement -At Mr. Bland's visit to these islands in 1842, he observed a perpendicular
surface of upwards of 100 feet of perfectly uniform aspect from top to bottom. In some
parts of these islands, however, the deposit does not exceed 3 or 4 feet in thickness:
In several places, where the surface of the guano is 100 feet or more above the level of
the sea, it is strewed here and there with masses of granite, like those fh)m the Alpine
mountains, which are met with on the slopes of the Jura chain. These seem to indicate
an ancient formation for the guano, isnd terraqueous convulsions since that period. No
such granite masses are found imbedded within the guano, but only skeletons of birds.
The accompanying wood-cut, ^^. 934, shows the nature of the formation.
The export of the guano has increased considerably during the last few years : be-
tween 300,000 and 400,000 tons are the annual amount at present, which is effected
by the aid of 900 working hands, 320 of them being Chinese, who enter into contracts
to serve their employer (the Government contractor), Don Domingo Eliaa, for 4 dollars
a month, renewing it, if they choose, with the increase of 4 dollars monthly, and
a bonus of 120. Those who work on their own account are paid 8 and 10 rials, 4 and
5 shillings, for each cart that they load. They live in a collection of dirty huts made
of bamboo and mud; they, nevertheless, appear to be happy and contented, and in
* lUteiirches In Geology and Natural HI«toi7;p. 438.
t On Guana Journal of the Agricultural Society of England, toI. ii. p. aiSw
seDenlw
to mnOTC it. It i) then coDrejed in vheelbarrom eilber direct Id lh« months of
the ihaol* on the «dge of lb« cliSi, or to the huge carti rnnDing on trBmnnys (br the
■ame pnrpoit. The colour Tuiei Ter; much — in lomc putt being m dark as tu-id
lepU, and in othen ai light aa that of a Bath brick.
416
GUANO.
found amongst the guano. Tlie guano heaps are surrounded bj a high fence to pre-
vent its being blpwn away by the wind, near the mouths of the canvas tubes or shoots^
which are sometimes 70 feet long, through which it is conducted to the boats. See
fig. 935.
As in Peru, the surface of the guano is covered with skeletons of birds, and bones
of seals. It is also perforated by numberless holes, running in every direction, like a
rabbit warren. These are made by a bird about the size of a pigeon, which remains
hidden during the day, sallying forth at dark to fish. Gold and silver ornaments are
also discovered occasionally, having been buried by the ancient inhabitants more than
three centuries aga
It is quite unnecessary here to insist on the value of guano as a manure. This is
a point established beyond all question by nearly every agriculturist in the kingdom;
and recorded by all classes of writers on agricultural subjects ; it has been the means
moreover of converting the sandy desert around Lima into a soil capable of rusing
abundant crops of maize ; hence the Peruvian proverb, *< Huano, though no saint,
works many miracles.*'
Commercial varieties, — The following appear to be the chief : —
1. Peruvian.
2. Augamos.
3. Ichaboe.
4. Patagonian.
5. Saldanha Bay.
6. Kooria Mooria.
7. African.
8. Indian.
Chemistry, — Guano being an article of so great value to the agriculturist as a manure,
and being liable not only to adulteration to a very great extent, but also varying when
genuine considerably in quality, it is highly important to have some means of ascer-
taining its value. This cannot be done satisfactorily by ever so experienced a dealer
by mere inspection, and therefore, both for the buyer and the seller, resort is necessary,
for a knowledge of its compound parts, to the analysis of the chemist.* Such being the
case, we must first ascertain the composition of genuine guano, and then inquire upon
which of its several constituents its value as a manure depends.
The following is one of the earliest analyses by Fourcroy and Vauqnelin, of a sample
of guano presented to them by Baron Von Humboldt, showing the composition in 100
parts : — ' .
Urate of ammonia - - . .
Oxalate of anmionia . . .
Oxalate of lime - . . .
Phosphate of ammonia - . .
Phosphate of ammonia and magnesia
Sulphate of potash - - - .
soda - . - -
Sal ammoniac . - -
Phosphate of lime -
Clay and sand
Water and organic matter
90
10*6
7-0
6-0
2*6
6-5
3-8
4-2
14-3
4-7
32-2
But perhaps the constitution of guano is better exhibited by the following analysis
of three sorts by Denham Smith.
American Guano. — Analysis of three sorts by Denham Smith.
I. Constituents soluble in hot Water (in 100 parts of guano).
Phosphate of lime ...
Phosphate of soda ...
Phosphate of ammonia and magnesia
Uric acid
Urate of ammonia ...
Organic matter ....
I.
0-186
0120
0-564
2-516
15*418
1180
II.
0-784
0-860
IIL
0110
0-133
0-756
* LleUg*! '* Chmnlstxy In Its appUcationi to Agriculture and Pbyilologr/* p. 172.
GUANO,
417
3. ConMtituentt toluhU in cold water (in 100 parts).
Water - - -
Sulphate of potash
Salphate of soda
Phosphate of potash -
Phosphate of soda
Phosphate of ammooia
Phosphate of lime
Oxalate of ammonia -
Oxalate of soda -
Chloride of potassium
Chloride of sodiam -
Chloride of ammonium
Organic matter -
22*200
8-00
6*33
7-40
2*55
1*500
II.
20*420
23*944
7-732
6*124
9*39
0*668
HI.
7*700
19*177
4*947
3*60
10*563
4*163
28*631
3-030
2*553
S. ConMtituentM insohtbU in water ( im 100 parts).
Phosphate of lime
Phosphate of magnesia
Oxalate of lime ...
Sandf &c. ...
Peroxide of iron and alomina
Humus . - - .
Organic matter ~ . -
Water - . - -
Loss- - - -
19*750
2030
2*560
15*60
2*636
3*456
0*044
II.
6*270
0-874
10-958
0*720
0*862
4*974
0*498
IIL
13*113
2*580
0*420
0150
0-836
We may also quote the following analysis by Dr. Ure, of guano, imported from
Bolivia, by the **Mary Anne," being the first cargo thence imported.
It was of a pale yellow-brown colour, dry, partly pulverulent, partly concreted, in
small lumps. Its mean specific gravity was 1*63.
The McluhU portion was found to contain : ~*
Urea - - - . -
Sulphate of potash ...
Chloride of sodium . . •
Phosphate of ammonia
Oxalate of ammonia . - «
5*0
7-9
5*0
5*5
0*6
240
The inaciuhle portion contained : —
Silica ....•.•.. 2*25
Phosphate of lime - - - • - - •9 00
Phosphate of magnesia and ammonia - - - •1*25
Urate of ammonia - - - - - - -15 27
Undefined nitrogenised organic matter, yielding by
combustion wi£ soda lime 17*05 parts of ammonia - 41*73
69*50
The total quantity of ammonia yielded by it, was 20*95 per cent.
Vol. II. E E
418 OUANO.
Analjfsis of Cincha Island Guano, (^UreJ)
Matter soluble in water - - - - - 47*00
consisting of —
Ammonia
Sulphate of potash, with a little sulphate of soda - - 6*00
Muriate of ammonia .-.--.- 3*00 0-95
Phosphate of ammonia ...... 14-32 4*62
Sesquicarbonate of ammonia - - - - - 1*00 0*34
Sulphate of ammonia ..--.-. 2*00 0'50
Oxalate of ammonia ------- 3*23 0*89
Water 8*60
Soluble organic matter and urea ----- 8*95
47*00
Matter insoluble in water - 53-00
consisting of —
Silica *- 1-25
Undefined organic matter ------ 9*52
Urate of ammonia ------- 14-73 1-23
Oxalate of lime 100?
Subphosphate of lime- - - - - - - 22-00
Phosphate of magnesia and ammonia •> - - 4*50 0-32
53 00 9*80
Valuable as these elaborate analyses are in a scientific point of ^iew, they are quite
unnecessary for practical purposes in ascertaining the value of any giren sample, for
on which of these various constituents does the chief efficacy of guano depend ?
Ammonia. — Undoubtedly one of the moat, if not the most, important constituents of
guano is the ammonia. Authors di£fer as to the precise manner in which ammonia
and its salts act in promoting the growth, and especially in the development of the
nitrogenised compounds of plants ; but the fact is placed beyond dispute, whether it
be that the ammonia contained in the air is decomposed by the leaves, or that the salts
of ammonia are absorbed by the spongioles of the roots in solution in water. Now, it
is quite possible that, in the mysterious economy of the life of the plant, the ammonia
may perform a slightly di£ferent function when in different states of combinatioD,
either with hydrochloric, sulphuric, nitric, phosphoric carbonic, uric, humic, or oxalic
acids ; and although, as a general rule, we should be inelined to yield the palm in point
of utility to the more soluble combinations, yet all experience goes to show that the
value of an ammoniacal manure may be measured chiefly, if not entirely, by the
quantity of that compound present, and is in a great measure independent of its stale
of combination.
Dr. Ure drew a distinction between what he called the actual and potential ammonia,
i. e. between ammonia and ammoniacal salts ready formed, and compounds, sach as
nric acid, which during their decay are gradually converted into ammonia. It appears
that recent guano contains from 3 to 5 per cent of uric acid, whilst the older deposits
contain generally less than 1 per cent. No doubt the guano at the time of its depo-
sition consisted chiefly of uric acid ; and it is this uric acid which has become con-
verted into salts of ammonia ; for the excrements of birds which live chiefly on fish
are found to contain from 50 to 80 per cent of urio acid. It is also an established
truth in agricultural chemistry that a manure which contains bodies capable of gra-
duaUy yielding up any valuable compound, such as ammonia, are more useful than
those which contain that compound ready formed, and in the state of soluble combt-
natiouF, which the first storm of rain may wash away firom the roots of the plants,
where they are required. Nevertheless, admitting the truth of all this, the writer is
of opinion (and he believes this is the general experience of agriculturists) that the
importance of this distinction between actual and potential ammonia has been rather
exaggerated ; and that generally it is enough for all practical purposes, in estimating
the value of a guano, to determine the total quantity of nitrogen present in every form,
and to consider it as representing an equivalent quantity of ammonia ** in esse " or
** in posse."
GUANO;
419
The amoMHt of ammoma corresponding to the total quantity of nitrogen in the
teverai varieties of guano ranges as follows , —
1. reruoian,
(From 9 analyses by Way*) of samples imported in
1847-8
From Mr. Way's analyses of 10 samples imported in
1848-9
From Mr. Way's analyses of 14 samples imported in
1849
Mean
So that the ayerage (^nantity of ammonia, either exist*
ing in, or capable of bemg yielded by genuine Peruvian
guano, may be estimated at about 17 per cent
2. Angamoe guana
Ammonia (actual and potential) from two analyses by
Dr. Ure
So that this variety is slightly richer in ammonia and
nitrogenised compounds than the Peruvian.
3. Ichaboe guano.
Ammonia (actual and potential) from 11 analyses by
Dr. Ure and Mr. Teschemacher - . . -
Showing that this variety, as far as regards nitrogenised
compounds, is fisir inferior to the preceding; and the
same remark applies to the succeeding variedes, e,g,'. —
4. Patagonian guano.
From analyses of 14 samples by Dr. Ure and Mr.
Teschemacher .......
5. SaHdanha Bag guano.
From results of analyses of 9 samples by Mr. Way -
From results of 9 analyses by Dr. Ure and Mr.
Teschemacher -.-.-..
6. Kooria Mooria,
From results of 3 analyses by Mr. Nesbit . . -
From results of 3 analyses by Mr. Apjohn
Maxl-
mum.
18*94
17-81
18-94
Mini,
mum.
Moan.
16-40
15-98
16-82
20-89
9-5
4-68
2*49
2-10
0-34
0*318
20*40
4*5
1-60
0*94
1*25
017
0127
17*67
16*189
n-88
17246
20*64
7-3
254
1-68
1-56
0-25
0-22
So that the average quantity of ammonia in the several varieties is —
Pemvian
Angamos
Ichaboe
« 17 per cent
- 20
- 7
n
Patagonian .
Saldanha Bay
Kooria Mooria
- 2-5 per cent
- 1-5
- 0-25
PotoMh. — Of the two alkalies, potash and soda, the soil usually contains more than
sufficient soda for the supply of vegetation ; it is therefore chiefly potash which it is
necessary 4o add in the form of manure.
Besides, even the best guano always contains a considerable quantity of common
salt, viz. from 1 *0 to 2-5 and even 5 per cent
Mr. Way, in his valuable paper, ** On the Composition and Value of Guano," only
gives the quantity of alkaline salts, not having determined the potash ; but the average
quantity of potash in sen nine guano may be seen by referring to the analyses before
given in detail, and will be found to vary from 3 to 4 per cent
However, in estimating the value of guano the knowledge of the quantity of potash
is by no means of the same importance as of the ammonia, or the phosphoric acid.
Phosphoric acid, — The phosphoric acid is second in importance to no other consti-
tuent than the ammonia ; being essential for the development of the seeds and all those
parts of the vegetable organism, which serve as foods in the production and restoration
of the flesh and bones of animals. It exists in the guano (as is shown by the pre-
ceding detailed analyses) in combination with ammonia, potash, soda, and lime.
In most analyses the quantity of phosphate of lime,ACaO,PO*, is given instead of
phosphoric acid, PO* or 3HO,PO*; but 156 parts of phosphate of lime (3CaO,PO*)
correspond to 72 of phosphoric acid (PO*), or as 13 to 6.
• On the composition and monex value of the different kinds of Guano. By S, Thomai Way, &c»—
** Journal of the Agricultural Society of England,*' p. 202, &c.
EE 2
420
GUANO.
The amount of phosphate of lime in the sereral Tarieties of gnano ii as follows : —
Peruvian,
From analyses of 9 samples hy Way, imported in 1847*8
From Mr. Way's analyses of 10 samples, imported in
1848-9
From Mr. Way's analyses of 14 samples, imported in
1849
Angamos.
From 2 analyses by Dr. Ure . - - - -
Ichaboe.
From 1 1 analyses by Dr. Ure and Mr. Teschemacher •
Patagonicm.
From analyses of 14 samples by Dr. Ure and Mr. Tesche-
macher ---------
Saldanka Bay.
From analyses of 9 samples by Mr. Way - - -
From analyses of 9 samples by Dr. Ure and Mr. Tesche-
macher ---------
Kooria Mooria,
From analyses of 3 samples by Mr. Nesbit - - -
From analyses of 3 samples by Mr. Apjohn . .- -
mum.
34*45
25-30
28*98
22-00
37-00
65-5
60-96
62-5
25-50
28-50
mum.
1946
21*31
21-23
18-50
26-00
29-3
49-01
51-0
2-80
5*84
26-93
23-30
25*13
20^5
31-50
47-4
54-98
56-7
14-15
1717
So that the ayerage quantity of phosphate of lime in the seyeral specimens is
follows : —
Peruvian -
m
- 25*12
Patagonian
- 47-4
Angamos -
w
- 20-25
Saldanha Bay •
- 55-84
Ichaboe -
m
- 81*50
Kooria Mooria -
- 15-66
These facts are very saggestiye as showing how gnano, by exposure to air and
moisture, has the ammoniacal salts washed out, at the same time, as a consequence,
increasing the ratio of phosphates.
Organic Matter . — The amount of organic matter in guano, other than ammoniA and
its salts, is of no great importance in estimating its value as a manure. Not unfre-
quently the amount of organic matter, containing uric acid or ammoniacal salts, is
stated in analyses, as organic matter ** rich in " or ** containing ammonia ; ** but it is
obvious such analyses are nearly worthless, the value of the guano depending es^n-
tially on the quantity of nitrogenj either existing as ammoniacal salts or capable of
being converted into theuL Good guano contains on an average about 50 per cent
of ash (mineral matters) and 50 per cent of combustible (organic) matters.
Sand. — The knowledge of the proportion of sand in a guano is of some importance
as determining its purity or otherwise. It is easy to understand how a deposit like
guano, existing often near the sespshore, and frequently on a sandy soil, should coo-
tain a certain admixture of sand. Some specimens are almost ftee from it, and few
genuine specimens contain more than 1 to 2 per cent. •
Common talL — The presence of common salt in a guano need not surprise us. It
Is doubtless derived from the sea, partly through the medium of the birds thonselves,
and partly from the evaporation of the salt spray continually driven upon the coasts
by the wmd. It is variable in quantity, as we should expect from a knowledge of its
origin, ranging in samples of genuine guano from 1 to 5 per cent. Although common
sail has been shown * to possess a certain power of absorbing ammonia, yet this is
but transient, and the efficacy of guano cannot be said to depend to any extent upon
the sea salt present in it The knowledge of its amount is of great importance, since
the guano is not unfrequently adulterated with salt
Water. — Obviously the larger the amount of water present in g^oano, the smaller
will be the proportion of valuable constituents in a given weight Genuine gnano
contains on an average from 10 to about 20 per cent of water. Many of the salts in
guano are likewise deliquescent, so that it has a tendency to become moist by ex-
posure to the air; and this tenancy to absorb moisture, is an element of value in the
manure, especially in dry seasons.
Calculation of the money value of guano from the resuUa of analyns. — In a most
Important and interesting paper " On the value of artificial manures,"f Mr. Way
• A. B. Nortbcote, on the FuncUoD of Salt in Agriculture, Phil. Mag. s. 179.
t Agricultural Journal, xtI. 633.
GUANO. 421
arrives at certain money valaes for ammonia, phosphoric acid, and the various con-
stituents of ^ano and other manures, hy a comparison with the cost of these several
compounds m their ordinary commercial salts. These numbers will be found most
valuable to the agriculturist in drawing his own conclusions respecting the value of
a guano or other manure from the results of analysis furnished to him by the chemist.
They are as follows : —
£ ■
Ammonia •-•....•56 per ton.
Potash ---31^
Phosphate of lime (Insoluble) .... 7 ^
Phosphate of lime (soluble) ----- 32 „
Organic matter .-...--i^
and the following example of their application may prove useful.
Calculation of the money value of guano, as deduced from the cost of its several
constituents in their commercial salts, applied to the mean composition of
Peruvian guano deduced by Mr. Way from 78 analyses :—
100 tons contain £ £
Ammonia - - - - 1 6*5 at 56 per ton 930
Organic matter • • . 52*0 „ 1 „ 52
Potash ... - 3-5 „ 31 „ 108
Insoluble phosphate of lime - 23*0 » 7 „ 161
Soluble phosphate of lime - - 7 -0 „ 32 „ 224
Value of 100 tons - £1,475
Or per ton - £14 15 0
Hence it is obvious that whilst guano was selling at 11/ per ton, it was more eco-
nomical and convenient to employ it than to make an artificial mixture of its che-
mical constituents ; but now that the price has risen to about 14/. per ton, it becomes
a question whether it will not be possible to produce an artificial compound having
equal value as a manure which will compete in price with the guano.
Impurities and adulterations. — In consequence of the high price of guano the
great demand for it, and the ease with which the unwary farmer may be imposed
upon, guano is adulterated with various substances, and to a great extent Impo-
sitions even have been practised by selling as genuine guano artificial mixtures,
made to look so much like guano that the farmer would scarcely detect it. The
writer recollects examining a guano which contained 50 per cent of sand, and no less
than 25 per cent of sea salt ; and Dr. Ure gives the following analysis of an article
sent to him, which had been offered to the public by advertisement as Peruvian guano
which contained —
Common salt -------- 32*0
Sand 280
Sulphate of iron -------5*2
Phosphate of lime -----.- 4*0
Organic matter (firom bad guano to give it smell) - 23'3
Moisture -------- 7'6
100-0
In fact so numerous and various are the tricks played with guano, that unless a
sample is submitted to a skilful chemist for analysis before purchase, we would
strongly recommend the agriculturist to purchase of no one but dealers of unquestion-
able honour.
Professor Johnstone observes: — "Four vessels recently sailed hence for guano
stations, ballasted with gypsum, or plaster of Paris. This substance is intended for
admixture with guano, and will enable the parties to deliver from the vessel, a nice
looking and light coloured article. The favourite material for adulterating guano
at the present moment, is umber, which is brought fh>m Anglesea in large quantities.
The rate of ad mixture is, we are informed, about 15 cwts. of umber to about 5 cwts^
of Peruvian guano, from which an excellent looking article, called African guano, is
manufactured."
Analysis of Guano.
The following is Dr. lire's method for the complete analysis of guano : —
1. In every case I determine, first of all, the specific g^vity of the guano ; which I
EE 3
422 GUANO.
take by means of spirits of turpentine, with a peculiar instrument contnTed to render
the process easy and precise. If it exceeds 1*75 in density, irater being 1*0, it mast
contain sandy imparities, or has an excess of earthy phosphates, and a defect of axotieed
animal matter.
2. I triturate and digest 200 grains of it with distilled water, filter, dry the in-
soluble matter, and weigh it
3. The above solution, diffused in 2000 gr. measures, is examined as to its specific
gravity, and then with test paper, to see whether it be acid or alkaline.
4. One half of this solution is distilled along with slaked lime in a matrass con-
nected with a small quintuple globe condenser, containing distilled water, and im-
mersed in a basin of the same. As the condensing apparatus terminates in a water-
trap, no part of the ammonia can be lost ; and it is all afterwards estimated by a
peculiar meter, whose indications make manifest one hundredth part of a grain.
5. The other half of the solution is mixed with some nitric acid, and divided into
three equal portions.
a, the first portion, is treated with nitrate of barytes, and the resulting sulphate of
barytes is collected, ignited, and weighed.
6. the second portion, is treated with nitrate of silver, and the resulting chloride of
silver ignited and weighed.
c, the third portion, has a certain measure of a definite soludon of ferric nitrate
mixed with it, and then ammonia in excess. From the weight of the precipitated sab-
phosphate of iron after ignition, the known amount of oxide used being deducted,
the quantity of phosphoric acid in the soluble portion of the guano becomes known.
df the three above portions are now mixed, freed by a few drops of dilute solpharic
and hydrochloric acids from any barytes and silver left in them, and then tested by
nitrate of lime for oxalate of ammonia. The quantity of oxalate of lime obtained
determines that point
6. The last liquor filtered, being freed from any residuary particles of lime by oxalate
of ammonia, is evaporated to dryness and ignited, to obtain the fixed alkaline matter.
This being weighed, is then dissolved in a little water, neutralised with acid, and treated
with soda-chloride of platinum. From the quantity of potash- chloride of platinum,
which precipitates, after being filtered, dried, and weighed, the amount of potash
present is deducted ; the rest is soda. These bases may be assigned to the sulphuric,
hydrochloric, and phosphoric acids, in proportions corresponding to their respective
affinities.
7. The proportion of organic matter in the above solution of guano, is determined
directly by evaporating a certain portion of it to dryness, and igniting. The loss of
weight, minus the ammonia and oxalic acid, represents the amount of organic matter.
8. A second portion of a solution of the guano is evaporated to dryness by a gentle
steam heat weighed, inclosed in a stout well-closed phial along with alcohol of 0-825,
and heated to 212^. After cooling, the alcoholic solution is decanted or filtered clear,
evaporated to dryness by a gentle heat, and weighed. This is urea, which may be
tested by its conversion into carbonate of ammonia, when heated in a test tobe or small
retort. In this way I have obtained from Bolivian guano 5 per cent of urea ; a certain
proof of its entire soundness.
9. Analysis of the insoluble matter. — One third of it is digested with heat in abundance
pf borax-water, containing y|[g of the salt, filtered, and the filter dried by a steam heat
The loss of weight indicates the amount of uric acid, which is verified by supersaturating
the filtrate with acetic or hydrochloric acid, thus precipitating the uric acid, throwing it
upon a filter, drying, and weighing it This weight should nearly agree with the above
loss of weight, the small difference being due to soluble organic matter, sometimes called
geine and ulmic acid. The uric acid is evidenced, 1, by its specific gravity, which I
find to be only I '25, as also that of the urate of ammonia ; 2, by its affording fine purple
murexide when heated in a capsule along with nitric acid, and then exposed to the
vapour of ammonia from a feather held over it ; 3, by its dissipation when heated,
without emitting an empyreumatic odour.
10. Another third of the solid matter is distilled along with half its weight of slaked
lime, and 10 times its weight of water, in the apparatus already described, and the am-
monia obtained from it estimated.
11. The remaining third having been ignited, is digested with a gentle heat in weak
hydrochloric acid, and the undissolved silica and alumina washed on a filter, dried, and
weighed. To the hydrochloric solution, dilute sulphuric acid is added, and the mixture
is heated till all the hydrochloric acid be expelled, with the greater part of the water.
Alcohol of 0*850 is now poured upon the pasty residuum, and the whole, after being
well stirred, is thrown upon a filter. The phosphoric acid passes through, as also the
magnesia in union with sulphuric acid. The sulphate of lime, which is quite insoluble
in spirits of wine, being washed with them, is dned, ignited, and weighoL From the
GUANO. 423
weight ai sulphate of lime, the qtumtitj of phosphate of that earth that was present
becomes known.
la. Ammonia in excess is now added to the filtrate, which throws down the granular
phosphate of ammonia and magnesia. After waging and drying this powder at a heat
of 150^, its weight denotes the quantity of that compound in the guano.
IS. To the filtered liquor (of IS), if a little ammonia be add^ and then muriate
of magnesia be slowly dropped in, phosphate of ammonia and magnesia will precipitate,
from the amount of which the qoantity of phosphoric acid may be estimated
\4. The proportion of oxalate of lime is determined by igniting the washed residuum
(of 9), and placing it in an apparatus for estimating the quantity of carbonic acid given
off in dissolving carbonate of lune. I have rarely obtamed more than ^ gr. of car-
bonic acid from the insoluble residuum of 100 gr. of good guano, and that corresponds
to less than 1^ per cent of oxalate of lime in the guana Sometimes no effervescence
at all is to be perceived in treating the washed residuum with acid after ignition.
15. The carbonate of ammonia in guano is readily determined by filtering the solu-
tion of it in cold water, and neutralising the ammonia with a test or alkalimetrical acid.
16. Besides the above series of operations, the following researches must be made to
complete our knowledge of guana The insolable residuum (of 10), which has been
deprived by two successive operations of its uric acid and ammonia, may contain
aaotised organic matter. It is to be therefore well dried, mixed with 5 times its weight
of the usual mixture of hydrate of soda and quicklime, and subjected to gentle ignition
in a glass or iron tube closed at one end, and connected at the other with an ammonia-
condensing apparatus. The amount of ammonia being estimated by a proper ammonia
meter, represents the quantity of axote, allowing 14 of this element for 17 of ammonia,
being the potential ammonia corresponding to the undefined animal matter. In a sample
of Peruvian guano I obtained 5 per cent of ammonia from this source.
17. The wnole qoantitity of ammonia producible from guano is to be determined by
gently igniting 25 gr. of it well dried, and mixed with 10 times its weight of the
mixture of hydrate of soda and quicklime (2 parts of the latter to 1 of the former).
The ammonia disengaged is condensed and measured, as described above.
18. The ready formed ammonia is in all cases determined by distilling a mixture of
100 gr. of it with 50 gr of slaked lime, condensing the disengaged ammonia, and
estimating it exactly by the meter.
19. The relation of the combustible and volatile to the incombustible and fixed
constituents of guano, is determined by igniting 100 gr. of it in a poised platinum
capsule. The loss of weight denotes the amount of combustible and volatile matter,
including the moisture, which is known fh>m previous experiments.
20. The insoluble matter is digested in hot water, thrown upon a filter, dried, and
vreighed. The loss of weight is due to the fixed alkaline salts, which, after con-
centrating their solutions, are investigated by appropriate tests: 1, nitrate of
baryta for the sulphates ; 2, nitrate of silver for the chlorides and sulphates ; and
3, soda-lime for platinum, for distinguishing the potash from the soda salts.
21. The insoluble matter (of 20) is digested wiUi heat in dilute nitric or hydro-
chloric acid, and the whole thrown upon a filter. The silica which remains on the
filter is washed, ignited, and weighed. The lime, magnesia, and phosphoric acid
may be determined as already pointed out
If, however, the remarks made in an earlier part of this article be correct, it is
altogether unnecessary, in order to ascertain the commercial value of a sample of
guana to perform so elaborate a series of operations as that described above.
The following points are all that are required to be investi^ted : —
The amount of water; organic matter; nitrogen; proportion of ash; analysis of
the ash as to phosphoric acid and alkalies — potash and conunon salt ; sand.
1. Water, — The most delicate and troublesome operation, is perhaps the determina-
tion of the amount of water. If the substance be dried in the water-oven, as is the
usual practice, at 212^ F., a very large quantity of ammonia is expelled : so that it
becomes necessary to desiccate by protracted exposure under a bell ^Uss, over a vessel
of sulphuric acid. Even in this manner, the error is not entirely elmiinated, and Mr.
Way suggests treating the specimen in a shallow platinum dish, with a few drops of
hydrochloric acid, which is allowed to soak through Uie whole : he states, that it may
then be dried at 2129 F., without loss.
2. Orpatue matter. The proportion of organic matter is determined in the usual way,
by burnmg it off in an open platinum crucible, until nothing is left but the white or
brownish white ash, which is then weighed.
3. Determination of nitrogen. — This is best performed by Will and Varrentrapp's
process, which will be found described under the head of Nitrogen.
4. Phoephoric acid, — The phosphoric acid in the ash of the guano is determined by
conversion into perphosphate of iron, and then separation as anmionio-magnesia
ER 4
424 GUANO.
phosphate, in tlie same wa j as has been described under ike head of Ashes €iw
Plants. In fact, under this head irill be found the general method for the gobh^
plete analyses of the ashes of organic bodies, -which, if it be thought desirable, may
be carried out, in extenao, in the case of the ash of guano.
5. ADudie8.—li\i\s is, howeyer, scarcely necessary, so long as the alkalies are deter-
mined to ascertain the amount of the Taluable alkali potash, and the extent of can-
tarn ination vith common salt.
6. Sand. — The quantity of sand is determined by treating a portion of the dried
guano vith hydrochloric acid and vater, till nothing more is dissolred, then igniting
and weighing the residue.
Statistics of the guano trade of Peru. — We extract the following from an article
lately published in the official journal at Lima : — The exportation of guano began in
184 1, under the contract with the house of Messrs. Quiros, Allier, and Co. Up to the
end of 1856, the exportation fhnn the Cincha Islands has been 1,967,079 tons, of
-which 1,626,405 tons were sold, and 28^885 were lost at sea. The stock in hand of
the company was 316,789 tons. The gross proceeds of all these sales eanae to
0100,263,518 ; the charges amounted to 361,008,881, learing net proceeds, $39,254,647;
say at £\ per $5 — ;£7,850,927. In the year 1857 the exportation amounts! to
472,965 tons, which, added to 816,789 tons, left on hand in the preyioas year, giyes
789,754 tons; of these 304,589 tons were sold, and 19,156 were lost at sea, leaving
466,009 tons. The net profit this year was 312,538,016, or at 35 per £l— £2,507,603.
In the first six months of the present year the exportation has been 169,580 tons,
-which, added to those in the hands of the consignees at the closing of 1857, or
466,009 tons, giyes 635,589 tons. One of the most grieyous losses that tbegoyemment
has had to suffer in their exportation of gaano has resulted from losses occasioned in
the loadmg of the yessek. The goyemment estimates at 16 per cent of the guano
exported the losses in putting on board, or by guano thrown oyerboard. To ayoid
this serious loss, which amounts to seyeral hundreds of dollars, the goyemment has
now erected a wharf, where yessels of any tonnage come alongside to load, and by a
railway the guano is brought on board the ships from the deposits. Besides this, in
order that the captidns of yessels should not go to sea with their cargoes of guano in
an unseaworthy state, all yessels after receiying their cargoes, come now to Callao to
undergo a proper suryey. Thus the sea risks are likely to be greatly lessened. By
a decree of the 5th of October, 1856, the house of Messrs. Anthony Gibbs and Son, of
London, was requested to take charge of the guano sales in Spain, hitherto confided to
Messrs. C De Murrick and Co., of the same city, on a commission of fiye and a half
per cent ; but the former house haye giyen prom of the interest they take in the wd-
fare of Peru, and of all those depending on the reyennes of that country, by only ac-
cepting and charging four and a half per cent, affording by this item only to the
republic a considerable increase in the proceeds of the sale of the guano in Spain, the
goyemment has issued a decree of thanks in farour of Messrs. A. Gibbs and Son
for their liberality, and besides for the steps they haye taken to effect a considerable
saying in the warehouse rent and other charges on the guano introduced into Spain.
The change of agents in the United States has also caused considerable saying in the
commission and charges. The President promises to lay before the Congress the
result of the investigation of the inspectors sent to Europe and the United States, which
will proye highly interesting.
The stock of guano up to the end of 1857 appears to haye been 635,589 tons, at £lfi
per ton, representing a capital of £7,627,000. This must inyoWe a lai^ge amount of
interest, to which add warehouse rent, and it will be found that there is great expense
inyolyed in keeping it, to say nothing of the deterioration of the quality.
Guano imported^ 1857 : —
Tons. Computed real raloe.
France 1,538 - - £17,023
Western Coast of Africa (not designated) 2,874 - - 17,234
United States 2,067 - - 8,268
Mexico ...... 2,366 - - 11,830
Brazil 914 -- 4,570
Uruguay -.---- 307 - - 1,842
Chili 6,005 - - 78,065
Peru 264,230 - - 3,434,990
Patagonia - 1,312 - - 5,248
British possessions in South Africa - 4,475 - - 22,375
British West India Islands - - - 1,912 - - 9,560
Other parts 362 •- 2,069
288.362 £3,613,074
GUM RESINS. 425
GUANINE. C^^H'N^C. An organic base found by iTnger in gnano. Gaano
contains about 6 per cent
QUAY A. This frait is a native of the two Indies and the Brazils. There are two
well known yarieties, the Psidium pomifentm, or apple-fruited guaya ; and the P. pyri-
/erumj the pear-fruited yariety. The pulpy fruits of these trees make with sugar ex-
cellent preseryes. Imported as Goaya jelly.
GUINEA PEPPER. Another name for Uie Grains of Paradise.
GUM (Gommet Fr. ; Gummi, PflanzeMcMeim, Germ.) is the name of a proximate
vegetable product, which forms with water a slimy solution, but is insoluble in
alcohol, ether, and oils \ it is converted by strong sulphuric acid into oxalic and mucic
acids.
There are six varieties of gum : 1, gam arabic ; 2, gum senega! ; 9, gum of the
cherry and other stone fruit trees ; 4, gum tragacanth ; 5, gum of Bassora ; 6, the
gum of seeds and roots. The first five spontaneously flow from the branches and
trunks of their trees, and sometimes fVom the fruits in the form of a mucilage which
dries and hardens in the air. The sixth kind is extracted by boiling water. In com-
merce, under the name of gum, very different substances are confounded ; thus we
have gum elemi and gum eopal^ which are true resins ; and gum ammoniticum, which is
a gum resin ; and gum elastic (caoutchouc), which is a peculiar body, differing from
eiUier.
Gum arabic and gum Senegal consist almost wholly of the purest gum called
arabine by the French chemists ; our native fruit trees contain some ceranne^ along
with arabine; the gum of Bassora and gum tragacanth consist of arabine and
bassorine.
Gum arabic^ flows from the Acacia arahica, and the Acacia vera, which grow upon
the banks of the Nile and in Arabia. It occurs in commerce in the form of small
pieces, rounded upon one side and hollow upon the other. It is transparent, without
smell, brittle, easy to pulverise, sometimes colourless, sometimes with a yellow or
brownish tint It may be bleached by exposure to the air and the sunbeams, at the
temperature of boiling water. Its specific gravity is 1 '355. Moistened gum arabic
reddens litmus paper, owing to the presence of a little supermalate of lime, which may
be removed by boiling alcohol ; it shows also traces of the chlorides of potassium
and calcium, and the acetate of potash. 100 parts of good gum contain 70*40 of
arabine, 17*60 of water, with a few per cents, of saline and earthy matters. Gum
arabic is used in medicine, as also to give lustre to crapes and other silk stuffs.
Gum Senegal, is collected by the negroes during the month of November, from the
Acacia Senegal^ a tree 18 or 20 feet high. It comes to us in pieces about the size of a
partridge's egg, but sometimes larger, with a hollow centre. Its specific gravity is
1*436. It consists of 81*10 arabine ; 16*10 water; and from 2 to 3 of saline matters.
The chemical properties and uses of this gum are the same as those of gum arabic
It is much employed in calico-printing.
Charry-tree gum, consists of 52*10 arabine ; 34*90 ceraslne ; 12 water ; and 1 saline
matter.
Gum iragaeanthj is gathered about the end of June, from the Astraaalus tragacantha
of Crete and the surrounding islands. It has the appearance of twisted ribands ; is
white or reddish ; nearly opaque, and a little ductile. It is difficult to pulverise
"without heating the mortar. Its specific gravity is 1 '384. When plunged in water,
it dissolves in part, swells considerably, and forms a very thick mucilage. 100 parts
of it consist of 53'SO arabine; 33*30 bassorine and starch; 110 water; and from
2 to 3 parts of saline matters. It is employed in calico printing, and by shoe-
makers.
Gum of Bassora ; see Bassobine.
Gum of seeds, as linseed, consists of 52*70 arabine ; 28*9 of an insoluble matter ;
10*3 water ; and 7*11 saline matter. Neither bassorine nor cerasine seems to be pre-
sent in seeds and roots. For British Gum, see Dextrine.
GUM ELASTIC. See Caoutchouc.
GUM LAC. See Lac.
GUM RESINS. (^Gomme-resines, "Ft. ; Schleimharze, Germ.) "When incisions are
made in the stems, branches, and roots of certain plants, a milky juice exudes, which
gradually hardens in the air ; and appears to be formed of resin and essential oil, held
suspended in water charged with gum, and sometimes with other vegetable matters,
such as caoutchouc, bassorine, starch, wax, and several saline matters. The said con-
crete juice is called a gum-resin ; an improper name, as it gives a false idea of the
nature of the substance. They are all solid ; heavier than water ; in general opaque
and brittle ; may have an acrid taste, and a strong smell ; their colour is very vari-
able. They are partially soluble in water, and also in alcohol ; and the solution in
the former liquid sddom becomes transparent. Almost all the gum resins are medi-
426 GUN COTTON.
oinal snbstancet, and little employed in the arts and mana&ctares. The (allowing is m
list of them : — assafoetida ; gum ammoniac; bdelliom; euphorbiom ; galbanmn ; gam-
boge; myrrh; oUbanum or frankincense ; opoponaz ; and scammony. Snch of these
as are employed in the arts or manniaetarea are described in this work under their
peculiar names.
GUM- WOOD. EucalpyUu piperita^ or bine gum tree of New South Walesi The
wood is sent oyer in large logs and planks ; the colour of dark Spanish mahogaoy,
with a blae and sometimes a greyish cast
GUN BARRELS. See Fibe Abhs.
GUN COTTON. (Syn. F^roxHine; FvlmieoUm, Fr.) In 1833 M. Bracoonot dis-
covered that starch, by the action of monohydrated nitric acid, became converted into a
peculiar substance which dissolved in excess of the acid, and was reprecipitated in a
granular state on the addition of water. This substance, known as zyloidine, when
washed and dried, was found to explode on contact of a light, and even if heated to
356^. It also exploded if subjected to a smart blow. The subsequent researches of
M. Pelooze indicated this singular body to be starch, CH'H)**, in which one equi-
▼alent of hydrogen is replaced by peroxide of nitrogen, or hyponitric acid. The
formula of xyloidine would consequently be -^tq^ > O'*. On the sapposition of this
being the correct formula, 100 parts of starch should yield 127*7 of xyloidine, and
M. Pelooze obtained from 128 to ISO. About thirteen years subsequently to the dis-
covery of xyloidine, M. Schonbein announced his discovery of gun cotton. Chemists
immediately saw the analogy between the two substances, for while xyloidine a|>-
pears to be derived from starch by the substitution of one equivalent of hyponitrie
acid for one of hydrogen, gun cotton is derived from cellulose (C"U'*0'*, isomeric
with starch) by the substitution of two or three equivalents of hyponitric acid for the
same number of equivalents of hydrogen.
Preparation. — Gun cotton can be prepared in several ways. The most simple
consists in immersing, for a few seconds, well carded cotton in a mixture of eqnal
parts by volume of oil of vitriol of the specific gravity 1*845, and nitrie acid of the
specific gravity 1 *500. The cotton when well saturated is to be removed, and, after
being squeezed to repel as much as possible of the excess of adhering acid, well
washed in clean cold water. As soon as the water no longer reddens litmus paper,
the washing may be considered sufficient The gun cotton thus prepared is cautioosly
dried at a heat not exceeding 212°. It is safer to dry at about 150°. The cotton
prepared by this means explodes well, but does not always dissolve easily in ether.
If, consequently, it is desired to prepare a very soluble cotton for photographic collodion,
the following process may be employed, in which, instead of nitric acid,dry nitre is used.
4} ounces pure dry nitre in fine powder.
SO drams (fluid measure) sulphuric acid, sp^ gr. 1*845.
120 grains of well carded cotton.
The cotton is to be well pulled out and immersed in the mixture of ihe nitre and
sulphuric acid. The contact with the acid, &c., is to be insured by stirring and pulling
out the cotton with two glass rods. As soon as perfect saturation is effected, which,
with good management, will be in about one minute, the cotton is to be thrown into
a large pan of water and well rinsed. The vessel is to be continued under a tap
until litmus paper is no longer reddened. The cotton is to be squeezed in the folds
of a clean towel and exposed (after being again well pulled out) to a gentle heat to
dry. It is curious that the most soluble cotton is often the least explosive, although
there is reason to believe that the most soluble cotton is that which nearest approaches
in constitution to tri-nitro cellulose.
M. Schonbein recommends a mixture of one measure of nitric acid with three
measures of sulphuric acid as the best bath for the cotton. The liquid is to be allowed
to cool previous to its immersion. He also saturates the cotton with nitrate of potash,
by immersing it in a solution of that salt before drying. Cotton prepared in this
manner is not adapted for photographic purposes, but it is highly explosive, and
therefore well fitted for blasting rocks.
The true constitution of gun cotton is by no means well established. It appears
to be very liable to differ in composition according to the method of preparation.
According to M. Bechamp it is essential, in order to obtain a cotton both fulminating
and soluble in ether, to operate upon the mixture of nitre and sulphuric acid before
the temperature (which rises on the ingredients being mingled) has fallen. If cooling
has taken place previous to the immersion of the cotton, the resulting pyroxiline is
fulminating, but insoluble in ether.
The analyses of MM. Domonte and Menard, and also of M. Bechamp^ agree best
with bi-nitro cellulose, while those of Gladstone, Yankerchoff, and Reuter, Schmidt and
GUNNERY. 427
Hecker and Pelonse are more in accordance vith atri-nitro cellulose. To add to the
difficulty of forming a conclusion on the subject, M. Peligot's analyses agree best with
the expression /ijq4\s r O*^ which is that of bi-nitro glucose.
According to M. Bcchamp zyloidine and pyroxiline are acted on bj protacetate of
iron, the original substance being regenerated. Thus xyloidine affords starch, and
pyroxiline cotton. The regenerated cotton was analysed with the following result : —
Bxperim«nt. Calculation.
Carbon - « 43-35 C"«7a 44-44
Bydrogen - 6 31 H>* 10 617
Oxygen - -50 84 O'* 80 49-39
10000 162 100-00
B^hamp (and others) regard gun cotton as containing nitric acid. The former
supports his views with namerous experiments, but there are sereral disturbing
influences preventing the products of the decomposition of gun cotton by alkalies, &c.
being regarded as sufficiently known to enable us to express a decided opinion as
to its true constitution. It may be mentioned in e'vidence of this that daring the
action of caustic potash upon gun cotton, M. Bechamp observed sugar to be pro-
duced. The btter chemist in common with many others doubles the formala which
we, following M. Gerhardt, have provisionally adopted for cellulose ; he moreover
formulates the latter substance and its nitro-derivatives thus : —
C»«H"0",5NO».2HO«pentanitric cellulose.
C«H'"0'*,4N0», HO«tetranitric ceUulose.
C«H»'0»',3NO»=trinitric cellulose.
C»'H»0"«cellulose.
Explosive substances analogous to gun cotton nuiy be prepared from many organic
bodies of the cellulose kind, by immersing them in the same bath as for gun cotton.
Among these may be mentioned paper, tow, sawdust, and calico.
When collodion is wanted for an application to cut surfaces, and the cotton is with
difficulty soluble in alcoholic ether, a solution may easily be obtained if the cotton be
first moistened with acetic ether and the alcoholic ether be afterwards added.
Several of the nitro-derivatives of starch and cellulose undergo spontaneous de-
composition when kept for some time in stoppered bottles (GW^tone).— C. G. W.
GUNNERT. Under the heads of Artiixebt and Fi&babms, we have included
nearly every point with which it appears necessary to deal in a work of this
description. It is convenient, however, to. say a few words in this place of Sir
'William Armstrong's gun. Instead of being cast like ordinary cannon — or formed
of several longitudinal pieces like the Whitworth cannon— or of a hooped or wire-
bound tube, as proposed by Captain Blakely, Mr. Mallet, and others ; the new gun is
formed of an internal steel tube, bound over with strips of rolled iron, laid on spirally,
somewhat after ihe fashion of small- arm barrels, the alternate strips being laid in
opposite directions, so that the joints may cross each other, or, in other words, so as
to ** break joint" This system of construction is, of course, expensive, but it gives
great strength with a very small quantity of metal. The internal steel tube is rifled
m a very peculiar manner. Instead of having two, three, or four grooves, like
ordinary rifled guns — or being formed with an oval bore like that employed by
Mr. Lancaster, or with a polygonal bore, as in the Whitworth system — it has a very
large number of small grooves close to each other, no less than 40, we believe, in a
gun of 2} inches* bore. The shot or shell Mr. Armstrong usualljr makes of cast-iron,
of about three diameters in length, and covers it entirely over with thin lead, so that
it may readily conform itself to the rifled interior of the bore when forced forward by
the explosion of the charge. Provision for loading the gun at the breech is made by
cutting a slot near the breech end down from the upper side into the bore, of a
sufficient length to admit the elongated projectile and the charge of powder, and of a
breadth slightly greater than the diameter of the bore. "Die bore itself is also
slightly enlu-ged where it opens into the space formed by cutting out the slot, in order
that the projectile and powder, after being lowered into the slot, may be easily
pressed forward by hand or other means into the bore. In order to close the space
formed by the slot after the gun is charged, a movable breech-piece is formed to fit
into it, and is famished with two handles, by means of which it may be lifted out or
dropped into its place as required. This breech-piece has fitted to its fh>nt face a
facet of copper, a portion of which projects slightly, so as to form a disc which, when
the breech-piece is forced a little forward, will enter the bore behind the charge, and
by its expansion, at the moment of explosion prevent all escape of gas. The slight
428 GUNPOWDER-
forcing forward of the breech-piece is effected by- means of a strong screw passing in
through the extreme breech end of the gun, and pressing against the rear end of the
breech-piece. This screw is turned by a hand lever. The fore end of the breech-
piece is bored out at the centre, the bore extending through the copper disc, and into
this bore is placed at the time of loading a small discharging cartridge. The ** toach-
hole,** or hole for the detonating plug, is formed in the breech-piece, passing down
from its upper side into its bore ; so that when the piece is to be dischar^:ed the
detonating cap or plug is struck, the small discharging cartridge is thereby fired, and
its fire is instantaneously communicated to the main cartridge in the bore of the gnn
itself. With his shells Mr. Armstrong uses a percussion fuse of his invention for
causing the shell to burst on striking an object, in case the striking takes place before
the time-fuse has operated. In a cylindrical case within the shell Mr. Armstrong
fixes a weight or striker, by means of a pin passing through it and the sides of the
case. This pin is cut or broken by the shock which the projectile receives in the gon
at the instance of firing, and the striker being thus liberated recedes to the rear end
of the case, and there remains until the velocity of the shell is checked by coming
into contact with some object When this takes place, the striker, not participating
in the retardation of the shell, advances in the case, and causes a patch of detonating
composition to be carried suddenly against a fixed poiDt, which fires the composition
and ignites the bursting charge in the shell.
Experiments have shown that a 32-pounder gun, coDstructed upon Mr. Armstrong's
system, has a greater range and fires with greater accuracy than any gun at present
in use in the navy; and yet, while the former weighs but 26 cwt, the present weighs no
less than 95 cwt We may therefore at once reduce the weight of our naval guns
by nearly three-fourths, without impairing their range or aim. This would enoi^
mously increase the facility of handling them, and therefore leave us free to greatly
reduce the number of men employed to work them. Again, with the breech-loading
arm it would probably be found possible to get rid of the running out and in of the
gun while in action, by counteracting; the recoil in some suitable way ; and for this
reason, also the number of men required to work them might be very much below the
present staff. Again, both the bore and the thickness of the metal of the gun being
greatly reduced, the external diameter of the gun will be so small that very small
ports only would be necessary, and this would add materially to the safetj of the
gunners, especially in close action. Another advantage might be gained in the use of
certain guns, particularly the bow-chase guns, on board ship. It is always a matter
of great difficulty to give such a form to the ship that the muzzles of these maj, when
the guns are run out, project sufficiently far to carry the fire of the explosion clear of
the vessel. With the long, slight Armstrong gun this difficulty would not be ex-
perienced. See Shells.
GUNNY CLOTH or BAGS. The coarse sacking made in India, which is n^d
for wrapping rice, spices, &c. The Bengal gunny cloth is made of the fibre of a species
of Corchonu, while that of Bombay and Madras is manu^Eictured from different kinds
of sunn> fibre, the Crotolaria juncea Simmonds.
GUNPOWDER The discovery of gunpowder has been claimed for Roger Bacon
and Schwartz. The ground for this appears to be no more than this. In their
writings the earliest recorded mention of the discovery is made in any European lan-
guage. Roger Bacon, unquestionably antecedent to his German rival, was bom 1214
and died 1292 ; and his work, **De Nullitate Magis," appears to have been written
about 1270, while Kircher*8 account gives 1354 as the date of the discoveryby Schwartz.
It appears, however, that an Arabic manuscript exists in the collection of the Escnrial
which unmistakably describes gunpowder and its properties, the date of which is an-
terior to 1250.— Mallet
This well known composition is employed for charging the numerous varieties of
fire arms. Its use depends upon the fact that, at the moment of ignition, violent
deflagration takes place, accompanied by the evolution of a large volume of gas. It is
evident that if the explosion occurs in a limited space, a vast pressure accumulates
and becomes a propulsive force. The gas produced by the explosion of good gun-
powder occupies nearly 900 times the volume of the powder itself; but, owing to the
high temperature, the space occupied by the gas at the moment of formation, is pro-
bably nearly 2700 times greater than the volume of the powder. One of the most
popular errors regarding the projectile force of explosive substances, arises from the
extremely vague meaning generally attached to the words strong, powerful, and other
equivalent terms. It is this which leads so many to imagine the possibility of attain-
ing marvellously long ranges by means of the various fulminating substances known
to chemists. The latter are uidit for use in firearms, owing to a variety of circam-
stances. One of them is the extreme rapidity of their explosion. The whole mass ap-
pears to be converted into gas at once, whereas in gunpowder the ignition proceeds from
GUNPOWDER. 429
particle to particle. The action of fulminates is also too local ; if a portion of any of
the more violently ezplosivo substances be fired on a piece of metal, the latter -will be
perforated or depressed exactly at the spot occupied by the substance, aud if it be
attempted to use it to charge firearms, they vill be destroyed, and yet, in all proba-
bility the bullet not projected. Moreover, it is impossible to use fUlminates success-
fully for charging shells, because the latter, instead of being blown into pieces of
moderate size, capable of inflicting large wounds and throwing down buildings,
become converted into fragments so small as to be fkr less destructive. The escape
of the Emperor of the French, from a recent attempt at his assassination, was pro-
bably owing to this circumstance.
It has been found that no composition fulfils so many requisites for charnng fire-
arms as a mixture, in due proportions, of sulphur, nitre, and charcoal. It is this
cotnposition which, in the form of small grains, more or less polished, constitutes gun-
powder. The latter should possess several properties which, idthough sometunes
tending in opposite directions, are not entirely incompatible, and may therefore be
nearly attained in practice. Some of the principal of these are the following : —
1. The proportions should be so adjusted that the combustion may be complete, and
little residue be left after explosion. 2. The powder should be as little hygrometrio
as possible. 3. It should be sufficiently, but not too explosive. 4. It should be hard
and dense enough to bear carriage without breakage of the grains.
Too great a proportion of carbon and sulphur will cause rapid fouling of the gun,
and the explosive force will be less than it should be ; too small a proportion of
sulphur will render the powder too hygrometric. The presence of soda or chloride
of potassium in the nitre will lead to the same fault The powder must be sufficiently
atamped, or it will not possess the fourth requisite.
The history of gunpowder may be conveniently studied nnder the following
heads: —
Preparation of the ingredients.
Mixture and granulation.
Modes of estimating projectile force.
Analysis of gunpowder.
Preparation of the Ingredients.
Preparation of the nitre. — The nitre employed for powder is always in a state of
almost absolute purity, especially as regards the presence of the chlorides of potassium
or sodium. The crude nitre of commerce contains several impurities, among which
are found nitrates of soda and lime, chlorides of potassium and sodium, and sulphates
of potash and soda. They are all removed by crystallisation. The principal
impurity is common salt The process of purification is founded on the fact
that, the latter substance is almost equally soluble in hot or cold water, whereas
nitre is far niore soluble in hot than in cold water. The following is the French
mode of refining saltpetre: — 1200 kilogrammes are gently heated with 600 litres
of water in a copper boiler. The solution is constantly stirred and skimmed, and
more nitre is added, until the total quantity is 3000 kilogrammes. As soon as
the whole is added, and it is presumed that all the nitre is dissolved, the com-
mon salt is removed from the bottom of the boiler. The solution is now to be
clarified with glue. For this purpose 400 litres of water are added by small portions,
and then 1 kilogramme of the glue dissolved in hot water. The scum, which soon
rises, is remov^, and the fiuid is boiled until clear. The whole is then allowed to
cool to about 194°, and the solution of nitre is carefully decanted fh>m the layer of
common salt into the crystallising vessel. The latter is a large shallow pan with
sloping sides. The fiuid is constantly stirred as it cools, in order that the crystals
formed may be very small, this is done in order to facilitate the washing process, and
also because the fine powdery crystals are well adapted for admixture with the other
ingredients. When the crystallising solution is cold the nitre is removed to boxes
containing false bottoms, pierced wiSi holes. The aperture in the bottom of the box
(below the false bottom) being closed, a saturated solution of pure nitre is poured on
the crystals to dissolve out the chloride of sodium. Being already saturated, it is
evident it cannot dissolve any of the nitre. After remaining two hours in contact
with the nitre, the solution is allowed to run off, and when the dropping has almost
entirely ceased, the process of washing is repeated, substituting pure water for the
solution of nitre. The product is dried at a gentle heat, being constantly stirred to
enable it to retain the pulverulent form. The power (above alluded to) possessed by
a saturated solution of nitre, of dissolving other salts has been taken advantage of in
one of the processes for analysing saltpetre. Some manufacturers fuse the nitre after
it has been purified by crystallisation, this process has several disadvantages, among
others that of necessitating machinery to reduce it again to a pulverulent state.
J
430 GUNPOWDER.
Preparation of the sulphur. — Sulphur may be purified for the gunpowder maker b j
two processes. In the first the crude article is flised in an iron pot, so contriTed that
the fire does not plry direct! j on the bottom, but only round its sides. The lig^bter
impurities are to be removed by skimming, while the heavier sink to the bottom.
The temperature should not be allowed to rise much above 232^, for it then be-
comes sluggish, and at 320° it is so thick as to prevent the impurities from being
removed.
Sulphur may be more readily and economically pnrified by distiUatioa. The
apparatus for the purpose is exceedingly simple in principle; but the process requires
care, and is not entirely free from danger. As it is not intended to obtain the snlphnr
in the state of flowers, the apparatus for condensation is not required to be kept cold ;
ia foct, the still is purposely placed so near to the chamber of condensation, that the
sulphur may be received in the fluid state. There are several points which most'be
attended to in the construction of an apparatus for the distillation of sulphur ; they ttre
as follows : — 1. The crude sulphur must be capable of being iotrodnced, and the
refined product removed easily, without air being, at the same time, permitted to
enter the still or condenser. 2. Free means of egress for the heated air must be
provided. 3. The contrivance for the latter purpose must not allow fresh air to return.
4. The process must be continuous. The still and condenser employed in France for
the purification of crude sulphur fulfils all these conditions. The still is in the form
of a very wide necked tubulated retort, made of cast iron. It is set in brickwork over
a furnace, and opens into a square brick chamber surmounted by a dome. The kuter
has a rather short chimney over it, contaming a valve opening upwards to permit
escape of the heated air, but not allowing anything to return. Over what may be
termed the tubulature of the retort or stiU, is placed an iron pot with a tube commu-
nicating with it. The pot is heated by the same fire that works the still. The crude
sulphur is placed in the pot where it melts, and bv raising a plug, which closes the
tubulature, may be made to enter the stilL The pipe forming the tubulature riaes a
short distance above the bottom of the iron supply pot This is in order that any
heavy mechanical impurities may sink to the bottom, and not enter the still, and
unnecessarily clog it If the pot be always kept full of melted sulphur, and the latter
is permitted to enter by raising the plug, it is evident that no air will find it way into
either the retort or condenser. It is exceedingly important that this should be the
case, because violent explosions are liable to occur if the highly heated vapour of
sulphur comes in contact with an oxidising medium, such as atmospheric air, which
would convert it into sulphurous acid. The melted sulphur which collects on the
floor of the chamber is allowed to flow out when desired, by means of an iron plug
attached to a rod of the same metaL The sulphur is not allowed to run out entirely,
so as to permit air to enter, for the reason stated above. The loss occurring during
the purification is owing partly to oxidation, resulting in the formation of snlphurons
acid, aud partly to the fixed impurities contained in the crude material. See also the
article Sulphur.
Preparation of the charcoal. -^0( the three ingredients of gimpowder, the most im-
portant is generally considered to be the charcoal Unfortunately the woods which are
best adapted for the production of pyroligneous acid, are not fitted for the manufiie-
ture of gunpowder ; the charcoal must, therefore, be prepared specially. The follow-
ing are the essential properties of good charcoal for powder : — 1. It should be light
and porous. 2. It should yield little ashes. 3. It should contain little moisture.
The woods yielding good powder charcoals are black alder, poplar, spindle tree, black
dogwood, and chestnut Uemp stalks are said to yield go<>d charcoal for gunpowder.
The operation of preparing the charcoal naturally divides itself into three processea.
1. The selection of the wood. 2. Preparation of the wood previous to carbonisation.
3. The carbonisation.
In selecting the wood care is to be taken to avoid the old branches, as the charcoal
made firom them would yield too much ashes. The bark is to be rejected for the same
reason. The wood is to be cut into pieces from 4^ feet to 6 feet long. If the branches
used are more than } of an inch in diameter they are to be split If the wood be
too large, great difficulty will be found in uniformly charring it
There are two methods employed in the charring of wood for gunpowder. In
one, the operation is conducted in pits ; but the process more commonly resorted to is
distillation in cylindrical iron retorts. There are certain advantages in the pit pro-
cess, but they are more than counterbalanced by the convenience and economy of
distillation. The stills used are about 6 feet long, and 2 feet 9 inches in diameter.
The ends of the cylinders are closed by iron plates, pierced to admit tubes of the
same metaL Some of the latter are for the introduction during the carbonisation of
sticks of wood, which are capable of being removed to indicate the stage of the de>
composition, while another communicates with the condenser. The more Arecly the
GUNPOWDER. 431
Tolatile matters are allowed to escape the better the qaality of the resulting charcoaL
If care be not taken in this respect, especially as the distillation reaches its close, the
tarry matters become decomposed, and a hard coating of carbon is deposited on the
charcoal, -which greatly lowers its qualttv. The process of baming in pits is consi-
dered to yield a superior coal, owing to the facility with which the gases and Tapours
fly off.
The degree to which the baming or distillation is carried, materially inflnences the
nature of the resulting powder. If the operation be arrested before the charcoal
becomes quite black, so that it may retain a dark-brownish hue, the powder will be
more explosiye than it would be if it were pushed until the charcoal had attained a
deep black colour. When it has been found that no more volatile products are being
given off, the fire is damped, and in a few hours the contents of the cylinders are
transferred to well closed iron boxes to oooL
IflZTUBB ANB OrAMULATIOK.
A very considerable number of methods have been employed at various times, for
effecting that thoroujrii incorporation of the ingredients necessary for the production
of a good powder. The oldest method consists in stamping the materials m wooden
mortars. The pestles are square shafts of wood ending in brass beaters. The
mortars are of wood, and so shaped that any of the composition which may be forced
upwards by the blows of the stampers, falls back to the bottom. In order to prevent
fi^cture of the mortars, a piece of wood of the toughest kind should be let in on the
spot where the pestle faJls. The pestles are raised by means of cogs fixed on a shaft,
driven by a water wheel or steam engine.
One of the many methods adopted to mix the nitre, sulphur, and charcoal, is by
means of drums containing metallic balls ; but this arrangement is inferior to that
where edge stones are employed. This last is superior to all others, the product being
not only very dense and, therefore, capable of enduring, witibout becoming pulverulent,
the motion unavoidable in carrying it about ; but it is also thoroughly incorporated. It
is, of coarse, essential that the stones, and the bed on which they work, should not strike
fire dnriog work. To secure this, they are sometimes made of calcareous stone, and
sometimes of cast iron. Previous to being subjected to the action of the mill, the ingre-
dients must be pulverised and mixed. The pulverisation may conveniently be
effected in wooden drums, containing metallic balls. The pulverised materials, after
being stfled or bolted, and weighed out in the proper jivoportions, are to be inserted
in a mixing drum, containing on its inside pieces of wood projecting inwards, so that,
as it revolves, complete admixture gradually takes place. The product of the last
operation is now ready to be laid on the bed of the mill. Daring the grinding, the
cake is kept moist by the addition, at proper intervals, of enough water to make it
cohere. As the stones revolve, a scraper causes the material to take such a position
that it cannot escape their action. The cake produced by the action of the stones is
ready for graining or coming. For thispurpose the cake is subjected to powerful pres-
sure, by means oi a hydrauhc press. The mass is then broken up and transferred to
a species of sieve of skin or metal pierced with holes. A wooden nail is placed on the
fragments, and the sieves are violently agitated by machinery. By this means the
grains and dust produced by the operation fall through the holes in the skin or metal
discs, and are afterwards separated by sifting. Sometimes the machinery is so arranged
that the graining and separation of the meal powder is effected at one operation.
The meal powder is reworked, so as to convert it into grains. The next operation
to which the powder is subjected is glazing. Its object is to render it less liable to
injury, by absorption of moisture or disintegration during its carriage from place to
place. The glazing is effected by causing the grained powder to rotate for some
time in a wooden drum or cylinder, containing rods of wood running fW>m end to end.
The grains as they rub against each other and against the wooden ribs, have their
angles and asperities rubbed o£^ and at the same time the surface becomes harder and
polished. It is finally dried by exposure to a stream of ur, heated by means of
steam.
A vast number of experiments have been made, at various times, to discover the
proportions of nitre, sulphur, and charcoal best adapted for the production of gunpowder.
It has been found, as might have been anticipated, that no general rule can be given,
no admixture can be made which shall fulfil every requirement Those powders
^hich contain the largest quantities of charcoal are, it is true, as powerful as others
in projectile force ; but they have the disadvantage of attracting more humidity from
the air. It is very singular that all nations appear to have found, by trial, the propor-
tions most generally UMfhl for ordinary purposes, and it is worthy of remark, that
they all approximate to the percentages required by the very simple formula.
432
GUNPOWDER.
KO,NO* + S + 3G. In fact, the Prossian ponder approaches so closely the theo-
retical nambers, that they fiill within the limits of the errors of analysis, duis: —
Prussian powder.
Theoretical proportumi .
Nitre -
Sulphar
Charcoal
- 75-0
- 11-5
- 13-5
1000
KO,NO* 93 or 1 equivalent 74*8
8 - 16 „ „ 11-9
O - 18 or 3 eqoivalents -IS'S
127
100-0
When a powder constituted as above is fired, the decomposition is probably as
follows (represented in symbols) : —
KO,NO» + S + 3C -= 3CO« + N + KS.
That is to say, the explosion of one equivalent of powder results in the formation of
three equivalents of carbonic acid, one of nitrogen, and one of sulphide of potassiimu
It is evident that these theoretical relations are not absolutely the true expression of
the phenomena, because, in the first place, gunpowder is merely a meefaanical mixture,
and not a definite chemical compound ; and, in the next, the charcoal is repre-
sented by the symbol C as if it were pure carbon, whereas, in fiict, even the purest
and best made charcoals contain variable amounts of hydrogen, ashes, and oxygen.
The hydrogen is partly converted into water and partly into hydrosulphuric add
(sulphuretted hydrogen).
The following are the proportions of the ingredients used in various coontriesL
TabU of the Composition of various Gunpowders.
English war powder - - -
Nitre.
Sulphur.
Charcoid.
75
10
15
„ sporting ditto - - -
77
9
14
French war powder - - -
75
12-5
12*5
„ sporting ditto - - -
76-9
9-6
13-5
„ blasting ditto ...
62
20
18
„ „ ditto (another kind)
65
20
15
United States war powder
75
12-5
12-5
Prussian war powder - - -
75
11-5
13-5
Russian ,, » - * - -
73-8
12-6
13*6
Austrian „,,----
75
10
15
Spanish „ >i - " * *
76-5
12-7
10-8
Swedish „ „ -
75
16
9
Chinese »,,»----
75-7
14*4
99
Blasting powders contain less nitre than others, the combustion is therefore less
perfect, and if used for artillery or small arms, not only is the piece very soon ren-
dered foul, but the ball is projected to a much less distance than is required in prac-
tice. In France, where a heavy tax is laid on sporting powders, this difference of
composition prevents the cheap blasting powder £tom being used in fowling pieces.
Modes of estimating the Projectile Force of Gunpowder.
The usual mode of determining the propulsive force of powder is by ascertaining
the distance to which it can throw a ball of known weight. The instrument used
in this country for this purpose consists of an 8-inch mortar charged with 2 ounces of
powder, the balls being in each case of the same size and weight The French use
for the purpose an iron mortar, elevated at an angle of 45^. The mortar is 7*5 inches
in diameter. The ball is of bronze, and is only 0*067 inches smaller than the bore
of the gun ; the windage is, consequently, very smalL The charge of powder being
3*2 ounces, and the weight of the ball 65 lbs., the latter should be thrown not less
than 437 '5 yards.
The force of powder may also be estimated by means of an instrument, called a
pendulum gun. It consists of a gun barrel hung at the lower end of a pendulum, so
arranged that the amount of angular deviation caused by the recoil may be measured;
the balls may also be fired into a cup suspended to a similar pendulum. The data ob-
tained serve to enable the rapidity of motion of the ball, at the moment of discfaaige,
to be calculated by means of formule contrived for the purpose.
GUTTA PERCHA. 433
On TtaB Analysis of Gunpowder.
Several methods have been given by various chemists for the analysis of gnn-
powder : the following, on the whole, appears the most effective : — The percentage of
water is, in the first place, to be determined by drying in vacuo over salphoric acid,
nntil no more dtmination of weight occurs. The dried powder, or a fresh quantity,
is then to be washed on a filter with boiling water, until nothing more is dissolved out.
The residue is to be dried below 212^ and weighed; the loss is the nitre. If pre-
ferred, the solution of the nitre may be evaporated to dryness, and the residue
weighed. The mixture of charcoal and sulphur is then to be digested in a stoppered
flask, with bisulphide of carbon; this will dissolve out the sulphur and leave the
cfaarcoaL The loss of weight of the dry mixture of sulphur and charcoal will enable
the percentages of sulphur and charcoal to be calculated. If it be desired to know
the quality of the charcoal, a combustion of it may be made with a mixture of chro-
mate of l«id and bichromate of potash* Ordinary charcoal contains from 69 to 74 of
carbon, 3*9 to 5*5 hydrogen, 0*5 to 3*0 per cent ashes. It has been attempted to dis-
solve out the sulphur with sulphite of soda or caustic potash ; but these methods in -
Tolve several sources of error.
Good gunpowder should not lose more than 1 per cent of moisture on drying. It
should not leave alkaline globules, when exploded on a clean metallic plate. The
specific gravity of a good powder should not be less than 1*755 ; it is sometimes as
high as 1*840. The denser the powder the better it endures transportation. As the
density cannot be taken in water, owing to the solubility of the nitre, turpentine or
benzole must be substituted, a correction being made for the difference in density of
the fluid medium. — C. G. W.
GUTTA PERCHA Although the trees yielding this substance abound in the
forests of the Indian Archipelago, the first notice tiucen of it appears to have been
by Dr. W. Montgomerie, in a letter to the Bengal Medical Board, in the beginning of
1843, wherein he recommends the substance as Ukely to prove useAil fbr some surgical
purposes, and supposes it to belong to the fig tribe. In April, 1843, the substance was
taken to Europe by Dr. D* Almeida, who presented it to the Royal Society of Arts of
London, but it did not at first attract much attention, as the Society simply acknowledged
the receipt of the gift ; whereas, its value becoming known, they awarded a gold medal
to Dr. W. Montgomerie.
The gutta percha tree, or gutta tuban, as it ought more properly to be calif d«
according to Mr. Oxley, belongs to the natural family Sapoiea, but differs
much fVom all described genera, having alliance with both Aehrcu and BoBsia, but dif-
fering in some essentials from both. It is the Isonandra gutta of Hooker, and is
described in the London Journal of Botany, 1848, where it is figured, and in Pereira's
Materia Medtea^
The tree is of a large size, from 60 to 70 feet in height, and fi^ym 2 to 3 feet in dia-
meter. Its general appearance resembles the genus 7>wrto, or well known Doorian, so
much so as to strike the most superficial observer. The under surface of the leaf, how-
ever, is of a more reddish and decided brown than in the durio, and the shape is some-
what different
Only a short time ago the gutta percha tree was tolerably abundant on the island of
Singapore ; but already all the large timber has been felled, and few, if any, other
than small plants* are now to be found. The range of its growth, however, appears to
be considerable, it being found all up the Malayan Peninsula, as fkr as Fenang. The
tree is also found in Borneo^ and, there is little doubt, is to be found in most of the
islands adjacent
The localities it particularly likes are the alluvial tracts along the foot of hills, where
it flourishes luxuriantly, forming, in many spots, the principal portion of the jungle.'
But, notwithstanding the indigenous character of the tree, its apparent abundance and
wide-spread diffusion, the gutta will soon become a very scarce article, if some more
provident means be not adopted in its collection than those at present in use by the
Malays and Chinese.
Montgomerie says " a magnificent tree of 50, or more probably 100 years* growth,
is cut down, the bark stripped off and the milky juice collected and poured into a
trough formed by the hollow stem of the plantain leaf; it quickly coagulates on ex-
posure to the air ; but from one tree I am told not more than 20lb6. or SOlbs. are
procured."
The mode in which the natives obtain the gutta is by cutting down the trees of
full growth, and ringing the bark at distances of about 12 to 18 inches apart, and
placing a cocoa-nut sheU, spathe of a palm, or such like receptacle, under the fallen
trunk, to receive the milky sap that immediately exudes upon every fresh incision.
This sap is collected in baxnboos, taken to their houses, andboiled, in order to drive off
Vol. II. F F
434 GUTTA PEBCHA.
the watery particles and inspissate it to the consistence it finally assomes. Altlioogh
the process of boiling appears necessary when the gntta is collected in lai^ qoantities,
if a tree be ft-eshly wounded, a small quantity allowed to exude, and it be eolleeted and
moulded in the hand, it will consolidate perfectly in a few minutes, and have all tike
appearance of the prepared article.
When it is quite pure the colour is of a greyish white ; but, as brought to market, it
is more ordinarily found of a reddish hue, arising ttom chips of bark that fed! iato the
sap in the act of making the incisions, and which vield their colour to iL Besides
these accidental chips there is a great dJeal of intentional adulteration by aawdnat and
other materials. Some specimens brought to market do not contain much leaa than
^ lb. of impurities : and even in the purest specimens, one pound of the substance
yielded, on being cleansed, one ounce of impurities. Fortunately, it is not difficolt
to detect or clean the gutta of foreign matter, it being only necessary to boil it in
water until well soften^ roll out the substance into thin sheets, and then pick oat all
impuritie?, which is easily done, as the gutta does not adhere to anything, umI all
foreign matter is merely entangled in its fibres, not incorporated in its snbstaaee.
The quantity of gutta percha obtained from each tree Taries from 5 to 20 catties, so
that, taking the average at 10 catties, which is a tolerably liberal one, it will n?qDire
the destruction of ten trees to produce one picul. How much better would it, rhere>
fore, be to adopt Uie method of tapping the tree, practised by the Burmese in obtaining
the caoutchouc from the Ficus Jaslica (via. to make oblique incisions in the bark,
placing bamboos to receive the sap which runs out freely). True, they would not at
first get so much from a single tree, but the ultimate gain would l^ incalcolmUe,
particularly as the tree seems to be one of slow growth; by no means so rapid as the
Ficus elastica.
Properties of the Gutta percha, — This substance when fresh and pure, is of a dirty
white colour, and of a greasy feel, with a peculiar leathery smelL It is not affected
by boiling alcohol, but dissolves readily in boiling spirits of turpentine, also in naphtha
and coal-tar. A good cement for luting bottles and other purposes is formed by
boiling together equal parts of gutta and coal-tar and resin. When required for ose^
it can always be made plastic by putting the pot containing it over the fire for a Hew
minutes. The gutta percha itself is highly inflanmiable ; a strip cut off takes light,
and burns with a bright flame, emitting sparks, and dropping a black residuum in the
manner of sealing wax, which In its combustion it very much resembles. But the
great peculiarity of this substance, and that which makes it so eminently osefol for
many purposes, is the effect of boiling water upon it When immersed for a few
minutes in water above 150° Fahr. it becomes soft and plastic, so as to be capable of
being moulded to any required shape or form, which it retains upon cooling. If a strip
of it be cut off and plunged into boiling water, it contracts in sixe both in length and
breadth.
It is this plasticity when plunged into boiling water that has allowed of its being
applied to so many useful purposes, and which &st induced some Malays to fabricat«
it into whips, which were brought into Singapore, and led to its further notice. The
natives subsequently extended their manufactures to buckets, basins, and Jogs, shoes,
traces, vessels for cooling wines, and several other domestic uses. Its easy plasticity
and power of retaining any shape given to it when cool, at onoe pointed it oat as
suitable for the manufacture of bougies; and accordingly Dr. W. Montgomeries,
availed himself of this, made several of the above instruments, and recommended the
use of it to the Bengal Medical Board. It also answers very well for the tubes of
syringes, which are always getting out of order in hot climates, when made of
caoutchouc.
Mr. T. Oxley, surgeon. Prince of Wales Island and Malacca, whose remarks are
of much value from his acquaintance with the production of which he writes, says :—
" I observed in the Mechanics* Magazine for March, 1847, a notice of several
patents taken out for the working of this article by Mr. Charles Hancock, in which an
elaborate process is described for cleaning the gutta, as also mention of its having a
disagreeable acid smell The gutta, when pure, is certainly slightly acid, that is, it will
cause a very slight effervescence when put into a solution of soda, but is unaffected
by liquor potass®. The smell, although peculiar, is neither strong nor unpleasant, so
that the article experimented upon must have been exceedingly impure, and possibly
derived a large portion of its acidity from the admixture and fermentation of other
vegetable substances. Again ; it appears to me that, if the gutta be pure, the very
elaborate process described as being necessary for cleaning it, is superfluous. The
gutta can be obtained here in a perfectly pure state by simply boiling it in hut
water until well softened, and then rolling it out into thin sheets, when all
foreign mattor can be easily removed. I woiUd reconunend that the manu&cturers
at home should offer a higher price for the article if previously strained through
GUTTA PERCHA. 436
tclotb at iht time of being collected, vhen thej will receive the gtitta in a itate that will
save them a vast deal more in trouble and expense than the triHing addition necessary
to the original prime cost.**
In February, 1847, Mr. Charles Hancock obtained a patent for improvements
in the manufacture of gutta percha. In the first place, for the construction of a
slicing machine, consisting of a circular iron plate, formed with three radial slots, in
vrhieh knives are fixed in a similar manner to the irons of an ordinary plane or spoke
shave; the shaft which carries the plate is caused to rotate by steam or other power.
The lumps of gutta percha drop against the knives, bv which they are cut into
slices, of a degree of thickness corresponding to the projection given to the knives.
These slices are then soaked in a vessel of hot water till they become pliable. Instead
of a circular revolving cutter, a vertical cutter or chopper may be used ; curved knives
may be had recourse to for refractory lumps. The softened slices are next subjected
to the action of breakers or rollers with serrated blades, which are mounted transversely
over the tank. In front of each breaker there is a pair of fluted feeding rollers ,* and
the pieces of gutta percha are passed to the rollers of the first breaker. There is an
ineluied endless web mounted upon two rollers, the firont one of which is immersed in
the water, and the other is situated opposite the space between the feeding rollers of
the second breaker. There is a second inclined web placed befbre the third breaker.
There is also a mincing cylinder with radial blades working partly in the water.
The feeding-roUers, and the carrying-rollers of the endless webs, are made to revolve
in a forwai^ direction, while the breakers, the mincing cylinder, and the agitator, arc
made to revolve in the opposite direction. The breakers and mincing cylinder should
revolve at the rate of from 600 to 800 revolutions per minute, but the feeding rollers
and endless webs need not move faster than about one-sixth of that rate. Thus, the
substance is reduced to fragments and washed in the water, the heavy impurities falling
to the bottom of the tanks, and the light purer matter floating. The water should
be used cold. When the gutta percha has a fetid smell, it is treated with carbonate of
soda or chloride of lime. The same apparatus may be used for purifying caoutchouc.
Mr. Hancock combined sulphur with gutta percha in the following manner: —He
found that if a minute portion of sulphur be used along with a sulphide the best
result is obtained ; the proper proportions being 6 parts of sulphide of antimony,
or hydrosulphide of lime, and 1 part of sulphur to 48 parts of gutta percha.
When these materials have been mixed, the compound is put into a boiler and heated
under pressure to a temperature of from 260° to 300° F. and it is to be left in this
state for a period varying fh>m half an hour to two hours, according to the thickness
of the materials. He prefers, for efiPecting the union of the sulphurous constituent,
the following method to the masticating machine. 1st He subjects the purified gutta
percha to the combined action of steam and the fumes of orpiment and sulphur mixed
m the proportions stated, in a metal chamber, provided with a steam-tight cover
secured by screw-bolts. There is also a steam boiler connected therewith, and when
the heat in it is raised to about 280^ Fahr., a fire is lighted beneath the pot contain-
ing the sulphurising materials. But the gutta percha, &c., should be heated with the
steam before it is sulphurised. In from half an hour to two hours the sulphurising is
finished. Or, the gutta percha may be rubbed strongly over with the sulphurous
mixture and then heated, either dry or with the aid of steam, or it may be coated in
the form of a paste.
Another of Mr. Hancock's inventions is to expose the gutta percha to the deutoxide
of azote, or chloride of zinc, concentrated and boiling hot, and then washing with an
alkaline solution or mere water. Grutta percha thus treated by the action of nitrous
gas, as it is evolved frcnn nitric acid and copper, iron, or zinc, becomes exceedingly
smooth, and of a lustre approaching to metallic ; the same effect is produced upon
common unsulphurised caoutchouc Gutta percha is thus also freed from all sticki-
ness ; and if sulphurised it acquires under this treatment the downy softness of velvet*
Chloride of zinc and nitrous gas remove the smell of vulcanised caoutchouc in a great
measure, especially if it be afterwards washed.
Another invention is that of masticating gutta percha in the proportion of 6 parts
with 1 of chloride of zinc ; which compound may be afterwards sulphurised. A
fbrther modification consists in producing a spongy gutta percha for stuffing sofas,
&c 48 parts of it moistened with oil of turpentine, coal naphtha, bisulphide of car-
bon, or other proper solvent, 6 parts of hydrosulphide of lime, sulphide of antimony,
or other analogous sulphide, 10 parts of carbonate of ammonia, carbonate of lime, or
other substance that is either volatile or capable of yielding a volatile product, and 1
part of sulphur. Mr. Hancock mixes these materials together in a masticator, and
then subjects them to a high degree of heat, observing the same conditions which
are stated in the former description, except only that me heat may be pushed with
advantage several degrees higher, say from 260° to 800°.
TV 2
436 GUTTA PERCHA.
Varions articles are manufactured of ordinary gutta pereha, sacli as single and
double texture waterproof fabrics, boots, galoshes, belts, bandages, trowsers and other
straps, capes, life-preseryers, tubes, knapsacks, caps, cups, and other vessels of catpncity,
hammer cloths, cotton spinning rollers, backs of cai^ for carding irool, pianoforte
hammers, paper holders, springs, trusses, &c. By taking the gutta pereha after it
has been sulphurised, and brushing it vith a solution of resin in boiling oil (linseed ?X
placing it in a chamber heated to from 75^ to 100° Fahr., and afterwards polishing
it by the means usually empbyed by the japanners, it acquires the lustre of japanned
wares.
Mr. Hancock has also contrived a machine for cutting gutta pereha into strips or
riband, threads, or cord of any required shape. It consists of two grooved rollers of
iron or steel, mounted in a suitable framework. The grooves of each roller are semi-
circular, and the projecting 4^visions between the grooves are made with knife edges,
so as to divide readily any sheet or mass of gutta pereha presented to them. The
nnder roller is flanged at both ends, and the upper roller is made to fit inside of these
flanges, in order to keep the cutting edges ftx>m shifting or being damaged. To cut
thin sheets of gpitta pereha with this machine into strips or ril^nds, the material is
passed through it in a cold state, and only the cutting edges are brought into opera-
tion. To make round cord or thread by means of it, either a sheet of gutta pereha of
a thickness equal to the diameter of the holes formed by the grooves, and at a tem-
perature of 200° Fahr. (produced by supplying it from a feeding- chamber heated to
that degree) is passed through the machine, and the threads or cords are received in
a tank of cold water, from which they are led away to be wound on reels or dmms ;
or the gutta pereha is employed in a plastic state, and passed under a gauge before it
enters the machine. If it be desired to produce a cord of a semicircular form in the
transverse section, a plane roller is substituted for the lower grooved roller ; or should
cord of a square, triangular, or hexangular, or any other form be required, the two
rollers must be shaped to suit
Gutta Pereha Tubes. — A series of interesting experiments have been made at the
Birmiogham Waterworks, relative to the strength of Gutta Pereha Tubing, with a
view to its applicability for the conveyance of water. The experiments were made
(under the direction of Henry Rose, Esq., engineer), upon tubes | of an inch diameter,
and one eighth, of gutta pereha. These were attached to the iron main, and subjected
for two months to a pressure of 200 feet head of water, without being in the slightest
degree deteriorated. In order to ascertain if possible the maximum strength of the
tubes, they were connected with the Water Company's hydraulic proving pump, the
regular load of which is 250 lbs. on the square inch. At this point the tubes were
unaffected, and the pump was worked up to 337 lbs., but to the astonishment of every
one the tubes still remained perfect It was then proposed to work the pump np to
600 lbs., but it was found that the lever of the valve would not bear this weight The
utmost power of the hydraulic pump could not break the tubes.
The gutta pereha being somewhat elastic, allowed the tubes to become slightly ex-
panded by the extraordinary pressure which was applied, but on its withdrawal they
resumed their former size.
This tubing is such an extraordinary conductor of sound, that its value, not only
to deaf persons, but to the public generally, will speedily be appreciated. It has
already been fitted up in dwelling houses, in lieu of bells ; — as speaking tubes for
giving and receiving messages in mines, railway stations, prisons, workhouses, hotels,
and all large establishments, it is invaluable.
Properties of common Gutta Pereha,— -The gutta pereha, purified for mann&ctaring
purposes, is of a reddish-brown colour ; it readily becomes electrical by friction and
IS a bad conductor of both electricity and heat. At the ordinary temperature of our
climate, say from 32° to 77°, it possesses about as much tenacity as thick leather, with
rather less flexibility; it softens and becomes sensibly doughy towards 120°, although
still very tough. Its ductility is such, at a temperature of from 1 10° to 24 1°, that it is
readily extended into thin sheets, or drawn into threads or tubes ; its flexibility and
ductility diminish as the temperature becomes lower. It does not possess at any tem-
perature the peculiar elastic extensibility which characterises caoutchouc Exposed
for an hour to a temperature of 14°, its flexibility is slightly diminished.
In its varions forms, gutta pereha possesses a peculiar porosity, as may be shown
in the following manner : — A drop of its solution in sulphuret of carbon is to be
placed on a glass slip ; the spontaneous evaporation soon reduces this solution to a
whitish plate ; if it be then examined with the microscope, the numerous cavities with
which it is pierced may be distinctly perceived. These cavities may be rendered
still more visible by means of a drop of water ; the liquid gradually insinuates itself,
the mass appears more opaque, and by means of the microscope the cavities are seen
to be enlarged.
GUTTA PERCHA- 437
. Similar results are obtained by keeping thin transparent laminsD,' obtained by the
evaporation, by heat, of a solution of gutta percha immersed in water for & considerable
time.
The preceding observations lead us to think, that this substance retaining, in con-*
sequence of its porosity, a great many minute particles of air, owes to this circum-
stance its appearance of possessing a less density than that of water, namely 0*979.
In fiict, on stretching giitta percha under strong pressure, and immediately cutting
the strips thus produced into very small pieces under water, the greater part of the
fragments fidl to the bottom of the ressel — some immediately, others after absorbing
a certain quantity of water. The same result is also obtained by keeping very thin
leaves of gutta percha, prepared by different methods, immersed for a month in water
deprived of air ; their pores becoming gradually filled wiUi the liquid, they became
heavier than the water, and then ceased to float. Outta percha is also heavier in
proportion to the length of time it has been exposed to the air, particularly in thin
leaves.
The porous structure of gutta percha becomes changed into a fibrous texture when
it is drawn out so as to double its length : then retaining but little extensibility, it
supports, without breaking, the action of a force equal to double that required for its
elongation in the first instance.
Common gutta percha resists cold water, damp, and also the various influences
which excite fermentation ; but it can be softened, and experience a sort of supeiiKcial
doughy fusion by the action of the solar rays in summer.
It is not attacked by alkaline solutions, even when caustic and concentrated ; am*
monia, saline solutions, water containing carbonic acid, the various vegetable and
mineral acids, do not act upon it ; the weaker alcoholic liquors (wines, beer, Stc ) do
not touch it ; and even brandy scarcely dissolves a trace of it. Olive -oil does not ap-
pear to attack gutta percha when cold ; when hot, it dissolves a small portion of it,
which is again precipitated on cooling.
Sulphuric acid with one equiv. of water colours it brown, and disintegrates it with a
sensible evolution of sulphurous acid.
Muriatic acid, in its saturated solution in water at a temperature of 68° F., attacks
gutta percha slowly, and gives it a more or less deep brown colour, at length rendering
it brittle.
Monohydrated nitric acid attacks it rapidly, with effervescence and an abundant evo-
lution of fhmes of hyponitrous acid ; the subistance is decomposed, and coloured of a
brownish-orange red : it becomes doughy, and afterwards solidifies by degrees and re-
mains friablC'
In the cold, and even by heat, only a part of the gutta percha (0*15 to 0*22) is dis«
solved by anhydrous alcohol or ether. Benzine and spirits of turpentine dissolve it
partially when cold, but nearly completely if aided by heat Sulphide of carbon and
chloroform dissolve gutta percha when cold ; the solutions may be filtered beneath a
bell-glass to prevent evaporation ; the filter retains the foreign matters of a reddish-
brown coloar, whilst the solution passes perfectly clear, and almost colourless. The
filtered liquid, exposed to the air in a saucer, allows the solvent to escape, and deposits
the white gutta percha in a plate of greater or less thickness, which shrinks gradually
in proportion to the evaporation of the liquid.
Except the colour, which has disappeared, the gutta percha then offers the characters
and properties mentioned above as belonging to the commercial substance. Submitted
to a gradually raised temperature, it softens and melts, and may be made to boil with-
out acquiring a sensible colour ; the transparent fluid gives abundant vapours, which are
condensible into a nearly colourless oily liquid. The portions last distilled have a
brownish-orange colour, and a thin layer of carbonaceous deposit remains adherent to
the sides of the vessel
AnatysU, — We have said above that alcohol and ether can dissolve only a portion of
gutta percha ; this is because that substance consists, in fhct, of three proximate prin-
ciples, the separation of which has required very delicate observation, although they
are very clearly distinguished by several of their properties.
When gutta percha in thin leaves is brought into contact, in a close vessel, with 15
to 20 vols, of cold anhydrous alcohol, and the temperature raised slowly by means of
the water-bath to the point of ebullition (172° F.), and kept at this point during se-
veral hours, the liquid, if filtered whilst boiling and left in a closed flask, will, at the
end of from 12 to 36 hours, begin to deposit on the sides of the vessel and on Uie sur-
fhce of the solution white opaline granules, distant from one another, but some of them
in groups ; their sise will gradually increase for some days. These granules, carefiilly '
examined under the microscope, will be found to have the form of spherules truncated
by the sides of the vessel. Their surface is either smooth, or bristling with very small
transparent, elongated, lamellar crystals. Some superficial fissures appear to indicate..
FF 3
438 GUTTA PEECHA.
that these sphemles are formed of a aort of transparent yellow kernel coTered
white pellicle.
Perhaps no other example is known of this singular crystalline stmctare. In h^t,
oold anhydrooa alcohol dissolves the whole of the yellow spheroidal snhctanoe, whilst
the superficial pellicle, in the interior of which the alcohol has snhstitated itself Ibr
the solid globule, appears whiter and less transparent.
The alcoholic solution, which has been for some days depositing this complex sphe*
roidal crystallisation, can again take up by heat a portion of the two proximate prin-
ciples remaining in the substance, allowing a fresh quantity to crystallise on cooling
The extraction is completed by returning the IxHling akohol seyend times upon the
gutta percha until it no longer dissolves anything.
The solid substance which has resisted the action of the solvent, poasesses» with
some modifications, the principal properties of crude gutta percha ; we shall here
call it pure gulla. As to the two other organic principles, one is a yeQow resin^ which
is much more soluble in cold alcohol than the other, the while crystalline resitu,
By taking advantage of these different degrees of solubility, we are enabled with
time and patience to effect the complete purification of these three principles. The
separation may also be effected by treating finely^divided gutta percha with cold etfaer»
which dissolves the mixture of the two resins more abundantly than alcohol i they are
afterwards separated from one another by the same treatment already described ibr
alcohol
The tendency of the white resin to form itself into racBated groups is mani-
fested in a rather remarkable circumstance, which it is easy to reproduce. Narrow
ribbons cut from a thin leaf of ordinary gutta percha are to be placed in a tube, and
immersed in anhydrous alcohoL The tube is then closed, and left for twenty or thirty
days, when a few whitish points appear here and there on the ribbons, and afterwards
on the sides of the tube. These points, which become gradually larger, are filmed of
crystalline tufts of the white resin. Thus this proximate principle is separated directly,
and in the cold, even when the atmospheric temperature ia gradually rising, f«r in-
stance during the spring or early summer.
The crystalline white resin, when completely purified by washings with alcohol, and
then redissolved in anhydrous alcohol, is deposited by slow spontaneous evaporation in
the air, in radiated crystals, forming sometimes symmetrical tufts arrangeid in stars,
and then presenting the appearance of a sort of efflorescence.
Distinctive characters and properties of the three proximate principles which am-
stitula common Gutta Percha, — ■ The most abundant of these three principles, forming
at least from 75 to 82 per cent of the whole mass, is the pure gutta, which presents
the principal properties of the commercial substance \ it ia white, transparent at a
temperature of 212^ F., when all ita parts are melted together; opaque or semi-
transparent when cold, from its then acquiring a structure which causes the inter-
position of air, or of a liquid possessing a different refraction from its own. This
structure appears still more distinct than in the natural substance containing all three
principles.
In thin sheets, and at a temperature of 50^ to 68^ F., it is supple, tough, extenaiUe
but not very elastic At 1 12^ F., it softens and turns back upon itself, and becomes
more and more adhesive and translucent in proportion to the devation of temperature,
undergoing a sort of doughy fusion, which becomes more distinct towards 212^ to 230°.
Heat^ beyond this point, it melts, boils, and distils, furnishing a pyrogenous oil and
carburetted gases.
Soubeiran believes the composition of perfectly pure gutta percha to be C**H^ cor-
responding to 87*8 carbon, and 12*2 hydrogen. Faraday found caoutchouc to be
87*2 carbon, 12*8 hydrogen ; hence their chemical e-omposition is identicaL
Pure guttEi, like the other two proximate principles, is quickly rendered electrical
by friction, and is a bad conducter of heat ; it generally floats on water, but sinks to the
bottom as soon as its pores are filled with this liquid. It is insoluble in alc<^ol and
ether, almost completely insoluble in benzine at 32^ F.; it is soluble at 77^ and be-
comes more and more so in proportion as the temperature is raised. The saturated so-
lution at 86° forms itself into a semi-transparent mass when cooled below 32° ; alcohol
precipitates the pure gutta from its solution in benzine.
At 82°, spirits of turpentine dissolves very little gutta, whilst it disintegrates and
dissolves it readily when hot
Chloroform and sulphide of carbon dissolve the gutta percha in the cold.
After the extraction by means of ether of the two resins interposed in the thin
leaves of white gutta percha, leaving the last portion of ether with which they were
impregnated to evaporate in the open air, these leaves, enclosed in a flask, expe-
rienced, after remaining there for two months at a temperature of from 68° to 82° F.,
an alteration which appeared to depend on their porosity, the action of the air, and
GYPSUM. 439
perhaps the ether retained In their pores. However it be, these leaves had then
acquired neir properties : they were brittle : exhaled a very distinct sharp odour ;
brought iato contact with an excess of anhydrous ether, they were partially dissolved;
the soluble portion, obtained by the evaporation of the ether and desiccation at 194^ F.,
iras glatinous and translucent ; it became opaque and hard by cooling down to 14^ F.
Sulphide of carbon, renewed three times in six days, and evaporated each time after
two days' contact, left as residue a white flexible leat The portion not dissolved,
swelled and transparent, did not appear to undergo any diange when left in sulphide>
of carbon for ten daya
This kind of spontaneous transformation would perhaps become complete if more
prolonged ; its study will require much time ; it will perhaps put us in the way of as-
certaining the causes of certain changes observed in some small olgects formed of gntta
pereha. It has already been ascertained, that thin kaves, exposed for eight con-
secutive days to the action of the sun in moist air, were discoloured, and that their sub-
stance had become in great part soluble in ether.
Monohydtated sulphurio add disintegrates, snd communicates a brown colour to the
pure gutta, with evolutioa of sulphurous acid; after eight days' contact, the deep brown
liqntd, on dilution with water, becomes turbid, uid furnishes a brown flocculent preci-
pitate. Nitric acid, with a single eqnivaleBt of water, attacks the pure gutta with a
lively effervescence, snd the evolution of orange vapours of hyponitrous acid. Muriatic
acid, in its saturated solution, slowly attacks the thin leaves of gutta, giving them a deep
brown colour ; at the end of eight days it becomes friable. The reaction of muriatic
acid establishes an additional distinctive character between this proximate principle and
the two others.
M. Payen has carefully examined the chemical and physical peculiarities of the
three principles which he has discovered in gutta pereha. These have, however, no
interest for the manu&cturer, and we refer the chemical student to M. Payen's Memoir.
The juice of Muddar hss been proposed as a substitute for gutta pereha, but we
are not aware that it has in any manufacture taken its place. Dr. Falconer describes
a new kind of gutta pereha, which grows in the most southern British possession of
the Merguin Islands, Indian Ocean.
If a solution of gutta pereha in chloroform be mixed with 3 parts of ether, and ex-
]»08ed for some time to a temperature below 15^, the gutta pereha is precipitated as a
white powder, forming when washed and dried a soft white mass. On spreading this
solution on a plate of glass, a skin is formed, resembling kid-glove leather, which be-
comes transparent on the application of heat These films are beautifully white, if
carefully prepared, and they have been employed in the manufibcture of the finest
kinds of artificial flowers.
In 1848, Dr. Faraday drew the attention of experimentalists to the highly insulating
power of gutta pereha, which not only possesses ^is property under ordinary cir-
cumstances, but likewise retains it under atmospheric conditions which would make
the surface of glass a good eonductor. This has led to its almost universal adoption
as the insulator for the wires of the electrical telegraph. When buried in the earth,
unless it is attacked by insects, or b v a flingus, it retains its high insulatory power,
and we have every reason for believing that gutta pereha does not undergo a change
when immersed in sea water. It has, however, been found, that when it has been
exposed to the intense sunshine of India, it undergoes a remarkable change ; oxygen
is absorbed, the gutta pereha loses its coherence, and at the same time its powers of
insulation.
The quantity of gutta pereha imported in 1857 was —
Cwti. Commitad real value
Holland 4»228- • • - ^23,254
Phillipine Islands ... 263---- 1,446
British East Indies ... 12,087- - . - 66,479
Other parts- . • • . 842- ... 4,631
T. J. P.
OYPSUBiL This natural production, which in its varieties is known as tulphaU of
lime, aiabagter, aeUnite, waHn spar, gypSj and plaster of Paria^ has a composition of,
sulphuric acid, 46*51 ; lime, 32*56 ; water, 20*93.
The amkydriu ftom. Derby is a mineral like gypsum, but, as its name indicates, con-
taining no water; its composition being, lime, 41*2-; sulphurio acid, 58*8 ; this is
also called muriaciu and tripe'ttone. It absorbs moisture and changes to gjpsum.
When gypsum is carefully burnt it loses its water of composition, and forms the weH'
known pkuier of Paris.
The transparent varieties of gypsum are called adenits ; its fine massive varieties
are akUMsUr, and its fibrous kinds satin spar. There is another variety in small
scales of a pearly lustre, known as schaumkatk. See Alabastbb.
FF 4
440 HAIR.
H.
HACKLE. A flax comb. See Flax.
HADE. A miner's term, used in Derbjrshire and some of tlie nortlieni ommtiei^
siffnifying the inclination or deviation from the vertical of any mineral vein or lode.
Hadingt signify that some parts of the vein incline, while others are verticaL
H^MATINONE. a kind of glass used by the ancients for making omameiifal
vessels, mosaics, &c. It is described by Pliny, and has been found pretty abandant] j
in the excavations of PompelL This glass is of a beautiful red colour. It oootains
no tin or any other colouring matter except copper. All attempts of the modems to
imitate the antique futmatinone have hitherto failed ; the nearest approac}i is supposed
to be the Italian porporino, which, however, differs from it in most respects.
HAIR {CheveUf Crvh Fr. ; Hoar, Germ.) is of all animal products the one least
liable to spontaneous change. It can be dissolved in water only at a temperature some-
what above 230° F., in a Papin^s digester, but it appears to be partially decomposed by
this heat, since some sulphuretted hydrogen is disengaged. By dry distillation, hair
gives off sulphuretted gases, while the residuum contains sulphate of lime, common
salt, much silica, with some oxide of iron and manganese. It is a remarkable
fact that fair hair affords magnesia, instead of these latter two oxides. Horse-hair
yields about 12 per cent of phosphate of lime.
We have no recent analysis of hair. Vauquelin found nine different substances in
black hair; in red hair, a red oil instead of a greenish-black one.
Hairs are tubular, their cavities being filled with a fat oil, having the same eokmr
with themselves. Hair plunged in chlorine gas, is immediately decomposed and con-
verted into a viscid mass ; but when immers^ in weak aqueous chlorine, it nndeigoes
no change, except a little bleaching.
Living hairs are rendered black by applying to them for a short time a paste made
by mixing litharge, slaked lime, and bicarbonate of potash, in various proportioos^
according to the shade of colour desired. The ordinary mode of dyeing human hair,
is first to saturate the hair with the sulphide of potassium in solution ; then, when this
has been well absorbed and is partially dry, a solution of nitrate of silver is to be ap-
plied. By varying the proportions of the sulphide, and the strength of the silver
solution, almost any tone of colour, from a brown to a black, can be produced.
Tho salts of silver, mercury, lead, bismuth, as well as their oxides, blacken hair,
or make it of a dark violet, by the formation, most probably, of mettilic sulphurels
(gulphides}.
Hair as an object of manufactures is of two kinds, the turhf and the MtraighL The
former, which is short, is spun into a cord, and boiled in tUs state, to give it the
tortuous springy form. The hairs of rabbits and hares are prepared for the hat-
maker by a process called Micretage, so as to render them fit for felting. The skins
with the hair still upon them are laid upon a table, and with a brushy made from the
bristle of the wild boar, a solution of nitrate of mercury is applied many times in
saccession, till every part of the fur be equally touched, and tiU about two -thirds of
the length of the hairs be moistened. The skins are then placed together to com-
plete the impregnation, and put into a store-room. In drying there is a retraction of
the hairs, and the required curling is produced. The long straight hair is woven into
cloth for sieves, and also for ornamental purposes, as in the damask-hair cloth of chair
bottoms. For this purpose the hair may be dyed in the following way:—
Forty pounds of tail hairr about 26 inches long, are steeped in lime water during
twelve hours. Then a bath is made with a decoction of 20 pounds of logwood, kept
boiling for three hours, after which time the fire is withdrawn from the boiler, and
ten ounces of copperas are introduced, stirred about, and the hair is immersed, hav-
ing been washed from the lime in river water. The hair should remain in this cod-
ing bath for 24 hours, when the operation will be finished. Hair used for weaving
is obtained principally f«^m South America and from Russia. All the black and
grey hair is dyed for the manufiicture of black hair-cloth for covering furniture.
White only can be dyed so as to produce what are called fancy colours, and great care
is required in the process, which however, when well managed, produces good per*
roanent colours.
' The quality of hair-cloth, as well as the brilliancy and permanency of the colours,
depend in a great dejaree on the nature of the warp, which may be either of cotton,
linen, or worsted. Oolotired hair-cloth, which is made at Worcester, Sheffield, and
Paris, has been much used for fitting up the principal cabins of steam vessels, for
covering sofiu and chairs, and for railway carriages.
HAIR BRUSHES. 441
. • The loomf for ireaying hair differ ftrom the common ones, only in the templet and
the shuttle. Two templets of iron most be used to keep the staff equably bat lightly
stretched. These templets, of which one is represented in>S^. 936, are oonstructed in
the shape of flat pincen ; the jaws, c c, ^ j^ 93^
being famished with teeth inside. A screw,
x>, binds the jaws together, and hinders the
selyage from going inwards. Upon the side
cross-beam of the loom, seen in section at i,
a bolt is fixed which carries a nut F at its
end, into which a screwed iron rod e enters,
on one of whose ends is the handle b. The
other extremity of the screw s is adapted
by a washer and pin to the back of the
pincers at the point h, so that by turning the handle to the right or the left, we draw
onwards or push backwards the pincers and the stuff at pleasure. The warp of the
web is made of black linen yam. The weft is of hair, and it is thrown with a long
hooked shuttle, or a long rod, having a catch hook at its end. The length of this
shuttle is about 3 feet ; its breadth half an inch, and its thickness one sUth. It is
made of box- wood. The reed is of polished steel ; the thread warps are conducted
through it in the usual way. The workman passes this shuttle between the hairs of
the warp with one hand, when the shed or shuttle way is opened by the treddles ; a
child placed on one side of the loom presents a hair to the weaver near the selvage,
who catches it with the hook of his shuttle, and by drawing it out passes it through
the warp. The hairs are placed in a bundle on the side where the child stands, in a
chest filled with water to keep them moist, for otherwise they would not have the
suppleness requisite to form a web. Each time that a hair is thrown across, the
batten is driven home twice. The warp is dressed with paste in the usual way. The
hair-cloth, after it is woven, is hot calendered to give it lustre. In the Great Exhi-
bition of 1851, J. Bardoffsky (Russia) exhibited a collection of bowls, dishes, plates,
&c., formed of the hair of the rabbit, hare, and other animals, which were felt^ and
afterwards varnished. They had the appearance of papier mache, and were very light
In 1857 Wt imported — Cwt. Computed real ralue.
Of COW, ox, bull, or elk hair • " 5,913 - • - £27,495
Goat's hair 8,255,010 - - - 393,314
Horsehair 21,389 - - • 119,778
and of manufactures of hair or goat's wool, not made up, and wholly or in part made
up, 233,200/., as entered at computed real value.
HAIR BRUSHES, or PENCILS, for artists.
The ftair brushes are manufactured with coarse hair, as that of the swine, the wild
boar, the dog, &c. and these are usually attached, by binding with cord or by securing
them with a piece of tin plate, to a wooden handle.
The hair pencils are composed of very fine hairs, as those of the sable, the miniver,
the marten, the badger, and the polecat. These are usually mounted in a quill, but
sometimes they are secured as in the former case with tinned iron.
The most essential quality of a good pencil is to form a fine point, so that all the
hairs without exception may be united when they are moistened by laying them upon
the tongue, or drawing them through the lips. When hairs present the form of an
elongated cone in a pencil, their point only can be used. The whole difficulty consists^
after the hairs are cleansed, in arranging them together so that all their points may lie in
the same horizontal plane. We must wash the tails of the animals whose hairs are to be
used, by scouring them in a solution of alum till they be quite free Arom grease, and
then steeping them for 24 hours in luke-warm water. We next squeeze out the water
by pressing them strongly from the root to the tip, in order to lay the hairs as smooth
as possible. They are to be combed in the longitudinal direction, with a very fine-
toothed comb, and finally wrapped up in fine linen, and dried. When perfectly dry,
the hairs are seized with pincers, cut across close to the skin, and arranged in separate
heaps, according to their respective lengths.
^ch of these little heaps is placed separately, one after the other, in small tin pans
with flat bottoms, with ^e tips of the hair upwards. On striking the bottom of the pan
slightly upon a table, the hairs get arranged parallel to each other, and their delicate
points rise more or less according to their lengths. The longer ones are to be picked
out and made into so many separate parcels, whereby each parcel may be composed of
equally lon^ hairs. The perfection of the pencil depends upon this equality ; the
tapering point being produced simply by the attenuation of the tips.
A pinch of one of these parcels is then taken, of a thickness corresponding to the
intended size of the pencil ; it is set in a little tin pan, with its tips undermost, and
442 HARDENING.
isshaken by ttrikmg the pan on the table as before. The root end of the haira b^a^
tied by the fisherman's or Beaman's knot, with a fine thread, it is taken oat of the pan,
and tiien hooped with stronger thread or twine ; the knots bdng drawn rery tight by
means of two little sticks. The distance from the tips at which these Hgntnres are
placed, is of coarse relative to the nature of the hair, and the desired length of the
pencil. The base of the pencil must be trimmed flat with a pair of seiawr^
Nothing now remains to be done but to mount the pencils in qoill or tin-plate tabes,
as above described. The quills are those of swans, geese, docks, lapwings, pigeons,
or larks, accordiog to the size of the pencil. They are steeped daring 24 hoars in
water, to swell and soften them, and to prevent the chance of their splitting when the
hair brush is pressed into them. The brush of hair is introdoced by its tips into the
large end of the cut quill, having previously drawn them to a point with the lips, when
it is poshed forwards with a wire of the same diameter, till it comes out at the other
and narrower end of the quiU.
The smaller the pencils^ the finer ought the hairs to be. In this respect, the mana-
fiujture requires much delicacy of tact and experience.
HALIOTIS, the sea ear ahelL A genus of molluscous animals belonging to the
class Gasteropoda. These shells, possessing a fine nacre, are extensively osed in the
ornamentation of papier mache articles, and mother-of-pearl ornaments.
HALOGENE, is a term employed by Berzelius to designate those substanees which
form compounds of a saline nature by their onion with metals ; sach are chlorine,
iodine, bromine, fluorine, and cyanogen ; the salts thus formed being called hahid
sails, from their resemblance to common salt (NaCl), (2a*, sea salt, and dSof, IbnnX
Since the discovery of the compound halogene. Cyanogen, some chemists have
been led to view all salts as under the type of haloid salts ; assuming in the different
acids certain compound halogens, as in sulphuric acid the halogene (SC) ; in nitric
acid the halogene (NO*) &c. ; which in combination with hydrogen form the acids;
the different Sidts being formed by the displacement of the hydrogen by the metal,
as foUows : sulphuric acid (HSO<), sulphate of potash (KSCH), nitric acid (HNO*),
nitrate of soda (NaNO*), &C--H. K. B.
HANDSPIKE. A strong wooden bar, used as a lever to move the windlass and
capstan io heaving the anchor, or raising any heavy weights aboard ship. The
handle is round, smooth, and somewhat taper. The other end is squared to fit the
holes in the head of the capstan or the barrel of the windlass.
HARDENING. The processes by which metals are rendered harder than they
are when they first leave the hands of the workman.
Some metals are hardened by hammering or rolling ; but care is required not to
carry this too far, as brittleness may be induced. Sadden cooling is had recourse to
with some metals. Pure hammered iron appears after annealing to be equally soft,
whether suddenly or slowly cooled ; some of the impure kinds of malleable iron harden
by immersion. Steel, however, receives by sudden cooling that extreme degree of
hardness combined with tenacity, which places it so incalculably beyond every other
material for the manufacture of cutting tools.
In hardening and tempering steel there are three things to be considered, namely,
the means of heating the objects to redness, the means of cooling the same, and the
means of applying Sui heat for tempering^ or ** letting them down." It is not possible
in this work to enter into the manipulatory details of hardening steel for various pur*
poses ; the most valuable information on this sulgect is given in Holtzapfiel's work on
Turning and Mechanical Manipulation,
Steel pens are hardened by being heated in large quantities in iron trays within a
furnace, and then plunged in an oily mixture ; generally, they are likewise tempered
in oil, or a composition, the boiling point of which is the same as the temperature suited
to " letting them down."
Saws and springs are hardened in various compositions of oil, suet, wax, and other
ingredients, " which however lose their hardening property after a few weeks* constant
use." Steel plates are hardened occasionally by allowing water to fall on them when
hot See Transfer Enorayino.
Case hardening is the process by which wrought iron is first converted exteriorly
into steel, and is subsequently hardened to that particuUr depth, leaving the central
parts in their original condition of soft and fibrous iron. The principal agents osed
for case hardening are animal matters, as the hoofb, horns, bones, and skins of animals.
The prussiate of potash, which is a compound of carbon and nitrogen, is also employed
for case hardening. In principle it is the same as the animal substances. The iron
is heated in the open Srt to a dull red, and the prussiate is either sprinkled upon it or
rubbed on in the lump ; it is returned to the fire for a few minutes, and immersed in
water. In the volume of Lardner*s ** Cyclopsedia," on Iron and Steel, edited by Bobert
Hunt, the subjects of hardening and tempering are treated in a practical manner.
HAT MANUFACTURE.
443
HARBNESa (Dttref^ Fr. ; Hirte> FetHgktit, Gem.) A bard body will acratch
OD€ that is softer tbiui itsell This method of determining the hardness of minerals is
employed by mineralqpsts. A 0O«d steel file is also nsed for trying the respective
lianinefls of minerals.
Mohs introdaeed a scale of hardneig» Yhioh shows the gradual increase in hardnesa
through 10 minerals.
1. Tale } common laminated light green Tariety.
3. Gypntm ; crystallised variety.
3. Odeitei transparent yarietj^.
4. Flwortpcar; ei^stalline variety.
5. Apaiitt; transparent variety.
6. .Fttiipar (orthodase) ; white deavable Tariety.
7. Quartz; transparent.
8. Topaz; ditto.
9. Sapphire ; cleavable varieties^
10. Diamonds
The following table, compiled by Dr. tJre for the early editions of his dictionary,
will still be found very useful as representing, relatively, the hardness of the mineral
named, although the numbers which express the degree of hardness do not agree with
the scale of MohsL
SubetancM.
Hardneti.
Sp. Orar.
Subatanoet.
Hardneas.
Sp. GraT.
Diamond from Ormus
20
3-7
Sardonyx - • -
12
2-6
Pink diamond -
19
3-4
Occidental amethyst -
11
2-7
Bluish diamond
19
3-3
Crystal -
11
2-6
Yellowish diamond -
19
3-3
Cornelian
11
2-7
Cubic diamond -
18
3-2
Green iasper -
Reddish yellow do -
11
2-7
Ruby
17
4-2
9
2-6
Pale ruby from Brazil
16
8-5
Schorl - . .
10
3-6
Deep blue sapphire -
16
3-8
Tourmaline
10
30
Ditto, paler
17
3-8
Quarts ...
10
2-7
Topaa - - -
15
42
Opal ...
10
2-6
Whitish topas -
14
3-5
Chrysolite
10
8-7
Ruby spinel
13
3-4
Zeolite ...
8
2-1
Bohemian topaz
11
2-8
Fluor ...
7
3-5
Emerald - - -
12
2-8
Calcareous spar
6
2-7
Garnet - • -
12
4-4
Gypsum • - -
5
2-3
Agate - - -
12
2*6
Chalk .
8
2-7
Onyx . . -
12
2-6
HARDWARE, tinder this term is comprehended the articles manofactured of
any of the baser metals. See these respectively.
HARE WOOD. See Stcamobe.
HARTSHORN, SPIRIT OF, is the old name fbr the solution of ammonia in
water, the liquor ammonia of the London PharmacopflBia.
HASSOCK. A term given to a kind of sandstone produced in the quarries of
Kentish Ragstone in Kent. When of good quality it is employed in building the inte-
rior walls of chorchcs. The following is an analysis of Hassock by Dr. Piomby, of
Jdaidstone:—
. Carbonate of lime ....•••63
Alumina .•••...••.4
Oxide ctf iron **••-•. -8
SiUca 32
Small quantities of phosphate of lime, soda, magnesia,
chlorine and sulphuric acid ..... ^
100
HAT MANUFACTURE. (,Vart de Chapeiier, Fr.; Huimacherkunst, Germ.)
Hat is the name of a covering for the head worn by both sexes, but principally by men.
As the art of making hats does not involve the description of any curious machinery,
or any interesting processes, we shall not enter into very minute details upon the
subject. It will be sufficient to convey to the reader a general idea of the methods
employed in this manufacture.
The materials used in making stuff hats are the furs of hares and rabbits freed fW>m
the long hair, together with wool and beaver. The beaver is reserved for the finer
444
HAT MANUFACTURE.
hate. The fur b first l^ud upon a bardie made of wood or wire, with longitudinal
openings; and the operator, by means of an instroment called the bow, (which is s
piece (^ elastic ash, six or seven feet long, with a catgat stretched between its two
extremities, and made to vibrate by a bowstick,) causes the vibrating striog to strike
and play upon the fur, so as to scatter the fibres in aU directions, while the dost and
filth descend through the grids of the hurdle.
After the fur is thus driven by the bow {h>m one end of the hurdle to the other, it
forms a mass called ^ bat, which is only half the quantity sufficient for a hat The
bat or canade thus formed is rendered compact by pressing it down with the hardenmg
9kin (a piece of half- tanned leather), and the union of the fibres is increased by cover-
ing them with a cloth, while the workman presses them together repeatedly with his
hands. The cloth being taken off, a piece of paper, with its comers doubled in, so as
to give it a triangular outline, is laid above the bat The opposite edg^ of the bat
are then folded over the paper, and being brought together and pressed again with the
•hands, they form a conical cap. This cap is next laid upon another bat, ready har-
dened, so that the joined edges of the first bat rest upon the new one. This new bat
is folded over the other, and its edges joined by pressure as before; so that the join*
ing of the first conical cap is opposite to that of the second. This compound iMit is
now wrought with the hands for a considerable time upon the hurdle between folds of
linen cloth, being occasionally sprinkled with clear water, till the hat is bastmed^ or
rendered tolerably firm.
The cap is now taken to a wooden receiver, like a very flat mill-hopper, consistmg
of eight wooden plains, sloping gently to the centre, which contains a kettle filled with
937 water acidulated with sulphuric acid. The
technical name of this vessel is the baUety^ It
consists of a kettle a, fig, 932 ; and of the
planks, B, c, which are sloping planes, usually
eight in number, one being allotted to each
workman. The half of each plank next the
kettle is made of lead, the upper half of ma-
hogany. In this liquor the hat is occasionally
dipped, and wrought by the hands, or some-
times with a roller, upon the sloping planks.
It is thus fulled or thickened during four or
five hours ; the knots or hard substances are
picked out by the workman, and fresh felt is
added by means of a wet brush to .those parts
that require it. The beaver, is applied at the
end of this operation. In the manufacture of
beaver hats, the grounds of beer are added to
the liquor in the kettle.
Stopping^ or thickening the thin spots, seen by looking through the body, is per-
formed by daubing on additional stuff with successive applications of the hot acidulous
liquor from a brush dipped into the kettle, until the body be sufficiently shrunk and
made uniform. After drying, it is stiffened with varnish composition rubbed in with
a brush; the inside surface being more copiously imbued with it than the outer; while
the brim is peculiarly charged with the stiffening.
When once more dried, the body is ready to be coveredy which is done at the baOery,
The first cover of beaver or napping, which has been previously bowed, is strew^
equably over the. body, and patted on with a brush moistened with the hot liquor,
until it gets incorporated ; the cut ends towards the root, being the points which spon-
taneously intrude. The body is now pat into a coarse hair cloth, then dipped and
rolled in the hot liquoc, until the xoot ends of the beaver are thoroughly worked in.
This is technically called rolling off, or roughing^ A strip for the brim, round the
edge of the inside, is treated in the same way; whereby everything is ready for the
second cover (of beaver), which is incorporated in like manner ; the rolling, &c. being
continued, till a uniform, close, and well-felted hood is formed.
The hat is now ready to receive its proper shape. For this purpose the workman
turns up the edge or brim to the depth of about 1^ inch, and then returns the point of
the cone back again through the axis of the cap, so as to produce another inner fold
of the same depth. A third fold is produced by returning the point of the cone, and
so on till the point resembles a fiat circular piece having a number of concentric folds.
In this state it is laid upon the plank, and wetted with the liquor. The workman pulls
out the point with his fingers, and presses it down with his hand, turning it at the
same time round on its centre upon the plank, till a flat portion, equal to the crown
of the hat, is rubhed out This flat crown is now placed upon a block, and, by press-
ing a string called a.ccwima/K/cr, down the sides of the block, he forces the parts a^ja-
HAT MAJSrUFACTURE.
445
cent to the croVn, to assume a cylindrical figure. The brim now appears like a
puckered appendage round the cylindrical cone ; but the proper figure is next given
to it, by working and rubbing it. The body is rendered waterproof and stiff by being
imbued with a Tarnish composed of shellac, sandarach, mastic, and other resins dis-
solved in alcohol or naphtha.
The hat being dried, its nap is raised or loosened with a wire brush or card, and
sometimes it is preyiously pounced or rubbed with pumice, to take off the coarser
parts and afterwards rubbed over with seal skin. The hat is now tied with pack«
thread upon its block, and is afterwards dyed.
The dyed hats are now removed to the stiffening shop. Beer grounds are next
applied on the inside of the crown, for the purpose of preventing the glue from coming
through ; and when the beer grounds are dried, glue (gum Senegal is sometimes used),
a little thinner than that used by carpenters, is laid with a brush on the inside of the
crown, and the lower surface of the brim.
The hat is then softened by exposure to steam, on the steaming basin, and is
brushed and ironed till it receives the proper gloss. It is lastly cut round at the brim
by a knife fixed at the end of a gauge, which rests against the crown. The brim,
however, is not cut entirely through, but is torn off so as ta leave an edging of beaver
round the external rim of the hat The crown being tied up in a gauze paper, which
is neatly ironed down, is then ready for the last operations of lining and binding.
The furs and wools of which hats are manufiictured contain in their early stage of
preparation, kempt and HairM, which must be removed in order to produce a material
for the better description of hats. This separation is effected by a sort of winnowing
machine, which wafts away the finer and lighter parts of the furs and wools from the
coarser.
The annexed figures represent Mr. 011erenshaw*s machine, generally employed for
ironing hats. Fig. 938 is the frame-work or standard upon which three of these
lathes are mounted, as A^ b, c. The lathe A is intended to be employed when the
crown of the hat is to be ironed. The lathe b, when the flat top, and the upper side
of the brim is ironed, and lathe c, when its under side is ironed ; motion being given to
the whole by means of a band passing from any first mover (as a steam-engine, water-
wheel, &c.) to the drum on the main shaft a a. From this drum a strap passes over
the rigger b, wluch actuates the axle of the lathe a. On to this lathe a sort of chuck
is screwed, and to the chuck the block c is made fast by screws, bolts, or pins. This
block is represented in section, in order to show the manner in which it is made, of
seyeral pieces held fast by the centre wedge-piece, as seen at^. 939.
The hat-block being made to turn round with the chuck, at the rate of about twenty
turns per minute, but m the opposite direction to the revolution of an ordinary turning
lathe, the workman applies his hot iron to the surface of the hat, and thereby smooths
it, giving a beautiful glossy appearance to the beaver ; he then applies a plush cushion,
and rubs round the surface of the hat while it is still revolving. The hat, with its
block, is now removed to the lathe b, where it is placed upon the chuck d, and made to
turn in a horizontal direction, at the rate of about twenty revolutions per minute, for
the purpose of ironing the flat-top of the crown. This lathe b moves upon an upright
shaft e, and is actuated by a twisted band passing from the main shaft round the
rigger/. In order to iron the upper surface of the brim, the block c is removed from
446
HAT MANUFACTUBE.
the laihe, and taken oat of the liat, when the block fig, 940 u monntel upon the chuck
d, and made to torn nnder the hand of the workman, as before.
The hat is now to be removed to the lathe c, where it is introdveed in an inTerted
position, between Uie arms ^ g supporting the rim A A, the top sarfiKse of which is
shown at^. 941. The spindle i of the lathe tarns by similar means to the last, bnt
slower ; only ten tarns per minate will be solBcient The workman now smooths the
nnder side of the brim, by drawing the iron across it, that is from the centre outwards.
The hat is then carefhily examined, and all the bars and coarse hairs picked oat, after
which the smoothing process is performed as before, and the dressing of the hat is
complete. This description of the manatactnre of the bearer hat has been retained,
though it is now bat little practised, the silk hat having taken its place.
Silk hats, for seyeral years after they were manufactured, were liable to two objec-
tions ; first, the body or shell oyer which the silk covering is laid, was, from its hard-
ness, apt to hurt the head ; second, the edge of the crown being much exposed to blows,
the silk nap soon got abraded, so as to lay bare the cotton foundation, which b not
capable of taking so fine a black die as the silk; whence the hat assumed a shabby
appearance. Messrs. Mayhew and White, of London, proposed to remedy these
defects, by making the hat body of stuff or wool, and relieving the stifiheas of the
inner part round the brim, by attaching a coating of beaver upon the under side of
the brim, so as to render the hat pliable. Round Uie edge of the tip or crown, a quan-
tity of vhat is called stop wool is to be attached by the ordinary operation of
bowing, which will render the edge soft and elastic. The hat is to be afterwards
dyed of a good black colour, bom outside and inside ; and being then properly
stiffened and blocked, is ready fbr the coyering of silk.
The plush employed for covering silk hats, is a raised nap or pile woven usually npou
a cotton foundation ; and the cotton, being inciqMible of receiving the same brilliant
black dye as the silk, renders the hat apt to turn brown whenever the silk nap is
partially worn off. To counteract this evil, the foundation of the plush is now
frequently made entirely of silk. To these two improvements, now pretty generally
introduced, the present excellence of the silk hats may be ascribed.
Fig, 942 is a side view of the carding engine, employed in preparing the silk for
hats, with a horizontal plan or view of the lower part of the carding machine^ showing
the operative parts of the winding apparatus, as connected to the carding engine. The
doffer cylinder is covered with fillets of wire cards, such as are usoally employed in
carding engines, and these fillets are divided into two, three, or more spaces extending
round the periphery of the cylinder, the object of which division is to separate the
sliver into two, three, or more breadths, which are to be conducted to and wound apon
distinct blocks, for making so many separate hats or caps.
HAT MANUFACTURE, 447
The principftl cylinder of the carding engme, is made to revolTe by a rigger npon
its •xJie, actuated by a band from any first mover as usual, and the subordinate rollers or
eylinders belonging to the carding engine, are all tamed by pulleys, and bands, and
gear, as in the ordinary construction.
The wool or other material is supplied to the feeding cloth, and carried through
the engine to tiie doffer cylinder, as in other carding engines ; the do£fer comb is
actuated by a revolTing cnmk in the common iray, and by means of it the slivers are
taken from the doffer cylinder, and thence received on to the surfaces of the blocks e e.
These blocks, of ▼hich two only are shown to prevent confusion, are mounted upon
axles, supported by soitable bearings, in a carriage//, and are made to revolve by means
of a band g g, leading from a pulley on the axle of a conical drum beneath. The band
g poases over a puUey A, affixed to the axle of one of the blocks, while another pulley
t, upon the same axle, gives motion, by means of a band, to as many other blocks as
are adapted to the machine.
As it is necessary in winding the slivers on to the blocks, to cross them in different
directions, aud also to pass the sliver over the hemispherical ends of the blocks, in
order that the wool or other material may be uniformly spread over the surface in
forming the cap or hood fbr the shell or foundation of the intended hat, the carriage
/^ with the blocks, is made to traverse to and fro in lateral directions upon rollers at
each end.
This alternating motion of the carriage is caused by a horizontal lever / / (seen in
the horisontal yiew Jig. 942), moving upon a fulcrum pin at m, which lever is attached
to the carriage at one extremity a, and at the other end has a weighted cord which
draws the side of this lever against a cam wheel o. This cam is made to revolve by
means of a band and pulley, which turns the shaft and endless screw 9, and this
endlen screw, taking into a toothed wheel r, on the axle of the cam o, causes the cam
to revolve, the periphery of which cam running against a friction roller on the side of
the lever ^ causes the lever to vibrate, and the carriage//, attached to it, to traverse to
and fro upon the supporting rollers, as described. By these means the slivers are
laid in oblique directions (varying as the carriage traverses) over the surface of the
blocks.
The blocks being conically fonned, or of other irregular figures, it is necessary, in
order to wind the slivers with uniform tension, to vary their speed according to the
diameter of that part of the block which is receiving the sliver. This is effected by
giving different velocities to the pulley on the axle of the conical drum #, corresponding
with e. There is a similar conical drum t, placed in a reverse position in the lower
part of the frame, which is actuated by a band from any convenient part of the machioe
passing over a pulley «, upon the axle of t. From the drum f, to the drum «, there is
a band o, which is made to slide along the drums by the guidance of two rollers at the
end of the lever L
It will now be seen that when the larger diameter of the cam wheel o forces the
lever outwards, the band v will be guided on to the smaller part of the conical drum t,
and the larger part of s, consequently the drum 9 will at this time receive its slowest
motion, and the band g will turn the blocks slower also ; the reverse end of the lever I,
having by the same movement slidden the carriage into that position which causes the
slivers to wind upon the larger diameter of the blocks.
When the smaller diameter of the cam is acting against the side of the lever, the
weighted cord draws the end of the lever to the opposite side, and the band t; will be
guided on to the larger part of the cone f, and the smaller part of the cone a ; con-
sequently, the quicker movement of the band g will now cause the blocks e e to revolve
with a corresponding speed. The carriage/ will also be moved upon its rollers to
the reverse side, and the sliver of wool or other material be now wound upon the
smaller parts and ends of the blocks, at which time the quicker rotation of the blocks is
required. It may be here observed, that the cam wheel 0 should be differently formed
according to the different shaped blocks employed, so as to produce the requisite move*
meats of the lever and carriage suited thereto.
It only remains to state that there are two heavy conical rollers 10 tr, bearing upon
the peripheries of the blocks e e, which turn loosely upon their axles by the friction
of contact, for the purpose of pressing the slivers of wool or other material on the
blocks as it comes from the doffer cylinder of the carding ^gine, and when the blocks
have been coated with a sufficient quantity of the sliver, &e smaller end of the pressing
rollers is to be raised, while the cap is withdrawn from the block. The process being
continued as before, the formations of other bodies or caps is effected in the manner
above described.
After the caps or bodies of hats, &c. are formed in the above described machine, they
are folded in wet cloths, and placed upon heated plates, where they are rolled under
inressure, for the purpose of being hardened. Fig, 988 represents the front of threo
448
HAT MANUFACTUEE.
timatxtaaa, tlietoptof wliich »re covered with iron plata bbb. UponthMe plates,
which tie hHted by the furnace below, or bj iteun, the bodict wnpped id the wet
elothi cce, are placed, and preiied upon by the Bapi or earerg d d i, sliding upoa
guide roda. id which flapa a travening motion ii given, bj memu of chaina attached to
an altemaliog bar c t. Thii bar ii moved by a rotary crank./, which hai its motion
bj palleyi ftx>m any actuating power. When any one of the ftapi ii turned up to
remove the bodies tmia beneath, the chaini hang loosely, and the Bap remaiiu
Theie cap* or hat bodies, after having been hardened ie the manner aboTe described,
may be felted in tbe usiul way by band, or they are felled in a ftalling mill by the
uloal process employed for milling cloths, except that the hat bodies are oecanonally
taken out of the fttlllng niill, and passed between rollers, for the purpose of rendering
the ftlt more perfecL
Mr. Carej, of Baaford, obtained a patent in October, 1834, for an mventian of certain
machiDery to be employed in the msnaJactnre of hats, which is ingenious and seem*
to be worthy of notice in this place. It consists in the adaptation of a system of rollera,
forming a machiae, by means of which the-operatioo of roughing or plaiting of hata,
an may be perfonned ; that is, tbe
beaver or other for may be
made to attach itself, and wnrii
into the felt or hat body, with-
out the necessity of the ordi-
nary """""' operations.
The accompanying draw-
ings represent the machine in
Kversl views, for the purpnae
ofsh
a parts. Fig. 944 is a
fhmt elevation of the machine ;
fy. 945 i« a side elevation of
tbe same; J^. 9-IB is a loa^-
tudinal lection of tbe machine i
and Jig. 947 is a transvcne
section ; the similar letters in-
dicating the same parti in ail
the fignres.
Upon a brick or other tnit-
able base, a fnmaee or fire-
place a, is made, having a de-
•cending flue b, for the pm^
pose of earryiog away the
smoke. A pan or shallow
vessel e c, formed of lead, i*
placedoverthefumacej which
vessel is intended to contaio a
sour liquor, as a solution of
vitriolic acid and water. On
tbe edge of this pan is erected
g4S a wooden casing ddd, which
encloses three sides, leaving
the fourth open for the pur-
pose of obtaining access to tbe
working apparatus within. A.
series of what may be termed
lantern rollers, e e e, is mounted
on axles toming in the side
cauDgs ; and another series of
similar lantern rollers,///, is
in like manner mounted above.
These lantern rollers are made
to revolve by meant of bevel
pinions, fixed on the ends of
their axles, which sre tamed
by similar bevel wheels on the
lateral ihafti g, and h, driven by a winch, i", and gear, as shown in^. 944 and 94S.
Having prepared the bodies of the bats, and laid upon their surface* tbe usual coal-
ings of beaver, or other fur, when so prepared they are to be placed between hak
HAT MANUFACTURE. 449
cloths, and these hair cloths folded within a canTas or other suitable wrapper. Three
or more hats being thus enclosed in each wrapper, the packages are severally pnt into
bags or pockets in an endless band of sackcloth, or other suitable material; which
endless band is extended over the lantern rollers in the machine.
In the first instance, for the purpose of merely attaching the furs to the felts (which is
called slicking, when performed by hand), Mr. Carey prefers to pass the endless band
k kky with the covered hat bodies, over the upper series///, of the lantern rollers, in
order to avoid the inconvenience of disturbing the fur, which might occur from sub-
ject ing them to immersion in the solution contained in the pan, before the fur had
become attached to the bodies.
After this operation of slicking has been effected, he distends the endless handkkk,
over the lower series of lantern rollers eee, and round a carrier roller /, as shown in
fig. 946; and having withdrawn the hat bodies for the purpose of examining them,
and changing ^eir folds, he packs them again in a similar way in flannel, or other
suitable cloths, and introduces them into the pockets or bags of the endless bands, as
before.
On putting the machinery in rotatory motion in the way described, the hats will be
carried along through the apparatus, and subjected to the scalding solution in the pan,
as aUo to the pressure, and .to a tortuous action between the ribs of the lantern rollers,
as they revolve, which will cause the ends of the fur to work into the felted bodies of
the hats, and by that means permanently to attach the nap to the body ; an operation
which when performed by hand, is called rolling off.
A varnish made by dissolving shellac, mastic, sandarac, and other resins in alcohol,
or the naphtha of wood vinegar, is generally employed as the stiffening and water-
proof ingredient of hat bodies. A solution of caoutchouc is often apphed to whale-
bone and horse- hair hat bodies.
The following recipe has been prescribed as a good composition for stiffening hats :
four parts of shellac, one part of mastic, one half of a part of turpentine, dissolved in
^ve parts of alcohol, by agitation and subsequent repose, without the aid of heat This
stiffening varnish should be applied quickly to the body or foundation with a soft ob-
long brush, in a dry and rather warm workshop; the hat being previously fitted with
its inside turned outwards upon a block. The body must be immediately afterwards
taken off, to prevent adhesion.
Another method of proceeding is, first to dissolve the gums by agitation in twice
the due quantity of spirits, whether of wood or wine, and then, after complete solu-
tion, draw off one half the spirit in a still, so as to bring the stiffening to a proper
consistency. No sediment subsequently appears on diluting this solution, however
much it may be done.
Both the spirit and alkali stiffenings for hats made by the following two recipes, have
been tried by some of the first houses in the trade, and have been much approved of: —
Spirit Stiffening.
7 pounds of orange shellac.
2 pounds of gum sandarao^
4 ounces of gum mastic
Half a pound of amber resin.
1 pint of solution of copal.
I gallon of spirit of wine or wood naphtha.
The shellac, sandarac, mastic, resin, are dissolved in the spirit, and the solution of
copal it added last
Alkali Stiffening. ,
7 pounds of common block shellaa
1 pound of amber resin.
4 ounces of gum thus.
4 ounces of gum mastic
6 ounces of borax.
Half a pint of solution of copal.
The borax is first dissolved in a little warm water (say I gallon) ; this alkaline
liquor is now put into a copper pan (heated by steam), together with the shellac, resin,
thus, and mastic, and allowed to boil for some time, more warm water being added
occasionally until it is of a proper consistence.
Hat-Dyeing, — The ordinary batH for dyeing hats employed by the London manu-
facturers consists, for 12 dozen, of —
144 pounds of logwood ;
12 pounds of green sulphate of iron, or copperas ;
7^ pounds of verdigris.
Vol. ir. G G
450 HAT MANUFACTURE.
Tbe copper ii niutdly made of a lemi-cjlindrical ihape, tad (honkl be larroiiDded
with BD iroD jacket or cas«, into which steam mar be admitted, w> aa to raise the tem-
perature of the inlenorbath to 190° F., but no higher, otbemiie the heat is apt to
a(Tect the Btiffening Timtsb. c&lled Che gnm, with which the body of the hat has heeu
imbued. The logwood hsTing been introduced and digested for soue time, the
copperag and verdiKTis are added in ancceeuTe qnantidei, and in die above proportioiu,
aloQff with every successive two or three doiens of hats, sospeoded upon the dipfaog
machine. Each set of hats, after beiog exposed to the batb with oocasional airingi
daring 40 minutes, is taken off the pega. and laid oat upon tbe ground to be mon com-
pletely blackened by the perozidisement of the iron with the atmospberie oxjgen. la
3 or 4 hours [he dyeing is completed. When fully dyed, the bats are well washed in
running water-
Mr. Baffum states tbat there are four principal object* accompliibed b7 bta pUcDt
invention tor dyeing bats : —
1. In the operation;
2. The production of a better colour ;
3. The prevention of any of the damages to which bate are liable in tbe dyeing ;
4. The accompli sbment of the dyeing process in a much shorter time thui b^ the
usual metbods, and conseijuently leuening tlu! injnrioas effects of the dye-bath npon
the texture of the haL
Fig. 948 shows one method of conitrocting tbe apparatus, a a is a tcmi-eylindrie^
In the face of these rims a number of pegs or blocks are set at nearly equal di
apart, upon each of which pegs or blocks it is intended (o place a hat, and as tbe wheel
rirvolves, to pass it into and out of the dyeing liquor in the vat or copper. This wheel
ms}' be kept revolving with a very slow motion, either by gear coooectlng its axle,c,
vilh any moving power, or it may be turned round by hand, at intervals of ten
minutes ; whereby tbe hats hung upon the pegs will be altemalely immersed for tbe
Epace of ten minutes in the dyeing liquor, Bnd then for the same space exposed to the
atmospheric air. In this way, the process of dyeing, it is supposed, may be greally
facilitated and improved, as tbe occasiousl transition from the dye vat into the sir,
and from the air again into the bath, irill enable the oxygen of the atmosphere to
Btrike the dye more perfectly and eipeditionsly into the msterials of which the hst
is composed, than by a continued immersion in the bath for a much longer lime.
A variation in the mode of performiog this process is loggested, aod the apparsini
^g. 949 is proposed to be employed, a a is a square vat or vessel containing tbe dye-
ing liqoor -, 6 & is a frame or rack having a nomber of pegs placed in it for hanging
the Imla npon, which are about to he dyed, in a manner similar to the wheel above
described. This frame or rai;k is suspended by cords from a crane, and may in tbat
way be lowered down with the hala into the val, or drawn up and exposed in the air;
changes which may be made every 10 or 30 minutes.
Mr. William Hodge's patent improvements in hat dyeing, partly founded npoit an
invention of Mr. Bowler, consist, first in causing every alternate frame to which tbe
fiiiai>eaders or bloclia are to be attached, to slide in and out of grooves, for the purpow
of more easily removing the said auspenders when required. Fig. 950, represents the
improved dyeing frame, consibling of two circular rims, a a, which are connected to-
gether at lop and bottom, by three filed perpendicular bars or the frame-work i i6-
Two other perpendicular frames, c c, similar to the former, slide in grooves, didd.
HAT MANUFACTURE.
451
95S
950
951
fixed to the upper and lower rims. These grooves haye anti-fraction rollers in them
for the purpose of makmg the frames c c, to slide in and out more freely. The
aospenders or suhstitutes for
blocks, by these means, may be
more easily got at by drawing
out the frames e c, about half
way, when the suspenders, which
are attached to the frames with
the hats upon them, may be
easily reached, and either re-
moved or altered in position;
and when it is done on one side,
the sliding-frame may be broaght
out on the other, and the re-
maining quantity of ** suspenders**
undergo the same operation.
The patentee remarks, that it
is well known to all hat dyers,
that after the hats have been in
the dyeing liquor some time, they
ought to be taken out and ex-
posed to the action of the atmo-
spheric air, when they are again
immersed in the copper, that
part of the hat which was upper-
most in the first immersion, being
placed downwards in the second.
This is done for the purpose of obtaining an uniform and regular dye. The patentee's
mode of carrying this operation into effect, is shown in the figure : € e are pivots
for the dyeing-frame to turn upon, which is supported by the arms f, frt>m a crane
above. The whole apparatus may be raised up or lowered into the copper by
means of the crane or iAiev mechanism. When the dyeing>frame is raised out ot
the copper, the whole of the suspenders or blocks are reversed, by turning the appa-
ratus over upon the pivots e e, and thus the whole surfaces of the hats are equally
acted upon by the dyeing material.
It should ie observed, that when the dyeing-frame Is raised up out of the copper,
it should be tilted on one side, so as to make idl the liquor run out of the hats, as also
to cause the rims of the hats to hang down, and not stick to the body of the hat, or
leave a bad place or uneven dve upon it The second improvement described by the
patentee, is tiie construction of ** suspenders," to be substituted instead of the ordinary
blocks.
These ** suspenders " are composed of thin plates of copper, bent into the required
form, that is, nearly resembling that of a hat block, and made in such a manner as
to be capable of contraction and expansion to suit different sized hats, and keep them
distended, which may be altered by the workman at pleasure, when it is required to
place the hats upon them, or remove them therefrom. The dyeing-frame at^. 950,
IS shown with only two of these '* suspenders,** in order to prevent confusion. One
of these suspenders is represented detached oX fig. 951, which exhibits a side view;
and^. 952, a front view of the same. It will be seen by reference to the figure, that
the suspenders consist of two distinct parts, which may be enlarged or collapsed by a
variety of means, and which means may be suggested by any competent mechanid.
The two parts of the suspenders are proposed to be connected together by arms gg^
and at the junction of these arms a key is connected for turning them round when
required. It will be seen on reference to the tront view, fig, 958, that the *' sus-
penders" or substitutes for blocks are open at the top or crown part of the hat; this
IS for the purpose of allowing the dyeing liquor to penetrate.
From the mixture of copperas and verdigris employed in the hat dye, a vast quan-
tity of an ochreous muddy precipitate results, amounting to no less than 25 per cent
of the weight of the copperas. This iron mud forms a deposit upon the hats, which
not only corrodes the fine filaments of the beaver, but causes both them and the felt
stuff to turn speedily of a rusty brown. There is no process in the whole circle of
our manufactures so barbarous as that of dyeing stuff hats. No ray of chemical
science seems hitherto to have penetrated die dark recesses of their dye shops. Some
hatters have tried to remove this corrosive brown ochre by a bath of dilute sulphuric
acid, and then counteract the evil effect of the acid upon the black dye by an alkaline
hath ; but with a most unhappy effect Hats so treated are most deceptive and
Ga2
452 HEAT REGULATOR.
unprofitable ; as they tarn of a dirty brown hue when exposed for a few weeks to
sunshine and air.
The annual value of the hats manufactured at present in the United Kingdom is
estimated at 3,000,000/. sterling. The quantity exported in 1857, was 149,946 dcMEens,
Talued at 292 19S/.
HAWTHORN. (JE>tnei?&ifu;A«,Fr.; Weiudom, Qerm,) Cratagus oxycoMtha, JAan.
This shrub has a hard whitish wood, bat as it is small and difficult to work it is not
much used.
H A YESSINE. A borate of lime, which is found abundantly on the western cosot
of America, so called from its discoverer. It has been introduced for use in our glass
manufacture, and is used by our potters. See Borax.
HAZEL. {Hoisetierf Fr.; HaseUtande, GemL) The Corylus aoeUana, a small
anderwood, used a little in turnery and for the manufacture of toys.
HAZEL. A north of England term for a hard grit
HAZEL MOULD. The name given in Hampshire to a light loamy soiL
HEARTH {Foyer, Fr. ; Heerde, Germ.) is the flat or hollow space in a smelting
furnace upon which the ore and fluxes are subjected to the influence of flame. See
Copper, Iron, Metaixurgt, &c.
HEARTHSTONE. A soft stone employed for whitening door steps, &c. An
enormous quantity of hearthstones are brought to London from the quarries at God-
stone.
HEAT. The Force or Principle upon which the conditions, relatively, of solid,
fluid, and aeriform states depend. That which produces the sensation of warmth.
The discussion of the habitudes of heat with the different kinds of matter belongs
to physico-chemical science, and will be treated of in Ure*s Dictionary of Chemistry.
It will suffice in this place, to state succinctly those laws which have, more directly, a
bearing on any of our manufacturing processes.
Heat and motive power are mutually convertible, and heat requires for it» prodwctitm^
and produces by its disappearance, motive power in the proportion of 772 foot'-poumds fur
each Fahrenheit unit of heat. — Eankine.
This unit of heat has been established by Dr. Joule to be the amount of heat re-
quired to raise the temperature of one pound of liquid water by one degree of Fahren-
heit. A falling weight, or any other mode of motion, produces a definite quantity
of heat according to this htw.
If the total actual heat of a homogeneous and uniformly hot substance be conceived to
be divided into any numbers of equal parts, the effect of those parts in causing work to be
performed will be equal. — JRankine.
Or in other words, of a given equivalent of heat, fW>m whatever soarce prodacedy
the work which it can effect is always an equal and constant quantity.
Heat may be produced by friction, as we see in the development of it, powerfully,
in the axles of railway carriages insufficiently lubricated. By the attrition of two
pieces of wood ignition can be obtained.
Heat is developed in the mixture of bodies of different densities, snch as spirits of
wine and water, or sulphuric acid and water, there being a diminntion of volome in
each case.
Heat is produced by many conditions of chemical combination, in namerona cases
so energetically as to produce intense combustion and even explosion.
Heat is obtained b^ combustion for our ordinary manufacturing processes, and
domestic uses. This is a chemical union of one body with another, as carbon with
■oxygen ; but to effect this, an excitant appears necessary or a continually increasing
excitement of the energy upon which heat depends, as, the application of flame in
one case and the phenomena of spontaneous combustion in another.
Electricity by its disturbing power, developes heat, and this all important force is
also rendered manifest by the processes of vitality (vital or nervous force).
Dr. Joule has clearly shown, that whatever may be the source of heat, a cer-
tain fixed elevation of temperature is produced by a given amount of mechanical,
chemical, electrical, or vital disturbance, and that the mechanical value of the cause
producing the heat is exactly represented by the mechanical effect obtained.
For a full discussion of this important point, see the Memoirs of Joule, of Thomson,
and of Rankine, in the Philosophical Transactions of London and Edinburgh. The
applications of heat will be found under the proper heads. See also Spheroidal
State.
HEAT' REGULATOR, or Thermostat. The name given by M. Bonnemain to
an ingenious apparatus for regulating the temperature of his incubating stove rooms.
See Incubation, Artificial, for the manner of applying the Heat-Regulator.
The construction of the regulator is founded upon the unequal dilatation of different
metals by the same degree of heat. A rod of iron x,Jig. 953, is tapped at its lower
3
HEAT REGULATOR.
4o3
end into a brass nut y, enclosed in a leaded box or tube, terminated above by a brass
collet z. This tube is plunged into the water of the boiler, alongside of the smoke-
pipe. Fig. 954, is a bird's-eye view of the dial, &c. The expansion of the lead
being more than the iron for a like degree of temperature, and the rod enclosed within
the tube being less easily warmed, whenever the heat rises to the desired pitch, the
elongation of the tube puts the collet t in contact with the heel, a, of the bent lever
a, 6, (/; thence the slightest increase 953 /P^^^'-
of heat lengthens the tube anew, -j, ^_^r^^ ^-^ ^
and the collet lifting the heel of ► p —
the lever, depresses the other end ,\,,^ '"^-^
d through a much greater space,
on account of the relative lengths
of its legs. This movement ope-
rates near the axis of a balance-bar
e, sinks one end of this, and there-
by increases the extent of the move-
ment, which is transmitted directly
to the iron skewer v. This push-
ing down a swing regiAer dimi-
nishes or cuts off the access of air
to the fire-place. The combustion
is thereby obstructed, and the tem-
perature falling by degrees, the tube shrinks and disengages the heel of the lever. The
counterpoise y, fixed to the balance beam «, raises the other extremity of this beam by
raising the end d of the lever as much as is necessary to make the heel bear upon the
collet of the tube. The swing register acted upon by this means, presents a greater
section to the passage of the air ; whence the combustion is increased. To counter-
balance the effect of atmospheric changes, the iron stem which supports the regulator
is terminated by a dial disc, round the shaft of the needle above h^fig, 954 ; on turn-
ing this needle, the stem below it turns, as well as a screw at its under end, which raises
or lowers the leaden tube. In the first case the heel falls, and opens the swing re-
gister, whence a higher temperature is required to shut it, by the expansion of the tube.
We may thus obtain a regularly higher temperature. If, on the contrary, we raise
the tube by turning the needle in the other direction, the register presents a smaller
opening, and shuts at a lower temperature ; in this case we obtain a regularly lower
temperature. It is therefore easy, says M. Bonnemain, to determine d priori the degree
of temperature to be given to the water circulating in the stove pipes. In order to
facilitate the regulation of the apparatus, he gradiutted the disc dial, and inscribed
upon its top and bottom, the words Strong and Weak heat.
Thermostat, is the name of an apparatus for regulating temperature, in va-
porisation, distillations, heatins baths or hothouses, and ventilating apartments, &c.;
for which I obtained a patent m the year 1831. It operates upon the physical prin-
ciple, that when two thin metallic bars of different expansibilities are riveted or
soldered facewise together, any change of temperature in them will cause a sensible
movement of flexure in the compound bar, to one side or other ; which movement
may be made to operate, by the intervention of levers, &c., in any desired degree,
upon valves, stopcocks, stove-registers, air-ventilators, &c. ; so as to regulate the
temperature of the media in which the said compound bars are placed. Two long
rulers, one of steel, and one of hard hammered brass, riveted together, answer very
well ; the object being not simply to indicate, but to control or modify temperature.
The following diagrams will illustrate a few out of the numerous applications of this
instrument :
Fig, 955, a, 6, is a single thermostatic bar, consisting of two or more bars or rulers
of differendy expansible solids (of which, in certain cases, wood may be one) : these
bars or rulers are firmly riveted or soldered together, face to face. One end of the
compound bar is fixed by bolts at a, to the interior of the containing cistern, boiler,
or apartment, aim b, whereof the temperature has to be regulated, and the other end
of the compound bar at b, is left free to move down towards c, by the flexure which
will take place when its temperature is raised.
The end b, is connected by a link, b </, with a lever d e, which is moved by the
flexure into the dotted position b g, causing the turning-valve, air-ventilator, or re-
gister, 0 n, to revolve with a corresponding angular motion, whereby the lever will
raise the equipoised slide-damper k t, which is suspended by a link from the end e,
of the lever e d, into the position k h. Thus a hothouse or a water-bath may have
its temperature regulated by the contemporaneous admission of warm, and discharge
of cold air, or water.
GO 3
454
HEAT REGULATOR.
Fig. 956, a 5 c is a thermostatic hoop, immersed horizontally beneath the sarfiieeof
the water- bath of a still. The hoop is fixed at a, and the two ends b c, are ooiinected
by two links b d,cd, with a straight sliding rod dh,to which the hoop will give an
endwise motion, when its temperatiune b
altered ; e, is an adjusting screw-nat on the
rod d h, for setting the leyer / ^, which is
fixed on the axis of the taming-TalTe or cock
/, at any desired position, so that the -valve
may be opened or shat at any desired f em-
peratore, corresponding to the widening of
the points 6, c, and the consentaneons re-
traction of the point d, towards the circnm-
ference a b c of the hoop. ^ A, is an are
graduated by a thermometer, after the screw-
piece e has been adjusted. Through a hole
at A, the guide-rod passes; t, is the cold-
water cistern ; i f k, the pipe to admit cold
water; /, the o'verfiow pipe, at which the
excess of hot water runs off.
Fig, 957 shows a pair of thermostatic bars,
bolted fyst together at the ends a. The
free ends b, c, are of unequal length, so as
to act by Uie cross links d^f,OD. the stop-
cock e. The links are jointed to the handle
of the turning plug of the cock, on opposite
sides of its centre ; whereby that plug will
be turned round in proportion to the widening
of the points 5, c. kg is the pipe communicating with the stopcock.
Suppose that for certain purposes in pharmacy, dyeing, or any other chemical art,
a water-bath is required to be maintained steadily at a temperature of ISO^F. : let the
combined thermostatic bars, hinged together at ej/,fig, 958, be placed in the bath
between the outer and inner vessels
€tyb,e,d, being bolted ftst to the inner
Tessel at g ; and haye their sliding rod i,
connected by a link with a lever fixed
upon the turning plug of the stopcock t,
which introduces cold water from a
cistem m, through a pipe m, i, n, into the
bottom part of the biUh. The length
of (he link must be so adjusted that the
flexure of the bars, when they are at a
temperature of 150°, will open the said
stopcock, and admit cold water to pass
into the bottom of the bath through the
pipe I ff, whereby hot water will be dis-
placed at the top of the bath through
an open overflow-pipe at 9. An oil
^ — bath may be regulated on the same
plan ; the hot oil overflowing from q,
into a refri^ratory worm, from which it may be restored to the cistem m. When a
water bath is heated by the distribution of a tortuous steam pipe through it, as 1 11 o p,
it will be necessary to connect the link of the thermostatic bars with the lever of the
turning plug of the steam-cock, or of the throttle valve t, in order that the bars, by
their flexure, may shut or open the steam passage more or less, according as the tem-
perature of the water in the bath shall tend more or less to deviate from the pitch to
which the apparatus has been adjusted. The water of the condensed steam will pass
off from the sloping winding- pipe inopf through the sloping orifice p. A saline acid
or alkaline bath has a boiling temperature proportional to its degree of concentration,
and may therefore have its heat regulated by immersing a thermostat in it and con-
necting the working part of the instrument with a stopcock t, which will admit water
to dilute the bath whenever by evaporation it has become concentrated, and has acquired
a higher boiling point ^ The space for the bath, between the outer and inner pans, should
communicate by one pipe with the water cistem m, and by another pipe with a safety
cistem r, into which the bath may be allowed to overflow during any sudden excess of
ebullition.
Fig. 961 is a thermostatic apparatus, composed of three pairs of bars d dd, which
are represented in a state of flexure by neat; but they become nearly straight
HEAVY SPAE.
and par»]lel when cold, a 6 e ii ■ guide rod, fixed at od
e, inlhedroDgfHiDeye, hsTiog deep guide
groores >t the lidei. / o, ii tbe work-
iog-rod, which inOTei nndwaja wbeo the
ban d d d, operate by beat or cold. A
square register- plate A g, niaji be affixed
to the Toi/g, so ai to be moved bsckwardt
and forward! thereby, aecordiog to the
Tariationa of lemperalure i or the rod / j,
maj caoae the circular taraing air-regider,
i, to rpTolye hy rack and wheel work, or by
a chain and pidley. The rtgUler -plate h g,
or turning re giiter i. ii liiualed at the ceil-
ing or npper part of tbe cbamber, aod senea
CO let oat bot-aii- A, la a pulley, orer which
a cord mns to nuse or lover a hot-air
regiiter f, which may be situated Dear tbe
floor of the apartnieDtorhDt-houae,lDadmit
.e end by bd a4juatiDg screw
hot ai
lothert
nllled h
•r adjuiting the thermostat, by means of
the screw at e, in order that it may regulate the temperature to any degree.
Fig. 963 represeuta a chimney, fHiraiihed with a pyrotlal, a b c, acting by the linkg
h, d,t,e, oa a damper / h g. The more expansible metal la in tbe present eiamplo
sappoied lo be on the oatside. The plane of the damper-plate will, in this case, be
turned more directly into the paUBge of the draoght through the chimney by increase
of temperature.
Fig. 960 represents a circular laming register, such aa it naed (br a Hove, or stoTe-
grate, or for ventilating apartmeotst it is fuTDished with a series of spiral Ihermoalalio
bars, each bar being fixed Aut at tbe circumference of the circle b, c, of tbe Sxed plate
of the air-regiiter ; and all the bars act in concert at the centreaof the a%i
turning part of the register ; by their ends being inserted between tbit -
teeth of a small pinion, or by being jointed to the central part of the |X
turning plate by amalJ pins. E
Fig. 9S9 represents another errangetnent of my thermoMaUcapparatu i
applied to a circular (nming register, like the preceding, for Tentilating I
apartments. Two paiia of compound t>ars lu'e applied lo as to act in ^
concert, by means of the links a c, A c, on the opposite ends of a short lever F
which is fixed on the central pari of the turning plate of tbe air-register. Q
Tbe two pain of compound bars a b, arc fastened to the circnmftrence J
of the Qied plate of the turning register, by two sliding rods a d, bt, rj
which are furnished with adjusting screws. Their motion or flexure ia W
transmitted by the links a c and £ c, to the taming plate, about its centre, ^
(or the purpose of shutting or opening tbe ventilating sectorial aper- u
ttirea, more or leas, according to the temperature of the air which sur-
rounds the thermostatic turning register. By adjusting the screws a d, and ( c, tbe
turning register ia made to cloae all its apertures at any desired degree of tempera-
tare ; bat whenever the air ia above that temperature, the flexure of the compound bars
will open the apertures,
UEAVB, a nunn-'i ttrm, expressing the dislocation of a lode. See FAin.T.
HEAVY-SPAR, SULPHATE OF BAKYTE8, or CAWS.* (_Spaih pt,anl,Ti.;
ScAiccrtpath, Germ.), is an abundant mineral, wbicb accompaniea veins of lead, silver,
mercnry, &c., but is ottta found, alao, in large masies. lu colour Is usually while,
or flesh coloured. It varies from translucent to opaque. It belongs to [he trimetrio
BTStem, but it occurs in many crystalline forms, of which the cleavage is a right
nioiDboidal prism. It is met with also of a flbrotis, radiated, and granular stmcture.
Its sp. gr. varies from 4-1 to 4-T H -^ 9-5 to 3-&. It bas a strong lustre, between
the folty and the vitreous, aometimea pearly. It melts at 35° Wedgw. into a white
opaque eiuunel. Its coostitneuts are 65'fi7 baryta, and 34-33 sulphuric acid ; but it is
aome^mes rendered impure by oxide of iron, silica, carbonate of lime and alumina,
and commonly by sulphate of strootian. It is not acted upon by acids i decrepitates
before the blowpipe ; and is difficultly fusible, or only on the edges. In the inner
flame ia reduced to a snlphnret, and the globule when moistened smells slightly
hepatic. It is decomposed by calcination in contact with charcoal at a while heat,
into salphuret of baryta ; from which all the baryta salts may be readily formed. Its
chief employment iu commerce is for adulterating white lead { a purpose wbicb it
* Tliet«m CoipAhu bHnstvtLBd ta the opaque nmilTQVBrlvtr, of uieiithjsp
wUta colour, wbica b fonad In DtrbtMn tBd StaOurditain.
/arbonate -
- 443
16
do
- 1045
18
Salphate* -
- 8000
0
do
- 1000
0
do
- 700
0
do
70
0
do
- 550
0
456 HEMATITE.
readily Beires on account of its density. Its presence here is easily detected by dilate
nitric acid, which dissolves the carbonate of lead, and leaves the heavy spar. It is
also a useful ingredient in some kinds of pottery, and glass.
In 1856 the following quantities were raised {Hunt's Mineral Statistics): —
Tons. Cwts.
Alston Moor - - -
Northumberland, FaUowfield
Derbyshire - - -
Lauderdale and Skipton -
Bantry, Ireland
Kirkcudbright
Isle of Arran - •
HECKLE (^Seran, Fr. ; Hechd, Germ.) is an implement for dissevering the fila-
ments of flax, and laying them in parallel stricks or tresses. See Fulz.
HELIOGRAPHY was the name given by M. Niepce to his process for obtaining,
through the agency of the solar rays upon plates of metal or glass covered with resins,
the impression of external objects. The process has been employed of late years in
preparing lithographic stones, and steel or copper plates, for receiving photographic
impressions, which might be subsequently printed from. The name heliography is a
far more appropriate one than photography ; but the latter has become too permanently
fixed in our language to leave any hope of our returning to the former. See Photo-
ORAPHT.
HELIOTROPE is a variety of jasper, mixed with chlorite, green earth, and diaUage ;
occasionally marked with blood red points ; whence its vulgar name oi blood-stone^
HEMATINE is the name given by its discoverer Cbevrenl to a crystalline sub-
stance, of a pale pink colour, and brilliant lustre when viewed in a lens, which he
extracted from logwood, the Hamcttoxylon Campechianum of botanists. It is, in fact,
the characteristic principle of this dye wood. To procure hematine, digest during
a few hours ground logwood in water heated to a temperature of about 130^ Fahr. ;
filter the liquor, evaporate it to dryness by a steam bath, and put the extract in
alcohol of 0'835 for a day. Then filter anew, and after having inspissated the
alcoholic solution by evaporation, pour into it a little water, evaporate gently again,
an<i then leave it to itself in a cool place. In this way numerous crystals of hematine
will be obtained, which mav be purified by washing with alcohol and drying.
When subjected to dry distillation in a retort, hematine affords all the osual products
of vegetable bodies, along with a little ammonia ; which proves the presence of azote.
Boiling water dissolves it abundantly, and assumes an orange-red colour, which passes
into yellow by cooling, but becomes red again with heat. Sulphurous acid destroys
tbe colour of solution of hematine. Potash and ammonia convert into a dark purple-
red tint the pale solution of hematine ; when these alkalies are added in large quantity,
they make the colour violet blue, then brown-red, and lastly brown-yellow. By this
time the hematine has become decomposed, and cannot be restored to its pristine state
by neutralising the alkalies with acids.
The waters of baryta, strontia, and lime exercise an analogous power of decomposi-
tion ; but they eventually precipitate the changed colouring matter.
A red solution of hematine subjected to a current of sulphuretted hydrogen becomes
yellow ; but it resumes its original hue when tbe sulphuretted hydrogen is removed by
a little potash.
The protoxide of lead, the protoxide of tin, the hydrate of peroxide of iron, the
hydrate of oxides of copper and nickel, oxide of bismuth, combine with hematine, and
colour it blue with more or less of a violet cast
Hematine precipitates glue from its solution in reddish fiocks. This substance has
not hitherto been employed in its pure state ; but as it constitutes the active principle
of logwood, it entere as an ingredient into all the colours made with that dye stuff.
These colours are principally violet and black. Chevruel has proposed hematine
as an excellent test of acidity.
HEMATITE {Fer Oligiste, Fr. I'Rotheisenstein, Germ.) is a native reddish-brown
peroxide of iron. This term was applied to this ore of iron by the ancients, on
account of the red colour of its powder, from &c/ia blood.
This species includes specular iron and the old red iron ore (see Ibok, Specui^ar ;
Micaceous). " The varieties of a snb-metaUic or non-metallic lustre were included
under the names of red hematite^ fibrous red iron, or of soft and earthy red ochre^ and
when consisting of slightly coherent scales, scaly red iron or red iron/roth *' (Daiui).
Dana also includes, most injudiciously as it appears, reddle or red chalk, hJcAjatpery day
iron ore, with some others, among the hematites.
• This is manufactured at Llrerpool, WIf an, and Welshpool.
HEMR 457
The hematite proper occurs in a remarkable manner at Whitebayen and at Ulver-
stone. The foUowing analysis of the Whitehayen ore of Cleator Moor by Mr. A.
JDick, shows its peculiar character : —
Peroxide of iron ------- 95*16
Protoxide of manganese ------ o*24
Lime -------.- 0H)7
Phosphoric acid ---.... trace
Sulphuric acid ---...- trace
Bisulphide of iron ....... trace
Insoluble residue ----... S'%S
101'15
Iron, total amount ------- 66*60
The following analysis of the UlTerstone ore is by the same chemist : —
GMrow Ore,
Peroxide of iron ----,-. 86*50
Protoxide of manganese ---.-• o*2l
Lime --------- 277
Magnesia -------- 1-46
Carbonic acid ------- 2*96
Phosphoric acid ---.-.. trace
Sulphuric acid • - • - - - -0*11
Insoluble residua ------- 6*55
100-56
Iron, total amount ------- 60*55
Another ore, that of Lindale Moor, near UWerstone, was analysed by Mr. J.
Spiller.
Peroxide of iron - - - - - - -94*23
Protoxide of manganese ------ o*23
Alumina -------- o*51
Lime --------- 0'05
Magnesia -------- trace •
Phosphoric acid ------ minute trace
Sulphuric acid - • - - - • -0-09
Bisulphide of iron - • - * - - - 0*03
Water, hygroscopic ------ o*39
n combined -»----- 0'17
Insoluble residue ----.-• 5*18
100*88
Iron, total amount ------- 65*98
In 1857 Wl\itehaven district produced of hematite, 323,812 tons ; and in 1858,
348,638 tons ; and the Lancashire or Ulverstone district, 592,390 tons in 1857, and
438,546 in 1858.
A small quantity of the Ulyerstone ore is smelted with charcoal at some furnaces
in the district, and the following quantities of this ore were used at the furnaces near
Whitebayen : —
Cleator Moor furnaces - - - - - -47,311
Harrington „ ------ 3,000
Leaton „ - 6,200
56,511
All the remainder was sent into the other great iron -making districts for mixing with
the argillaceous carbonates, and other ores of iron. See Iron.
HEMATOSIN. The red colouring matter of blood, which is sold in a dry state
for making Prussian blue.
HEMLOCK SPRUCE. The Abies Canadetuh, the wood of which has been used
for railway sleepers, and is employed for laths.
HEMP. (CAanrre, Fr. ; Han/, Germ.) A plant (Cannabis Mtiud), anatiye of India,
but has been long introduced into Europe, and cultiyated extensiyely in Italy, and
in Russia and Poland ; a small quantity has been cultivated in Suffolk, in Lincoln-
shire, and in Ireland.
Hemp is assorted, into clean hemp, out-shot hemp, half clean hemp, and hemp codiUa,
According to M'Culloch, a bundle of clean hemp from Russia weighs 55 to 65 poods;
of out shot, from 48 to 55 poods ; of half clean, 40 to 45 poods ; the pood being equal
to 36 lbs. avoirdupoise
458
HIDK
Manilla Hemp is the produce of the wild hanana, Muaa textilu. ** It is known,"
says Mr. Crauford in hu history of the Eastern Archipelago, ** to our traders aod
navigators under the name of Manilla rope, and is equally applicable to cables and
to standiug or running rigging."
Sunn and Jutb are two Tarieties of hemp. Hemp is used in the manafactnre oi
huckaback for towels and common tablecloths, and of the low priced cloth worn by
agricultural labourers. The largest consumption of this material is in the manor
facture of sail cloth and cordage.
Our imports of hemp were as follows in 1857 : —
Russia
Prussia
Austrian Italy
Philippine Islands
British East Indies
United States
Hanse Towns
Holland
Spain - . -
Other parts -
Hemp dressed.
Hemp undressed.
Codillaofhemp.
Jote.
Cwti.
29,747
4,043
m m
1,874
1,624
Cwtf.
545,266
10,546
22,005
55,861
45,326
42,254
18,680
Cwts.
5,684
2,771
2,045
2,092
1,681
701
Cwts.
53M38
80,215
*
2,180
37,288
739,938
14,975
618,833 1
HEMP SEED. (Chenevis, Fr. ; Hanfsaat Germ.) The seed of the hemp ; it it
used for crushing, for its oil, or as food for birds.
In 1857 we imported 4,727 quarters of hemp seed, the computed real yalne of which
was 10,636/.
HENBANE. The Hyosciamus niger. Henbane is a plant used in medicine, from
which modem chemistry has extracted a new crystalline Tegetable principle called
hyosciamine, which is yery poisonous, and when applied in solution to the eye, deter-
mines a remarkable dilatation of the pupil ; as belladonna also does.
HENNA. The herb used for dyeing the nails in the ^t. See Axkenka.
HE PAR, which signifies liyer in Latin, was a name given by the older chemists
to some of the compounds of sulphur.
HEPATIC AIR. Sulphuretted hydrogen gas.
HERMETICAL SEAL, is an expression derived from Hermes, who was said to
be the parent of Egyptian chemistry. It is used to designate the perfect closure of a
hollow vessel, by the cementing or melting of the lips of its orifice ; as in the case of a
glass thermometer, or matrass.
HERNANDIA OVIGERA. Hemant seeds, some of which are imported fttun
India for tanning.
HESSONITE, or Essonitt. The name given by Hauy to cinnamon stone.
HICKORY. The Juglana alba ; white walnut, a native of America. It is used for
making handspikes, and other elastic tools.
The bark has been recommended by Dr. Bancroft as a yellow dye.
HIDE. (P«aii, Fr. ; Haut, Germ.) The strong skin of an ox, horse, or other large
animaL The lists of imports below will show to what an extent a trade in the skins of
animals is carried on with this country. We receive hides largely fh>m Russia and
the north of Europe. From America there are also large quantities brought to this
country.
The following table shows the number of salted and dry hides which were exported
from Bahia in ue five years ending September, 1855.
1850—51
1851—52
1852—53
1853^54
1854—55
Number of hides.
Price salted.
Price dry.
per hide.
per hide.
90,040
3jdL
4d.
93,484
Sd.
^tL
108,783
S.d.
4Ul.
128,675
4id.
5id,
134,231
U
6d
HONEY. 459
From the Dominican Republic (Puerto Plata) tbe number of hides exported was
in 1854, 15,514; and in 1855, 10,836 ; they went chieflj to the United States.
From Equator (Guayaquil), during 1855, there were exported principally for the
lima market, 26,246, valued at 10,482/. 16«. 8<i.
From Guatemala, 20,991 hides were exported in 1855.
From Salvador, 24,255, valued at 27,347 dollars, in 1855.
HIPPOCASTANUM. The common horse-chestnut
HIPPOPOTAMUS TEETH. See Ivory.
HOG'S LARD, or Axungii the latter name derived from the use to which it was
put by the ancients, l e. to grease the axle of a wheel. It is obtained from all the
hog tribe (Sus scrofa). Hog's lard is largely used in the mannftuiture of ointments,
pomatum, &c. Its proximate analysis gives, according to Braconnot : —
Stearine and margarine, 38 1 elaine, 62.
The stearine is separated and used in the manufacture of candles, and the elaine
sold under the name of Lard OiL The ultimate analysis of lard giyes —
Carbon, 79*2; hydrogen, 11*1; oxygen, 9*7.
HOLLAND. A linen fabric, which is sold when unbleached as broum hoUand, and
which is used when bleached for finer purposes. See Lxnek.
HOLLANDS. A grain spirit manufactured in Holland.
HOLLY. (Xe Houx^ Fr. ; Stechpalme^ Germ.) The Hex aquifohum of Linnaeus, a
British plant Its leaves yield a yellow colouring matter similar to that obtained
from buckwheat The wood is as white as ivory, very hard and fine g^ned, and
susceptible of a high polish ; it is employed for many purposes.
HOMOLOGOUS. A term used in organic chemistry to denote that substances
differ by the constant increment C^H*. Thus, in the great series of acids commencing
with the formic and extending up to the fittty acids, each homologue contains C'H' more
than the one before, and CH* less than the one following, thus :' —
Formic acid - - C^FPO* I Propionic acid - C^H)*
Acetic acid - - C*R*0' \ Butyric acid - - CHW &c— C. G. W.
HONDURAS MAHOGANY. — See Mahooant.
HONES AND HONE SLATEa These are slaty stones which are used in
straight pieces for sharpening tools after they have been ground on revolving grind-
stones. The more important varieties are the following : —
The Norway Ragstone which is the coarsest variety of the hone slates, is imported
in large quantities from Norway. In Chamwood Forest, near Mount Sorrel, in
Leicestershire, particularly from the Whittle Hill quarry, are obtained the Chamley
Forest Stone, said to be one of the best substitutes for the Turkey oilstone, and it
is much in request by joiners and others. Ayr stone. Snake stone, and Scotch stone, are
used especially for polishing copper plates. The Welsh oilstone is almost in equal
repute with the Charnley Forest stone ; it is obtained from the vicinity of Llyn Idwall,
near Snowdon, and hence it is sometimes called IdwaU stone. From Snowdon is also
obtained the cutler's green stone. The Devonshire oihtones, obtained near Tavistock,
which were introduced by Mr. John Taylor, are of excellent quality, but the supply
of them being irregular they haye fUlen mto disuse.
The German razor hone has been long celebrated. It is obtained from the slate
mountains in the neighbourhood of Batisbon, where it occurs in the form of a yellow
yein running through the blue slate, varying in thickness firom I to 18 inches. When
quarried it is sawn into thin slabs, and diese are generally cemented to slices of slate
which serve as a support Sometimes, however, 3ie yellow and the blue slate are cut
out naturally combing There are several other hone stones, which, however, require
no particular notice.
The Twrkey oilstone is said to surpass in its way every other known substance, and
it possesses in an eminent degree the property of abraung the hardest steel ; it is, at
the same time, of so compact and close a nature as to resist the pressure necessary
for sharpening a graver, or any instrument of that description. There are white and
black varieties of the Turkey oilstone, the black being the hardest, and it is imported
in somewhat larger pieces than tbe white ; they are found in the interior of Asia
Minor and are brou^^t down to £hnyma for sale.
HONEY {Mel, Fr. ; Honig, Germ.) is a sweet viscid liquor, secreted in the nectaries
of flowers, collected by the working bees, and deposited by them in the waxen cells
of their combs. Virgin honey is that which is collected from a hive, the bees of which
have neyer swarmed, the common honey is obtained from the older hives. The former,
which is considered the best, is whitish or pale yellow, of a granular texture, a fragrant
smell, and a sweet slightiy pungent taste ; the latter is darker coloured, thicker, and
460
HOP.
not fto agreeable either ia taste or smell. Honey woold seem to be simply collected
by the bees, for it consists of merely the vegetable products ; such as the sugars uf
grape, gum, and manna ; along with mucilage, extractive matter, a little vax, and acid.
Narbonne honey, the flavour of which is so much admired, owes its peculiarity to
the flowers on which the bees feed.
Trebizond honey has been long celebrated for its intoxicating qualities. The descrip-
tion given in Xenophon's Retreat of the Ten Thousand is well known. Many examples
of poisonous honey are on record.
HONEY COMB. The waxen cells of the bee. See Wax.
HONEY-STONE (3f«ffite, Fr. ; Honigetetn, Germ.) is a mineral of a yellowish
or reddish colour, and a resinous aspect, crystallising in octahedrons with a square
base ; specific gravity 1*58. It is harder than gypsum, but not so hard as calc-spar ; it
is deeply scratched by a steel point ; very brittle ; affords water by calcination ; blackens.
then burns at the flame of the blowpipe, and leaves a white residuum which becomes
blue when it is calcined, after having been moistened with a drop of nitrate of cobalt.
It is a mellate of alumina, and consists of:
Mellitic acid
Alumina
Water -
Klaproth.
46
16
81
100
Wohler.
44-4
14-5
41-1
100-0
The honey-stone, like amber, belongs to the geological formation of lignite. Jt has
been hitherto found only at Artem in Thuringia ; at Luschitz, near Bilin in Bohemia ;
and near Walchow in Moravia.
HOP (HouUon, Fr. ; Hop/en^ Germ.) is the name of a well-known plant of the
natural family of Urticen, and of the Diaecia pentamlria of Linnaeus. The female flowers,
placed upon different plants from the male, grow in ovoid cones formed of oval leafy
scales, concave, imbricated, containing each at the base an ovary furnished with two
tubular open styles, and sharp pointed stigmata. The fruit of the hop is a small
rounded seed, slightly compressed, brownish coloured, enveloped in a scaly calyx, thin,
but solid, which contains, spread at its base, a granular yellow substance, appearing to
the eye like a fine dust, but in the microscope they seem to be round, yellow, transparent,
grains ; deeper coloured, the older the fruit. This secretion which constitutes the ose-
ml portion of the hop, has been examined in succession by Ives, Planche, Payen, and
Chevallier. A pretty full account of the results of their researches in treating of
the hop is given in the article Beer.
Number of Acres under the Cultivation of Hops in England^
1807
38.t2l8
1813
39.521
1819
51,014
I82.'>
46.718
1831
47.189
1K87
1
J«.3S3 .
isas
38,4H6
1814
40,S71
1820
60,148
18-26
50,471
1832
47,101
18^<4
U.045 '
1S09
38.367
1815
42,163
18'21
45.662
1827
49,486
1833
49,187
1839
52,»5 ;
1810
38,265
1816
44,-219
1822
43,766
1828
48,365
1834
61.273
1H40
44 805
1811
38,401
1817
46,493
H23
41,458
1829
46,135
1815
53,816
1841
45.76&
1812
88,700
1819
48,593
1824
43,449
1830
46,726 1
1836
55,422
1
Hop Duties of particular Districts,
Rochester ...
ranter bury ...
Siiisf>x - . . .
Worcester ...
Farnham ...
Kssex ....
North Clajs ...
Sundries . . - .
1841.
1842.
1841.
1845.
£ 9. d.
51,490 3 8
33,960 14 10
38.086 13 10
12,076 19 8
7,702 10 2
977 8 0
1.159 7 10
705 8 7
€ S. d.
68,812 4 7
81,019 13 5
4.V'«1 10 0
19,825 a 11
11,078 18 4
2,(m 19 11
1,724 2 7
2(3 14 3
€ «.
62,407 3
21,158 15
27.303 2
17.409 6
10,080 0
804 6
770 7
.389 16
d.
2
8
1
4
4
2
0
5
£ 9. d.
51,056 6 0
86.501 6 3
54304 5 11
9.091 1 9
5.425 5 11
I 1,534 17 4
146,159 1 7
169.776 6 0
140,322 17
3
158,003 12 3
HOP.
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HORN.
Annual Amount of Hop Duty,
Y—n.
ABMMIBt«
T«tn.
Amoimt
Yarn.
AmooBk
V-..
Amoaiit*
1
Y«ai.|
Anmnit*
Yens.
1
£
£
€
£
£
£
1711
43.437
1735
42,745
1759
42,115
1783
75,716
1807
100.071
1830
88047
1712
30,278
1736
46,488
1760
117,998
1784
94,359
1808
361.069
1831
174.^4
1713
23,018
1737
56,492
1761
79,776
1785
112,684
1809
63,469
1839
l39.o!«
1714
14,457
1738
66J»75
1762
79,295
1786
95.973
IRIO
73.514
IBSS
156 9ff*
1715
44,975
1789
70,742
1763
88,316
4787
42,227
1811
167.095
1834
189.713
1716
•20,354
1740
37,875
1764
17,178
1788
143.168
1813
30,618
18^5
935:307
1717
64,669
1741
65,298
1765
73,778
1789
104,063
1813
131,489
1836
SQJ31
1718
15,006
1742
45,550
1766
116.445
1790
10G.841
1814
140,909
1837
I7S,ST««
1719
90.317
1743
61«07a
1767
85,997
1791
90,050
1816
123,878
1838
ni,a«
1720
38,169
1744
46,708
1768
114,002
1792
162,112
1816
46.309
IK39
li»%yi7
1721
61,362
1745
84,636
1769
16,901
1793
93.619
1817
66r'i99
1840
3M&1
1722
49,443
1746
91,879
1770
101,131
1794
303,063
1818
199,405
1841
146,1^
1723
80,279
1747
62,993
1771
33.143
1795
82.342 '
1819
943.476
1849
l^TTS
1724
61.871
1748
87,155
1779
102.650
1796
76,993
1820
138.330
1443
133 4t^l
1725
66.526
1749
36,806
1773
45,947
1797
l.'.7.458
1821
154.609
1M44
140^123
I7t6
80,031
1760
72,138
1774
138^7
1798
66.033
1883
303.794
1845
ISft.O''*
1727
69,409
1751
73.954
1775
41,697
1799
73,379
1823
96.068
1846
949 9S
1788
41,494
1752
82,163
1776
135,691
1800
72,928
1834
148,839
1847
2l^.MI5
1729
48^41
1753
91,814
1777
43,681
1801
341.227
1885
34,317
1848
919.416
1730
44,419
1754
102.018
1778
169,891
1809
15,463
1836
969.331
1849
T9J?«l
1731
32.600
1755
82,167
1779
65,800
1R03
199.305
1827
140,84H
IftfiO
933.393
1732
35,135
1766
48,106
1780
13-2,734
1804
177.617
1828
172,027
1851
IMHUA
1733
70.215
1757
69,713
1781
190,218
1805
83,904
1889
38.396
185-i
940.000
1734
37,716
1768
72,896
1783
14,885
1806
153,103
Pounds weight of haps which paid duty, which were exported on drawbacks or frtt cf
duty, and retained for home consumption.
Yean.
Charged with Duty.
Exported on Draw-
back or free of Doty.
Retained for HoBM
Contamptioa.
Itw.
Ibfl.
lbs.
1842 - - - -
85,432,142
662,832
34,769,310
1843 - - - -
27,862,725
292,709
27,570,016
1844 - - - -
29,285,004
153,849
29,131,245
1845 - - - -
82,974,749
151,211
32,823,538
1846 - - - -
60,704.025
448,497
50,255,528
1847 - . - -
45,134,365
457,061
44,677,304
1848 - - - .
44,343,985
i 57,029
43,986,956
1849 - - - -
16,650,915
274,811
16,376,104
1850 - - - -
48,537,669
270,611
48,267,158
1851 - - - -
27,042,996
904,090
26.138,906
1852 - - - -
51,102,494
955,855
50,146,639
1853 - - . -
31,761,693
802,103
30,949,590
1854 - . - -
9,877,126
585,168
9,291.958
i865 - - • -
83,221,004
852.856
8->.368,448
1856 - - - -
55,868,624
1,565,249
54.303,375
1857 - - - -
47,717,561
1,450,104
46,267,457
1868 - - - .
53,125,100
4,177,250
48,947,850
HORDEINE is the name given by Proust to the peculiar starchy matter of barley.
It seems to be a mixture of the starch, lignine, and husks, which constitute barley
meal. See Beeb.
HORN (Eng. and Germ ; Sois, Come^TT.), particularly of oxen, cows, goats, and
sheep, is a sul^tance soft, tough, semi-transparent, and susceptible of being cut and
pressed into a variety of forms ; it is this property that distinguishes it from bone.
Turtle or tortoise shell seems to be of a nature similar to horn, but instead of being
of a uniform colour, it is variegated with spots. See Tortoise Shell.
Mr. Aikin (7Van«. Soc. of Arts) remarks, '*In the English language we have only
one word to express two quite different substances ; namely, the branched bony horns
of the stag genus, and the simple laminated horns of the ox genos, and other kindred
genera. The bony horns are called in the French bois, from their likeness to the
branch of a tree : they are annually renewed. The other bom to which the French
appropriate the term corns, is found on the ox, the antelope, the goat, and sheep kindsu"
The valuable properties of horn render it susceptible of being employed in a variety
of works fit for the turner, snuff-box, and comb maker. The means of softening
the horn need not be described, as it is well known to be by heat ; bat those of cutting,
polishing, and soldering it, so as to make plates of large dimensions, suitable to
form a variety of articles, may be detailed. The kind of horn to be preferred is
HORN. 463
tliat of goats ind 8beep« from its being whiter and more transparent than the horn
of any other animals. When horn is wanted in sheets or plates, it mast he steeped
in water, in order to separate the pith from the kernel, for aboat fifteen days in
summer, and a month in winter ; and after it is soaked, it most be taken oat by one
end, well shaken and rubbed in order to get off the pith ; after which it must be pat
lor half an hoar into boiling water, then taken oat, and the surface sawed eyen
lengthways ; it mast again be pat into the boiling water to soften it, so as to render it
ca|table of separating ; then, with the help of a small iron chisel, it can be diyided into
sheets or leaves. The thick pieces will form three leaves, those which are thin will
form only two, whilst young horn, which is only one quarter of an inch thick, will
form only one. These plates or leaves most again be pat into boiling water, and
when they are sofficiently soft, they mast be scraped with a sharp cutting instrument,
to render those parts that are thick even and uniform ; they must be put once more
into the boiling water, and finally carried to the press.
At the bottom of the press employed, there most be a strong block, in which is
formed a cavity, of nine inches square, and of a proportionate depth ; the sheets of horn
are to be laid within this cavity, in the following manner: at the bottom, first a sheet of
hot iron, upon this a sheet of horn, next again a sheet of hot iron, and so on, taking
care to place at the top a plate of iron even with the last The press must then be
screwed down tight.
There is a more expeditions process, at least in part, for reducing the horn into
sheets, when it is wanted very even. After having sawed it with a very fine and
sharp saw, the pieces must be put into a copper made on purpose, and there boiled
until sufficiently soft, so as to be able to be split with pincers ; the sheets of horn must
then be put in the press where they are to be placed in a strong vice, the chaps of
which are of iron had larger than the sheets of horn, and the vice must be screwed as
quick and tight as possible ; let them cool in the press or vice, or it is as well to
plunge the whole into cold water. The last mode is preferable, because the horn
does not shrink in cooling. Now draw out the leaves of horn, and introduce other
horn to undergo the same process. The horn so enlarged in pressing, is to be
submitted to the action of the saw, which oaght to be set in an iron fhtme, if the horn
is wanted to be cat with advantage, in sheets of any desired thickness, which cannot
be done without adopting this mode. The thin sheets thus produced must be kept
constantly very warm between plates of hot iron to preserve their softness ; every
leaf being loaded with a weight heavy enough to prevent its warping. To join the
edges of these pieces of horn together, it is necessary to provide strong iron moulds
suited to the shape of the article wanted, and to place the pieces in contact with
copper-plates or with polished metal surfaces against them ; when this is done, the
whole is to be put into a vice and screwed up tight, then plunged into boiling water,
and after some time it is to be removed from thence and immersed in cold water. The
edges of the horn will be thus made to cement together and become perfectly united.
To complete the polish of the horn, the surfoce must be rubbed with the subnitrate
of bismuth by the palm of the hand. The process is short, and has this advantage, that
it makes the horn dry promptly.
When it is wished to spot the horn in imitation of tortoise shell, metallic solutions
must be employed as follows : — To spot it red, a solution of gold in aqua regis must
be employed ; to spot it black, a solution of silver in nitric acid must b^ used } and
for brown, a hot solution of mercury in nitric acid. The right side of Uie horn must
be impregnated with these solutions, and they will assume the colours intended. The
brown spots can be produced on the horn by means of a paste made of red lead, with
a solution of potash, which must be put in patches on the horn, and subjected some
time to the action of heat The deepness of the brown shades depends upon the
quantity of potash used in the paste, and the length of time the mixture lies on the
horn. A decoction of Brazil wood, or a solution of indigo, in sulphuric acid, or a de-
coction of saffron and Barbary wood may also be used. After having employed these
materials, the horn may be left for half a day in a strong solution of vinegar and alum.
In France, Holland, and Austria, the comb-maker and horn-turners use the clip-
pings of faom-^which are of a whitish yellow — and tortoise-shell skins, out of which
they make snuff-boxes, powder-horns, and many curious and handsome things. They
first soften the horn and shell in boiling water, so as to be able to submit them to the
press in iron moulds, and by means of heat they form them into one mass. The degree
of heat necessary to join the bom clippings mast be stronger than that for shell skins,
and it can only be found out by experience. The heat must not however, be too
great, for fear of scorching the horn or shelL Considerable care is required in
these operations, not to touch the horn with the fingers, or with any greasy body,
because the grease will prevent the perfect joining. Wooden instruments should
be used to move them, while they are at the fire, and for carrying them to the moidds.
In making a ring of horn for bell-pulls, &c., the required piece is to be first cutout
464 HOBSE CHESTNUT.
in the flat of its proper dimeii«0P5,«iidii€ariy in the diapeof a liorw iliof ; it s Aa
pressed in a pair of dies to gire its surface the desired pattern ; bat previovs to the pres-
sure, both the piece of horn and the dies are to be heated ; the pieceof horn is to be
introduced between the dies, squeezed in a Tice, and when cold, the iayrfiua or
pattern vill be fixed npon the horn. One particular condition, howcTer, is to be ob-
serred in the construction of the dies, for forming a ring. They are to be so asade
that the open ends of the horse-shoe piece of horn, after being pressed, shall hare at
one end a nib, and at the other a recess of a doTctailed form, corresponding to c&rh
other ; and the second operation in forming this ring of horn is to heat it, and place u
in another pair of dies, which shall bring its open ends together, and cause the dore-
tailed joints to be locked fast into each other, which completes the ring^ and leaYes no
appearance of the junction.
In forming the handles of table kniyes and forks, or other things whicb require to be
made of two pieces, each of the two pieces or sides of the handle is formed in a sepa-
rate pair of dies ; the one piece is made with a countei^^nnk grooTC akmg each ade,
and the other piece with corresponding leaves or projecting edges. When these twn
pieces are formed, by first being cut out of the fiat horn, then pressed in the dies
in a heated state, for the purpose of giTing the pattern, the two pieces are again
heated and put together, the leaves or edges of the one piece dropping into the
counter-sunk grooTcs of the other piece, and being introduced between another pair of
heated dies, the joints are pressed together and the two pieces formed into one handle.
In making the knobs for drawers which have metal stems or pins to fasten them into
the Aimiture, the face of the knob is to be first made in a die, as aboye described, and
then the back part of the knob with a hole in it ; a metal disc plate of iron is next pro-
vided, in which the metal stem or screw pin is fixed, and the stem being passed throogfa
the aperture in the back piece, and the two, that is, the back and front pieces of horn
put together, they are then heated and pressed in dies as above described ; the edge of
the back piece falling into the counter-sunk groove of the firont piece, while by the
heat they are perfecUy cemented together.
Mr. J. James has contrived a method of opening up the horns of cattle, by which he
avoids the risk of scorching or frizzling, which is apt to happen in heating them over an
open fire. He takes a solid block of iron pierced with a conical hole, which is fitted
with a conical iron plug, heats them in a stove to the temperature of melting lead, and
having previously cut up the horn lengthwise on one side with a saw, he inserts its
narrow end into the hole, and drives the plug into it with a mallet. By the heat of
the irons, the horn gets so softened in the course of about a minute, as to bear flatting
out in the usual way.
Importation of Hortu, 1857.
Horns and Tips and pieces thereof.
Hanse towns - - - .
United States - - - ' -
Brazil - - - - -
Uruguay - . - .
Buenos Ayres - - . -
British possessions in South Africa
Bijtish East Indies
Australia ....
Other parts - - - .
3,938 £154,233
Exportation o/Homa, 1857.
Qttantitj. Value.
Horns, tips, and pieces of Horn - - cwt 1327 £51,986
HORNBEAM. The Carpinua betulus, sometimes called the yoke-elm. It is
a stringy and tough wood which g^ows in some parts of Europe, and which is imported
from America. It is used by millwrights for the cogs of wheels, also for skittles, and
for mallets.
HORN SILVER, or Luna Cornea. Fused chloride of silver. Both these names
were given by the alchemists to this preparation. It is found native. See Silveb,
Ores of.
HORNSTONE. A variety of quartz, resembling flint, but more brittle, and, break-
ing with a more splintery fracture. It sometimes occurs imbedded in limestone.
See Chert.
HORSE CHESTNUT. (Marronnier D*Inde,Fr,i Gemeine Eosakastame^Qerm.)
The wood of this well known tree is used by the Tunbridge turner. It is only em«
ployed for some large varnished works.
Qtuntity.
Value.
tons 237
£21,626
791
29,860
243
10,327
234
9,945
289
12,283
155
5,913
1,592
48,039
202
5,086
195
11,154
HORSE POWER.
466
HORSE POWER, In steam engines, is estimated by Mr. Watt at 32,000 pounds
avoirdapois lifted one foot high per minate, for one horse. M. D*Aubui8son, from an
examination of the work done .by horses in the whims, or gigs (machines d molottes) for
raising ore from the mines at Freyberg, the horses being of average size and strength,
has eonclnded that the nseAil effect of a horse yoked during eight hoars, by tvo relays
of (bar hours each, in a manege or mill coarse, may be estimated at 40 kilogrammes
raised I mdter per second ; which is nearly 16,440 pounds raised one foot per minute ;
being very nearly one half of Mr. Watt's liberal estimates for the horse power of his
6team engines.
Frederick William Simms, Bl. Inst C £., adopted some pecnliar conditions of
work on which he was engaged to determine the yalne of korwe power. He had to
make a tunnel for the South Eastern Railway. This tunnel was driven in the middle
bed of the lower green-sand, between which and the surface of the ground is interposed
only the upper bed of the same stratum ; but in sinking the eleyen shafts for the work,
it was found that at the level of the top of the tunnel, the ground assumed the character
of a quicksand, saturated with water, in such quantity that it could not be reduced by
manual labour. Under these circumstances horse gins were erected for drawing
the water by barrels, containing one hundred gallons each, weighing when full
about 1310 lbs.
The engineer's intention was, to drive simultaneously from these shafts, in the direc-
tion of the tunnel, an adit or heading to carry off the water ; but the earth, which was
sand mixed with fine particles of blue clay, was so filled with water as to become a
mass of semifluid mud ; great exertions were therefore necessary to overcome the water,
without erecting pumps. At first this was accomplished by making each horse work
for 12 hours and then for 8 hours per day, allowing one hour for food and rest : as
the water increased it became necessary to work night and day, and the time of each
horse's working was reduced generally to 6 hours, and sometimes to 3 hours. As all
the horses were hired at the rate of seven shillings per day, the engineer, who had
the direction of the works, ordered a daily register to be kept of the actual work done
by each horse, for the double purpose of ascertaining whether they all performed their
duty, and also hoping to collect a body of facts relative to horse power which might
be useful hereafter.
Mr. Simms gives as a proposition, " that the proper estimate of horse power would
be that which measures the weight that a horse would draw up out of a well ; the animal
acting by a horizontal line of traction turned into the vertical direction by a simple
pulley, whose friction should be reduced as much as possible-" He states that the
manner in which the work was performed, necessarily approached very nearly to these
conditions ; and after giving the principal dimensions of the horse gins, he analyses
each set of experiments, and by taking the mean of those, against which no objections
could be urged, he arrives at the following results : —
The power of a horse for 8 hours a 23,412 lbs. raised 1 foot high in one minute,
da dou 6 » 24,360 do.
do. do. 4^ » 27,056 do.
do. do. 3 -B 32,943 do.
Of these results, he thinks the experiments for 6 hours and for 3 hours alone should
be adopted as practical guides, all the others being in some degree objectionable.
As a means of comparison, the following table of estimates of horse power is given : —
Pounds raffled
Name.
1 foot high
in a minate.
HouTfofvork.
Authority.
Bonlton and Watt -
32,000
8
Robinson's Mech. Phil, ii. 145.
Tredgold
27,500
8
Tredgold on Railroads, p. 69.
Besaguliers ...
44,000
8 •
Ditto . . . -
27,500
Not Stated
Dr. Gregory's Mathematics
Sanssnre ...
34,020
8
1 for Practical Men, p. 183.
More, for Society of Arts
21,120
Not stated
Smeaton. ...
22,000
Not stated
J
These are much higher results than the average of his experiments, and would
more nearly accord with the extremes obtained by him; but under such excessive
fatigue, the horses were speedily exhausted, and died rapidly. Nearly one hundred
horses were employed ; they were of good quality ; their average height was 15 hands
\ inch, and their weight about lOj cwte., and they cost from 20Z. to 40/. each. They
had as much com as they could eat, and were well attended to.
The total quantity of work done by the horses, and its cost, was as nnder: —
Vol. II. II H
466 HORSE POWER.
Registered quantity of water drawn 104 feet, the aTerage height,! .^^ .,_
28,220,800 gaUong -.-J iar»,S35
Dow earth, 8,500 yds. 1 ton 6 cwt. per yard ... 4,550
Total weight drawn to the surface - - 133,955
Total cost of horse labour, including a boy to driye each horse, 1,5852. I5«. 3dL, or
S'86</. per ton the average height of 104 ft
Mr. Palmer made some experiments on the amount of work performed by horses
tracking boats on canals. On the upper end of the mast of the boat a pulley was hmg ;
over this the towing rope was passed, with the means of suspending to its extremity
^Ten weights, so as exactly to balance the power exerted by the horse.
The results arrived at by these means were so various, that he could not dedooe
any average conclusions, as the power exerted varied between 30 lbs. and 120 Dml,
the power diminishing as the speed was increased. He thought that 2| miles was too
high an average estimate, and that it should not exceed 2 miles per hour, although
in all estimates of horse power, the speed was considered to be at an ayerage of 2}
miles per hour, and all experiments were reduced to that standard.
Mr. Hawkins, some years since, had made numerous inquiries respecting the woik
done by horses in drawing upon common turnpike roads, and found that four good
horses could draw an ordinary stage-coach with its complement of passengers,
at the rate of ten miles an hour ; that if they ran stages 10 miles in the hour,
the horses must rest one day in each week ; that good horses, so worked, would last
only five years, each horse drawing about half a ton. He had been informed by
waggoners, that good horses would walk at the rate of 2^ miles per hour, for twelve
hours out of twenty-four, making 30 miles a day ; and that they would continue to do
such work day by day, each horse drawing one ton, for many years, provided they
had not been worked hard when young.
It is desirable to know the average speed at which the different rates of work had
been performed ; this was essential in order to found any calculation upon the resahi
given. Coach proprietors calculated that at a speed of 10 miles per hour, a horse was
required for every mile going and returning, so that one horse was kept for every
mile of road. Now supposing a four-horse coach, with an average load, to weigh 2
tons, the load for each horse was 10 cwts. ; whereas in the case of a horse drawing a
cart, the gross load frequently amounted to 2 tons, but the speed was reduced to 2|
miles per hour, at which pace he conceived that 16 miles per day might be considered
a fair day's work ; this therefore was double the distance with four times the load, or
eight times the coach work, but with a heavier horse.
The law that the quantity of work done was as the square root of the velocuty,— or
as the cube root of the velocity, in equal times, — is confined to work upon caaals^ or
bodies moving through the water.
Mr. Rennie had tried some experiments on the force of traction of the boats on the
Grand Junction Canal. The towing rope is attached to a dynamometer, which had
previously been attested by weights.
The horse, although urged at first starting, was afterwards allowed to &U into his
natural speed, which was 2J miles per hour on the average of 20 miles. The maxi-
mum speed was 4 miles, and the minimum 2 miles, per hour. The dynamometer
indicated an average of 108 lbs., which was capable of overcoming the resistance of
the loaded barge of 25 tons, being in the ratio of 15*00. The weight of the horse was
about 11 cwts.
He also tried many experiments upon a fast boat, lent to him in 1833 by the late
Colonel Page. These experiments were principally made in order to ascertain the
comparative resistance of vessels moving through water at different velocities, and
the Grand Junction Canal afforded a convenient opportunity of undertaking them.
The boat was 70 feet in length, 4 feet in breadth, and drew 9 inches of water.
The traction indicated by the dynamometer the following resistance: —
Mili-t per hour. lbs.
At 2^ the resistance was 20
3 „ 27
3^ „ 30
4 „ 50
4J „ 60
6 „ 70 to 75
One horse was employed in these expe-
riments.
Miles per hour. lbs.
At 6 the reustance was 97 to 214
7
»
250
8
»>
336
9-69
f»
411
10
tf
375
Hi
•»
392
Average 336
Two horses were employed in these expe-
riments.
HORSESHOES.
467
Stakes were fixed near tlie margin of the canal, so as to ascertain the rise and fall
of the waye caused bj the boat in passing ; and it was observed that when a boat
passed with a Teloeitj of ftom 4 to 6 miles per hoar, the rise of the wave was 5 inches,
and the £U1 5 inches, making a wave of 10 inches in depth ; and when the velocity
was 11^ miles, the rise was reduced to SJ inches, and the fall to 2| inches.
Great difference existed in the power of horses, their weights and stnicture ; and
the large dray horses used by Messrs. Barclay, Perkins, and Co. did a full average
dnty as assumed by Boulton and Watt ; but considering the average power of strong
and weak animals, he had adopted 22,000 lbs. raised 1 foot high as the standard^
mach, however, depended on the nature of the work performed.
Mr. Davidson has given the following statement of the work performed by a Lon-
don brewer's hone per day ; the cost of f^ed and of wear and tear per horse per annum
being derived fh)m actual experience among a large number of horses at Messrs.
Truman, Hanbury, and Co.'& brewery. The feed, &&, is supposed to have cost the
same per quarter per truss, &c., each year.
Tean.
Poundt Wriffht
drmwn 61 Mflet
per Hofse per
Pounds Welsbt
drawn 6^ Milet
per Hone return-
ing per Day.
Average Ponnds
WeisTit drawn
IS Miles per
Horse per Day.
3,342 lbs.
3,389
3,377
3,513
3,803
3,530
3,501
Cost of Feed
and Straw per
Horse per
Annum.
Difft^enco por
Horte of Ilnrsi s
bought nn.i suld
per Annum.
1835
1836
1837
1838
1839
1840
1841
1842
Total
5,148 lbs.
6,072
5.057
5,287
6,786
5,311
5,263
1,716 lbs
1,767
1,698
1,740
1,820
1,750
1,740
£43 2 7
43 16 6
41 18 0
42 9 11
46 11 7
45 0 1
47 0 9
£10 0 3
9 18 0
9 15 9
9 7 1
7 17 11
10 16 11
10 8 0
36,924
12,171
24,455
309 19 5
68 3 11
Average 7
1 yrs. nearly
} 5,275
1,738
3,506
44 5 7
9 14 10
Mr. Beardraore mentions a case which occurred in a work near Plymouth, which
be believed would give the fisiir value of the work actually performed daily by a horse
Ibr a considerable period.
A quarry-waggon, weighing 2^ tons, carrying an average load of stone of 5] tons,
was drawn by one horse along a railway 960 feet in length, 260 of it being level, and
the remaining 700 fieet having an inclination of 1 in 138. During 48 working days
the number of trips was 1,302, or an average of 27*1 trips each day ; the time of per-
forming each trip was 4 minutes, or at a speed of 2*72 miles per hour ; and the
total weight drawn, including that of the waggons, was 23,959,600 lbs.
Repeated experiments proved, that upon the incline of 1 in 138 the waggons in
their ordinary working state would just remain stationary ; the fViction was therefore
assumed to be 16-2 Vm. per ton ; by calculation it was found that the horse raised
89,320 lbs. 1 foot high' per minute during the 8 working hours each day : the useful
effect, or net amount of stone carried, being 21,738 lbs. raised 1 foot high per minute.
This difference between the work done and the useful effect arose from the necessary
strength and weight of the waggons.
The animal employed was a common Devonshire cart-horse, 8 years old, 15 hands
high, and weighed 10} cwts ; he continued doing the same work throughout a whole
summer, remaining in good condition ; but a lighter horse was found unequal to it
HORSESHOES. The ordinary method of making these is well known. There
has however been lately introduced with much success a machine for making horse-
shoes. One of these machines has been erected at Chillington Ironworks, Wolver-
hampton, by the Inventor, Mr. Henry Burden, of Troy, New York. As early as
1835 he took out a patent for a machine for making horseshoes, which he improved
upon in 1843, and this was turned to practical account by the production of a con-
siderable number of horseshoes. The present machine, however, which was patented
in 1857, is entirely different from the mrmer ones, and is a very remarkable piece of
mechanism. In the previous machines the piece of iron bar of which the shoe was to
be made was rolled into shape before being bent, and the pressure of the rollers being
in the direction of its lengto, the bar, when it was pressed, was naturally rather ex-
tended in length than width, and the widening which is required at the crown of the
shoe was not properly effected. By the present plan the bar, after being heated,
enters the machine by a feeding apparatus, a piece of the required length is cut off,
and, by a stroke from a piece of steel, shaped like the inside of a horseshoe, is bent,
and falls npon a die on a wheel beneath, corresponding to one on a C;ylinder above,,
H H 2
468 HOSIERY.
and thus acquires by pressare the desired shape, two lateral s6iken at the flnoe
moment hitting the extremities, or heels, of the shoe, and driving them inwards into
the required shape. Thence it passes between another pair of dies, where it is stamped,
and by an ingenious arrangement is flattened from the curled shape which the wbed
gives It as it falls at the mouth of the machine. The shoes thus made are remarkaUe
for their exactness in shape and in the position of the holes — a most important point
with regard to the safety of horses* feet ; and they can be produced, when the iM^hin*
is in proper order, at the rate of 60 per minute, which is more than two men can
forge in a day, and the superiority over shoes forged by hand is very striking. As
the bar is bent before being pressed in the die, the pressure at the crown is in the
direction of the width, and hence the widening is readily effected.
HOSIERY. (Bwmeterie, Fr. ; Strump/u>eberei, Germ.) The ttoeking frame, whkk
is the great implement of this business, though it appears at first sight to be a compli>
cated machine, consists merely of a repetition of parts easily understood, with a mode-
rate degree of attention, provided an accurate conception is first formed of the natare
of the hosiery fabric. This texture is totally different from the rectangolar decDasatioa
which constitutes cloth, as the slightest inspection of a stocking will show ; for this,
instead of having two distinct systems of thread, like the warp and the weft, which are
woven together by crossing each other at right aogles, the whole piece is composed
of a single thread united or looped together in a peculiar manner, which is edkd
stocking-stitch, and sometimes chain-work.
This is best explained by the view in Fig, 963. A single thread ia formed into
a number of loops or waves, by arranging it
^^^ ' R « oYcr a number of parallel needles, as shown at
R ; these are retained or kept in the form of
loops or waves, by being drawn or looped
through similar loops or waves formed by the
thread of the preceding course of the work, si.
The &bric thus formed by the union of a num-
ber of loops is easily unravelled, because the
stability of the whole piece depends upon the
ultimate fastening of the first end of the thread ;
and if this is undone, the loops formed by that
end will open^ and release the subsequent loops
one at a time, until the whole is imravelled, and drawn out into the single thread firom
which it was made. In the same manner, if a thread in a stocking piece fiuls, or
breaks at any part, or drops a stitch, as it is called, it immediately produces a hole,
and the extension of the rest can only be prevented by fastening Uie end. It should
be observed that there are many different fabrics of stocking stitch for various kinds
of ornamental hosiery, and as each requires a different kind of frame or machine to pro-
duce it, we should greatly exceed our limits to enter into a detailed description of thera
alL That species which we have represented in y!^. 963 is the common stocking-stitch
used for plain hosiery, and is formed by the machine called the common stocking-fraoMi,
which is the groundwork of all the others. The operation, as we see, consists in draw-
ing the loop of a thread successively through a series of other loops, so long as the
work is continued, as is very plainly shown for one stitch in^i^. 964.
There is a great variety of different fiames in use for producing various ornamental
kinds of hosiery. The first, which forms the foundation of the whole, is that for knit-
ting plain hosiery, or the common stocking-frame.
Of this valuable machine, the invention of Mr. Lee of Cambridge, a side elevattoo is
given in^. 965, with the essential parts. The fhuning is supported by four upright
posts, generally of oak, ash, or other hard wood. Two of these posts appear at a a, and
the connecting cross rails are at c c. At b is a small additional piece of framing, which
supports the hosier's seat The iron-work of the machine is bolted or screw^ to the
upper rails of the framework, and consists of two parts. The first rests upon a aole of
polished iron, which appears at d, and to which a great part of the machinery is
attached. The upper part, which is generally called the carriage, runs upon the iron
sole at D, and is supported by four small wheels or trucks, as they are called by the
workmen. At the upper part of the back standard of iron are joints, one of which
appears at q ; and to these is fitted a frame, one side of which is seen extending to h.
By means of these joints the end at h may be depressed by the hosier's hand, and it
returns, when relieved, by the operation of a strong spring of tempered steel, acting
between a cross bar in the frame, and another below. The action of this spring is
very apparent in Jig, 966. In the fVont of the frune, immediately opposite to where
the hosier sits, are placed the needles which forms the loops. These needles, or rather
hooks, are more or less numerous, according to the coarseness or fineness of the
stocking; and this, although unavoidable, proves a very considerable abatement of
the value of a stocking-frame. In almost every other machine (for example those em-
HOSIERY.
469
965
plojed in spuming or weaving), it is easy to adapt any one either to work ooaraer
or finer work, as it may be wanted. Bat in the manofactare of hosiery, a frame
once finished, is limited for ever in its operation to the same qualitjr of work, with
this exception, that by changing the stn^ the work may be made a little more dense
or flimsy; but no alteration in
the size or quantity of loops can |^
take place. Hence where the
mannfiictare is extensiyely pro-
secuted, many frames may be
thrown idle by erery yicissitnde
of demand; and where a poor
mechanic does purchase his own
frame he is for ever limited to
the same kind of work. The
gauge, as it is called, of a stock-
ing.frame is regulated by the
number of loops contained in
three inches of breadth, and va-
ries very much; the coarsest
frames in common use being
about what are termed Four-
teens, and the finest employed
in great extent abont Forties.
The needles are of iron wire,
the manofiticture of which is
very simple ; but long practice
In the art is found necessary be-
fore a needle>maker acquires the
dexterity which will enable him
both to execute his work well,
and in sufficient quantity to render his labour productive.
The process of making the needles is as follows: — Good sound iron wire, of a proper
fineness, is to be selected ; that which is liable to split or splinter, either in filing,
punching, or bending, beinp^ totally unfit for the purpose. The wire is first to be cut
into proper lengths, accordmg to die fineness of the frame for which the needles are
designed, coarse needles being considerably longer than fine ones. When a sufficient
number (generally some thousands) have been cut, the wire mast be softened as much
as possible. This is done by laying them in rows in a fiat iron box, about an inch
deep, with a close cover ; the box being filled with charcoal between the strata of wires.
This box, being placed upon a moderate fire, is gradually heated until both the wires and
charcoal have received a moderate red heat, because, were the heat increased to what
smiths term the white heat, the wire would be rendered totally unfit for the subseqoent
processes which it has to undergo, both in finishing and working. When the box has
been sufficiently heated, it may be taken from the fire, and placed among hot ashes
until both ashes and box have gradually cooled ; for the slower the wires cool, the
softer and easier wrought they will be. When perfectly cool, the next process is to
punch a longitudinal groove m the stem of every needle, which receives the point or
barb^ when depressed. This Is done by means of a small en^no worked by the power
of a screw and lever. The construction of these engines is various ; but a profile
elevation of one of the most simple and commonly
used will be found in fig. 966. It consists of two
very strong pieces of malleable iron, represented
at A and c, and these two pieces are connected by
a strong well -fitted joint at b. The lower piece,
or sole of the engine at c, is screwed down by bolts
to a strong board or table, and the upper piece a
will then rise or sink at pleasure, upon the joint b.
In order that a may be very steady in rising and
sinking, which is indispensable to its correct oper-
ation, a strong bridle of iron, which is shown in
section at e, is added to confine it, and direct its
motion. In the upper part of this bridle is a female screw, through which the forcing
screw passes, which is turned by the handle or lever d. To the sole of the engine c
is fixed a bolster of tempered steel, with a small groove to receive the wire which is to be
punched ; and in the upper or moving part a, is a sharp chisel, which descends exactly
into the groove, when a is depressed by the screw. These are represented at f, and
above h. At o is a strong spring, which forces up the chisel when the pressure of
H H 3
966
470
HOSIEET.
the (crew u rMioved. The appcorancB of tbc groore, vhan tli . _
vlll b« rendered familiar bjr uupecliDg fis- 973, p. 171. Wheii the pvocbing ia
fioiihed, the irirei are to b« brought to ■ fine ■mooth ptust bj filing nd bnTtushiiig,
the tatter of vhich should be Ter; complete!; done, la, beiidei poliihiiig tbe wire, it
teadi greatlf to restore that spring and elasticitj which has be«B remoTed by tbe pre-
Tious operation of softeQing. The vire is next to be bent, in order to fona the hook
or barb ; and this is done with a small piece of tin plate bent doable, which rtceiTCa
the point of the wire, and by its breadth regulates the length of the baA. The item
of the needle is now flattened with a small hammer, to prerent it from tanung is lb«
tin socket in which it ii afterwards to be cast ; and the ptunt c^ the harb being n, little
cunred b; a pair of small pif en, the needle is completed.
In order to fit the needles for the frame, thej are now cast into the tin iockas or leads
as thejr are called by the workman; and this is done by placing the needles in an iron
mould, which opens and shnls by means t^ a joint, and pouring in the tin while in a
state of fusion. In common operations, two needles srt ca&t into the same lockeL The
form of (he needle, when complete and fitted to its place in the frame, will be seen in
-.. M 967, which is a profile Hwtioa
» /x'j^ Qf the needle-b«r exhibiting one
needle. In this figure a tectioo of
the pressotc ii ieprcsent«l at r;
the needle appears at a, and the
■Dckel ac level at k. At 8, b a
aectioD of tbe needle-bar. oo the
fore part of which is a tmail plate
of iron called a verge, to regolate the position of the needles. When placed apoo
the bar resting against the verge, another plate of Iron, generally lined with soft leather,
ia screwed down npon tbe sockets or leads, in order to keep them all &iL This pialc
and the screw appear at i. When tbe presaer at r ii forced down npon tbe barh, this
sink* into the groore of the Stem, and the needle is sbnt ; when the presacT ritea, the
barb opens again by its own elasticity.
The needles or hooks being all properlj fitted, the next part of the stocking-frame to
which attention ought to be paid, is the machinery for forming the loop* ; and this con-
liets of two parts. The first of these, which ainka between every second oi alternate
needle, Is represented at o, fig. 965, and is one of the most important parts of the whole
machine. It consists of two moving parts ; the first being a snccession of horiiootal
leveri moving upon a common centre, and colled jacks, a term applied to vibrating le^en
in various kinds of machinery as well as the stocking-frame. One only of lhe«e jacks
can be represented in the profile jfi;, 965 ; but the whole are distinctly shown in a bori-
lontal position vajiy. 968 ; and a profile upon a very enlarged scale is given io^. 969.
Thejacltsbownin^^. 963,exleiidebo[izontallj ftouo to i, and tbe centre of motion
-E^^
IS at B. On the front, or ngbt hand of the jack at o, is a joint anspcnding a vor
thm plate of polished iron, which is termed a tinker. One of these jacka and sinken n
allotted for every second or alternate needle. The form of the sinker will appear at a.
HOSIERY.
471
fig. 969 ; and in order that all may be exactly uniform in shape, they are cut out and
finished between two stout pieces of iron, which serve as moulds or gauges to direct the
firame*smith. The other end of the jack at i, is tapered to a point ; and when the jacks
are in their horiaontal position, they are secured by small iron springs, one of which is
represented at i,^. 965, each spring having a small obtuse-angled notch to receive the
point of the jack, against which it presses by its own elasticity. In fig, 969, the centre
is at B, the pointed tail is omitted for want of room, the jomt is at o, and the throat
of the sinker, which forms the loop, is at a. The standards at r, upon which the jack
moves, are called combs, and consist of pieces of flat smooth brass, parallel to, and
equidistant from each other. The cross-bar b, which contains the whole, is of iron,
with a perpendicnlar edge or rim on each side, leaving a vacancy between them, or a
space to receive the bottom part or tails of the combs. The combs are then placed in
the bar, with a flat piece of brass called a countercomb, between each, to ascertain
and preserve their distances from each other. These conntercombs are exactly of
the same shape as the combs, but have no tails. When both combs and conntercombs
are placed in the bar, it is luted with clay so as to form a mould, into which is
poured a sufiieient quantity of melted tin. When the tin has had time to cool, the
conntercomhe having no tails are easily taken out, and the combs remain well fastened
and secured by the tin, which has been fused entirely round them. Thus they form a
SQCcession of standards for the jacks ; and a hole being drilled through each jack and
each comb, one polished wire put through serves as a common centre for the whole.
The jack sinkers being only used for every alternate or second needle, in order to
complete this part of the apparatus, a second set of sinkers is employed. These are, in
form and shape, every way the same as the jack sinkers, but they are jointed at the top
into pieces of tin, ail of which are screwed to the sinker bar, "s^fig, 965 ; and thus a
sinker of each kind descends between the needles alternately. By these sinkers the
loops are formed upon all the needles, and the reason of two sets different in operation
being employed, will be assigned in describing the mode of working the frame. The
presser of the operation, of which something has already been said, appears at f ; and
of the two arms which support and ^ive motion to it, one appears very plainly at E,its
centre of motion being at a Tlie circular bend given to these arms, besides having an
ornamental effect, is very useful, in order to prevent any part from interfering with the
other parts which are behind, by elevating them entirely above them. The extremities
n 971
<nnr>ii i!
ff ffll1Filffll^l?ffl!af»]tifTT
u
rr
l^lli|'^^;'^i^l^J'll!p«f^^l'f'^^i^^HpT^T^
of these arms at the termina-
tion of the bends behind, are
connected by a cross bar, which
has also a circular bend in the
middle,projecting downwards for
a reason similar to that already
assigned. This bend is con-
cealed inyi^. 965, bat visible in
the front elevation, fig. 971.
From the middle of the bend,
the presser is connected with
the middle treadle by a depend-
ing wire appearing at y^fig* 965,
and thus, by the pressure of that
treadle, the presser isforced down
to close the barbs of the needle.
The re-ascent of the presser is
sometimes effected by means of
a counterpoising weight passing
over a pulley behind ; and some-
times by the reaction of a wooden
spring, formed of a strong hoop
like tibiat represented at k. The
latter of these is preferred, espe-
cially by the Nottingham hosiers,
because, as they assert, it makes
the presser springnp with greater
rapidity, and consequently saves
time in working. How fiir this
may be practiodly the case, it
would be superfluous here to
investigate; but it is obvious
that the wooden spring, if very stiff, must add much to the hosier's exertion of his foot,
already exercised against the united spring of all his barbs ; and this inconvenience is
H H 4
i i @
J S 3
JB
472 HOSIERY.
iDuch compltuaed of b; those vho have been Bceastomed to work irith tlK eoantei^
At I. ire two palUjs or wheeli, of differcDt dfaimetert, moring upon ■ connnoii cratre,
bj which the jack ginkers are relieTed from the back spriags, and thrown downwaidl
to form the loop« npon the needlel. Abonl the larger wheel ii a band of whipeord,
pauing twice roncd, Ihe extremitie* of which are attached to what is called the slur,
which diiengages Ihe jacks from the back springs. The smaller pulley, by anoiher
band.eomminiicstea with tberight and left treadle; so that these treadles, when pressed
allemstely, torn the pulleys aboot in an inierled order. The directions of these
bands also appear more plainlj in the front eleTstion, Jig. 971. The eoDBtruction of
the alor, and its effect apon the jacks, will also be reodered appareol by ^. 970. In
this figure, eight jacks are represeoled in sectioo, the tail part of three of which, ), i,
3, are thrown up by the slur in it* progress from left to right ; the fonrth is in the
act of rising, and the remoioing four, G, G, 7, and t<,aTe still unacted apon, theslarnot
yet having reached ihera. As the slur acts in the direction of the dolled line x.x._fif.
SG8, behind the centres of the jacks, it is hardly necesasry to remark, that this forcing
up of the tails must of conrse depress the joints by which the sinkers in front are sus-
pended ; the jack sinkers fUling snccessirely from the loops on every alteroale
needle, in the way represented at
-^ ^ fig. 973. where both kinds of
sinkers appear in section, the light
g^j part expressing what is kbore the
'' point at which the throat c^ the
sinker operates npon the thread,
and the dark psrt what is below.
The second set, or. as they are
called, the lead sinken, from the
manner of joining them, and sospending Ihem from the bar above, appeir still elevated;
the position of the bar being represented by the line A, n. But when these are pnlird
down to the level of ihe former hy the operator's hands, the whole looping will be
comiileted. snd the thread c, n, which la still slack, will be bmnght to its full and
proper degree of tension, which is regnluted by slop screws, so SE to be tempered or
altered at pleasure. The sinking of this second set of sinkers may be easily ex-
plained by^j; 974, Tbedireclioo
of [he sinkers is expressed by ihe
line E ; the bar from which they
are sospended will be at a ; the top
frame is in the direction from a to
n ; the back slondsnls st d, and the
joint at B. is Ibe centre of motioo.
If E is palled perpendicularly down-
wards, the spring c will be con-
tracted, and its upper extreme point,
a. will be broaght nearer to its lower extreme point f, which is fixed. Again, when
the force which has depressed e is removed, the spring c will revert to its former stale,
and the sinkers will rise. The raiting of the jack sinkers and jscki takes place at Ihe
same lime, by the hosier raising his hands ; and for the cause of this we must revert
to fig. 9GB. The lead sinkers in rising lay hold of notches, which raise the extreme
parts of the set of jacks z, z, which ne called hslf-jocks. Between the extremities ot
these at z z, Is a cross bar, which, in descending, presses sll Ihe intermediaie jacks
behind the common centre, and restores them to their original posture, where they
are secured by the back springs, until they are again relieved by the operation of ibe
slur recrossing at the next course.
WorkiHgqfUu/raat. — In order to work a frame, the whole apporatnt being pre-
viously pot into complete order, the hosier places himself on the seat n in front, and
provides himself with a bobbin of yarn or stuff. This bobbin he places loosely on a
vertical pin of wire, driven into one side of the frame contiguous to the needles, so
that it may tnm freely as the stuff is unwound from it. Taking the thread in his
hand, he draws it loosely along the needles, behind the barbs, and under the throats
of the sinkers. He then presses down one of the Ireadles to pass tbe slur along, and
unlock the jacks (roro the back springs, that they may tail in succesaioa. When Ibis
is done, the number of loops thus formed is doubled hy bringing down the lead ainken,
end the new formed loops are lodged nudet Ihe barbs of the needles br bringing
forward Ihe sinkers, llie preceding coarse, snd former fabric, being then sgsin
pushed back, tbe barbs ate shut by depressing the middle treadle, and forcing down
the prcsser npon the needles. The former vrork is now easily brought over the shut
needles, after which, by raising the hands, both sels of sinkers are raised ; the jacks
are locked by the back springs, and Ihe hosier goes on to another course.
HOSIERY.
473
From this it will \>e apparent, that the remark made in the outset is well founded,
that there are in reality no complicated or difficult moyements in the stocking-frame.
Almost the whole are merely those of lerers moying upon their respective falcra, ex-
cepting that of the carriage which gives the horizontal motion to the sinkers, and that
is merely an alternate motion on fonr wheels. Yet the frame is a machine which re-
quires considerable experience and care, both to work it to advantage, and also to keep
it in good order. This circumstance arises greatly from the small compass in which
a number of moving parts must be included. Owing to this, the needles, unless
cautiously and delicately handled, are easily bent or injured. The same circumstance
applies with equal or greater force to the sinkers, which must be so very thin as to be
easily ixgured. But as these must work freely, both in a perpendicular and horizontal
direction between the needles, in a very confined and limited space, the slightest varia-
tion in either, f^om being truly and squarely placed, unavoidably injures the others.
YThen a hosier, either ignorant of the mechanical laws of their relation to each other,
or too impatient to wait for the assistance of another, attempts to rectify defects, he in
most cases increases them tenfold, and renders the machine incapable of working at
all, until repaired by some more experienced person. This circumstance has given
rise to a set of men employed in this trade, and distinguished by the name of upsetters ;
and these people, besides setting new frames to work, have frequently more employ-
ment in repairing old ones injured by want of care or skill, than many country
apothecaries, who live in unhealthy parishes, find in tampering with the disorders of
mankind.
It seems unnecessary to go further into detail respecting a machine so well known,
and which requires practical attention even more than most others. It may, there-
fore, be sufficient to describe shortly some of its varieties, the most simple and common
of which is the rib stocking-fhkme«
Bib stocking-frame. — This frame, which, next to the common frame, is most ex-
tensively in use, is employed for working those striped or ribbed stockings, which are
▼ery common in all the different materials of which hosiery is formed. In principle
it does not differ from the common frame, and not greatly in construction. The pre-
ceding general description will nearly apply to this machine with equal propriety as
to the former ; that part, however, by which the ribs or stripes are formed, is
entirely an addition, and to the application of this additional machinery it may be
proper to pay the chief attention, referring chiefly to Jig. 971, which is a front
elevation. This figure has been already referred to for the illustration of those
parts of the machinery which are common to both, and those parts therefore require
no recapitulation. The principle of weaving ribbed hosiery has considerable
affinity to that of weaving that kind of cloth wMch is distinguished by the name of
tweeling, for the formation of stripes, with some variation arising merely from the
different nature of the fabric. In cloth weaving, two different kinds of yam inter-
secting each other at right angles, are employed $ in hosiery only one is used. In
the tweeling of cloth, striped as dimity, in the cotton or kerseymere, and in the woollen
manufacture, the stripes are produced by reversing these yams. In hosiery, where
only one kind of yam is used, a similar effect is produced by reversing the loops.
To effect this reversing of the loops, a second set of needles is placed upon a vertical
Arame, so that the bends of the hooks may be nearly under those of the common
needles These needles are cast into tin moulds, pretty similar to the
former, but more oblique or bevelled towards the point, so as to pre-
vent obstructions in working them. They are also screwed to a bar
of iron, generally lighter than the other, and secured by means of plates:
this bar is not fixed, but has a pivot in each end, by means of which
the bar may have a kind of oscillatory motion on these pivots. Two
Arames of iron support this bar ; that in which it oscillates being nearly
vertical, but inclined a little towards the other needles. Fig, 975,
which is a profile elevation, will serve to illustrate the relative position
of each bar to the other. The lower or horizontal frame, the ends only
of which can be seen in fig. 97 1, under a a, appears in profile in^^. 975.
where it is distinguished by d. The vertical frame at a is attached to
this by two centre screws, which serve as joints for it to move in. On
the top of this frame is the rib-needle bar at /) in Jigs. 965 and 975,
and one needle is represented in Jig. 975 at /I At ^ is a small presser,
to shut the barbs of the rib -needles, in the same manner as the large
one does those of the frame. At h is one of the frame needles, to show
the relative position of the one set to the other. The whole of the rib-
bar is not fitted with needles like the other ; for here needles are only
placed where ribs or stripes are to be formed, the intervals being filled
up with blank leads, that is to say, with sockets of the same shape as the others, but
474 HOT FLUE.
vlthout oeedlM i being merely dengoed to fill the bar uid preserre tW ii
Two mull bandlM depend fVom the oeedle bar, by which the oieUUtoty motion npon
the upper ceatrn i> given. The rising and unking motion ii eommuiiated. to tbii
macbme b; chwns which ftre Utacbed to iron iliderv below, and which are wmovfai
b; the hoaier's heel when neceuary. The prcwnre takes place parllj bjr the acaoa
ot the iinall presaer, and parllir by the motion of the needJea in deaoending. A nsaU
iron slider i> placed behind the tib-needlea, which riaea ai they deacend, aod aerrcalD
free the loop* fierfectly from each other.
la the weaving of rihbed hoaiery, the plain and ribbed cnanca are wrought aher>
nately. When the plain are finiahed. the rib-needlea are raiaed between the odicr^
bat no additional stiifT ii aapplied. The rib-needlea interaectiiig the plain onea, merelj
lay hold of the laat thread, and by again brinnng it ihrongh that which waa on Sm
rib-needle before, give it an additional looping, which r«Teraea the line of chain-
ing, and raiaea the rib abore the plain intcrralt, which have only rewired a Dngle
FLUE 'u the name given in England to an apartment heated by Kotm or
[npea, in which padded and ptinied ealicoea are dried hard. Fif. 976 rcprc*
knitting.
eoT-
senta the itmpleit fbnn of inch a fine, beated by the T«rtie«l round iron stove c, tnm
whoae top a wide iqnare pipe proceeds upwards in a ali^tly inclined direction, which
reoeiTca the corrent of air heated by the body and capital of the store. Id this wide
HOT FLUE. 475
ehamiel Atn ut poltej*, iriA cords or bandi which (nipead b^ liooki ud coDdact
the web of olico fyom the entrance U a, where the operMive aiti, to near (he point
A, and back (gain. This circuit may be repeated once or oftener till the plods are
perfectlj dried. At D the driviue piitlej connected with the main ihaft i« ahown.
Near the feet of (be operatire is the canjron or reel apon which the main goodi are
roUed in an endless web ; so thai their circulalion in tbe bat-air ohaunel can be con-
tinaed without interrupli<Hi, ai Inog as may be neceasarj.
Fig. 977 is a cross section of the apparalui of ths rtgubr bot-flne, as it is moanted
in (he moat scientific calioo works of
Eo^and, those or James Thomson, Esq.,
of Primroee, near Cliiheroe, I^ncuhire.
a a D u is an arched Apartment, nearl; 30
yards long, b; 13 feet high, lod 10 feel
wide. ThroDfth ahoDl one half of this
gallery there is a boriiontai floor sup-
ported □□ arches, above which is the driest
space, through which the goods are finally
passed befiDre they escape from the hot-
flue, after they hare been previously ex-
posed to the hot but somewhat moist sir
of the lower compartmAt. A large
square fine covered with casl-iroD plates
runs aloDff the whole bottom of the gal-
lery. It la diTided into two long parallel
laolls, whose sections are seen at u, u,Jig.
977, covered with the cast-iron pUtesuo, ^
grooved at their ends into one another.
The thickness of these plates is increased
progtvsaifely as they come nearer to the
fireplace w tiimace. There are dampen whici
the heat of the stove, h A are the air-passogei
and which by means of a long iron rod, mounted with iron plates, may be opened oi
closed together to any degree. A A are the cast-iron supports of the tinned brats rolten
which guide the goods along, and which are fixed to the cross piece* represented by
T T,fig. 977. /JareironbaTifor tapporting the veDtilators or Eus (see Fodndbt and
VcNTn^TioK). These &ns are here enclosed within a wire grating. They make
aboQl 300 turns per minute, and expel the moist air with perfect effect, s indicates ths
[loaitian of tbe wiikdows, which extend thronghonl the length of the bnilding. ( is a
gM-li^t jet, plae«d at the side of each window to tapply illumination fbr night work.
The piece is stt«lobed along the whole extent of the gallery, and runs throogh it in
tbe coune of one minate and a half; beiog exposed during its passage to the beat of
21!° Fahr.
Id Jig. S7S, A is the iron door of eatnooe to the bot-floe gallery t it ( i* the pad-
ding marchine, where the j,^g
gofids are imbued with
the general mordnnt The
apeed of this machine
may be varied by means
of the two conical drums
c c, which drive it ) since,
when the band c c i«
brought by its (brks, and
adjusting screws, nearer
to tbe narrow end of the
lower dram, tbe cylin-
der upon tbe sanie shaft I
with tbe latter is driven
quicker; and tict ttrta.
Over s i> the corda are I
shown ftar drawing tbe
dram mechaaism Into gear with the main shaA band, r, T, x ; or for throwing it ontof
gear. The palleys r I carry the bands which transmit the motion to the padding
machine. A cylindrical drum exterior to the hot-fine, covered with Sannel, serve* to
worive the end of the series of pieces, and to draw them through the apartment.
This mode of drying the padded calicoes requires for each piece of SS yard* _thre«
pounds of coals for the fhmace when a &n is employed, and fi>ar poimd* witboot
It. See Calico PaumNa.
476 HYDRAULIC CRANES.
HUNGARY WATER. Supposed to be named after a qneen of Hnngaiy, who
used it as a eosmetic : it is prepared bj distilling rosemary. See Ead de OoijoavK,
HYACINTH. The name under which are included the transparent, brij^fat-
coloured varieties of zircon. Hyacinth differs from jargoon merely in colour, whieh
is orange-red passing into poppy-red. Though not much worn at the present time it
is a valuable gem, and makes a very superb ring-stone when of a bright tint and free
from flaws. The larger pieces are sometimes made into seals. Hyacinths occur in
the sand and alluvial deposits of certain rivers in Ceylon, also in the state of sand,
mingled with various other substances, in the bed of a stream at Ezpailly (Haute Loire)
in France, as well as in basalt near the same place. It is also found in volcanic tuff
in Auvergne,in Bohemia, Saxony, the Tyrol, Transylvania, Greenland, in the zireoa-
syenite of Fredericks -viirn in Norway, and in the iron mines of Arendal ; also at
Miask in the Urals, Vesuvius, at Santa Rosa in New Grenada, at Scalpay in Harris,
Scotland, Egypt, the East Indies and elsewhere. The hyacinth-red varieties of ziroon
are sold by the inhabitants of Ceylon as inferior rubies. — IL W. B.
HYDRATES are compounds of the oxides, salts, &c., with water in definite or
equivalent proportions. Thus slaked lime consists of one atom of quick-lime » 2S,
+ one atom of water « 9, of which the sum is 37 on the hydrogen scale. ** The very
different functions performed by water in the various modes of combination it affects
render it nec-essary to adopt a definite principle of nomenclature in this respect. . . .
I shall employ the word hydrate only where the water is ^mbined with a base, such
as a metalUc oxide, thus, hydrate of lime, hydrate of potash, hydrated oxide of lead."
— Kane.
HYDRAULIC CEMENTS. See Mobtab.
HYDRAULIC CRANES. The application of water-pressure to cranes is due to
Sir Wm. Armstrong. These are now so generally applied, that although the subject
belongs properly to engineering, it is thought advisable to include some notice of these
valuable and interesting machines in this work. A statement made, by the request
of the British Association in 1854, by the inventor himself, so completely explains all
the peculiarities of these cranes, that the paper is reproduced firom the proceedings of
the Association.
** The employment of water- pressure as a mechanical ag^nt having recently under-
gone a great and rapid development, I may be permitted to make a few obe^ations
on the successive steps by which its present importance has been attained. In so
doing I shall commence with the year 1846, in which, after many preliminary ex-
periments, I succeeded in establishing, upon the public quay at Newcastle-upon-
Tyne, the hydraulic crane which has formed the basis of what has since been effected.
" This crane both lifted the weight and swung round in either direction by the
pressure of water, and was characterised, like all other hydraulic cranes since made,
by remarkable precision and softness of movement, combined with great rapidity of
action.
'* The experiment thus made at Newcastle having proved satisfactory, I soon after-
wards obtained authority, through the intervention of Mr. Hartley, the Dock Sur-
veyor of Liverpool, to construct several cranes and hoists upon the same principle at
the Albert Dock in that town, where they were accordingly erected, and have ever
since continued in operation.
" The next place at which these cranes were adopted was Grimsby New Dock, wbeie
an important step in the advancement of this kind of machinery was made on the
suggestion of Mr. Rendel, who pointed out its applicability to the opening and closing
of dock gates and sluices, and instructed me to extend its application to those objects.
An extensive system of water-pressure machinery was accordingly carried out at
that dock, and the result afforded the first practical demonstration that the pressure
of a column of water could be advantageously applied as a substitute for manual
labour, not merely for the cranage of goods, but also to give safe and rapid effect to
those mechanical operations which are necessary for passing ships through the
entrances of docks.
*' In all these instances the moving column of water was about 200 feet in elevation.
At Newcastle and Liverpool the supply was derived from the pipes communicating
with the town reservoirs, but at Grimsby a tower was built for supporting^ tank into
which water was pumped by a steam-engine. In the former cases, the fluctuation of
pressure, consequent upon the variable draught from the pipes for the ordinary
purposes of consumption, proved a serious disadvantage ; but this objection had no
existence at Grimsby, where the tank upon the tower furnished a separate source of
power, undisturbed by any interfering conditions. Nothing could be more effectual
for its purpose than this tower ; but, in the natural course of improvement, I was
subsequently led to the adoption of another form of artificial head, which possessed
the advantage of being applicable, at a comparatively small cost, in all situations, and
HYDRAULIC CRANES.
477
979
of lessening the sixe of the pipes and hydraulic machinery, by affording a pressure of
greatly increased intensity.
** The apparatus thas substituted for a water tower I named *' the Accumulator^** fVom
the circumstance of its accumulating the power exerted by the engine in charging it
The accumulator is, in fact, a reservoir giving pressure by had instead of by elevation,
and its usci like that of every provision of this kind, is to equalise the strain upon
the engine in cases where the quantity of power to be supplied is subject to great and
sudden fluctuations.
** The construction of the accumulator is exhibited in Jig. 979, and needs but
little explanation, a, cylinder, b,
plunger ; c c, loaded weight case ;
D, n, guides for ditto ; s, pipe Arom
pumping engine ; f, pipe to hydrau-
lic machine. It consists of a large
east-iron cylinder, fitted with a plun-
ger, from which a loaded weight case
is suspended, to give pressure to the
water injected by the engine. The
load upon the plunger is usually such
as to produce a pressure in the cy-
linder equal to a column of 1500 feet
in elevation, and the apparatus is
made sufficiently capacious to contain
the largest quantity of water which
can be drawn from it at once by the
simultaneous action of all the hy-
draulic machines with which it is
connected. Whenever the engine
pumps more water into the accumu-
lator than passes direct to the hy-
draulic machines, the loaded plunger
rises and makes room in the cylinder
for the surplus; but when, on the
other hand, the supply from the en-
gine is less, for the moment, than the
quantity required, the plunger, with
its load, descends and makes up the
deficiency out of store.
"The accumulator also serves as
a regulator to the engine ; for when
the loaded plunger rises to a certain
height, it begins to close a throttle*
Talve in the steam- pipe, so as gra-
dually to reduce the speed of the en- ^^!
gine until the descent of the plunger
again calls for an increased produc-
tion of power.
** The introduction of the accumulator, which took place in the year 1851, gave
a great impulse to the extension of water-pressure machinery, which is now either
already applied, or in course of being applied, to the purpose of cranage throughout
all the great dock establishments in London, as also to a considerable extent in
Liverpool and other places. I have also applied it extensively to railway purposes,
chiefly under the direction of Mr. Brunei, who has found a multitude of cases,
involvmg lifting or tractive power, in which it may be made available. Most of
these applications are well exemplified at the new station of the Great Western
Bail way Company in London, where the loading and unloading of trucks, the
hoisting into warehouses, the lifting of loaded trucks from one level to another, the
moving of turn-tables, and the hauling of trucks and traversing machines are all
performed, or about to be so, by means of hydraulic pressure supplied by one central
steam-engine with connected accnmulatorsw Mr. Rendel also, after having successfully
adopted Uie low-pressure system to the working of the gates and shuttles at Grimsby,
has since applied the high-pressore, or accumulator system, to the same purposes at
other new docks, and a similar adaptation is being made by other eminent engineers
at most of the new docks now in course of construction.
'* I have also adapted hydraulic machinery to the opening and closing of swings
bridges and draw-bridges of large dimensions ; and, in &ct, there is scarcely any
mechanical operation to which human labour has been hitherto applied as a mere
478
HYDRAULIC CRANES.
moving power, which may not be efficiently perfbnned by means of water-pRMOR
emanating from a steam-engine and accumolator. Even if band-laboor be retaioed
as the source of the power, the intervention of an accamulator will in many casa
both economise laboor and increase despatch. For example, a pair of heavy dock-
gates requires the constant attendance of a considerable number of men, whose Isboor
is only called into action occasionally, viz. when the gates are being opened or doted.
Now, if an accumulator, charged by hand-pumps, were used, the labour empiojed
would be constant, instead of occasional, and the power collected in the aceamalitor
by the continuous process of pumping would be given out in a concentrated form, and
thus the ultimate result would be effected with f«wer hands and greater despatch tbn
where manual labour is directly applied.
" The form of pumping-engine which I generally use for charging the accnma-
lator is represented in fig, 980. It consists of a horizontal steam-cylinder, with tvo
980
force-pumps connected directly with the piston. These foree-pomps are snpplici
with water from a cistern over the engine-room, into which the water dischaifed by
the cranes is generally brought back by a return-pipe, so that the water is not wasted,
but remuns continuously in use. , . .
" With a pressure representing a column of 1 500 feet, the loss of head by ftictwo m
the pipes forms so small a deduction from the entire column as to be a matter of no
consideration, and consequently the distance at which the engine may be sitoated
from the points where the hydraulic machines may be placed is of little importance,
except as regards the cost of the pipe. It is advisable, however, if the pipe be vej
long, to apply an accumulator at each extremity, so as to charge the pipe fr®""* "**
ends.
** With regard to the mechanism of hydraulic cranes, the arrangement which 1 ^^
adopted, and have ever since adhered to, consists of one or more hydranlic presws,
with a set of sheaves, used in the inverted order of blocks and pulleys, for the porpow
of obtaining an extended motion in the chain from a comparatively short ^^^r^
the piston. This construction, which characterises nearly all the varieties w the
hoisting and hauling machines to which I have applied hydraulic pressure \&J^'
hibited vafig, 981, which represents one of these presses with sheaves attached, to
multiply the motion fourfold. In cases where the resistance to be overcome ▼a"^
very considerably, I generally employ three such cylinders, with rams or P^^
actmg either separately or conjointly upon the same set of multiplying »n«*^
according to the amount of power required. -
•; In hydraulic cranes the power is applied, not only for lifting the load, but also «>r
swmging the jib, which latter object is effected by means of a rack orchain opertnjB
on the base of the movable part of the crane, and connected either with a cyhader
and piston havmg alternate motion, like that of a steam-engine, or with twop«««
appl ed to produce the same effect by alternate action. -^
^ The absence of any sensible elasticity in water renders the motions resulting fro«
J
HYDRAULIC CRANES.
other. Under meh circouutaDcts, if the water-paaaage* be soddenl; clowd by ihe
regnlating valTe, it is obvioai tbat Ihe piston, impelled fomard by Ihe momeDtum of
the loaded jib, bat met b; an uajUlding body of water deprived of onllet, tronld be
broaghl to real lo abraplly. u to caose. in all probability, the breakage of tbe machine^
So alao, ia lowering a heaTy weight with considerable Telocity, if the eMapepawage
be too BoddeDly closed, a limilar risk of injury voold arise Ihiiii the abrupt ctoppage
of the wdght, if a remedy were not proiided; but these liabilities are effectuaUy
remoied by applying, in coDneclion vtih the water-passages to the cylinder, a small
ctBCk'valre, opening upwards against the pressure into the anpply-pipe, ao as to
permit the pent-up water in the cylinder to be pressed back into the pipe whenerer it
becomes exposed to a compressive force exceeding the pressure oa Ilia accumulalor.
By this means all jerks and concngsiaoi are avoided, and a perfect control over the
movement of the machine is combined with great sottness of action.
" With regard lo tbe kind of valves used for water-pressure machines, I find that
either tift-valveB or slide-valves may be effectually applied, and kept tight under
heavy pressures, provided that sand be eiclnded from the water, and the valves be
nude of proper materiaL
" In catea where a mare prolonged movement is required tban multiplying sheave*
will conveniently afford, I employ rotative machines of various constmccions. Far
he avj -pressures, such as an accumulator affords, as arrangement consisting of three
plungers, conneclcd with a triple crank, and bearing a general resemblaDoe to a three-
throw plunger pump, is well adapted for the parpo«e- The admission and exhaust
valves are mitred spindles, pressed down by weights and levers, and lifted in proper
rotation by cams fixed for that purpose upon a separate shaft ; and these valves are
associated with relief-clacks, to obviate the concussion which would otherwise b« liable
to lake place at the turn of each stroke-
" Tbe liability of water-pressure machinery to be deranged by troal has oflen been
adduced aa an objection lo its use ; and upon this point I may observe — first, that I
have never experienced any interference from this cause when the macbinea we^
placed, as they generally are, beneath tbe surface of the ground, or wilhina building;
and secondly, tbat when they are unavoidably exposed, all risk may be prevented by
letting oat tbe water in tiottj weather whenever the machines cease working.
" When the moving power consists of a nalural column of water, the pressure rarely
exceeds S5D or 3D0 feet, and in lucb casea I have employed for rotative action a pair
of cylinderaand pistona, with slide- valves, resembling in some degree those of a high-
pressore engine, but having relief- valves, to prevent shock at the turn of tbe stroke.
J-'ig. 98S shows a sUde-vidve adapted for the turning apparatus of a crane, but
the relief-chtckg of which are equally applicable to a water-pressure engine of the
coostmction in question. Two of these clacks open aguiuBt the pressure in tbe supply-
pipe, so aa to afford an escape for tbe water, which would otherwise be abut op in the
cylinder when the exhauat port closes, and tbe other two oommuDlcale with tbe
discharge -pipe, so as to draw in a portion of waste water lo fill up tbe small vacaocy
which would otherwise be left in the cylinder on tbe dosing of the admiiaion port.
A, snpply pipe ; a, exhaust pipe ; c c, pipes to cylinder ( d ii, clacks opening agiunst
480 HYDRIODIC ACID.
preuure ; B B, cUcki opening from fxhaost About foor jean ago I ci
four hjdraalre eDgioea upon this principle at Mr. Beaamout'i lead mioea id Nonhma-
berland, at the inslaiice of Mr. Sopwitb, Mr. Ban-
centlj been added at the um« place. They are
uaed fbr crnsbing ore, for baL&ting materials fttHa
the mines, for pumping -iraler, and for dri-ritig a
circular lair and other nuchlnery. See Wati:^-
PBBBtDKE Hacbineht, implied lo mi*e*.
" If in prc^nas of time railways slioald be gt-
uerallj extended into mountaioous districu, so at
10 render them aeeeMible for mannfacUiring pnr-
pasrs, the rapid streams vfaichabonDd iaaacb local-
ilieawill probably become valuable sources of motiTe
power, and a wider Geld ma; then be afforded forlbe
application of nater-presiurt engines to natural Uta.
" The object, bowever, which I have chiefl; bal
in lie* tioce I first gate attention to this scigto.
has been to provide, in substitution of m&Doal la-
bonr. a method of working a multiplicity of ma-
chinen, intermitlent in their action, and extmding
OTer a large area, by means of transmitted power
produced bj a sleam-eogine and accamulated at
one central point. The common mode of commn-
nicating power by shafting could only be applied in cases vhere the machine* were
collected within a small compass, and vbere the accomulatioD of power neccMSfy
to meet Tarying resistance did not exceed that which a fly-wheel would aSbnL
Compressed or exhausted air was almost equally inapplicable lo the purpose* I cm-
teraplated, in consequence of the many objections which its elasticity involrrs, n
well as the liability to leakage, which, in on extended system of pipes and machues,
requiring a malt it ode of joints, vslrts, and filling sarfhces, would form an insnnnoaBI-
able difflcnily. Bat Che use of water as a medium of transmission is free from all
these objections, and its fitness for the purpose intended is DOW thoroughly establitbcd
by the results which have been obtained."
HYDRADHC MACHINERY for mines. See WiTEB and yf ^Tn-rmeaeca
Enoweb. Tubhine.
HYDRAULIC PRESS. See Wateb PREsanait Machinbkt.
HYDIilODlC ACID iAride Hydriodique, Fr. ; Hsdriod^are, Germ.) is an acid
formed by Ihe combination of ) ! 7 parts of Iodine with I part of hydrogen by weighi,
and by measure equal Tolames of iodine vapour and hydrogen combined wilhoat cob-
densalion. It is obtained pure and in the gaseous state by introducing into a gtass lube,
closed at one end, a little iodine, then a small quantity of roughly-powdered glass
moistened with water, upon this a few small fragments of phosphorus, and lastly more
glass ; this order, iodine, glass, phospborus, glass, is repeated until the tube is two-thirdi
nlled. A cork and narrow bent tube ore then Sited and gentle heat applied, when ibe
bydriodic acid is liberated, end may be collected in dry bottles by ihe displacement of
air. Another process is to place in a small retort 10 parts of iodide of polassiom villi
fi of water, add 30 parts of iodine, then drop in cautiously 1 pan of pfaoaphoms col
into small pieces, and apply a gentle heat ; bydriodic acid will be formed abundanlly,
and m»y be collected as before stated. The following equation expresses thereadioa:
aKI + flI+ P + 8H0 yield BKCHCPC + THL
Hydriodic acid greatly resembles hydrochloric acid ; it is colourless, and hi|^lr acid,
it fumes in the air, aud is very soluble in water. Its density is 4'4, and under strong
pressure condenses to a yellowish liquid, which solidifies at G0° Fahr.
Uydriodic acid in solution is much more easily prepared, by suspending iodine in
water, and passing a stream of washed hydrosulphurie acid through it until thecolaor
disappears ; it is then heated to expel the hydrosulphuric acid, Ihen allowed to rest.
when it may be decanted fW>m the precipitate of sulphur. The reaction conaista
umply in the displacement of the sulphur by the iodine, HS-t-licHI + S.
This liquid may be evaporated until it acquires a density of 17, when it consists of
HI -f 11 HO. It then distils at 262° Fahr. vitiiout decomposition. The solntioo
cannot be long kept, it being decomposed by the oxygen of the air with the liberaiioa
of iodine, which imparts a dark colour to it. Chlorme decomposes it instaatty, with
liberation of the iodine.
The solution of bydriodic acid and of the iodides possess the power oTdissolTuig a
con«derable quantity of iodine, forming a dark soltttion. — H, K. B.
HYDROCHLORIC ACID 481
HTDROBROMIC ACID. HBr. See Brobeins.
HTDRO-CARBON. See Carburettsd Hydrooen
HYDROCHLORIC ACID. (Chlorhydriqui, Fr. ; Sahuaurt, Oerin.) A compound
of chlorine and hydrogen which is a coToarless gas of a peculiar suffocating, pungent
odour ; it reddens vegetable blues, but possesses no bleaching properties. The solution
of hydrochloric acid in water is the mubiatic acid and spirit of salt of commerce ;
anciently JUarine Acid, 2 volumes of chlorine and 2 volumes of hydrogen combine
to form 4 volumes of this acid. HCl ; eq. 86*5. It is best prepared by heating a
mixture of 6 parts of chloride of sodium Icammon salt) and 10 parts of concentrated
sniphuric acid, previously diluted with 4 parts of water, in a capacious glass retort, con-
nected with a set of Wooife*s bottles. This acid is extracted on a large scale from sea-
salt, by the action of sulphuric acid and a moderate heat ; but it was originally obtained
from the salt by exposing a mixture of it and of common clay to ignition in an earthen
retort. The acid gas which exhales is rapidly condensed by water. 100 cubic inches
of water are. capable of absorbing no less than 48,000 cubic inches of the acid gas,
whereby the liquid acquires a specific gravity of 1*2109 : and a yolume of 142 cubic
inches. This vast condensation is accompanied with a great production of heat ;
-whence it becomes necessary to apply artificial refrigeration, especially if so strong an
acid as the abore is to be prepared. In general, the muriatic acid of commerce has
a specific graTity varying firom 1*15 to 1*20, and contains, for the most part,
considerably less than 40 parts by weight of acid gas in the hundred. The above
stronger acid contains 42*68 per cent by weight; for since a cubic inch of water,
which weighs 252*5 grains, has absorbed 480 cubic inches »1 88 grains of gas ; and
352'5 + 1 88 » 440*5 ; then 440*5 ; 188 : : 100 : 42*68. In general a very good approxi-
mation may be found to the percentage of real muriatic acid, in any liquid sample, by
multiplying the decimal figures of the specific gravity by 200. Thus, for example, at
1*162 we shall have by this rule 0*162 x 200 => 32*4, for the quantity of gas in 100
parts of the liquid* Muriatic acid gas consists of chlorine and hydrogen combined,
-without condensation, in equal volumes. Its specific gravity is 1*247, air » 1*000.
By sealing up muriate of ammonia and sulphuric acid, apart, in a strong glass tube
rc'curved, and then causing them to act on each other, Sir H. Davy procured liquid
muriatic acid. He justly observes, that the generation of elastic substances in close
vessels, either with or without heat, offers much more powerful means of approximating
tiieir molecules than those dependent on the application of cold, whether natural or
artificial ; fbr as gases diminished only ,}g in volume for every degree of Fahrenheit's
scale, beginning at ordinary temperatures, a very slight condensation only can be
produced by the most powerful freezing mixtures, not half so much as would result
from the application of a strong flame to one part of a glass tube, the other part being
of ordinary temperature ; and when attempts are made to condense gases into liquids
by sudden mechanical compression, the heat instantly generated presents a formidable
obstacle to the success of the experiment ; whereas, m the compression resulting from
their slow generation in close vessels, if the process be conducted with common pre-
cautions, there is no source of difficulty or danger ; and it may be easily assisted by
artificial cold, in cases where gases approach near to that point of compression and
temperature at which they become vapours. — Phil Trans, 1823.
The muriatic acid of commerce has usually a yellowish tinge, but when chemically
pure it is colourless. It fumes strongly in the air, emitting a corrosive vapour of a
peculiar smelL The characteristic test of muriatic acid in the most dilute state, is
nitrate of silver, which causes a curdy precipitate of chloride of silver.
The preparation of this acid upon the great scale is frequently effected in this
country by acting upon sea-salt in hemispherical iron pots, or in cast-iron cylinders,
with concentrated sulphuric acid ; taking 6 parts of the salt to 5 of the acid. The
mouth of the pot may be covered with a slab of siliceous fireestone, perforated with
two holes of about two inches in diameter each, into the one of which the acid is
poured by a funnel in successive portions, and into the other, a bent glass, or stone-
ware tube, is fixed, for conducting the disengaged muriatic gas into a series of large
globes of bottle glass, one-third filled with water, and laid on a sloping sand-bed. A
week is commonly employed for working off each pot ; no heat being applied to it till
the second day.
The decomposition of sea-salt by sulphuric acid was at one time carried on by
some French manufacturers in large leaden pans, 10 feet long, 5 feet broad, and a foot
deep, covered with sheets of leads, and luted. The disengaged acid gas was made to
circulate in a conduit of glazed bricks, nearly 650 yards long, where it was condensed
by a sheet of water exceedingly thin, which fiowed slowly in the opposite direction of
the gas down a slope of 1 in 200. At the end of this canal nearest the apparatus, the
muriatic acid was as strong as possible, and pretty pure ; but towards the other end,
the water vras hardly acidulous. The condensing part of thi» apparatus was therefore
Vol. IL II
482 HVDEOCHLOEIO ACID.
tolerably complete ; but u the decompoiilioa of Ibe nit coald not be finiilied in tbe
leaden pins, the acid mixtiire had lo be drawn ont of them, in order to be eompletelj
decompoaed in a rererberatorf furnace ; ia tbii iray nearly 50 per cent, of (fae
muriatic acid wu loit. And besides, the great qiunticy of gu given off during' the
emptying of Che lead-chamben viu apt to luffocite the workmen, or (criouly injaiied
thpir luDgi, cauaiag scTcre bemoptyais. ' The employment of muriatic acid ia h>
inconsiderable, and tbe loa* of it incarred in the preceding procew ii of so little
coDKeqnence, that BDbiequently, both in France and in England, mlpbale of lods. for
the toda manufactare, haa been procured with the disupatian of the muriatic acid in
the air. In the method more lately retorted to. the gaieoui products are diaclwr^ed
into CKtensive vaults, where currents of water condense them and carry them off into
the river. The Eurrounding regelation is thereby saved in some meainiw from being
homed up, an accident whicb was previously snre to happen when fog* precipitated
the flailing gases upon the ^ound. At Newcastle, Liverpool, and MwteiUes, irbre
the coQsumpiion of murisiic acid bears no proportion to the nunn&ctnre of aoda,
this process is now practised npon a vast scale.
The apparatus for condenBing muriatic acid gas has been modified and changed, ol
lale years, in many difierent ways.
Tht Baitringue opparalat. At the end of a rererberalorj fumae«, TCctan^ar lead
trough or pan, abont I foot deep, of a width equal to that of the interior of the fbrnace,
thai is, about 5 feet wide, and 6} feet long, is encased id masonry, having ita apper
edges covered with cast-iron plates or fire tiles, and placed npon a level with the
passage of the flame, as it escapes ftota the rererberatory. The arch which coveta
^at pan forms a eonlinnatkin of the roof of the rererberatory, and is of the aame
height The flame which proceeds from the furnace eontajning the mixture of nil
and sulphuric acid is made to escape between the vault and the surface of the iroo
plates or fire tiles, through a passage only 4 inches in height. When the bamed air
and vapours reach (he extremity of the pan, they are reflected downwarda, and
made to return beneath the bollom of the pan, in a flue, which is aTterwards dirided
su as to lead the smoke into two lateral flues, which terminate in the chimney. The
pan is thus surroanded as it were with the heal and flame discharged tnaa the
reverberatory furnace. A door is opened near the end of the pan, fen- introducing
the charge of sea-salt, amounting to 1 3 bags of 2 cwt. each, or S-l cwL This door is
then luted on as tightly as possible, and for every 100 parts of salt, 110 of SDlpharic
acid are poured in, of specific gravity 1'594, containing 57 per cent, of dry acid.
This acid is introdnced through a fkiunel inserted in the roof of the furnace. Decom-
pi«ition ensues, muriatic acid gas mingled with steam is disengaged, and is eondncied
tlirough 4 stone- ware lubes into the refrigerators, where it isfinally condensed. T^ae
refrigerators consist of large stone- ware carboys, called rfone-jnuus in France, lo the
number of 7 Or S for each pipe, and arranged so that the neck of the one eomniDni-
cates with the body of the other ; thus the gas must iravene the whole seriea, and gets
in a good measure condensed by the water in them, before reaching the last.
When the operation is finished, the door opposite the pan is opened, and the
residuum in it is discharged, in the form of a fluid magma, upon a sqnare bed ot
bricks, exterior to the flimace. This paste speedily concretes on cooling, and is tboi
broken into fra^ents and carried to the soda manufaclory. The immense qoantity
4tf gas exhaled in discharging the pan, readen this part of the opeTMion vary painin]
HYDROCHLORIC ACID.
483
impossibility of completing the decomposition of the salt, since tbe residaom must be
run off in a liqaid state, finaJly, the damage sustained by the melting and corrosion of
the lead, &c, are among the causes why no more than 80 or 90 parts of muriatic acid
at 1*170 are collected, equivalent to 25 per cent of real acid for every 100 of salt em-
ployed, instead of much more than double that quantity, which it may be made to
yield by a well conducted chemical process.
The cylinder apparatus is now much esteemed by many manofactnrers. Fig, 983
represents, in transverse section, a bench of iron cylinder retorts, as built up in a proper
furnace for producing muri-
atic acid ; ajiijig. 984 a longi- 984
tudinal section of one retort
with one of its carboys of con-
densation, a is the grate ; 6, WW^
a fireplace, in which two iron
cylinders, c c, are set along-
side of each oUier. They are
5} feet long, 20 inches in dia-
meter, about \ of an inch
thick, and take 1-6 cwt of
salt for a charge ; d is the ash-
pit; e e are cast-iron lids for
closing both ends of the cylin-
ders ;yis a tube in the pos^
terior lid, for pouring in the
sulphuric acid; g is another
tube, in the anterior lid, for
the insertion of the bent pipe
of hard glazed stoneware h \
t is a three-necked stone-ware carboy ; A is a tube of safety ; ly a tube of communi-
cation with the second carboy \ mmmm are the flues leading to the chimney n.
After the salt has been introduced, and the fire kindled, 83:^ per cent of its weight
of sulphuric acid, of sp. gr. 1*80, should be slowly poured into the cylinder through
a lead funnel, with a siphon-formed pipe. The three-necked carboys may be either
placed in a series for each retort, like a range of Woulfe's bottles, or all the carboys of
the fh>nt range may be placed in communication with one another, while the last car-
boy at one end is joined to the first of the second range ; and thus in succession. They
must be half filled with cold water ; and when convenient, those of the front row at
least, should be plunged in an oblong trough of running water. The acid which con-
denses in the carboys of that row is apt to be somewhat contaminated with sulphuric
acid, muriate of iron, or even sulphate of soda ; but that in the second and third will be
found to be pure. In this way 100 parts of sea-salt will yield 130 parts of muriatic
acid, of sp. gr. 1-19 ; while the sulphate of soda in the retort will afford firom 208
to 210 of that salt in crystals.
It is proper to heat all the parts of the cylinders equally, to insure the simultaneous
decomposition of the salt, and to protect it from the acid ; for the hotter the iron, and
tbe stronger the acid, the less erosion ensues.
Some manufiicturers, wiUi the view of saving fuel by the construction of their fur-
naces, oppose to the flame as many obstacles as tibey can, and make it perform numerous
circulations round the cyUnders ; but this system is bad, and does not even effect the
desired economy, because the passages, being narrow, impair the draft, and become
speedily choked up with the soot, which would be burned profitably in a fk*eer space ; the
decomposition also, being unequally performed, is less perfect, and the cylinders are
more injured. It is better to nutke the flame envelope at once the body of ihe cylinder;
after which it may circulate beneath the vault, in order to give out a portion of its
caloric before it escapes at the chimney.
The fire should be briskly kindled, but lowered as soon as the distillation com-
mences ; and then continued moderate till the evolution of {^ diminighes, when it
most be heated somewhat strongly to finish the decomposition. The iron door is now
removed, to extract the sulphate of soda, and to recommence another operation. This
sulphate ought to be white and uniform, exhibiting in its fracture no ondecomposed
sea-salt.
Liquid muriatic acid has a Tcry sour corrosiye taste, a pungent suffocating smell, and
acts Tery powerfully upon a vast number of mineral, vegetable, and animal substances.
It is much employed for making many metallic solutions ; and in combination with
nitric acid, it forms the aquaregia of the alchemists, so called from iu property of dia-
solTing gokl. See Soda Manufacturb.
ii2
484
HYDROCYANIC ACID.
Table of Hydrochloric Acid, by Dr, Ure,
Acid
of 18(>
In 100.
100
Specific
Chlo-
Muriatic
Add
oriso
fnlOO.
66
Specific
Chlo-
Muriatic
1 Add
,ori2o
inlOa
32
Specific
Chlo-
MoTlatk,
Gravity.
rloe.
Gu.
GraTity.
rlue.
Gat.
Gravity.
rlnc.
Gas.
1-2000
39675
40*777
1*1328
26-186
26913
1*0637
12-697
13049
99
1-1982
39-278
40-369
65
1-1308
25-789
26*505
31
1*0617
12-300
12-641
98
1-1964
38-882
39-961
64
11287
25 392
26-098
30
1*0597
11-903
12233
97
1*1946
38-485
39-554
63
1*1267
24-996
25-690
29
1*0577
11-506
11-825
96
1-1928
38 089
39-146
62
11247
24-599
25*282
28
1-0557
11-109
11 418
95
1-1910
37-692
38-738
61
1-1226
24-202
24-874
27
1*0537
10-712
IIOIO
94
1-1893
37-296
38*330
60
1*1206
23-805
24-466
26
1-0517
10*316
1O-602
93
11875
36*900
37*923
59
1*1185
23-408
24 058
25
1-0497
9-919
10-194
92
11857
36-503
37-516
58
11164
23*012
23*050
24
1*0477
9-522
9-786
91
1*1846
36-107
37-108
57
1*1143
22-615
23-242
23
1-0457
9125
9-379
90
1-1822
35-707
36 700
56
1*1123
22-218
22-834
22
1*0437
8*729
9-971
89
1-1802
35-310
36-292
55
1*1102
21-822
22-426
21
1-0417
8-332
8*663
88
1 1782
34913
35-884
54
1*1082
21-425
22019
20
10397
7-935
8- 155
8?
1-1762
34-517
35-476
53
11061
21-028
21-611
19
1*0377
7-588
7-747
86
11741
34*121
35*068
52
11041
20632
21*203
18
1*0357
7-141
7-340
85
11721
33*724
34*660
51
11020
20-235
20-796
17
1-0337
6-745
7-932
84
1-1701
33-328
34*252
50
I -1000
19-837
20-388
16
1*0318
6-348
6-524
83
1-1681
32-931
33-845
49
1-0980
19-440
19-980
15
1-0298
5-951
6-116
82
1-1661
32-535
J3*437
48
1*0960
19-044
19-572
14
1*0279
5-554
6*709
81
11641
32*136
33*029
47
1-0939
18-647
19-165
13
1*0259
5-158
5-301
80
M620
31*746
32-621
46
1*0919
18-250
18-757
12
1*0239
4*762
5-893
79
M599
31-343
32-213
45
1-0899
17-854
18-359
II
1-0220
4-365
4*486
78
1-1578
30-946
31-805
44
1-0879
17-457
17-941
10
1-0200
3*968
4 078
77
1-1557
30-550
31-398
43
1-0859
17-060
17-534
9
1-0180
3-571
4-670
76
11 536
30163
30-990
42
10838
16-664
17126
8
1-0160
3174
3*262
75
1-1515
29 757
30-582
41
1-0818
16-267
16-718
7
1-0140
2*778
3-854
74
1-1494
29-361
30174
40
1-0798
15-870
16-310
6
1*0120
2-381
3447
73
1-1473
28-964
39-767
39
1-0778
15 474
15-902
5
1*0100
1-984
2*039
72
1-1452
28-567
29-359
38
1-0758
15*077
15-494
4
1-0080
1*588
2-631
71
1 1431
28-171
28-951
37
10738
14-680
15087
3
1*0060
1*191
1-224
70
1-1410
27-772
28-544
36
1*0718
14-284
14-679
2
1-0040
0*795
1-816
69
1-1389
27-376
28*136
35
1*0697
13-887
14*271
1
1*0020
0*397
1-408
68
1 1369
26-979
27*728
34
1*0677
13-490
13-863
67
11349
26*583
27-321
33
1-0657
13-094
13-456
HYDROCYANIC ACID. Sjn. Cyanhydric acid, Prustic acid, C*NH. Th»
highly important acid is regarded by all chemists as being formed on the exact type
of the ordinary inorganic hydracids, such as the hydrochloric or hydriodie. The
compound radical analogous to chlorine, which is contained in it has received the
name of cyanogen, and possesses the formula C*N. That this body is precisely
analogous in its relations to the simple salt radicals is rendered certain by numerous
facts. It combines directly with metals to form compounds ; it possesses the same
Tapour volume, and unites with hydrogen to form a hydfacid, which in its torn
decomposes the metallic oxides with formation of water. Thus we have, with metallie
oxides and hydrochloric acid (M standing for a metal), MO + HCl»MCl-h HO, and
with hydrocyanic and metallic oxides (Cy standing for cyanogen), M0+ HCy»MCy
+ HO. Two volumes of chlorine and two of hydrogen yield four volumes of hydro-
chloric acid gas, and two volumes of cyanogen with two of hydrogen yield four
volumes of hydrocyanic acid. The density of the vapour of hydrocyanic acid is
consequently 0-9476. The theoretical number being 0*9342. Its density in the floid
state is 0*6967 at a temperature of 64*4°. It hoik at 80° F. at ordinary pressures
Hydrocyanic acid b never prepared in the anhydrous state except as a curiosity
or for the purpose of scientific investigation. In &ct it cannot be long preserved of
great strength; a somewhat complex decomposition invariably taking place in it,
with production of brown adhesive matters containing cyanide of ammonium, and
also a substance by some considered to be an acid, and known as the axulmic Para-
cyanogen is probably formed at the same time. The constitution of axulmic acid is by
no means well known, and even its very 'existence, as a definite chemical substance,
is doubtfoL It is singular that the presence of a mineral acid greatly retards the
decomposition of pmssic acid, especially if it be dilute ; the pharmacopoeian acid conse-
quently may be preserved of uniform strength, in well filled and closely stoppered
HYDROCYANIC ACID, 4S5
bottles, for almost any length of time. The deadly natore of prossic acid wihappily
causes it to be only too A'cquently resorted to by the despairing or the mnrderer.
Fortunately, however, in spite of its volatility, the chemist possesses excellent means
for its detection.
Preparatiom — I. Hydrated acid. As pmssie acid is largely employed in medicine,
but in a very dilute form, it is usual to prepare it and dilute until of the proper degree of
strength. The following process for preparing it will be foimd to give a satisfactory
result, and, moreover, it ma^ be performed on any quantity of materisds. llie apparatus
for the purpose will vary with the scale on which the experiment is to be made. If on
a few ounces, glass retorts and flasks answer well, if good condensation is ensured, by
means of a Liebig's condenser well supplied with very cold water. If a large quantity
of prussic aci<^i8 to be made, such as several gallons, the apparatus should consist of
a stoneware still, with head adjusted by grinding. The head should be capable of
adjustment with a stoneware adapter to a worm of the same material enclosed in a
tub of water. The joints are to be luted with a mixture of one handful of almond
meal and five handfiils of linseed meal, worked with water to the consistence of patty.
A solution of rough chloride of calcium in water is to be made and placed in a large
iron pot, with a cover so contrived as to permit the still to drop in up to the flange.
10 parts of yellow prussiate of potash are then to be bruised in a mortar and mixed
with dilute sulphuric acid prepared by adding 6 parts of sulphuric acid (density 1*850)
to 42 of water. The head being luted on, a fire is to be kindled in the furnace
under the iron pot, and the chloride of calcium bath is to be kept boiling constantly
until 36 parts of acid have distilled over. The beak of the still should be placed in
the funnel which conducts the acid to the Winchester quart bottles which are to
contain the product, and a piece of wet bladder is to be stretched over the funnel to
prevent evaporation of the acid into the laboratory. The worm used for the pnrpose
must be ascertained to be perfectly clean, and, if pmssie acid is to be frequently made,
should be kept specially for that operation. To each Winchester quart of the acid
distilling over, one drop of sulphuric acid may be added to insure its keeping. But
the acid thus prepared generally keeps for a long time even without this precaution,
owing probably to smsli traces of the sulphuric acid being carried over during the
distil&tion.
It is quite impossible to conduct the operation so as to yield a product of uniform
strength ; it is absolutely necessary, therefore, to determine the percentage of real
hydrocyanic acid, and dilute it to the required degree. It fortunately happens that
1 grain of hydrocyanic acid yields almost exactly 5 grains of cyanide of silver r for
one equivalent of acid » 27 produces 1 equivalent of cyanide of silver »134 ; so that
27 : 134 : : I : 4*96. The acid produced will have, probably, to be reduced to one of
two standards; namely, the so-called Scheele's strength, containing 5 per cent, of acid, or
the P.L., containing 2 per cent ; 100 grains of the former should, consequently, yield
25 grains, and 100 of tbe P.L. 10 grains of cyanide of silver. In either case the cal-
culation becomes obvious.
2. The anhydrous acid. Several processes for conducting this dangerous operation
are known ; the following is, perhaps, the most generally convenient A large glass
retort is so arranged that its neck is directed upwards at an angle of about 45^;
a cork fitted to the aperture in the neck connects a glass tube with a bottle containing
a little chloride of calcium. From the latter vessel another tube proceeds to a U tube
containing fragments of chloride of calcium, and from the latter a third, conducting
the dehydrated vapour of prussic acid to an upright glass tube contained in a mixture
of ice and salt Into the retort is Disced a mixture of 10 parts of yellow prussiate of
potash, 7 of oil of vitriol, and 14 of water. The retort is to be heated with a charcoal
fire, and the temperature of tiie bottle and U tube, containing the chloride of calcium,
is not to be allowed to fall below 90^, in order to prevent condensation of the anhy-
drous prussic acid taking place anywhere except in the ^be contained in the freezing
mixture. The vapour of anhydrous prussic acid is so dangerous that the greatest
precaution must be taken to prevent inhaling the smallest portion.
Detection of prusgic acid.'^When prussic acid exists in moderate quantity in a
solution it may be detected by first adding a few drops of potash, then a mixture of
protosulphate and persulphate of iron, and finally a little hydrochloric acid ; a bright
blue precipitate indicates the presence of the acid. A much more delicate test, and
one that is applicable when, from the dilution of the solution, the salts of iron are no
longer capable of acting, is by the conversion of the prussic acid into sulphocyanide
of ammonium. For this purpose the prussic acid is to be warmed on a watch glass
with a drop of sulphide of ammonium, until the solution has become colourless. The
addition of a trace of a solution of a persalt of iron will show, by the formation of a
blood red colour, the presence of the acid sought A very neat mode of applying
this test is to place one drop of sulphide of ammonium on a watch glass inverted over
Ii3
486 HYDROSTATICS.
another containing the sospected fluid. On leaving the apparatus in a warm plae^
arranged in this manner, for a short time, the upper glass will he found to contain
sulphocyanide of ammoninm, which, after drying, will be in a state well adapted fiar
showing the reaction with a persalt of iron. — C. G. W.
HYDRODYNAMICS. The mechanical science which treats of the nftotion of
fluids. This science has, of course, most important bearings on the pumping-engines,
water-wheels, &c., employed to (kcilitate the operation of the miner. It is not how-
ever possible to embrace this, which belongs to mechanical engineering, in this work.
HYDRO -EXTRACTOR. A name sometimes gi?en to tibe machines employed
for expelling the water from woven goods. See Desiccation.
HYDROFLUORIC ACID. It was observed by Scwankhardt, in 1670, thatflmr
spar and oil of vitriol would eat into glass. Scheele, in 1771, detemyned that this
peculiar property was dae to the liberation of an acid from the fluor spar.
Hydrofluoric acid is best obtained by placing finely powdered fluor spar in a leaden
retort, and twice its weight of highly concentrated oil of vitriol. By a gentle heat
the gas is distilled over, which must be collected in a leaden tube, in whieh« I7 means
of a freezing mixture, it may be condensed into a liquid. If a solution of this acid in
water is required, the extremity of the tube from the retort is carried into a vessel of
water.
Hydrofluoric acid attacks glass with great readiness, by acting on its silica.
Glass upon which any design is to be etched, is covered with an etching; wax, and the
design ma^e in the usual manner; this is placed over a leaden vessel, in which is a
mixture of fluor spar and oil of vitriol ; a gentle heat being applied, hydrofloorie
acid escapes, and immediately attacks the glass. See Fluobink.
HYDROGEN. (Eng. and Fr. ; Wasserstoff, Germ.) A permanently gaseous^ ele-
mentary body, the lightest of all known substances, its specific gravity being *0693 ; 100
cubic inches weighing, under ordinary pressure and temperature, only 2-14 grains;
It is therefore nearly 14*5 times lighter than atmospheric air.
From its extreme lightness it was formerly used for filling balloons, but has been
superseded for that purpose by ordinary coal gas, which can be obtained at a mnch
cheaper rate : the difference of buoyant power being compensated by increasing eon-
siderably the size of the balloon. It is itself inflammable, but not a supporter of com-
bustion, its combination with oxygen forming water, which contains ^th of its wei^t
of hydrogen.
It is generally prepared by the action of dilute sulphuric acid on zinc, although
these are many other processes which furnish it ; as the decomposition of steam by
iron filings with the aid of heat, &c
In the act of combining with oxygen, as when burnt in the oxyhydrogen blow-
pipe, the greatest possibla heat is obtained ; a piece of stout platinum wire being fused
when placed in the flame, which cannot be effected by the greatest heat attained in
our furnaces.
Hydrogen is sometimes used for soldering metals ; in which process it is requisite
to bring the two surfaces of the metal together in a perfectly metallic state at a high
temperature. Hydrogen effects this completely ; by its combustion it supplies the
heat, and by entering into combination with the oxygen of the air, prevents the for-
mation of oxides, which are so easily formed at the temperature required for the
melting of the metals, and which, when present, prevent the union of the sur&oes.
See Autogenous Soldering.
Hydrogen is often used also for the reduction of metals from their different 00m-
binations ; the reduction is effected by passing a current of hydrogen over the com-
pounds heated to redness. *
Its use in reducing ores on the large scale has been proposed, but as yet not found
practicable. — H. K. B.
HYDROMETER. An instrument for ascertaining the specific gravities of liquids.
Baume*s hydrometer, which % much used in France, and other countries of the con-
tinent of Europe, when plunged in pure water, at the temperature of 58^ Fahr., marks
0 upon its scale ; in a solution containing 1 5 per cent of common salt (chloride of
sodium), and 85 of water by weight, it marks 15^; so that each degree is meant to
indicate a density corresponding to one per cent of that salt See Ai/}ohoiji£TRT
and Areometer. *■
HYDROPHANE. A variety of opal which readily imbibes water, and when
immersed it becomes transparent, though opaque when dry. It is found in Hungaiy,
and in Ireland, near the Giant's Causeway, and at Crosreagh, Ballywiliin.
HYDROSTATICS. The science which treats of the equilibrium of fluids, and of
the pressure exerted by them.
In the engineering arrangements by which water is supplied to towns, hydrostatics
becomes of the utmost importance. The highest possible level is obtained for the
HYPOSULPHITES. 487
reserroir; and ih>iii this ft series of pipes is arranged through all the streets and
houses. The tendency of the water is to rise to its original leyel, and hence all the
pipes are filled with water, and in all such as are below the level of the water in the
reservoir a pressure upward is exerted e<^ual to Uie height of the reservoir above
that point ; and if a hole is pierced in the pipe, the water jets out with a force equal to
this pressure. In the highest houses, the water perhaps only finds its level, and
flows out withont pressure quickly. See Water Pbbssuab Ekoinbs ; Htdbaulic
Cbanx.
HYDROSULPHURETS. Chemical compounds of bases with sulphuretted hydro-
gen, or hydrosalphoric acid.
HYMGN<E A COURBARIL. A tree growing in South America, from which the
TCflin amimi exudes.
HYPEROXYMURI ATEa The old and incorrect name of CHiiORATEa
HYPOCHLORIC ACID. CIO'. £q. 67*5. When fineljr powered chlorate of
potash is gradually mixed into a paste with strong sulphuric acid, and heated in a bath
of alcohol and water, a yellow gas is disengaged which is this hypochioric acid, or the
peroxide of chlorine. Although of much mterest as a chemical compound, it has no
use in the arts. See l/re'e Chemical Dictionary.
HYPOCHLOROUS ACID. CIO. £q. 43*5. This acid is best obtained by diffusing
red oxide of mercury finely divided through twelve times its weight of water, which
is introduced into a bottle containing chlorine, and agitated until the gas is absorbed.
An oxychloride of mercury is formed, which is removed by subsidence. The weak
fluid obtained b put into a flask, and heated in a water bath, when the evolved gas is
collected in a smaller portion of water, which becomes a pure solution of hypochlorous
acid.
The salts are termed hypochlorites. See Chlorine and Bleachino.
HYPOSULPHATES. Saline compounds formed by the union of hyposulphuric
acid with bases.
HYPOSULPHITES. Saline compounds formed by the union of hyposulphnrous
acid with bases.
Hypoeulphau of Soda, The salts of the hyposulphuric acid are obtained from the
hyposulphate of manganese, which b itself thus prepared : finely divided binoxide of
manganese b suspended in water, artificially cooled, and a stream of sulphurous acid
passed through it The binoxide gives up half its oxygen, becoming protoxide,
which unites with the hyposulphuric acid which b formed, producing the soluble
hyposulphate of manganese^ which b separated from the excess of binoxide by filtra-
tion.
OThe f<^wing equation represents the reaction : —
MnO» + 2S0« « MnO,S«0».
If the temperature were allowed to rise, sulphuric acid would be formed, and not
hyposulphuric : —
MnO* + S0» - MnO,SO>.
The hyposulphuric acid, unlike the hyposulphnrous acid, may he obtained in the
free state, and its solution permits even of being evaporated in vacuot until it acquires
the density of 1*347 ; but if carried further, it b decomposed into sulphuric and
sulphurous acids.
The acid b obtained in the ft^e state by adding baryta water to the hyposulphate
of manganese; the soluble hyposulphate of baryta, filtered from the oxide of man-
ganese, and precipitated exactly by the cautions addition of sulphuric acid, and fil-
tered from the precipitate of sulphate of baryta, yields the pure solution of the acid,
which may be evaporated in vacuot as above stated.
It has no odour, but a very sour taste.
The hyposulphate of soda may be made directly from the manganese salt or from
the free acid.
All the hyposulphates are soluble ; they have not as yet met with any commercial
application.
Hyposulphite of Soda. Thb salt, now so extensively used for photographic pur-
poses, was first introduced by Sir J. HerscheL It may easily be prepared by the
following process : via. by ti'ansmitting through a solution of sulphide of sodium
(prepared by fusing together in a covered crucible equal weights of carbonate of soda,
and flowers of sulphur), a stream of sulphurous acid until it ceases to be absorbed ;
the liquid is then filtered and evaporated, when the hyposulphite of soda (NaO,S^O'
•¥■ 5H0) crystallises out.
Another and perhaps better process consists in digesting a solution of sulphite of
soda oo flowers of lulphor. The sulphur gradually dissolves, forming a colourless
ii4
488 ICEHOUSE.
fiolation, which yields on evapoTatioii crystals of hyposulphite of soda ; the
being shown by the following equation : —
NaO,SO» + S = NaO,S'0«.
The baryta salt may be obtained in small brilliant crystals, by mixing dilate
solutions of chloride of barium and hyposulphite of soda.
The hyposulphurous acid is incapable of existing in the free state, for almoci imme-
diately on the addition of an acid to the solution of its salts, it is decomposed into
sulphurous acid, with liberation of sulphur. (S^'O' » SO* + S.)
The soluble hyposulphites have the power, in a marked degree, of dissolving certain
salts of silver, as the chloride, iodide, &c, which are insoluble in water ; forming
with them soluble salts, whose solutions possess an intensely sweet taste, although
the solutions of the hyposulphites alone possess a disagreeable bitter taste.
From the above reaction arises the principal value of the hyposulphite of soda,
which is used by the photographer to dissolve off from the photograph, after the
action of the light on it, ail the undecomposed silver salt, thus preventing the further
action of the light on the picture.
A double hyposulphite of soda and gold is used for gilding the daguerreotype plate,
and for colouring the positive proof obtained in photographic printing, Thia double
salt may be obtained in a state of purity, by mixing concentrated solutions of 1 part
of chloride of gold, and 3 parts of hyposulphite of soda ; by the addition of alcohol it
is precipitated ; the precipitate must be re-dissolved in a small quantity of water,
and again precipitated by alcohoL Its formation is explained by the following eqiut-
tion: —
8(NaO,SK)')+ AuCT- 2(NaO,S«0» + AuO,S«0«,3(NaO,S»O«) + 3NaCL
« ^ » « — ^
TetratbioDftte of Hypocolpbite of soda and gold. Chlor.
soda. of sodiuB.
H.K.&
HTSON. A green tea. See Tea.
L
IBEX. An animal of the goat kind, the hair of which is esteemed for some kirds
of manu^Lcture.
ICEHOUSE. (Glaciere, Fr. ; Eishatu, Germ.) Under the article Freezing, the
different artificial methods of producing cold are enumerated. But for the uses of com-
mon life, in these climates, the most economical and convenient means of refrigeration
in hot weather may be procured by laying up a store of ice in winter, in such cir-
cumstances as will preserve it solid during summer.
An icehouse should not be regarded as an object of mere luxury ; in the southern
countries of Europe it is considered among people in easy circumstances as an indis-
pensableappendage to a country mansion. During the dog days, especially at those
periods and in those districts where the sirocco blows, a lassitude and torpor of mind
and body supervene, with indigestion or total loss of appetite, and sometimes dysen-
teries, which are obviously occasioned by the excess of heat, and are to be prevented
or counteracted chiefly by the use of cold beverages. By giving tone to the stomach,
iced driuks immediately restore the functions of the nervous and nuscular systems
when they are languid ; while they enable persons in health to endure without much
inconvenience an atmosphere so close and sultry as would be intolerable without this
remedy. Icehouses, moreover, afford to country gentlemen a great advantage in
enabling them to preserve their fish, butcher meat, dead poultry, and game, which
would otherwise, in particular states of the weather, immediately spoil. Considering
at how little expense and trouble an icehouse can be constructed, it is surprising that
any respectable habitation in the country should not have one attached to it. The
simplest and most scientific form is a double cone, that is, two cones joined base to base ;
the one being of stones or brick-work, sunk under ground, with its apex at the bottom,
into which the ice is rammed ; the other being a conical roof of carpentry covered
with thatch, and pointed at top. The entrance should be placed always on the north
side ; it should consist of a corridor or porch with double doors, and be screened
from the sunbeams by a small shrubbery. Such are the principles upon which an
icehouse should be formed ; but they will be better understood by the following ex-
planation and figure.
A dry and sandy soil if possible should be selected ; and here a cavity is to be dog
about 16 feet in diameter, terminating below like the point of a sugar loaf. Its
ICELAKD UOS& 489
onliiurj depth for a fkmilj may be abont St feet ; bnt the larger ill dimeniioDi are,
tbe longer vill it preMrre ihe ice, provided it be filled. In digging, the workman
(hould slope the ground progressively towards the siie of the cone, to preieot the
ewth falliag in. This conical slope ahoold be fluied with brick or ilone work about
one fiiot thick, and jointed with Roman cement, so ai to be air and water-light A
well is lo be eieaialed, al the botlom 3 feet wide and 4 deep, covered at top with an
iron grating for supporliDg Ihe ice, and letting the water drain away.
The Bpper cone may likewise be built of briclc-work, and covered with thatch ; laeh
a roof vronld prove the molt dumble. This is tbe constmetioD shown injlji. 9S4.
Whatever kind of roof be preferred, there must be left in it an oblong passage into
the inlerior. This porch shonld face the north, and be at least S f^t long by 9} fbet
wide i and perfectly closed by a wcU-itlted door at each end. All round the bottom
of this eooical cover, a gutter shonld be placed to carry off Ihe rain to a distance
from the icehonse, and preveat tbe circumjacent ground from getting soaked with
Fig. 995 shoini the aectioa of a well-constructed icebooie. Under the ice eham*
ber * the ice is rwnmed into the space B. e is the grata of the drain sink n. The
portion e e is built in brick or stone ; the base L of the ice-chamber slopes inwards
toiardi the centre at c. The upper part of the brick-work E sis a little way beltnr tbe
level of the ground. The wooden tVamework
1 1 J r forma the roof, and ii covered with thick
thatch, o B is the wooden work of the door i. At
K the backet is seen (or lifting up a charge of ice,
by means of the cord i passing over Ihe pulley M,
which enables the servant to raise it easily.
Tbe icehonse should have Qo window to admit r
light ; bat be, 10 to speak, hermetically sealed in :
every point, except at its cesspool, which may ;
tenninnte in a water trap to prevent circulation of
A clear day should be selected for charging the ,
icehoose -, but before beginning id All, a qnaotity :
of long dry straw shoold be laid on tbe bottom [
croSKwiee-, and as the Ice is progressively iotrodueed, ^
atraw is to bespreadagainslthe conicalsides,lopre- <
vent the ice from coming into contact with the brick
or stone-work. The mote flrmlj compacted the ice i.
is, the better does it keep ; with which view it should ?
be broken into pieces with malleu before being j
thrown in. No Uyers of straw should be atratified '
among Ihe iee, for they wonld make its body poraua. -
Some persons recommend to pour in a little water
with the successive layers of ice, in order to fill np its small crevices, and convert the
whole into one mass.
Over the top layer a thick bed of straw should be spread, which is to be covered
with board) surmoonled with heavy ilones. to close up the interstices in the straw.
The inner and outer door should never be opened at once ; but the one should always
be shut before the other is opened.
Dry snow well rammed keeps equally well with hard iee, if care be taken to leave
no cavities in the mass, and tosecute its compaclncu by sprinkling a little water upon
the SQCcettive charges.
To facilitate the extraction of the ii^e, a ladder is set up against its sloping wall at
one aide of the door, and left there daring the season.
ICE BT THE RED-HOT PR0CE8& See Spseboidai. Statb.
ICE-PROnUCINQ MACHINE. See FHEEzreo.
ICELAND MOSS (XwAn tf/ilaiidt,Fr.; Flechte lit. Germ.) is a lichen, tbe Ce-
iraria Iilaadica, wbicb contains a subelance soluble in hot water, bat forming a jelly
when it cools, styled lichmiite by U. Querin. This moss is called in the Pharma-
copin Lichat liandicta. It appears lo have derived iti name from the circumstance
that the Icelanders first discovered its medicinal qualities. Liehenine is prepared by
extracting first of all fram the plant a bitter colouring matter, by digesting 1 pound i»
it in i 6 pounds of cold water containing one ooDce of pearl-aah; Ihen draining the
lichen, edulcorating with cold water, and boiling It in 9 pounds of bailing water, till
3 pounds be evaporated. The jelly which Ibrms. upon cooling the filtered solution,
is dark coloured, but, being dried and reSIssolved in hot water, it becomes clear and
colourless. Liehenine consists of 39'33 carbon, 7-3< hydrogen, and G5-43 oxygen.
The mocilage of Iceland moss is preferred in Germany to common paste fbr dressing
490 ILLUMINATION.
the irarp of webf in the loom, because it remains toft, from its hygrometrie quli^.
It is also mixed with the palp fbr sizing paper in the vat For sereral carious eom-
ponnds obtained from Iceland moss, see c/ire's Chemical Dktwnary.
ICELAND SPAB. Crystallised carbonate of lime, of which the most beantifia
specimens are bron^ from Iceland. These are remarkable for thdr doable refne-
.tion ; and hence this crystal is sometimes called double refracting ^par.
IDW ALE-STONE. A peculiar Welsh hone stone. It is obtamed from the older
slate rocks of the Snowdon district
ILIXANTHINE. A snbstance which might be employed for dyeing yellow,
derived from the leaves of the common holly.
ILLUMINATION. The means of determining the rdative vahua ofvarioue nomrcee
of Ubiminating power.
It is often of the utmost importance that we should be enabled, with fiicUity, to
determine the relative values of the light which we obtain from artificial soarees^
The only way in which this can be effected, is by comparing with some standard
source of light the illuminating sources employed. Dr. Ure, who was on several
occasions called on to direct his attention to inquiries of this nature, institated many
very ingenious and exact experiments ; to some of these it appears important that we
should direct especial attention. Of the original paper on the cost of illnmiiwition,
manv parts are now obsolete; but as much of it is still of considerable practical Talne,
the following selections have been made, all such being distinguished by Dr. Ure*s
name. After many experiments to determine a standard. Dr. Ure says : —
** After comparing lights of many kinds, I find every reason to conclude that a large
wax candle of three to the pound, either long or short, that is, either 12 or 15 inches
in length, as manofkctured by one of the great wax-chandlers of London, and fisr*
nished with a wick containing 27 or 28 thr^ids of the best Turkey cotton, is capaUe
of fumishinff a most uniform, or nearly invariable standard of illimiination. It affords
one tenth of the light emitted by one of the Argand lamps of the Trinity House, and
one-eleventh of the light of my mechanical lamp, when each lamp is made to bora
with its maximum flame, short of smoking.*'
Dr. Ure, however, for many of his determinations employed the French nMw>h«nM-i
lamp, known as Carcel*s lamp ; and in connexion with this the following renaarks
occur : —
*' Mr. Samuel Parker, long advantageously known to the public Ibr his siniimhral
and pneumatic fountain lamps, as well as other inventions subservient to domcstie
comfort, having obtained a patent for a new lamp, in which the oil is heated by a veiy
simple contrivance, in the cistern, to any desired degree, before arriving at the wick,
I instituted an extensive series of experiments to determine its value in the prodoction
of light, and consumption of oil, compared to the value of other lamps, as well as
candles, in these respects.
Jn Jig. 986 ▲, A, B, B, is a section of the cylinder which constitutes the cisters ;
the oil being contained between the inner and outer cylinders, and receiving heat fivm
the flame of the lamp which passes up through the inner cylinder, and is rever-
berated more or less against its sides by the top of the metal chimney being notched
and bent back, d is a slide-vaWe, which is opened to allow the oil to descend to the
wick, and is shut when the cistern is to be separated from the pipe of supply, at a,
for the purpose of recharging it with oiL The flame is modified, not by raising or
lowering the wick, ss in common lamps, but by raising or lowering the bell-moathed
glass chimnev which rests at its bottom on three points, and is moved by means of
the rack- work mechanism f. The concentric cyUndric space a, ▲, and a, a, contains
a pint imperial, and should be made entirely full before lighting the lamp ; so as to
leave no air in the cistern, which, by its expansion with Sie heat, would inevitably
cause an overflow of the oiL
The following arrangement was adopted in these experiments for determining the
relative illumination of the different lights. Having trimmed, with every precaution,
my French mechanical lamp, and charged it with pure sperm oil, I placed it upon an
oblong table, at a distance of 10 feet from a wall, on which a white sheet of paper was
stuck. One of Mr. Parker's Aot-oil lamps, charged with a quantity of the same oil,
was placed upon the same table ; and each being made to bum with its maximum
brilliancy, short of smoking, the relative illumination of the two lamps was determined
by the well-known method of the comparison of shadows ; a wire a few inches long,
and of the thickness of a crow-quill, being found suitable for enabling the eye to esti-
mate very nicely the shade of the intercepted light It was observed in numeioiM
trials, both by my own eyes and those of others, that when one of the lamps was
shifted half an inch nearer to or further i^m the paper screen, it caused a peroeptihle
difference in the tint of the shadow. Professor Wheatstone khidly enabled me to ftantf
the precision of the above method of shadows, by employing, in some of the ezpen*
ILLUMINATION. 491
inenia, a photomrter of hU own uiTention, in vUch the relUive briabtncM of th« tiro
lighu iru deteimined bj the relatiTe brigbtDew of the sppoeile tidei of m rcTolTmg
silTCKd ball, illomiaiiri bj them.
at the ba«e, and 1-9 at top « the vide bottom part v
upper i«it 8 iochM. When placed at adiatanoeoflOfeetAom the wall in light then
laay be eMimated ai tbeaqure of thtinamber, or 100. In the flrtt eeriei ^ eiperi'
neol*, when baniing with iu maxunmn flane, with oeeaaiimal flickeriun of moke,
it emilled alight equal to that of II wax candlei, and eotuomed 913 gma§ of oil per
honr. The Iperm oil w»» quite pnre, haTing a •peoifle gimTity of 0-874 compurd to
Tatar at 1 000. In a wbeequeot wriei of eiperimenti. Then its Ught wai len flickering,
BDdeqsal only to that of 10 Tax caodlea, it ccHuamed onl; BlSgraiai, orO 1164 of a
lb. per honr. If we mnllipl; thii aumber mto the priec of the oil (6t. per gallwi)
per lb. llii, the prodnet \-2S04iL will npreseut the relative ooM of this illnminatioe,
3. The hot-inl lamp bnmi with a much cteadter flame than the mechanical, which
nut be aacKbed in no anull degree to the ronnded elope of the bell-nioDth«l glaaa
chimney, wberebj the air ii brought progreeaiTei; ckner and cloeer into oonlaet with
the cater tnrhoe ofthe flame^ wiuoot being ftarioulj daaW agkioat it, aa tt i* b; the
rectangnlar dionlder of the eominon contracted ctumncj. When charged with eperm
oil, and made to bnra with itt maximnm flame, thii lamp reqnired to be placed one
IbM fOrtber fron the acraeo than die mechanical lamp, in order that ita ihadowdioald
have the eime depth of tint Hence, ita relatiTe Ulomination waa, in that eaae, as the
•qnara of 11 to the aqnara of 10; or u ISI to loa Yet ita eoaaamptiaii of oU waa
tu\j S9S grains, or aomewhat leia than O-I of a lb. per honr. Had ita light been
reuKed to 100, it woedd have eonaomed ont; B76 grain* per honr, or -OSS of a lb. If
we mnHi^ thia number bj IXd, the product 0-*02(£ will repreaent the rdatire eoM
of 100 of thia iUomination.
3. The hot-oil lamp being charged with the aonthem whale oil, of epeeifla griTity
0-9Sft, at £(. 6d per gallon, or Sfk. per lh„ when bnmLnff with ita maximum flune,
Nqnired to be placed 9 feet and 1 inch framlheicreen todroptheiame tintof ahadow
won it *a the flames of the other two lamps did at 10 and 11 tttt with the aperm oil.
The aqoare of 9 ftet and 1 iiich~S3 is the reluire illumination of the hot-cnl lamp
492 ILLUMINATION.
with the soathern whale oiL It consumed 780 grains, or 0*111 of a poand per hour;
but had it given 100 of light it would have consumed 911 grains, or 0*130 of a poaod,
which number being multiplied by its price 3jd!., the product 0*48 7 SdL will represent
the relative cost of 100 of this light
4. A hot-oil lamp charged with olive oil of specific gravity 0-914, at 5«. 6dL per
gallon, or 7|dl per lb. when burning with its mazimnm flame, required to be placed
at 9 feet 6 inches, to obtaiii the standard tint of shadow upon the screen. It ooa*
sumed 760 grains per hour. The square of 9^ feet is 90^, which is the relative inten-
sity of the hght of this lamp. Had it emitted a lights 100, it would have consamed
840 grains, or 0*12 of a pound per hour — which number multiplied by the price per
pound, gives the product 0*9</. as the relative cost of 100 of this light.
5. A hot-oil lamp charged with Price and Co.'s cocoa-nut oil (oleine), of specific
gravity 0*925, at 4s. Bd. per gallon, or SjdL per lb., had to be placed 9 feet from the
screen, and consumed 1085 grains per hour. Had its light been 100 instead of 81 (9^
the consumption would have been 1277 grains, or 0*182 of a pound per hoar ! which
number multiplied by its price per pound, the product I'OSldL will represent the eost
of 100 of this illumination.
6. In comparing the common French annular lamp in general use with the me-
chanical lamp, it was found to give about one-half the light, and to consume two-thirds
of the oil of the mechanical lamp.
7. Wax candles from some of the most eminent wax-chandlers of the metropolis
were next subjected to experiment ; and it is very remarkable that, whether they were
threes, fours, or sixes in the pound, each afforded very nearly the same quantity of
light, for each required to be placed at a distance of 3 feet fh>m the screen to afford
a shadow of the same tint as that dropped fh>m the mechanical lamp, estimated at 1(Ml
The consumption of a genuine wax candle, in still air, is, upon an average of many
experiments, 125 grains per hour, but as it affords only -fj of the light of the me-
chanical lamp, 1 1 times 1 25 « 1375 grains, or 0*1064 of a pound is the quantity that
would need to be consumed to produce a light equal to that of the said lamp. If we
multiply that number by the price of the candles per lb.»30<2. the product =5*892<i.
is the cost of 100 of illumination by wax. A wax candle, three in the pound (short),
is one inch in diameter, 12 inches in length, and contains 27 or 28 threadSt each
about -ff of an inch in diameter. But the quality of the wick depends upon the capil-
larity of the cotton fibrils, which is said to be greatest in the Turkey cotton, and
hence the wicks for the best wax candles are always made with cotton yam imported
firom the Levant, A wax candle, three in the pound (long), is } of an inch in diameter,
15 inches long, and has 26 threads in its wick. A wax candle, six to the pound, is 9
inches long, } of an inch in diameter, and has 22 threads in its wick. The light
of this candle may be reckoned to be;, at most, about ^ less than that of the threes in
the pound. A well-made short three burns with surprising regularity in still air, being
at the rate of an inch in an hour and a half, so that the whole candle will last 18 hoars.
A long three will last as long, and a six about 9} hours. 8p. gr. of wax ■» 0*960.
8. A spermaceti candle, three in the pound, is •^ of an inch in diameter, 15 inches
long, and has a plaited wick, instead of the parallel threads of a wax candle. The
same candles four in the pound, are ,^ of an inch in diameter, and 13} inches long.
Each gives very nearly the same quantity of light as the corresponding wax candles :
vis. -|lf of the light of the above mechanical lamp, and consumes 142 grains per hour.
Multiplying the last number by 11, the product, 1562 grains » 0*223 of a pound, would
be the consumption of spermaceti requisite to give 100 of illumination. Multiplying
the last number by 24dl, the price of the candles per pound, the product, 5 352dL is the
relative cost of 100 of this illumination.
9. Stearic acid candles, commonly called German wax, consume 168*5 grains, or
0*024 of a pound per hour, when emitting the same light as the standard wax candle:
Multiplying the latter number by 11, and by ISd. (the price of the candles per lb.), the
product 4'224d. will represent the relative cost of 100 of this illumination.
10. Tallow candles : moulds, short threes, I inch in diameter, and 12} in length ;
ditto long threes, -f^ of an inch in diameter, and 15 in length; ditto, long fours, ^ of
an inch in diameter, and 13} in length. Each of these candles bums with a most nn^
certain light, which varies ft-om ii!! to <^ of the light of the mechanical lamp — the average
may be taken at -^. The threes consumes each 1 44 grains, or 0*2 of a pound, per hour ;
which number, multiplied by 14, and by 9d, (the price per pound), gives the product
2-52(/. for the relative cost of 100 of this illumination.
1 1. Palmer^s spreading wick candles. Distance from the screen 3 feet 4 inches^
with a shadow equal to the standard. Consumption of tallow per hour 232*5 grains,
or 0 0332 of a pound. The square of 3 feet 4 inches » 11*9 is the relative illumina-
tion of this candle»ll*9 : 0*3332 :: 100 :0-2S x 10d:«ll-9 is the relative cost of
this illumination. *
ILLUMINATION.
493
12. Cocoa-nat stearine candles consumed each 168 grains per hour, and emitted a
light equal to 1^ of the standard flame. Multiplying 168 hy 16, the product 30*88
grains, or 0*441 of a Ih., is the quantity ^hich would be consumed per hour to afford
a light equal to 100. And 0*441 maltiplied by lOd., Uie prioe per lb., gives the pro-
duct 4*441dl as the cost of 100 of this illumination per hour.
IS. A gas Argand London lamp, of 12 holes in a circle of f of an inch in diameter,
irith a flame 3 inches long, afforded a light »78| compared to the mechanical lamp:
and Mtimating the light of the said mechanical lamp as before at 100, that of the
hot-oil lamp is 121, and that of the above gas flame 78*57, or in round numbers 80,
and the common French lamp in general use 50.
Collecting the preceding results, we shall have the following tabular view of the
cost per hour of an illumination equal to that of the mechanical lamp, reckoned 100,
or that of eleven wax candles, three to the pound.
Table of Cost per Hour of One Hundred of Illumination.
1. Parker's hot-oil lamp, with southern whale oil
2. Mechanical or Carcel lamp, with sperm oil
3. Parker's hot-oil lamp, with sperm oil
4. Ditto ditto common olive oil
5. Ditto ditto cocoa-nut oleine or oil
6. French lamp in general use, with sperm oil
7. Wax candles - - - . -
8. Spermaceti candles ....
9. (jlennan wax (Stearic acid) ditto
10. Palmer's spreading wick candles -
11. Tallow (mould) candles . . . ,
12. Cocoa-nut stearine of Price and Ca
PeDce.
0*4875 or about
1*2804 -
0-902 -
0-900 -
1031 -
1-7072 -
5-892 -
5-352 -
4*224 -
2-800 -
2*520 -
4*41
The following table contains, according to Peclet, the illuminating powers of dif-
ferent candles, and their consumption of material in an hour ; the light emitted by a
Coicel Argand lamp, consuming 42 grammes (b42 x 15| grains) in an hour, being
called 100: —
Tallow candles 6 in lb.
Stearine, or pressed tallow, 8 in lb.
^___^_ ^ 5 in lb.
Wax candles, 5 in lb. • -
Spermaceti, 6 in lb* -
Stearic acid, commonly called stearine,
5 in 11). - - - • -
Intencltj of Light.
Consunption per Hour.
10*66
8-74
7*50
13*61
14-40
14*40
8-51
7*51
7-42
8-71
8 92
9-33
The Sttlijoined table shows the economical ratios of the candles, where the second
column gives the quantity of material in grammes which is requisite to produce as
much li^t as the Carcel lamp:—
Tallow candle, 6 per lb. -
, 8 per lb. -
Pressed tallow, 5 per lb. -
Wax candle, 5 per lb.
Spermaceti ditto, 5 per lb.
j Stearine, 5 per lb. -
QUalitT of
UateriBl.
Price per Kilo-
Cott of Light per
gramme.
Hour.
70-35
If. 40 C
9-8 C.
85*92
If. 40 C
12*0 C
98*93
2f. 40 c.
23*7 C
64*0^
7 f, 60 c.
48-6 C
61*94
7 f. 60 c
47*8 c.
65*24
6£
371c
These results may be compared with mine given above. A kilogramme, or 1000
grammes » 1 5,440 grains « 2| lbs. avoirdupois. " — Ure,
The rule observed in the determination of these questions of illuminating power,
IS, according to the laws of optics, that the sum of the impinging rays from any
source* is inversely as the square of the distance from their source.
** The numerical estimation of the degrees of intensity of light constitutes that
btanch of optics which is termed Photoxetrt.
494 ILLUMINATION.
** If light be a material emanation, a something scattered in mmnte paitieles in an
directions, it is obvions that the same quantity which is diffosed orer the snrfiBoe of a
sphere concentric with the luminous points, if it continue its oonrse, will aocceanTelj
be diffused over larger and larger concentric spherical surfkces ; and then ita intensity,
or the number of rays which &11 on a given space, in each will be inversely as the
whole snrfSsices over which it is difhised ; that is, inversely as the square of their radii,
or of their distances from the sourceof light .... Let a candle be placed behind an
opaque screen, full of small equal and similar holes : the light will shine throng
tiiese, and be intercepted in all otber parts, formiog a pyramidical bundle of raya.
having the candle in the common vertex. If a sheet of white paper be placed behmd
this, it will be seen dotted over with small luminous specks, disposed exactly as thv
holes in the screen. Suppose the holes so small, their number ao great, and the eye
so distant from the paper, that it cannot distinguish the individual specks, it will still
receive a general impression of brightness ; the paper will appear illuminated, and
present a mottled appearance, which, however, will grow more uniform as the boles
are smaller and closer, and the eye more distant, and if extremely so, the paper will
apppar uniformly bright Now if every alternate hole be stopped, the paper will
manifestly receive only half the light, and will therefore be only half as much illomi-
nated ; and cateris paribus the degree of illumination is proportional to the namber of
holes in the screen, or to the number of equally illuminated specks on the suHace ; l e.
if the speck be infinitely diminished in size, and infinitely increased in namber to
the number of rays which fall on it from the original source of light** (HenduL)
Reasoning thus, Sir John Herschel proceeds and establishes the following definitions: —
The nud intrinnc brightne»$ of a luminous object is the intensity of the light of
each physical point in its surface.
The apparent inirifuic brightness of any object or luminary ia the degree of iUnmi-
nation of its image or picture at the bottom of the eye.
The absolute light of a luminary is the sum of the arcaa of ita dementuy povtians,
each multiplied by its own intrinsic brightness.
7^ apparent hght of an object is the total quantity of light which enters oar eyes
from it, however distributed on the retina.
Various instruments, called photometers^ have been devised to measave the iUnni*
nating power of any body ; these are, all of them, more or less defective, and the
results which we obtain with the best of them are merely comparative with each
other.
Bonguer*s photometer consisted of two surfaces of white paper, of exactly equal sise
and reflective power, cut from the same piece in contact ; these are illuminated, the
one by the light whose illuminating power is to be measured ; and the other by a
light whose intensity can be varied at pleasure by an increase of distance, and can
therefore be exacUy estimated. The variable light is to be removed or i^proached,
till the two surfaces are Judged to be equally bright, when the distances of the
luminaries being measured, or otherwise afiowed for, the measure reqoiied is
ascertained.
JRum/ortTs photometer. Before a screen of white paper, in a darkened room, is placed
a blackened cylindrical stick, and the two lights to be compared are so placed that
two shadows are thrown upon the screen side by side, with an interval between them
about equal in breadth to either shadow. The brighter flame must then be removed,
or the feebler brought nearer to the screen, till the two shadows appear of equal in*
tensity, when their distances from the lights must be measured, and their total illu-
minating powers will be in the direct ratio of the squares of the distances.
JRiichies photometer consists of a rectangular box, about an inch and a half or two
inches square, open at two ends. It is blackened within to absorb the extraneous
light Within, mclined at angles of 45° to its axis, are placed two rectangular pieces
of plain locking-glass, cut from one and the same rectangular strip ; these are fkstened
so as to meet in Ute middle of a narrow slit, about an inch long, and an eighth of an
inch broad, which is covered with a slip of fine tissue or oiled paper, and a blackened
card prevents the reflected images from mingling. If we would compare two lights,
they must be placed at such a distance from each other, and from the instrument be-
tween them, that the light from every part of each shall fall on the reflector next it,
and be reflected to the corresponding portion of the paper. The instrument is then to
be moved nearer to the one or the other, till the paper on either side of the division ap-
pears equally illuminated. When the lights are thus exactly equalised, it is clear that
the total illuminating powers of the luminaries are directly as the squares of their dis-
tances from the middle of the instrument
Wheatstone's photometer is a small sphere with a reflecting snrftoe, which being
placed between the two lights, each light is seen on it by the spectator, the two being
reflected from different points of the sphere's surface. By an iogenioos bat aimpie
IMPEBMEABLK
495
mechanical contrivance, a rapid looped motion is commonicated to tbe ball, and bj
the principle of tbe persistence of impressions, tbe spectator immediately sees two
looped curves of different brigbtnesses. The brighter light is removed mitil tlkese carves
aeem of tbe same brightness, and the intensities of tbe luminous points are then aB the
squares of tbe distances.
Bunsen's photometer consists of a sheet of cream coloured letter paper, rendered
transparent over a portion of tbe surface by a mixture of spermaceti and rectified
ziapbtha, which is solid at common temperatures, but becomes liquid on the application
of a yery gentle heat The mixture is liquefied and painted over the paper with a
brush, leaving a round disc of the size of half a erown m the centre uncovered. When
a light is placed on one side of the paper a dark spot is observed on the uncovered
portion. When another light is placed on tbe other side of the paper, the spot is still
distinctly visible, if the distance of the light is such that the reflected portion from ^e
paper be either of greater or of less intensity than that transmitted. When the paper is
so situated between the two flames that the transmitted and reflected light are of the
same intensity, tbe nncorered spot is no longer visible.
It will be eyident from these descriptions that it is possible only, by any of these
contrivances, to compare one light with another; there is not any arrangement by
which we are enabled to express absolutely tbe illuminating power. Upon the prin-
ciple of comparison, and comparison only, tbe following tables haye been constructed
by the relative Experimentalists. Tbe observations of P^clet have been already given.
The following comparative view of wax and stearine candles manufactured in Berlin,
which haye been deduced fW>m the observations of Schubarth, is of much value.
Kind of candlctf and whence obtained.
Relative
Intencity of
light.
Coniumption
tn one hour,
in frammet.
RelatiTe
Illttmlnatfaig
power.
Common wax candles, of
Tannhanser *
r4's
6's
8's
103-6
91-0
100-0
7-877
7-176
6-562
8520
83-20
1000
rvs
132-7
9*398
92*66
Wax candles, of Walker - <
6*s
120-3
8-082
97*69
,8'S
113-1
7132
104*1
r4's
117-4
9-427
81-74
Stearine candles, of Motard - •
6*8
8*s
111-8
121-0
9-383
7-877
78-28
100-7
Stearine candles, of Mag-
net and Oehmicben -
rvs
6*s
.8'8
139-5
132-7
1260
10-63
9*398
8-506
86-11
92*66
96-64
Stearine candles, firom tbe
same makers - - - '
r6's
8*s
1161
146*0
8-871
8*886
85-86
108-0
^
f4'8
124-5
9*880
82*67
Candles made firom palm oil • •
6's
Ls's
115*3
167-5
9178
8-813
82*66
118*70
These results show us that the mean illuminating power of wax and stearine
candles is nearly tJie same.
Tbe illuminating power of gases and of gas burners will be found in the article
CoAi. Gab,
IMPERMEABLE, is the epithet given to any kind of textile fabric, rendered
water-proof by one or other of tbe following substances ; —
1. Linseed oil to which a drying quality has been communicated by boiling with
litharge or sugar of lead, &c.
2. The same oil holding in solution a littie caoutchouc
3. Ayamiah made by dissolying caoutchouc in rectified petroleum or naphtha, applied
between two surfiiees of doth, as described under Macintosh's patent See Caoui^
cBoua
4. Vegetable or mineral pitch, applied hot with a brush, as in makmg tarpauling for
coyering goods in ships.
5. A solution of soap worked into doth, and decomposed in it by the action of a
solution of alum ; whence results a mixture of acid, fats, and alumina, which insinuates
itself among all the woolly filamentSi fills their interstices, and prevents the passage of
water.
6. A solution of glue or isinglass, introduced into a stuff, and then acted upon by a
dear infusion of gdls, whereby the fibres get impregnated with an insoluble, imper-
meable, pulverulent leather.
496 ISCUBATION.
7. Plttfter Tork it Kndered impenne&ble bj miziag artiEciil or natoral Mphaltnn
INCUBATION, ARTIFICIAL. The Egyptians ha^e ft™n time intmeinorial
been acciutonied to hatch cagt by arltficial irarniih. wiihnut the aid of heni, in pr-
coliar gloTCS, called 3fainiRiija. M. dc Heaumur pabliihed in France, aboal acmtniy
ago, some iagenioDS observBtioni upon this luhjecl ; but M. Bonn^malD vu the firat
person who iludied vitb dae attention bU the circum«laiice> of artiGcial iDcah:itioii,
and mounted the proceu aucceufuUy upon the cam mercial' scale. So far back a*
1777 be commnnicated to the Academy of Sciences ao iDtcresling hct, ithich he had
noticed, npoQ the mechaniBin employed by cbicka to break their ihells ; and for uune
time prior to the French reTolulion he furnished the Pariiiaii market with eieellcot
poultry atB period oF the year nhen the farmers had ceaied to mpplj it. His estab-
lithment was ruinedat that disastrous era, and no other has ever licctrbeen coostmned
or conducted with similar care. His apparatus derives peculiar interest from the (art
that it vas founded upon the principle of the circolaliou af hot water, by the iDtcstine
motions of ila particles, in a relumiag series of connected pipes ; a snbjcct aftervards
illuitraled in the eiperimenta! researcbea of Coant Rumford. It has of laie year*
been introdnced a« a nocdiy into Ihig country, and applied to warm the apanmenti of
many pnblic and private buildings. The following details will prove that the theory
and practice of hot water circulation were as perfectly understood by H. Bunnemaia
fifty years ago, as they are at the present day. They were then pnbliSly exhibited at
bit residence in Paris, and were afterwards commaaicated to tlie world at large in ihe
interesting article of the Encyclopidit Ttchndogiquc, intitled iKcvhatiem ArlifieieOe,
under the head of Hfgulatiur de Ttrnpiiaturt.
The apparatus of M. Bonnemain consisted: I, of aboller and pipes for the circo-
Ulion of water ; !, of a regulator calculated lo maintain an equable temperatarr ; 3.
of a stove -apartmeot, heated constantly to the degree best filled fur incabaiion. irbich
he called the liatching pilch. He attached to one side a pounaiiiTt or chick -room, fur
chiriahicg the chickeng during a few days aller incubation.
The biiller is represented In vertical section and ground plan, in/ijw, 987 and 9BS.
It is composed of a double cylinder of copper or cast iron I, i, having a grate b (see
.^ aa? _ P^'")- *" ■■'>P'' ^' '' (seclion). The water occupies the
shaded space C, C. h, g, p, e, t, are Eve vertical fluea for
* Gonduclingthe burnt air and smoke, which firat rise ii the
two exterior flues e, r, then descend in the two adjoiniog
flues r;, g, and finally remount through the passages i, i, in
the central flue h. During this upwards and dawnwarda
eircnIatioD, as shown by the arrows in the section, the
products of corabnslion are made to impart nearly tbe
whole of their heat to the water by which they are snr-
rounded. At the commencement, some bnming paper or
wood shavings are inserted at the orifice n, to establish a
draught in this circuitous chimney. The air is admilti'd
into the ashpit at the side, in regulated quantities, through
a small square door, movable round a rod which not
horizontally along iU middle line. This awing valve ii
acled upon by an eipanding bar (see HEAT.REGCLaToBt,
which opens it more or less, according to the temperature
of tbe stove aptulment b which the eggs are placed,
Dia the upper orifice ofthe boiler, by which the hotter «ad consequently lifter par-
ticles of the water continually ascend, and are replaced by the cooled panicles, which
enter the boiler near ila bollom, as shown ia^g. 989 at a. lutofurther details relative
to the boiler it Is needless to enter; for though its form, as designed by M. Bonnemain,
is eicelleutand most economical of heat for ■ charcoal fire, it would not snit ooeofpii'
coal, on accoant of the obslmction to the pipes which would soon be caused by its aom,
In_fig. 989 the boiler is shown at r, with the rod which regnlatea the air door of the
ashpit. D is a stopcock for modifying the opening by which the holler particles of
water ascend ; a a the waler pipe of ccmmimicalion, having the heating pipe of dis-
tribntioQ attached between e r, which thence passes backwards and forwards with a
very slight slope from the horiiontal direction, till it reaches the pousiiiiiin u p « It
traverses this apartment, and returns by N N to the orifice of the boiler a, where it torns
vertically downwards, and descends to nearly the bottom of the boiler, discbargiag at
that point the cooled and therefore denser particles of water to replace those which
etatinually issue upwards at d. l b is a tube surmonnled with « luDDel (br keeping
the range of pipes always full of water i and k is a siphon orifice for pennilliDg the
escape at the disengaged air, which would otherwise be apt to occapy partially the
pipes and obstracc the aqueous cirenlation.
INCUBATION.
(he boilvr, which Is ibe sole cause of its moTcmeat, will be greater, ir repretenU
Email lADcera filled with water, to supply the reqnisite moiitnre'lo the heated Btr, aad
to place the eggs, arranged along the trajB M M, in an atmosphere analogous to that
under the body of the ben-
Wlen we wish to hatch eggs with this apparatus, the fire is to be kindled iti the
boiler, and as soon as the teniperalure has ri^en to abont 100" F., the eggs are iotro-
duced ; but only ODe-twenlietb of the whole number intended, upon the first dayi next
da; a like number is laid npon the trays, and thae in succeaaion for twenty days, so that
opoD the twcDty-first day Uie eggs first plseed ma; be hatched for the most pan, and
we may obtaio daily afterwards an eqoal namber of cbicks. In this way regolarityof
care is established in the rearing of them.
Duriag the first days of ine nation, natnral as well as artificial, a small portion of the
water eoDtaioed in the egg eraporatea bjthe heat, tbroogh the ihelliaiid is replaced by
a like noantily of air, which is afterwards useful for the respiration of the animal. If
the warm atmosphere surrounding the eggs were very dry, such a portion of the aqueous
part of the eggs would eTaporalethroogh the pores of the shells as would endanger the
future life of the chick in obo. The transpiration trom the body of the hen, as she sits
opon her eggs, coonteraels this desiccation in general ; yet in Tcry dry weather many
batching eggs fbil from that caose, unless (hey be placed in moist decompoaiog straw.
The water saacers h n are therefore essential to success is artificial incubation.
After the chickens are hatched they are transferred into the nursery, o Q. on (he front
side of which there is a small grated trough fiUed with millet seed. Small divisioDS are
made between the broods of soccessiTC days, (o enable the superijitendent to vary their
feeding to tbeir age.
In order to supply an establishment of the common kind, where 100 eggs are to b«
hatched daily, a dozen of hens wonld be needed, and 1 60 eggs must be placed under
tbem, as only two-thirds in ^neral SDCceed. At this rale, 4300 mothers would be
required to sit. Now supposing we should collect ten times as man; hens, or 43,000,
we should not be able to command the above nnmber of chickens, as there is seldom a
tenth part of hens in a brooding state. Besides, there would be in this case no fewer
than T;jO hens eTery day coming out with a ft^sh brood of chickens, which would
require a regimeol of superintendents.
Artificial Incubation by meant qf Hot ifineral Watm. — This Curions process it
described very briefly in a letter by M. D'ArceL The following are extracts from bis
" Id June, I8S5, I obtained chickens and pigeons at Vichy, by artificial incubation,
effected tbroDgh the loeans of the thermal waters of that place. In 1 BS7 1 went to the
baths of Chandes-Aigues, principally for the purpose of doing the same thing there-
Finding the proprietor a zealous man, I succeeded in making a useful application of
this source of heat to the produclioQ of poultry.
" The sdTantage of this process may be comprehended, when it is known that the
invalids who arrive at Vichy, for instance in (he month of May, find chickens only the
size of quails ; whereas, by this means, they may be readily sapplied six months old.
" The good which may be done by establishing artificial incubation in places where
hot springs exist, is incaiulabU ; it may be introduced into these establishments wllbont
at all interfering with the medical treatment of patients, since the hatching would go
on in winter, u a time when the baths for other purposes are out of use.
Vol. II. K K
498 INDIGO.
" There is no other trouble required in breeding chickens, by meaxu of hot bsAi*
than to break the eggs at the proper time ; for, when the apartments are closed, the
lehole of the interior will readUy acquire a sufficiently elevated and rer j constant tem-
perature."
INCOMBUSTIBLE CLOTH is a tissue of the fibrous mineral called amisLnthiu
or asbestos. This is too rare to form the object of any considerable manalactiire.
Cotton and linen cloth may be best rendered incapable of burning with flame by being
imbued with a solution of sal ammoniac or of alunL
INDIAN INK, or CHINA INK. A very beautiful bhiok pigment, the best Tariedes
of which are obtained from China. Many absurd stories have been told about Indian
ink. It is composed of a very fine black, cemented together with some kind of animal
gelatine. It has been thought by Prechol to be a black obtained from camphor, which
is not improbable. See Ink.
INDIAN MATTING. Mats made in India from the long grass or reed Papyrut
corymbosus,
Indian rubber. See Caoutchouc.
INDIAN YELLOW. This is a peculiar precipitate obtmned from the urine of the
cow, and, according to some authorities, of the camel, after the animal has been eating
decayed and yellow mango leaves — the Mangistana mangifer. It appears to be com-
posed of magnesia with a yellow body which may be prepared pure by boiling the
mass with water, to which small quantities of muriatic acid are added, until the whole
dissolres, and then filtering. On cooling, the liquor deposits the colouring matter in
brilliant yellow scales, which are termed purreic acid {Kane), See Ures C^amieal
Dictionary for this acid and its deriyatives.
INDIGO. This invaluable dye-stuff consists essentially of a blue colouring matter,
to which the name of Indigo-Uue has been applied. This colouring matter occurs in
the leaves of several species of plants, which, though few in number, belong to vay
different genera and orders. The onl^ native European plant which is known with
certainty to yield it is the I%atis tinctoria, or common woad. It has also been supposed
to occur in the following plants, all of which are natives of Europe, viz.: — Asiragdba
glycyphyUus, Centaurea CyanuSy Chelidoniummajus, Cicer arietinunL, Colutea arbordcru,
CoroniUa EmeruSf Galega officinalis, Hedysarum OnobrychiSf Inula HdeniuaHj Iris Ger^
manica, Lotus comiculatus, Medicago sativa, Mercurialis perennis. Polygonum aviculare.
Polygonum Fagopyrum, Rhinanthus Crista-gaJlij Sambucus uigra^ Sambucus Ebubu^
Scaoiosasuccisa And Vaccinium Myrlillus. According to the investigations of Giobert and
others, however, none of these plants afford any indigo-blue, though several of them,
such as the Mercurialis perennis, contain a blue colouring matter of a peculiar nature.
The indigo-bearing plants growing in tropical countries furnish far more indigo-blue
than the Isatis tinctoria. Such are the various species of Indigo/era, natives of the
Etist and West Indies, the Nerium tinctorium and Calanthe ueratri/olia of Hindostan,
the Asclepias tinctoria and Marsdenia tinctoria of Sumatra, the Polygonum tincioriumj
the Isatis indigotica, the Justicia tinctoria, and the Blelia TankerviUia, of CSiina, and the
Amorpha fruticosa of Carolina. Most of these plants belong to the natural order
Leguminose. The others belong respectively to the orders Crucifenc, Apocynes,
Asclepiades, Polygoneas, Acanthacese, and Orchides. Indigo-blue has sometimes
been observed to form in the milk of cows, especially such as have been fed exclu-
sively on saint- foin. It has also been found by Prout, Hassall, and others in the
urine of individuals suffering fVom various diseases, and Schunck has lately shown
that the urine of men and animals, even when in a perfectly healthy state, may be
made to yield indigo-blue in small quantities by treatment with strong acids. Hence
it appears that this colouring matter may be obtained from a variety of sources, though
it is nowhere found in great abundance.
The use of woad for the purpose of dyeing blue seems to have been known in
Europe from the earliest times. We are told by Cesar that the Britons stained their
bodies blue with woad, in order to give themselves a more formidable appearance in
battle; and Pliny informs us that their women, before entering on certain sacred rites,
which were performed in a state of nudity, employed the same means of colouring their
bodies, whereby they acquired the appearance of negroes. During the middle ages
the cultivation of woad was carried on very extensively in several countries of Europe,
especially in Thuringia in Germany, in the province of Languedoc in France, and in
the neighbourhood of Rieti in Italy. The leaves of the plant were ground into a
pulp, and then submitted to a long process of fermentation, by which means they
were converted into a mass of a dark colour which was moulded into balls for the
use of the dyer. fSee Woad.) No attempt to extract the blue colouring matter
from the plant seems, however, to have been made before the commencement of the
present century.
Whether indigo in its present form was known to the ancients has been doubted.
INDIGO. 499
Pliny and Dioficorides refer to a pigment called Indicvm^ -which seems to have been of
a bine colour, though there is little doubt that the article to which the name Indicum
nigrum was applied was identical with our Indian ink. Of indicum Pliny says that
it comes from India and is obtained from the slime adhering to reeds; that it is black
when rubbed, but of a fine mixture of purple and blue when dissolved ; and that
there is another kind which is found swmiming on the dye-vessels where purple is
dyed, this being the scum of the purple-fish. He adds that those who adulterate
Sndicum dye pigeon's dung or chalk with woad, but that the genuine substance may
be known by heating it, when it g^ves a beautiful purple vapour and emits a smell
like that of the sea, and for this reason it has been supposed to be obtained from the
rocks. It cad hardly be doubted that in this passage indigo Is referred to, and that
the second kind of indicum mentioned by Pliny consisted probably of the scum of
indigo-blue found floating on the surface of the liquor in which the dyeing was per-
formed. It seems, however, that at that time the colouring matter was not so com-
pletely separated from the other vegetable matters of the plant as at the present
day, since pigeon's dung coloured with woad would bear very little resemblance to
our present indigo, but would be a fair imitation of the preparation usually made
from woad. It is probable, therefore, that at that period the process of manufacturing
indigo was a very rude one, and consisted merely in the separation of a portion of
the vegetable from the remainder. Even at the present day the natives of some
countries, where the arts have not attained any high degree of development, produce
an article from indigo-bearing plants which serves the purpose of dyeing blue, though
not much resembling indigo in appearance. In Sumatra, for instance, as Marsden
informs us, the natives do not manufacture indigo into a solid substance, but leave the
stalks and branches for some days in water to soak and macerate, then boil it, and
work with their hands some chunam (quicklime) among it, with leaves of the pcuxio
aaha (a species of fern) for fixing the colour, after which they drain it off and use it
in the li(^uid state. On the west coast of Africa the leaves of the indigo plant are
moulded mto balls, which are then dried in the sun and stored op until they are
wanted. These balls, which have a slight blue tint, may be preserved a long time
and be transported to great distances. When they are to be used for dyeing they are
broken and reduced to a fine powder. This powder is then mixed with water to which
the ashes of a certain plant are added, and the liquid is boiled in large earthenware
vessels of a conical form, when it assumes a deep blue colour and is then ready for
dyeing the fabrics which are plunged into it.
The article known as indigo in the middle ages must have been very similar to the
indigo of the present day ; for though Marco Polo had described the manner in which
the substance was produced from the plant, it was for a long time considered as a
mineral ; and even in the letters patent obtained in 1705 by £he proprietors of mines
in the principality of Halberstadt, it was classed among minerals on account of which
works were suffered to be erected.
Indigo seems to have been first extensively used in Europe by the Jewish dyers,
who introduced it into the d^e-houses of Italy. It was not, however, imported in any
large quantities until the discovery of the passage round the Cape of Good Hope.
At the beginning of the 17th century, the Dutch commenced carrying on an exten-
sive trade with the East, and indigo was one of the articles which they imported in large
quantities into European countries. Its use was'found to be attended with so many
advantages, that the employment of woad for the same purpose was gradually aban-
doned. The colour produced by it was more brilliant and far cheaper than the blue
from woad. On the other hand it was asserted that the goods dyed with indigo faded
rapidly, and that the vitriol and other corrosive substances used along with it caused
them, after some time, to rot. At the same time the exportation of large sums of
money in payment for indigo, and the rapid decline in the cultivation of woad, which
had previously furnished occupation to great numbers of people in various countries of
Europe, and had been the source of great wealth to individuals, caused so much alarm,
that the most stringent measures were adopted in order to prevent the use of indigo
in dyeing. A decree of the Germanic diet held at Frankfort, in 1577, prohibited,
under the severest penalties, the newly invented, pernicious, deceitful, eating and
corrosive dye, called the devi» dpe, for which vitriol and other cheaper materials were
used instead of woad. This prohibition was renewed in 1594 and 1603. In the year
1650, the Elector of Saxony prohibited the sale and importation into his dominions of
all &bric8 dyed with other materials in the place of woad. This was followed by an
imperial nmndate issued from Batisbon, in the year 1654, forbidding the importation
and the use by dyers of indigo and other injurious substances, and threatening with
punishment and the confiscation of their goods all persons who should offer for sale any
cloth dyed with forbidden and deceitful dyes instead of with the pennanent colour of
woad. The people of Nuremberg even went so far as to compel their dyers by law
KK 2
500 INDIGO.
aonnally to take oatb, not to employ indigo, and this was continned down to a Terj
recent period, diough it was well known that its use was indispensable to them. In
France, the use of indigo was forbidden in 1598, in consequence of an argent represen-
tation by the states of the province of Languedoc, and this prohibition was aft^-wards
repeated several times. But in the well-known edict of 1669, in which Colbert sepa-
rated the fine from the common dyers, it wss stated that indigo should be used with*
out woad ; and in 1737, dyers were left at liberty to use indigo alone, or to employ a
mixture of indigo and woad. In England the use of indigo was also forbidden, flmd
by an act passed in the reign of Elizabeth, searchers were authorised to bam boch U
and logwood in every dye-house where they could be found. This act remained in
force for nearly a century.
It has been doubted whether the plant which is employed in America ibr the
manufacture of indigo is a native of that continent, or whether it was introduced by
the Spaniards. It was remarked by the first voyagers on the new continent that the
natives coloured their bodies and dyed their staffs by means of indigenous plants
which resembled the indigo plant of Asia. Fernando Columbus, in the life of his
father, says, that this plant grew in a wild state in the West India Islands, and that it was
cultivated for the purpose of obtaining fW)m it a blue pigment Hemandes mentions
it among the native plants of Mexico, and says, that the Americans used it for dyeing
their hair black. He adds, that they made from it a pigment, which they named
mohuidi and tleuohuiUi, the same as the ctaruleum of the Latins, and he describes alio
the method of preparing it Nevertheless it appears that the Indigo/era Unetoria and
Anil 'were really introduced into America by the Spaniards, and were the plants em-
ployed by them for the manufacture of indigo in Mexico, Guatemala, and St Domingo^
though some of the varieties produced by the influence of the climate and soil differ very
widely in appearance from the parent stock. The manufacture of indigo was at one
time carried on extensively in Central America and the West India Islands, and these
couDtries formerly supplied the chief portion of the article consumed in Europe. Tlie
indigo of Guatemala at the same time surpassed all others in quality. In consequence
however, of the political disturbances in America, and the great improvements which
have been effected in the manufacture of indigo by the zeal and perseverance of oar
countrymen in the East, its production in America has diminished very much, and at
the present day, the indigo consumed in Europe is derived chiefly from India, and more
especially from Ben^, Oude, and Madras. The remainder is imported from Java,
Manilla, the Mauritius, and Senegal in the eastern hemisphere, and from Caraecas,
Brazil, and Gautemala in the western. The East Indian and Brazilian indigo comes
packed in chests, the Guatemala in ox-hides, called serons. Its quality depends upon
the species of the plant, its ripeness, the soil and climate of its growth, and Che mode
of manufactare.
The plants which are cultivated in the East Indies, are the Indigo/era thietoria,
Anilf disperma and puudo'tinctoria. The districts of Kishenagar, Jessore, and Moor-
shedabad, in Bengal, ranging from 88^ to 90^ east lat and 22}^ to 24^ north lon^,
produce the finest indigo. That f^om the districts about Burdwan and Benares is of
a coarser or harsher grain. Tyroot, in lat 26°, yields a tolerably good article. The
portion of Bengal most propitious to the cultivation of indigo, lies between the river
Hoogly and the main stream of the Ganges. The ground having been ploughed in
October, November, or beginning of December, the seed of the indigo plant is sown
in the last half of Biarch or beginning of April, while the soil being neither too hot
nor too dry, is most propitious to its germination. A light mould answers best ; and
sunshine, with occasional light showers, are most favourable to its growth. From
twenty-fonr to thirty pounds of seeds are required for sowing an acre of land. The
plants grow rapidly, and will bear to be cut for the first time at the beginning of July,
nay, in some districts, so early as the middle of June. The indications of maturity
are the bursting forth of the nower buds, and the expansion of the blossoms ; at which
period the plant contains most colouring matter. Another indication is taken from
the leaves ; which, if they break across, when doubled fiat, denote a state of maturity.
But this character is somewhat fallacious, and depends upon the poverty or richness
of the soil. When much rain falls, the plants grow too rapidly, and do not sufficiently
elaborate the blue pigment Bright sunshine is most advantageous to its productioo.
The first cropping of the plants is best ; after two months a second is made ; but at
the present day, planters never undertake a third or fourth.
Two methods are pursued to extract the indigo firom the plant ; the first effects it
by fermentation of the fresh leaves and stems ; the second, by maceration of the dried
leaves.
1. From the recent leaves, >— In the indigo factories of Bengal, there are two large
stone-built cisterns, the bottom of the first being nearly upon a level with the top of
the second, in order to allow the liquid contents to be run out of the one into the other.
INDIGO. 501
The uppermost is called the fermentiDg Tat, or the steeper ; its area is 20 feet sqdare,
and its depth 3 feet ; the lowermost, called the beater or beating yat, is as broad as the
other, bat one third longer. The cattings of the pl&nt, as they come from the field,
are stratified in the steeper, nntil this is filled to within 5 or 6 inches ft'om its brim. In
order that the plant, dunng its fermentation, may not swell and rise out of the vat, beams
of woodlmd twigs of bamboo are braced tightly over the sarfieuse of the plants, after
which water is pumped upon them until it stands about 3 or 4 inches from the
edge of the yessel. An active fermentation speedily commences, which is completed
within 14 or 15 hours, a tittle longer or shorter, aecording to the temperature of the
air, the preyailing winds, the quality of the water, and the ripeness of the plants.
Nine or ten hours after the immersion of the plant, the condition of the vat must be
examined ; frothy babbles are then seen rising like little pyramids, at first of a white
colour, but soon becoming greyish-blue, and then deep purplish-red. The fermenta-
tion is at this time violent, the fluid being in constant commotion, and apparently
boiling, innumerable bubbles mount to the surface, and a dense copper-coloured scum
covers the whole. As long as the liquor is agitated, the fermentation must not be
disturbed ; but when it becomes more tranquil, the liquor is to be drawn off into the
lower cistern. It it of the utmost consequence not to push the fermentation too far,
because the quality of the whole indigo is thereby deteriorated ; but rather to cat it
short, in which case there is, indeed, a loss of weight, but the article is better. The
liquor possesses now a glistening yellow colour, nrhich, when the indigo precipitates
changes to green. The average temperature of the liquor is commoiSy 85^ Fahr. ;
its specific gravity at the surface is 1 '0015 ; and at the bottom 1 '003.
As soon as the liquor has been run into the lower cistern, ten men are set to work
to beat it with oars or shovels 4 feet long, called biuqueU, Paddle wheels have also
been employed for the same purpose. Meanwhile two other labourers clear away
the compressing beams and bamboos f)rom the surface of the upper vat, remove the
exhausted plant, set it to dry for fad, clean out the vessel, and stratify firesh phmts in
it. The fermented plant appears still green, but it has lost three fourths of its bulk
in the process, or from 12 to 14 per cent, of its weight, chiefly water and extractive
matter.
The liquor in the lower vat must be strongly beaten Ibr an hour and a half, when
the indi^ begins to agglomerate in flocks, and to precipitate. This is the moment
for judgmg whether any error has been committed in the fermentation ; which most
be corrected by the operation of beating. If the fermentation has been arrested too
soon, much f^th rises in the beating, which must be allayed with a little oil, and then
a reddish tinge appears. If large round granulations are formed, the beating is con-
tinued, in order to see if they will grow smaller. If they become as small as Sne sand,
and if the water clears up, the indigo is allowed qulietly to subside. Should Uie vat
have been over fermented, a thick fat-looking crust covers the liquor, which does not
disappear by the introdaction of a flask of oil. In such a case the beating must be
moderated, and when the granulations become round, and begin to subside, and the
liquor clears up, the beating must be discontinued. When the fermentation has been
excessive, the froth or scum diffuses itself spontaneously into separate minute particles,
that move about the surface of the liquor. On the other hand, a rightly fermented
vat is easy to work ; the froth, though abundant, vanishing whenever the granulations
make their appearance. The colour of the liquor, when drawn out of the steeper into
the beater, is bright green ; bat as soon as the agglomeration of the indigo commences,
it assumes the colour of Madeira wine ; and speedily afterwards, in the course of
beating, a small round grain is formed, which &Us down and leaves the water trans-
parent, when all the turbidity and firoth vanish.
The object of the beating is threefold : first, it tends to disengage a great quantity
of carbonic acid present in the fermented liquor ; secondly, to give 9ie newly de-
veloped indigo its requisite dose of oxygen by the most extensive exposure of its
particles to the atmosphere ; thirdly, to agglomerate the indigo in distinct flocks or
granulations. In order to hasten Uie precipitation, lime water is occasionally added
to the fermented liqaor in the progress of beating ; but those who manufacture the
superior qualities of indigo, avoid the use of lime, as it has a tendency to make the
indigo hard and red. In one side of the beating vessel a beam is fixed upright, in
which three or more holes are pierced a few inches in diameter. These are closed
with plugs during the beating, but, two or three hours afterwards, as the indigo
subsides, the upper plug is withdrawn to run off the supernatant liquor, and then the
lower plugs in suecession. The state of this liqaor affords, on being examined, an
indication of the success of both the processes. When the whole Hquor has run
off, a labourer enters the vat, sweeps all the precipitate into one- comer, and empties
the thinner part into a spout which leads into a cistern. 20 feet long, 3 feet wide and
3 feet deep. When all this liquor is once collected, it is pumped through a bag
KK 3
502 INDIGO.
-which retains the imparities into a boiler, placed at the side of the cistern and heated
to ebullition. The ^th soon subsides, leaving an oily looking film npon the liquor.
The indigo is by this process not only freed from the yellow extractive matter, but
its density and the intensity of its colour are increased. From the boiler the mixture
is run, after two or three hours into a general receiver, called the dripping vat or tables
which, for a factory of twelve pairs of preparation vats, is 20 feet long, 10 ftet wide,
and 3 feet deep having a false bottom, 2 feet under the top edge. The cistern
stands in a basin of masonry (made water-tight with Chunam hydraulic cement), the
bottom of which slopes to one end, in order to facilitate the drainage. A thick
woollen web is stretched along the bottom, of the inner vessel to act as a filter ; bat
a piece of cotton cloth is generally preferred to wool, as the h^rs which are detached
ftovx the latter injure the quality of the indigo. As long as the liquor passes through
turbid, it is pump^ back into the receiver. Whenever it runs clear, the receiver is co>
vered with another piece of cloth to exclude the dust, and allowed to drain at its leisore.
Next rooming the drained magma is put into a strong bag and squeezed in a press. The
indigo is then carefully taken out of the bag, and cut with brass wire into cnbical pieces,
measuring about 3 inches each way, which are dried in an airy house upon shelves
of wicker work. Daring the drying, a whitish efflorescence appears npon the pieces,
which must be carefully removed with a brush. In some places, particnlarlj on
the coast of Coromandel, the dried indigo lumps are allowed to effloresce in a cask
for some time, and when they become hard they are wiped and packed for exporta-
tion.
From some experiments it would appear that the gas disengaged daring the middle
period of the fermentation is composed in 100 parts of 27*5 cart>onic acid, 5-8 oxygen,
and 667 nitrogen ; and towards its conclusion, of 40*5 carbonic acid 4*5 oxygen, and
55*0 nitrogen. Carburetted hydrogen does not seem to be disengaged. That the
liquor in the beating vat absorbs oxygen from the air in proportion as the indigo
becomes flocculent and granular, has been ascertained by experiment, as well as that
sunshine accelerates the separation of the indigo-blue. Out of 1000 parts of the
fermented liquor of specific gravity r003, the blue precipitate may constitute 0*75
of a part. Such a proportion upon the great scale, is however, above the average,
which is not more than 0'5. When lime water is added, an extractive matter is
thrown down, which amounts to from 20 to 47 parts in 1000 of the liquor. It has a
dark brown tint, a viscid appearance, an unpleasant smell, and a bitter taste. It
becomes moist in damp air, and dissolves in water without decomposition. It ii
precipitated by lime, alkalies, infusion of galls, and acetate of lead. All indiflo con-
tains a little lime derived from the plants even though none has been used in its pre-
paration.
2. Indigo from dried leaves, — The ripe plant being cropped, is to be dried in sunshine
from 9 o'clock in the morning till 4 in the afternoon, during two days, and threshed
to separate the stems from the leaves, which are then stored up in magazines antil a
sufficient quantity is collected for mauafacturiog operations. The newly dried leaves
must be ft^e from spots, and friable between the fingers. When kept dry, the leaves
undergo in the course of four weeks, a material change, their beautiful green tint
turning into a pale bluish-grey, previous to which the leaves afford no indigo by
maceration in water, but subsequently a large quantity. Afterwards the product
becomes less considerable.
According to some manufacturers, the plants should be cut down in dry weather,
an hour or two before sunset, carried off the field in bundles, and immediately spread
upon a dry floor. Next morning the reaping is resumed for an hour and a half,
before the sun acts too powerfully upon vegetation, and the plants are treated in
the same wa^. Both cuttings become sufficiently dry by 3 o'clock in the afternoon,
so as to permit the leaves to be separated from the stems by threshing. They are
now throughly dried in the sunshine, then coarsely bruised, or sometimes ground to
powder in a mill, and packed up for the operations of manufacture.
The following process is pursued to extract indigo fh>m the dried leaves. They
are infused in the steeping vat with six times their bulk of water, and allowed to
macerate for two hours with continual stirring till all the floating leaves sink. The
fine green liquor is then drawn of into the beating vat, for if it stood longer in the
steeper, some of the indigo would settle among the leaves and be lost. Hot water,
as employed by some manufacturers, is not necessary. The process with dry leaves
possesses this advantage, that a provision of the plant may be made at the most
suitable times, independently of the vicissitudes of the weather, and the indigo
may be uniformly made ; and moreover, the fermentation of the firesh leaves, often
capricious in its course, is superseded by a much shorter period of simple macera-
tion.
We are indebted to Dr. Roxburgh, for a description of the method employed for
INDIGO. 603
manoikctarmg indi^ from the Ntrivm tinctoriymor Wrightia tinctoria. (Vide Tran-
sactions of the Society of Arts, toL zxtUl) This plant, which attains the size of a
small tree, is fonnd on the lower regions of the mouitainoos tract near Rnjamundry,
and also on hills in the neighbonrhood of Salem and Pondicherry, and grows in a
sterile as well as rich soil. The leayes begin to appear in March and April, and
at the end of April have attained their full size, when they are ready for gathering.
At the end of Angast they be^ to assnme a yellowish msty colour and soon fall
off. The leaves yield no indigo until the plant is seyeral years old, but tiie best
leaves for making indigo are obtained from low bushy plants. They improve when
kept for a day or two, but when they begin to wither, they yield but a small portion
of very bad indigo, and when quite dry only a dirty brown fecula. In this they
diifer from the leaves of the common indigo plant, which may be dried before ex-
traction without loss of colour. They also differ from the latter in not yielding their
eolonr to cold water. With cold water only a hard, black, flinty substance is ob-
tained, not blue indiga It is therefore necessary to employ hot water, which ex-
tracts the colour very readily. The leaves having been collected, are on the ensuing
day thrown into copper scalding vessels, which are then filled wiUi cold water to
within 2 or a inches of the top. Hard water containing a large quantity of bicarbonate
of lime is better adapted for the purpose than rain water. The fire is then lighted
and maintained rather briskly until Uie liquor acquires a deep green colour. The
leaves then begin to assume a yellowish colour, the heat of the liquor being about
150^ to 160^ Fahr. The fire is then removed and the liquor run off into the beating
vat Here it is agitated from 5 to 20 minutes. It is then mixed with about ffg to ^th
part of lime water, which produces a speedy granulation. After the indigo has subsided
the supernatant liquid appears of a clear Madeira wine colour. The quantity of indigo
obtained, amounts to 1 lb. frt>m 250 lbs. of green leaves ; but it varies according to the
season and the state of the weather. In August and September, the produce is only
one-half or two-thirds of what it is in May and June, and even that is diminished if
the weather is wet, or the leaves are treated immediately after being gathered. The
acaldingrequires about three hours, and the agitation and precipitation the same
time. The indigo is improved by treating it wi^ a little sulphuric acid. The only
ftult it has is, that it breaks into small pieces, unless it has been dried slowly in the
shade protected from the sun.
In the southern provinces of China a species of Indigofera is extensively culti-
vated for the sake of the dye which it affords. In the nordiem provinces two other
plants are employed by the inhabitants for the same purpose. Mr. Fortune, the
weU -known Chinese traveller, to whom we owe the description of these plants
and of the process of manufacturing indigo from them, states that one of them is
grown in the neighbourhood of Shanghae, and he has given it the name of Isatia
mdigotica. The other, which is a species of Juaticia, is largely cultivated in the
hiUj coun^ near Ningpo, or rather in the valleys among the hUls. It seems to be
easily cultivated; it grows most luxuriantiy, and is no doubt very productive.
Having evidently been introduced from a more southern latitude, it is not hardy in
the province of Chekiang any more than cotton is about Shanghae ; but nevertheless
it succeeds admirably as a summer crop*. It is planted at the end of April or beginning
of May, alter the spring frosts are over, and it is cleared from the ground in
October. During this period it attains a height of a foot or a foot and a half, becomes
very bushy, and is densely eovered with large green leaves. It is cut before any
flowers are formed. The plants are grown, not from seed but from cuttings. These
cuttings consist simply of a portion of the stems of the previous year, which after
being stripped of tiieir leaves are tied into bundles, each containing upwards of
1000, and kept during the winter in a dry shed or outhouse, where after being firmly
packed together they are bemked round with dry loam, and covered with straw or
litter so as to protect them fh>m the frost During the winter months the cuttings
remain green and plump, and although no leaves are produced a few roots are
generally fonnd to be formed or in the act of forming when the winter has passed
and the season for planting has come round. In this state they are taken to the fields
and planted. The weather during the planting season is generally showery, as this
happens about the change of the monsoon when the air is charged with moisture. A
few days of tiiis warm showery weather is sufficient to establish the new crop, which
now goes on growing with luxuriance and requires little attention during the summer,
indeed none except keeping the land f^ from weeds. In the countrv where this dye
is manuikctured there are numerous pits or tanks on the edges of the fields. They are
usually circular in form and have a diameter of about 11 feet and a depth of 2 feet
About 400 catties * of stems and leaves are thrown into a tank of this sixe, which is
* A Cbineie catty It equal to l|Ib.
KK4
504 INDIGO.
then filled to the hrim with clear yaJter, In fi^e days the plant is partially decom-
posed, and the water has become yellowish-green in colour. At this period the
whole of the stems and leaves are removed from the tank with a flatheaded broom
made of bamboo twigs. When every particle has been removed, the workmen em-
ployed give the water a circular and rapid motion with the brooms just noticed, which
IS continued for some time. During this part of the operation another man has
employed himself in mixing about thirty catties of lime with water, which water has
been taken out of the tank for the purpose. This is now thrown into the tank, and
the rapid circular motion of the water is kept up for a few minutes longer. When
the lime and water have been well mixed in this way the circular motion is allowed to
cease. Four men now station themselves ronnd the tank and commence beating the
water with bamboo rakes made for this purpose. The beating process is a very
gentle one. As it goes on, the water gradually changes from a greenish hue to a
dingy yellow, while the froth becomes of a beautiful bright blue. During the process
the head workman takes a pailful of the liquid out of the tank and beats it rapidly
with his hand. Under this operation it changes colour at once, and its value is
judged of by the hue it presents. The beating process generally lasts for about
half an hour. At the end of this time the whole of the surface of the liquid is
covered with a thick coating of froth of the most brilliant colours, in which blue
predominates, especially near the edges. At this stage, it being desirable to incor-
porate the froth with the liquid below it, it is only necessary to throw a small quantity
of cabbage oil on the surface of the froth. The workmen then stir and beat it
gently with their flat brooms for a second or two, and the whole instantly disappears.
The liquid, which is now darker in colour, is allowed to repose for some hours,
until the colouring matter has sunk to the lower stratum, when about two thirds of
the liquid is drawn off and thrown away. The remaining third part is then drawn into
a small square tank on a lower level, which is thatched over with straw, and here it
remains for three or four days. By this time the colouring matter has separated
itself from the water, which is now entirely drained off, the dye occupying three or
four inches of the bottom in the form of a thick paste ajid of a beautiful blue ccdoor.
In this state it is packed in baskets and exposed for sale in all the country towns in
this part of China. liike the Shanghae indigo, made from Isatis indiffotica, it is
called '* Tien-ching** by the Chinese. — Crardner*s Chronicle and Agricultural GaseUe^
April 8th, 1854.
The cultivation of indigo in Central America, has ^dlen off very much of late yean.
Nicaragua formerly exported annually about 5000 bales of 150 lbs. each. At present
the export probably does not exceed 1000 or 2000 bales. Under the government of
Spain, the state of San Salvador produced from 8000 to 10,000 bales annually. A
piece of ground equal to two acres generally produces from 100 to 120 lbs. at a
cost of not far from 30 to 40 dollars.
There is an indigenous biennial plant abounding in many parts of central America,
which produces indigo of a very superior quality, but gives less than half the weight
which is afforded by the cultivated species. The Indigofera disperma is the species
employed in cultivation. It attains its highest perfection in the richest soils. It
will grow, however, upon almost any soil, and is very little affected by drought or
by superabundant rains. In planting it, the ground is perfectly cleared, usually
burnt over, and divided with an implement resembling a hoe into little trenches, 3
or 3 inches in depth, and 12 or 14 apart, at the bottom of which the seeds are strewn
by hand, and lightly covered with earth. A bushel of seed answers for 4 or 5 acres
of land. In Nicaragua it is usually planted towards the close of the dry season in
April or May, and attains its perfection for the purpose of manufacture in from two
and a half to three months. During this time it requires to be carefully weeded, to
prevent any mixture of herbs, which would injure the quality of the indigo. When
It becomes covered with a kind of greenish farina, it is in a fit state to be cut. This
is done with knives at a little distance above the root, so as to leave some of the
branches, caUed in the West Indies " ratoons," for a second growth, which is also in
readiness to be cut, in fttrai six to eight weeks after. The crop of the first year is
usually small, that of the second is esteemed the best, although that of the third is
hardly inferior. It is said that some fields have been gathered for ten consecutive
years without being re-sown, the fallen seed obviating the necessity of new pUnt'^^g?
After the plant is cut, it is bound in little bundles, carried to the vat, and placed in
hiyers in the upper or larger one called the steeper (mojadora). This vat holds from
1000 to 10,000 gallons, according to the requirements of the estate. Boards loaded
with weights are then placed upon the plants, and enough water let on to cover the
whole, which is now left to steep or ferment. The rapidity of this process depends
much upon the state of the weather and the condition of the plant Sometimes it is
accomplished in 6 or 8 hours, but generally requires from 1 5 to 20. The proper length
INDIGO. 505
of time U determined by the colour of the saturated water ; but the great secret is to
check the fermentation at the proper point, for upon this, in a great degree, depends
the quality of the product Without disturbing the plant, the water is now drawn off
bj cocks into the lower vat or ** beater ** (golpeadoro)^ where it is strongly and inces-
santly beaten, in the smaller estates with paddles by hand, in the larger by wheels
turned by horse or water power. This is continued until it changes from the green
colour, which it at first displays, to a blue, and until the colouring matter, or flocculfe,
shows a disposition to curdle or subside. This is sometimes hastened by the infusion
of certain herbs. It is then allowed to settle, and the water is carefully drawn off.
The pulp granulates, at which time it resembles a fine soft clay ; after which it is
put into bags to drain, and then spread on cloths in the sun to dry. When properly
dried, it is carefully selected according to its quality, and packed in hide cases, 150 lbs.
each, called serons. The quality has not less than 9 gradations, the best being of
the highest figure. From 6 to 9 are called Jlores, and are the best ; f^om 3 to 6
eortes : from 1 to 3, inclusive, cobres. The two poorer qualities do not pay expenses.
A mansana of 100 yards square produces on an average about one ceroon at each
cutting. After the plant has passed through the vat, it is required by law that it
shall be dried and burnt ; because in decomposing it generates by the million an
annoying insect called the *' indigo fly.''
The following account of the manufacture of indigo on the Senegal is taken from
Perottet's " Art de I'lndigotier " : —
The land destined to the cultivation of the plant ought to be perfectly level and
free from undulations, so as to prevent the seed from being washed into the hollows
or lower parts by the heavy rains so frequent in the tropics. Soils of a greyish colour
abounding in clay are not adapted for the purpose, as they are too compact and cold.
Sandy soils of a whitish colour must also be avoided. Light soils, abounding in
humus or vegetable remains, and having a colour between grey and dark brown,
are to be preferred to all others. The soil should, at all events, not be one very
retentive of moisture. The quantity of indigo obtained from the same weight of
plant may vary, according to the soil, from 4 lbs. to 10 lbs., and the quality also
varies in a corresponding degree. The extent of ground which is required for the
production of indigo on a large scale is so great that the use of manure becomes
almost impossible. Nevertheless the employment of the refuse of the p^^t, after the
extraction of the indigo, as a manure on ft'esh plantations, is found to be attended with
very beneficial results. The ground, if new, must be turned up by means of a plough
or hoe, to the depth of at least 10 or 12 inches, three times successively at intervals of
3 months, before the sowing takes place. The sowing must only be undertaken in
fine weather, never during heavy rain. The seed employed should be perfectly ripe,
and, if possible, not more than one year old. It is to be left in the seed,- vessels in
which it is contained until the time when it is wanted. The latter are then put into
a wooden mortar and reduced to firagments, and the seed is separated by winnowing
from the dust, debris, &c., with which it is mixed. The sowing is to be effected
broad- cast and as evenly as possible. It should take place, if possible, just before the
approach of rain, in which case the use of a harrow is not required, as the rain gene-
rally has the effect of completely levelling the ground and covering np the seed with
soiL The Indigofera tinctoria^ and its varieties macrocarpa and emarginata, being a
plant with numerous crowded branches, it is not necessary, in sowing it, to take more
than from 6 to 7^ kilogrs. of seed to 1 arpent of ground ; but the Indigo/era anil, being
more sparingly branched, and therefore taking up less room, requires to be more
thickly sown. At about ten or twelve days after sowing, when the young indigoferse
have attained a height of about 81 to 108 millimetres, the ground must be carefully
weeded, and this operation must be repeated as soon as the weeds have again made
their appearance and commenced to interfere with the growth of the crop. When tlie
season is £sivourable three months are generally sufficient to enable the plants to attain
the degree of development necessary for the production of indigo. At the period
when inflorescence commences the plant is far richer in colouring matter than at any
other. As soon, therefore, as there are any indications of flowering, and when the
lower leaves, in the axils of which the flowers appear, begin to acquire a yellowish
tint, and when pressed in the hands produce a slight crackling noise, no time must
be lost in cutting down the plant. This is effected by means of good knives or sickles,
and as near the ground as possible. The stems, after being cut, are tied together into
bandies or sheaves and carried to the manufactory. Since the colouring principle of
the indigofera) is extremely susceptible of change by the action of destructive agencies,
it is necessary to use the utmost despatch in gathering the crop, and to have the manu-
factory of such a size in proportion to the plantation, that no time may be lost in work-
ing up the material as soon as gathered. The plants must on no account be cut when
they are moistened either with rain or dew, because in this case they acquire a blackish
506 INDIGO.
tint in conMqnenoe of ihe friction to wluch thej are exposed in cutting tbem and
taking them to the manofactorj, this tint being a sign of the disappearance of the
colouring matter. Besides this, it has been observed ^t during the continuance of
run the indigo-producing principle diminishes yerj considerably, and sometimes
eren disappears entirely, so that, if cut during or immediately after rain, the plants
yield little or no indigo. The indigo plant is subject to the attack of a green cater-
pillar, which sometimes appears in such quantities as to destroy the whole crop. No
certain and easy means of destroying this pest is known. It has been recommended
to pass wooden rollers over the ground, before the plants have attained any great
size, so as to crush the caterpillars without iiguring the plants, and this plan has been
attended with partial success.
In order to obtain good results in the manu£icture of indigo, it i« necessary that
the plants should be of the same age, of the same species, and from the same field.
The Indigofara anil begins to ferment several hours sooner than the /. tinetoria^
so that if a mixture of both be taken, the produce from either one or the other -win be
lost, and the indigo obtained will also be of a bad qoality. The plants should, as
soon as possible after being gathered, be placed in the steeping vat, which u a vessel
built of bricks, and well lined with cement, from 3| to 8 metres in length, of the
same width, and about 1 metre deep. In this vessel the plants are arranged in suc-
cessive layers, the lower layers being slightly inclined towards one end, in order to
facilitate the subsequent running off of the liquor. The vessel being fiiU, a number
of poles of fir-wood are laid lengthways over the plants, at a distance of 162 milL
from one another. Three beams are then laid crosswise over the poles, their ends
being well secured by passing them through slits which are cut in the upright
posts at the sides of the cistern, and then fixing them by means of iron pins, p*f*mg
trough holes in Uie posts. By this means the plants are prevented from rising above
the surface of the liquor daring the process of maceration. The vat is now filled
with water from an adjacent cistern, in which it has been allowed to stand for 24
hours for the purpose of allowing all foreign matters contained in it to be depo-
sited. After standing in contact with the leaves for about 6 hours, a change usually
begins to manifest itself in the liquor, which most therefore, from that time forward,
be carefally watched. As soon as this liquor begins to acquire a green colour, and
when a little of it on being kept for a short time in the mouth, leaves a slight impres-
sion of harshness (dpreti) on the tongue and the palate, it is a sign that the macera-
tion is complete, and that the liquor should be drawn off without delay. If this be
not done, Uie colour of the liquor changes from green to brown, a new species of
fermentation commences, accompanied by the formation of acetic acid, and the
plant begins to yield substances of a mucilaginous nature, which contaminate the
indigo, and completely spoil its quality. It is therefore of the g^reatest importance
to ascertain exactly when the maceration of the plant is complete. The following
are the chief indications of this point having been attained : — 1. When the water
which was at first clear begins to become muddy and acquire a slight greenish tinge.
2. When babbles of a greenish colour rise to the sarface here and there. 3. When
towards the edge of the vat some mucilage, or a kind of greyish scum, commences to
be formed. 4. When a very slight purple pellicle is observed on the surfiice of the
liqaor, especially near the comers of the vat 5. When the liquor begins to exhale a
slight but not disagreeable odour of herbs. When the fermentation has proceeded
too far, the following phenomena present themselves : — 1. A considerable quantity oil
large bubbles of air are disengaged, which burst at the surface, forming a layer of
greyish mucilage. 2. The surface of the liquor becomes covered with a copper-
coloured pellicle. 3. A heaving of the liquor in the vat is observed, giving rise to
the disengagement of large greenish bubbles which communicate a brownish colour
to the water. 4. The liquor acquires a fetid smell, a strongly acid taste, and a soapy
appearance. These phenomena manifest themselves when the weather is hot, after
the fermentation has continued about 12 or 14 hours. It then becomes impossible to
obtain indigo of good quality, the only product being a black matter resembling wax.
The liqaor is now run off from the steeping vat into the beater, which is a cistern
of about the same dimensions as the former, but situated at a rather lower level. Here
it is subjected to the beating process, the object of which is to expose the reduced
indigo to the oxygen of the atmosphere, as well as to promote the disengagement of
the carbonic acid ^ with which the liquid is charged, and which prevents the pre-
cipitation of the indigo. The beating is perform^ by men, who, provided with
paddles, agitate the liquid rapidly, so as to bring every part of it successively into
contact with the air. It is of importance that this process should be broken off at the
right moment, for if it be continued too long, the grain formed at first will redissolve
and be lost And if, on the other hand, it be arrested before the proper time has
arrived, a portion of the indigo will remain unprecipitated. In order to ascertain in
INDIGO. 507
^bat state the liqnor is, a little of it mast be poured into a drinking glass and mixed
-with an eqnal Tolome of clear water. If there is formed roand the circamference of
the glass a line of a bloish-green coloar, the beating must be continued ; but if on the
contrary the liauid appears of a uniform brown colour, and if on adding to it a few
drops of clear bme water with the finger the indigo precipitates immediately in grains,
the process must be arrested. The beating usually occupies from an hour and a half
to two hours. The liquid is now to be well mixed with about i^h of its volume of
clear lime water, and allowed to rest until the indigo has quite settled. By opening
successively the plugs which are placed at different heights in the side of the vessel,
the clear liquor is then drawn off in separate portions and permitted to run away, care
being taken that none of the indigo is allowed to be carried away with the water.
By means of an opening situated near the bottom of the beating vat the indigo mixed
with water is then run off, and flowing through a canal is received on a cloth
strainer or filter. This filter rests on a round or four-cornered vessel, the top of
which is on a level with the surface of the ground, and which is called the diabhiin.
When the liquid has run through the filter, the indigo which remains behind in a state
of paste is mixed up a^in with water, and the mixture is poured on a canvas filter and
allowed to run immediately into the boiler. The refhse matter, consisting of leaves of
the plant, &c., remains on the canvas, while the indigo suspended in water runs through.
The boiler is a vessel with sides of masonry, and a bottom consisting of a copper pbte
which rests on iron bars, and is well cemented to the sides. Underneath the copper
plate is the fire-place. The top must be covered with a wooden lid, consisting of two
flaps which are fixed to hinges at the sides and meet together over the top. At the
moment when the mixture of indigo and water is introduced into the boiler, the latter
must already be about one third full of hot water, the mixture being suflScient almost
to fill it entirely. The heat is now raised gradually to the boiling point, and the
boiling is continued for about two hours. In order to prevent the mdigo from ad-
hering to the bottom and sides of the boiler, the liquor must be kept continually stirred
with a wooden rake. The object of the boiling is to drive away all the carbonic
acid that may still be present in the liquor, to remove the soluble extractive matters
which would render the indigo dull and impure, to prevent the fermentation or putre-
faction of the indigo which would otherwise take place, and lastly, to facilitate the
subsequent processes of filtering and pressing. The fire having been removed, the
liquor is allowed to stand for some time, and as soon as the indigo has settled, the
supernatant liquid is drawn off by means of taps fixed in one of the sides of the
boiler. The lowest tap is then opened, and the indigo is run off with the water and
received on a filter, consisting of blue Guinea cloth stretched on a frame. The first
portions of liquid which run through are usually coloured with indigo, and must
therefore be caught in a suitable vessel and poured on the filter again. As soon as
the liquid has- percolated, the indigo, which is now a compact paste, is removed from
the filter by means of a wooden ladle and put into a press, which consists of a wooden
box pierced with holes. The press having been lined with cloth, the indigo is put in,
the cloth is folded round it as evenly as possible, a wooden lid is dropped on the
cloth, and the mass is submitted to pressure by means of a screw, until no more liquid
runs through at the bottom, which takes place as soon as the indigo has been reduced
to about a third of its original volume. The press is then opened, the indigo is taken
out of the doth, laid on a table and divided by means of a knife into pieces of a cubical
shape. These cubes are then taken to the drying shed, where they are placed on
trellises covered with matting or very thin cloth, so as to admit of the free passage of
air. Care must be taken not to dry them too rapidly, otherwise the cakes would
crack and split into fragments, which are then of little commercial value, and it is
therefore necessary to protect them from currents of dry air by covering them with
canvas or Guinea cloth. Durbg the drying process, which occupies from 8 to 10
days, the cakes should be turned several times. They are then closely packed in
boxes, each box holding about 25 kilogrammes. The boxes should be lined with paper.
It may be remarked, that when the indigo is of good quality, the volume of the paste
diminishes very little when subjected to pressure. If the process of filtering takes up
much time and the pressing is attended with difficulty, it may be anticipated that the
indigo will turn out of bad quality. This may proceed from the plant having been
overgrown, or from the maceration or the beatmg process having been continued too
long, or from the employment of too large a quantity of lime water. The difficulty
experienced in pressing the indigo paste, and which is often so great as to cause the
cloth in which it is enveloped to break, is caused by the presence of a mucilaginous or
viscous substance mixed with the indigo, which may be removed by treating the paste
again jrith boiling water, and repeating the operations of filtering and pressing.
In regard to the state in which indigo exists in the plants from which it is derived*
and the nature of the process by which it is obtained, various opinions have been
508 INDIGO.
eutertained by cbemists. Berthollet in his work on djeing says, '* that the three parti
of the process employed have each a different object In the first a fermentation is
excited, in which the action of the atmospheric air does not intervene, since an in-
flammable gas is evolved. There probably results from it some change in the com-
position of the colouring particles themseWes ; but especially the separation or
destruction of a. yellowish substance, which gave to the indigo a greenish tint, and
rendered it susceptible of undergoing the chemical action of other substances. This
species of fermentation passes into a destructive putrefaction, because the indigo has
a composition analogous to that of animal substances. Hitherto the colouring pir-
tides have preserved their liquidity. In the second operation, the action of the air is
brought into play, which, by combining with the colouring particles, deprives them
of their solubility, and gives them the blue colour. The beating serves, at the same
time, to dissipate the carbonic acid which is formed in the first operation, and which
by its action presents an obstacle to the combination of the oxygen. The separation
of this acid is promoted by the addition of lime ; but if an excess be introduced, it
counteracts the free combination of the oxygen. The third part of the process has
for its objects : the deposition of the colouring matter, become insoluble by oombina*
tion with oxygen, its separation from foreign substances, and its desiccation, which
gives it more or less hardness, whence its appearance varies.** De Oossignj was of
opinion that volatile alkali was the agent by which the colouring matter was ex-
tracted from the plant and held in solution until volatilised by the agitation process.
Roxburgh concluded fh>m his experiments, ** that the indigo plants contain only the
base of the colour, which is naturally green ; that much carbonic acid is cUaengaged
during its extrication from the leaves ; that the carbonic acid is the agent whereby it
is probably extracted and kept dissolved ; that ammonia is not formed during the
process ; that the use of the alkalies employed is to destroy the attraction between the
base and the carbonic acid ; and that the vegetable base beings thereby set at liberty,
combines with some colourmg principle from the atmosphere, forming therewith a
coloured insoluble fecula, which falls to the bottom and constitutes indigou"
Chevreul, who was the first chemist of any eminence to examine the indigo-
bearing plants and their constituents, inferred fh>m his analyses of the Isatis tinctaria
and the Indigo/era anilj that these plants contain indigo in the white or reduced state,
in the same state in which it exists in the indigo vat ; that in this state it is held in so-
lution by the vegetable juices, and that when the solution is removed from the plant,
it is converted by the action of the atmospheric oxygen into indigo-blue. Giobert,
from an examination of the Isatis tinctoria, drew the following conclusions: — 1. In«
digo-blue does not pre-exist in the plant, but is formed during the operations by
means of which we believe it to be extracted. 2. There exists ia a small number of
plants a peculiar principle, different ft'om all the known proximate constituents of
plants, and which has the property of being convertible into indigo; this principle
may be called indigogene, 3. This principle differs from indigo in containing an ex-
cess of carbon, of which it loses a portion, in passing into the state of indigo-bloe, by
the action of a small quantity of oxygen which it takes np. 4. The loss of this
portion of carbon must be attributed to its undergoing combustion, and being coo-
verted into carbonic acid. 5. It differs in its properties from common indigo in being
colourless and soluble in water, and by its greater combustibility, which causes it to
undergo spontaneous combustion at the ordinary temperature of the atmosphere.
6. Its combustibility is enhanced by heat and by combination with alkalies, especially
lime ; it is diminished by the action of all acids, even carbonic acid. About the year
1839, the Pylogonum tinctorium^ an indigo-bearing plant indigenous to China, became the
subject of a series of investigations by several French chemists, chiefly with a view to
ascertain whether this plant, if grown in France, could be advantageously employed in
the preparation of a dyeing material as a substitute for foreign indigo. Baudrimont and
Pelletier, after an examination of this plant, arrived at the conclusion that the indigo
is contained in it as reduced indigo, in the same state as it is in woad, according to
Chevreul. . Robiquet, Colin, Turpin, and Joly, on the other hand, expressed a very
decided conviction that indigo-blue pre-exists in the plant, but not in a free state ;
that it is combined with some organic substance or substances, which render it soluble
in water, ether and alcohol ; and that the operation of potent agencies is requisite in
order to destroy this combination and set the indigo at liberty. The explanation of
Chevreul, proceeding from an authority of such eminence, and being the simplest,
has been adopted by most chemists. Nevertheless there are objections to it which
render it inadmissible. Reduced indigo is a body which is only soluble in alkalies,
and cannot, therefore, be contained as such in the juice of indigo plants, which is
mostly acid. As it also takes up oxygen with the greatest avidity, and is converted
into indigo-blue, it is difficult to conceive how the whole of it can be preserved in a
colourless state in the cells of plants, in which it must occasionally come in contact
INDIGO. 509
-with the oxygen eliminated by the vegetable organism. If these plants' contained
reduced indigo, the juice ought, moreover, to turn blue the moment it became exposed
to the atmosphere, which is not always the case. The necessity for a long process of
fermentation in oid^r to obtain the colouring matter would also not be very apparent,
the mere contact with oxygen being, it might be supposed, all that was necessary for
the purpose. The facility with which the indigo-blue is destroyed if the process of
fermentation is carried too far, is also inconsistent with the supposition that it is con-
tained in plants either as such, or in a de-oxidised state, since indigo-bhie is a body
not easily decomposed, except by very powerful agents.
In order to throw some light on this subject, an investigation was undertaken by
Schanck into the state in which indigo-blue exists in the Isatig tinctoria, or common
woad, which is the only plant indigenous to Europe that yields any considerable
quantity of the colouring matter. Schunck succeeded ih obtaining from diat plant a
substance of very peculiar properties, to which he gave the name of Indican, This
substance has the appearance of a yellow or light brown transparent syrup. It has
a bitter taste. It is very easily soluble in water, alcohol, and ether; its solutions are
yellow and have an acid reaction. Its compounds with bases are yellow. When its
watery solution is mixed with a strong acid, such as muriatic or sulphuric acid, no
change takes place at first, but on leaving the solution to stand, or on heating it, it
becomes blue and opalescent, then acquires a purple colour, and at length deposits a
quantity of purplish-blue flocks, which are quite insoluble in water. These flocks
consist for the most part of indigo-blue, but they contain also a red colouring matter
and several brown substances of a resinous nature. The supernatant liquid contains
» peculiar kind of sugar, and on being distilled, yields carbonic, formic, and acetio
acids. Hence it follows that the plant does not contain indigo-blue ready formed
either in the blue or colourless state, that the latter exists in the vegetable juice in a
state of combination with sugar, forming a compound of that peculiar class known to
chemists as glwcosides. This compound is readily dissolved by water, and the indigo-
blue may then be liberated and precipitated from the solution by means of acids, and
probably also by other agents, but the simultaneous action of oxygen is not necessary
during the process of decomposition, which the compound undergoes in yielding in-
digo-blue. Now if, as seems probable, the various species of indigofera contain indi-
can or some similar substance, the phenomena which take place during the process of
manufacturing indigo may easily be explained. During the steeping process the
indican is dissolved, and in consequence of the fermentation which then takes place
in the liquor it is decomposed into indigo-blue and sugar. The former would then be
precipitated, but since ammonia is, according to most authors, evolved at the same
time, the indigo-blue is, by the simultaneous action of the alkali and the sugar, or other
organic matters contained in the liquid, reduced and dissolved, forming a true indigo
vat, from which the colouring matter is afterwards precipitated by the combined
action of the atmospheric oxygen and the lime, during the heating process. Accord-
ing to Schunck, two distinct periods may be observed m the decomposition of indican.
During the first period, indigo-blue is the chief product of decomposition; during
the second, the red and brown resinous matters make their appearance with very
little indigo-blue. The formation of carbonic, acetic, and formic acids is, according to
Schunck, dependent on that of the brown resinous matters. It would appear, therefore,
that the copious disengagement of carbonic acid, as well as the acid taste, attributed
to acetic acid, sometimes observed during the manufacture of indigo, are phenomena
which indicate the formation, not of indigo-blue, but of other substances, which may
prove very injurious to the quality of the indigo. These substances bving soluble in
alkalies, but insoluble in water, are precipitated, as soon as the liquid loses the alka-
line reaction which it possesses at the commencement, and becomes acid. Though
indigo-blue is a body of very stable character, not easily decomposed when once formed,
except by potent agencies, still the assertion of Perottet and others, that "nothing is
more fugitive and more liable to be acted on by destructive agencies, than the colour-
ing principle of the indigoferse," will be easily, understood when the following facts,
mentioned by Schunck, are taken into consideration. If a watery solution of indican,
this indigo- producing body, be boiled for some time, it then yields by decomposition,
not a trace of indigo-blue, but only indigo-red, and if it be boiled witih the addition of
alkalies, it then gives neither indigo-blue nor indigo-red, but only the brown resinous
matters before mentioned. The mere action of alkalies is therefore sufficient to cause
the molecules, which would otherwise have gone to form indigo-blue, to arrange them-
selves in a totally different manner and yield products which bear very little resem-
blance to it It is evident, therefore, that one of the chief objects to be kept in view
by the manufacturer of indigo, is the proper regulation of the process of fermentation,
so as to prevent the formation of the other piquets, which take the place of indigo-
blue, and are formed at its expense.
610 INDIGO.
The indigo of oommeree ocean in pieces, irbicli are eometimes cnbical, soiiieliBici
of an irregolar fonn. These pieces are firm and dry, and are easily broken, the fine-
tore being doll and earthy. It is sometimes lighter, sometimes appareni!^ Iteama
than water, this dijfference depending on its being more or leas fi«e from foreign
impurities, as well as npon the treatment of its paste in the boiling, pressiiB^ and
drying operations. Its colour is blue of different shades; as light-blae, purplish-
blue, coppery-bloe, and blackish-blne. On being robbed with the nail, or a soiooth
hard body, it assumes the lustre and hue of copper. It is usually a homogeneoos mas,
but it occasionally contains grains of sand or other foreign bodies, and sometinies
presents inequalities of colour. It is frequently full of small cavities, which proceeds
from the drying process having been conducted too rapidly, and it is also oorered at
times with a whitish matter consisting of mould* It varies very much in consiateiicy,
being sometimes dry, hard, and compact, whilst sometimes it is easily broken ioto thin
fiat pieces. Indigo is devoid of smell and taste. When applied to the tongue, how-
ever, it adheres slightly, in consequence of the property which it possesses of rapidly
absorbing moisture, a property which is often hiad recourse to in wder to ascertain its
quality. When thrown on red-hot coals it yields vapours of a deep pnrpie cokxir,
which, when condensed on cold bodies, give shining needles having a coppery lustra
It is insoluble in water, cold alcohol, ether, muriatic acid, dilute solphuric acid, oold
ethereal and fat oils ; but boiling alcohol and oils dissolve a little of it, which iktj
deposit on cooling. Creosote hM the property of dissolving indigo.
Indigo varies very mnch in quality, but it requires much discrimination in order to
jodge &rly of the quality of any sample from mere inspection and application of the
tests usually employed by dealers. A cake of indigo being broken, and the nail qir
the edge of a slullmg bemg passed with a tolerable degree of pressure over the frac-
tured part, a fine coppery streak will be produced if the indigo is good. If the indigo
furrows up on each side of the nail, it is weak and bad, and if the coppery streak be not
very bright it is not considered good. When a piece of indigo is broken the fractnre
should 1^ held up to the sun, and, if it has not been well strained from the dross,
particles of sand will be seen glistening in the sun-light The outside or coat should
also be as Aree from sand as possible. When the squares are broken in the chests the
indigo fetches a low price, and if it is very mnch crushed it is only bought by the
consumers for immediate use. The methods employed for ascertaining the true amount
of colouring matter in any sample of indigo wiU be described below.
Indigo is generally classified according to the various countries from which it is
obtained. The principal kinds are the following : — Bengal, Onde, Madras, Manilla,
Java, Egyptian, Guatemala, Caraccas, and Mexican.
At the present day the finest qualities of indigo are obtained from Bengal, the pro-
duce of that country having now taken the place in public estimation which was once
occupied by that of the Spanish colonies. The export of indigo from Bengal, which
in 1853 amounted to 120,000 maunds Cof 74 lbs. 10 oz.), would require for its culture
about 1,025,000 acres, and an annual expenditure of l,300,000i!. Of this extent of
land about 550,000 acres is believed to be included in the Lower Provinces, and con-
sists chiefly of alluvial land rescued from the rivers. The best qualities of Bengal
indigo are manufactured in the Jessore and Kishenaghaur districts, but each district
produces a quality peculiar to itself, and dififerences of a less striking character may
be perceived in the produce of different factories. The Bengal indigo, when packed
in chests, consists of four principal qualities, viz., the blue, purple, violet, and copper.
But these kinds, by passing over into one another, produce a number of intermediate
varieties, such as purply blue, blue and violet, purply violet, && The Tarions quali-
ties would, therefore, be distinguished as follows : — 1. Blue. 2. Blue and violeC
8. Purple. 4. Purple and violet 5. Violet 6. Violet and copper. 7. Copper.
The leading London brokers, however, classify Bengal indigo into the following
grades : — fine blue, fine purple and violet, fine red and violet, good purple and viidet,
middling violet, middling defective, consuming fine, middling and good, ordinary,
ordinary and lean trash. The finest qualities of Bengal indigo present the following
characteristics. They consist of cubical pieces, are light, brittle, of a clean fracture,
soft to the touch, of a fine bright blue colour, porous, and adhering to the tongue. The
lower qualities have a duller colour, assume more and more of a reddish tinge, are
heavier, more compact, and less easily broken.
The indigo from the upper provinces of India comes chiefly from Tyroot, Onde,
and Benares. It is inferior to Bengal indiga
Of Madras indigo there are two kinds, viz. : 1. Dry leaf, made from dry stacked
leaves ; and 2. Kurpah, which is manufactured from the wet leaf in the same way as
Bengal indiga The latter has only come into use since 1830. Both are of inferior
quality to Bengal indigo.
The Manilla indigoes present the marks of the rushes npon which they have been
INDIGO. 611
dried. The pieoes are either oabical, or fiat and sqaare, or of irregular shape. The
aoality is Terj uneqoaL JaTa indigo occurs in flat, square, or lozenge-shaped masses,
le qoaUtj approaching that of Bengal Both these kinds are consumed chiefly on
the continent of Europe.
Gnatemala indigo is imported into this conntry in serons or hide wrappers, each
oontainitt^ about 150 lbs. net It occurs in smaU irregular pieces, which are more
or less bnktle, compact, lighter than water, and of a bright blue colour with an occa-
aional tinge of yiolet There are three kinds of Guatemala indigo^ yiz. : 1. Flores,
which is the best, and approaches in quality, that of the finer JE^ngai indigoes ; 2.
Sobres; and 3. Cortes, which is the lowest in quality, being heayy, difficult to break,
and of a coppery-red colour. Of the first kind very little now reaches the market.
The indigo of Garaccas is, generally speaking, inferior to that of Guatemala.
The mann&cture of indigo was formerly carried on in St Domingo, but has for
•ome time been entirely abandoned. •
The indigo of commerce, even when not adulterated, is a mixture of different
matters. When it is heated in a state of fine powder to 2\2^ F. it loses from 5 to 10
per cent in weight, the loss consisting of water. When the dry powder is heated in
a crucible, a great part of it burns away, and there is left at last a greyish ash, con-
sisting of the carbonates and phosphates of lime and magnesia, sulphate of lime, alu-
mina, oxide of iron, day, and sand. These matters are partly derived from the plant,
partly from the lime and the impurities of the water employed in the maouikcture.
The quantity of inorganic matter contained in ordinary indigo varies very much. In
the better qualities it amounts on an ayerage to about 10 per cent of the weight $
whilst in the inferior qualities, especially of Madras indigo, it often rises to between
80 and 40 per cent The organic portion of the indigo, or that which is dissipated
when indi^ is heated, also consists of several different substances.
By treating indigo with various solvents, Berzelius obtained, besides indigo-blue, the
true colouring matter of indigo, three other bodies, via. ijuUffo-gluten, iiidigorhroum^ and
indigo-nd, which seem to be contained in various proportions in all kinds of indigo.
Indigo-gluten is obtained by treating indigo with dilute sulphuric, muriatic, or acetic
acid, and then with boiling water, ft is left on evaporation of its solutions as a yellow
transparent extract, which is soluble in spirits of wine, and easily soluble in water,
more difficultly in acid liquids. Its taste is like that of extract of meat It yields by
dry distillation much ammonia and a fetid oil, and behaves in most respects like vege-
table gluten. ^ On treating the- indigo, after being freed fipom the indigo-gluten, with hot
strong caustic lye, the indigo-brown together with a little indigo-blue dissolves,
forming a dark brown, almost black solution, from which the indigo-brown after fil-
tration fh)m the portion insoluble in alkali is precipitated by means of acid. After
being purified, indigo-brown has the appearance of a dark brown transparent resin,
which is almost tasteless and quite neutral. By dir distillation it affords ammonia and
empyreumatic oil It is decomposed by nitric acid and chlorine. It combines both
with acids and bases. Its compounds with alkalies are dark brown, and easily soluble
in water. The compound with baryta is not easily soluble in water, and that with
lime is insoluble. By boiling the allEaline compounds with lime in excess the indigo-
brown may be separated and rendered insoluble. The green substance obtained by
Chevrenl from indigo seems to have been a compound of indigo-brown with ammonia
containing a little indigo-blue, either in a state of combination or mechanically inter-
mingled. Indigo- brown seems to bear a great resemblance in many of its properties to
the brown resinous substances obtained by Schunck in the decomposition of indican with
acids. From its constant occurrence in all kinds of indigo, it may be inferred that it is
not a mere accidental impurity, but stands in some unknown relation to indigo-blue. As
long, however, as its origin and composition are unknown, this must remain a mere
supposition. After the removal of the indigo-gluten and indigo-brown, the indigo is
exhausted with boiling alcohol of specific gravity 0*83. A dark red solution is obtained,
which is filtered and distilled, when the indigo-red contained in it is deposited as a
blackiah-brown powder, which is quite insoluble both in water and in alkaline liquids.
Indigo-red, according to Berzelius, is amorphous, but by distillation in vacuo yields a
white crystalline sublimate, as well as unchanged indigo-red. Concentrated sulphurie
acid dissolves it, forming a dark yellow solution, which deposits nothing on being mixed
with water ; the diluted solution is rendered colourless by wool, which at the same time
acquires a dirty yellowish-brown or red colour. The description given by Berzelius
leaves it doubtful whether the indigo-red obtained by him fh>m indigo was a pure
unmixed substance. From the leaves of the indigoferse, as well as from those of the
Isatis Hnctona, a substance may, according to Schunck, be extracted which has re-
ceived from him the name of indirubinet but which seems to be merely indigo-red in a
state of purity. This substance has, according to Schunck, the following properties :
it crystallises in small silky needles of a brownish-purple colour, which when rubbed
512 INDIGO.
with a hard body Bhow a slight bronze-like lastre. When earefall^r heated it may be
entirely volatilised, yielding a yellowish-red vapour, which condenses in the form of long
plum-coloured needles, having a slight metallic lustre. It dissolves in concentrated
sulphuric acid, forming a solution of a beautiful purple colour, which when dilated
with water yields no deposit and then imparts a fine purple colour to cotton, wool, and
silk. It is insoluble in water, but dissolves in boiling alcohol with a splendid purple
colour. It is insoluble in alkalies, but dissolves when exposed to the combined action
of alkalies and reducing agents, just as indigo-blue does, forming a solution from
which it is again precipitated on exposure to the oxygen of the atmosphere. This
solution dyes cotton purple. In most of its properties this body bears a striking re-
semblance to indigo-blue, and the composition of the two is identical.
It has been doubted whether these various substances or impurities with which
indigo-blue is associated produce any effect in the dyeing process on cotton. In a
memoir by Schwarzenberg, to which a prize was awarded by the Societe Indostrielle
de Mulhouse, the author arrives at the conclusion that neither indigo-gluten, indigo-
brown, nor indigo-red gives rise to any appreciable effect when added to an indigo vat
prepared with pure indigo-blue. Nevertheless differences are observable in dyeing with
different kinds of indigo, which can only be explained on the supposition that some-
thing besides indigo-blue takes part in ihe process. In the ordinary blue vat, made
with copperas and lime, any effect which might be produced in dyeing, by the indigo-
brown is neutralised by the lime, which forms with it an insoluble compound. Indigo-
red, however, dissolves, as mentioned above, in contact with alkalies and reducing
agents, and the solution imparts a purple colour to cotton. In the ordinary indigo
vat its presence may be detected by precipitating a portion of the liquor, and treating
the precipitate with boiling alcohol, which then usually acquires a red colour. It is
possible, therefore, that a small part of the effect produced in dyeing with indigo may
be due to indigo-red.
That portion of the indigo which remains after treatment with acid, alkali, and
alcohol consists essentially of indigo-blue, the true colouring matter of indigo, mixed,
however, with sand, earthy particles, and other impurities. In order to purify it, the
residue, while still moist, is to be mixed with lime, the quantity of which must amount
to twice the weight of the crude indigo, and which has been previously slaked with
water. The mixture is then put into a bottle capable of holding about 150 tim»
its volume of water, and the bottle is filled up with boiling water and shaken. A
quantity of finely powdered protosulphate of iron, amounting to ) of the weight of
the lime is then added, the bottle is closed with a stopper, well shaken, and left
to stand for several hours in a warm place. The mass gradually becomes green, and
the indigo-blue is then converted by the precipitated protoxide of iron into reduced
indigo, which dissolves in the excess of lime, forming u deep yellow solution. This
solution when clear is poured off from the deposit into a vessel containing a sufficient
quantity of dilute muriatic acid to supersaturate the whole of the lime. The reduced
indigo which is precipitated in greyish-white flocks, is agitated with water until it has
become blue, and the regenerated indigo-blue is collected on a filter and washed with
water, in order to remove the chloride of calcium and excess of muriatic acid. The
following method of obtaining pure indigo-blue has been recommended by Fritzsche :
4 oz. of crude indigo and the same weight of grape sugar are put into a lx>ttle capable
of holding 12 lbs. of water; a solution of 6 oz. of concentrated caustic soda lye in
alcohol is then added, after which the bottle is filled with hot spirits of wine of 75 per
cent. , and the whole is left to itself for some time. The liquid becomes at first wine-nd,
then yellow, and on being filtered and left exposed to the air, deposits the indigo-bloe
in small crystalline scales, which are to be filtered off and washed at first with alcohol,
and then with water.
Pure indigo-blue has the following properties :» Its colour is dark blue inclining to
purple. When rubbed with a hard body it assumes a bright coppery lustre. It has
neither taste nor smell, possesses neither acid nor basic properties, and belongs, as
regards its chemical affinities, to the class of indifferent substances. Its specific gravity
is 1*50. When heated in the open air it melts, boils, and burns with a smoky flame,
leaving a carbonaceous residue. But when it is heated in a vessel partially dosed, or
in vacuo, it begins to evolve at a temperature of about 650° F. a violet coloured
vapour, which condenses on the colder parts of the apparatus in the form of long
crystalline needles, which are blue by transmitted light, but exhibit by reflected light
a beautiful coppery lustre. These needles are unchanged indigo-blue. A. great
portion of the indigo-blue is however decomposed during the heating process. Indigo-
blue is insoluble in water, alkalies, and dilute acids. Boiling alcohol and boiling oil
of turpentine dissolve a minute quantity of it, and deposit it again on cooling. Fixed
oils also dissolve a little of it at a heat exceeding that of boiling water, yielding blue
solutions, the colour of which, when the heat is further increased, changes, according
INDIGO. 513
to Mr. Cnun, first to crimson and then to orange. By the action of dilate nitric and
chromic acids indigo-blne is decomposed and converted into igatine, a body soluble in
water and crystallising in red needles. Chlorine also decomposes indigo-blue,
changing it into chlorigatine, a substance having properties very similar to those of
isatine. Both isatine and chlorisatine afford with different reagents a great number
of products of decomposition, none of which have, however, as yet found any applica-
tion in the arts. By the long continued action of boiling nitric acid indigo-blue is
converted, first into indigotic acid, a white crystalline acid, and then into nitropicric
aeid, which is yellow and crystallised. The latter is sometimes employed for impart-
ing a yellow colour to silk and wool, but it is generally prepared from cheaper
materials than indigo- blue. The action of concentrated sulphuric acid on indigo-
blue is very remarkable. When the acid is poured on the pure substance and gently
heated it acquires in the first instance a green colour, which changes after some time
to blue. No gas of any kind is evolved. When however crude mdigo is employed,
there is a perceptible disengagement of sulphurous acid, resulting from the action of
the sulphuric acid on the impurities of the indigo, stich as the indigo-gluten, &c.
On adding water, a solution of a beautifhl deep blue colour is obtained. The filtered
liquid contains a peculiar acid, to which the names of indigO'tulpkuric, sulphindit/otic,
sJlphintfylic, or eearuleo'Sulphuric acid have been applied.
This acid is a so-called double acid. It contains indigo-blue and sulphuric acid, but
in such a peculiar state of combination! that neither of the two constituents can be
detected by ordinary re-agents, nor again eliminated as such from the compound*
It combines with bases, without either of the two constituents separating. The com-
pounds are called indigo-sulphatea, and are, like the acid, of a dark blue colour.
When the solution of indigo-blue in concentrated sulphuric acid is diluted with water,
there is usually formed a small quantity of a dark blue fiocculent precipitate, which is the
phenicine of Mr. Cmm, or the indigo-purple of Berzelius. It is a compound of indigo-
blue with sulphuric acid, containing less of the latter than indigo-sulphuric acid. It
is always formed when the quantity of sulphuric acid employed is not more than
eight times that of the indigo-blne, or when the action of the acid on the latter has con*
tinned for only a short time. By heating it with an excess of acid it is changed into
indigo-sulphuric acid. Though soluble in concentrated sulphuric acid, it is insoluble
ill the dilute acid, and hence is precipitated on the addition of water. On filtering
and washing, however, it begins to dissolve, as soon as the free sulphuric acid has
been removed, and may then be completely dissolved by pure water. The solution
has a blue colour, just like that of indigo-sulphuric acid. Its compounds with bases
have a blue colour with a purplish tinge. The blue acid liquid filtered fh>m the in-
digo-purple on being supersaturated with carbonate of potash or soda, deposits a dark
blue powder, which consists of the indigo-sulphate of potash or soda. These compounds
are insoluble in water containing a large quantity of neutral salts, and are therefore
precipitated when the excess of sulphuric acid is neutralised by carbonate of potash
or soda. As soon, however, as the sulphate of potash or soda has been removed by
washing, the indigo-sulphate may be dissolved in pure water, yielding a dark-blue
solution. The indigo-sulphates of the alkalies may also be prepared by steeping
wool, previously well cleaned, into the solution in sulphuric acid. The wool takes up
the colour, becoming of a dark blue colour, and after having been well washed with
water, in order to remove the excess of acid as well as the impurities which are
always present in the solution when crude indigo has been employed, is treated with
carbonate of potash, soda, or ammonia, which separate the acid from the wool, and
produce blue solutions containing the salts of the respective bases. The indigo-
sulphates of the earths and metallic oxides, which are mostly insoluble blue powders,
may be obtained from the alkaline salts by double decomposition. By an excess of
caustic alkali, iu^go- sulphuric acid is immediately decomposed, giving a yellow
solution, from which it is impossible to obtain the acid again. By means of reducing
agents, such as sulphuretted hydrogen, nascent hydrogen, protosalts of tin and iron,
&C., indigo-sulphuric acid is decolorised, but the colour is restored by the oxygen
of the atmosphere. Indigo-sulphuric acid, in a free state or in combination with
alkalies, is employed in the arts for the purpose of imparting a blue colour to silk
and wooL It has very little affinity for cotton fibre, but is nevertheless employed
occasionally for blueing white cotton-yam and other bleached goods.
By treatment with strong boiling caustic potash or soda lye, indigo-blue is gradually
decomposed and converted into a colourless crystallised acid, anthranUic acid. By
weak solutions of caustic alkalies, it is not in the least affected. If, however, it be
subjected to the combined action of an alkali or alkaline earth and some body
having a strong affinity for oxygen, such as protoxide of iron or tin, sulphur, sul-
phurous or phosphorous acid, or organic matters, such as grape-sugar, &c., it
disappears by degrees, yielding a yellow solution, containing in the place of indigo-
Vou IL L L
514 INDIGO.
bine anotbeT 8al)stance, 'which has been called indigo-whiiet mdiffogene, or redmeed
indigo. When an excess of some acid is added to the yellow solution, the indigo-
-white is precipitated in white or greyish-^hite flocks, -which on filtration and exposure
to the atmosphere rapidly become blue, and are reconverted into indigo-blue.
Indigo-white is insolable in water, bat slightly soluble in alcohol It is soluble in
caustic alkalies, lime and baryta water. The solutions on exposure to oxygen become
covered with a pellicle of regenerated indigo-blue. With an excess of lime it gires
an insoluble compound. Its compounds with alumina and metallic oxides, which ajre
insoluble in water, may be obtained by double decomposition. Salts of oxide of
copper, when added to its solutions in alkali, convert it immediately into indigo- blue,
the oxide of copper being reduced to suboxide. Indlgo-blne is also converted into
indigo white, when it is exposed to the action of fermenting or putrefying substances,
in the presence of water. Here the decomposing organic matter is the reducing
agent, and ammonia, which is usually formed during &e process of putrefaction, is
the solvent of the indigo- white. If a piece of cotton, wool, or silk be dipped into an
alkaline solution of indigo-white and then exposed to the atmosphere, it acquires a
blue colour, which may be made deeper by repeated dippings, and subsequent
exposure. It is on this property of indigo-white that the dyeing with indigo depends.
The true chemical formula of indigo-blue, which was first discovered by Mr. Cmm,
is C'*H'NO, and* 100 parts contain therefore by calculation 73*28 carbon, 3 SI
hydrogen, 10'68 nitrogen, and 12'23 oxygen. The formula of indigo- white is
CH^NO*, and it differs therefore from indigo-blue by containing I atom more of
hydrogen, which is taken up during the so-called reduction of the latter, and lost
again by oxidation during its reconversion into indigo-blue.
Since the value of indigo depends entirely on the quantity of indigo-blue which it
contains, it is of great importance to ascertain the exact amount of the latter in any
given sample of the article. Before commencing the determination of the indigo-
blue, a weighed portion of the indigo ought to be heated for some hours at 212^ F.,
and then weighed again. The loss in weight which takes place represents the amount
of water contained in the sample. A weighed quantity of the dried indigo is then
to be heated over the flame of a lamp until all the organic matter has been burnt
away. By weighing the residue which is left the amounf of ash or inorganic matter
is ascertained. In order, in the next place, to determine the amount of indigo-blue,
seviTal methods have been devised by various chemists, none of which howevtr
yield very accurate results. Of these methods the following are the principal ones:
1. A weighed quantity of finely pounded indigo is rubbed with water in a porcelain
mortar. An equal weight of pure lime is then slaked with water and the hydrate is
well mixed with the indigo. The mixture is then poured into a stoppered bottle of known
capacity, and the mortar is well rinsed with water, which is added to the rest. The
bottle is now heated in a water-bath for several hours, and a quantity of finely pounded
sulphate of iron is added ; the bottle is then filled up with water, the stopper is in-
serted, and after the contents have been well shaken the whole is allowed to repose for
some hours, until the indigo has become reduced and the sediment has sunk to the
bottom. A portion of the clear liquor is then drawn off with a siphon, and the
quantity of liquid haying been accurately measured, it is mixed with an excess of
muriatic acid, and the precipitate, after having been oxidised, is collected on a weighed
filter and well washed with water. Lastly, the filter with the indigo-blue is dried
at 212^ F. and weighed, and the weight of the filter having been subtracted from
that of the whole, the weight of the indigo-blue is ascertained. Supposing now that
the whole quantity of liquid had been 200 measures, that 50 measures had been
drawn off yielding 10 grains of indigo-blue, then the sample contained on the whole
40 grains of the latter. For 60 grains of indigo it is necessaxy to take from lib.
to 2lb8. of water.
According to Mr. John Dale of Manchester, who has had great experience in the
valuation of indigo for practical purposes, this method, though rather long and tedious,
still gives more accurate results than any other. The quantity of indigo-blue in-
dicated by it is generally below the actual quantity contained in the sample. Accord-
ing to Berzelius this loss arises from the lime forming an insoluble compound with a
portion of the reduced indigo- blue. Mr. Dale, however, is of opinion, that even when
every precaution has been taken, a certain loss, proceeding from some hitherto un-
ascertained cause, cannot be avoided. When for instance pure indigo-blue is treated
with lime and copperas in the manner just described, the quantity which is again
obtained by precipitation from any portion of the liquid is always less than what
it should be by calculation, even when no excess of lime has been employed.
8. The second method of determining the indigo-blue is performed as follows.
About 15 or 20 grains of pure indigo- blue, obtained by precipitation fVom an indigo
▼at, and the same quantity of the indigo to be tested, which must be previously ground
INDIGO. 515
to a fine powder, are weighed off. and each of them is treated with ahont 12 times its
weight of concentrated sulpharic acid in a fiask or porcelain basin. After being
heated at a temperature of 120° to 140° F. for aboat 24 hours, and occasionally well
agitated, the two liquids are mixed with water, so Uiat the volume of the two shall
be exactly equal. Two equal measures of a weak solution of hypochlorite of lime
are then taken, and to the first is added a quantity of the solution of pure indigo.
The chlorine liberated by the excess of sulphuric acid in the solution destroys the
blue colour of the indigo-sulphuric acid. More of the solution must be added until
the liquid begins to acquire a greenish tinge, and the number of measures necessary
for the purpose is noted. The same experiment is then made wiUi the solution of
crude indiga The quantity of indigo-blue in the latter is of course in inrerse ratio
to the number of measures which are requisite in order to take up the whole of the
chlorine which is liberated. If, for example, the same quantity of hypochlorite of
lime decolorises 167 measures of the solution of pure indigo-blue and 204 measures
of the solution of crude indigo, then the quantity of indigo-blue contained in 100 parts
of the latter is given by the following proportion ; 204 .' 167 :: 100 : x s81*8.
A number of samples of indigo may be tested in this manner at the same time.
Care most be taken to prepare a fresh solution of indigo-blue for every series of trials,
since this solution undergoes a change on standing, which renders it quite inapplicable
as a standard of comparison. It is necessary also to pay great attention at the
moment when the greenish colour indicating an excess of the sulphate of indigo
begins to appear, for it will often be found that this colour disappears after standing a
few minutes, and a fresh quantity of the blue solution must then be added cautiously,
until the greenish tinge becomes permanent, even after standing for some time.
Modifications of this process have been introduced by various chemists by the use of
permanganate of potash, chlorate of potash, or bichromate of potash, in the place of
hypochlorite of lime ; but as the principle on which the process depends is in each
case identical and.the modus operandi is almost the same, it will be unnecessary to enter
into any minute description of these modifications. The whole method is, however,
open to serious objections, and the results which it affords cannot at all be depended
on. In the first place, it is difficult to institute a strict comparison between the dif-
ferent shades of colour resulting ft«m the decomposition of the sulphate of indigo in
different cases, since the pure green tinge observed when an excess of the pure
sulphate has been added to the decomposing agent, gives place to a dirty olive or
brownish-gjeen, when a solution of crude indigo is employed, in consequence of the
impurities contained in the latter. Secondly, it is almost impossible to avoid the
formation of a certain quantity of sulphurous acid during the action of concentrated
sulphuric acid on crude indigo. This sulphurous acid during the following operation
becomes oxidised before the blue sulphate is destroyed, and hence the percentage of
indigo-bhie is apparently raised. In employing this method, it is common to find
more than 80 per cent of indigo-blue in a good sample of indigo, whereas the best
qualities seldom contain above 60 per cent, and average qualities between 40 and SO
per cent This method may show a percentage of 70 indigo-blue, when the method
first described indicates between 50 and 60.
8. The third method of estimating the indigo-blue is performed in the following
manner. Equal weights of the samples to be tested are treated with equal quantities
of concentrated sulphuric acid in the manner above described, and the solutions are
then diloted with water and introduced into graduated glass cylinders, water being
added to each until they all exhibit exactly the same shade of colour. The richer
the sample is in indigo-blue, the greater will be the quantity of water necessary for
this purpose, the number of measures of water required in each case indicating the
relative amount The great objection to this metiiod consists in the circumstance,
that the different kinds of indigo do not give the same shade of blue when their solu-
tions in sulphuric acid are dQuted with water, some exhibiting a pure blue 'colour,
others a blue with a greenish, or purplish tinge. It therefore becomes difficult to in-
stitute an exact comparison between them.
Empkyment of indigo in dyeing, — As indigo-blue is insoluble in water, and as it can
penetrate the fibres of wool, cotton, silk, and flax only when in a state of solution, the
dyer must study to bring it into this condition in the most complete and economical
manner. This is effected either by exposing it to the concurrent action of alkalies
and of bodies which have an affinity for oxygen superior to its own, such as certain
metals and metallic oxides, or by mixing it with fermenting matters, or finally, by
dissolving it in a strong acid, such as the sulphuric. The first method is that which
is employed in the
Copperas or common hhte vat — Before being used the indigo must be broken into
small pieces, the size of nuts, moistened with hot water, and then left for a day ; after
LL 2
516
INDIGO.
which it is redaced to a soft paste in a mill. The indigo mill ia repreaented in Jigt.
990, and 991.
fl, is a four-sided iron cistern, 2 feet 11 inches long, 19 inches hroad, and 18 incbea
deep, cylindrical or rounded in the bottom, and resting npon gndgeoos in a wooden
frame. It has an iron lid 6, consisting of two leases, between which the rod c mores
to and fro, receiTing a Tibratory motion from the crank i. By this constmction, a
frame e, which is made fast in the cistern by two points if tf, is caused to Tibnle, and
990
•8
Ci
• \ t
I
9
[a ({
a
^m;
to impart its swing movement to six iron Toilers/, f^f, fonr inches in diameter, three
being on each side of the frame, which triturate the indigo mixed with water into a
fine paste. This mill is capable of grinding 1 cwt of indigo at a time. Whenerer
the paste is uniformly groond, it is drawn off by the stopcock g, which had been
previously filled up by a screwed plug, in order to prevent any of the indigo from
lodging in the orifice of the cock, and thereby escaping the action of the roUersL
Mills of other forms are also used occasionally. One of these consists of a lieiiii-
spherical iron vessel open at Ihe top, in which a stone of corresponding shape is fixed,
8o as to leave a small space between it and the sides and bottom of the vessel, in which
the indigo undergoes the necessary trituration with water, the motion being prodoeed
by means of a vertical shaft fixed to the centre of the stone.
The other ingredients necessary for setting the vat are copperas or protoanlpltate
of iron, newly slaked quicklime, and water. Various proportions of these ingredients
are employed, as for instance, 1 part by weight of in£go (dry), 3 parts of copperas,
and 4 of lime ; or 1 of indigo, 2j^ of copperas, and 8 of lime; or 8 of indigo, 14 of'
copperas, and 20 of lime ; or 1 of indigo, | of copperas, and 1 of lime. The snlphale
of iron should be as free as possible from the red oxide of iron, as well as from solpkate
of copper, which would re-oxidise the reduced indigo-blne. The vat having been
filled -with water to near the top, the materials are introduced, and the whole after
being well stirred several tunes is left to stand for about twelve hours. The chemical
action which takes place is very simple. The protoxide of iron which is set at libertj
by the lime reduces the indigo-blue, and the indigo-white is then dissolved by the
excess of lime, forming a solution, which, on being examined in a glass, appears per^
fectly transparent and of a pure yellow colour, and becomes covered wherever it
comes into contact with the air, with a copper-coloured pellicle of regenerated indigo-
blue. The sediment at the bottom of the vat consists of sulphate of lime, peroxide of
Iron, and the insoluble impurities of the indigo, such as indigo-brown In combination
with lime, as well as sand, clay, &c. If an excess of lime is present, a little reduced
indigo-blue will also be found in the sediment in combination with lime.
The copperas vat is employed in dyeing cotton, linen, and silk. For cotton goods
no other kind of vat is used at the present day. The dyeing process itself is very
simple. The vat having been allowed to settle, the goods are plunged into the dear
liquor, and after being gently moved about in it fbr some time are taken out, allowed
to drain, and exposed to the action of the atmosphere. Whilst in the liquid Uie &bric
attracts a portion of the reduced indigo-blue. On now removing it from the liquid it
appears green, but soon becomes blue on exposure to the air in consequence <«f the
oxidation of the reduced indigo-blue. On again plunging it into the vat, the de-
oxidising action of the latter does not again remove the indigo-blne which has been
deposited within and around the vegetable or animal fibre, but on the contrary, a
f^sh portion of reduced indigo-blue is attracted, which on removal fh>m the liquid is
again oxidised like the first, and the colour thus becomes a shade darker. Br repeat-
ing this process several times, the requisite depth of colour is attained. This effect
cannot in any case be produced by one immersion in the vat, however strong it may
be. The beauty of the colour is increased by findly passing the goods through
INDIGO. 617
dflated talphnrio or mnmtie acid, which removes the adhering lime and oxide of
iron. Alter being naed for iome time the vat should be refreshed or fed with copperas
and lime» npon which oocasion the sediment most first be stirred op, and then allowed
to settle again, so as to leave the liqnor clear. The indigo-blae, however, is in coarse
of time gradoally removed, and bj degrees the vat becomes capable of dyeing only pale
shades of blue. When the eoloor produced by it is only very &int, it is no longer worth
while using it, and the contents are Uien thrown away. In dyeing cotton with indigo,
it seems to be essential that the reduced indigo-blue should be in combination with
lime. If potash or soda be used in its stead it is impossible to obtain dark shades
of blue.
When cotton piece goods are to be dyed of a uniform blue, they are not submitted
to any preparatory process of bleaching or washing. Indeed the sise contained in
nnbleadied goods seems rather to fiscilitate than to impede the dyeing process. In
dyeing these goods a peculiar roller apparatus is employed. When certain portions
of the fabric are to retain their white colour a different plan is adopted. The pieces
having been bleached, those portions which are to remain white are printed with so-
called retistt. These resists consist essentially of some salt of copper, mixed with an
iq»pn^riate thickening material. The copper salt acts by oxidising the reduced
indigo-blue at the sur&oe, and thus rendering it insoluble before it can enter the in-
terior of the vegetable fibre, since it is only when deposited within the fibre itself
that the colouring matter becomes durably fixed. The pieces are now stretched
upon square dippmg frames, made of wood or of iron, ftimished with sharp hooks
or points of attachment These frames are suspended by cords over a pulley, and
thus immersed and lifted out alternately at proper intervals. In dyeing, a set of
10 vats is used, the first vat containing 5 or 6 lbs. of indigo, and the quantity in-
creasing gradually up to 80 lbs. in the last vat The pieces are dipped for 7^
minutes in the first vat, then taken out and exposed to the air for the same length of
time, then dipped in the second vat, and so on to the last After passing through the
last vat, a small bit of the calico is dried, in order to see whether the colour is suffi-
ciently dark. If it is not, tibe whole series must be dipped once more in the same
vat in which the last dipping was performed. When the bottom of the vat is raked
np so as to have more lime in suspension, the vat becomes what the dyer calls hard,
ihMt is to say, the oxide of copper of the resist is precipitated in a compact state, and
consequently acts with more efficiency. But when the vat has been at rest for some
time, and there is little lime in suspension, then it is called aqft. When it is in this
state, the oxide of copper is thrown down in a bulky form, and when the pieces are
afterwards agitated in the liquor, in order to detach the oxide of iron, which always
floats about in the vat, and attaches itself to the fabric, and which if left adhering
would cause light stains, technically called grounding ; then the oxide of copper is
also detached, and the indigo penetrates to those parts which are to remain white.
When cotton yam is dyed in the copperas vat, the latter is generally heated by means
of steam pipes passing through the lujuor, the object being to give to the colour the
peculiar gloss or lustre, which is required in this class of goods. No preparatory
process is required, except simply steeping in hot water. In dyeing, wooden pins are
put through the hanks, their ends resting on supports passing over the top of the vat,
and the yam is then slowly turned over, one half being in the liquor, the other half
over the pins. It is then taken out, wrung, exposed to the air, and again dipped, this
operation being repeated until the requisite shade is obtained.
The methods employed for producing the colours called China hUte and pencil blue
on calico have been described under cSico Printing.
The vrnie vat is prepared bv digestion of the ground indigo in warmed stale urine,
which first deoxidises the indigo-blue, and then dissolves it by means of its ammonia.
Madder and alum are likewise added, the latter being of use to moderate the fermen-
tation. This vat was employed more commonly formerly than at present, for the
poTMse of dyeing woollen and linen goods.
Wood vaL — In former times, woad was the only material known to the dyers of
Europe for producing the blue colour of indigo. For this purpose it was previously
submitted to a peculiar process of fermentation, and the product was named paetd in
France. For most purposes indigo has taken the place of woad in the dye-house,
and for cotton goods it is now used alone. In the dyeing of woollen goods, however,
the use of woad has been retained to the present day, for the purpose rather of ex-
citing fermentation and thus reducing the indigo which is employed at the same
time, than of imparting any colour to the material to be dyed. Indeed, the woad
used by woollen dyers in tms country contains no trace of colouring matter. Various
aabstitotes, such as rhubarb leaves, turnip tops, weld, and other vegetable matters^
iiave accordingly been tried, but without success, since the fermentation is more
steadily maintained by means of woad than by any other material Pastel» which
ll3
518 INDIGO.
does COD tain a little blae coloaring matter, is preferred to iroad by many of tbe
French dyers. The materials employed in the ordinary ivoad or pastel vat, in ad-
dition to woad and indigo, are madder, bran, and lime. In the so-called Indian tgrpot-
a$h vat, madder, bran, and carbonate of potash are nsed ; in the German tut, Iwan,
carbonate of soda, and qaicklime, without woad. The chemical action which takes
place in the woad rat is not difficolt to understand. The nitrogenoos matters of die
woad begin, when the temperatore it raised, to enter into a state of fermentation,
which is kept up by means of the sugar, starch, extractiTC matter, &c^ of Uie mad-
der and bran. In consequence of the fetmentation, the indigo-blue becomes reducedf
and is then dissoWed by the lime, thus rendering the liquid fit for dyeing. Great
care is necessary in order to prerent the process of fermentation from passing into
one of putrefaction, which if allowed to proceed would lead to the entire dcatnicuon
of the indtgo-blue in the liquor. If any tendency to do so is observed, it is airested
by the addition of lime, which combines with the acetic, lactic, and other organic
acids that commence to form when putrefaction sets in. On the other hand, an
excess of lime must also be avoided, since the reduced indigo-blue is thereby ren-
dered insoluble, and unfit to combine with the materiaL
The following account of the method of dyeing woollen goods with indigo, as carried
on at present in Yorkshire, may suffice to give a general idea of the process : —
The dye- vats employed are circular, having a diameter of 6 feet 6 inches, and a
depth of 7 feet, and are made of cast iron f of an inch in thickness. They are aor-
roanded by brickwork, a space of S inches in width being left between the brickwork
and the iron, for the purpose of admitting steam, by means of which the rats are
heated. The interior surface of the brickwork is well cemented. In setting a vat
the following materials are used : — 5 cwt. of woad, SO lbs. of indigo, 56 Iba of braiv
7 lbs. of madder, and 10 quarts of lime. The woad supplied to the Torkahire dyers
is grown and prepared in Lincolnshire. It is in the form of a thick brownish-yellow
paste, having a strong ammoniacal smelL The indigo is ground with water in the
usual manner. The madder acts in promoting fermentation, but it also serves to give
a reddish tinge to the colour. The lime is prepared by putting quicklime into a
basket, then dipping it in water for an instant, lifting it out again, and then passing it
through a sieve, by which means it is reduced to a fine powder, called by the dyers
ware. The vat is first filled with water, which is heated to 140° Fahr., after which
the materials are put in, and the whole is w.ell stirred until the woad is dissolved or
diffused, and it is then left to stand undisturbed over night At 6 o'clock the next
morning the liquor is again stirred up, and 5 quarts more lime are added. At 10
o'clock, 5 pints of lime are again thrown in, and at 12 o'clock the heat is raised to ISOP
Fahr., which temperature must be kept up until 3 o'clock, when another quart of lime
is introduced. The vat is now ready for dyeing. When the process of fermentatioB
is proceeding in a regular manner, the liquid, though muddy fW>m insoluble vegetable
matter in suspension, is of a yellow or olive-yellow colour ; its surface is covered
with a blue fh>th or a copper-coloured pellicle, and it exhales a peculiar ammoniacal
odour ; at the bottom of the vat there is a mass of undissolve matter, of a diitj
yellow colour. If there is an excess of lime present, the liquor has a dark green
colour, and is covered with a greyish film, and when agitated, the bubbles which are
formed agglomerate on the surface, and are not easily broken. Cloth dyed in a
liquor of this kind loses its colour on being washed. This state of the vat is remedied
by the addition of bran, and is of no serious consequence. When, on the other hand,
there is a deficiency of lime, or in other words, when the fermentation is too active^
the liquor acquires first a drab> then a clay-like colour ; when agitated, the bubbles
which form on its surface burst easily, and when stirred up from the bottom with a
rake it effervesces slightly, or frett as the dyers say. If the fermentation be not
checked at this stage, putrefaction soon sets in, the liquid begins to exhale a fetid odour,
and whenatirred evolves large quantities of gas, which bum with a blue flame on the
application of a light The indigo is now totally destroyed, and the contents of the
vat may be thrown away. No further addition of woad is required after the intro-
duction of the quantity taken in first setting the vat, the fermentation being kept up
b^ adding daily about 4 lbs. of bran, together with 1 quart or 3 pints of lime. In-
digo is also added daily for about three or four months. The vat is then used for the
purpose of dyeing light shades, until ihe indigo contained in it is quite exhausted, and
its contents an then thrown away.
Woollen cloth before being dyed is boiled in water for one hour, then passed im-
mediately into cold water. If it be suffered to lie in heaps immediately after being
boiled, it undergoes some change, which renders it afterwards incapable of taking up
colour in the vat When a purple bloom is required on the cloth, it is dyed with cud-
bear to a light purple shade before being dipped. In dyeing, the cloth is placed on a
network of rope attached to an iron ring, which is suspended by four iron chains at
INK. 519
a depth of about 3 feet beneath the suiface of the liquor. The doth Lb stirred about
ia the liquor by means of hooks for about 20 or 30 minutes. It is tiien taken out
and well wrung. It now appears green, but on being unfolded and exposed to the air
rapidly becomes blue. When the rat contains an excess of lime the cloth has a
dark green colour when taken out It is then passed through hot water and dipped
again, if a darker shade is required. When woollen flocks are to be dyed, they are
placed in a net made of cord, which is suspended by hooks at the side of the Tat.
They are then transferred to a stronger net and wrung out by sereral men. In dye-
ing flocks a more actiTC fermentation of the vat is required ^an with cloth.
The process of dyeing by means of sulphate of indigo is quite different from indigo
dyeing in the rat This process was discovered by Barth, at Grossenhayn in Saxony,
about the year 1740, and the colour produced by it is hence called Stueon blue. The
method of purifying sulphate of indigo, by immersing wool in the solution of crude
indigo in oil of yttriol, previously diluted with water, has been described above. The
process of making sulphate of indigo or extract of indigo, as it is called, as now prac-
tised on the large scale, is as follows : — 1 lb. of indigo is mixed with from 8 to 9 lbs.
of oil of vitriol, and the mixture is left to stand for some hours in a room, the tem-
perature of which is 90^ Fahr. It is then diluted with water, and filtered through
paper. There is left on the filter a dirty olive-coloured residue, which is used for
some purposes by woollen dyers. By now adding common salt to the liquid, a blue
precipitate of sulphate of indigo is produced, which is collected on a filter, and
washed with a solution of salt in order to remove the excess of acid. No neutra-
lisation with alkali is required when this plan is pursued. The blue produced on
wool and silk by means of sulphate of indigo is very fugitive, and is now seldom
required, its place having been in a great measure taken by the blue from prussiate of
potash. The chief use of sulphate of indigo is for dyeing compound colours,- such as
green, olive, grey, &c
INGRAIN. Wools, &c., are said to be dyed ingrain when they are subjected to
that process before manufacture,
INK. (Encre, Fr., TVnte, Germ.)
Wriiimg Ink may be and is prepared in many different ways ; but it is essentially a
tanno-gallate of iron.
Nutgalls* sulphate of iron, and gum are the only substances truly useful in the
preparation of ordinary ink ; the other things, often added, merely modify the shade
and considerably diminish the cost to the manufacturer upon the great scale. Many
of these inks contain little gallic acid or tannin, and are therefore of inferior quality.
To make 12 gallons of ink we may take, 12 pounds of nutgalls, 5 pounds of green
sulphate of iron, 5 pounds of gum Senegal, 12 gallons of water. The bruised
nutgalls are to be put into a cylindrical copper, of a depth equal to its diameter, and
boiled during three hours, with three-fourths of the above quantity of water, taking
care to add fresh water to replace what is lost by evaporation. The decoction is to
be emptied into a tub, allowed to settle, and the clear liquid being drawn off, the lees
are to be drained. Some recommend the addition of a little bullock's blood, or white
of egg, to remove a part of the tannin. But this abstraction tends to lessen the
product, and will seldom be practised by the manufacturer intent upon a large return
for his capital. The gum is to be dissolved in a small quantity of hot water, and the
mucilage thus formed, being filtered, is added to the clear decoction. The sulphate
of iron must likewise be separately dissolved, and well mixed with Uie above. The
colour darkens by degrees, m consequence of the peroxidisement of the iron, on ex-
posing the ink to the action of the air. But ink affords a more durable writing when
nsed in the pale state, because its particles are then finer and penetrate the paper more
intimately. When ink consists chiefly of tannate of peroxide of iron, however black,
it is merely superficial, and is easily erased or effaced. Therefore, whenever the
liquid made by the above recipe has acquired a moderately deep tint, it should be
drawn off clear into bottles and well corked up. Some ink makers allow it to mould
a little in the casks before bottling, and suppose that it will thereby be not so liable to
become mouldy in the bottles.
From the comparatively high price of gallnuts ; sumach, logwood, and even oak
bark are too frequently substituted, to a considerable degree, in the maau&ctnre of
ink ; but always injuriously.
The ink made by the recipe given above, is much more rich and powerful than
many of the inks commonly sold. To bring to their standard a half more water may
safely be added, or even twenty gallons of tolerable ink may be made ftom that weight
of materials, as I have ascertained.
Sumach and logwood admit of only about one half of the copperas that galls will
take to bring out the maximum amount of black dye.
LL 4
520 INK.
Lewifl, who made exact experiments on inks, assigned the proportion of dunee paiti
of galls to one of sulphate of iron, which, with average galls, will answor Teiy well ;
hnt good galls will admit of more copperas.
Bed inS, — This ink may be made by infusing for three or four days in weak
Tlnegar, Brazil wood chipped into small pieces ; the infosion may then be boiled
upon the wood for an hour, strained and thickened slightly with gam Arabic and
sugar. A little alnm improTCS the colour. A decoction of cochineal with a little
water of ammonia, forms a more beautiful red ink, but it is fngitiye. An extern-
poraneous red ink of the same kind msj be made by dissolying carmine in weak
water of ammonia, and adding a little mucilage.
Blue ink. — Mr. Stephens^s patent blue ink is made by dissolving Prossian bloe in
a solution of oxalic acid. The blue should be washed in dilate muriatic acid. !£
Hamung has given the following as the best formula for blue ink : —
Mix 4 parts of perchloride of iron in solution with 750 parts of water, then add
4 parts of cyanide of potassium dissolved in a little water ; collect the precipitate
formed, wash it with several additions of water, allow it to drain until it weighs aboot
200 parts ; add to this one part of oxalic acid, and promote solution of the cyanide
by shaking the bottle containing the mixture. The addition of gum and sogar is
useless, and even appears to exercise a prejudicial effect on the beauty of the ink. It
may be kept without any addition for a long time.
China or Indian ink, — Proust says, that lamp black purified by potash lye, when
mixed with a solution of glue and dried, formed an ink which was preferred by
artists to that of China. M. Merim^e, in his interesting treatise entitled De Cm
Peinture a VHude^ says, that the Chinese do not use glue in the fabrication of their
ink ; but that they add vegetable juices, which render it more brilliant and more
indelible upon paper. When the best lamp black is levigated with the purest gelatine
or solution of ^lue, it forms no doubt an ink of a good colour, but wants the shining
fracture, and is not so permanent on paper as good China ink, and it stiffens in cold
weather into a tremulous jelly. Glue may be deprived of the gelatinising property
by boiling it for a long time, or subjecting it to a high heat in a Papin's digMter ;
but as ammonia is apt to be generated in this way, M. Merimce recommends starch
gum made by sulphuric acid to be used in preference to glue. He gives, however,
the following directions for preparing this ink with glue. Into a solution of glue he
pours a concentrated solution of gall-nuts, which occasions an elastic reainons-looking
precipitate. He washes this matter with hot water, and dissolves it in a spars sola-
tion of clarified glue. He filters anew, and concentrates it to the proper degree for
being incoporated with the purified lamp black. The astringent principle in vege-
tables does not precipitate gelatine when its acid is saturated, as is done by boiling the
nut-galls with limewater or magnesia. The first mode of making the ink is to be
preferred. The lamp black is said to be made in China, by collectiug the smoke of
the oil of sesame. A little camphor (about two per cent ) has been detected in the
ink of China, and is supposed to improve it. Infusion of galls renders the ink per-
manent on paper.
Indelible ink, — A very good ink, capable of resisting chlorine, oxalic acid, and ab-
lution with a hair pencil or sponge, may be made by mixing some of the ink made by
the preceding prescription, with a little genuine China ink. It writes welL Many
other formulas have been given for indelible inks, but they are all inferior in sim-
plicity and usefulness to the one now prescribed. Solution of nitrate of silver
thickened with gam, and written with upon linen or cotton doth, previously imbued
with a solution of soda, and dried, is the ordinary permanent ink of the shops. Before
the cloths are washed the writing should be exposed to the sunbeam, or to bright day*
light, which blackens and fixes the oxide of silver. It is easily discharged by chlorine
and ammonia.
A good permanent ink may be made by mixing a strong solution of chloride of
platinum, with a little potash, sugar, and gum to diicken. The writing made there-
with should be passed over with a hot smoothing iron to fix it
Another indelible ink may be prepared by addinp^ lamp black and indigo to a so-
lution of the gluten of wheat in acetic acid. This ink is of a beautiful black coloar,
at the same time cheap, and cannot be removed by water, chlorine, or dilate acids.
M. Herberger gives the following directions for its preparation : — Wheat gluten is
carefully freed from the starch, and then dissolved in a little weak acetic acid ; the
liquid is now mixed with so much rain water that the solution has about the strength
of wine vinegar, that is, neutralises ^th of its weight of carbonate of soda. 10 grains
of the best liunp black and 3 grains of indigo, are mixed with 4 ounces of the solution
of gluten, and a little oil of cloves added. This ink may be employed for mailing
linen, as it does not resist mechanical force.
Indelible ink of Dr. Traill is essentially the same as the above.
IODINE. 521
French indeltUe ink is made of Indian ink difliised ihroagh dilate mnriatic acid
for writing with qniUs, and through weak potash lye for writing with steel pens.
/mA, Printimg, — This is essentially a combination of lamp black, — finely divided
carbon, — with oiL Mr. Underwood, in a commanication made by him to the Society
of Arts, well defines the necessary qualifications of a good ink.
IsL It mnst distribute freely and easily, and work sharp and clean.
2nd. It most not hare too mach tenacity for the type, bat have a much greater
aflbiity for the paper, and so come off fireely upon it.
drd. It most drf almost immediately on the paper, bat not dry at all on the type or
rollers; this is a great desideratum, especially for newspapers.
4th. It should be literally proof against the effects of time and chemical reagents,
and never change colour.
Great attention must be paid to the quality of the linseed oil employed, and even
the character of seed from which the oil is obtained should not be neglected.
Tlie linseed oil is clarified from ihe fatty matters, and the pure oil is boiled wiih
great care at a carefully regulated temperature ; and during the boiling, the best pale
yellow soap is added to give it consistency, and the required dryers are also now
mixed with it The best black is that obtained from the smoke of naphtha, the com-
bustion being carefully regulated. This black is ground up carefully with the
drying oil, which has assumed somewhat of the character of a varnish, and the ink is
complete.
Goid and nher inks are prepared by grinding upon a porphyry slab with a muUer
gold or silver leaves, with white honey, until they are reduced to the finest possible
■tate of division. The honey is thoroughly washed from the powdered metels, and
these are mixed up with gum water.
INKING ROLLER. See PiUNTiNa
IODINE {lod, Fr.; lod. Germ.) is one of the elementary substances; it was
accidentally discovered in 1812 by M. Courtois, a manufacturer of saltpetre at Paris.
He found, that in the manufacture of soda from the ashes of seaweeds, the metallic
vessels, in which the processes were conducted, became much corroded ; and in
searchhig for the cause of the corrosion, he discovered this now important substance.
It was first described by Clement in 1813, but was afterwards more fully investigated
by Davy and Gay-Lussac
Gay-Lussao and Clement at first looked upon hydriodic acid as hydrochloric acid,
until Sir H. Davy suggested the idea of its b^ing a new and peculiar acid, and iodine
as a substance analogous in its chemical relations to chlorine.
It was named iodine fh>m the Greek word M^t, violet-coloured, on account of the
colour of its vapour.
Iodine exists in many mineral waters in combination with potassium and sodium.
In the mineral kingdom, iodine has been found in one or two rare ores, as in a
mineral brought from Mexico, in which it existed in combination with silver, and also
in one firom Silesia in combination with zinc
It exists also in very small quantities in sea water, firom which it is extracted by
many sea- weeds, which act therefore as concentrators of iodine ; these sea-weeds when
dried and ignited yield an ash, technically called kelp, from which all the soda of
commerce was previously obtained, but the chief value of the kelp now is on account
of the iodine whi<di it yields. The following is the process most generally adopted for
the extraction of the iodine ftt>m the sea-weeds.
The sun-dried sea-weed is incinerated in shallow excavations at a low temperature,
for if the temperature was allowed to rise too high a considerable quantity of iodide of
sodium would be lost by volatilisation. The half-fused ash or kelp which remains is
Itfoken into fragments, and treated with boiling water, which dissolves about one half
of the ash.
The liquid thus obtained is evaporated, when on cooling the moreerystallisable salts
separate, viz. sulphate and carbonate of soda, with some chloride of potassium. The
mother liquor still contains the iodide of sodium, sulphide of sodium, sulphide and
some carbonate of soda. This liquor is then mixed with about one-eighth of its bulk
of sulphuric acid, and allowed to stand for twenty-four hours ; carbonic and sulphurous
acid, and sulphuretted hydrogen gases escape, a firesh quantity of sulphate of soda
crystallising out, mixed with a precipitate of sulphur.
The supernatant acid liquor is then transferred to a leaden still, to which is adapted
a double tubulated leaden head luted on with pipe-clay ; it is then heated to 140^ F.,
when binoxide of manganese is added.
The temperature may be gently raised to 212° F., but not higher, as some chlo-
rine would come over, and combme with some of the iodine, forming chloride of
iodine.
The iodine is condensed in spherical glass condensers, each having two mouths
522 IRON.
opposite to each other, and inserted the one into the other, the end one heing fitted to
the neck of the leaden head.
The iodine is purified hy resublimation.
The following formola represents the reaction :
Iodide of Oxide of Sulphuric Sulphate of Sulphate of Iodine. Water.
Sodium. Manganeie. Acid. Soda. Hanganeee.
Nal + MnO* + 2HSO* = NaSO* + MnSO* + I + 2HO
The British iodine is ezclasivelj mannfactured at Glasgow, from the kelp of the
west coast of Ireland, and the western islands of Scotland.
Iodine is a crjstallisable solid, its primary form being a rhombic octohedron. It is
however usually met with in micaceous, soft, friable scales, having a greyish-blaek
colour, a metallic lustre, and an acrid hot taste. Even at ordinary temperatnres, and
more especially when moist, it is sensibly volatile, emitting an odour like that of
chlorine, only much weaker. ^
At 225^ F. it fuses, and at 347^ F. boils, and is converted into a magnificent violet
vapour. It may nevertheless be distilled, in the presence of steam, at a temperature
of 212^, as is seen in the process of manufacture.
Iodine, in the solid state, has a specific gravity of 4*947, the specific gravity of die
vapour being, according to Dumas, 8*716. Iodine is only very slightly soluble in
water, it requiring 7000 parts of water to dissolve it ; even then it imparts a yellow
colour to the solution, and is used in that state as a test for starch, with which it forms
a beautiful blue compound, which is, however, destroyed by heat
Alcohol and ether dissolve it 'more readily ; but the most powerful solvents of
iodine are the solutions of the iodides. Iodine stains the skin, and most arganie
substances, of a brown colour ; it attacks the metals rapidly ; iron or zinc being
readily dissolved by it if placed in water with it, an iodide of the metal being
formed.
All the compounds of iodine with the metals and with hydrogen are deeomposed
by chlorine, and even by bromine, iodine being set free. Advantage is taken of this
&ct in detecting the presence of iodine. If the iodine exists in combination with a
metal, or as hydriodic acid, its solution will not form the characteristic intense blue
compound with starch, but on the addition of a little chlorine, or solntion of bleaching
powder, the iodine is set free and forms the blue compound with the starch. If how-
ever the iodine exists as iodic acid, it will not act npon starch until reduced by some
reducing agent, as sulphurous acid. In using the chlorine care must be taken not to
use too much, as it would unite with the iodine and prevent it acting on the starch.
Iodine is used to a considerable extent in medicine ; when taken in large doses it is
an irritant poison, but in small doses it is a most valuable medicine, particularly in
glandular swellings, and in certain forms of goitre. It is also much used in photo-
graphy. The chemical symbol for iodine is I; its equivalent number 126*88; and
the combining volume of its vapour 2. — H. K. B.
IRIDIUM. A rare white metal, found in connection with platinnm and o«mhmL
The natural combination of iridium and osmium is called the ** native alloy," and on
account of its hardness is used to point metallic pens. See Native Aixot.
IRISH MOSS. See ALOiE.
IRON {Fer, Fr. ; Euen, Germ.) is a metal of a bluish-grey colour, and a dull fibrous
fracture, but it is capable of acquiring a brilliant surface by polishing. Its specific
gravity is 7 '78. It is the most tenacious of metals, and the hardest of all those which
are malleable and ductile. It is singularly susceptible of the magnetic virtue, hot in
its pure state soon loses it. When rubbed it has a slight smell, and it imparts to the
tongue a peculiar astringent taste, called chalybeate. In a moist atmosphere iron
speedily oxidises, and becomes covered with a brown coating called rust
Every person knows the manifold uses of this truly precious metal ; it is capable of
being cast in moulds of any form ; of being drawn out into wires of any desired strength
or fineness ; of being extended into plates or sheets ; of being bent in every direction ;
of being sharpened, hardened, and softened at pleasure. Iron accommodates itself to all
our wants, our desires, and even our caprices ; it is equally serviceable to the v^ the
sciences, to agriculture, and war ; the same ore furnishes the sword, the ploughshare,
the scythe, the pruning hook, the needle, the graver, the spring of a watch or of a
carriage, the chisel, the chain, the anchor, the compass, the cannon, and the bomb.
It is a medicine of much virtue, and the only metal friendly to the human frame.
The ores of iron are scattered over the crust of the globe with a beneficent profusion
proportioned to the utility of the metal ; they are found under every latitude, and every
zone ; in every mineral formation, and are disseminated in every soil. Considered in
a purely mineralogical point of view, without reference to their importance for reduc-
tion, they may be reckoned to be 19 in number; namely, 1, native iron of three
IRON.
523
kinds : pme, niokeliferoiu, and steellj; 2, arsenical iron ; 3, yellow tulphoret of iron j
4, white snlphnret of iron ; 5, magnetic sulphnret of iron ; 6, black oxide of iron,
either the loadstone, or susceptible of magnetism, and titaniferous ; 7, compact ftr
oliffUte, specular iron ore, aa of Elba, and scaly /er oUgiste; 8, hematite, affording a
red powder ; 9, hematite or hydrate of iron, affording a yellow powder, of which
there are sevenl Tarieties ; 10, pitchy iron ore ; 11, siliceo-caloareoas iron, or yenite ;
12, sparry carbonate of iron, and the compact clay iron-stone of the coal formation ;
13, phosphate of iron; 14, sulphate of iron, native copperas; 15, chromate of iron ;
16, arseniate of iron ; 17, mnnate of iron ; 18, oxalate of iron ; 19, titanate of iron.
Among all these different species, ten are worked by the miner, either for the sake
of the iron which they contain ; for use in their native state ; or for extracting some
principles from them advantageous to the arts and manufactures ; such are arsenical
iron, sulphate of iron, sulphuret of iron, and ehromate of iron.
Native Ibon.
A. Telluric iron, nearly pure. — This species, which is very rare, occurs in small
grains and plates, or massive and disseminated. It is malleable and ductile, more so
than ordinary malleable iron, and ranges in specific gravity between 7 and 7'8. It
contains carbon, and occasionally some other metal, but not nickel A specimen from
Gross Camsdorf, in Tfauringia, analysed by Klaprotfa, yielded 92*5 iron, 6 lead, and 1*5
copper : its structure was foliated and its texture crystcdline. Native iron was found by
Schreiber, in a vein at Oule, near Allemont in Dauphin^. A specimen containing 9 1 -8
iron and 7*0 carbon {Shepard), was observed at Canaan in Connecticut, in a vein two
inches broad lyiug in mica slate ; another specimen was found in sandstone at Penn
Yan, in New York. John states that it is mixed with the platina grains from South
America, and more recently M. Molnar has affirmed that he has found native iron in
the gold sands at Olahpian. It is also stated that native iron, with 6 per cent of silica,
and a little sulphur, hu been found with galena in the veins at Leadhills, and Mossier
has found volcanic iron in lava at Graveneire in Auverg^e. It had a steel grey or
ailver white colour, foliated texture, and hackly fracture. These instances would
seem to prove the actual existence of native iron, which was for a long time disputed.
B. Native nickdi/eroua or meteoric iron — This species is distinguished from the
last by containing nickd and sometimes coUUt, It is very malleable, often cellular,
but sometimes compact, and in parallel plates which pass into rhomboids or octahe-
drons. When polished and etch^ with acids, it exhibits linear and an^^r markiogs,
or WidmannstaU't figures, as ihej have been termed, and from which an impression may
he printed on paper. A very great number of undoubted meteorites have been
described and analysed. The following table from Nicolas Manual qf Mineralogy
exhibito the composition of some of the most remarkable.
1
2
3
4
5
6
7
8
9
10
11
Iron.
Nickel.
Cobalt.
Copper.
Hanga-
neae.
Hagne.
slum.
Sulphur.
Cblo.
rina.
Insol.
Hatter.
Toul.
93*78
88*04
88*23
89*78
85*61
90-88
66-56
90-24
83*57
92*58
81-8
3*81
10*73
8-52
8*89
12*27
8-45
24-71
9 76
12-67
5-71
11*9
0*21
0*46
0*76
0*67
0*89
0*67
1*0
• •
0*07*
m m
0002
* •
* to
m •
trace §
0*13
trace
m »
8*24 1
02
0*05
0-28
trace
trace
4*00
m m
6*1
• *
1*48
m m
0-9 It
m •
2*20
0*48
2*21
•■ to
to to
to to
1-40
100
100
100
99*34
98-77
100
99*99
100
99*54
99-69
100
* With till -fO-iM carbon. f With chromium. t +2*30 sulphuret of iron. ^ With arsenic.
The insoluble matter in the above contains in 100 parts —
In No.
iron.
Nickel.
Phosphorus.
snica.
Carbon.
Hagnetium.
Total.
1
2
3
10
65-99
48-67
•68-11
441
1501
18-33
17*72
24*50
1402
1847
1417
11-4
2*04
? 100
1*42
to *
9*66
98*4
95*13
100*0
90 0
624 IRON.
The aboTe aiudyMS are of : — 1. A mass of 103 lbs. weight, which fell at BiAnmititSv
in Bohemia, in 1829. 2. A mass weighing 1,600 lbs., found in 1748, near Kna-
nojarsk, on the Yenisei 3. The so-called ** Verwilnschte Borggraf," ftom Elbogon
in Bohemia, which weighed 191 lbs. 4. A mass of 71 Vienna pounds weight, which
fell at Hraschina, near A^ram, in Croatia, on 26th May, 1751. 5. A mass in the
Ebierlaem Museum, found m 1793, on the plain between the Great Fish River and Graf
Rejnet, in the Cape Colony, originally weighing 300 lbs. 6. Found at Lenarto, in
Hungary, original weight 19411m. 7- From Clairbome in Alabama. 8. From FotosL
9. Is a more recent analysis of the same. 10. From Lockport in North America.
1 1. From Bitburg, near Treves, which weighed above 3,300 lbs.
According to Shepard (Silliman*s American Journal), the fiill of meteoric
stones is confined principally to two zones. The one belonging to America lies
between 33° and 44° 2«. lat, and is about 25° in length. Its direction is more or
less from N. £. to S. W., following the general line of the Atlantic coasts Of all the
occurrences of this phenomenon during the last 50 years, 92 '8 per cent have taken
place within these limits, and mostly in the neighbourhood of the sea. The zone of
the eastern continent, with the exception that it extends 10° further to the north, is
bounded by the same degrees of latitude, and follows a similar north-east direcdon ;
but it has more than twice the length of the American zone. Of the observed falls of
aerolites, 90-9 per cent occurred within this area, and were also concentrated in that
half of the zone which extends along the Atlantic.
The most remarkable masses of meteoric iron are, that found by Don Rabin de
Celis, in Tucuman in South America in 1783, weighing 300 cwts. ; that discovered
in 1784 on Uie Riacho de Bendego in Brazil, estimated to measure 32 cubic feet, and
to weigh 1 7,300 lbs. ; and that on the Red River in Louisiana, weighing above 3000 lbs.,
and presenting distinct octahedral crystals.
c. 1. Native Steel-Iron. — This substance has all the characters of cast steel; it
occurs in a kind of small button ingot, with a finely striated sur&ce and a fracture ex-
ceedingly fine grained. It is hardly to be touched by the file, and will scarcely flatt^i
under the hammer. M. Mossier found this native steel at the village of Booiche,
near Nery, department of the Allier, in a spot where there had existed a seam of
burning coal. A mass of 16 lbs. 6 oz. of native steel was discovered in that place,
besides a great many small globules.
2. Mispickd; Dipriamatic Arsenical iron ; Arsenikkies. This mineral is found
massive, granular, or columnar, and disseminated. It is brittle, with an nneven
fracture ; colour, silver white, or almost steel gjey, with a greyish or yellowish tarnish;
specific gravity 6—6*2. When heated in a closed tube it yields first a red, then
a brown sublimate of sulphuret of arsenic, and then metallic arsenic Some varieties
contain silver or gold, in others part of the iron is replaced by cobalt Viewing it as
a double sulphide and arsenide of iron, its formula would be FeS" + FeAs, which
requires iron, 33'5; sulphur, 19*9; arsenic, 46*6. A specimen analysed by Plattner
gave, iron, 34*46 ; sulphur, 20*07 ; arsenic, 45*46. Mispickel is common in the mines
of Freiberg in Saxony, and in the tin mines of Bohemia, Silesia, and in ComwalL it
is of no use as an ore of iron, but it is occasionally worked for the silver it contains,
and as an ore of arsenic.
3. Yellow sulphvret of iron; Prismatic iron pyrites; or ilforeewfe. — The bronae or
brass yellow colour enables us to recognise this mineral At the blowpipe it gives
off its sulphur, and is converted into a ^obule attractable by ^e magnet It is brittle,
with a conchoidal or uneven fracture. Sp. gr. 4*9 — 5*1. It is soluble in nitric acid
with deposition of sulphur, but is scarcely affected by hydrochloric acid. It is a
bisulphide of iron (FeS^, 46*7 iron, 53*3 sulphur. Hatchett found 47*3 iron, 527
sulphur ; and Berzelius, 46*08 iron, and 53*92 sulphur. It is very liable to decom-
position, being sometimes oxidised into sulphate of iron, and sometimes into hydrated
peroxide, the sulphur becoming altogether eliminated. It is one of the most common
minerals in rocks of all ages and daraes ; it occasionally contains both gold and silver.
It is used for the manufacture of sulphur, sulphuric add, and alum, but as aa ore of
iron it has no commercial value.
4. Hexahedral iron pyrites or pyrene, — This mineral is distinguishable from the
former only b^ its colour and form of crystallisation, and was hence till lately eon-
founded with It by mineralogists. Its sur&ce is often radiated.
5. Magnetic iron pyrites, pyrrhotine, the magnetkies of the Germans This mineral
occurs chiefly in the igneous and crystalline, or older stratified rocks, in veins with
various ores. Its colour is between bronze yellow and copper red, with a pinchbeck-
brown tarnish, streak greyish-black, and more or less magnetised. When heated in
an open tube it yields sulphurous fumes, but no sublimation ; before the blowpipe on
charcoal in the "educing flame it fuses to a black strongly magnetic globule ; it is
lEON. 525
soluble in hydrochloric acid, erolving sulphuretted hydrogen and depositing solphur.
According to Q. Rose, this mineral idways contains a larger quantity of sulphur
than corresponds with the simple stdphide FeS ; and he idopts for it the fiirmula
5Fe8 -¥ Fe*S*; corresponding with 60*44 iron, and 39*56 sulphur, which agrees very
closely with the analyses ^t ha^e been made by Stromeyer, H. Rose, and others.
6. Biack oxide of iron ; Magnetite, or native loadstone, or octahedral iron ore. — This
Tery rich and yaluable ore occurs especially in igneous or metamorphie rocks, either
in distinct crystals, or, as in many basalts, disseminated through the mass, when it
frequently imparts magnetic properties to the rocks, especially to greenstone, serpentine
or basalt. It also forms beds in gneiss, in chlorite, mica, hornblende, and clayslates,
in marble, greenstone, and other rocks, but seldom appears in Tcins. The largest
known masses occur in the northern parts of the globe, in Scandinayia, Lapland,
Siberia, and North America. Less eztensiye masses occur in the Hars, in Saxony,
Bohemia, Silesia, and Styria ; and in Southern Europe, in £lba and Spain. Magnetite is
the most important ore of iron inNorway, Sweden, and Russia. The Dtunnemora mines
in Sweden, wrought in an open quarry 150 feet broad, and 500 feet deep, furnish the
fine Oeregrund iron, largely imported into England for the manufkcture of steeL
Some highly magnetic yarieties, especially ftom Siberia and the Harz, form natural
magnets, possessing distinct polarity. Others become polar only after contact with
magnets of sufficient power. Magnetic iron ore fuses with extreme difficulty: it is
not acted upon by nitric acid, but when powdered is soluble in hydrochloric; its
specific grayity yaries from 4*24 to 5*4. The chemical formula of pure magnetite is
FeO,FeH)*, corresponding to 31*03 of protoxide, and 68*77 of peroxide of iron, or
at 72*40 iron, and 27*60 oxygen, which agrees closely with the analyses of Berselina,
Kobell, and Karsten.
Two specimens of magnetic iron ore firom Cornwall had the following compositions
(I>r. JVbad):—
Water - - -
.
_
.
2-50
.
- 3*20
Protoxide of iron -
-
.
.
20*00
.
. 13*00
Peroxide of iron
.
.
.
44-40
.
- 66*60
Oxide of manganese
.
.
-
•16
•
•56
Alumina
•■
.
.
5*20
.
- 3*60
Lime ...
.
.
.
0-60
.
- 0-56
Magnesia
-
-
.
100
.
. 1*52
Sulphuric acid
.
.
-
0*04
.
- 0-04
Phosphoric acid
.
•
.
0*50
.
- 0*57
Insoluble residue
-
.
M
24*20
-
- 9*40
99*60 98*95
7. Hamntite ; Specular iron ; Fer oligiete ; Rhombohedral iron ore, — This ore has a
metallic lustre ; colour, iron black to steel grey, but often tarnished ; the light trans-
mitted through the thin edges of its crystals appears of a beautiful red coloor. Its
powder is always of a well marked brown red hue, passing into cherry red, which
distinguishes it from the black oxide ore ; its fracture is conchoidal or uneyen ; it is
brittle, and its specific grayity is 5*2. Its chemical composition is Fe'O', 70 03 iron,
and 29*97 oxygen, but it sometimes contains oxide of titanium, or titanic acid, chrome,
or silica ; in the reducing flame of the blowpipe, it becomes black and magnetic.
Hsematite is one of the most abundant ores of iron. The specular yariety occurs
chiefly in the older crystalline rocks in large beds or yeins. The mines of the island
of Elba celebrated from antiquity, still furnish the finest crystals, which occur in
druses of the massiye yariety along with pyrites and quartz : fine crystals are like-
wise produced from St Gotthardt, Framont, in the Yosges mountains, the Harz,
Altenberg in Sweden, and from Katherinenburg in the Ural. Beautifiil specimens of
the micaceous yariety occur at Zorge and other parts of the Harz, at Tincroft in
Cornwall, Tayistock in Deyonshire, in Wales, Cumberland, and Perthshire. It
also occurs in yolcanic rocks, as in AuTcrgne, on Vesuyius, JEtna, and the Lipari
islands, especially Stromboli, where some fine crystals, three inches broad and four
long, have been procured.
8. Bed hamatites. — These ores are found in the greatest abundance in the moun.
tain or carboniferous limestone formations. The most abundant deposits in this
country are those of Lancashire, Cumberland, and the Forest of Dean, where the ore
exists in almost unlimited quantity. In the latter locality they were worked most
extensiyely at a yery early date, and though as a class they are not rich, yet ftom
the great masses in which the ore is found, its cost of production is very low, about
2«. to 3s; per ton (Blackwdl), The iron made from the Forest of Dean ore, is of
526
IRON.
the quality called rerf-sAort, ani is especially celebrated fbr the manufsctore of tin
plates. This ore is raised extensively for shipment to the iron works of Soatli
Wales.
The Tarying quality of the Forest of Dean ores is shown in the followinir analyses.
{Dr, Noal)
Water
Carb. lime - - - -
Carb. magnesia - - -
I.
II.
III.
IV.
V. 1
3-16
27-00
16-00
6-80
25-50
18-30
2-90
39-60
25-00
2-11
14-10
17-10
r-70
18-40
18-80
•20
36-62
traces
030
18-00
V/XlCIc maUgiUlcoC * a •
Peroxide of iron - - -
Alumina - - - - -
Sulphuric acid - - - -
Phosphoric acid . . -
Insoluble residue . - .
40*80
600
traces
traces
8-84
38-10
3-60
traces
traces
8-70
29-00
traces
traces
3*50
69*70
1-89
traces
0-20
5 10
100-80
100-00
100-00
10046
lOOtfi
The hsmatite of Whitehaven occurs in the carboniferous limestone near the oat-
crop or surfiice edge of the slaty rocks upon which that formation rests. The greater
part of the excavations from which it is extracted are subterraneous, and so extensive
IS often the mass of iron ore in which the workings are carried on, that it is difficult in
such situations to obtain a clear idea of the nature of this important deposit ( War-
rington Smyth.) 67,248 tons of the haematite of the Whitehaven district is smelted
on the spot, at the Cleator Moor and Workington works, and 264,296 tons are sent
into the iron making districts. In the year 1858, 436,ri95 tons were sent away by sea
and railway from Uie Ulverstone district, and no less than 690,840 tons of hema-
tite were exported during 1858 (Hunt), for the supply of Staffordshire, South Wales,
and other districts from these two localities. Considering its quality, it brings bat
a low price, vis. from lU. 6dl to 13«. Sd, per ton.
The following analyses of some carefully selected samples of the hematite of the
carboniferous limestone are bv Messrs. Dick and Spiller. (Memoirs of the Gtdogical
Survey of Great Britain, The Iron Ores of Great Britain, Part L)
Peroxide of iron -
l^rotoxide of manganese
Alumina . - -
Lime . - .
Magnesia - - -
Phosphoric acid •
Sulphuric acid -
Bisulphide of iron
Water, hygroscopic -
„ combined
Insoluble residue
Carbonic acid
Cleaton
Moor.
9516
0-24
007
* «
trace
trace
trace
5-68
101-16
Cleat on
Moor.
UWer-
ttone.
90-36
0-10
0-37
0-71
0-06
trace
trace
0-06
8-5 &
86-50
0-21
2-77
1-46
trace
0-11
6*55
2-96
100-20
100-56
Llndall
Moor, new
UWerttooe.
94-23
023
0-51
005
trace
trace
0-09
0-03
0-39
017
5*18
100-88
The carboniferous limestones of Derbyshire and Somersetshire also contain veins
and deposits of hematite, though of a quality not equal to those of Lancashire ; the
same ore is also met with in the Devonian series of Devon, West Somerset, and
Cornwall.
9. Brown HamatiteM ; Brown oxide of iron ; Hydrous oxide of iron. — This species
affords always a yellow powder, without any shade of red, which passes sometimes
into the bistre brown, or velvet black. At the blowpipe it becomes biown, and very
attractable by the magnet ; but after calcination and cooling the ore yields a red
IRON.
527
powder, ▼hich stains paper nearlj as red as the hnmatite does, and wliicli is much
employed in polishing metals. AU the yellow or brown oxides contain a large pro*
porti<m of water in chemical combination. There are several varieties, which assume
globolar, reniform, stalaetitic, and frnticose shapes. In many countries this is one
of the most plentlfiil and valoable ores of iron ; in the oolitic form it supplies by &r
the greater nnmber of the French iron works. In that state it is found in Mor«
mandjr. Berry, Bnrgnndy, Lorraine, and many other places. It is this ore which
exclusiTely supplies the Belgian iron works. It is found in this country in considerable
quantities at Alston Moor and Durham, but is only used to a limited extent, on
account of its association with lead and zinc
The iron which the brown hematites produce does not at present stand high ; it
possesses fluidity, but has a great tendency to cold shortness, and is most suitable for
foundry purposes.^ — BlackwdL
The chemical composition of pure brown hematite is 2FeH>' + 3HO ; 85*6 per-
oxide of iron (» 60 iron) and 14*4 water. Yellow ochre (gelbeisenstein) is con-
ndered by Hausmann to be a distinct species; a specimen analysed by him contained
81*6 peroxide of iron, and 18*4 water, corresponding to the formula FeH)* + 2 HO.
Bog iron ore is also a hydrated oxide of iron; it occurs chiefly in bogs, meadows,
and lakes, especially in the level districts of Northern Germany and Sweden. In
Britain it is most abundant in the northern and western islands of Scotland. It is
generally very impure, sometimes containing as much as 10 per cent, of phosphoric
acid, which renders it all but useless fbr iron making purposes. The atites, or eagle
stones, are also a variety of this ore ; on breaking the ImUs so named, they are ob-
served to be composed of concentric coats, the outside ones being very hard, but the
interior becoming progressively softer towards the centre, which is usuaUy earthy,
and of a bright yellow colour, sometimeSj however, the centre is quite empty, or con-
tains only a few drops of water. JEtites occur in abundance, often even in con-
tinuous beds, in secondary mountains, and in certain argillaceous strata; when smelted
they yield a good iron.
Some of the brown hematites contain a large percentage of manganese. Their
general composition Is illustrated in the following analyses (Jh, Noad),
Water - - -
Oxide of manganese
Lime - - .
Magnesia
Alumina
Peroxide of iron -
Sulphuric acid
Phosphoric acid
Insoluble residue -
I.
II.
IlL
IV.
12*85
12*80
12-40
13-20
8*08
9*60
8-80
11-20
1-72
MO
1*20
108
1-20
•92
1-20
1-04
68*57
68-45
67*77
66-98
Oil
0*11
010
0*096
roi
1*02
1*12
1*054
1200
9-50
8-80
11*200
100-54
101-20
99*79
100-85
10. Pitchy hydrate of iron ; Petticite; Eisensinter, — This mineral occurs in many
old mines, especially those near Freiberg ; and also at Schneeberg in Saxony, Pleiss
In Silesia, and Bleistadt in Bohemia. It is probably a product of the decomposition
of mispickel: its composition, according to the analysis by Stromeyer being F^O',As
0*+ F^)',SO'+ 15HO =m 35 peroxide of iron, 26 arsenic acid, 9 sulphuric acid, and
30 water. According to Freidehen^ it is first fluid, and gradually separates in a solid
form. In external characters it agrees with Diadochitef which is Fe'0',2P0* +
4Fe'0',S0' + 32 HO, according to Gmelin from Plattner's analysis, viz. peroxide of
iron, 36*69 ; phosphoric acid, 14*81 ; sulphuric acid, 15'15 ; water, 30*35.
1 1. Yenite or Liimite ; Hisingerite or thravlite ; Nontronite : Pinguite ; and Chloropal,
are rather rare minerals, composed of peroxide of iron and silica: the former contains
about 12 per cent of lime ; the others are destitute of this earth, but contain from 10
to 20 per cent of water ; the amount of silica in these minerals ranges between 30
and 40 per cent.
1 2. Carbonate of iron ; Sparry iron ; Spadtose iron ; SphSrosiderite : Spatheisenstein,^-'
This important species has been divided into two varieties ; spathose iron proper^ and
the compact carbonate, the clay iron stone of the coal formation. Sparry iron
appears to range through nearly the same series of formations as the anhydrous
hematites : it oocurs in beds and masses often of immense extent, especially in Styria
528
IRON.
and Carin&ia. In the Ersberg, near Eiseners in Styria, it rests on gneiss, and is
wrought in an open qnarry. The Stahlbergand Momel, near Schmalkald, the Ticinhy
of Liegen, and Mosen in Westphalia, show similar extensive masses ; whilst in Anhalf
and the Harz it forms large veins in greywacke or Devonian limestone. Other very
extensive deposits of this ore are found in the Pyrenees, and the Basque provinces of
Spain, as near Bilboa ; and at Pacho near Bogota in New Grenada. Most of these
localities yield fine crystals ; and these also occur in metallic veins at Joachimsthai
in Bohemia, Freiberg in Saxony, Klausthal in the Harz, Beeralstone in Devonshire,
Alston Moor in Cumberland, and in many of the mines of Cornwall, particnlaiij
the rare hexagonal prisms (Nicol), In England the crystalline carhonate of iron
occurs in the Devonians of South Somersetshire and North Devon, and in the carbo-
niferous limestones of Northumberland.
The specific gravity of sparry carbonate of iron varies from 3^00 to 3-67. Its
primitive form is, like that of carbonate of lime, an obtuse rhomboid. Without chang-
mg this form, its crystals are susceptible of contiuning variable quantities of carbonale
of lime, till it passes wholly into tiiis mineraL When heated before the blowpipe it
turns brown without melting, and becomes attractable by the magnet after being
slightly heated in the flame of a candle. Even by a riiort exposure to the air after
its extraction from the mine, it also assumes the same brown tint, but without ac-
quiring the magnetic quality : after long expesure to the air it becomes wholly con-
verted into hydrated hsematite.
The variations in composition of this important mineral are shown in the following
analyses.
Protoxide of iron
Sesquioxide of iron
Protoxide of manganese
Magnesia - . -
Lime - - -
Carbonic acid -
Steinheim,
Hanau.
Raneff,
Pyrenees.
Eisen,
Liegen.
Ehren-
friederi*
dorf.
Soineirict^
•hire.
SomcffMi.
•hire.
63-76
0-75
0-25
traces
34-00
53-50
6-50
0-70
• «
39-20
43-59
17-87
008
0-24
38-22
3681
25-31
38-35
87-33
8-52
12-65
4-52
traces
35-80
52-56
4-82
2-41
1-25
38-68
98-75
99-90
100-00
100-47
98-82
99-72
This ore, viewed as a metallurffic object, is one of the most interesting and valnahle
that is known ; it affords natural steel with the greatest facility, and accommodates
itself best to tiie Catalan smelting forge. It was owing in a great measure to the
peculiar quality of the iron which it produces that the excellence long remarked in
the cutlery of the Tyrol, Styria, and Carinthia was due. It was called bj the older
mineralogists, steel ore.
Coal measure iron stones, — The compact carbonate of iron has no relation ex-
ternally with the sparry variety. It comprehends most of the clay ironstones, paiti-
calarly those which occur in flattened spheroidal masses of various sizes among the
coal measures. The colour of this ore is often a yellowish brown, reddish grey, or a
dirty brick red. Its fracture is close grained, it is easily scratched, and gives a yellow-
ish brown or grey powder. It adheres to the tongue, has an odour slighUy argiUaoeoDS
when breathed upon ; blackens at the blowpipe without melting, and becomes attract-
able by the magnet after calcination. The ironstones of the coal formation admit of
a natural division into two gpreat classes, viz. the argillaceous, and the blackbamd or
carbonaceous. The earthy or lithoid carbonates occur in some regions in the upper
limestone shales, and they extend upwards through the coal measures proper towards
their higher limits ; they likewise occur in extensive beds in the Jurasmc formation,
particularly in North Yorkshire ; near the upper limit of the lias, or base of the
oolites proper ; and again higher, as nodules and perhaps as beds, in the middle oolites,
or Oxford clays. They are also found extensively as courses of nodules in the
Wealden series, and as beds in the gpreen sand. When these gray carbonates contain
lime in abundance, and when clay is not largely present, they are sometimes changed
by atmospheric influences into hydrated hematites ; in Northamptonshire, for example,
and widely in France. The only great coal fields in Great Britain in which these
ores do not occur in sufficient abundance to form the basis of a large production of
iron, are those of Northumberland and Durham, and of Lancashire. The gnat im-
portance of the argillaceous and blackband ironstones of our coal-fields is dearly
shown by the fact, that they supply at least nine-tenUis of the entire iron produced
IRON.
629
(^BlackweB). Thej -wry considerably in their percentage of iron, which is generally
not more than 80 to 33 per cent., bnt occasionally ranges as high as 40 per cent
They are rarely nsed when they contain less than 25 per cent The yaryinff pro*
portions of iron, silica, and alumina which they contain is shown in the subjomed
analyses of the ore from different localities.
Water - - - -
Carbonic acid - - -
Protoxide of iron
Protoxide of manganese
lime- - . - -
Magnesia - - - •
Silica - . - -
Alumina - - - -
Peroxide of iron
Sulphuric acid - 1 j^^^
Phosphoric acid J
BimTBin.
Bretioc
I.
35-50
35-00
0-30
1-60
26-50
11-80
»>
10070
Aveyron.
II.
28-90
54-20
1-10
0-30
0-90
12-80
1-80
»>
100-00
St« Etlenne.
III.
*38-4
41*8
41
0-2
0-3
12-3
3-2
»
100-30
Scotch Vwielies.
Carbonic acid
Protoxide of iron
Protoxide of manganese
Lime ...
Magnesia - - .
Silica
A^lumina - . -
Peroxide of iron -
Carbon . - -
Sulphur ...
DS. COLQUBOUN.
IV.
V.
VI.
32-53
30-76
3517
35-22
38*80
•53-03
.
007
-
8-62
6-30
3 33
5-19
6-70
1-77
9 56
10-87
1-40
5-34
6-20
0-68
116
0-33
023
213
1-87
3-03
0*62
016
0-02
100-37
10100
98-61
Vll.
3310
47 33
013
2 00
2 20
6*63
4 30
0-33
1-70
0-22
97 94
Weigh Varieties.
Silica
Alumina (insoluble) -
Carbonate of iron
Oxide of manganese -
Carbonate of lime
Carbonate of magnesia
Alumina (soluble)
Phosphoric acid-
Salphuric acid -
Bisulphide of iron
Potash ...
Organic matter and water
Metallic iron
Dr. Noad.
Red Vdn.
VIII.
8-31
313
73-79
•92
2-95
3-80
2 52
•53
traces.
•17
•48
2-36
98-96
35-62
Red Vein
PiD.
IX.
15-40
5-00
57-99
-64
3-45
8-58
3-52
•75
traces.
•24
•45
2-34
Softp Vein.
X.
9 54
4-46
77-34
-53
•90
2-50
•57
traces.
•19
•53
2 24
98 36 I 98-80
2800
37-3
Rlaclc Pin.
XI.
12 00
4 00
71-70
1 42
2 64
4-23
115
-48
traces,
traces.
•49
1 64
99-74
84-6
VoL.IL
MM
630
IRON.
ClercloiMl Ironitonei.
Silica -
Peroxide of iron
Protoxide of iron -
Alumina
Lime - - -
Magnesia
Sulplmr
Phosphoric acid
Carbonic acid
Water - - -
Ml. ClOWDBR.
Eaiton Nmb (Main
Seun.)
XII.
11-95
6-73
39-05
13-83
2-52
2-72
trace.
1-02
16-38
5-80
100 00
XIII.
XIV.
7-65
16-55
1-20
.
43-35
87-41
9-88
9-86
0-58
3-08
5-35
trace.
009
trace.
3-87
0-67
22-36
26-82
5-07
611
100-00
100-00
HattoD Low OoH.
XV.
15-65
1-80
85-75
4-95
7-89
S-98
tract.
5-05
23-47
4-89
100-00
Blackband, from the neighbourhood of Pootypool, South Wales.
Carbonaceous matter
Carbonate of iron
Carbonate of magnesia
Carbonate of lime
Iron per cent
D>. Noia.
XVI.
15-00
61-00
10-90
18-20
XVII.
1842
64-44
13*54
8-60
100-10
100-00
29-6
31-i
The quality of the iron produced firom the argillaoeoos ironstone is eztranely good,
proTided the coals used for smelting are good. The ore is always used in t caicioed
state, by which it loses in weight abont one-third or one-fourth, the loss conaftingof
carbonic acid and water. The production of iron in South Wales, South Stiffoniihirf,
Northumberland, and Durham, rests almost entirely on the great beds of this miBenl.
In Scotland the ore almost exclusively used is the backhand or carhonaettm iniub»e,
immense deposits of which occur likewise in the coalfield of North Suiiwdsfaire;
this variety sometimes contains as much as 25 to 30 per cent of earboDSoeooi matter,
but is usually free from much earthy matter ; it often contains phosphoric scid in qnaa-
tity sufficient to communicate to the iron the quality of cold-shortness. The dJicorery
of this class of ironstone in Scotland by BIr. Mushet in 1801, and the power of oang
it alone in the Aimace by means of hot blast, constituted a new era in themsDoftctait
of iron, and gave to Scotland, till then an iron makmg district of little importsDoe, the
pre-eminence over all others, for the production of soft fluid iron, best snited to or^-
nary foundry purposes. — BlackweU,
In France the clay carbonates of the coal measures are only found of soffieient fslM
to work in three localities, — in the coalfields of the Gard, of the Avevron, and to a
blast furnace, it is not in general use.
13. FhoaphaUqfiron; Blue iron; Ftimim'^e. — The colour of this mineral Tarit*
firom indigo-blue to blackish green ; the earthy variety is white in the beds, bat
changes blue on exposure to the air ; heated in a closed tube it yields much water, in-
tumesces, and becomes spotted with grey and red ; before the blowpipe on charcoal, it
fuses to a grey, shining, metalUc granule. Transparent indigo-coloured ciystaU of
phosphate of iron, sometimes an inch m diameter and two inches long, occur with iron
and copper pyrites in the tin and copper veins at St Agnes m Cornwall It was &«<
found m the auriferous veins at Vorospatak in Liebenberg ; the earthy varieties are
-very common in Cornwall, Styria, North America, Greenland, and New Zealand.
A specmien from St Agnes, Cornwall, gave Stromeyer— phosphoric acid. SlWi P^'
oxide of iron, 41-23 ; water, 27-48 ; and another from New Jersey yielded to R«»-
melsber^— phosphoric acid, 28-40^ protoxide of iron, 33-91 ; peroxide of iron, IS'Oe, «
IS sometimes used as a pigment, but is of no use as a smelting ore.
mON. 631
14. SidphaU of iron, mUive gnen vtfa*tb£.— This is formed hj the oxygenation of snl-
phnret of iron, and is nnlmportant in a metallorgic point of Tiew.
15. ChnmaU qf iron; Octahedral chrome ere ; Chromite, — This mineral occurs in
serpentine, or in crystalline limestone, near this rock. It was first discoyend at Oassin,
in the Var department in France, and is found in Saxony, Silesia, Bohemia, and
St3rna ; also in Norway ; and in large masses in the Ural, near Katherinenberg. It has
been found also in great abundance in Unst and Fetlar, in the Zetlands ; tiie mineral
is opaque, wiih a semi-metallic lustre ; colour, iron or brownish-black, streak yellowish
to reddish brown. A specimen fWmi Norway, analysed by Von Kobell, gave protoxide
of iron, 86*66 ; sesqnioxide of chromium, 54*08 ; alumina, 9*0S; magnesia, 5*86 ; and
silica, 4*88 ; another specimen, from Chester in Pennsylvania, yielded to Seybert prot-
oxide of iron, 36*00 ; oxide of chromium, 39*61 ; alumina 13 *0 ; and silica, 10*60. It is
used in the preparation of Tarions pigments. For the treatment and use of the ore,
see Chsomb.
16. Areeniaie of iron; PharmakouiderUe i Wwrft^z, — This mineral, which is rather
rare, occurs in great beauty associated with copper ores in Cornwall ; it has an olive
green colour, and is rather brittle. Its composition, according totiie analysis of Berselius,
18, arsenic acid, 40-4 ; peroxide of iron, 28-1 ; protoxide of iron, 12*6 ; water, 18*9.
17. Mwriate of ironu
18. OxaiaU of trtm ; Oxaliie ; Humboidiine. — ^This mineral, which occurs in the form
of capillary crystals in the brown coal at Kolosoruk, near Bilin, in Bohemia, and at
Oross Almerode in Heasia, is composed, according to the analysis of Rammelsberg, of
oxalic acid, 42*40 ; protoxide of iron, 41*18 ; and water, 16*47.
1 9. Titanate of iron $ Tiianiiic iron $ lUnenile, — This variety occurs in various forma-
tions, as in the mioMcite of the Ilmen mountains ; m tali?, with dolomite, at Gastein in
Salaburg $ in the zircon-mfonite at Egersond in Southern Norway; and in gneiet, with
magnetic iron ore, at Tvedestrand, and Kragerse, near ArendaL It is extremely in-
fusible, and is considered injurious when mixed with other ores. Its chemical com-
position, according to H. Rose and Scheerer, is a combination of peroxide of iron, and
blue oxide of titanium, in various proportions, the specific gravity increasbg with
the amount of iron.
20. Tun^itate of iron ; Wolfram, — occurs with tin ore, forming fine crystals, at
Altenberg m Scaony *, at Schlackenwald in Bohemia; and in France, in quarts veins.
In Comwal], especially near Redruth, it is sometimes so abundant as to render the
tin ore wholly valueless. An analysis of a specimen from Cumberland gave Berse-
lius, tungstic acid, 78*77; protoxide of iron, 18-32 ; protoxide of manganese, 6*22 ; and
silica, 1*25.
There is abundance of evidence that iron was well known in the early ages, and
was applied to various useful purposes. The earliest method of working the ftimace
where ores were smelted seems to have been by exposing them to the wind : the furnaces,
perforated with holes, were built on eminences, and could only be worked when there
was a strong breexe ; the fire was re^pxlated by opening and shutting the apertures.
Mungo Park gives, in his *' Travels m Africa," the following interesting account of
aa iron smelting operation in Kamalia, at which he lumself assisted: ^ The ironstone
was broken into pieces the size of a hen's egg ; a bundle of dry wood was first put
into the furnace, and covered with a considerable quantity of charcoal ; over this was
laid a stratum of ironstone, and then another of charcoal, and so on until the furnace
was quite iuIL The furnace was a circular tower of clay, about 10 feet in height and 3
in diameter, surrounded in two places with withes, to prevent the clay from cracking
and fiiUing to pieces by the violence of the heat Round the lower part, on a level with
the ground, but not so low as tiie bottom of the furnace, which was somewhat concave,
were made seven openings, into each of which were placed three tubes of clay, and the
openings again plastered up in such a manner that no air could enter the famacc but
through the tubes, by the opening and shutting of which the fire was regulated. The
fire was applied through one of the tubes, and blown for some time with bellows made
of goat's skin. Hie operation went on very slowly at first, and it was some hours before
the flame appeared above the f omaee ; but alter this it burnt with great violence all the
first night, and the people who attended put in at times more charcoaL On the day
following the fire was not so fierce, and on the second night some of the tubes were
withdrawn, and the air allowed to have firee access to the furnace ; but the heat was
still very great, and a bluish flame rose some feet above the top of the furnace. On
the third £iy firom the commencement of the operation all the tubes were taken out,
the ends of many of them being vitrified with the heat, but the metal was not removed
until some days afterwards, when the whole was perfectly cool ; part of the furnace
was then taken down, and the iron appeared in the form of a large irregular mass, with
pieces of charcoal adhering to it It was sonorous, and when any portion was broken
off, the fracture exhibited a granulated appearance like broken steeL"
mm2
532 IRON.
That the iron ores of Monmouthshire and Gloucestershire were extensively worked
by the Romans daring the period of their reign in Britain is certain, from the immense
beds of iron cinders that have been discovered in the Forest ol Dean ; it is probable
that Bath was the principal Sbat of their foundries ; relics of their operations, in the
form of cinders, and coins, have likewise been discovered in Yorkshire and in other
counties. During the reign of William the Conqueror, Gloucester was the city where
the trade of forging iron was chiefly carried on, the Forest of Dean supplying the
ores. It is uncertain when the art of casting was first disooTered ; cani^n are sap-
posed to have been first used in England by Edward the Third, who used them in his
invasion of Scotland in 1327, at Cressy, and at the siege of Calais in 1346. These
cannons were not however cast, but were constructed on the same principles as coopers
construct their barrels ; a number of iron bars fitting as close as possible to each other
were arranged round a cylinder of wood, and were then bound together by strong iron
hoops ; the wood beiag driven out, there remained an iron pipe whiqh formed the barreL
This mode was superseded by ccuting the cannon of bronze.
Daring the 1 4th and 15th centuries, iron and steel were imported into this conntry
from Germany, Prussia, and other places, and also iron from Spain ; bat as several
improvements in the manufcu^ture had taken place in the course of this period in
England, laws were made towards the conclasion of the 15th century, prohibiting the
importation of any of the articles manufactured in this country in iron and steeL During
the reign of Elizabeth, the consumption of charcoal by the iron furnaces was so great
that it was deemed necessary to enact laws to prohibit the erection of new famacea»
and to prevent the felling of timber for fuel ; persons interested in the manufacture
of iron were consequently compelled to turn their attention to the finding of some
substitute for charcoal, and in the rei^s of James the First and Charles the First many
attempts were made to smelt iron with pit-coal, but without success ; the cooseqaence
was the entire abandonment of iron making in many parts of the country, and a great
decrease in the manufacture in others ; so complete indeed was the failure of all the
experiments made to substitute pit coal for charcoal, that all attempts were abandoned
till the early part of the next century, when pit-coal was first used (1713) by Blr.
Abraham Darby in his furnace at Colebrook Dale ; and in the 44th volume of the Philo-
sophical Transactions, published in 1747, it is stated, that '* Mr. Ford, from iron and
coal, both got in the same Dale (Colebrook), makes iron brittle or tough as he pleases,
there being cannon thas cast so soft, as to bear turning like soft iron.** Notwithstand-
ing, however, the establishment of the fact that iron ore could be smelted, and iron
manufactured with pit-coal, and although great efibrts were made, by increasing the
column of blast, by the substitution of steam power for that of horses and homan
labour, there appears to have been a steady and progressive diminution in the quantity
of iron produced in this country ; and recourse was had to foreign markets, particu-
larly to those of Sweden and Russia, for the necessary and increasing demand. Thus^
the imports of iron between the years 1711 and 1776, were as follows : —
Tons.
1711 to 1718 15,642
1729 „ 1735 25,501
1750 „ 1755 34,072
1761 „ 1766 48,980
In 1740 there were only 59 blast furnaces in work in England and Wales, the total
make of which amounted to not more than 17,350 tons, being an average of 294 tons
per annum for each furnace, a quantity very little exceeding that sometimes made in
a single week in some of the furnaces in Wales at the present day.
The earliest contrivance for throwing a powerful and constant blast into the furnace
was a forcing pump, worked by a water wheel or by a steam engine ; and it appears
that the first cylinders, at least of any magnitude, were erected at the celebrated
Carron Iron Works in the year 1760 by Mr. John Smeaton. These cylinderF were
four feet six inches in diameter, exactly fitted with a piston, moved up and down by
means of a water wheel ; in the bottom of the cylinder was a large valve, like that
of a bellows, which rose as the piston was lifted up, and thus admittea the air into the
cavity of the cylinder below. Immediately above the bottom was a tube which went
to the ftimace, and as it proceeded from the cylinder, was furnished with a valve
opening outwards. Thus when the piston was drawn up, the valve in the bottom
rose snd admitted the air that way into the cylinder, while the lateral valve shut, and
prevented any air from getting into it through the pipe. When the piston was
thrust down, the valve in the £)ttom closed, while the air, being compressed in the
cavity of the cylinder, was violently forced out through the htteral tube into the
mON. 533
furnace. There were four of these large cylinders applied to blow the furnace, and
so contrived, that the strokes of the pistons, being made alternately, produced an
idmost uninterrupted blast A large column of air, of triple or quadruple density, was
thus obtained, and effects equivfdent to these great improvements followed. The
same furnace that formerly yielded ten and twelve tons weekly now sometimes produced
forty tons in the same period, and on the average in one year 1,500 tons of metal
(Scrivenor) ; and such was the impulse given to the trade by this unexpected success
of a powerful blast with pit-coal, that in 1 788 the manufacture of pig iron in England,
Wales, and Scotland amounted to 68,300 tons, being an increase of 50,950 tons on
the quantity manufiustured previous to the introduction of pit-coal.
A new era in the history of the iron manufkcture may be considered to have been
established in 1788-90, by the introduction of the double power engine of James
Watt, the regular and increased effects of which powerful machine were soon felt
in most of the iron districts : the proprietors of furnaces greatly increased their make,
and f^^sh cspital was embarked in the trade : in the short period of eight years, the
manufacture of pig iron was nearly double, being in the year 1 796, (according to the
returns sent to the chairman of the committee of the House of Commons, on the sub-
ject of the coal trade, when Mr. Pitt had it in contemplation to add to the revenue by
a tax upon coal at the pit mouth,) 125,079 tons,fh>m 121 furnaces — 104 English and
Welsh, and 17 Scotch; the English and Welsh fbmaces producing an average of 1 ,048
tons each per annum, and the Scotch furnaces 946 tons. In 1806, the number of
furnaces in blast in Great Britain was 173, and the make 258,206 tons of pig iron,
being an increase in ten years of 133,127 tons per annum ; of these 162 were coke
furnaces, the average produce of each of which had risen to 1,546 tons. In this year
great excitement existed in the iron trade, in consequence of the proposal of Lord
Henry Petty to levy, as a war tax, a duty of 40s. per ton on pig iron ; he introduced
a bill into the House of Commons having this object, and succeeded in carrying it,
notwithstanding a powerful opposition, by a minority of ten members; the measure
was however abandoned.
In France, in 1801, the quantity of cast iron produced amounted to 140,000 tons
firom 550 blast furnaces, of which only one (that of Creusot) was worked with coke.
In 1809, a description of the English process of making iron was published by order
of council, by M. de Bonnard (an engineer of mines); another engineer of mines
(M. de Gallois), after having passed several months in England, established at St.
Btienne the second blast furnace in France, wherein the minerals were treated in the
same manner as the English, and in which coke was employed ; but the difficulties
he had to encounter proved a bar to his success, and he is said to have died prema-
turely from Uie grief and trouble which the enterprise occasioned him (Scrivenor.)
The employment of pit-coal in the manufacture of iron received a very slow develop-
ment in F^nce, for m 1818 the quantity of cast iron made with coke was very small,
and no wrought iron was prepared with pit-coal ; in 1824 not more than 3,000 tons of
cast iron were made with coke, but in 1828 it had risen to 17,000 tons. Though this
did not amount to a tenth of the whole produce, nevertheless the quantity of bars made
with pit-ooal amounted in this year to 48,000 tons, being nearly one-third of the
total manufacture of wrought iron.
Cast iron, using that term in the sense in which it is now understood, must have been
wholly unknown to the ancient metallurgists, for even in the smelting of their poorer
ores, where they urged their furnaces with the greatest heat they could command,
using probably lime as a flnx, the reduced metal was allowed to cool in the bed of the
furnace, and was never run into pigs as in the modem practice ; their best iron was
produced in one operation, and after cooling and separating the scorisa, it was forge<l
at once into tough hard bars under the tilt hammer. The time and fuel consumed
in these ancient methods was enormous, and the iron that remained in the scoriae,
amounted to fully one half of the original metallic contents of the ore.^
The modern processes of iron smelting differ materially according as the fuel
employed is charcoal or pit-coal. As an illustration of the method adopted when the
former is used, the following details of the manu&cture of the celebrated " Oeregrund
iron " may be taken, premising that the operations vary in a few particulars in other
countries where different kin& of ore are dealt with. The oeregrund iron is made
from the magnetic ironstone of IHmnemora in Sweden. The ore, m moderately large
pieces such as it comes fVom the mine, is first roasted. For this purpose an oblong
coffer of masonry, 18 feet long, 15 feet wide, and about 6 feet in de^th, open at top,
and furnished with a door at one of its smaller extremities, is entirely filled with
logs of wood : over this the ore is piled to the height of firom 5 to 7 feet, and is
covered with a coating of small charcoal, almost a foot and a half in thickness. Fire
is then communicated to the bottom of the pile, by means of the door just mentioned,
MM 3
534
moN.
and in a short time the combustion spreads throogh the whole mass; the ima& quntity
of pyrites that the ore contains is decomposed by the Yolatilisation of the solphnr : tiie
moisture is also driven off, and the ore, from being very hard and refractory, be-
comes pretty easily polverisable. In the space of twenty-fonr horns the roaating is
completed : and ihe ore when sufficiently cool is transferred to a stamping mill,
where it is pounded dry, and afterwards smed through a network of iron, which wHl
not admit any piece lar^ than a haael-nnt to pass. It is now ready to be smelted.
The smelting furnace is a strong quadrangular pile of mason^, the internal fonn
of which, though simple in form, is not very easily described, it may be consideied
in general as representing two irregular truncated cones, joined bsise to bttse ; of
these the lower is scarcely more than one-third of the upper, and is pierced by two
openings, throu(^h the upper end of which the blast of wind trom the blowing
mAchine is admitted into the furnace ; and from the lower the melted matter,
both scorie and metal, is discharged fh>m time to time at the pleasure of the
workmen.
The furnace is first filled with charcoal alone, and well heated, after which alter-
nate charges are added of ore, either alone, or mixed with limestone (if it requires
any flux) and charcoal ; the blast is let on, and the metal in the ore being lughly
carbonised in its passage through the upper part of the furnace, is readily melted
as soon as it arrives in Uie focus of the blast, whence it subsides in a fluid state to the
bottom of the furnace covered with a melted slag. Part of the clay that closes the
lower aperture of the furnace is occasionally removed, to allow the scoriss Co flow oot,
and at Uie end of every ninth hour the iron itself is discharged into a bed of saoid,
where it forms from ten to twelve small pigs. As soon as the iron has florwed out,
tiie aperture is closed again, and thus the furnace is kept in incessant activity during
the first six months of die year, the other six months are employed in repairing the
ftimaoes, making charcoal, and collecting the rec^uisite provision of wood and ore.
The next process for converting; the pig mto bar iron is refinin^f : for this purpose a
furnace is made use of, resembling a smith's hearth, with a slopmg cavity, sunk from
ten to twelve inches below the level of the blast-pipe. This cavity b filled with
charcoal and scorisd, and on the side opposite to the blast-pipe is hud a pig of cast
iron well covered with hot fheL The blast is then let in, and the pig of iron being
placed in Uie very focus of the heat, soon begins to melt, and as it liquifies;, runs
down into the cavity below : here, being out of the direct influence of the blast, it
becomes solid, and is then taken out, and replaced in its former position. The cavity
being then filled with charcoal, it is thus fused a second time, and after that, a third
time, the whole of these three processes being usually effected in between three aod
four hours. As soon as the iron has become solid it is taken out, and very sligfaUy
hammered to free it f^m the adhering scoris : it is then returned to the furnace, and
placed in a comer, out of the way of the blast, and well covered with charcoal, where it
remains, till, by farther gradual cooling, it becomes sufficiently compact to bear the
tilt hammer. Here it is well beaten till the scorin are forced out, and it is then divided
into several pieces, which, by a repetition of heating and hammering are drawn into
bars, and in this state is ready for sale. The proportion of pig iron obtained from a
given quantity of ore is subject to considerable variation, from the difference in
the metallic contents of different parcels of ore and other circumstances ; but the
amount of bar iron that a given weight of pig metal is expected to yield is regulated
very stricUy, the workmen being expected to furnish four parts of the former for five
parts of the latter, so that the loss does not exceed 20 per cent
In some parts of America, particularly in tiie states of Vermont and New Jersey,
the Catalan forge is extensively employed for smelting the rich magnetic ores which
there abound* The form of this fire
'** (which is nearly uniform every whereX
and the manipulation with it in Ame-
rica, is thus described by Overman:
— The whole is a level hearth of stcme
work, from 6 to 8 feet square, at the
comer of which is the fireplace, frtnn
24 to 30 inches square, and fWnn 15
to 18, often 20, inches deep. Inside it
is lined with cast iron plates, the
bottom plate being fhmi 2 to 3 inches
thick. Figurt 993 represents a cross
section through the fireplace and tu-
yere, commonly called tne iron; d re-
presents the fire-place* which, as remarked above, is of various dimensions. The
tuyere b u firom 7 to 8 inches above the bottom, and more or less inclined ac-
IRON. 5S5
oordiug to olroDiDftaDCM. Tbe blail fi prodaced b; Tooden b«UaT* of tlia eommoa
fom, or mote generally bj (qBue wooden cjlinden, urged by ntw vbreli. Tha
on eUefl; emptoyod u the
erTttslliKd TBMgotac ore. This
ore TciT iwdilj' lUli to a
GouM nod, and vben roaalcd
varies from the die of a pea
to the flncM grain. SomtttmM
the ore ii eB^oyed vWiMit
Toeeting. b ue voifcing of
•veb fire* mneh depends on tbe
akM sad eiperience of tbe
vorkmuL Tbe r««ult la »ah-
ject to coDiidenble TUiatirai,
that ii, whether eoonomj of
coal or that of ore ii oar ob-
ject. Thnt a modiflcaxioD U
reqaued in tbe coniCnieiJoa
cither of tbe whole apparMoi
or in parti of iL The manipa-
lation varies in many reepecti.
One workman by inelining bia
tajrere to tbe bottom, aarea
coal at tbe expense of obtain-
ing a poor yield. ADOther b;
carrying bia tne iron more bo-
riiontally at the eonmence-
ment, obtains a larger amoont '
of iron, tboogh at tbe laerifice of coaL Good workmen pay great alteation to
the tuyere, and alter iti dip according to the Uste of tbe openklion. The general
manipalalkm ia aa Ibllows : — The besrtb is lined with a goiid coating of ebarcoal
dost i and tbe fire plate, or the plate opposite (be blast, u lined with coarse ore,
in cue any is M oor ditposaL If no coane ore is employed, tbe hearth is filled with
coal, and the small ore piled agunst a dam of coal dost opposite the tayere. The
blast ia at lint aned gently, uid directed upon the ore, while tbe coal aboTe the
tuyere is kept eodC Fonr bimdred ponnds of ore are the common charge, two-thirds
of which are thna amelled, and tbe remaining third, generally tbe finest ore, is held in
reterte, totae thrownon Uie charcoal when the fire becomes too brisk. The charcial
it [riled (o tbe bright of two, sometimes eien three and four feet, according to the
amoont of ote to be smelted. When tbe blast has been applied for an boor and s half,
or two honn, moat of tbe iron is melted, and forms a paaly maai at the bottom of the
beanb. The blast may no* be urged more strongly, and if any pasty or spongy
IBB** yet remains, it may be brooght within the range of tbe blast and melted down.
In a ahort time the iron ia reviled, and the scorite are permitted to flow through the
tapping liole c, so that bat a imall quantity of cinder remuns at the boltom. By
means of iron bars, the lamp of pasty iron ia brooghi before the tuyere. If the iron
1 pwty to be lifted, (he Inyere is made to dip into the hearth ; in this way the
' ■ efbre, or to a point ' '
r fifteen inches ii
broQgbl to tbe hammer or sqneeser, and shingled into a bloom, which ia either cut in
piecea to be stretched by a hammer, or sent to the rolling mill to be formed into
marketable bar iron. A mixture of fibrons iroo, cait iron, and steel, is the reiall of
tbe above proceas i the quality of the iron depends entirely on the quality of the ore,
for (here are no opportunities for the exercise of an» Ekill to create improrements in
tbe proeeaa ; poor orea oannot be smelted at all. In Vermont, where the rich mag-
netic ofca are employed, a ton of blooma costs about 40dollars ; 4 tona of ore, and 300
boabels of ebareoal are required to pradoce 1 ton of blooms. The Founuattx d
piiet of the Frencb, or SUtei-ojiii of the Germans, holds a place intermediate be-
tween the Catalan htarA and tbe liigh blast Aimace now in general use. Tbe iron
prodnced in thii kind ol fttmace is genersllv of a very superior kind, but it ia very
little in use at tbe present time, on acconnt of tbe great expense of its manipnlstion.
The Staei-ofoL, or salamander fumace, as it is sometimee called, is a small cupola., its
interior hsTiag the form of a double crucible. It is usually f^om ID to 16 feel high,
and S4 inches wide at bottom and top ; and measurea at its widest part about 5 feet.
There are generally two tnyeret, both on the aame side ; the breast is open, but du-
ring the tndting operation it is shut by bricks. The furnace is heated previous to
ok^ng in the breast ; after whieh obanoal and ore are thrown in ) the blast is then
536 IRON.
tnraed on i M kod u the ore pasBei the tQfere, iron i( deponttd Kt the boUom of tbr
betrtb ; when the cinder Hwe to the tuyere, s portion ii inffeTed to escape throngfa b
bole in the dam : the (uteres are generaltj kept low Dpon the inrfsce of the melted
iron, which thai becomei whitened : ai ibe iron riiea the tuyerei ire nited. In
■boot 34 boon one ton of iron is depotited at the Imttom of the faimce, the bUM it
fjj^ turned off. u>d the iron, which
it in B solid muE, in the fonn c/
■ wlamander, or SiSci volf, at the
Germsni call it, is iifled loose from
the bottom bj crowbars, takm
by a pair of strong tonga, which
are bitened on cbiini, tiupendcd
on • (wing crvie, and then re-
mored to an anril, where it ii flat-
tened bj a tilt hammer into four-
inch thick elabs, eat into blooms,
and finally stretched into bar Itdii
by imaller hammen. Meanwhile
the fnmace is charged anew with
ore and coal, and the aame pto-
ceaa ii renewed. Thia proees.
at well aa that of (he CvMlan
hearth, ia impracticable with am
coDtaiaing mach foreign matter,
or leae Ihaa 40 per cent of metal
The general farm of the nu-
dera charcoal bla*t fbmaec, ti
nsed in the United Scatca, where
thia ftiel ia fhr more common tbiD
pit-coal (indeed, it it doabtfol
whether any coke fnnuoa are at
, the present time in operation ia
(hat eonnlry), ii ibown in vertical
Hclion in fig. 994, and in aeetkn
throDgh the tuyere archei in jEf.
... 99S. The orer detign«d to be
■melted in thla fumac« are hy-
drated oiidea of iron, uch ai
brown hiematite, brown iron atone,
pipe ore, and bog orea. Thebeighl
is 3S feet ; hearth ftvm base to
the boahea, 5 feet, 6 inches ; width
at the bottom, 24 inches ; and at
top, 36 inches. The tuyere* an
£0 inches abore the bue. The
buahes are 9 feet 6 inches in dia-
meter, and measure from the top
of the crucible 4 feet, which giTCt
about fiU° slope. The blast is
conducted through abeel-iron or
cast-iron pipes laid below the bot-
tom stone into the tuyeres: Tbe
top is fiimished with a chimney,
by which the btaie from the tunnel
head ii drawn off. Around the
top is a fence of iron or wood.
f^. 996 shows the method ofptv-
paring and arranging the hearth-
stones, d ii the botlom stone,
madeof a fine close-grained nnd-
Btone, fraai 13 to IS inches thick,
at least 4 feet wide, and 6 feel
. long ; it reaches nndemeatfa at least
' half of the dam-slone b. This
bottom stone is well bedded in
flre-clsf, mixed with Ihree-fburtht tand. After the bottom slone is placed, the npper
part of wliich moM be tbree-fourtbt of no inch lower at the dam-ilooe than m the
IRON. «3r
back, the two (ide stoaea c, are laid embedded in fire-clay. Tbfte ilone* moM
be at least 6 tevt tmd a half long, reaching from 18 inchea bebind Ibe cnunble to tbe
middle of the dam-slone. Their gc|g
fonm if meet commonl; sqaare, ,
thftt il, a prism of four equal {
tidei ; tbe tTanarene section of I
the grain maic be in all caaei |
placed tawai^]s the flre ; tbe side
iloDC* are Ktmetimes iqnire, but
ofteaer bcTclled according to the
■lope of the hearth. Upon these
Btooes the tuyere ttones d are
bedded; tbe latter luffeT mach
from heat, and therefore onght (□
be of the beat qnaliiy. Thej
•faonld be from SO to 34 inchA
tqiure, or even larger: the tuyere
holes /, • kind of taper arch, are
cat out before the atonei are
bedded. Theae stones do not ~
reach further (ban to the front or timpstoue a, and are therefore scarcely Ibur feet
long; tbe lop stone ;, ii generally sufficiently high to raise at once the crucible 10 it*
destined height. After both sides are fioiabed the back slooe I is put in, and then
tbe timpstoue, g ; the space betveeu the hearthstanes and the rough wall of the
furnace stack is filled aud walled up with cammon brick or stones.
In starting a charcoal fnraace, it is first ihoroughly dried by burning a fire for
lereral weeks in the interior, which has a temporary lining of bricks. The lower
part of the furnace or the hearth ia then filled gradoallj with charcoal, and when the
fbel is well ignited, and the furnace half filled, ore may be charged in ; it ia some-
times adriaable to increase the draught by forming grates by laying across the timp a
■horl iron bar, as high upas the dam-stone, by resting upon this bar six or aeien other
ban or ringers, and by putbing their points against the back stone of the hearth.
There is not much iron made during the first 34 hours; most of the ore is transformed
into slag, and the iron which come* down gets cold on the bottom stone, where it is
retaioedi the blast should not be urged too fkit at first, hut increased gradually, in
order to avoid the serious evil arising from a cold hearlfa ; if all goes on well the hearth
will be ftte from cold iron or clinkers in a week, the yield of iron will increase, nod
tbe burden may be increased likewise. The average charge of charcoal, which should
be dry, coarse, ai^ hard, is about 15 bushels. According to Overman's eiperieoee,
the most favonrafile height for a charcoal furnace is 35 or 36 feet; if below this
standard they consume too much fuel, if above they are troublesome to Bork ; if it be
desired to enlarge the capacity of a fiimace, be thinks it better to increase the
diameter of tbe boshea, or to curve the vertical aeetion. There is much difference of
opinion amongst managers of furnaces on the subject of the proper size for the throat
of tbe furnace; the tendency of narrow throats would seem to be to consume more coal
than wide ones, inasmuch as in Pennsylvania and throughout the whole west, where
narrow tops are preferred, tbe coDsumption of charcoal per ton of iron is from ISO to
igO bushels, while in the state of New York, and further east, where tbe furnace throats
^ ar» wider, the consumption is from 120 to 130 bushels. Another subject which
^demands the strictest attention is tbe regulation of the blast. A weak sot^ charcoal
will not bear a much greater pressure than from half a pound to five-eightbs of a
pound lo the square inch; strong coarse charcoal will bear from three quarters of a
pound to a pouiid; and again, it may be laid down as a rule that tbe larger tbe throat
m proportion to the boshes, the stronger ought to be the blast, and that a narrow top
and wide boshes, while they permit a weaker blast, involve tbe loss of much fuel. In
every case a careful roasting of the ores at charcoal ftamaces will prove advantageous ;
this Ls the surest means of saving coal and blast, and of avmding many anuoyancca in
the working of the furnace.
With regard to bot blast, as applied to charcoal fumaces, Overman remarka, that
nnder some circumstance* it might be advantageous, but in others it is decidedly
injurious i that it is, at least, a questionable improvement, and it may be doubted
whether the manufiicture of bar iron has derived any benefit from it ; qualila-
lioely it has not. Hot blast is quite a help lo imperfect workmen : it melts refractor;
ores, and delivers good foundry metal with Acility.
EiigliMh proceu of iron makoig. — Mr. Hunt, in his very valuable " Mineral Sla-
588 IRON.
Northumberland ------- 45,312
Durham 265,184
Yorkshire, North Riding 189,320
Do. West Riding 85,936
Derbyshire- - - .... 131,677
Lancashire - - 2^40
Cumberland - - 26,264
Shropshire -- 101,016
North Staffordshire 135,308
South Staffordshire and Worcestershire - » 597,809
Gloucestershire .-.---- 23,530
Northamptonshire --•... 9,750
Wilts and Somerset ...... 2,040
North Wales 28,150
South Wales 886,478
Scotland 925,500
3,456,064
The number of furnaces in blast to furnish this astonishing make are, in KnglanJ,
332, distribnted over 162 iron works; in Wales, 153, distributed over 57 works; and
in Scotland, 133, orer 32. To supply- these furnaces there were raised 8,040,959
tons of ore, the ettimated value of which, at a mean of 1 U. per ton, is 4,423,527iL ;
that of the pig iron, at a mean money value of 4l a ton, being 13,824,256)1 Of the
ironstone 1,650,000 tons were argillaceons carbonate from the coal meanires of Staf-
fordshire and Worcestershire; nearly 1,500,000 tons from the coal measures of NorUi
and South Wales $ and 2,212,250 tons argillaceous carbonate from Scotland. The an-
nual production c^ pig iron over the whole worid was estimated by Mr. Bladiwell, in
December, 1855, as follows : —
Tons.
Great Britain 3,000,000
France 750,000
United States of America ..... 750,000
Prussia -.------ 300,000
Austria ........ 250,000
Belgium ---.---- 200,000
Russia ........ 200^000
Sweden 150/)00
Various German States ..... 100,000
Other eonntries ...... :roo,000
6,000,000
From which it appears that the quantity of iron made annually in this island aloMDc^
is nearly, if not quite, as large as the totid quantities produced m all other ooimtrie«»
The nature of the ore which forms the staple supply of the English fhmaoes (argil-
laceous carbonate), and the universal adoption of coke and coal as fuel, have fed hj
necessity to a metiiod of manufacture of iron quite peculiar to this country, and wholly
inapplicable to those establishments that are carried on by means of charooal. We
shall proceed to describe the various steps <^ this manufacture in detail : — and first.
Of the blastfurnace, — The blast furnaces at present in use are of various sizes, b^g
from 35 to 60 feet in height, and at the boekes, or widest part, fSrom 12 to 1 7 feet. The
internal form commonly adopted consists essentially of two frustmms of cones meeting
each other at their bases, at the point where the widest part or the top of the boshes
is sitnated. From this point the frimace gradually contracts both upwards to its
mouth, and downwards to the level of the tuyeres below. Hie hearth, properly speak-
gg. ing, is that part of the Ihrnaee only
which receives the fluid metal and
*/y _^__ cinder, as they fiiU below the lev«l of
the tuyeres. It forms a diort pro-
longation from that point of the kywcr
inverted cone. From the boahes
upward the width gradually decreases
to the tunnel head, which varies fittm
7 to 9 fret in diameter, according to
the sise of the fnmaee. The hearth
is generally a cube, from 2^ to 3 feet
sqnare. The air is introduced by one, two, or three small apertores, called ttq^trm.
IRON.
539
998
When two tuyeres are nted, tbe orifiees of their blowpipes are about three inches in
diameter, and the pressure of the blast is from 3^ to 3 lbs. on the square inch. To
preTent the tnyeres fh>m being melted by the intense heat to which they are ex-
posed, a stream of cold water
IS cansed constantly to flow
ronnd their nossles by an
arrangement which will be
immediately understood by
an inspection of fig, 997,
whieh represents a section
of a tayere nozzle thus pro-
tected, the cold water en-
tering the casing by the tube
a, and the hot water run-
ning off by the tnbe b. The
upper part of the furnace
above tiie boshes is called
the cone or 6o^. It is formed
by an interior lining of fire-
brick, about 14 inches in
thickness, between which and
the exterior masonry is a
casing of fine refractory sand
compactly rammed in, air
holes being left for the escape
of aqueous vapour. In the
base of the fhmace four
arches are left, the back and
sides are called Unftre houses,
the front is called the citukr
JoH; the bottom of the frur-
nace is formed either of large
blocks of coarse sandstone or of large fire-bricks. The materials are charged into
the fnmace through the tunnel head, which is provided with one or more apertures
for the purpose. The general form of a blast furnace is shown in fig. 998, and the
following measurements represent the interior structure of two that worked well: —
Height from the hearth to the throat or mouth -
Height of the cmcit^ or hearth ...
n of the boshes- . . . . -
„ of the cone - - ...
n of the chimney or mouth ...
Width of the bottom of the hearth* . - -
„ at its upper end • • - • -
„ oftheboshesf • . - • -
„ at one-third of the belly ...
„ at two-thirds of ditto • . - -
„ at mondk •.•>..
Inclination of the boshes $• . . . .
No. 1.
- 45 -
- 6^ -
- 8 -
-30^-
- 8 -
- 3
- 121
- 12
5S-
69* -
Mas.
49
6
7
36
12)
2
21
13]
111
9J
5^
Fig, 999 represents the hearth and boshes in a vertical side section, a is the tymp
stone, and b the tymp plate, for confining the liquid metal in the hearth. The latter
is wedged firmly into the side walls of the hearth ; c is the dam-stone, which occupies
the whole breadth of the bottom of the hearth, excepting about six inches, which space,
when the fhrnace is at woi^ is filled before every cast with a strong binding sand.
This stone is ftused outside by a cast-iron plate d, called the dam plate, of considerable
thickness and peculiar shape. The top of the dam-stone, or rather the notch of the
dam-plate, lies from 4 to 8 inches under the level of the tuyere hole. The space
under the tymp plate, for 5 or 6 inches down, is rammed ftill for every cast with a
strong loamy earth or even fine clay, a process called tymp stopping.
• The width of th« h«rth dtflim greatly to the fanuoei to dUtorant locslitfes. In Scotland itrjoiet
froateteSfeet; to the Webh ftinMu»e from ft to 8 feet. When coke U uwd «• ftiel Mr. Truran think*
6 feet a fofficient width for all porposea ; hat with coal, with ftill-aUed Airnaoei, 16 to 19 toet acroa the
boehee, he thinks a 7 feet heartn to be more adTantaoeous. .a#^^
t The dtometer of the boehes to aome of the Welah furaacea if at much at firom IS toI9 feet.
t The angle with which the bodiei rise to different ftimaces Tariea fnw" M© 'oj?!* iJE^'uTrSS?
thlnkt that when the fhU imelttog power of the tomace if desired, the angle should not be less than 7(P,
whidi is about that of the Scotch ftiraaces.
540
moN.
99§
The blowing machines employed in Staffordshire are generally cast-iron cylinderi)
in which a metallic piston is exactly fitted as for a steam engine, and made in the same
way. Towards the top and bottom of the blowing cylinders orifices are left covered
with vaWes, which open Inside when the ra-
cnum is made with Uie cylinders, and after-
wards shut by their own weight Adjutages
conduct into the iron globe or chest the air
expelled by the piston, both in its ascent and
descent, because these blowing machines haye
always a double stroke.
The pressure of the air is made to rary
through a very considerable range, according
to the nature of the fuel, and the season of the
year : for as in summer the atmosphere is nM>re
rarefied it must be expelled with a compen-
sating force. The limits are from Ij^ to 3^
pounds on the inch, the average in StajSotd-
shire being 3 lbs. The orifices, or nose pipes
through which the air issues, also Tary ^^th
the nature of the coke and the ore.
In a blast apparatus employed at the Cyfartfaa
works, moved by a 90 horse steam power the piston rod of the blowing cylinder
is connected by a parallelogram mechanism with the opposite end of the working
beam of the steam engine. The cylinder is 9 feet 4 mches diameter, and 8 feet
4 inches high. The piston has a stroke 8 feet long, and it rises 13 times in the
minute. By calculating the sum of the space percursed by the piston in a minate, and
supposing that the volume of the air expelled is equal to only 96 per cent, of that
sum, we find that 12,588 cubic feet of air are propelled every minute. Hence a
horse power applied to blowing machines of this nature gives on an average 137
cubic feet of air per minute.
At the establishment of Cyfartha for blowing seven smelting flimaces, and tl^e
seven corresponding fineries, three steam engines are employed, one of 90 horse power,
another of 80, and a third of 40, which constitute on the whole a force of 210 horses,
or 26 horses and ^th per furnace, supposing the fineries to consnme one*eighth of the
blast. In the whole of the works of Messrs. Crawshay, the proprietors of Cyfartha, the
power of about 340 horses is expended in blowing 12 smelting furnaces and their
subordinate fineries; which gives from 25 to 26 horses for each, allowing as before |th
for the fineries. Each of the furnaces consumes about 3,567 cubic feet of air per
minute.
The form of the blast furnace from the boshes to the throat ia exhibited in fiff, 998
as a tpjncated cone, and such was formerly invariably the construction ; of late yean
however considerable variations have been introduced. In Scotland the body of the
furnace frequently is carried up cylindrical, or nearly so, for a considerable height,
terminating with the usual truncated cone to the mouth; in other places a curved line
is substituted for a straight one. The form adopted in some furnaces recently
erected at Ebbw Vale and Blaina is shown in^^. 1000.
The diameter of the throat or filling place is a subject of very great importance to the
operations of the furnace. Most iron masters are, we believe, agreed as to the impolicy
of the narrow tops formerly adopted-, the waste of fuel in such furnaces, where the
width of the throat scarcely averaged one- fourth of the diameter of the furnace, was
very great, the average yield of coal to the ton of crude iron exceeding 6 tons ; by
enlarging the throat to one-third, the consumption of coal was reduced to 4 tons, and
by continuing the enlargement to one-half it was reduced to 2 tons. Mr. Truran
states that on reducing the diameter of the throat of a furnace at Dowlais from 9 feet
to 6, the make of pig iron weekly fell off from 97 tons, to an irregular make of from 50
to 70 tons ; and that while with the 9 feet throat the consumption of coal was 45 cwts.
to the ton of iron, it rose with the 6 feet throat to 70, 80, and 90 cwts., the quality of
the iron being exceedingly bad. On enlarging the throat to 9^ feet, tiie make, for a
period of 6 months, averaged over 160 tons, with a good yield of coal and other
materials. Mr. Truran appears to question the utility of reducing the diameter of the
furnace at the top, which was only adopted in the first place from an erroneoos
impression that the furnace could be filled best through a contracted mouth ; but it
may be questioned whether this widening of the throat may not be carried too te, so
as to disperse the heated gases too rapidly, and whether a diameter much greater than
one-half of tlie largest dimensions of the furnace above the boshes can wiUi utility be
adopted. On this subject Mr. Kenyon BlackweU says, " If that part of the blast
furnace aommcacmg U Uie poml where it attuu iti grtUtst niiOi wire contbiied
of the nme vide dimeuumi opwkTds to itt month, two objectioeable multa
ol^ectioeable multa
fint the upper
part of the fuT-
1 Dace would be
r cooled by the
_ too rapid dii-
peraion of the
of heated giiei,
bunceof the re-
f the coDtracted
\j, the mBteriali
ay apread from
CT of the upper
therefore, to be
e the material*
ing holes to dii-
equallr in their
part of the tee-
iiraace. and will
erberalioD only
■oScient to ei-
carbonic acid
Bterials, wilhont
be carbon of the
o remua intact
lower region* of
it i* vapoiised
and prodocea
hich the reduc-
b amuUmt. —
her in kilna, or
be object being
lubttancei Tola-
The operation
effectually, and
nalleat coat, la
ir ahape of the
tn ia different
r all be reduced
imon lime liiln.
lighted at the
and the iron-
alone ia placed over and around,
until the floor ii corered with red
hot ore ; a freah layer of ironatone,
with abont H per cent, of coal, ia
then laid on, to the depth of 8 or 9
inches ; and when thia ia red hot,
a aecond layer i< added, and to on
gradnally lilt the kihi ia filled; by
the lime Ihia is Aine, the lowermoat
layer is cold and fit to draw, ao that
the working of the kiln ia a con*
tinnouB operation. When the ore
ia calcined in the open nir, a heap
mingled with small coal (if neces-
sary), is piled op over a stratum of
larger pieces of coal, the heap heing
9 or 6 feet higb, by IS or !0 brood,
Tbe Sre ia applied at the windward
end, and afler it hai bornt a cer-
542 IRON
tain way, tlie beap it prolonged at the otber extremity, ag fhr at the nature of the
groond, or the conyenience oiwork requires. From the impoisibility of regnbitiiig the
draught, and from exposure to the "Weather, the calcination of ore cannot be so well
performed in the open air as in kilns ; and as to the relative cost of the two methods.
Mr. Tmran calculates that the quantity* of coal per ton of ore is, in the kiln, <me hva-
dred- weight of small ; and in the open air, two hundred-weights of small, and a half
handred-weigbt of large ; and that while the cost of filling the kiln is barely a
penny per ton, that of stacking the heaps on the open air plan, and watching them
during the period they are under fire, amounts to fourpence per ton. Against
this must, however, be placed the cost of erecting the kiln, whicn according to the
same authority amounts, for a kiln of a capacity equal to 70 tons of argillac^os ore^
which will calcine 146 tons weekly, to 160Z. The ironstone loses by calcining from
25 to 30 per cent of its weight ; it has undergone a remarkable change by the opera-
tion; in the raw state, it is a grey or light brown stony looking substance, not ai-
tracted by the magnet ; after calcination it has a dry feel, adheres stroBgly to the
tongue, is cracked m idl directions, is of a light reddish colour throughout, uod acts
powerfully on the magnet It should be carried to the fhmace as soon as possible^ or
if kept should be carefully protected from the rain.
Fiux, — The only flux that is used in the blast fbmace is limutonef either in the state of
carbonate as it comes from the quarry, or calcined in kilns, by which it is depriTed of
water and carbonic acid. The lowest bed of the coal formation usually rests on
limestone, and in the coal formation itself are found not only the ore and its most
appropriate foel, but the pebbly grits which affoid the blocks <i refractory stone neees-
sary for building those parts of an iron furnace that are required to endure the utmost
extremity of heat, as well as those seams of refractory clay, of which the fire-bricks
are composed, with which the middle and upper parts of the furnace are Uned. ** Thus
many situations in thu fltvoured island may be pointed out, in which all the above
mentioned materials occur almost on the same spot ; and when to this is joined the
convenience of water carriage, as happens in many places, that man must indeed
be of an obtuse understanding and a churlish temper in whom this wise arrange-
ment and prodigal beneficence of nature fiuls to produce corresponding feelings."
The composition of the limestone to be used in smelting operations is of consider-
able importance ; where calcareous ores are used, the presence of silicic acid in the
limestone is advantageous ; if clay ores are the main material from which iron is ma-
nufactured, a magnesian limestone is preferable, but an aluminous limestone shoahl
be used where siUceons ore predominates. Chemical analysis alone can determine to
which class a particular limestone belongs, as there is often nothing in the external
appearance by which a pure limestone may be distinguished from one containing 40
or 60 per cent of foreign matter.
Carbonised pit-coal or coke was, till within the last twenty-five years, the sole com-
bustible used in the blast furnace. Coal is coked either in the open air or in kilns.
In the former, as practised in Stafforddiire, the coal is distributed in cirenlar
heaps about 5 feet m diameter by 4 feet high, and Uie middle is occupied by a low
brick chimney piled with loose bricks, to open or to leave interstices between them,
especially near the ground. The larger lamps of coal are arranged round this
chimney, and the smidler ones towards the circumference of the mass. When every-
thing is adijnsted a kindling of coals is introduced into the bottom of the brick
chimnev, and, to render the combustion slow, Uie whole is covered with a coat of coal
dross, the chimney being loosely covered with a slab of any kind. Openings are
occasionally made in the crust, and afterwards dbiut up, to quicken and retard the
ignition at pleasure during its continuance of twenty-four hours. Whenever the
carbonisation has reached the proper point far forming good coke the oorering
of coal dross is removed, and water is thrown on the heap to extinguish the coin-
bastion, a circumstance deemed useful to the quality cf the coke. In this operation
in Staffordshire cAd loses the half of its weight, or two tons of coal produce one of
coke.
In order to prepare larger quantities of coke at once, long ridges are often sohsti-
tuied for circular heaps, the length of which varies with circumstances and the eon-
sumption of coke ; they sometimes extend to the length of SOO feet On ereeting one
of these ridges a string is stretched along the coking station, in the direction of which
large pieces of coal are placed slanting against each other, leaving a triangular space
between them, so that a longitudinal channel (ignition passage) is formed through
which the string passes. In arranging the pieces it is necessary to pay attention to
the natural stratification of the coals, which should be at right angles to the langitodinal
direction of the ridge. Parallel with the first series of coals is placed a Bewsod, and
IRON. 548
then a third, and lo on ; Imt the pieces constantly diminish in sise nntil the station
measures 6 feet on both sides. Upon this snhstmctare the heap is then made,
withont particniar care in the arrangements, the largest pieces below and the smallest
aboTe, until it has reached a height of about 3 feet To ihcilitate the ignition, stakes
are rammed in at distances of 2 feet flrom each other, projecting above throughout
the whole length of the ridge, which, when subsequently removed, leave vacant
spaces for the introduction of burning coal. The ridge, berag thns kindled at more
than 100 distinct spots, soon breaks out into active combustion. As soon as the burner
obeerves the thick smoke and flame cease at any one part, and a coating of ash
making its appearance, he endeavours immediately to stop the progress of the fire by
covering it with powdered coal dust, repeating the operation until the whole ridge is
covered, when it is left two or three ^ys to cool ; the covering on the side exposed
to the wiod should be thicker and increased in stormy weather. When the nre is
nearly extinguished, which occurs in two or three dinrs, the ooke is drawn. This
mode of coking is simple, but not very economical. The fire proceeding fh>m the
upper part of the ridge in a downward direction, towards the lower and interior parts,
converts the coal in £e upper strata into coke before that in the interior has acquired
the temperature necessary for charring, and is still in want of a supply of air, which
can only be furnished from without, and must not be excluded by a covering. Ihiring
the time, therefore, that the inner parts of the heap are being converted into coke, the
outer portions are being uselessly, Uiough unavoidably, consumed. For further details
concerning coking see the articles Coil and Coks.
The " blowing in " of a coal blast furnace is an operation which requires much
care and experience. A fire of wood is first lighted on the hearth ; upon this is
placed a quantity of coke, and when the whole is well ignited, the furnace is
filled to the throat with regular charges of calcined ore, limestone, and coke, and
the blast, which should at first be moderate, is turned on. At the works around
Merthyr Tydvil, the first charges generally consist of 5 cwts. of calcined argil-
laceous ore and 1 } cwt. limestone, to 4 cwts. of rich coke ; this burden is kept
on for about 10 days, it is then increased to 6 cwta of calcined ore and 2^ cwts. of
limestone (TVaran). The cinders usually make their q>pearanee in about 12 hours
after blowing, the metal follows in about 10 hours after, collecting in the hearth to the
amount of 3 or 3} tons in 60 hours after blowing. If all goes on well about 22 tons
of metal will be produced in the first week, 38 tons in the second, 55 in the third, and
nearly 80 in tiie fourth; after 10 or 12 weeks Ac produce will average 110 tons.
By forcing the fbmace in its inftacy a much ffreater produce of iron may be obtained,
though to the injury of its subsequent workmg. Mr. Truran relates the following
case in point. A fbmace was blown in at the Abersychan works with such volumes
of blast and rich burden of materials that a cast of several tons was obtained within
14 hours after applying blast The first week's blowing produced 200 tons, at which
ratie it continued for two or three weeks, when it rapidly diminished, fiilling so low as
19 tons for one week's make. From this deplorable state it was made to produce 26
tons, and, after considerable delay, 100 tons ; but with a large increase in tfie yield of
materials over that at the other ftimaces. When a ftimace is first blown in it should
be made to produce grey iron ; but the tendency of forcing is to produce a white iron
with a dark scouring cinder.
The quantity of air thrown into a blast ftimace in fhll work is enormous, exceeding
in weight the totals of all the soiled materials used in smelting. A ftimace working
on foundry iron of a capacity of 275 yards receives 6390 cubic feet of air per
minute, which amounts weekly to 1695 tons ; when working on white iron a larger
volume of blast is employed, averaging 7370 cubic feet per minute, or 2318 tons per
week.
The disorders to which blast furnaces are liable have a tendency to produce white
cast iron. The colour of the slag or scorio is the sorest test of these derangements,
as it indicates the quality of the products. If the furnace is yielding an iron proper
fbr casting into moulds, the slag has an uniform vitrification and is slightly translucid.
When the dose of ore is incrmed the slag becomes opaque, dull, and of a greenish
yellow tint, with blue enamelled xones. £ist1y, when the ftimace is producing white
metal, the slags are more or less black and glossy. The scoria firom a coke are much
more loaded with lime than those ftom a charcoal blast ftimace. This excess of lime
appears adapted to absorb and carry off the sulphur which would otherwise injure the
quality of the iron. From numerous analyses we have made of blast furnace cinders
we select the following as illustrating their general composition under different condi-
tions of the ftimace.
544
IRON.
Ancdysea of Blast Furnace Cinders. (Dr. Noad.)
Slltca .
Alumina - - -
Lime . . -
Magnesia •
Protoxide of manganese
Protoxide of iron
Potash . . -
Sulphuret of calcium -
Loss ...
I.
IL
IH.
IV.
V.
VL
VIL
40^20
17-00
30-34
7-16
traces
1-90
1-96
1*70
•43
38-49
14-19
84-35
6-14
1-54
910
1-48
1-16
•69
41-19
22-00
99-48
1-88
traces
8-60
not determined
1*09
•83
40 50
12-48
96-55
3-90
11-20
3-20
1-15
9-90
•59
49-40
91-06
1756
4-96
1-04
3'eo
-87
] 1-49
40-66
37-33
10-30
9-75
9-00
13-19
1-90
•46
42-95
ao-»
10-I9
9-90
1-53
l9-»
I 1-39
100-00
100-00
100-00
100-00
100-00 100-00
ivyw
I. Mean of four analjrses of grey iron cinders from a furnace at Blalna, South Wales. II. Mean of
four analyses of grey iron cinders from an iron woric in Staffbrdshire. III. Mnm of four
analyses of grey Iron (cold blast) cinders flrom Pontjrpool, South Wales. IV. Mean of faar
analyxes of green cinder trom a furnace at Ebbw Vale, Monmouthshire, smelting spathoee ore.
V. Mean of four analyses of blast furnace cinders from Sweden. VI. Mean of four analrses of
white iron cinder /rom a furnace at Cwm Celyn Iron Works, Monmouthshire. VI L Meanot
four analyses of white iron cinder from the same works, the furnace " scouring.**
The following table exhibits the "yields** of materials per ton on the iron made
in Tarious works. During the month ending July 25th, 1857, there were consamed
in four furnaces at Ebbw Yale 1354 tons 14 cwt of coke ; 1792 tons of coal ; 2440
tons 19 cwt. of calcined mine; 1818 tons 10 cwt. of red ore; 1347 tons 6 cwt of
calcined cinders ; and 1226 tons 7 cwt of burnt lime. The quantity of pig iron
made was 2305 tons 7 cwt : —
Yields of Materials per Ton of Iron.
Calcined mine
Hsematite -
Cinders
Coal
Limestone -
cwt.
48
0
0
50
17
II.
cwt.
28
10
10
42
14
II.
cwt.
0
10
95
36
16
IV.
V.
cwt. cwt
46
0
0
coke
34
16
33
0
0
40
5
VL
cwt.
27
10
0
coke
34
IS
VU.
c«t.
21
K
1
1
34
13
VIIL
cwt.
4*
IX.
cwL
H
0
18i
I. Dow lais foundry iron. II. Dowlais forge iron. III. Dowlais Inferior forge iron. IV. Hlnrain
foundry iron. v. Dundyvan, Scotland, foundry iron. VL Pontypool cold blast foundry iron.
VIL Ebbw Vale forge iron. VIII. Cwm Celyn forge iron. IX. Coalbrook Vale foundry iron.
The '* cinders" mentioned in the foregoing table are not those trom the blast
fomace, but are derived firom the cast iron during the processes of ^'refiniDg,**
" puddling," &c., by which tho cast iron is converted into wrought iron. These
cinders are very rich in iron, which exists in them principally in the form of silicate
of the protoxide. They oflen occur beautifully crystallised, particularly after they
have been calcined, an operation which is always performed on them m well con-
ducted works, and which has for its object the removal of the sulphur and the per-
oxidation of a portion of the iron. These cinders, though very rich in iron, are
always contaminated to a considerable extent with both sulphur and phosphorus^ as
might be expected, seeing that they are the results of operations which have for their
objects the removal of the foreign matters contained in the pig iron. The tendency
of the former is to make the metal what is called *' hot short," so that it cannot be
worked while hot under the hammer ; the tendency of the latter element is to make
the iron " cold short,** so that it breaks when an attempt is made to bend it when cold.
The separation of sulphur is very perfectly effected by the calcination of the cinder,
and it is interesting to trace the progress of its gradual elimination. In some parts of
the heap (which often contains several thousand tons of cinder) large masses of
prismatic ciystals of pure sulphur may be found, but usually nearly the entire surihce
of the heap is covered with a thin layer of sulphate of iron, sometimes crystallised,
but g:cneraily in various stages of decomposition ; lower down in the heap, where the
heat is greater, the sulphate of iron disappears, and in its place red oxide of iron,
without a trace of sulphur, is found. In calcining a heap of cinders care is required
not to allow the heat to rise too high, or immense masses will become melted together,
involving the necessity of blasting, which entails much expense. After the heap has
been burning for some months, streams of water are directed over the surface, bj
IRON.
54$
which much solable sulphate of iron is removed. Unfoitonately, the process of
calciiation does not remove any of the phosphoric acid, which necessitates a jadicioos
employment of these cinders m the blast fnmace. We have repeatedly submitted
'* forge cinders*' to analysis, and give in the following table the average results of our
experiments.
Anatyiet of Forge Cinderg. (Dr. Noad.)
Silica -
Protoxide of iron
Pemxide of Iron
Stilphurec of Iron
Oxide of manganese -
Alumina
Lime ...
ll«ffnesla
Phospliorie add
I.
II.
III.
IV.
V.
VI.
6-000
63 750
11-420
6*766
1-680
2*400
1*232
traces
7-268
6-67
72-60
6 30
4-56
1-77
2-22
-12
traces
6*36
82-000
62»200
6KIG0
1-953
not determined
0-600
traces
traces
-252
15-800
61-720
10-980
6-306
-960
1*300
•420
traces
4 140
12.300
67*360
2-8.M>
6*600
not determined
6*600
traces
traces
6 320
12*800
10*500
70-000
-620
1-140
-427
traces
traces
4-&0()
99*516
09-60
101*106 00-216
100-030
99-987
I. Tap cinder from refined metal. II. Tap cinder from puddling furnace. III. Cinder from
re-heating ftimace. IV. Mixed cinder fk-om the heap after a fewdavs' burning. V. Cinder
squeexed out of the puddled bar during the process of shingling. VL Specimen fk>omalarge
hrap of thoroughlj calcined cinder.
Hot blast — One of the greatest improvements ever made by simple means in any
manufacture, is the employment of hot air instead of the ordinary cold air of the at-
mosphere, in supplying the blast of furnaces for smelting and founding iron. The
discovery of the supenor power of a hot over a cold blast in fusing refractory lumps
of cast iron, was accidentally observed by Mr. James Beaumont Neilson, engineer to
the Glasgow Gas Works, about the year 1827, at a smith's forge in that city, and it
was made the subject of a patent in the month of September in the following year.
No particular construction of apparatus was described bv the inventor by which the
air was to be heated, and conveyed to the furnace ; but it was merely stated that the
air may be heated in a chamber or closed vessel, having a fire under it, or in a vessel
connected in any convenient manner with the forge or furnace. From this vessel the
air is to be forced by means of a bellows into the furnace. The quantity of surface
which a heating furnace is required to have for a forge, is about 1,260 cubic inches ;
for a cupola famaoe, about 10,000 cubic inches. The vessel may be enclosed in
brickwork, or fixed in any other manner that may be found desirable, the application
of heated air in any way to furnaces or forges, for the purposes of working iron, being
the subject claimed as constituting the invention.
Wherever a forced stream of air is employed for combustion, the resulting tempe-
rature must evidently be impaired by the coldness of the air injected upon the fueL
The heat developed in combustion is distributed into three portions ; one is commu-
nicated to the remaining fuel ; another is communicated to the azote of the atmosphere
and to the volatile products of combustion ; and a third to the iron and fluxes, or other
surrounding matter, to be afterwards dissipated by wider diffusion. This inevitable
distribution takes place in such a way, that there is a nearly equal temperature
over the whole extent of a fire-place, in which an equal degree of combustion
exists.
We thus perceive that if the air and the coal be very cold, the portions of heat ab-
sorbed by them might be very considerable, and sufBcientto prevent the resnlting tem-
perature from rising to a proper pitch ; but if they were very hot they would absorb
less caloric, and would leave more to elevate the common temperature. Let us sup-
pose two furnaces charged with burning fuel, into one of which cold air is blown, and
mto the other hot air, in the same quantity. In the same time, nearly equal quantities
of fuel will be consumed with a nearly equal production of heat ; but notwithstanding
this, there will not be the same degree of heat in the two furnaces, for the one
which receives the hot air will be hotter by all the excess of heat in its air above
th^t of the other, since the former air adds to the heat while the latter abstracts from
it. Nor are we to imagine that by injecting a little more cold air into the one fur-
nace, we can raise its temperature to that of the other. With more air indeed we
should bum more coals in the same time, and we should produce a greater quantity
of heat, but this heat being diffused proportionally among more considerable masses
of matter, would not produce a greater temperature ; we should have a larger space
heated, but not a greater intensity of heat in the same space.
Thus, according to the physical principles of the production and distribution of
heat, fires fed with hot air should, with the same fuel, rise to a higher pitch of tern-
Vol. II. NN
548 IBON.
jxrUnN Am Ini fed with «omau» ocdd air. Thii conwqMiMe ii indcpaadaat of
the oiuies, being m true for b, mull itoTe Thich bom only ui oonoe of ehaicoal
In a minute, u for • foniRce whieli bonu a hnndnd-veight i but ike ezc«aa of
temperature produoad b^ hot air Monot be the (una in smell fire* u w gtctt, be-
cause the waite of best u niually less tba more fuel ii horned.
This principle maj be roDdered still more eTident bj a Dumerical illiutiatioD. Let
01 take, for example, a biait fnmaee, into which GOO onbio feet of air •!« blows
nicute ; suppose it to contain do ore but merelj coal or coke, and rhat it ha*
baminR lon|( enough to have arrived at the eqoilibriom of lemperalore, and
ici ui see irhat excess of temperature it would have if blown with air of 300° C.
($73" P.). instead of being blown with air at 0° C-
600 cubic feet of air. nnder the mean temperature and pretsure, weigh a littla
more than 45 pounds ftToirdupois; they contain 104 pounds of oxygen, which
would bum very nearly t pounds of oarbon, and disengage 16,000 times as maeh
beat as would raise by one degree per cent, the temperature of two pounds of water.
These 16,000 portions of heat, produced every minute, will replace 16,000 otbo'
portions of heat, dissipated by the sides of the furnace, and employed in hfaiing
the gases which escape from its month. This must take place in order to eatsb-
lish (he assumed equilibrium of caloric
K,
If the 49 pounds of air be heated beforehand np Co 300° C, they win eea-
lain about the eighth part of the heat of the 16.000 disengaged by the combos-
SuB, and there will be therefore in the nme space one-eighth of hnt more, which
IRON. 847
will be rMdy to ap«raM npco U17 bodiei vithlii Iti rtnge, ind to beat thorn one-
cifditli more. Thus tha blut of 300° C. gifei & tempersEiire vhioh ii nine-eighthi
of (he bbat U lero C, or ■! «Ten the oriinmrr •tmo«|ih«rio lempenttiire ; and ai
wo may reckon st fcom 2,200" lo 2,?0Q= F. (from 1,200° to 1,500° C), the tempe-
ntQTO of bbat ftamacea worked in the commoa irky, we perceive that the hot-air
blast prodacea aa lacreaaa of temperature equal to fW>m 270° to 360° F.
Nov in order to appreciaie the immcnae effecta which thia exceaa of tempera-
ture may produce in metallargic opentioBS, ve miut couider that often only a
Eew dcgreri more temperature are required to modify the itate of a fiuible body,
or to determine the play of aiEnitles dormant at lower degree* of heat. Water u
aolid at 1° under 320 T. ; it is tiqaid at 1° above. Every Aigible body hai a deter-
minaw meltiag point, a very fewdegreva above which it ia quite Add, though it may
be partly below it. The same observation appliei to ordinary cbemlcBl affinities.
Charcoal, for example, which redaces the greater part of metaJtio oxide*, begina loi
do 10 only at a determinate pitch of temperature, under «hieb it i» inoperative, bat a
few degree* abOTe, tt U in general Urely and complete. It ii tm\j in tlu
■rticle to enter into iny more details, to ibow the ioQnence of a few degree* of hell
more or leu in a hirnace npon chemical opecationa, or merely upon phytical cbanga
Figt. 1002, 1003, ezbibil the apparatn* oT the hoi UaM a* moonted at the Colon
Park vorks, belonging to William JeMOp, Eaq., in ereiy reqoiute detaiL The dni-
inga fh>m which the wood-cuU are failbfullj copied were kindly Aunithed for thic
work by Mr. Joseph GIjd, F.R.S.. the diftingaiabed engineer of the BnUeriy Iron
Works,
The RDelting furaaee* hare now generally three tnj^ret, and (bree aeti of ur
heating furnaces. The figarei ihow two sets built tcvelher ; the third set beingde-
tiched on account of peculiar local circnnutances. Tbe air enters the horiaanul
pipe A, in tbe groaod ■B]a,o, Jig. 1002, oa oat side of tbe arcbed or syphon pipM,il»wn
in upright section in J^. 1003, and passes throngh these pipes (o the horiiontnl pipe.B,
OD the other side ; whence it proceeds to the blast furnace. These sypbon pipes are
flattened Uterslly, their KcliaD being a paraUelogTam, to give more heating sorftce,
and siso more depth of pipe (In tbe vertical plane), so as to make jl atronger, and kas
liable to bend by its own weight when softeaed by tbe red heat Thia sy steal of
arched pipe apparatus is set in a kind of oven, from which the fine i* taken ont st the
lop of it; but it thence again descend^ before it reaches the chimney, entering it
nearly at the level of the fire g^te, (as with coal gas retorts). By this eontrinnct,
the pipes are kept in a ba:b of ignited air, and not expoaed to tbe corroding inSaenoc
of a current of fiame. Tbe places and directions of these oven floes are plainly marked
in the drawing.
Fiji. 1004 ia a plan of the blast furnace, drawn to a smaller sctde than that of the
preceding flgnrea.
The three sell of hot-blaat apparatus all conimunicate with one line of cooduetii^
IRON. 549
pipeSi A, whidi leads to the furnace. Thus in case of repairs being reqaired in
one set, the other two may be kept in full actiTitj, capable of supplying abundance of
hot air to the blast, though of a somewhat lower temperature. See Smbltino for
ooostnictions of different blast furnaces } also Pudduno.
During a visit which Dr. Ure made to Mr. Jessop, at Bntterly, he found this emi*
nent and yery ingenious iron-master had made several improvements upon his hot-
blast arrangements, whereby he prevented the alteration of form to which the arched
pipes were subject at a high temperature, as also that he was about to employ five
tuyeres instead of three. For a drawing and explanation of his furnace-feeding
apparatus, see SMELTiNa
The experiments through which Mr. Nielsen's important discovery was introduced
into the iron manufacture, were made at the Clyde Iron Worl^ where the fhel ge-
nerally made use of was coke, derived from splint coal; during its conversion into
coke, this coal sustained a loss of 55 per cent During the first six months of the
year 1^29, when all the cast iron in the Cljde Iron Works was made by means of
the cold blast, a single ton of cast iron required for fuel to reduce it 8 tons l^ cwt of
coal, converted into coke. During the first six months of the following year, while
the air was heated to near 300^ F., 1 ton of cast iron required 5 tons 3^ cwt of
coal converted into coke. The saving amounts to 2 tons 18 cwt per ton of iron,
from which must be deducted the coal uMd in heating the air, which was nearly 8 cwt
This great success induced the Scotch iron-masters to try a higher temperature, and
to substitute raw coal for coke ; and during the first six months of the year 1 833, the blast
bein^ heated to 600^, I ton of cast iron was made with 2 tons 5} cwt of coal. Add
to this 8 cwt of coal for heating, and we have 2 tons 13^ cwt. of coal to make one ton
of iron. An extraordinary impetus was given by this discovery to the iron manu-
ftcture in Scotland, where, from the peculiar nature of the coal, and from the cir-
cumstance that, witi^ a heated blast Mushet's blackband ironstone could be exclusively
used, its importance was more highly felt than in England and Wales. According to
Mr. Fmch's statement (Scrivener's " History of the Iron Trade ")♦ *!>«*« ▼«!« in 1830
only eight works in operation in Scotland, which made in that year 37,500 tons of
pig iron ; in 1838 there were eleven works, consisting of 41 fixmaces, which made
147,500 tons, being an increase in eight years of 110,000 tons per annum ; in 1839
^ere were 50 furnaces in blast, making 195,000 tons ; in 1851, 750,000 tons of
pig iron vere made ; and in 1856, with 127 furnaces in blast, the make rose to
880,500 tons. The influence of hot blast has likewise been felt in the anthracite
district of South Wales, where that coal is now successfully used, and where several
new furnaces have in consequence been erected. In short, notwidistanding the oppo-
ntion with which the introduction of hot blast was met by engineers, as being de-
structive of the quality of the iron, so great have been the advantages derived from
it, that at Uie present time more than ninete^n-twentieths of the entire produce of the
kingdom is made in furnaces blown with heated air.
Mr. Truran, in his recent work on the iron manufacture of Great Britain, gives it
as his opinion that the effects of hot blast have been ^catly exaggerated, and that it
is to improvements in the preparation of fuel and ore m the furnaces, in blowing en-
gines, and in the smelting process, far more than to the heating of the blast, that we
must refer the great reduction in the yields of coal in recent times ; he thinks that
the comparatively large produce which has been obtained fVom the Scotch furnaces, is
to be referred to the general use of carbonaceous ore, which melts at a low tempera-
ture ; and which, from its comparative freedom from earthy matters, requires but a
minimum dose of limestone for fluxing. Against this opinion of an English writer on
iron smelting we may place that recorded by an American metallurgist Mr. Overman,
-who has written a large and in many respects a valuable treatise on the manufietcture
of iron, as conducted in America. " The economical advantages arising fh)m the
application of ho( blast, casting aside those cases in which cold blast will not work at
all, are immense. The amount of fuel saved in anthracite and coke furnaces varies
from SO to 60 per cent In addition to this, hot blast enables us to obtain nearly
twice the quantity of iron within a given time that we should realise by cold blast
These advanta^s are fkr more striking with respect to anthracite coal than in relation
to coke or to bituminous cod. By using hard charcoal, ire can save 20 per cent of
fuel, and augment the product 50 per cent From soft charcoal we shall derive but
little benefit, at least where it is necessary to take the quality of the iron into con-
sideration."
The following tables, embodying the general results of an extended scries of experi-
ments on the relative strength and other mechanical properties of cast iron, obtained by
the hot and cold blasts, are extracted from a report presented to the British Association
(1837) by Messrs. Eaton, Hodgkinson, and William Fairbairn.
Of the three columns of numbers, the first represents the strength or other quality
NN 3
550
IRON.
in the coid blast iron, like second ihat in the hot, the third is the ratio of these qunlilies ;
the figures included in parentheses indicate the number of experiments from which
the resalts have been deduced.
Camon Ikon, Ko. 9.
Teniile strength in Ibi. per square Inch -
CompreMire strength in Ibi. per inch, from
castings torn asunder • . • - *
Ditto, (torn prisms of rarloos forms - - -
Ditto, ttom cylinders . . - , -
Transverse strength from all experiments
Power to resist impact . . . - •
TraniTerse strength of bars one inch square
in lbs.
Ultimate deflection of da ta Inches - . .
Modulus of eUstidtj in lbs. per square inch -
Specific gravity -------
C«UBlasu
DiTOM laoM, Ko. 3.
Tensile strength ..---.
Compressive strength . . . . -
Transverse do. from experiments generally
Power to resist impact . - - - -
Transverse strength of bars one inch square -
Ultimate deflection do.
Modulus of elasticity .--•--
Specific gravity -------
CoBD Talov Ihon, No. 1
Tensile strength ..----
Compressive strength - . - - -
Specific gimvity ...-.-.
16,688 (9)
106,875 (8)
100,681 (4)
185.408 (13)
- (11)
- (9)
476 (8)
1-818 (3)
17,370.500 (2)
7,006
Carrom Iron, Ko. 8.
Tensile strength - . .
Compressive strength
Specific gravity - . - .
BuvrsRT Iron, Ko. 1.
Tensile strength . . - . .
Compressive strength . - . .
Transverse strength -----
Power to reaist impact . - - -
Transverse strength of bars one inch square
Ultimate deflection do. - - - -
Modulus of elastioity - - - • -
Specific gravity ------
BetBlMC
99|907,700 (a)
7,2W (4)
18.859 <2)
81,770 (4)
6.955 (4)
14,200 (S)
116.542 (4)
7.135 (1)
17.466
93»366
468 <3)
1-55 (3)
15,881.200 (2)
7,079
18,506 (8)
108,540 (2)
100.738 (2)
121,685 (18)
. - (18)
• - (9)
Cold
bf U
(8)
1*887 (8)
16,065,000 (2)
7.046
21.907 (1)
145,435 (4)
- (5)
587
1D9 (2)
98,478.650
7,229
(9)
(9)
(9)
(9)
16.676 <3)
82.739 (4)
6,968 (4)
17.755 (2)
188.440 (8)
7,066 (I)
18,484
86,397
436 (8)
1-64 (3)
18,780.500 (2)
6,958
1000 : 809
1000 : 10»1 a
1000 : 1001 V SWi
1000 : 970) 6*"
1000 : 991
1000 : lOQft
1000; 973
1000 : 1018
1000 : 991
1000 : 997
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
1000
KOO
1000
1000
1000
1000
1000
1000
MOO
1417
1199
IMO
991
991
884
1018
1809
19S0
1196
925
931
949
1058
898
These results oontain nearly the "whole of the information afforded by the investi-
gation. From the numbers in the tables, it will be seen that in Bnffery iron Na 1
cold blast somewhat surpasses hot blast in all the following partioulars . — 1*
direct tensile strength ; 2, compressive strength ; 3, traosverse strength ; 4, power
to resist impact ; 5, modulus of elasticity or stiffness ; 6, specific gravity ; while the
only numerical advantage possessed by the hot blast metal is that it bends a little
more than the cold before it breaks. In No. 2 the advantages of the rival kinds are
more nearly balanced, still rather in favour of the cold blast. Na 3 hot blast CarnNi
iron resists both tension and compression better than cold blast of the same denomi-
nation ; and Na 3 hot blast from the Devon works in Scotland is remarkably strong
while No. 3 cold blast is comparatively weak, notwithstanding its high specific gravity.
On the whole it would appear iVom the experiments, that while the irons of Na 1 have
been somewhat deteriorated in quality by the hot blast, those of No. 3 have been
benefited by its mollifying powers ; while those of No. 2 have been but very slightly af-
fected ; and from the evidence brought forward, it is rendered highly probeble thai
the introduction of a heated blast, whilst it has, perhaps, to a certain extent, injured
the softer irons, has improved those of a harder nature ; and considering the small
deterioration that the irons of the quality Na 2 have sustained, and the apparent
benefit of those of Na 3, together with the saving effected by the heated Uast, there
seems good reason for the process becoming so general as it has done*
The following general summary of results, as derived from the experiments of
Messrs. Hodgkinson and Fairbaim on the transverse strength of hot and oM blast
iron exhibits at one view the ultimatum of the whole investigation.
moN.
551
Tbese irons are from Mr. Hodgkinson's experi-
ments:^
Carron iron. No. S -
Devon iron. No. 8 - - - - ■
Biiffrej iron, Na 1. -
These irons are from Mr. Fairbaim*s ezperi*
ments: —
Coed Talon iron. No. 2 - - - -
Coed Talon ditto, Na 3 -
Elsicar aod Milton, ditto - - . •
Carron ditto. No. S -
Miiirkirk, Nob l - . . - -
Ratio of Strentth :
IhatofColdBlMt
being repreient-
adbjrIOOO.
1000 t 990-9
1000 : 1416-9
1000 : 9307
1000 : 1007
1000 : 927
1000 : 818
1000 t 1181
1000 : 927
1000 : 1024-8
Ratio or fowen to
tuit«ln Impact;
Cold Blast belDg
1000.
1000 : 10051
1000 : 2785*6
1000 t 9621
1000 : 1234
1000 : 925
1000 : 875
1000 : 1201
1000 : 823
1000 : 1226-3
Dr. Thompson's cbemieal examination of several samples of hot and cold blast iron
is appended to this report According to the experiments of tlus distinguished
<diemist, iron smelted by hoi blast contains a greater proportion of iron, and a smaller
proportion of silicon, carbon, and alominnm, than when smelted by cold air. Hie
mean specille graTity of 8 specimens of Scotch cold blast iron No. 1 was 6*7034 ; the
mean of 6 specimens of hot blast from the Carron and Clyde iron works was 7 0623,
so that the density of cold blast iron is less than that of hot The mean of 6 analyses
of cold blast iron No. I gave 3} atoms of iron, 1 atom of carbon, silicon, and alami-
nnm; tiie proportion of these three oonstitnents being very nearly 4 atoms of carbon,
1 atom of siKoon, and I stom of almnhram, consequently Scotch cold blast iron consists
of 20 atoms of iron (with a little manganese), 4 atoms of carbon, I atom of silicon,
and 1 atom of alominmn. The meaoot of 5 analyses of hot blast iron No. I, gave 6^
atoms of iron and manganese to 1 atom of carbon, silicon and aluminam, from which
it woald appear that cast iron smelted with a heat blast is purer than when the blast
is cold. This however, is not the case* as the nnmeroos analyses of both varieties
that have been made daring the last few years concur in provrag. Hot blast grey
iron smelted with mineral ooal contains a much higher peroealage of silicon than the
same variety of cast iron smelted frt>m the same ores by cold blut ; in other respects,
provided the process of redaction is eomplele, t. s. when little or no iron passes off with
the slag, there is very little chemical difference between the two varietieB, as will be
seen in the following table, which contains the results of a series of analyses of hot
and cold blast iron, which we have lately had occasion to make, nnder onrcumstances
peculiarly &vomrable for instituting the comparison, the furnaces working with the
same ores, and making the same class of iron, via. good No. 3 grey pig.
Analifses of Cast Iron No. 3, smelted by Hot Blast (Da. Noad.)
Silicon -
Graphite
Sulphur
Photptionis
I.
2-600
8-520
0*046
0^318
II.
III.
3140
3'tOO
O'OSO
a42a
8-380
8-210
0079
0-308
IV.
2-440
0009
0'3»4
V.
8-200
8 340
0-073
0-482
VI.
8-190
3'320
0046
0*460
VII.
8 120
3-340
0-ort
0-820
Vlll.
2-960
8-294
0*064
0-374
Me«n.
2-T.OO
3-V90
0-0C7
0-379
HoUllie iron per cent*
»S*1S
Analyses of Cast Iron No. 3, smelted by Cold Blast (Dr. Noa]>.)
Sllleon .
Gnqihlle
Sulphur -
Photpboriu
I.
1*050
8-370
0-024
0*210
II.
1-400
3- 184
0-087
0*314
III.
1*029
3-270
0.045
0-887
IV.
0*940
8*140
traces
0-361
V.
1872
8-883
0-029
0*372
VI.
1-486
8-274
0-037
0-872
VII.
1-466
8-242
0-028
0'8«2
VIII.
1-400
8197
0-024
0-354
Metallic iron per cent.
9S-0
Mean.
1-268
8-251
0*028
0-339
The true reason of the frequent inferiority of hot blast iron has been correctly given
by Mr. BlaokwelL Furnaces blown with heated air exert greater reductive power
NN 4
652 IRON.
than those m which a cold blast is used. This has led, since the introdoetion of hot
blast, to the extensive nse in iron smelting of refractory ores not formerly smelted, a
large part of which have been ores of a class calculated to produce inferior iron, aod
it is to the use of ores of this nature, far more than from any deterioration in qoalitj,
arising from a heated blast, that this inferiority of hot bhist iron is to be ascribed.
Utuisation of the waste gases given off from the furnace head, -r- The agent in the
blast furnace by which the oxide of iron is reduced, is carbonic oxide, the presence of
which therefore in great excess is indispensable to the operation of the furnace. The
flames rising from tiie tunnel head, which make a bfast furnace at night such an im-
posing object, are occasioned principally by the combustion of this gas, on coming into
contact with the oxygen of the atmosphere ; the attention of practical men was first
called to the enormous waste of heat which this useless flame entailed by Messn.
Bunsen and Playfair, and the application of the gas to a useful purpose may be ranked
next to that of the heated blast, as the most important of the recent improyements in
the iron manufacture. The gases eyoWed from iron furnaces where coal is used as
the fuel, contain the following constituents, yiz. nitrogen, ammonia, carbonic acid, ear'
bonic oxide, light carhuretted hydrogen, ol^fiantgas, carhuretted hjfdrogen of unknown com'
position, hydrogen, sidphuretled hydrogen, and aqueous vapour. The nature of the
combustible gas stands in a relation so intimate to the changes suffered by the
materials put into the furnace, that its different- composition in Uie yarions regions of
the furnace indicates the changes suffered by the materials introduced as they descend
in their way to the entrance of the blast. Now as the examination of this column of
air in its yarious heights in the furnace must be the key to the questions upon which
the theory and practice of the manufacture of iron depend, it was of the fint import-
ance to subject It to a rigid examination ; this accordingly has been done by the above
named eminent chemists, and subsequently by Ebelmen. We shall return to a consider-
ation of the results they obtained presently, confining our attention at present to the
composition of the gases at the mouth of die furnace, and to the methods which have
been adopted to utilise thenL
In order to arrive at a knowledge of the composition of these gases, H. Bunsen
first studied minutely the phenomena which would ensue were the furnace filled with
fuel only : by a careful distillation of a known weight of coal, and analysing of the
products, he obtained results embodied in the suljomed table : — -
Carbon --.-.... 68*925
Tar 12-230
Water 7669
Light carhuretted hydrogen - . . • . 7^21
Carbonic oxide - • - - • - -1*135
Carbonic acid ....... 1*073
Condensed hydrocarbon and olefiant gas - - 0*753
Sulphuretted hydrogen -.---. 0*549
Hydrogen -------- 0*499
Ammonia -------- 0*211
I ; Nitrogen -------. 0*035
100-000
Now, hi the fhmace, the oxygen introduced by the blast is consumed in the im-
mediate vicinity of the tuyere, being there converted into carbonic oxide, and the coal
loses all its gaseous products of distillation much above the point at which its com-
bustion commences, near in fact, the top of the furnace ; the fiiel with which the
blast comes into contact is therefore coke, and upon calculating the amount of car-
bonic oxide produced by the combustion of 68*925 per cent of carbon, and the
nitrogen of the air expended in the combustion, we get as the composition by volomc
of the gases escaping firom a furnace filled with Ga^ortii coal the following: —
Nitrogen - 62-423
Carbonic oxide --•..._ 33*163
Light carhuretted hydrogen ----- 2*527
Carbonic acid - - - - - - - 0*139
Condensed hydrocarbon - - - - -0*151
Sulphuretted hydrogen ----.. 0*091
Hydrogen -------- 1-431
Ammonia ....-••- 0*070
100*000
IRON. 553
- "With this preliminarj infbrmatioD, Bnnien proceeded to calonlate the modiflcation
of the gaseoiu miztnre occasioned bj the iDtrodaction into the farnace of iron ore
and limestone. The materials used for the production of 140 lbs. of pig-iron were : —
420 lbs. calcined iron ore ; 890 lbs. coal ; 170 lbs. limestone. From 100 parts of
the coal, 67*228 parts of coke were obtained ; but fh>m this most be deducted 2*68
ashea, and 1*18 carbon entering into combination with the iron ; which leaves as the
qoantity of carbon actually burnt into carbonic oxide before the tuyere 63 868 ; part
of this carbonic oxide undergoes oxidation into carbonic acid at the expense of the
oxygen in the oxide of iron which it reduces ; a further quantity of carbonic acid is
deriyed fhnn the limestone ; so that the gases returned to the mouth of the furnace by
the combustion of the 67*228 parts of coke, the reduction of the corresponding
quantity of ore, and the decomposition of limestone, consist oi^-
Nitrogen -.. -..•• 282*860
Carbonic acid •..-... 59*482
Carbonic oxide •-••••. 121*906
464*248
Add to this the products of the distillation of the coal, and we get the following as
the per-eentage compositions by weight and measure of the gases issuing from the
mouth of the Aimace.
Nitrogen - ^ - *
Carbonic acid - . • -
Carbonic oxide - . -
Light carbnretted hydrogen
Hydrogen- - - - .
Condensed hydrocarbon
Sulphuretted hydrogen
Anunonia - - . -
Bj weight.
By Tolama.
59*559
«>
- 60*907
12765
•
- 8*370
26-006
-
- 26-846
1*397
.
- 2*536
0078
•
- 1126
0*108
-
. 0112
0*053
.
- 0045
0054
.
- 0-058
100*000 100000
The ealcnlations of the quantity of heat capable of being realised in the Aimace by
the combustion of the ftimace gases are founded on the data on the heat of combustion
given in the posthumous papers of Dulong, according to which—
1 kilogramme or 15,444 grains of
Carbon burning to CO, heats 1 5,444 grains of water to 1 499<>C
* CO* 737 1<^
Carbonic oxide ---..-. 2502^
Hydrogen -. 84706**
Light carburetted hydrogen • . . . • 13469^
defiant gas 12322<>
Sulphuretted hydrogen - - - • . 4476^
Anunonia ........ 6060^
Using these numbers it is found that by the combustion of 100 of the furnace gases
there are generated from the
59*559 nitrogen .-••».. OOOO
12*765 carbonic acid • ^ • . . . oOOO
26*006 carbonic oxide -••••- 65067
1*397 carburetted hydrogen . • . • . 18826
0*078 hydrogen ----.-- 2704
0*108 olefiantgas 1331
0*053 sulphuretted hydrogen - . • . 238
0*034 ammonia • .. . - ^ • . 208
88374-
vnits of heat generated^ the unit being understood to mean the amount of heat neces-
sary to raise 1 kilogramme » 2*204 lbs." 15444 grains of water from 0^ centigrade, to
l^ cent The amount of heat realized in the furnace is limited to that produced by
the expenditure of the oxygen, corresponding to 59'559nitrogen in the production of
carbonic oxide ; this amounts to 20001 units *. hence follows the remarkable conclusion,
that in the furnace which was the subject of experiment, not less than 81*64 percent.
66i
moK.
oftheftielif kct bifae fbnn of combnMible matter itill H ta lue, vA (bn aij
IS'46 per cent, of the whole fiiel ia retlUed in t»njiag oat Am tToamti ii ibt
The tempcratBre vhich rtunild Im produced, by tie lUm« ef Ibe fttratoeguavbo
bunt vid> air, it fonad by dindtng (he nniu of heat, ris. 603-1* ariraig hta tht
oomboition of I kilograinme of (be gaae* by the Dumber TctnHing when ibe qoiliij
of the prodoet* of combnMion ii mnltipUed by their ipe^o beat (l-MSt iWIK):
we tbiu get the number 3D830F. i bat thii ii below (he tro^, iBtanaoh u dm ii u
aeMtnon of eomboatihle gaaee at the month of the flunacc, ariiiDg from the itotapD-
iitioii of the liquid product* of the diftillatioTt of the ooal in ita panage otst Ok nd
hot foeL Uaking proper correction for tbia, asd <i«ng nDmbera deriYcd from Mul
eiperimenta, MeMrs. Bonaen and FlaTflur calculated the lenperatnre of iht |im
when generated ander faToorable conditions at SS14° F^ and even thii mj b( in-
creased to 3G3!° F^ a tem|>eratnrc for abore that of cut iron, b; the uiig i blu
sufficiently hrated. Ifl atilising tbtse Waste Base*, care most be taken not to rdoic
them from the furnace till (hey really ate mule, OiU i*, until tbey hB*e doiit \lei
work in the ftimace ; it la obnons thai no comboitible matter conld be remored rnm
the lower regions of the furnace wilhont leriouily deranging the opetmtioni emenliil
to the reduction and tmelling of tbe ore. In order to remoTc the giK> effeclulli,
asd witliout iiijnry to tbe working of the fnmace, and in anch a Mau a) will perail
their combution to be effected with most advantage, tbe height of tbe funuci mat
be railed, the fall width of the mouth being retained, and the gaxee mast be willidnii
eufficienily tax below the mouth fbr them to be obtained dry, and also benoili i>*
point whixe they begin to enter into combnMion frMn contact wiA the itmnplMric
Various modes of collecting the gasel have been tried ; (he test seemi (o i* '*?'
adopted at Ebbw Vale, Sirbowy, and Cwm Celyn. A funnel-shaped CBSling, fqof' ^
its largest diameter to the throat of the foTDaee, prraects into the interior i depth <•
4 or 9 feel ; the orifloe at the bollom, fh)m 8 to B feet in diameter, is closed by » c«««l
easting, the npei upwards, from which a chain proceeds to a lerer h»Ting » '"?°'2
pt^seatthe other end. (See^.lOOO.) The materials are filled into the ftunie1-«»(*"
receptacle, and are charged into the flimace with a nniform diatribatiini, by lonnDK
the cone by means of suitable machinery, which again retnini it to its plw* ■J'"
emptied. The circular space around the fnnnel, inside the ftimace, fbnnt s cbmK'
ftrtlMl!MeptioaoftlMgMW,fttMni>IiiahtbeTU«MiiTcy«abTteick tmaiGli or inui
^pmgto ttu place of ooinbaitioii. Tbe whokairutgemcDtvLllbe dwrl; nadentood
B3^,
byM inipectiwiof th«accoinp«)jiiigplani,Fi>. lOOS, 1006, lOOT, 1008, 1009, kindly
faniiihed to the writer bj the propnelor of the Cwm Celyn and Btain* Iron Work*.
Fig. 1007 shows the plkn of extracting the gB«e« which ii tdopted at the Brymbo
Iron Workt. near Wrexham, the same being the patent of C. R Darby-
It consists of a Iftrge pipe or tnbe inaertcd into the middle of the top part of tbe
ftuuBCe, whieh descends a short distance down into the Tnaterisls, and it carried over
the top of the aide of the furnace in the form of a syphon, a contiQnatiiHi of which
pipe is taken to the boiiera, or hot air stoves, where the raa is bnrued in the tuual
way. The principal adTsntsige claimed by this method. Is that it pats no check oD
the free escape of the gases, by which the driving of the fornace is impeded, and the
Jnalily of the iron deteriorated. The patentee estimates tbe saving of ftiel with two
irnaces making 3'tO tons of iron per week, by applying the gas to tbe blast engine
boilers and hoi air stoves, at laoojl a year. Thus : — Consumption of fuel at engine
■Dd stoves eqnol to 7 cwts. of good cool per ton of iion, made at 3} per cwt. , is Si. 0^,,
say Sf. per ton on 13,480 tons, or 1348^
The causes of derangement in the working of blast ftimaccs when the gaiCT afa
drawn off to be otilised elsewhere, have been diligently slndied by Mr. George Panr,
of Ebbw Vde ; and he has kindly fnmished ns with the (bllowlng resnme of hi* ob-
servatioaa, for insertion in this article.
Tha murner in which the wute gwe* were fonneri? ooItecUd, w« by «iDkiof an
iroa tabe, 7 feet d««p, ioto Iha throat of ths fanuce, tlie dUmeter of the tube beii^
abont S feet leu than that of the throat, thu lesTing an aondar ipace of IB iaehet
betveea the iralla of the fomace and ihe iidea of the tube. From this apace the
gaiei vera Gloved to pau off bj Ihe preanire wftbin the furnace, through a pipe
vhich pc&atnled the riog and nalU. Wheo the Inbe «•■ kept fuU of mineral*, about
IRON. 657
I or J only of the gas escaped into the open air, the rest passing into the annalar
chamber ; and when this state of things was continued, those troablesome adhesions
of masses of semifused materials above and around the boshes, technically termed
" scaffolds," occurred, with the usual accompaniments of black cinder and inferior
iron. It is evident that when the tube was kept full of minerals, the contents acted as
a loose stopper to the current of hot gases forced op by pressnre from beneath, and
diverted them towards the annular space where there was no such resistance, thus
Imving the minerals in the central parts of the furnace insufficiently supplied with the
npwai^ current, and consequently with heat ; the minerals, on the other hand, sur-
rounding this cold central cone, were supplied with more than their usual quantity of
heat, as was evidenced by the burning of tuyeres, and by the destruction of the
brickwork in their neighbourhood. In this state of things, the ores in the external
portions of the furnace would become reduced and converted into grey metal ; while
those in the central portion would, according to the degree of deviation of the
ascending current of heated gases from them, descend to the point of fusion either
thoroughly deoxidised, and slightly carbonised, or possibly with a portion still in the
state of oxide, and mixing there with the properly reduced ores, enter into fusion with
them, producing a mixture of irons which must necessarily prove of inferior quality,
and a black cinder from the unreduced oxides. When the iron tube in the throat of
the furnace was kept only partially filled with minerals, much more gas escaped into
the open air, as might have been expected, and consequently more traversed the
central parts of the furnace ; and it was always observed that when that mode of filling
was adopted, the furnace worked much better : but then the object, vis. that of ecO'
nomising the gases, was not attained. Differently formed furnaces were found to be
disturbed in different degrees by this system of drawing off the gases: the old conical
narrow topped furnaces were affected very much less than the improved modern
domed top furnace of large capacity, from which all attempts to tiJ^e off any useAil
portion of the gases proved absolute ruin. It might be argued, that as the same
quantity of blast and fuel were used as heretofore, the ascending current of heated
gases ought to produce the same deoxidising and carbonising effect on the superin-
cumbent mass, whatever direction they might take in making their escape at the
upper region of the furnace ; for if the central part should not have been sufficiently
acted upon, the external anuulus would have more than its usual share of chemic^
influences. But when it is considered that iron is only capable of taking up a certain
quantity of carbon, and no more, it follows that after having received this dose, its
further exposure in the external parts of the furnace where the heated gases abound
can do nothing towards supplying the deficiency of carbon in the metal reduced in
the central part. From Uiese considerations it became evident, that no system of
drawing off the gases around the sides, whether by the insertion of an iron tube into
the throat, or by lateral openings through the walls into a chamber surrounding the
top of the furnace, can be adopted without more or less injury to its action ; and that
the only nnoljectionable mode would be to take the gases from a chamber above the
surihce of the minerals, thus equalising the pressure on the whole sectional area of
the mouth, and thereby allowing an equally free flow for the ascending current up
the middle, as well as up the sides of the furnace. By this method the whole of the
waste gases would become utilised, instead of a portion only, and the fhmaee would
be restored to its original state, inasmuch as the direction of the flow of heated gases
would not be interfered with by unequal resistance. To form this chamber, the fur-
nace must be covered in, and fed through a hopper, a plan long adopted at the Codner
Park Iron Works, with the supposed advantage of scattering the mmerals around the
sides of the furnace, and preventing their accumulating in the centre ; a conical charger
of this descripUon, but fixed in the throat of the blast furnace, was in use at the
Cyfiirtha Works more than half a century ago, the minerals being thrown by
baskets to the centre of the cone, and allowed to roll down to the sides of the furnace,
thus giving a cup form to the surface of the minerals, the larger lumps of course
rolling to the centre, and affording a freer passage in that direction for the upward
current. It was not, however, until January, 1851, that a trial was made, at the
Ebbw Vale Works, oif an apparatus of this description for collecting the gases. It
was then supplied to one of the old forms of conical furnace with a narrow top, and
the trial proved eminently successful, the furnace producing any quantity of iron re-
quired according to the burden, as usuaL Several other furnaces were similarly fur-
nished in and around the neighbourhood, and it was now thought that the principle of
taking off the gases from a <3iamber above the surface of the minerals, together with
the conical mode of charging, were the only indispensable conditions to success for all
furnaces ; and some even which were originally built too narrow at the mouth, were
jietually improved by the new method of charging, which did not allow of the sur*
558 IRON.
faces of the minerals rising higher than about 6 feet from the top ; thus giyiHg to the
furnace a diminished height, and as a consequence of its conical shape a wider
month. Farther experience, howerer, demonstrated the &Uacj of this general con-
clusion.
A large domed ftirnace was famished with the same kind of charging apparatus
which proved so successful in former instances, but to the astonishment of all it
turned out a complete failure, the same derangements occurring as in the former
cases, where a portion of the gases only was collected, by sinking a tube into the
throat Now this fomace could not^e filled to within 6 or 7 feet of the top, and at
that depth the diameter was 13 ft 6 in., owmg to the sharp sweep of the dome ; the
actual working Aimace was therefore 37 feet high, instead of 44 feet, with a mouth
13 ft 6 in., instead of 8 ft ; and as the minerals cannot lie so close against the
smooth sides of the walls as they do locked in each other in the more central region
of the furnace, a much freer discharge of the gases up the sides must take plaee ; and
on boring a hole through the side of the furnace, in Uie neighbourhood of the boshes,
it was found that 2 feet in, the coke and other minerals were at a white heat, but a
little further on towards the centre, lumps of black biasing coal were found, with
ironstone which had not even attained a red heat The charging apparatus was now
raised with the furnace 5 feet, and the minerals drawn up an indmed plane to the
charging cup, thus enabling it to be kept ftill to within a short distance of the old
mouUi, afker which the furnace worked as usual. That diminished height was not
the cause of the bad working of the furnace was afterwards proved, the furnace having
been blown out for repairs, and re-lined with brickwork, giving it that form and pro-
portion deemed necessary, from the experience gained ; the height being now only
87 feet instead of 44, and the diameter of the mouth 7 ft 6 in., or one half of that at
the boshes. The same charging apparatus which fiuled before, mounted 6 feet above
the mouth, was used, and Sie furnace has now been working uninterruptedly for 5
years, turning out as much as 160 tons of grey pig iron per week, or -when bardened
for white iron, 200 tons ; economising the whole o£ its gas, and as much under the
control of the manager as any furnace, either closed top or open top, can reasonably he
expected to be. It is dear, therefore, that the covering of the top haa nothing whatever
to do with the action of a furnace kept full to the mouth, and having the proper form
and proportions from that point downwards. The mouth must be understood to be
that part of the furnace which represents the mean height of the surface of the
minerals, and not the top of the masonry, and the question arises, wh-^t proportion
should that bear in diameter to the boshes or widest part, and what the latter diould
be with reference to height in order to secure a maximum economical effect on the
quality of the iron made, and on the yield of fueL This state of perfection can exist
only when the isothermal lines in the furnace are parallel to the horison. The tem-
perature of the minerals at any g^ven height above the tuyeres being the same tfarough
the whole horizontal sectional area at that height and consequently arriving at the
sone of fusion in an equally prepared states If the mouth of Uie furnace be too wide,
the heated gases have a greater tendency to pass up the sides than through the centre,
thus destroying the horizontality of the lines of equal temperature, and giving them
a curved form with the convex side downwards ; hence ores at different temperatures,
and of various stages of preparation, will occupy any ffiven horizontal sectional area
of the furnace ; these descending together and mixing in the zone of fusion, will pr»>
duce evils in proportion to the extent of the deflection of the curves from a horizontal
line. On the contrary, if the mouth of the furnace be too narrow in proportion to
the other parts, we may expect an undue portion of the gases to pass op the centre,
leaving the minerals around the sides comparatively unacted upon. It is easy to see
that evils of the same kind as before must exist here, the isothermal lines becoming
now concave downwards, instead of convex, giving as before, through any horizonCal
section of the furnace, ores at various temperatures, and at different degrees of deoxi^
dation or carburation, according to the depth which they may have attained in the
furnace. There are several instances of furnaces originally built with too narrow
tops, being greatly improved by widening them ; this may conveniently be done by
feedinfl them through a conical charger, which by lowerxngthesnrftceof the minerals
virtually increases the width of the mouth : on the other hand, furnaces having the
opposite defect of being too wide at the top, may be benefitted to some extent, provided
the walls are nearly perpendicular, or do not widen too rapidly downwards, by em-
ploying as large a cone as it is possible to work in the throat ; lor by the use of this
feeder, the minerals must fall close to the sides, and the larger lumps rdl to the axb
of the furnace, and so £BUiilitate the passage of the gases in that direction, besides
giving to the surface a concave or cup form, and consequently a diminished heig^
and resistance to the upward current in the middle. This principle of improving the
IRON.
559
1011
efaargiBg of saeli defactiye fttrnaees is •▼en carried oat to some extent In feeding open
top Aimaces where the gases are wasted. The charging plate is so placed as to
prevent the nose of the barrow fh)m projecting any distance into the ^rnaoe ; th*
minerals being thns discharged close to the edge, the larger lumps have a tendency to
roll oyer towards the centre, leaving the smaller at the ring walls, to cbsck the up-
ward current in that direction.
The aboTC considerations will materially assist in furnishing an answer to the oft
repeated and very important question, ** What form and proportions should a blast
fiimaee have to produce the best results in quality of iron, and in economy of fuel,
whedier worked on the open top principle, or enclosed fbr the purpose of utilising the
waste gases?** Experience has proved that when the mouth of the furnace is one
hifclf the diameter of the widest part, good work is obtained, and that any devia-
tion fVom that proprortion, if in excess, has been productive of great derangement
in its action. The height of the furnace should also bear a oertain proportion
to the greatest diameter, in order to secure an uniform flow ot the ascending current
through all its parts ; for if the widest part bear too great a relation to the height,
the boshes must necessarily be of a low angle, and consequently the minerals
around the sides near their top be at too great a distance out of the direct line of pas-
sage of the ascending current, and consequently remain only partially prepared for
fhsion.
The proportions recommended by Mr. Parry, and which have been practically
tested most satisfectorily in several instances, are as shown in fig, lOU. The month
b* h' one half the diameter of the widest part c c, and this should
not be at a less depth than its own diameter. The sides of
the furnace to this depth should be formed slightly dome-
fashioned, for the purpose of giving to that region a larger
capacity than would be obtained by a conical form. The
radius of the curve should be at right angles to the axts of
the furnace, and formed by a prolongation of the line repre-
senting the greatest diameter. When the radius is set at a
great angle with this line, which is often done to give greater
capacity to the domed part, the distortion produced by the
sharpness of the curve may leave a segment of the minerals c|
unacted upon by the gases in their passage to the mouth, apd
entail greater evils thfua would be compensated for by incre sed
capacity. The curve is continued below the widest part of
the furnace till it meets the top of the boshes d d, the angle
of which should not be less than 70^, and start from the
point of the tuyeres //. The depth also from the widest
part to the tu^lres should not be less than its own diameter
plus half the diameter of the tuydres. These proportions giye
a blast fiomaoe, of any determinate height fixed upon, the
largest possible capacity it is capable of receiving, while re-
maining free fh>m any distortion of form, likely to give a place for minerals to
lie out of tiie way of the action of the upward gaseous current ; when the height
exceeds the proportion to its greatest diameter indicated in the figure, an unnecessary
sacrifice in its capacity is the only loss entailed. The height above the mouth must
be regulated by the kind of hopper used for charging, where it is intended to carry off
the gases.
Doubtless when the true .principle of collecting these gases without injury to the
blast furnace becomes more generally known, attention will be directed to the
easiest and most convenient mode of introducing the minerals. The conical charger
has only one disadvantage, that namely of allowing a great waste of gas during the
charging ; probably some kind of revolving hopper may be contrived to remedy this
defect. It is of course assumed that the furnace is supplied with a proper quantity of
blast, and of a density proportionable to the diameter across the tuyeres, so as to
maintain a vigorous combustion of the tael to the very centre of the hearth, the top
of which is indicated by the letters e e, for unless this is attained, a cold eone of
minerals will remain in the centre, and produce derangements which no degree of
perfection in the fbrra of the ftimace in the higher region can remove.
Theory of the biast furnace. -^ Analyses of the gases fh>m a Aimace at Alfkreton in
Derbyshire, at various depths below the surface, gave to Messrs. Bunsen and Playfair
the results embodied in the subjoined table. The furnace was supplied with 80
oharges in the course of 24 hours, each charge consisting of 890 lbs. of coal, 420 lbs.
of calcined ironstone, and 170 lbs. of limestone, the product being 140 lbs. of ijig iron.
The gases were collected through a system of tubes of malleable iron, 1 inch in
560
IRON.
diameter, and were received in glaas tabes 4 inches long, and } of an incli in diameter.
The well known skill of M. Hansen as a gas analyst is a goaiantee of the aocnracj
of the determinations.
Compoiidon of the Giues taken from different depths in the Funuiee.
Nitrogen
Carbonic acid
CartMnlc oxide
Light carburetted 7
hydrogen i '
Hydrogen • •
Oleflantgas •
Cyanogen
I.
n.
IlL
IV.
V.
VI.
va
VIIL IX.
6 ft.
8 ft.
lift.
14 ft.
17 ft.
soft.
23 ft.
24 ft.
34 ft.
00-
37^
0«
3-18
0i»
1-34
65-35
7-77
»-97
3'75
6-73
0-43
0-00
64-77
9-42
90-24
8-23
6-49
0-85
000
63-57
9-41
2316
4-67
9-33
0-96
0-00
50.* 5
9-10
19*3
6-64
•12-42
157
0-00
65-49
12-43
18'77
4-31
7-62
1-38
0-00
60-46
10^
19-43
4-40
483
0-00
0-00
68-28
8-19
29-97
1-64
4-92
0*00
trace
56-75
10-08
SSr|9
2-33
5Ha
000
trace
From these analyses it appears : —
1. That at a depth of 34 feet from the top, within 2 feet 9 inches of the tn jdre, tlie
gas was entirely free from carbonic acid, bat contained an appreciable quantity of
cyanogen.
2. That the nitrogen is at a minimam at 14 feet
3. That carbaretted hydrogen is foand so low as 24 feet, indicating that at that
depth, coal must be undergoing the process of coking.
4. That hydrogen and olefiant gases are at a maximum at 14 feet.
5. That the proportions between the carbonic acid and carbonic oxide are irre-
gular, which is probably to be explained by the fact that water is decomposed as iti
Tapour passes through the layers of hot coaL
The average composition of the gases eTolred fh>m the materials used in the Usst
fhmace is somewhere between the two following numbers : —
Nitrogen 60*907
Carbonic acid 8-370
Carbonic oxide ----- 26-846
Light carburetted hydrogen - - - 2-536
Hydrogen ------ 1126
Oleflantgas - 0112
Sulphuretted hydrogen - - - - 0-045
Anunonia - • - - - - 0-058
lOOOOO
57'87S
9-823
24-049
2-743
4-972
0-392
0-035
0'U5
100*000
The proportion of nitrogen to oxygen as an ayerage deduced from these analyses
is 79*2 to 27. The product of the combustion of coal gives the same proportions as
those existing in atmospheric air, vis. 79*2 : 20-08. The excess of oxygen most
. therefore depend upon the carbonic acid of the limestone, and the oxygen of the ore
giTcn to carbon during the process of reduction. Now, as at a depth of 24 feet the
gas collected contained 27*6 and 26-5 oxygen to 79-2 nitrogen, it is held that at this
depth the gas must already have accumulated all the oxygen of the ore, and the car-
bonic acid of the limestone; and the conclusion is drawn that in hot blast furnaces fed
with coal, the reduction of the iron and the expulsion of the carbonic acid from the
limestone takes place in the boshes of the furnace. The exact region of the fnmace
in which the melting of the iron and the formation of slag are effected is not exactly
defined, but it is assumed that the point of fusion is at the top of the hearth. The
region of reduction in a furnace smelting with coal must be much lower than when the
fuel is coke or charcoal, because a large portion of the body of the furnace most be
taken up in the process of coking, and the temperature is thereby so depressed, that
it is sufficient neither for the reduction of the ore, nor for the expulsion of carbcmie
acid from the limestone.
The mean general results obtained by M. Ebelmen fh>m a charcoal furnace at
Clerval are given below. The methods of analysis adopted by this chemist were
altogether different from those employed by Messrs. Bunsen and Playfair. For
details we refer to his memoir in the Anmalee dee Mines^ vol. zix. p. 89, 1851.
IRON.
561
No. of analyst*
I.
II.
IIL
IV.
V.
VI.
VII.
D«pth below mouth
8 ft. 8 in.
8 ft. 8 In.
Oft. 9 in.
9 ft. 9 in.
19ft. 6in.
19 ft. 6 In.
27 ft.
Tymp,
Clarbonlc iirld •
Carbonic oxide
Hjdrogen
Carbarettad hjdro-
Nitrosen • •
12-01
24-65
5-19
0*93
67*22
11-95
23*85
4-81
1-88
58-56
4*14
31-56
304
0-84
60-92
4*28
81*34
2-77
0*77
60*89
0-49
85-05
106
0*36
68-04
85-47
1-09
0-81
6306
0-00
87-55
1*18
0-10
61-22
0-98
39*86
Q-n
0*25
68-17
Tbuls
100-00
100-00
lOOiX)
100*00
100-00
100-00
100-00
10000
Oi^gea, per 100 ni-
tnofcn ...
42*5
40-8
827
82-7
28-5
28*2
80-7
85-8
Carbon Tapoor, per
100 nitrofen -
83*8
81-7
29*6
29-6
88*6
28-5
30-7
35*9
L Oas taken a short time after the introduction of the charge : II. the same
taken a quarter of an hoar after charging : IIL gns collected through a cast-iron
tnbe fonr inches in diameter ; it rushed out with a noise and gaye a sheet of flame,
carrying with it particles of charcoal and dust : IV. gas coUected by boring the
masonry; it rushed out violently, burning with a blue coloured flame*. V. the
same taken an hour after : VL gas collected by boring the masonry at the back of
the ftimaOe about 3^ feet abOTe the tuyere ; it burnt with a white flame, giving off
fumes of oxide of sine ; it was collected through porcelain tubes : VII. gas collected
through gun-barrels lined with porcelain; it was evolved wiUi sufficient force to
project scoria ^i even cast-iron.
The ftimace was working with cold blast under a pressure of '44 inch of mercury.
The charges had the foUowmg composition : — Charcoal, 253 lbs. ; minerals (yarious),
397 lbs. ; limestone, 254 lbs. Thirty-two charges were driven in twenty-four hours ;
the furnace was stopped after cTerpr twenty charges ; the produce bemg 3970 lbs. of
black cast-iron ; the daily yield bemg about 6175 lbs.
The experiments show that while the carbonic acid progressively diminishes down-
wards, the carbonic oxide progressively increases, the former altogether disappearing
at a depth of 27 feet On examining the numbers representing the oxygen and
carbon referred to 100 nitrogen, it is seen that they diminish progressively to a depth
of 19 feet, the oxygen combined varying iVom 42*5 to 28*2. The proportion of
carbon in !he same ^itfie rises from 28*5 to 32*8 ; a result brought about as much by
the carbonic acid disengaged from the minerals as from the gaseous products of the
, distillation of the charcoaL It is seen that the reduction of the mineral is already
considerably advanced at the depth of 19} fdet ; and this, so to speak, wiUiout any
consumption of charcoal, but through the conversion of carbonic acid into carbonic
oxide. The hydrogen decreases as the carbonic oxide increases ; showiog that this
gas exercises no influence in the reduction of the ore.
The results obtained by M. Ebelmen from a coke fbrnace at Seraing were as
under : —
Na of experiment ...
I.
II.
IIL
IV.
V.
VL
Depth
1ft.
1ft.
4 ft.
9 ft.
10 ft.
10 ft.
12 ft.
45 ft.
Carbonic add ....
Carbonic oxide ...
Hydrogen » « • .
Cartraretted hydrogen -
Nitrogen* ....
11-39
28*61
2-71
o*-/o
57*06
11*39
28*93
3*04
*56*64"
9*85
28-06
0*97
1-48
69*64
1*54
83*88
0-69
1*43
62*46
1*08
85*2
1*72
0-33
61*67
113
85*85
208
0-29
61-15*
0*10
86-80
2*01
0-25
61*34
0-00
4505
OM
007
54-63
Totals ....
100*00
100-00
100-00
100*00
100-00
100*00
100-00
100 00
Oxygen, per 100 nitrogen
45*0
45^
40*0
29-6
30-2
80*6
29-9
41*2
Carbon vapoiir, per 100 nitrogen
35-2
35-7
83-0
29-4
29*6
80-0
299
41-3
L Oas obtained by plunging an iron tube, three centimetres in diameter, about
one ibot into the furnace : IL the same ; the gas burnt spontaneously : IV. two
consecutive analyses of the same gas : V. the gas was collected by an iron tube ;
y L gas eoUected by piercing the masonry two feet above the tuydres ; the gas was
accompanied by fumes of cyanide of potassium, but no cyanogen could be detaohed.
The furnace was 50 feet high ; the air was supplied urough two tuyeres, and yni
VoL.IL OO
S62 IRON.
heated to 2 1 2*^ ; it was driTen at the rate of 26,840 gallons per ninate under a prpoure
of *5 of mercury. The charges were composed of, onroasted minerals, 1434 lbs. ;
Ibrge cinders, 1434 lbs.; limestone, 948 lbs.; coke, 1765 lbs. The metal was mm
every twelve hours, and 17,500 lbs. of white crystalline cast-iron obtained, which was
run on thin plates and taken direotly to the pnddling-fiimaee. The yidd of the
mineral was 42 per cent, and the consumption of coke 1500 per 1000 of cast-iroo,
rising from 1800 to 2000 per 1000 of iron when the furnace was working for fomdry
iron.
The analyses show a rapid diminution of carbonic acid, and indicate that in die
upper regions of the furnace an energetic reduction of ore takes place by the oxide
of carbon under the influence of the high temperatnre of the ascending gase&.
Between one and nine feet the limestone is calcined. The reduction of the ore takes
place at this region by the conversion of carbonic oxide into carbonic add, without
change of Tolume and without consumption of carbon. The increase in the hydrogea
is too small to induce a supposition that aqueoos yaponr in decomposing can dissolve
any notable quantity of carbon. The gases collected at a depth of about IS feet
represent about the mean composition of the gaseous mixture ; from that point to a
depth of 45 feet, two-diirds of the total height of the furnace, the gases do not
sensibly Tary, and are composed almost entirely of carbonic oxide and nitrogen. At
12 feet the oxygen is to the nitrogen as 29*9 to 100 ; in atmospheric air it is as 26-3
to 100. The difference, 8*6, represents the oxygen arising from the reduction of the
silicates of iron constituting the forge cinders, which £o8 is seen to take place
between the tuyere and a depth of 12 feet These silicates are well known to be
decomposed with difficulty, but they are reduced at the high temperature preTailimg
in that zone of the furnace, and their reduction gives rise to a corresponding quantity
of carbonic oxide, to a consumption of fuel, and to a considerable absorption of latent
heat The other minerals are reduced higher up in the furnace, and this is common
to all coke furnaces, being due to the high temperature of the ascending gases, a
temperature much higher than exists in charcoal furnaces, a far larger quantity of
combustible being consumed. Hence it is that forge cinders can be sueoessimUy used
in coke furnaces; while in charcoal furnaces the introduction of small qnaotities
only alters the working of the furnace, makes the iron white, and corrodes rapidly
the walls of the furnace in consequence of the imperfect reduction.
From his eudiometrlc experiments on the gases from coke and charcoal furnaces,
Ebelmen deduces the following conclusions : —
1. That the amount of carburetted hydrogen is too small to exerose any influence
over the chemical phenomena of the furnace.
2. That the atmospheric air thrown into the furnace by the tuyere produces sue*
cessiyely carbonic acid and carbonic oxide, at a small distance from the opening.
The first of these reactions gives rise to an exceedingly high temperature ; the second,
on the contrary, causes a great absorption of latent heat, and a corresponding lower-
ing of the temperature of the gaseous current The limits of the zone qffiuMm bears
relation to the space in which the transformation of carbonic acid into carbouc oxide
takes place.
3. That the ascending current consisting of carbonic oxide and nitrogen, with a
little hydrogen, produces in ascending two distinct effects: it communicates one
part of its sensible heat to the materials of the descending column ; it becomes charged
with all the volatile products disengaged at different heights, and it reduces the oxide
of iron to the metallic state. Sometimes this transformation gives rise to an ineiease
in the quantity of carbonic oxide ; sometimes, on the contrary, it effecta the conTeruon
of carbonic oxide into carbonic acid without change of volume, and without eon-
bustion of fuel. Whenever the reduction of oxide of iron takes place with the
production of carbonic oxide, there is a consumption of fuel, and an absorption of
latent heat If is essential, therefore, to the good working of the furnace, that the
minerals should arrive completely reduced to that part where tlie temperature is suf-
ficiently elevated for the conversion of carbonic acid into carbonic oxide by contact
with carbon ; this condition is nearly always realised when the oxide of iron is in a
free state in the mineraL The reduction of the oxide when in combination with
silica requires, on the other hand, a high temperature, and it can only take place in
that zone of the furnace where the carbonic acid has completely disappeared.
4. That the zone where carbonic oxide exista slone is much more extended in coke
than in charcoal furnaces, and is nearer the mouth in the former than in Uie latter :
it falls lower, however, in the cylinder with hot blast, the quantity of heat remaining
the same.
5. That the volatile gaseous matters from the distillation of the charcoal pass into
the escape gases, and exert no influence on the reduction of the minerals.
The mutual relation of the carbonic acid and carbonic oxide, which is observable
IRON. sez
in the aoal^ses of Ebelmen, is not fooDd in those of Bonssn and PUjfiur; this is at-
tributed by Ebelmen to the circumstance that the latter chemists collected their gases
through narrow iron tribes, which, becoming intensely heated and partially choked
by the fragments of ore.and fuel introduced by the rapid stream of gas, so modified
the composition of the gases, that the analysis, howeyer carefully conducted, could not
represent accurately their real composition. Ebelmen collected his gases through
wide tubes, and from the lower parts of the ftunace, by piercing the solid masonry.
It is obvious, however, that none but very general conclusioas can be drawn from the
analysis of the furnace gases, in whatever way they may be collected, for their com-
position cannot be the same under all circumstances, the nature of the fuel, the pres-
sure of the blast, and (as Mr. Parry's experiments prove) the shape of the furoace
itself, must each exert an influence in modifying the circumstances which affect their
composition. Although, therefore, it is impossible to fix the precise region of Uie furnace
where the reduction of the oxide of iron begins to take place, that is, to define pre-
cisely the limits of the " zone of reduction,*' we may in considering the theory of the
production of crude iron divide the fomace into four sones. I. The cone of reduc-
tion; 2. The zone of carburation ; 8. The zone of fusion : 4. The zone of oxidation.
The zone of reduction will vary in extent, according as the fhmace is working with
coal or with coke ; with hot blast or with cold. The zone of carburation commences
just below the top of the bosses, the reduced metal in a soft and malleable state here
acquires carbon, its rapid sinking being retarded by the contraction which the sides
of the furnace begins to undergo from this point downwsrds. As the carbonised
metal passes through the zone of fusion it melts, togeUier with the earthy matters
which serve to protect it from the oxidising effects of the fourth zone, that of oxida-
tion, through which it passes in its passage to the crucible. If the temperature of
the zones of fusion and oxidation be not much higher than the melting point of spe-
cular iron, the metal in the crucible will be white, with little or no graphite; and if
the iron remain sufficiently long in the zone of carburation to take up the maximum
quantity of carbon, it will be bright iron. The reduction of silicon appears to take
place at about the melting temperature of specular iron: it exists therrfore in small
quantity in white iron, and in greatest abundance in the grey iron smelted from re-
fractory ores, which require a high temperature.
The proportion of carbonic acid in the gases obtained from different heights in a
furnace, has been studied by MM. E. Montefiore Levi and Dr. Emil Schmidt (Z«tV-
sckrijt dea Saten ItigenieurvereineM, 1852). They found that the zone from which this
gas is entirely absent is of Tery limited extent, for although it is not met with at a
height of 8 feet from the tuydre, it exists at 9 feet to the extent of 4*78 per cent,
above which point it diminishes up to 15 feet, where it is 0. From this point it
again increases, amounting at a height of 30 feet to 3'5 per cent. It then gradually
diminishes, until, at a point from 37 to 39 feet above the tuyere, it amounts to only
r69 or 1*91 per cent. ; after which it goes on increasing with rapidity and regularity
up to the furnace mouth. The carbonic acid existing in the furnace gases between
15 and 30 feet is referred by these chemists to the decomposition of the limestone used
as a flux ; and its gradual diminution above this point indicates a reaction of consi-
derable importance, that namely of the carbonic acid upon the ignited coke carbon
being taken up and carbonic oxide formed. Kow, the quantity of carbon taken up by
275 parts of carbonic acid to convert it into carbonic oxide, amounts to 75 parts, and as
in the furnace experimented with, 20,000 kilogrammes of limestone, containing about
8000 kilogrammes of carbonic acid were consumed ever^ 24 hours, a loss of fuel
equivalent to 2173 kilogrammes of carbon was daily occasioned by the conversion of
this carbonic acid into carbooic oxide, and this may be considered equivalent to 2500
kilogrammes of coke with 11 per cent of ash. The heat absorbed by the conversion
of the carbonic acid of the limestone into a gaseous state is found by calculation,
taking the specific heat of carbonic acid at 0*22, and the heating power of coke at
6000, to be equivalent to that developed by the combustion of 322 kilogrammes of
coke. Now it was demonstrated by Dulong that the Quantity of heat disengaged in
the conyersion of carbon into carbonic oxide is much less than that disengaged in the
conversion of carbonic oxide into carbonic acid, although the same quantity of oxygen
is required in both cases. The conversion of carbonic acid into carbonic oxide by
passing over ignited carbon, is essentially a twofold action ; a combination of carbon
with oxygen, and a decomposition of carbonic acid into carbonic oxide and oxygen : the
former is accompanied by development, the latter by absorption of heat ; the latter
preponderates to such an extent as to indicate a loss of temperature equivalent to the
heat developed by the combustion of 1609 kilogrammes of coke.
These considerations led the authors to employ burnt lime in working blast furnaces,
and thus to obTiate the loss of heat : the results were not at first satisfactory, the
management of the furnace being very difficulty and the slags black and pasty i but
oo2
564
IRON.
Bubsequentlj the working was regoUr and good, and tbe saTing of coke and tiu b-
crease of prodaction are stated to have been verj evident; moreover the raw iron vai
of better quality, and all the interior parts of the furnace, especially the tymp itoof,
remained in a much better state of preservation than when limestone was vsecL Tbe
following table shows the quantity of coke consumed for every 100 kilogrammei of
raw iron, and the production during six months. The figures in the first oolmnii refer
to the ftimace, in which limestone alone was used ; thie second eolomn to the stme
furnace, in which burnt lime alone was used ; and the third column to the fanaee
in which limestone was used for three months, and burnt lime for the aeit tbrce
months.
April -
May -
June -
July - - -
August
September -
Mean . . -
Average fh>m April
to June
Average fh>m July
to September -
Qoantitj of Coke in kilogrammM
cooMimcd for mwj 100 kilogrammM
raw iron.
I.
With
Lbneifiooe.
165
165
160
161
158f
153
160^
S.
With
burnt Iim«.
145
147
147i
146^
145
147}
146}
8.
WUh
Limestone.
Bedocdoo dnrinc V d^iihi
kUognmoMi.
163
159
164
With
bomt Lime.
149}
146
146
154}
162
I47i
1.
With
436,000
447,000
477,000
462,000
465,000
477,000
461,000
s.
With
hunt Line.
t
WU
Liaaim.
601,000
582,000
588,000
459,000
461,000
4^8,000
555,000
536,000
577,000
573,000
With
bontLtae
537,000
553,000
eoaooo
516,000
m •
469,000
-
563,000
The very regular and uniform results given in this table, show that by the ok of
burnt lime, the consumption of coke for every 100 kilogrammes of rawiroavu
reduced by 14 to 15} kilogrammes, while at the same time the production of in»
increased, within a certain period, as much as 22 to 24 per cent.
Hitherto the opinion of metallurgists, with regard to the use of burnt Iubi^ y|
rather un&vourable than otherwise, but since the above experiments were »«»« I*
Ougree). it has been employed with good results m England and Wales, sad at mca
as 12 kilogrammes of coke have, it is stated, been saved for every 100 kUogrsnunci «
limestone, which was replaced by 63 of burnt lime. . • .
Varietiu and chemical coMtitutum of cast iron, — In commerce there *'*y'"[ ^
cipal varieties of cast iron, known respectively as Nos. 1, 2, 3, and 4, or dark f^
bright grey, motUed, and white ; these terms, although convenient, do not, '^^T^ ^
indicate the intrinsic value of the iron thus denominated, as the variable ^^^^^
ore, fuel, and limestone may exercise such an influence on the feaxilting crm^uif^
to render a low denomination of one manufacturer of greater commercial raise
a higher denomination of other makers. The general characters of the ^^'^^^j,
are these: — No. 1. Colour, dark grey, in Uurge rounded grains, <>^*°*^,?""Qrfer,
near the commencement of the casting when the fhmace is in good ^^J /'^^gogl
and when an excess of carbon is present ; in flowing it appears pas^Tt *f^ , .j^p.
blue scintillations. It exhibits a snr&ce where crystalline vegetations "*^?r J^^f^
selves rapidl^r in very fine branches ; it congeals or fixes very slowly j n| ^
when cold, is smooth, concave, and often chai^fed with plumbago ; it naf ^^
moderate tenacity, is tender under the file, and susceptible of a dull P^^^ ^^
melted over again, it passes into Na 2, and forms the best castings. ^^,*Lp^|,ite
bright grey, of small-grained structure, and interspersed only with smsU g^ ^
lamins; possesses great tenacity, is easily filed, turned, and ^'^L'"*^J!!itore.
hammered to a certain extent ; does not r^ily crack from change of ^^ ^
No. S is a mixture of white and grey iron. On strongly mottled iron, ^iJrljSjrofl
spots of grey iron are found, interspersed in bright or flowery iron j ^^^'rV'^^hatt
exhibits white specks on a grey ground. In streaked iron, grey iron ^^^^ ^fj^jie
and below, and .bright iron in the middle, with strong demarcations. *^^^\^^ gyfo
iron varies flrom tin white to greyish white ; it is very brittle, cracking c>''v» ^
by vhange of temperature; it is extremely hard, sometimes even viOtt
IRON.
565
hmdened fteel, so that it will resiit the itrongest file, and icratchet glaii easily.
Fnetare sometime laminar, aometimet lamino-ndiating, sometimes finely spUatered,
sometimes dense and oonchoidaL As the fWustore ehanges from laminal to conchoidal,
the colour likewise Taries from white to greyish. Mean specific gravity, 7*5. Ex-
pands less than grey cast iron when heated, cannot he welded, hecanse it becomes
pasty at the yery lowest welding heat When heated to the melting point it does
not suddenly pass into the ftised state like grey pig iron, hat is converted before
fosing into a soft pasty mass. In this variety of pig iron the whole of the carbon is
united to the iron; it is never osed for casting, but always for oonTcrsion into
malleable iron. The bright iron obtained ttom spathic iron ore contains the largest
proportion of carbon (5*3 per cent according to Karsten). A white iron is always
the resolt of a derangement in the working of the fiimaee, though it by no means
follows that when the iron is white the ftimace most necessary be in a disordered
state, the presence of manganese, for example, has a tendency to make white cast
iron ; bat the quality may be excellent The white iron resulting from derangement
flows imperfectly, and darts out in casting abundance of white scintillations ; it fixes
very quickly, and on cooling exhibits on its surface irregular asperities, which make
it extremely rough ; it is exceedingly hard, thouffh it is easily broken; the fracture
being radiated and lamellar ; the bar iron it adSbrds is of inferior description. This kind
of iron is always produced when the Aimace is carrying a heavy burden of forge
cinders containmg sulphur and phosphorus.
Thus there are two distinct kmds of white cast iron : 1st That obtained from ores
containing a large proportion of manganese crystallising in large plates ; this variety
is highly prised for making steeL Sod. That resulting from a heavy mineral burden,
or ttim a general derangement of the ftamace, or firom the rapid chilling of fused grey
iron erystellising in smidl plates ; both are hard and brittle, the first more so than the
last Cast iron, which by slow cooling is grey, becomes white when it is cooled
rapidly; on the other hand, when white iron is melted and allowed to cool yery
gradually, a portion of the carbon crystidlises out as graphite, and grey cast iron is
produced.
In some iron works six yarieties of pig iron are recognised, which may be classified
thus: — 1. First foundry iron, large crystals; 2. Second foundry iron, large and
small crystals mixed ; 3. Dark grey, all small crystals ; 4. Bright grey ; 5. Mottled;
6. White, verging on mottled.
The sabjoined table exhibits the composition of some different varieties of Conti-
nental, English, and American crude irons. The methods of determining the various
elements which nearly idways accompany cast iron, are given at the end of this
article.
German
French
American
Silesian
Scotch
BnglUh
Wdih.
Dcwrip
a,
b.
c.
a.
e.
/.
f:
i.
J.
k.
/.
o.
P-
r.
Iran.
93-66
9S-S9
91*42
95*18
99-a9
94-87
96-85
96*56
91-45
90-75
99*68
99-06
99-76
89*45
94*10
96*97
98*55
91*99
86*00
91*99
94*71
Carbon,
0-48
8-78
1*44
i-oo"
•04
1-14
9-79
4-94
8-69
1-40
CSTDOBi
RCIS
8-85
1-99
9^1
8*40
0-18
807
1-50
1*90
9*69
9-60
9-80
VffS FlIM
2*49
8*80
4-00
4-98
4-17
1*91
PiKM-
pborai.
SvlphVT.
SUklB.
ManfS.
Total.
1-99
trace.
0-79
trace.
100*00
1*88
n
0-71
H
100-(i0
1*99
f»
8-91
>(
100-00
0*45
0-08
0*80
t.
99*86
0*88
8*75
1*80
t.
100-00
*99
trace.
1-80
»,
lOODO
•91
*01
•79
H
10000
•17
*06
*89
■f
99*89
•19
trace.
*75
8-38
100*64
8*96
««
*9S
900
99 88
i-ao
1*40
9*80
m ^
100*73
0*46
0*04
8-88
1-80
100-81
0-79
0*04
9-88
1*80
1(0 77
0-67
0*09
4*88
9-99
99*44
0-91
trace.
1-80
1*19
100-52
1-08
0*87
0*86
• m
100 00
1-66
0-14
1*85
fe •
100-00
01J7
0*01
(^91
8*65
98*86
0*06
0-00
0'69
8-40
99*81
0*07
0-01
0-21
4^11
99-86
1*84
9^
0*10
• m
100*00
Sp. tir.
7077
7-43
7 16
7159
7-M
767
7-53
7*6
a, Verp grew pit, from Leerhach tn the Harts, cold blast ; 6, MotUei Iron, from the royal works In
the HartSvOoM buut ; c. Normal gnj plv, from the lame workf, hot blast ; 4, Grej charcoal pig, cold
tilast ; «, white pif , from Flrmy, Tory snort and brittle } /, American grer pig, charcoal ; ^r, American
meiiied iron ; A, American charcoal, white iron ; /, Siiceian white charcoal Iron, Terj crvatuUoe ; J, The
same, bat less cryitalltne ; A, Groy Scotch oolu pjgj fkxmi the Calder iron works j /. Scotch odie. No. 8 pig
iron ; m, GU - - — - - - - - - . . . .... - -
from Dudley
pig iron, smc
Besides the sobstanoes enomerated in the ahoye table, other metals, such as copper,
arsenic, chromium, titanium, cobalt, sine, tin, aluminium, and the metals of the alkalies
oo3
566 IRON.
and alkaline eaiihs, are occasionally found in cmde iron, but very rarely in qnantities
Uiat can at all a£Pect the qualities of the product. The elements, the qnantitatiTe
estimation of which has been given in the above analyses, do, howerer, materially
modify the physical qualities of cast iron. We shall, therefore, offer a few obeerra-
tions on each.
1st Carbon. — Iron can take np any quantity of carbon np to a little over 5 per
cent., at which point it becomes saturated ; the compound thus formed is the wliute
crystalline pig or specular iron (i) (r) («)(0» '^l^en absolnlely pure its compositioii is
94*88 iron and 5*12 carbon, it is a tetra-carburet, Fe*C. The most highly carbnretted
iron which Faraday and Stodart could produce, consisted of iron 92*36 carbon 5*64.
There seems no reason for admitting, as some metallurgists have done, the existence of
a polycarburet of iron containing 18*3 per cent of carbon, inasmuch as iron containiag
under 6 per cent appears to be completely saturated. The specific gravity of pure
tetra-carburet of iron is 7 *66 ; it is the most fusible of all the carburets of iron, its
melting point being 1600^ Centigrade ; it is brittle and silver white, and crystalliies
in oblique prisms, which are frequently tabular. According to Gurlt the carburpt of
iron existing in grey pig is the octo-carbvret, FeK/, the crystals of which belong to the
regular or cubic system, but almost always appear in grey iron in the fonn of con-
fused octohedral groups. The specific gravity of pure octo-carburet of iron, accordiog
to the same authority is 7' 15, and its composition 97*33 iron and 2*63 carbon ; its ooloor
is iron grey, its hardness is inferior, and its fusibility less than that of specnlar iron ;
the groups of crystals often found in cavities in large castings are composed of this pe-
culiar carburet Gurlt very ingeniously endeavours to show that in grey pig-iron the
carbon of the octo-carburet is partially replaced by silwon, sidpkur, and pAoapAoms. and
the iron by manganese and other metals. In like manner the carbon of the tetra'car&yrei
may be partially replaced by silicon, phosphorus, or sulphur, the eliminated earbon
appearing in the form of graphite : the same decomposition is effected by heat, and
specular iron, if exposed to a temperature considerably above its fusing point, becomes
grey ; if cooled slowly, the graphite separates in large flakes, if rapidly, in minute
particles. Some metallurgists suppose that in grey cast iron, a portion only of the
iron is chemically united with carbon, the rest of the metal being dissolved in the
carbnretted compound in the form of malleable iron: we incline however to the opinioo
of Gurlt, that the whole mass of the iron is in a state of combination with the electro-
negatiye constituents, such as carbon, sulphur, phosphorus, and silicon. Thus in the
white pig-iron of heavy burden («), there is a deficiency of carbon, that element being
replaced by sulphur and phosphorus.
Karsten gives as the mean of several analyses, 3*5865 per cent as the quantity of
carbon in cast-iron smelted with charcoal from spathic ore. He states, that iron
coiHaining as little as 2*3 per cent, of carbon still retains the properties of cast-iron,
particularly the faculty of separating graphite when allowed to cool slowly. With
2 per cent of carbon iron is not forgeable, and scarcely so if it contain only 1*9 per
cent. With this quantity of carbon it is steel, though not of the weldable kind (cast
steel) ; even with so small a proportion of carbon as i '75 per cent it is weldable only
in a slight degree; the latter property increases as the hardness of the iron decreases.
An amount of from 1 *4 to 1*5 per cent of carbon in iron denotes the maximum of both
hardness and strength. Iron containing 0*5 per cent of carbon is a very soft steel,
and forms the boundary between the steel (i. e. iron which may yet be hardened) and
malleable or bar iron. These limits lie perceptibly higher if the iron be pore ; and
lower if it contain silicon, sulphur, and phosphorus.
The composition of the various carbides of iron, according to Berthier, is as under :
FeC3.
FeCa.
FeC.
Fe»C.
Te*C.
F**C.
Iron
0*600
0*690
0*819
0-899
0947
0*9643
Carbon -
0*400
0*310
0-183
0101
0*053
0-0357
In the blast fiimace, the reduced iron may take up carbon in two different ways ;
1. By immediate contact with the incandescent fuel ; and 2. By takmg carbon from
carbonic oxide ; thus Fe + 2C0 « FeC + C0». That iron decomposes carbonic
oxide is considered by Le Play and Laurent, to be proved by the following ex-
periment: pure oxide of iron and charcoal were heated in two sepantte porcctein
boats, placed in a glass tube ; the air in the tube furnished oxygen to the carbon ;
carbonic oxide was formed, which was converted into carbonic acid, at the expense
of the oxygen of the oxide of iron; the carbonic acid was again transformed into
carbonic oxide, by taking up a fresh quantity of carbon, which was again converted
into carbonic acid by taking oxygen fh)m the oxide of iron, and this went on until the
whole of the oxide of iron was reduced, the metallic iron then decomposed carbonic
oxide, producing carbonic acid and carbide of iron ; and this went on till a certain
quantity of carbon had combined with the iron, when the action ceased. If the
charcoal be very strongly ignited previous to the experiment, the carbonisation of tha
IRON. 567
iron does not ttke place, neither does pnre carbonic oxide earbonue iron when passed
OTcr the metal at a red heat : the effect in the experiment abore described maj
therefore be dne to the carbnretted hydrogen eroWed from the charcoal Iron begins
to take up carbon when heated only to the soften iDg point, the carbon gradually
penetrates the metal, converting it first into steel and Uien into cast-iron ; conversely
melted cast-iron gives up carbon to soft iron, ivhlch it converts into steel. When
vrhite iron (FeH)) is heated with acids, nearly the whole of the carbon is eliminated
in combination with hydro^n. Grey iron only gives up to hydrogen the carbon
which was chemically oombmed with the iron, the nnoombined carbon or graphite
remains unacted upon ) the dark spot produced upon grey iron by a drop of nitric
acid arises from this separation of graphite. For the amounts of carbon in the
diflkrent varieties of steel, see Stsbl.
PhogphontM. — In very few specimens of crude iron is this element wholly absent ;
when it exists in small quantities only, it is said rather to improve the iron for
castings, as it imparts to the metal the property of fusing tranquilly ; in a larger
proportion it weakens the iron. In like manner a very small quantity of phosphorus
hardens bar iron without materially infiaencing the other properties, but when it
exceeds *5 per cent it renders the bar brittle, cold-shnrt, as it is termed. According to
Schafhaentl, both cast-iron and steel are improved by phosphoms and by arsenic ; he
found the latter in the celebrated Dannemora iron, and in the Lowmoor iron, and
the former in the equally famous Russian (CGND) iron.
^af^AMT.— This element imparts to crude iron the property of becoming viscid, and
of solidifyinff quickly with cavities and air-bubbles. It is not certain to what extent,
or if at all, the presence of minute proportions of snlphor reduces either the tenacity
or the toughness of cast-iron of given quality in other respects. It is stated in the
Report of the Commission of Inquiry, as to the manufacture of ordnance on the con^
tinent, on the authority of Schiir and Mitscherlich, that in certain Swedish works
pjfriteB is thrown into the furnace with the other constituents of the charge, to produce
the fine grey mottled iron required for gun founding, and it is added that the effect
may be analogous to that of the oxidising flame in a reverberatory fUmace. It is
certain that sulphur possesses the property of concentrating carbon in iron : and as
mottled iron b a mixture of white and grey iron, it is not difficult to see how the
addition of pyrites may determine the formation of this variety of cast-iron in a fur*
once, which without it would produce grey iron only : but it is scarcely credible that
any intelligent founder would resort to such a method of making iron for casting
cannon, in which the hiffhest possible degree of tenacity is required. The fine grey
mottled iron, which firom its tenacity is known to be best fitted for large castings, is said
to he prepared without difficulty, by charging the furnace partly with roasted and partly
with raw ore, and so regulating the blast that the yield shall be regular, and the slag
nearly colourless ; these two ores, having different degrees of fusibility, are reduced
after different periods in the furnace, and hence afford one of tiiem grey, and the
other white iron, the result being, provided the minerals are properly proportioned, a
mottled iron, harder and more tenacious than grey iron, obtained by mixing or by
smelting in the cupola. It is desirable that the temperature of the furnace should be
kept as low as possible, the production of dark grey graphitic iron resulting always
from intensity of heat
When sulphur is melted with iron containing the largest amount of chemically com-
bined carbon, sulphuret of iron is formed on the surface ; underneath a layer of
graphite, and beneath that, a layer of iron with the maximum of carbon : and when
greif iron containing 3'81 per cent of graphite is melted with sulphur, whiie iron,
containing iron 94*03, combined carbon 4'98, and no graphite, is form^ The tendency
of sulphurous ores to produce white metal in their treatment in the blast furnace, has
long been known ; it was supposed that this was occasioned by the too great fusibility
which the sulphur gave to the cast iron, but ores containing large proportions of phos-
phoric acid will produce very grey iron, notwithstanding their fusibility, so that this
explanation does not serve ; the experiments above described point to the true reason.
The sulphur present in the ore (if as sulphuric acid reduced in the Aimace) enters
into combination with the iron, displacing a corresponding proportion of carbon, which
becomes concentrated in Uie remainder of the metal, forming white iron. To guard
against this, and in order to obtain a metal which shall contain a minmmh amount of
sulphur, the slags should contain the maximum amount of lime, M. Berthier having
shown that this earth decomposes sulphuret of iron at a high temperature, in the
presence of carbon. Ji, Janoyer states, that the proportion of lime and silica in the
slag may be as 54 to 36 ; it is doubtful whether snch a highly basic cinder would be
sufficiently fusible. Direct experiments, however, have shown that the amount of
sulphur in cast-iron diminbhes in proportion as the amount of lime in the slag in*
CKaaes. A still better flux is oxide of manganese, and it is found that when the
o o 4
568 IRON.
manganiferoos spathoee ore eonstitates put of the burden of the ftonaoe, solpliar
almost entirely diaappears from the crude iron. M. Janoyer believes that he has
proved ezperimentallj, that the whitening of east-iron smelted from sulphurous ores^
is due, in part at least, to the subtraction of a portion of its carbon, and its volati-
lisation in the form of sulphuret of carbon, by which the temperature of the fornaee
is lowered ; but his experiments on this point require eonfirmation. The presenee of
a very small quantity of sulphur acts very injuriously upon bar iron, so small a pro-
portion as |g}gg rendering the metal ** hot short," that is, incapable of being worked at
a red-heat under the hammer. If the quantity of sulphur in the crude iron exceeds
0*4 per cent, it is scarcely posuble to manufiicture it into sood wrought iron.
SiUeon. — Like carbon this element enters into combination with iron in all propor-
tions up to as high as 8 per cent The largest quantity found by Karsten in pig-
iron was 3*46 per cent, but in the above table a specimen (a) is quoted from Coal-
brook Dfde containing 4*88 per cent: and we hare lately found it in a sample of
Nova Scotia iron as high as 5*8 per cent Generally speakug, grey cast-iron contains
more silicon than white, and the greater the quantity of graphite in the crude iron the
larger the amount of silicon, because Uie higher the temperature of the furnace ; but
this again will depend materially on the quality of the coal, fhmi the ash of which the
silicon is probably principally derived. A clean strong coal yielding a small per
centage of ash fhmishes a cast-iron with less silicon than an inferior coal, the minenl
burden being the same. Pig-iron smelted with hot blast contains more silicon thsa
when the blast is cold, because of the higher temperature which prevails in the fiuioa
cone of the furnace. Some analyses illustrating this fact have been already given.
According to the experiments of MM. Janoyer and Oauthier the amount of silicon
in hot blitft cast-iron ma^ be greatiy influenced by varying the proportion of lime-
stone in the fiimace. Pig-ifon obtuned with a charge yielding a cinder in which the
lime and alumina were to the silica as 7 is to 10, had little stren^, breaking readily,
and analysis showed that it contained 3 per cent of sUicon. By mcreasing the amount
of lime in the charge, so as to obtain a cinder in which the bases were to the silica as
8 is to 10, and at the same time employing a blast of the highest attainable temperature,
tike iron produced had a much g^reater strength. When the proportion of bases to
silica in the cinder was as 20 is to 19, the iron contained only an inappreciable amount
of silicon, and the strength was increased in the proportion of 65 to 45. When the
maximum quantity of lime was used the consumption of fuel was on the avenge in-
creased to the extent of 6 per cent
On reading the above account of the experiments of Messrs. Janoyer and Ganthier,
the writer of this article induced the fhmace manager of the Blaina Iron Works to
increase the yields of lime on one oi his furnaces to as great an extent as in his judg-
ment it would bear, and when the fiimace was under the full influence of the excess
of flux to forward him samples of the my pig for andysis. The following resolu
show that, contrary to the statement of MM. Janoyer and Ganthier, no advantage,
as regards a diminution in the amount of silicon, was hereby obtained, the proportion
of that element being not perceptibly altered, though there is a slight diminution
observable in the percentage of siUphnr.
Gr^ pig, with uiual Onj plm, with extn
burden of lime. burden of Uid«l
Sulphur .... 0*067 ... - 0*045
Silicon .... 2*900 .... 2*930
As the presence of silicon in pig-iron affects in a remarkable degree the yield as
well as the strength of puddled iMirs, it is of importance that this element should be
removed as effectaally as possible by a refining process before the crude iron is sub-
mitted to the puddling process. Pigs with 8 per cent of silicon give about 6 per
cent of silica, and this requires somewhere about 12 per cent of iron to form a cinder
sufficiently fluid to allow the puddled iron to become aggregated into balls; this can
of course be obtained only by ^ariiin^ that amount of iron m the puddling furnace
after the expulsion of the carbon, and while the mass is in a powdery state. This
powdery mass is composed of small granules of iron mixed up with a ^ney inAisible
cinder* The puddler turns over this mass repeatedly to expose the iron to the oxidising
influence of the fhmace ; the silica now takmg up sufficient oxide of iron to give it
fluidity begins to separate from the iron, and forms a pool at the bottom. After some
time the puddler, finding the mass of cinder accumulating pretty fast, makes the first
attempt to '* baU up.** la order to sutc as much iron as possible, he keeps the damper
down and works the powdery mass at as low a red heat as possible. The balls, even
when made, will not bear much heat under the hammer without fidling to pieces,
hence an imperfisct weld in the hammered mass and rolled bar is the result, and
although the iron may be chemically pure it is deficient in strength. By protracting
the process and wasting more iron, there is no doubt but that the ircm might be im-
mON. 669
proved, for the cinder would become richer in oxide, more fluid, and oomequently
offer less resisUnce to a perfect weld. Iron, on the contrary, with a small percentage
of silicon may be ** balled up " directly it is *' dried," and Uie short time required for
that operation can be conducted at the highest heat of the furnace. A good welding
of the mass is the consequence: such iron is ttnmg^ and the labour of the puddler in
obtaining it is much less than in the former case. Every pound of silica must have
twice its weight of iron to form a cmder sufficiently rich in oxide to allow the
particles of iron to become properiy agglutinated. Such being the influence of
silicon on both the yield and the strength of wrought iron, and such being the waste
attendant on its removal in the refinery, it becomes an object of much practical im-
portance to prevent as fkr as possible the formation of a silicide of iron in the blast
furnace, and the observations of MM. Janoyer and Oauthier on this point require
careftil verification.
MaMgane$€> — The presence of this element in pi^-iron does not appear to exert
much influence either fbr good or for bad on the qcuihty of the metal, and even when
it exists in quantity amounting to 4 or 5 per cent in the crude iron, it disappears
almost entirely dnnng the conversion of the cast-iron into wrought or malleable. It
has already been observed that the cinder from iron smelted from manganiferous ores
contains, generally speaking, more sulphur than slags or cinders frtmi iron ores con-
taining no manganese. We have had numerous opportunities of confirming this, and
have uerefore on this account alone attached much importance to the existence of
manganese in iron ores; but our attention has more recently been directed to another
point which we think especially worth of notice of iron manufacturers, namely, to
the almost perfect removal of phosphorus from pi^-iron containing a very large pro-
portion of that element, and at the same time a high* percentage of manganese. As
our experiments on this important point are still in progress, we shall merely here
quote a few in illustration of the purifying action we have alluded to.
Iron made fi^m a highly phosphorised ore containing no manganese : —
PhMpbomt
percent.
Pig 8030
Paddled bar 0*838
Rough down bar ....... 0*572
The finished bar was cold short in the highest decree, it was in &ct nearly worthless.
Iron made from a highly phosphorised ore oontaming a large per-centage of man-
ganese.
PbotphonM. ManguiaM.
Pig - - - . 2*60 - - - - 7*20
Paddled bar . - - 0*30 - - . -Ift.,^
Do. ... 0*20 - - . -r^^
Finished bar - - - 0*11
The iron was carefully watched during the puddling process. It melted very thin,
and took rather more work than usual ; as soon as the boiling commenced it was very
violent, the metal forcing itself out of the door hole until it was checked. When it
** came to nature,** as the workmen term it, it worked beautifully and stood any amount
of heat, in fact the heat could with difficulty be raised to the requisite degree. The
yield was 22 c wts. 2 qfs. 24 lbs. of pig to produce one ton (of 20 cwts.) of puddled bar ;
this is about the vield of good mine iron when properly puddled. The finished bar
exhibited none of the cold short quality, it was exceedingly ductile, indeed excellent
horseshoes were made fh>m it The puddling cinder had £he following composition :—
Silica 8*240
Protoxide of iron -.----- 70*480
Oxide of manganese ...... 12*800
Phosphoric acid ....... 7*660
Sulphur 'MS
99*715
Other observations have shown that highly manganiferous pig (without phos«
phorus) is puddled with difficulty, and sometimes with considerable waste, so that the
advantages of an alloy of manganese would seem to be confined to those varieties of
crude iron into the composition of which phosphorus largely enters.
The Omnertion of Crude or Carbwrised from uito ifaZSa6& /roM. — This is effected
by one or more operations, which are necessarily of an oxidising nature, the object
being to eliminate from the cast iron the carbon in the form of carbonic oxide gas,
and the silicon, sulphur, photqdiorus, and oUier foreign bodies in the form of oxidised
670 moN.
prodnett, which [mh rither partially or wholl; into tha teorin or cinder*. The pic-
iron ja either labjected lo ■ prelimiaary decvbaislioD in the ozidiiing blut beuUi,
or " t¥fln«r]r.* sod the operatioD thus coinniencrd Bftenrards completed in the oit-
diting air-furnaee, or " paddling furnace ; " or the complete eoaTenion of the crude
iron is effected bj ooe operation in the puddling furnace, b; the proce>sca)l«i "boiling."
It is uid {Btackictlt) thit. at several worki abroad, the attempt to arrest the progif
of decarburalioD id the paddling or boiling furnace at that point in irhich the eon-
Tersion has proceeded onl; so fkr aa to leave the iron in the state of steel, or nb-
cnrburet. has been sncceesfnl, and that a valuable natural or puddled steel, not reqtiiriBg
cementation berore conversion into refined or east ateel, has been the result.
Engtith Method ofr^finbig. — The finery fomace is eomposed of a bodj of briek-
vork. about 9 feet square, rising but little above the surface of the gronnd. The
hearth, the bottom of irhich is of milblone grit, placed in the middle, is 3^ feet dtepi
it is rectangular, being in general 3 feet bj S, with its greatest aide parallel to the fare
of the Injures, and it is made of cast iron in four plates. On the side of the tnvem
there is a single brick wall, on the three aides sheet iron doors are placed, to prevent
the external air ftom cooling the metal, which is almost always worked nnder an
open shed or in the open air, but never in a space surrounded by walls. The chimney,
from 15 lo 18 feet high, is supported upon four colnmns of cast iron ; in lintel is 4 feet
above the level of the hearth, in order thai the labourers may work without mtraint
The air ii supplied by the blowing cylinders which sapplythe blast flimace, and enter
the hearth through G tuyeres, so arranged that the current issuing from Iboae oo the
opposite sides of the crucible are not diapoaed in the same plane. These tDy^rrs. like
those in the furnaces in which cast iron is made, are provided with double caaingi.
through wbicb a current of cold water is constantly flowing, aad each pipe ia famiahed
with a suitable stop valve for regulating the volume of the blast. The tny^res are
pUced at the height of the lip of the craable or hearth, and are inclined towards the
bottom, at an angle of from 35° to 30°, «o as to point upon the bath of melted metal
as it flows. The quantity of air blown into the finerlea is conalderable. being nearly
400 cubic f^t per minute for each finery. The ground plan of a finery is shown in
JV^.IOta, A being the beartb, b the tapping hole, a the chill mould, and a a a a a a the
noirlea of the tuyi^rea The operation of re-
fining crude iron is condncted as follows- A
Gre is lit in the centre of the bearth, which is
first urged by a gentle blast ; a charge of pig,
J about 3 tons, is then laid on, and the whole i*
covered np dome-form with a heap of coke ;
the full power of the btsit is now turned oo,
, the cast iron melts, and flowing dowu gradually
collects in the crucible, more coke being added
as the first quantity burns away, Tlic ope-
a ra^on proceeds by itself, the melted metal
is not stirred about as in some modes of re-
finery, and the temperature is always kep«
high enough to preserve the metal liquid.
During this stage the coals are observed con-
^natly heaving up. tr movement due in part
to the action of the blast, bat in part to
an expansion caused ia the metal by the dis-
charge of carbonic oxide gas. When all the
pig-iron is collected at the bottom of the hearth,
which happens in sboat two hoars, it is blown
vigoronsly for some time longer, the tap-hole ia
opened, and tbe^iw metal runs out with the slag into the chill mould, or pit. aa it is
called, which has been pniviotisly washed with a thin clay liquid, to prevent ihe refined
metal from adhering to its snrfkce. The chill motdd is in a proloufalian of the
tapping bole; it ia a heavy cost iron trough, about 10 feet long, 3 feel broad, and 3 to
S} inches deep. The slag, from its inferior specific gravity, forms a crust on the
surface of the metal : its separation is facilitated by throwing cold water in large
quantities on the fluid mass immediately that the entire charge has left the refinery.
This sudden chUlingof the metal makes it exceedingly brittle, to that it can be broken
into smaller pieces by heavy hammers, for the subsequent operation of puddling. The
refined metal is very white, hard, and brittle, and possesses in general a fibrous ra-
diated texture i or sometimes a cellular, iaclnding a considerable number of small
spherical cavities, like a decomposed amygdaloid rock. The loss of iron in the re-
finery process is very large, varying trota 10 to SO per cent In the Welsh iron worki,
t ton of while iron takes Aram 1 j lo 3 hours to refine, the consumption of coke beinf
IRON. «71
from 6 to 8 cvt«., and the lost about 3 ewtt. Orey Iron takes from 7 to 9 cvts. of
coke per ton, the time required to reflne being from S| to 3 boors, and the loss of iron
per ten 4 cwt The pig-iron to be decarbarised in the refinery is frequently mixed
with rich silicates (forge cinders), and occasionally with oxides of iron, the object
being to protect the melted metal in some degree from the oxidising effects of the
blast, and to react on the carbon which it eontams. The quantity employed depends
on the degree to which the pig-iron is carburised. The crude iron, from which
wrought iron of the best quality is produced, is that possessing a medium degree of
carboration, or what is generally termed grey pig-iron. White iron, which possesses
an inferior d^preeof fluidity to gre^ pig-iron, and which comes as it is termed more ra-
pidly to nature, is that quality which is most generally employed in the manufacture
of wrought iroD, especially when the conrersion is effected in the single operation of
boiling in the puddling furnace ; but this species of pig-iron being the result of im-
perfect re- actions in smelting, is always more impure than grey iron obtained from
the same materials, and does not produce wrought iron of the best quality.
The coke employed in the refinery should be as free as possible from shale, and
should contain only a low percentage of ash ; it should especially be free from sul-
phuret of iron, which it often oontains in considerable quantity, as it is found that
nearly the whole of this sulphuret enters into combination with the metal« and does
not pass off in the slags.
Refineries are sometimes worked on hot fluid iron, run direct from the hearth of
the blast fiirnace, a considerable saving, both of time and fuel, being hereby effected.
Various proposals have been patented for the employment of fluxes to assist in the re-
moval of the impurities of cast iron, both in the refining and puddling furnaces. Thus Mr.
Hampton patented, in 1855, a flux, prepared by slakjng quick lime with the solution of
an alkali, or alkaline salt MM. Du Motay and Fontaine propose, in a patent secured in
1856, to purify and decarbonise iron in the refining and puddling firnaee, by the em-
plojinent effluxes prepared from the scorice of the puddling furnace, from oxides of iron
and silicates or carbonates of alkalies, or other bases. Mr. Pope ( 1 856) proposes to add
the residoe obtained b^ the distillation of Boghead or Torbane mineral, to such fuel as is
employed in the refinmg of iron. Mr. Sanderson, of Sheffield (1855), employed for the
refining of iron such substances as sulphate of iron, capable of disengaging oxygen
or other elements, which will act upon the djUoium, aluminum, &C., contained in the
metal These and various other schemes have Men suggested with the object of lessening
the enormous waste which pig-iron undei^goes on its passage through the refinery; for as
the process is at present conducted, the partial elimination of the carbon, sulphur, phos-
phorus, &c, is only effected at the expense of a large quantity of iron, which is oxidised
by the blast, and passes in the form of silicate into the slag ; the desideratum is the dis-
covery of some method of reducing the oxide of iron, and substituting for it some other
base, which will form with silica a sidficiently fusible silicate. Mr. Black well suggests
that the decarbnration <^pig iron might be effected by remelting it in a cupola furnace,
either alone, or with minerals containing nearly pure oxides of iron ; the oxide of iron
would be reduced by the carbon of the pig-iron, while the silicates 4f the fhel, with
the silica, alumina, and other easily oxidisable alloys eliminated from the crude
iron, would be separated in the form of fusible earthy glass. The employment of
steam as a purifying a^nt for crude iron has been patented b^ several persons. Mr.
NasmyUi in 1854 obtained a patent for the treatment of iron m the puddling furnace
with a current of steam, which being introduced into the lower part of the iron, passes
upwards, and meeting with the highlyheated metal undergoes decomposition, both
elements acting as purifying agents. The steam employed is at a pressure of about 5
pounds per square inch, and passes into the metal through a species of hollow rabble,
the workman moving this about in the fused metal until the mass begins to thicken,
which occurs in from five to eight minutes after the introduction of the steam ; the
steam pipe is then removed and the puddling finished as usuaL
The i^vantages are said to consist in the time saved at each heat or puddling
operation (frx>m ten to fifteen minutes) ; the very effective purification of the metal ;
and tiie possibility of treating highly carbonised pig-iron at once in the puddling
furnace, ^e preliminary refining being tiius avoided. In October 1855, lir. Bessemer
patented a somewhat similar process for the conversion of iron into steel, the steam
highly heated, or a mixture ol air and steam, being forced through the liquid iron
ran from the furnace into skittle pots, steam being used only at an early stage of the
process, and the treatment finished with heated air. In the early part of the same year
Mr. Idbutien of New Jersey obtained a patent for a partial purification of crude iron,
by causing air or steam to pass up through the liquid metal, as it flows along gutters
from the top hole of die furnace or finery forge ; and he subsequently proposed to include
with the air or steam, other purifying agent^ such as chlorine, hydro^n, and coal gas,
oxides o£ manganese, and tifke, &o. Other methods of treating crude iron with air and
612 IRON.
■team were mtde the sabjeets of patents by Mr. Bettemer in December 1855 and January
1856. In October a patent for the employment of steam in admixture with cold blast io
the imelting famace and fining forge, vas obtained by Messrs. Armitage and Lee, of
Leeds, and in Angust a patent was obtained by Mr. George Parry, of the Ebbw Vale Inw
Works, for the purification of iron by means of highly heated steam. The floid iron
is allowed to run into a reyerberatory famace preriously heated, and the steam is
made to impinge upon it from sereral tay^res, or to pass tluongh the metaL Steel ii
to be obtained by treating hi||[hly carbnretted iron with the steam, and then mnning
it into water, and fusing it with the addition of purifying agents, or adding to it in
the furnace a small quantity of cla^, and afterwards abQut 10 or 1 5 per cent, of calcined
spathose ore. Mr. Parry obserymg that when steam was sent through the molten
iron, as in Mr. Nasmyth s process, the iron quickly solidified, conceiTcd the idea of
communicating a high degree of heat to the steam by raising the steam pipe a couple
of inches abOTC the snr&ce of the metal, so that it might be exposed to the intensely
heated atmosphere of the fhmace ; and also of inclining the jet at an angle of 45^, m
as to giTc the molten mass a motion round the furnace while the pipe was maintained
in the same position at a little distance beyond the centre : when this was done, in a
few minutes the iron began to boil yiolently, the rotatory motion of the fluid bringing
every part of it successiyely into contact with the highly heated mixture of steam and
atmospheric air, and no solidification taking place. Having thus ascertained the pro-
per way of using steam as a refining agent, it occurred to Mr. Parry that, as the pre-
sence of silicon in the pigs for puddling affects in a remarkable degree the yield of
iron, as weU as its strength, it is a matter of consequence that this element should be
removed as completely as possible previous to the puddling operation ; the steaming
of the iron would probably therefore be more profitably applied in the refinery than in
the puddling furnace. Pig iron containins 3 per cent of silicon gives 6 per cent of
silica, which, to fbrm a cinder sufllciently nuid to allow the balling up of the iron,
would require fh>m 10 to 12 per cent, of iron ; and this can, of course, only be obtained
by burning that amount of iron in the puddling fbmace, aftsr the expulsion of the
carbon, and while the mass is in a powdery state. The superheated steam is injected
on the surface of the iron in the refinery by water tuyeres, similar to those us^ for
hot blast at smelting furnaces ; they are inclined at an angle of abont 45^ ; some are
inserted at each side of the door of the furnace, and are pointed so as to cross each
other, and give the iron a circulating motion in the fdmace. The tuyeres are ttoax
1 to ( an inch in diameter ; a little oxide of iron or silicate in a state of fusion on the
surface of the iron accelerates the action, as in common refineries, and increases the
yield of inetal, bat to a much greater extent than when blasts of air are used. The
steam having been turned on, the mass of iron commences circulatinf around the in^
clined tuydres, and soon begins to boil, and the action is kept uniform by regu-
lating the flow of the steam. The most impure oxides of iron may be used in this
process, such as tap cinder or hammer slag fh>m puddling fhmaces, without injury to
the quality of the refined metal made ; the large quantities of sulphur and phosphorus
which they contain being effectually removed by the detei^gent action of the heated
steam. When 4 cwt of cinders are used to the ton of pig, 20 cwt of metal may be
drawn, the impurities in the pig being replaced by refined iron from the cinders.
We have had several opportunities of witnessing this beautiful refining process at the
Ebbw Vale Iron Works, and have made the following analysis of the cinders and
metal which fully bear out the above statemento: —
Fig Iron. Refined metal.
Graphite ..... 2*40 ... 0*30
Silicon 2-68- . - 0*32
. Slag 0-68 ... 0-00
Sulphur 0-22 - - - 018
Phosphorus .... 0'13 ... 0*09
Manganese- .... 0*86 ... 0*24
Forge dnden thrown Cinder nm oat of
loto the reflaery. the reSnerj.
Sulphur 1*34 - - - 016
Phosphoric acid - - - 2*06 - - - 0*129
A ton of grey iron may be refined hj steam in half an hoar, using seven jets of
steam ] of an inch in diameter, and with a pressure of firom 80 to 40lba. ; the tem-
perature of the steam being from 600^ to 700^ F., the orifices of the tuyeres being
2 or 3 inches above the surfiice of the iron. As the fluidity of the metal dependa
upon the heat which it is receiving from the combustion of the fuel in the grate, mad not
on any generated in it by the action of the steam, it is evident that the supp^ of the latter
in a given time must not exceed a certain limit, or the temperatore of the fluid iron
will become reduced below that of the fhmace. This however partly regolatca itsd^
IRON.
673
aod docf not require moeh nicety in tbe management, for, if too mnob steam be
giTen, the ebullition becomei io Tiolent, as to cause the cinders to flow orer the
bridges, giving notice to the refiner to slack his blast The ** forge cinders " used in
the steam refinery contain 66 per cent of iron ; the ** run out** cinder contains only
2G ; 40 per cent of iron, or thereabouts, have therefore been converted into refined
metal, and the resulting cinder is as pure as the ordinary Welsh mine, with its yield
of 25 per cent of iron. The following is the result of one week's work of the steam
refinery: — cwu qn. ita.
Pigs used 396 0 15
Metal made 398 8 i
Loss
Tield
14
20 0 14
The quantity of cinder (puddling) used was 3^ cwt per ton of pig. When 1 J cwt.
of cinders were used to 1 ton of pig, the yield was xnTariably 80 cwt over a make of
about 100 tons.
Befbumg Inf goM {German metkod),'^The most simple form of gas rererberatory
fbmaoe is that known as Eck's ftimaoe, which is employed at the government works
of Gleiwits and Konigshiitte, for refining iron made on the spot. The following
description and plan of this fhmace is extracted firom a report to the secretary of
state for war, f^m the superintendent of the Royal Gun ketones, Colonel Wilmot,
R. A., and the chemist of the War Department, Professor Abel.
The gas generator (which replaces the fire-place of the ordinary reverberatory
fbmaoe) is an oblong chamber, the width of which is 3 feet 9 inches, and the height
£rom the sole to- the commencement of the sloping bridge 6
feet 4 inches. It tapers slightly towards the top, so as to nci-
litate the descent <^thefhel, which is introduced through a late-
ral opening near the top of the generator. Its cubical contents
are about 44 feet 1015
The air necessary for the production of thens is supplied by
a feeble blast, and enters the generator fh>m the two openings
or tuyeres of a long air chest of iron plate (/^. 1018, 1014, 101 5)
fixed at the back of the chamber, near the bottom. Tbe space
between the air chest and the sole of the chambers serves as
a receptable for the slag and ash fhim the fheL There are open-
ings on the other side of the chamber, opposite the tuylres,
which are generally closed by iron plugs, but are required
when the tuyeres have to be cleaned out There is an opening
below the air-chest, through which fire is introduced into
the chamber, when the ftimace is set to work, and which is
then bricked up, until at the expiration of about 14 days it be-
comes necessary to let the fire die out, when the slag and
ash which have accumulated on the sole of the chamber are
removed through this opening.
The hearth of the fhmace is constructed of a somewhat loamy sand ; its general
thickness is about 6 inches, its form is that of a shallow dish, with a slight incline
towards the tap hole ; the iron is prevented firom penetrating through the hearth by
the rapid circulation of cold air below the fire-bridge and the plate of the hearth.
Figs. 1016 and 1017, represent the upper oblong air-chest provided with a series of
tuyeres, which enter the top of the furnace just over the fire-bridge at an angle
of 30^. The air forced into the fhmace through tfiese tuydres 1016
serves to infiame and bum the gases rushing out of the gene-
rator, and the direction of the blast throws the resulting fiame
down upon the metal on the hearth, in front of the bridge.
This air-chest communicates, like the other one, by pipes,
with the air accumulator of the neighbouring blast furnace.
The amount of pressure employed is about 4 lbs. ; but the
snpply of air, both to the generator and the infiammable gases,
admits of accurate regulation by means of valves in the con-
necting pipes. There is an opening in the arch at both sides |q]7
of the fnmace, not fiir from the bridge, into which, at a certain
stage of the operations tuyeres are introduced (being placed at
an angle of 25^) also connected with the blast apparatus and
provided with regulating valves.
The refining process is conducted as follows : — The hearth of the fVimace having
been constructed or repaired, a brisk coal- fire is kindled in the generator, through
the opening at the bottom, which is afterwards bricked up. About 20 cubit &et of
eoali kre tlwii fnlrodac«d from abort, and the neeeNair lOfftf tit tat tdmllleiu
the geoeiBtor through the loirer eir-cheit Wb«n th«(« cotJ* hsTC beat thorMihlj
ignited, the generatur u filled vith ooali, sod ■ yery moderate nippl; of lir idniOtd
through the (ujdres b«low (foi the generslion of the gae)) and thoM oier ihe tinl|t,
Eck*! Ou BnettwrUiuy Funu
LcmgHedlntl Si
(for its eombnition.) anli] the famaee la dried, when the npply of air at J^ P"*^
ii iPGTCMed, 10 aa 10 raiie the hearth to the teDiperatiiTe necewarr for b"''*.
thoroaghlj, opoD which, about 40 cwt. of iron an inlrodaced [ the metal «'"£"|
tributed over the nhole hearth a« miiformlj aa poaible, and the aiie of the pM"
being telecled with the view to cipoae u much *ar&e« u pouible to tlie flame.
The fWon of the cbaige <tt metal u effeeted in kboat three honra, the coal owd
•mountiiig to about 3j cubic ftet per hour. The gM Braerator ii alwari kept filled
1010 1011
witb coal, aud the inpply of air admllted fVom beloir ii diminiahed hy a Tcgnlatioo
of the TfliTe, wheoeTer fresh coal i» sai^lied, as the latter, at Hrat, alwaji yieldi ^
more fteely. The amuigeineDt of the upper row of tnjire* eflfect* the combwlion
576 IRON.
of gases just as tbey pau from the generator on to the hearth. The hottest portion of
the furnace is of course near the fire-bridge, t. e. where the blast first meets with die
gases. During the melting process the iron is shifted occasionally, so that the cooler
portion near the flue may in its turn become melted without loss of time. When
the iron is ascertained to be throughly fiised, about 5 lbs. of crusted hmestone ue
thrown orer its surfhce for the purpose of converting the dross which has aepanled
into fhsible slag. The two side tuydres are now introduced into the fbrmwes through
the openings above alluded to, the width of the noszle employed depending npoo the
power of the blast used. The air rushing firom these tuylres impinges wiUi Tiolenee
upon the iron, and the two currents meeting an eddying motion is imparted to the
fused metaL In a short time the motion produced in the mass is connderdde ; the
supernatant slag is blown aside by the blast, and the snrfiuse of the iron thus ezpoied
undergoes refinement, while it changes continually, the temperature of the vhole
mass being raised to a full white heat, by the action of the air. The iron it itirred
occnsionaUy, in order to insure a proper change in the metal exposed to the action of
the blast A shovelftd of limestone is occasionally thrown in (the total qiuntitjr
used being about 1 per cent of the crude-iron employed). The slag produced is ei-
ceedingly fusible, and is allowed to remain in the fhmace nntU the metal ii t^ped,
and on cooling it separates firom it completely.
The duration of the treatment in this furnace after the metal is fused, varies from
two hours and a half to five hours, according to the product to be obtained. For
the preparation of perfectly white iron, the treatment is carried on for five hoon A
sample is tapped to examine its appearance, when it is believed to be sufficieDtlj
treated.
When the charge is to be withdrawn ftrom the fbmace, the side tuyere nesreit the
taphole is withdrawn, so that the blast firom the opposite tuyere may force the metal
towards Uie hole. The fluid iron, as it flows from the taphole is fully white hot, and
perfectly limpid ; it chills, however, very rapidly, and soon solidifies. A few pails
of water are thrown upon those portions of the metal which are not covered with the
slag, which flows out of the furnace, the object being to cool it rapidly, sod thu
prevent the oxidation of any quantity of iron. The loss of metal during the treat-
ment is said not to exceed 5 per cent
With regard to the purification which the iron undergoes in the gas reverhentorf
furnace, it appean to be confined chiefly to the elimination of carbon and siliciom,
the amount of sulphur and phosphorus undergoing but little alteration, as appears from
the following analysis (^Abet) : —
Pig iron. Refined Iron.
Silicium - - - 4*66 - . . o*62
Phosphorus - - 0*56 ... 0'50
Sulphur ... 0*04 - - - 0*03
Nevertheless the iron thus refined is highly esteemed for all castiogs which are
required to possess unusual powen of resistance : some experiments made to aaoertain
the comparative strain borne by the refined metal, and the same metal as obtained from
the blast furnace, showed the strength of the former to be greater by one half than
that of the latter.
The operation of puddling. — In the year 1783 and 1784, Mr. Heory Cortof Gospoit
obtained two patents, one for the puddling, and the other for the rolling of iron, "dis-
coveries," says Mr. Scrivenor, ** of so much importaoce in the manufactore, that it
must be considered the era from which wc may date the present extenaiTe and
flourishing state of the iron trade of this country."
The object of Mr. Cort*s processes was to convert into malleable iron, csst or pig
iron, by means of the flame of pit-coal in a common air furnace, and to form the re-
suit into bar by the use of roUen in the place of hammen. The process was ma-
naged in the following manner : — ** The pigs of cast iron produced by the smelting
furnace are broken into pieces, and are mixed in such proportions according to their
degree of carbonisation, that the result of the whole shall be a grey mm. The
mixture is theu speedily run into a blast furnace, where it remaios a suflleient time to
allow the greater part of the scoriaa to rise to the surface. The furnace is now
tapped, and the metal runs into moulds of sand, by which it is formed into pigs* ^ihoni
half the size of those which are broken mto pieces. A common reverberatory for-
nace heated by coal is now charged with about 2^ cwt of this half re6ned grey iron.
In a little more than half an hour, the metal will be found to be nearly melted ;
at this period the flame is turned o£^ a little water is sprinkled over ir, and a workman,
by introducing an iron bar through a hole in the side of the furnace, begins to stir
the half fluid mass, and divide it mto small pieces. In the course of about 50 minntes
from the commencement of the process, the iron will have been reduced by cooftant
IRON. 577
ctirriD^ to the consisteiice of small grave], and will be coDsiderably cooled. Tbe
flame is then tarned on again, the workmen continuing to stir the metal, and in three
minatea* time the whole mass becomes soft and semifluid, upon which the flame is
then turned off. The hottest part of the iron now begins to heave and swell, and
emit a deep lambent blue flame, which appearance is called fermentatUm ; the heaving
motion and accompanying flame soon spread over the whole, and tbe heat of the
metal seems to be rather increased than diminished for the next quarter of an hour ;
after this period the temperature again falls, the blue flame is less vigorous, and in a
4ittle more than a quarter of an hour the metal is cooled to a dull red, and the jets of
flame are rare and fkint During the whole of the fermentation the stirring is con-
tinued, bj which the iron is at length brought to the consistency of sand ; it also
approaches nearer to the malleable state, and in consequence adheres less than at
first to the tool with which it is stirred. During the next half hour the flame is turned
off and on several times, a stronger fermentation takes place, the lambent flame also
becomes of a clearer and lighter blue ; the metal begins to clot, and becomes much
less fusible and more tenacious than at first The fermentation then by degrees sub-
sides ; the emission of blue flame nearly ceases ; the iron is gathered into lumps and
beaten with a heavy-headed tool. Finally, the tools are withdrawn, the apertures
through which they were worked are closed, and the flame is again turned on in full
force for six or eight minutes. The pieces being thus brought to a high welding
heat are withdrawn and shingled ; after this Uiey are again heated and passed
through grooved rollers, by which the scorise are separated, and the bars thus forcibly
compressed acquire a high degree of tenacity." But this mode of refining did not
produce altogether the desired result It was irregular ; sometimes the loss of iron
was small, but at others it was very considerable, and there were great variations in
the quality of the iron, as well as in the quantity of fuel consumed. These difficulties
were, however, removed by the introduction of the coke finery by the late Mr. Samuel
Homfray, of Penydarran, upon which the puddling and balling furnaces came imme-
diately into general use, with the addition of rollers in lieu of hammers.
Mr. Cort's first patent, which is for "rolling,** is dated 17th January, 1783; his
second, that for ** puddling,'* is dated 13th February, 1784. It has been attempted,
thou^ we think very unjustly, to detract from Cort's merits as an original inventor,
by referring to the patents of John Payne, and Peter Onions, dated respectively 2Ut
November, 1728, and 7th May, 1783. The first was to a certain extent, undoubtedly,
a patent for " rolling ; " for the bars rendered malleable by a process indicated, are
" to paM9 between the large metaU rowlers which have proper notches or furrows upon
their surface:** but there is no proof that any practical use was made of Payne's pro-
cess, while that of Cort was almost immediately and universally adopted : it may be
true therefore that Cort was the rediscooerer and not the actual discoverer of the
process of rolling, but this in no way detracts from his merit, inasmuch as by his im-
provements, he was enabled to make available that which was previously useless.
The same observation applies to the patent of Onions, which to a certain extent anti-
cipated that of Cort for puddling. Onions employed two ftirnaces — a common smelt-
ing furnace, and a furnace of stone and brick, bound with iron work and well annealed,
into which tbe fluid metal was received from the smelting furnace. When the liquid
metal had been introduced into the second furnace by an aperture, it was closed up
and subjected to the heat of fuel and blast from below, until the metal became
less fluid, and thickened into a kind of paste ; this the workman by opening a door
turns and stirs with a bar of iron, and tben closes the aperture again, after which
blast and fire is applied until there is k ferment in the metal ; the adherent particles of
iron are collected into a mass, reheated to a white heat, and forged into malleable iron.
That the procees of puddling is here indicated there can be no doubt, but the actual
operation was impracticable until Henry Cort iuTented the furnace in which it could
be conducted.
Neither Mr. Cort nor his family appear to have derived much advantage from his
important discoveries — discoveries which changed us at once from dependent importers
of iron into vast exporters to every country of the world, and which may be considered
to have founded the iron industry of Great Britain. So long ago as 1811, the chief
representatives of the trade assembled at Gloucester unanimously acknowledged their
indebtedness to Mr. Cort for the improvements of which he was the author, and this
acknowledgment has been repeated within the last twelvemonths by Robert Stephenson,
Fairbaim, Maudslay and Field, Cubitt, Hendel, Sir Charles Fox, Bidder, Crawshay,
Sailey, and many others. In working out his inventions, Cort is said to have expended
a fortune of 20,000^, and when his patents were completed, the leading iron masters
of the country contracted to pay him 10«. a ton for their use, so diat he would not
only have been repaid, but munificently rewarded, had he not unfortunately connected
himself with a man named Adam SelUcoe, chief clerk of the Navy Pay Office, who
Vol. II. P P
S7S moN.
proring to be adeAkoIter, committed taietde, haTing prerloiul^ dotnijed i1k Tttnli
•nd the agTeeinentB with iroDmaMera belooglng to hie partner, Henry CorL I'pn
the dealhof Sellicoe, Ibe premUe^ stock, and entire efiecta of Cort vcre uU bri
•ninmarj procen obtained by the Naij T^j Office, and the nnf ortimate mu whiIb
completely mined.
The puddlntg fmiKt it of the rererberatorj tana. It iabaond genenll J villi Ira.
as repre«ented in the side -vlfw, fig. 10S4, b; means of horiioDUi aai TCrtial kn,
1034
oBundeT. Verj frequently, indeed, the rererberatorf lumuei are limed nib o*
iron platei OTer their -whiile surface. These we retained by oprighl tan of ctf "•
applied to the side walls, and by horiiontal bars of iron, placed urea tlit utb a
roof. The fhniace itself is divided interiorly into three parts ; the >?iv(, >bi
AeorlA, and thejlui. The firepiitce rariec iWnn 3} to 4i feet long, by frem t M I
inches to S feet 4 inches wide. The door-way, by which the coke i< disrpi "
8 inches sijoare, and ia bevelled off towards the oatside of the fUmue. Tlw opeiiil
consists entirely of oast iron, and has a quantity of coal gathered roiud it. Tbekn
of thefire grMe are moTable, to admit of more readily clearing ihem from ulia.
^(?. 1025 is a lougitndinat sectioQ referring to the eleTatioDiJ^. 10£4, tod >^ lOii
is a ground plan. When the furnace it a single one, • tquare hole is left u j"^
of (he fireplace opposite to the door, through which the rakes are iniioto™'
order to be heated.
a is the fire-door; i. the grate i c, the fire-bridge; cf (f, east iion b»it*-|>'^
resting upon cast iron heann e e, which are bolted upon both sides to tbt '"^.JZ.
binding plates of the furnace, /is the hearth covered with cindenor sand ;^''"
main working door, which may be opened and Ghut by means of a Icrer j', "t'JSi
to move it up and down. In this large door there is a hole S inches 'fl'*'*;'^'^
which the iron may be worked with the paddles or rakes ; it may alio be ™~.^
tighL There ia a second working door h, near the flue, for introdaciig the <** "^
IRON. 579
so that it may softcD dowly, ttU it be ready for drawing towards the bridge, t, is the
chimney, fh>ni 80 to 50 feet high, which receives commonly the flues of two furnaces,
each provided with a damper plate or renter, Fiy, 10S7
1027, shows the main damper for the top of the com-
mon ehimney, which may be opened or shot to any
degree by means of the lever and chain. A, fig. 1 025,
is the tap or floss hole for running off the slag or
cinder.
The sole is sometimes made of bricks, sometimes
of cast iron. In the first case it is composed of fire-
bricks set on edge, forming a species of fiat vault It
rests immediately on a bod^ of brickwork either solid
or arched below. When it is made of cast iron, which
is now beginning to be the general practice, it may
be made either of one piece or of several It is commonly in a single piece, which,
however, causes the inconvenience of reconstructing the ramaee entirely when the
sole is to be changed. In this case it is a little hollow, as is shown in the preceding
▼ertieal section ; but if it consists of several pieces, it is usually made flat
The hearths of cast iron rest upon cast iron pillars, to the number of four or five ;
which are supported on pedestals of cast iron placed on laige blocks of stone. Such an
arrangement is shown in the figure, where also the square hole a, fig. 1025, for heating
the rake irons, may be observed. The length of the hearth is usually 6 feet ; and its
breadth varies from one part to another. Its greatest breadth, which is opposite the
door, is 4 feet In the furnace, whose horisontal plan is given above, and which pro-
daces good results, the sole exhibits in this part a species of ear, which enters into
the mouth of the door. At its origin towards the fireplace, it is S feet 10 inches
wide -, from the fire it is separated, moreover, by a low wall of bricks (the fire bridge)
10 inches thick, and from 3 inches to 5 high. At the other extremity its breadth is
2 fleet The curvature presented by the sides of the sole or hearth is not symmetrical;
for sometimes it makes an advancement, as is observable in the plan. At the ex-
tremity of the sole furthest from the fire, there is a low rising in the bricks of 2^
inches, called the altar, for preventing the metal from running out at the floss hale
when it begios to flise. Beyond this shelf the sole terminates in an inclined plane,
which leads to the^os«, or outlet of the slag from the furnace. This^ost is a little
below the level of the sole, and hollowed out of the basement of the chimney. The
slag is prevented flrom concreting here, by the flame being n^ade to pass over it, in its
way to the sunk entry of the chimney ; and there is also a plate of cast iron near
this opening, on which a moderate fire is kept up to preserve the fluidity of the scorise,
and to bum the gases that escape from the furnace, as also to quicken the draught,
and to keep the remote end of the furnace warm. On the top of this iron plate, and
at the bottom of the inclined plane, the cinder accumulates in a small carity, whence
it afterwards flows away ; whenever it tends to congeal, the workman must clear it
oat with his rake.
The door is a cast iron frame filled up inside with fire-bricks ; through a small hole
in its bottom the workmen can observe the state of the furnace. This hole is at other
times shut with a stopper. The chimney has an area of from 14 to 16 inches.
The hearth stands 8 feet above the ground. Its atched roof, only one brick thick,
is raised 2 feet above the fire bridge, and above the level of the sole, taken at the
middle of the furnace. At its extreme point near the chimney, its elevation is only
8 inches •, and the same height is given to the opening of the chimney. The sole is
covered with a layer of finely pounded cinders from previous workings mixed with
mill cinders ; formerly the bottoms were of sand, by which great loss of iron was oc«
casioned, and the metal obtained of inferior quality.
The fine metal obtained by the coke is puddled by a continuous operation, which
calls for much care and skill on the part of the workmen. To charge the puddling'
furnace, pieces of fine metal are successively introduced with a shovel, and laid one
over another on the sides of the hearth, in the form of piles rising to the roof ; the
middle being left open for puddling the metal, as it is successively fused. Indeed, the
whole are kept as for separate as possible, to give free circulation to the air round the
piles. The working door of the furnace is now closed, fuel is laid on the grate, and
the mouth of the fireplace, as well as the side opening of the grate, are both filled up
with coal, at the same time that the damper is entirely opened.
The fine metal in about twenty minutes comes to a white-red heat, and its thin
edged fragments begin to melt and fall in drops on the sole of the furnace^ At this
period the workman opens the small hole of the furnace door, detaches with a rake
the pieces of fine metal that begin to melt, tries to expose new surfaces to the action
of the heat, and in order to prevent the metal from running together as it softens, he
pp2
580 IRON.
removes it from the yicinity of the fire bridge. When the whole of the fine metal bai
thus got reduced to a past^ condition, he must lower the temperature of the fomaee
to preTCDt it from becommg more fluid. He then works about with his paddle the
clotty metal which swells up, exhibiting a kind of fermentation occasioned by the
discbarge of carbonic oxide, burning with a blue flame as if the bath were on fire.
The metal becomes finer by degrees and less fusible, or, in the language of the work-
men, it begins to dry. The disengagement of carbonic oxide diminishes and soon
stops. The workman continues meanwhile to puddle the metal till the whole chai]ge
is reduced to the state of incoherent sand ; the register is then progressively opened.
With the return of heat the particles of metal begin to agglutinate, the charge be-
comes more difficult to raise, or, in the labourer's language, it toorlu keavy. Hie
refining is now finished, and nothing remains but to gather Uie iron into balls. The
puddler with his paddle takes now a little lump of metal as a nucleus, and makes it
roll about on the surface of the furnace, so as to collect more metal, and form a ball
of about 60 or 70 lbs. weight With a kind of rake called in England a doBy, and
which he heats beforehand, the workman sets this ball on that side of the fdnaee
most exposed to the action of the heat in order to unite its different particles, which
he then squeeses together to force out the scoriae. When all the balls are laahioned,
the small opening of the working door is closed with brick to cause the heat to rise,
and to facilitate the welding. Each ball is then lifted out either with the tongs.
if roughing rollers are to be used, as in Wales, or with an iron rod welded to the Inxnp
as a handle, if the hammer is to be employed, as in Staffordshire. It is nsoal to in*
troduce a fresh charge when the portion under operation has arrived at the pasty con-
dition ; when this is done, the entire process is effected in about 1^ hour.
The charge for each operation \b from 4 cwts. to 4} cwts. of refined metal, and
sometimes the cuttings of bar ends are introduced, which are puddled apart The loas
of iron is here very variable, according to the degree of skill in the workman, who by
negligence may suffer a considerable body of iron to scorify or to flow into the
hearth and raise the bottom. Taking the average of 85 furnaces for 22 years* work-
ing Mr. Truran finds the consumption of refined metal to produce one ton of pnddle
bars to be 21 cwt. 1 qr. 20 lbs. The consumption of coal is likewise subject to varia-
tion. With coal of good quality, and suitable for reverberatory furnaces, the ton of
puddled bars is produced with a consumption of from 12 to 15 cwt. ; but, if the eoal
be of the anthracitic character, from 18 cwt to 1 ton will be required. Aboat five
puddling furnaces are required for the service of one smelting furnace and one refi-
nery. Each furnace, with good workmen, turns out about 23 tons of paddled bars
weekly.
The cast iron bottom and sides of the puddling furnace are kept cool hj enrrents of
air, or, in those portions exposed to the greatest heat, by water. The cmdere of the
charcoal finery are much esteemed for lining the bottom. When melted into one
uniform mass, with the addition of oxide of iron, these scoriie form a bottom <^ering
great resistance to the action of the melted metal.
Various patents have been taken out within the last four or five years for the em-
ployment of chemical agents to assist in the purification of iron in the paddling
furnace : some of these have already been alluded to. One of the latest is that of
M. Charles Pauvert of Chatellerault, who proposes to employ a cement composed of
the following substances : — oxide of iron, 14 parts; highly aluminous clay, 30 parti;
carbonate of potash, 1 part ; carbonate of soda, 1 ]>art The iron is to be placed with
the cement in layers, and heated in the furnace in the ordinary manner. After ce-
mentation it is welded, and then drawn into bars ; it is stated to become that as sofi
and tenacious as iron made from charcoal. Schaf bruit's compound, for which a
patent was secured in 1835, is said by Overmann to furnish very satisfiiictory resnhs,
and where competent workmen are employed, a good furnace is said to make a heat in
two hours, producing neither too much nor too little cinder in the furnace. The com-
pound consists of common salt 5 parts ; oxide of manganese, 3 parts ; fine white plastic
clay, 2 parts. The pig is heated as in common operations. It is melted down by a
rapid heat the damper is closed, and the cinder and metal diligently stirred. In the
meantime the above mixture, in small parcels of about half a pound, is introduced in
the proportion of one per cent of the iron employed ; if, after this, the cinder does
not rise, a hammer slag (rolling mill cinder) may be applied.
The ** BoUinff'* process. — In this operation, which was the invention of Mr. Joseph
Hall, pig iron is converted into malleable iron without ihe intervention of the refinery,
and without any excessive waste : it is, therefore, of great value, especially as it
allows of ^e use of better qualities of pig iron than those usually employed. The
construction of the ** boiling " furnace does not materially differ ftom that of the
** puddling " furnace, except in the depth of the hearth, that is, in the distance from
the work plate below the door to the bottom plate, which, in the fonner, is doable, or
IRON. 581
nearly 9O9 that of the latter. In the pnddlia^ fomace the distance between the bottom
and top seldom exceeds twenty inches, while in the boiling fnmace it yaries from
twenty to thirty. In puddling the furnace is charged with metal alone, but in boiling
cmder is charged along with the metal, and the temperature rises much higher. The
bottom of the furnace is covered with broken cinders from previous workings, or
with the tap cinder from the puddling Aimace, which has been subjected to a process
of calcination in kilns ; this material, which constitutes an admirable protection to the
iron plates of the furnace, is called by the workmen "bull dog ; " its preparation was
patented by Mr. Hall in 1839. It is made in the following manner : the tap cinder
from the puddling furnace is placed in layers in a kiln, and so arranged that a
draught shall pass through from the fire holes on one side to those on the other ; the
kiln is filled up to the top with broken cinders, and over the whole is laid a layer of
coke ; about the third or fourth day, the more fusible part of the cinder begins to run
out of the bottom holes, leaving in the kiln a fine rich porous silicate of iron, which is
the substance used for lining the boiling furnace, the fluid portion being rejected.
In 8 or 10 hours the ** bull dog '* is melted by the intense heat of the frimace, covering
the bottom, and filling up all the interstices in the brickwork ; the heat is now some-
what lowered by diminishing the draught, and the charge of pig (from 3^ to 4^ cwts.)
introduced in finigments of a convenient and uniform size, together with 30 or 40 lbs.
of cinder ; the doors of the furnace are now closed, and all access of cold atmospherio
air prevented, throwing fine cinder or hammer, slag round the crevices, and stopping
up the work hole with a piece of coaL In about a quarter of an hour the iron begins
to get red-hot ; the workman then shifts the pieces so as to bring the whole to a state
of uniformity as regards heat. In about half an hour the iron begins to melt ; it is
constantly turned over, and at intervals of a few minutes cinder is thrown in; the sur-
fiMe of the mass is seen to be covered with a blue flame; it soon begins to rise ; a kind
of fermentation takes place beneath the surface, and the mass, at first but a inches
high, rises to a height of 10 or 12 inches, and enters into violent ebullition. During
the time that this ** fermentation " is taking place, constant stirring is required to pre-
vent the iron from settling on the bottom. The boiling lasts about a quarter of an
hour ; after which the cinder gradually sinks, and the iron appears in the form of
porous spongy masses of irregular size, which are constantly stirred to prevent their
adhering together in large lumps, to facilitate the escape of the carbon, and to sepa-
rate the cinder which, when the operation has been successfully conducted, flows over
the bottom apparently as liquid as water. The iron is now ** balled up," as in the
operation of puddling. The objections to the boiling process are: the wear and tear
in the fbmaoe which occurs in treating grey pig iron, particularly that of the more
fluid description ; the slowness of the operation, and the amount of manual labour
which it entails to produce good results. In some works the crude iron is run di-
rectly into the boibng furnace from the blast furnace, by which much saving of coal
is effected, and a product of a more uniform quality obtained ; but the labour of the
workman becomes more oppressive from the additional heat to which he is subjected
from the close proximity of the blast furnace. Ironmasters are not a^eed as to the
respective merits of the '* boiling" and ** puddling" systems; some mamtain that the
former is more economical than the latter, which involves *' refining; ** others think
that boiling iron has a tendency to communicate to it the ** red short " quality. Ac-
cording to the observations of Mr. Truran, in several works where both methods are
employed, the largest quantity of hx)n is first passed through the refinery.
Mr. Hall, the inventor of the boiling system, in descanting on the merits of his pro*
cess, describes how, with the same pig, the iron may be made weak and cold short ;
or tough, ductile, and malleable. For the first proceed thus : — Pass the pig through
the refinery, then puddle agreeably to the old plan on the sand bottom ; that is, melt
it as cold as possible ; drop the damper quite close before the iron is all melted, dry the
iron as expeditiously as may be, with a large quantity of water; and, lastly, proceed
to ball in a proper number of ** young " balls ; the result will be a very inferior quality
of manufactured iron. On the other hand, to produce a malleable iron of very superior
quality, first charge the furnace with good forge pig iron, adding, if required, a
snfl&ciency of 'flux, increasing or diminishing the same in proportion to the quality
and nature of the pig iron used. Secondly, melt the iron to a .boiling consistency.
Thirdly, clear the iron thoroughly before dropping down the damper. Fourthly,
keep a plentiful supply of fire upon the grate. Fifthly, regulate the draft of the
furnace by the damper. Sixthly, work the iron into one mass, before it is divided
into balls ; when thus in balls, take the whole to the hammer as quickly as possible,
after which roll the same into bars. The bars being cut into lengths, and piled to
the desired weights, are then heated in the mill furnace, welded and compressed by
passing through the rolls, and thus finished for the market In this way, from the pig
to the finished mill bar, one entire process, that of the refinery, is saved. Mr. Hall
p p 3
582
IRON,
■Utca that, bj liii pKHMM, be can obtain nuUeable iron of uy ebmeter (iwi»li'i»g
tbat Ihe ottn from which the pig i» imeited ue of good qtuditj), &^>in tbe ■oftoMi id
lead to the bftrdneu of it«el, ud ftutber that be can ezbibil different qualities in Ibc
■ame bar, one end being crjatalline, nearlj at briule ii glam, tiie other end eqoal to
the best iron that con be produced for fibre and tenacic;, while the middle ciJubili a
ohaneter approximatiog to both i and u a iiirther illiutratioa of tbe exccUeBce of the
iron that maj be made bj the " pig boiling " process, he refers to a ipecim^ in the
Geological Mnseaiii, Jenuyn Street, London, labelled ' Specimen of ivo and a
quarter inch round iron, tied cold, maao&ctared at the Bloomfield Iron Wcik^
Tipton, Staffordshire." This specimen hat been called a " Staffordshire kitot,* it wis
made from a bar two inchea and a quarter in diameter, and near); seTtni inches i>
circumfercDce ; also to a " Ponched Bar," half inch thick, made at one proceu for the
smithy, com menciog with a half inch punch, and tennincting with One siiand a ball^
without exhibiting the slightest fracture.
Mr. Hall was led to the discovery of the "boiling" principle, by noticing the
eiceedinglj high fusion which took place on gnbjecting paddling famace slag to a
high degree of heat, and tbe eicelleoce of tbe bloom of iron produced by the <^)«ra-
tion : it occurred to him, that if Buch good iron could be made from cinder alone, a
Tery superior product ought to be obtained tnaa good pig iron, with equally good
fluxes, and the result of eipenments fully answered his eipectat ion, though for a long
time he was unable to make his discovery practically useful, on account of the difi-
culty or getting furnaces constructed capable of rendering the intense heat rrquind
and Ihe corroding action of the fluxes. Puddling furuaces were then made of brick
and clay, with sand bottoms. He succeeded at last by lining the interior of the fnmacc
with iron, and protecting them with a coating of prepaired tap cinders.
In America, the " puddling " and " boiling " processes are both in use. Ovoman
gives preference to the latter as bein^ the most profitable, but it cut only be «>-
ployed to a limited extent for lack of cinder i in a rolling mill forge, tbenfoic, half
1038
paddling ftunaces are oa-
tdoyed and a blast is med. the
Incombustibility of this variety
of coal rendering it inipoa-
sible to get the reqnitiw Mat
by merely tbe draught of the
chimney, ft;. 1 038 upmsut*
an authraeiie (amaee Uaeeted
vertically throngh the grate,
hearth, audchimney. ItdiKn
--- the -'■ -
furnace chiefly in the gnaier
depth of the grate, which is
Dade to contain from twenty
a twenty-four inches ti eokl.
and in the lesser height of the chimiKy, wbicb, as ■ blast is employed, need only
be sufficiently high to carry the hot gasei out of the furnace ; the letters «, a, ■, a,
1. indicate the position of ine iron cross binders, whiob serve to bind logetliCT the
TT box, tbe fl^r« chowi n horiionltl sectioD tbroagh the Rxi^
The viup ara thn* connected, uid fonn ft cloced wheel, in vhicb the kir ig whirled
roond, aitd thrown out at the periphery. The inner use, which reTolrei with th«
vmgi, it fitted u cloaelj u pouible to the cater cue, st Ihe centre near a, a, a, a.
Ilie ipnd of the wingt b •ometime* u much u 1800 rcTolutions per minute. The
ntMianof the axis it prodooed by meaniof a leather or india-rabber belt nod ■ pnlley.
This variety of bn i> used at the puddling fUmaoe* K Ebbw Tale, where the hel ii
■malt cobL
Fi^. 1030 ii a boriiontal tection of the double anthracite puddLng fnmace. The
gnie meanire* 3 feet by 5. The width of (he furnace externally ii from Sj to 6 feet.
The booth ia naoally 6 feet in length It haa two work doon, one directly oppoute
the other. Two tela of workmen are required therefore at the same time ; double
the quantity of metal is cIiaTged, and the yield ii twice that of a single fnmaee ; the
economy it in the room, fuel, and laboor ; one good puddler only being required to
iDtn^e tbeoperatioiL Double poddlinv fumacee are alio used in several works in En^
land, bat ■« Mr. Trnrwi obserrea, the eoonomical advantages attending them m
point of ftiel are lost if Ihe pnddter* do not work well to time : Ibej must bring their
beat* lo the reapectiTe lU^ simaltaneously, fbr if one is kept waiting for a ihort
period by the other, the loss in iron more than balances the reduced consumption
of coaL This difficulty of obtaining men who will work, well in concert haa
operated against the ose of the doable farnaoe, which would olherwise certainly
•Dpetsede &e single, as combined with Ihe process of mnning the iron in liquid from
tbe blast furnace, the consumption of fuel is nnder the one half of the quantity de-
manded with single fomiiceB working cold iroiL
itaddling fumues ore sometimes constructed with what ia railed " water boshes."
Ae hearth is tprronnded with heavy cast iron plates, in which is formed a passage of
an inch or an inch and a half bore, through which a current of cold water is caused
to flow, the object being to protect the famaw from the destmctiTe action of the beat
and cinder. Overman found snch furnaces to work well with fosiUe metal such u i«
produced from a hesvj burden on the blast furnace, or from ores oontaining phoa-
phorns ; bat with tron requiring a strong beat, such as results from a light burden on
the bhut fumace, or when it conlaini impurities Grmly and intimately combined, pud-
dling fdmaees with cooled boshes failed to make good malleable iron.
We do Dot know whether the iron manufacturers in England will assent to the fol-
lowing prDpo«ition laid down by the American metallnrgiit, rii. " That the smaller
the amount of ooal consoiaed. or the lower the temperature of the hearth in the blast
fbmaice. the better will be the quality of Ihe metal ; that is, the more fit it will be-
oome for improvement in the puddling furnace. The adtantage of heavy burden in
the blast fnniace, is not only Uist it rnluces ike first cost of the metal, bat makes a
&i superior article for, subsequent opwrations. The worst cold short, or tulphurooa
metal, smelted by a low heat is quite as good aa the beat metal from the best ore
smelted by a high tempentnre." Whatever may be thought of the latter part of
thia qaotation, no iron manufacturer will deny tluu carefhl attention to the blast
Airnace is (he beat security of saccess in the paddling fumace, and that succcM
in the one is in proportion to the economy observed in relation to the other ; OT that
it is hopeless to attempt to improve in tbe puddling fumace pig iron made in a ftir-
oace thai is constiuilly changing its burden and management t such iron is most ad-
Taalageously disposed of by being worked up into coarse bar oi railroad iron.
In the autumn of 1856 the attention of ironmaatcci and of the publie generally was
powerfiiUy exCited by a proposal from Hr. Bessemer to manufacture iron and steel
584 IRON.
from crude iron, irithoat any fuel at alL The views of Mr. Bessemer were fint com-
municated to the public in a paper read by that gentlemen at the meeting of tbe
British Association held at Cheltenham in August -, from this paper the foUovio; ex-
tracts are taken, descriptive of the aj^aratus employed, and of the phenomeni attend*
ing the conversion.
** The furnace is a cylindrical vessel of three feet in height, somewhat like as ordi-
nary cupola furnace, the interior of which is lined with fire bricks ; and at aboat two
inches from the bottom are inserted fire tuyere pipes, the nozzles of which are fonnedof
well burnt fire clay, the orifice of each tuyere pipe being about three eights of an ioch
in diameter. These are so put into the brick lining (from the outer side), as toadnh
of their removal or renewal in a few minutes when they are worn out At ose side
of the vessel, about half way up from the bottom, there is a hole made for moaiDg in
the crude metal; and on the opposite side a tap hole stopped with loam, by meuu of
which the iron is run out at the end of the process. The vessel is placed so near tbe
discharge hole of the blast furnace as to allow the iron to flow along a gutter ioto it.
A small brass cylinder is required, capable of compressing air to about 8 lbs. or 10 lbs.
to tlie square inch. A communication having been made between it and the tnyte
the converting vessel is in a condition to commence work. Previous, however, to
using the cupola for the first time, it must be well dried by lighting a fire in the io-
terior. The tuyeres are situated nearly close to the bottom of the vessel, the flaid
metal rises, therefore, some 18 inches or two feet above them. It is necessary, in
order to prevent the metal from entering the tuyere holes, to turn on the blast before
allowing the crude iron to run into the vessel from the blast furnace. This hariog
been done, and the fluid iron run in, a rapid boiling up of the metal is heard going on
within the vessel, the metal being to^ed violently about, and dashed fit)m side to side,
shaking the vessel by the force with which it moves from the throat of the con-
verting vesseL Flame will then immediately issue, accompanied by a few bright
sparks. This state of things will continue for about 15 or 20 minutes, daring which
time the oxygen of the atmospheric air combines with the carbon contained in the
iron, producing carbonic acid gas, and at the same time evolving a poverfal heat
Now as this heat is generated in the interior of, and is diffused in innumerable fiery
bubbles through, the whole fluid mass, the metal absorbs the greater part of it, and
its temperature becomes immensely increased, and by the expiration of 15 or iO
minutes, the mechanically mixed carbon or graphite has been entirely coDSimied.
The temperature is, however, so high that Uie chemically combined carboo, nov
begins to separate from the metal, as is at once indicated by an immense increase m
the volume of the flame rushing out at the throat of the vessel. The metal now risa
several inches above its natural level, and a light frosty slag makes its appearance,
and is thrown oat in large foam-like masses. This violent eruption of cinder gene^
ally lasts 5 or 6 minutes, replacing the shower of sparks and cinder which always ac-
companies the boil.
** The rapid union of carbon and oxygen which thus takes place, adds still fiirther to
the temperature of the metal, while the diminished quantity of carbon present, allows
a part of the oxygen to combine with the iron, which undergoes combustimi, and tf
converted into oxide, at the excessive tamperature that the metal has now scqoired;
the oxide, as soon as it is formed, undergoes fusion, and forms a powerful solvent «
those earthy bases that are associated with the iron. The violent ebullition wfaicn
goes on mixes most intimately the scoriss and metal, every part of which is bronght
into contact with the fluid, which will thus wash and cleanse the metal most thorongblj
from the silica and other earthy bases, while the sulphur and other volatile matters
which cling so tenaciously to iron at ordinary temperatures, are drawn o^ the sulphsr
combining with the oxygen and forming sulphurous acid gas. The loss in veigbto
crude iron during its conversion into an ingot of malleable iron was found on ^^^^
of four experiments to be 12 J per cent., to which will have to be added tbe l<w»
metal in the finishing rolls. This will make the entire loss probably not less than
18 per cent., instead of about 28 per cent, which is the loss on the present syBteniL
A large portion of that metal is, however, recoverable, by tr^tingwith earbonaceoos
gases the rich oxides thrown out of the furnace during the boil These slags ««
found to contain innumerable small grains of metallic iron, which are ™*^^*°*?2
held in suspension in the slags, and may be easily recovered by opening the Up «««
of the converting vessel, and allowing the fluid malleable iron to flow into the iro»
ingot moulds placed there to receive them. * . .
** The masses of iron thus formed will be perfectly free from any admixture of cinder,
oxide, or any other extraneous matters, and will be far more pure and in a ^^^^
state of manufacture than a pile formed of ordinary puddled bars. And t^'?. j j
be seen that by a single process, requiring no manipulation or particular ««''» ^
with only one workman, from 3 to 5 tons of crude iron passes into tRe coooiuon
IRON. 585
KYenl piles of malleable iron in from 30 to 35 minates, with the expenditare of aboat
\ of the blast now used in a finery furnace with an equal charge of iron, and with the
consumption of no other fuel than is contained in the crude iron. . . .
** One of the most important fkcts connected with this new system of manufacturing
malleable iron, is that all the iron so prepared will be of that quality known as char-
coal iron, because the whole of the processes being conducted without the use of
mineral fuel, the iron will be free from those injurious properties which that descrip-
tion of fuel nerer fiiils to impart to iron that is brought mider its influence.
** At that stage of the process immediately following the boil the whole of the crude
iron has passed into the condition of cast steel of ordinary quality. By the continuation
of the process the steel so produced gradually loses its small remaining portion of
carbon, and passes suceessiTely from hard to soft steel, and from soft steel to steely
iron, and eventually to very soft iron ; hence at a certain period of the process any
quality of metal can be obtained."
The phenomena attending this novel process of iron making are yery well described
in the above extract, and if we substitute for the words ** a few bright sparks," the
words *' showers of bright sparks, poured out in enormous quantities, projected thirty
or forty feet into the air, and falling on all sides in a thick shower," a good idea
may be formed of the gorgeous display of pyrotechny which is exhibited. We must
demur, however, to the statement that ** the sulphur and other volatile matters present
in the crude iron are drawn off ; " the fact being that the sulphur and phosphorus
appear to have suffered little if any diminution, notwithstanding the excessive tem-
perature and the powerful oxidising action to which the iron has been subjected.
Thus Mr. Abel found, in a specimen of Mr. Bessemer's product from 0*4 to 0*5 per
cent, of phosphorus, and from 0*05 to 0'06 per cent of sulphur ; the Blamarvon pig,
from which it was stated to have been prepared, containing 0*5 of the former and
0*06 of the latter, and in a sample, broken off from an ingot cast at Baxter House,
Sept 1st, 1856, on which occasion we were present, and witnessed the whole process,
we obtained 0*6 per cent of phosphorus and 0*08 per cent of sulphur ; similar results
have been obtained by other chemists. The carbon and silicon, on the other hand,
are eliminated, the latter wholly so, while the quantity of the former is reduced to
a few hundredths per cent ; we think also that Mr. Bessemer is mistaken in stating
that the iron produced by his method contains *' no admixture of oxide," for the
specimens which we have had an opportunity of examining presented unmistakable
evidence of partial oxidation in the very centre of the ingot, nor do we see how it
could well be otherwise.
It will easily be imagined that a process which, if successful, must have revolu-
tionised the whole iron manufacture, was speedily subjected to a most careful and
sifting investigation ; and, for some months after its announcement, the papers were
filled with communications from all parts of the country, detailing experiments made
on the large scale to test its value ; the results, unfortunately for the ingenious pro-
jector, were unanimously un&vourable. We quote first from the ** Mining Journal "
of Nov. 29, 1856.
** The Dowlais Company appear to have thoroughly and impartially tested Mr.
Bessemer*s process, and the results obtained can only be regarded as a total failure.
.... A Bessemer furnace was erected, and acted excellently as far as the process
was concerned, but failed to produce anything like malleable iron. The iron used
was fh>m clay-ironstone, Whitehaven hematite, and small portions of forge cinders,
in the proportions usually employed in Wales for rails and merchant iron. After
the metal had been subjected to a blast of 8 lbs. pressure it was withdrawn and taken
to the * squeezer,* as is usual with puddled blooms, to take out the dross and unite
the particles of metaL Instead of acting like puddled iron Mr. Bessemer's bloom
under the squeeser was a mere mass of red-hot friable matter, and, ftom its crumbling
and non-cohesion, was with difficulty formed into an ingot : when passed through
the rolls it broke on the drawing side as easily as very * red short ' iron, to the infinite
gratification of the men, who greeted each failure with hearty cheers. By mixing
slag with the metal a slight improvement was effected, but, on being submitted to
a similar manipulation, it was found to be no better than * cold short ' iron."
From the " Cambrian," 10th Jan. 1857 : —
'* On December 31st the Briton Ferry Iron Company received two of Bessemer^s
finest ingots of iron to test its value after passing through the rolls. Notwithstanding
every care that was bestowed on the process, it was fotmd impossible to do anything with
it to the purpose, and the manager informs us that old rekit iron, after passing through
the same process, is worth by at least 32. per ton more than that tried on this
occasion."
At a meeting of the Polytechnic Society at Liverpool, Monday, Sept 16, 1856, the
chairman, Edward Jones Eyre, is reported ("Daily News") to have said that a
586 IRON.
gpecimen of BeflieBier*8 iron had been received and tested by Ifr. Clay in the pretenee
of Mr. Dawson and himself, and, he regretted to say, had been far from satiafiaetoiT ;
the specunen submitted had all the appearance of burned and imperfect coat vtai. He
might say it was roUen hot and rotteH cold. Mr. Dawson corroborated this statement,
and also said that he had been much disappointed in the result ; the portion sahmitted
to the rolling machine had proved in every way intractabie. The chairman added
that he hoped ere long better results would be obtained ; but in the one to whieh he
referred he was informed that the iron cost 6L per ton originally, and alter being
operated on, as he saw it, he did not consider it worth 4L per ton.
Lastly, we find in the '* Mining Journal'* of January 3rd, 1857, that the Pease bmt
process was tried at the works of Messrs. Jackson, near Glasgow. The nsoal ap-
pearances were noticed, and after about 40 minutes the fumaoe was tapped, and tke
purified iron ran white and limpid into moulds prepared for the purpose. After al-
lowing it to cool it was examined; it had a bright silvery whiteness with large
crystals, but was exceedingly brittle. When rolled it preserred the same crystalline
appearance on fracture, but in a state of greater compression and without the slightest
trace of fibre. It is stated to have been deficient in every quality which would render
it valuable for such purposes as malleable iron is usually applied to — in fact, the
specimens examined were not malleable, and had nothing of tenacity or ductility,
properties which render iron valuable, and are so indispensable for the mechanical
requirements of the present age.
Although, therefore, it is scarcely probable that fibrous iron will ever be made from
metal that has been subjected to Bessemer*s treatment, and although that gentieman
was premature in announcing his invention as a thing proved to be practical, we are
far from asserting, as some have done, that the time of iron masters has been need-
lessly occupied in experimenting on the subject, or that no good is likely to accrue to
the iron manufacture from all that has been done and written thereon. The extra-
ordinary tenacity with which iron retains sulphur and phosphorus has been exhibited,
and the fiict that we must resort to other oxidising agents than that of air to eliminate
them has been demonstrated. The injurious effect of an excessive temperature on
the body and quality of iron has been clearly manifested, and the opinions of those
whose experience has taught them that it is vain to look for the prodactioi of a
tough flexible bar from iron which has lost nearly the whole of its carbon, rapidly or
without manipulation, has been confirmed. It is more than probable that iron eon-
taining only 0*05 per oent of carbon has almost lost the property of becoming
fibrous by any treatment ; for without going so far as to assert that the development
of fibre depends on the presence of carbon, or that carbon exercises a specific fone-
tion in bringing about this molecular condition of the iron, analysis shows that the
toughest and most flexible bar iron contains a far larger quantity of carbon than that
above indicated, as will be seen by the following analyses by Gay-Lnasac, WiUson»
Karsten, and Bromeis.
Amovnt of Carbon ta Bar Iron,
Best bar iron from Sweden ...-•... o^s
f* 0-S40
Bar iron from Greusat -----.--- o-i59
Bar iron from Champagne ... ..... 0*198
Bar iron flrom Berry ----.--.-- 0-162
Cold short bar iron from Moselle ....... 0-144
Soft bar iron analysed by Karsten ....... 0-200
Hard bar iron by Karsten ........ 0-500
Three different varieties produced firom white pig iron by the Swabtan
method of refining, analysed by Bromeis ...... 0-318
Three different varieties produced from white pig iron by the Swabian
method of refining, anidysed by Bromeis ...... 0-354
Three different varieties produced from white pig iron by the Swabian
method of refining, analysed by Bromeis ...... 0*40
Three varieties produced from various kinds of pig iron by the Magde-
sprung method of refining ........ 0*324
Three varieties produced from varions kinds of pig iron by the Magde-
spmng method of refining ........ 0-497
Three varieties preduced from various kinds of pig iron by the Miigde-
sprung method of refining ........ o*66
It will be noticed that the smallest amount of carbon indicated in these analyses is
neariy three times greater than that found in Bessemerised iron, and in this specimen
the iron is stated to be ^* cold short " which means deficient in fibre ; it is probable that
IRON.
587
iron reUint the lait portion of earbon with extraordinary tenaeitj, and that it can only he
made to yield it np by the aetion of exoesuTe teinperatare and oxygen ; it then panes
into a condition of what is called burnt iron which Gmelin states, (yoLjt. p. 205,
English TroMdationy, is the only raricty of bar iron that is free from carbon. This is
elearly the condition of the ingots made by Bessemer's process ; it is stated, however, that
by proper management any desired quantity of carbon may be retained, and it remains
to be proved how &r this will be practicable on the large scale, and whether those
Tarieties of steel and semi-steel alluded to in the patents can really be prodnced.
Some interesting experiments on fused wrought iron hare recently been made by
Mr. Riley of the Dowlais Iron Works. By exposing fragments of block plate from
the tin works for two hours to the highest heat of a wind furnace, the fragments being
covered with cinder from an old assay, a perfectly fused button weighing 1 638 grains was
obtained. When cold the mass was crystallised and easily broken, the fracture being
in the direction of the planes of cleavage of the crystals ; one half of the button being
worked out into a ^ inch bar was very soft, with a fine fkce, and sharp even edges like
steel ; two peices when welded together worked well at a welding heat, but on cooling
to a red heat became cracky and broke. The fracture of the iron before it had been
exposed to welding heat was silky and the body was very tongfa ; it could readily be bent
back double without cracking. This experiment was repeated several times, with similar
results, the fosed buttons being very tough and fibrous when cold, but invariably
cracking and breaking to pieces after having been subjected to a welding heat. It
would appear, therefore, that fused wrought iron is almost a worthless substance.
Mr. Riley is engaged in further experiments, which, it is to be hoped, will throw some
light on this singular property of fused wrought iron.
Machines for forging and condensing iron, — To prepare the pnddle balls for the
rolling mills, they have to undergo the process *' shingling ; '* or ** blooming ; *' this is
effect^ either by the hammer or by the squeezer: the latter has almost entirely
superseded the former, as it effects the object at less cost, though, perhaps, with hardly
such good results as to quality. These mechanisms are moved either by steam
engines or by water-wheels. We shall offer some details concerning them.
The main driving shaft usually carries at either end a large toothed wheel, which
commnnicates motion to the different machines through smaller toothed wheels. Of
Uiese there are commonly six, four of which drive four different systems of cylinders,
and the two others work the hammer and the sheara. The different cylinders of an
iron work should never be placed on the same arbor, because they are not to move to-
gether, and they must have different velocities according to the diameter. In order to
economise time and facilitate labour, care is taken to associate on one side of the
motive machine the hammer, the shears, and the reducing cylinders, and on the
other side, to place the several systems of cylindera for drawing out the iron into
bars. For the same reason the puddling furnaces ought to be grouped on the side of
the hammer; and the reheating furnaces on the other side of the works.
The hammers, fig. 1031, are made entirely of cast iron ; they are nearly 10 feet long,
and consist usually of two parts, the helve c, and the head or pane <L The latter
588
IRON.
enters with fHction into the fonner, and it retained in its place by wedges of iixm or
wood. The head consists of several faces or planes receding fit>m each other, for
the pnrpMe of giving different forms to the ball lumps. A ring of cast iron a, called
the cam-ring iMg, bearing movable cams b 6, drives the hammer d, by lifting it np
round its fulcmmyi and then letting it fall alternately. In one iron work, this ring
was found to be 3 feet in diameter, 18 inches thick, and to weigh 4 tons. The weight
of the heWe (handle) of the corresponding hammer was 3 tons and a half, and that of
the head of the hammer 8 hundred weight
The anvil e consists also of two parts ; the one called the pane of the anvil, is the eoon-
terpart of the pane of the hammer ; it likewise weighs 8 hundred weight The second p;
named the stock of the anvil, weighs 4 tons. Its form is a parallelopiped, with the
edges rounded. The bloom or rough ball, from the puddle ftiinace, is hud and tamed
about upon it, by means of a rod of iron welded to each of them, called a porter. Since
the weight of these pieces is very great, and the shocks very considerable, the utmost
precautions should be taken in setting the hammer and its anvil upon a substantial
mass of masonry, as shown in the figure, over which is laid a double* or even quadruple
flooring of wood, formed of beams placed in transverse layers close to each other. Soch
beams possess an elastic force, and thereby partially destroy the injurious reaction of the
shock. In some works, a six-feet cube of cast iron is placed as a pedestal to the anviL
Forge hammers are very A%quently mounted as levers of the first kind, with the
centre of motion about one-third or one-fourth of the length of the helve from the cam
wheel. The principle of this construction will be understood by inspection of Jig. 1039:
The short end of the lever which is struck down by the tappet c, is driven against the
end of an elastic beam a, and immediately rebounds, causing the long end to strike a
harder blow upon the anvil s.
Fig, 1032 is the German forge-hammer ; to the left of 1, is the axis of the rotatory
cam, 2, 3, consisting of 8 sides,
each formed of a strong broad bar
of cast iron, which are joined to-
gether to make the octagon wheel.
^ 4, 5, 6, are cast-iron binding rings
\ or hoops made fast by woodeo
1 wedges; 6,6, are standards of the
I frame work e, /, m, in which the
helve of the forge hammer has its
fulcrum near v. A, the sole part
of the firame. Another cast-iron
base or sole is seen at m. a is a
strong stay, to strengthen the
frame- work. At r two parallel
hammers are placed, wiUi cast*
iron heads and wooden helves, s is the anvil, a very massive piece of cast iron. ( is
the end of a vibrating beam, for throwing back the hammer from it forcibly by recoil
jr y is the outline of the water-wheel which drives the whole. The cams or tappets aie
shown mounted upon the wheel 6, jjr, 6.
Squeezers are machines which condense a ball by pressure. They are either single
or double, their construction will be readily understood from Jig. 1033, which represents
a single level squeezer of the simplest construction ; the bed plate a is cast in one
piece; it is 6 feet long, 15 inches wide, and 12 inches high. The whole is screwed
down on a solid foundation of stone, brick, or timber : b is the movable part, which
IRON.
589
makes from 80 to 90 motioDB per minute. The motion is imparted by the crank e,
-which in tnm is driven by means of a strap and pnlley by the elementary power. The
diameter of the fly wheel is from 3 to 4 feet The anvil d is about two feet in length
and from 12 to 14 inches in width; it is a movable plate, at least 3 inches thick,
which if injured can be replaced by another ; the face of the working part of the IcTer
exactly fits the anvil, and consists of plates attached by means of screws. It is
desirable to have all these &ce plates in small parts of 8 or 10 inches in width, by this
means they are secured against breaking by expansion and contraction. The whole
machine, including the crank and everything, is made of cast iron, and weighs from 4
to 5 tons. According to Overman this machine is both cheap and durable, and will
sqaeese 100 tons of iron per week.
Fig. 1034 represents the double sq|ueezer, employed at many English iron works.
The drawing is taken from a machine at the Dowlais iron work^ figured in Mr.
Tmran's work. Many other forms are in use.
Fig, 1035 represents Brown's patent bloom squeezer. The heated ball of puddled
iron K, thrown on the top is gradually pressed between the revolving rollers as it
descends, and at last emerges at the bottom, where it is thrown on to a movable
** Jacob*s ladder,** by which it is derated to the rolls. This machine effects a con-
siderable saving of time, will do the work Of 12 or 14 furnaces, and may be constantly
going as a feeder to one or two pairs of rolls. There are two distinct forms of this
machine ; in the one figured the bloom receives only two compressions ; in another,
which is much more effective it is squeezed four times before it leaves the rolls
and falls upon the JacoVs ladder. Another form of squeezer is shown in^^. 1036.
A table ▲ ▲ with a ledge rising up from it to a height of about 2 feet, so as to
form an open box, is firmly imbedded in masonry ; within this is a revolving box, c,
of similar character, much smaller than the last, and placed eccentrically in regard to
590 moN.
it. The IwU or bloom d i» placed between the innerBiost TGTolTiDg box C knd iKe oater
MM ±. ±. There Ibe Bp&ce between them is greMeat, and it carried roond till it emer;gel
M B, oompresKd and Gl for the rails.
I „_. Cglindert. — The conipreaaioii between crtindoi
now effecta, in a few Mcooda, that eoDdeosauaii and
diMnbation of the fibre*, which 40 yris ago codU
not be accomplished till after muf beats in the fnr-
nace, and maa; blows of the luimrner. The c^lioden
may be dislingniBbed into two kindi : I, ihoae which
Bcrre to draw oat Che ball, caUed pviltimg tvOm, or
1 Toughiag rolls, uid which are, in fact, redacing fjKd-
ders I 3, the cjilioden of eiteniion, called maert, for
' drawing into ban the msuire iron after it h>i re-
ceived a wading, to make it more malleable^ Hbc
second kind of cylinder! ii ■nbdlTided into spienl
rarielleB, accordJDg to the patlemi of hv iroo that
are required. These may vary from £ ioche* sqiiaie
to less than nne-siith of an indi.
Beneath the cylinders there is usually fonned an oblong fosse, into which the sewic
and the scales fall wben the iron is compressed. The sides of tbii fosse, constructed of
■lone, are founded on a body of solid masonry, capable of supporting the enormooi
hiad of (he cylinders. Beams of wood form in some measure the sides of this pit, la
which cylinders may be made fust, by securing them with screws and bolla. Mutiie
bars of oast iron are found, howerer, to answer still better, not only beeaoEe the op-
rights and bearers may be more solidly fixed to them, but because the basement of
heavy metal is more difficult to shatter or displace, an accident which happens fit-
quently to the wooden beams. A rill of water is supplied by a pipe to each [wir of
cylinders, to hinder them from getting hot ; as also to prevent Ihe hot iron froni ad-
beling to the cylinder, by cooling its surfitce, and perhaps producing on it a slight
degree of oxidisement.
The shafts are t foot in diameter for the hammer and tbe roughing rolls; and
6 inches where they comoiunicate motion to tbe cyliaden destined to draw the ino
into bars.
The roKghiiy rofli are employed either to work ont the lump or ball immediately
after it leaves the puddling furnace, as in Ihe Welsh forges, or only to draw oat the
piece, after it has been shaped under the hammer, as is practised in moat of the
Staffordshire eBtahlishments. These roughing cylinders are generally 7 feet long.
including the trunnions, or 5 feel between the bearers, and IB luches diameler ; and
weigh JQ the whole from 4 to 4} tons. They contain frata 5 to 7 grooves, commonly
of an elliptical form, one smaller than another in regular progression, as is seen in fig.
1037. The small aiisof each ellipse, ssfonned by the uniou of the upper and under
grooves, is always placed iu the vertical direction, and is equal to the great axis, or
horizontal axis of the succeeding groove; so that in transferring Che bar Irom one
groove lo another, it must receive a quarter of a revolution, whereby the iron gel*
elongated iu every direction. Sometimes tbe roughing rolls serve as preparatory
cylinders, iu which case they bear towards one extremity rectangular grooves, as the
figure eihibits. Several of these large grooves are best udded with smstl asperities
analc^ous to the teeth of files, for biting the lump of iron, and preventing its sliding.
On a level with the under side of the grooves of ihe lower cylinder, there is a plate of
cast iron with notches in its edge adapted to the grooves. This piece, called the apron,
rests on iron rods, and serves to support Ihe balls and bars exposed to Ihe action of
the rollers, and to receive the fragments of ill-welded metal, which fnll off during the
drawing. The koatiitg framis in which the rollers are supported and revolve, are
made of great strength. Their height is S feet \ their thickness is 1 foot in tbe side
perpendicular to the axis of Ihe cylinders, and 10 inches in the othur. Each pair of
bearer* is connected at their upper ends by tvo iron rods, On which the workmen rest
their tongs or pincers for passing Che lump or bar from one side of thecylinderato the
The cods or bushes are each composed of two pieces ; the one of hard brasa, which
presents a cjrlindrical notch, is framed into the ocher which is made of cast iron, at i*
clearly seen in fig. 1037.
The iron bar delivered from the square grooves, is cut by the shears into short
lengths, which are collected in a bundle in order to be welded together. When this
bundle of bars has become hot enough in the furnace, it is conveyed to the rollen.
which differ in their arrangement nccording as they are meant to draw iron from a
large or small piece. The first, ^. 1037, possess both elliptical and rectangular
grooves; are I foot in diameter and 3 feet long between the bearers. Tbe bar is not
IRON. 591
Sniibed nn^er thew cjlinden, bnt ii trenifbrred to iDother {tair, wboM groorei luTe
the dimeniioDS proper ftn- the Imr, with a ronnd, triasgnlu-, TMtaaguUr, or flllel
Ibmi. The triangular grooTe* made nM of (br (qaare iroQ. hATc for their profile an
iKwcelee triangle iilightlj obtuse, k> that the space left b; the two groovn together loa]'
be a rhombua, dUTering little fTom a aqaare, and wboee smaller diagonal ia lertiGai.
WImh the har ii to be paiaed loceeaiively through WTeral grooTes of thli kind, tha
larger or horilonlal diagonal of each follow ing groove i« made equal to the smaller or
vpnghl of the preceding one, whereby the iron must be turned one fourlh round U
each mcecMTe draugbt, and thus receiye preastire ia opposite dlrmtioiia. Indeed the
W is often titmed in snceession through die triangtilar and rectangular grooTes, that
it* fibres maj be more aoooratriy worked together. The decremeoi in the capacity
of the gnwrea follows the proportion of IS to II.
When it b intended to redtioe the iron to 1037
• small rod, the cylinders have such a dia-
veter, that three may ba set in the same
boaiing ftame. The lower and middle
cjlioden are employed as roughing rollers,
while the upper and middle ones are made
to draw out the rod. When a rod or bar is
to be drawn with a ebsnnel or gutter in its
(hee, the groores of the rollers are suitably
■ employed, ealled iHtUri. Their ridges
are sbsrp-edged, and enter into the opposite
■Tao*es 9j inches deep ; so that the flat har
in poBing between each rollers is initan-
tueoDsly divided iato sereial allps. For
this purpose the rollers represented in^.
1038, may be pat on and remaved from the
ihaA at pleasure.
I03B
TIu
The velocity of the cylinder* varies with
tbcir dimensions. In one work, eylinden
fbr drawing oat Iron of from one-third to
two-thirds of an inch thick, make MO re-
Toluti<Hw per minute; while those for iron
of from two-thirds of an inch to 3 inches,
nake only 85. In another work, the
cylinders for two inch'iron, make 95 revo-
lationi per minute ; those for iron frran two-
thinls of an inch to an inch and a third,
nake 128; and those for bars from one-third
to two-thirds of an inch, 150, The ronjA- '
ing roJJn-i move with only one-third the
velocity of the drawing cylinders.
The shingling and plate-rolling mill is
represented in^y. 1037. The shingling mill,
fbr converting the blooms from the baUing
fiimace into bars, consists of two sets of
grooved cylinders, the first being called
padding rilt or nughtRg roUi ; the second
are for reducing or drawing the iron into
mill-hara, and are called simply rclli.
a, a, a, a, are the powerful uprights or '
standards called hmuiag /rat
: L-_i. ... _ , iof ih,
t bolt rods for bind-
592 IRON.
ing tbae tmaes togelher *t top «nd bottom ; c, are the roaghing roll*, luving euh a
■erin of Iriuignlir grooTO, sacb that between those of the apper uid under cy Uader,
rectanguUr cooc&Tilies are formed in (he circamfereace irith ilightly slopiog tiita.
The end grooTe to the right of c, should be chaanelled like a roaRh file, in order la
take the better hold of the blooms, or to bile the metal as thevorkmeo sa; i andgiTe
il the preparatory elongalioii for entering into and passing througb the renuuniiig
groOTGi till il comes Co the sqaare ones, where it becomes b mill-lnr. d, d, are the
■mooth cylinders, hardened upon the surface, or ckillid, as it is called, by being cast io
iron moulds for rolling iron into plates or hoops, e, e, e, t, are strong screira vlth
rectangularthreads, which work bj means of a wrench or key, into the DDla e* e' «< e*,
fixed in tbe atandBrds ; they serve to regulate the height of the plummer blocks or
bearers of tbe gudgeons, and thereby the distance between tbe upper and under
cylinders. / is a juncliou shaft ; g, g, g, are solid conpling boxes, which embrace the
two separate ends of the shafts, and make them turn together, k, h, are junctina
. pioioni, whereby motion is communicated from the driving shaft/ through tbe
under pinion lo the upper one, and thus to both upper and under rolls at once, t, t,
ore tbe pinion standards in which their shafts ran ; they are smaller than the up-
rights of tbe rolls, t, A, are screws for fastening the head pieces / to the top of the
pinion standards. All the standards are provided with sole plates m, whereby they arc
screwed to the fonndation beams R of wood, or preferably iron, as shown by the
dotted lines ; o, o, are the binding screw bolls. Each pur of rolls at work i> kept
cool by a small stream of water let down upon it from a pipe and stop-cock.
Id the cylinder drawing, the workman who holds the ball in tongs panes it into the
first of the elliptical grooves, and a second workman, on the other side of the
cylinders, receives this lump and hands it over to the first, who repaases it betwe^
the rollers afler bringing them somewhat closer lo each other by giring a turn to the
adjusting pressure screws. After tbe lamp has passed five or six times tfarongb the
same groove it has got an elliptical form, and is called in England a bloom. It ia next
passed Ihrou^ a second groove of less siie, wbicb stretches the iron bar. lo this
state it is subjected to a second pair of cylinders, by which the iron is drawn into
flat bars four inches broad and half an inch thick. Fragments of tbe boll or bloo^
fall round about tbe cylinders, wbicb are afterwards added lo the puddling charge:.
In a minute and a half the rude lump is transformed into ban with a neatneas ud
rapidity which tbe inexperienced eye can hardly follow. A steam engine of thirty
horse power cati rough down in a week SOO tons of coarse iron.
This iron, called mill-bar iron, is however of loo inferior a quality lo be employed
in any machinery, and it is subjected lo another operation, which consists in welding
several pieces together, and working them into a mass of the desired quality. Tbe
. iron bars, while still hot, are cut by the shears into a length proportional to the siie rd
the iron bar that is wanted, and four ruws of these are usually laid over each oiber
into a heap or pile which is placed in the re-healing fumsce, and exposed to a free
circulation of heat, one pile bifiug set crosswise over anoiher. In a half or thrre
quarleri of an hour the iron is hot enough, and the pieces now sticking together are
carried in successive piles to the bar drowing cylinders to be converted into strong
bars, which ere reckoned of middle cfuality. When a very tough iron is wanted, as
for anchors, another welding and rolling must be given. In the re-heating ovens tbe
loss is from 8 lo 10 per cent, on tbe large bar, and from 10 10 IS in smaller work.
The consumption of coals in heating the large piles averages 7 owls, to the ton of iron
charged ; in the smaller siies 10 owls. ; and in healing the guide rolled iron 13 cwls.
The re-heating furnace is shown in section in fig, 1039 : il differs but hitle tnaa a
puddling furnace. The whole interior, with the exception of the hearth a, is made of
1039 fire-brick I the beorlb is made
of sand. For this purpose a
pure siliceous sand is required i
^ tbe coarser the better. Tbe
bearth slopes considerably to-
wards the fine, the object of
which is to keep tbe bearth dry
and hard. Tbe iron wasted in
re-heating combines with ibe
silica of the sand, farming a
very fusible cinder, which Sows
off through the opening at b,
at which there is a small firv lo
keep tbe cinder liquid. The
-' thickness of the sand bottom it
IVom 6 to IS inches, resting on lire-brick; it generally requires rc-making after two
or three beats. The height of the fire-brick arch, or its distance from the sand
IRON. 593
bottom, is from 8 to 12 inches. The area of the fire-place averages 12 feet, and the
width of the Airnace varies from 5 to 8 feet When the piles are charged into the
furnace the door is shut, and fine coal is dusted around its edges to exclude the cold
air ; the temperature is raised to the highest intensity as quickly as possible, and
the workman turns the piles over from time to time that they may he brought to an
uniform welding heat in the shortest possible time.
It is thought by many that a purer iron is obtained by subjecting the balls as they
come out of the puddling furnace to the action of the hammer at first rather than to
the roughing rollers, as by the latter process vitrified specks remain in the metal,
which the hammer expels. Hence in some works the balls are first worked under
the forge hammer, and these stampings being afterwards heated in the form of pies or
cakes, piled over each other, are passed through the roughing mills.
Bars intended for boiler or tin plates are made from the best cold blast mine iron.
The raw pig is refined in the usual manner with coke, the loss amounting to from
2.^. to 3 cwts. per ton. It is then refined a second time with charcoal, the loss
amounting again to from 2^ to 3 cwts. per ton. After this second refining it is beaten
into flat plates white hot by the tilt hammer and thrown into cold water ; the sudden
chilling makes it more easily broken into small slabs. The slabs are piled in heaps
and welded in the hoUow fire, coke being the fuel ; the slabs are laid across the fire,
and do not come into contact with the fuel ; the blast is thrown under the fuel, and
the heat is immense ; when the piles are nearly at the fusing point, they are with-
drawn and passed under the rollers; they are again heated in the hollow fire, then
again rolled and heated a third time in the oidinary reverberatory furnace, after
which they are drawn out into flat bars for boiler plates, or for tin plate: the loss in
these operations amounts to from Sj to 4 cwt per ton. About 9 heats are ac-
complished in 12 hours, each heat consisting of 2^ cwts. of refined metal, and con-
suming 5 baskets of charcoal.
The bars intended for tin plates are repeatedly heated and rolled until of the
requisite thinness, the plates are then cut into squares, and annealed by exposing
tht-m for several hours to heat in covered iron boxes, being allowed to cool very slowly ;
this gives the plates the proper degree of pliancy. The next operation is that of
pickling ; the plates are immersed in dilute sulphuric acid for the purpose of re-
moving from their surfaces all oxide and dirt ; after remaining in the acid for the re-
quisite time, they are thoroughly washed in successive troughs of wati'r, and then
dried in sawdust ; finally the surfaces of the metal are prepared for the reception
of the tin, by rubbing them with leather upon cushions of sheepskin. The spent
sulphuric acid is run out into evaporating pans, and the sulphate of iron crystallised
out. In order to tin the plates, they are immersed in a bath of melted tin, the sur-
fietce of which is covered with tallow or palm oil ; when sufficiently covered, they
are transferred to the brusher on the left hand side of the tinner ; he passes a rough
brush rapidly over each side of the plate, whereby the superfluous tin is removed ; he
then plunges the plate again into the tin bath, and passes it on to his left hand neigh-
bour, who gives it a washing. The plate passes through several hands before it is
dried. Great skill is required in the tinning process ; nevertheless in a well-conducted
work the wasiers do not amount to more than 10 per cent ; a small percentage of
which are so bad as to require to be reworked. Great care is taken to avoid waste,
tin being worth 150/. per ton. A box of 225 sheets of tin plates 10 inches by
14 consumes about 8} lbs. of tin. See Tin Plate.
The processes pursued in the smelting works of the Continent have frequently in
view to obtain from the ore malleable iron directly, in a pure or nearly pure state.
The furnaces used for this purpose are of two kinds, called in French, 1. Feux de
Loupes, or Forges Catalanes; and 2. Foitmeaitx d piice, or Forges AUemandes.
In the Catalan, or French method, the ore previously roasted in a kiln is afterwards
strongly torrefied in the forge before the smelting begins ; operations which follow in
immediate succession. Ores treated in this way should be very fusible and very rich ;
such as black oxide of iron, hematites, and certain spathose iron ores. From 100
parts of ore, 50 of metallic iron have been procured, but the average product is 35.
The furnaces employed are rectangular hearths, ^s. 1040 and 1041, the water-blowing
machine being employed to give the blast See Metallurot. There are three
varieties of this forge ; the Catalan, the Navarrese, and the Biscay an. The dimensions
of the first, the one most generally employed, are as follows: 21 inches long, in the
direction pf.fig, 1041 ; 18^ broad, at the bottom of the hearth or creuset^ in the line
A B ; and 17 inches deep,^^. 1040. The tuyere, qp^ is placed 9 J inchesabove the bottom,
so that its axis is directed towards the opposite side, about 2 inches above the bottom.
But it must be movable, as its inclination needs to be changed, according to the stage
of the operation, or the quantity of the ores. It is often raised or lowered with pellets
of clay ; and even with a graduated circle, for the workmen make a great mystery of
Vol. II. Q Q
694
IRON.
this matter. The heurth is lined with a layer of Imuque (loam and cliarooal dut
worked together), and the ore after being roasted is sifted ; the small powder being set
aside to be used in the course of the operation. The ore is piled up on the side opposite
to the blast in a sharp saddle ridge, and it occupies one-third of the Idmaoe. In the
remaining space of two-thirds, the charcoal is put To solidify the imall ore on the
hearth, it is covered with moist cinders mixed with clay.
1040
1041
The fire is urged with moderation during the first two hours, the workman beng
continually employed in pressing down more charcoal as the former supply bvns
away, so as to keep the space full, and prevent the ore from crumbling down. By a
blast so tempered at the beginning, the ore gets well calcined, and partially reduced in
the way of cementation. But after two hours, the full force of the air is given;
at which period the fusion ought to commence. It is easy (o see whether the tarre-
faction be sufiSciently advance!, by the aspect of the fiame, as well as of the ore,
which becomes spongy or cavernous ; and the workman now completes the fusion, by
detaching the pieces of ore from the bottom, and placing them in fhmt of the tuyere.
When the fine siftings are afterwards thrown upon the top, they must be watered,
to prevent their being blown away, and to keep them evenly spread over the whole
surface of the light fuel. They increase the quantity of the produeta, and give a
proper fusibility to the seoriin. When the scorisB are viscid, the quantity of siftinp
must be diminished ; but if thin, they must be increased. The excess of shig is
allowed to run off by the chio or floss hole. The process lasts from five to six hours,
after which the pasty mass is taken out, and placed under a hammer to be eat into
lumps, which are afterwards forged into bars.
Each mass presents a mixed variety of iron and steel ; in proportions which may
be modified at pleasure ; for by using much of the siftings, and making the tuyere dip
towards the sole of the hearth, iron is the chief product ; but if the operation be cob-
ducted slowly, with a small quantiti^ of siftings, and an upraised tnylre, the quantity
of steel is more considerable. This primitive process is finvourably spoken of by
M. Brongniart The weight of the lump of metal varies from 200 to 400 pounds.
As the consumption of charcoal is very great, amounting in the Palatinate or Rhon-
kreis to seven times the weight of iron obtained, though in the Pyrenees it is only
thrice, the Catalan forge can be profitably employed only where wcKxi is exceedingly
cheap and abundant.
The Foumeaux djri^e of the French, or Stuck-ofen of the Germans, resemblesjE^i
675 (Copper) ; the tuyere (not shown there) having a dip towards the bottom of the
hearth, where the smelted matter collects. When the operation is finished, that is at
least once in every 24 hours, one of the sides of the hearth must be demolished, to
take out the pasty mass of iron, more or less pure. This furnace holds a middle
place in the treatment of iron, between the Catalsn forge and the cast -iron yfog»-^ea,
or high-blast furnaces. The stuck-ofen are fh>m 10 to 15 feet high, and about 3 feet
in diameter at the hearth. Most usually there is only one aperture for the tuyere and
for working ; with a small one for the escape of the slag ; on which aooount, the
bellows are removed to make way for the lifting out of the lump ci metal, which is
done through an opening left on a level with the sole, temporarily closed with bricks
and potter's day, while the furnace is in action.
This outlet being closed, and the furnace filled with charcoal, fire is kindled at the
bottom. Whenever the whole is in combustion, the roasted ore is introduced at the
top in alternate charges with charcoal, till the proper quantity has been introduced.
The ore falls down ; and whenever it comes opposite to the tuydre the slag begins to
flow, and the iron drops down and collects at the bottom of the hearth into the mass or
utuck : and in proportion as this mass increases, the Jlots -hole for the slag and the tny^re
is raised higher. When the quantity of iron accumulated in the hearth is Judged to
be sufficient, the bellows are stopped, the scoriss are raked o£^ the little brick wall is
taken down, and the mass of iron is removed by rakes and tongs. This mass is then
flattened under the hammer into a cake from 3 to 4 inches thick, and is cut into ttio
mON. £95
Inmpi, which are mbmitted to a nev openiion ; where it ii .treated in a pecDliu-
nflOBT;, lined with cb&rcDal iraigut, and eiposfd to a nearly horiiontal blut The
aboYe nuui teiied in tbe Jawi of powernil tongs, it heated befoni the luj^re ; ■ por-
tion of the melat flows down to tb« bottom of the hearth, loses its carbon lu a balh
at rich slags or flised oiidei, and formi thereby ■ mass of iron thoroughly reSoed.
Ilie portion thai ramains in the ton^ furnishes steel, which is drawn onl into ban.
This process is employed in Camiola for smelling a granular oxide of iron. The
mass or MlMck amoonts to from 13 to SO hundred- weight after each operalion of 24
hours. Eight strongmen are required to lift it ont, and to carry it nndera large hammer,
where it is cut bio pieces of about 1 cwt each. These are aflcrwards refined, and
dnwn into bun as aboie described. These furnaces are now almost generally aban-
doned on the Continent, in faToar of eharcoal high or blail/iimatt*.
Fig. lCMarepresent8aieAacA(o/en(bnt without the tnj^re, which may be supposed to
be in the tunsl place), and is, like all the conlinental ,„.„
Hmt* fonneatiJ'. remarkable tbr the eicessiTe thickness
of its masonry. The charge is put in at the throat, near
the mmmit of the octagonal or square cooeaTily, for they
are made of both forms. At the bottom of the hearth
(here is a dam-ilone with its plate, fbr permitting the
OTerflow of the slag, while it conflnes the subjacent fluid
melal : as well sa a tymp stone with its plate, which forms
the key to the front of the hearth ; the boshes are a wide
funnel, almost fla(, to obstmcl the easy descent of the
charges, whereby the smelting with ehorcnil wouM pro
ceed too rapidly. The bottom of the hearth is con-
structed of two large stones, and the hinder part of one II
great stone, called in German rflcijtein (back atone), which —
the French have corrupted into niiliiu. In other coun-
Iriea of the Continent, the boshes are frequently a good
deal more tapered downwards, and the hearth is hu*ger
than here represented. The refractory nature of the
Harts iron ores i« the reason assigned for this peen-
In Sweden there are blaat-ftimacea, ichacklo/ei, 35 feet in height, measured from
the boshes above the line of (he hearth, or craueL Their ovitv has the form of an
elongated ellipse, whose small diameter is 8 feet across, at a height of 11 feet above (he
bottom of the hearth { hence, at this part, the interior apaee constitutes a belly corre-
sponding with the upper part of the boshes. In other respects the details of the con-
strnctioD of the Swedish ftimacel resemble the one figured ahoie. Marcher relates
that a ftimace of that kind whose height was only 30 feet, in which brown hydrate of
iron (AtemifiM) was smelted, yielded 47 per cent in cast iron, at the rate of 5 hundred
weight a day, or 36 hnndred-weightone week alter another; and thai In the production
of 100 poond) of cast iron, 130 pounds of charcoal were consumed. That furnace
was worked with forge beliows, mounted with leather.
The decarhurotion of cast iron is merely a restoralitm of the carbon to the surface
in trocmg mreraelj the same progreMire steps as had carried it into the interior during
the smelling of the ore. The oiygeu of the air, acting first at the surrace of the
east metal npon the carbon which it finds there, bums il : freah charoosl, oozing
from (he interior, comes then to occupy the place of what had been dissipated ; till,
Anally, the whole carbon is transferred from the centre to the surlace, and is there
convened into either carbonic acid gas or oxide of carbon : for no direct experiment
has hitherto ^nroved which of these is the precise product of this combustion.
This diffnsibililT of carbon Ibroogb the whole mass of iron constitutes a movement
by means of which cost iron may be refined even without undergoing fusion, aa is
proved by a multitude of phenomena. Every workman has observed that steel loses
a portion of ita steely properties every time it Is healed in contact with air-
On the above principle, cost iron may be refined at one operation. Three kinds of
iron are susceptible of this continuous process ;— 1. The speckled cast-iron, which
cnntains snch a proportion of oxygen and carbon as with the oxygen of the air and
the carbon of the fuel may produce sufficient and complete saturation, bat nothing in
excess. 4. The dark grey cast-iron. 3. The white cast-iron. The nature of the
't metal requires variations both in the form of the fomaces, and in the mani-
Indeed malleable iron may be obtained directly from the ores by one (iision.
This mode of working is practised in the Pyrenees to a considerable eitent. All the
ore* of iron are not adapted for this operation. Those in which the meialUc oxide is
mixed with mooh earthy matter, do not answer well; but thoifl ounposed of the pure
596 lEON.
black oxide, red oxide, and carbonate, succeed much better. To extract the metal
from such ores, it is sufficient to expose them to a high temperature, in contact either
with charcoal, or with carbonaceoas gases; the metallic oxide is speedily rednced.
But when several earths are present, these tend continually, during the TitrificatioQ
-which they suffer, to retain in their yitreous mass the unreduced oxide of iron. Were
such earthy ores, as our ironstones, to be put into the low furnaces called Catalan^
through which ihe charges pass with great rapidity, and in which the oootact with
the fuel is merely momentary, there would be found in the crucible or hearth merely
a rich metallic glass, instead of a lump of metaL
la smelting and refining by a continuous operation, three different stages mar be
distinguished: — 1. The roasting of the ore to expel the sulphur, which would be less
easily separated afterwards. The roasting dissipates likewise the water, the carbonic
acid, and any other volatile substances which the minerals may contain. 2. The de-
oxidisement'and reduction to metal by exposure to charcoal or carburetted Tapoors.
3. The melting, agglutination, and refining of the metal to fit it for the heavy bammen
where it gets nerve. There are several forges in which these three operations seen
to be confounded into a single one, because, although still successive, they are prac-
tised at one single heating without interruption. In other forges, the processes are per-
formed separately, or an interval elapses between each stage of the work. Three
systems of this kind are known to exist:— 1. The Corsican method; 2. The Catalan
with wood charcoal ; and, 3. The Catalan with coke.
The farnaces of Corsica are a kind of semicircular basins, 18 inches in diameter,
and 6 inches deep. These are excavated in an area, or a small elcTaUon of masonry,
8 or 10 feet long by 5 or 6 broad, and covered in with a chimney. This area is quite
similar to that of the ordinary hearths of our blast-furnaces.
The tuyere stands 5 or 6 inches above the basin, and has a slight inclination down-
wards. In Corsica, and the whole portion of Italy adjoining the Mediterranean shores,
the iron ore is an oxide similar to the specular ore of the Isle of Elba. This ore con-
tains a little water, some carbonic acid!, occasionally pyrites, but in small quantity.
Before deoxidising the ore, it is requisite to expel the water and carbonic acid com-
bined with the oxide, as well as the sulphur of the pyrites.
The operations of roasting, reduction, fusion, and agglutination are executed in the
same furnace. These are indeed divided into two stages, but the one is a continoation of
the other. In the first, the two primary operations are performed at once; — the redac-
tion of a portion of the roasted ore is begun at the same time that a portion of the raw ore
is roasted : these two substances are afterwards separated. In the second stage, the de-
oxidisement of the metal is continued, which had begun in the preceding stage ; it Is
then melted and agglutinated, so as to form a ball to be submitted to the forge-hammer.
The roasted pieces are broken down to the size of nuts, to make the reduction of
the metal easier. In executing the first step, the basin and area of the furnace most
be lined with a hraiqve of charcoal dust, 3, 4, or even 5 inches thick: over this bra^qw
a mound is raised with lumps of charcoal, very hard, and 4 or 5 inches high. A
semicircle is ft>amed round the tuy6re, the inner radius of which is 5 or 6 inehea,
This mass of charcoal is next surrounded with another pile of the roasted and broken
ores, which must be covered with charcoal dust The whole is sustained with large
blocks of the raw ore, which form externally a third wall.
These three piles of charcoal, with roasted and unroasted ore, are raised in three
successive beds, each 7 inches thick : they are separated fh>m each other by a layer
of charcoal dust of about an inch, which makes the whole 24 inches high. This is
afterwards covered over with a thick coat of pounded charcoaL
The blocks of raw ore which compose the outward wall form a slope ; the larger
and stronger pieces are at the bottom, and the smaller in the upper parL The large
blocks are sunk very firmly into the charcoal dust, to enable them better to resist the
pressure from within.
On the bottom of the semicircular well formed within the charcoal lumps, kindled
pieces are thrown, and over these, pieces of black charcoal ; after which the blast of
a water-blowing machine (trompe) is given. The fire is kept up by constantly throw-
ing charcoal into the central well. At the beginning of the operation it is throst
down with wooden rods, lest it should affect the building ; but when the heat becomes
too intense for the workmen to come so near the hearth, a long iron rake is employed
for the purpose. At the end of about 3 hours, the two processes of roasting and
reduction are commonly finished : then the raw ore no longer exhales any fumes, snd
the roasted ore, being softened, unites into lumps more or less coherent.
The workman now removes the blocks of roasted ore which form the outer casing,
rolls them to the spot where they are to be broken into small pieces, and polls down
the brasque (small charcoal) which surrounds the mass of reduced ore.
The second operation is executed by cleaning the basin, removing the slags, covers
ing the basin anew with 2 or S brasques (coats of pounded charcoal), and piling up to
IRON. 597
the right and the left two heaps of charcoal dost. Into tbe interval between these
conical piles two or three baskets of charcoal are cast, and on its top some cakes of
the reduced crude metal being laid, the blast is resumed. Tbe cakes, as they heat,
undergo a sort of liquation, or sweating, by the action of the earthy glasses on the
unreduced black oxide present Very fusible slags flow down through the mass ; and
the iron, reduced and melted, passes finally through the coals, and falls into the slag
basin below. To the first parcel of cakes others are added in succession. In pro-
portion as the slags proceeding from these run down, and the melted iron falls to
the bottom, the thin slag is run off by an upper overfiow or chio hole, and the reduced
iron kept by the heat in the pasty condition, remains in the basin : all its parts get
agglutinated, forming a soft mass, which is remoYcd by means of a hooked pole in
order to be forged. Each lump or bioom of malleable iron requires 3 hours and a half
for its production.
The iron obtained by this process is in general soft, very malleable, and but little
steely. In Corsica four workmen are employed at one forge. The produce of their
labour is only about 4 cwt. of iron from 10 cwt of ore and 20 of charcoal, mingled
with wood of beech and chestnut. Though their ore contains on an arerage 65 per
cent of iron, only about 40 parts are extracted ; evincing a prodigious waste, which
remains in the slags.
The difference between the Corsican and the Catalonian methods consists in the
latter roasting the ore at a distinct operation, and employing a second one in the re^
duction, agglutination, and refining of the metal. In the Catalonian fofges, 100 pounds
of iron are obtained from 300 pounds of ore and 310 pounds of charcoal ; being a
produce of only 33 per cent It may be concluded that there is a notable loss, since
the sparry iron ores, which are those principally smelted, contain on an average from
.54 to 56 per cent of iron. The same ores smelted in the ordinary blast furnace
produce about 45 per cent of cast iron.
On the Continent, iron is frequently refined firom the cast metal of the blast fur-
naces by three operations, in three different ways. In one, the pig being melted,
with aspersion of water, a cake is obtained, which is again melted in order to form
a second cake. Thia being treated in the refinery fire, is then worked into a blown.
In another system, the pig iron is melted and cast into plates : these are melted anew
in order to obtain crude balls, which are finally worked into blooms. In a third mode
of manufacture, the pig-iron is melted and cast into plates, which are roasted, and
then strongly heated, to form a bloom.
The French fusible ores, such as the silicates of iron, are very apt to smelt into
white cast iron. An excess of fluxes, light charcoals, too strong a blast, produce the
same results. A surcharge of ores which deranges the furnace and affords impure
slags mixed with mach iron, too rapid a slope in the boshes, too low a degree of heat,
and too great condensation of the materials in the upper part of the furnace ; all tend
also to produce a white cast iron. In its state of perfection, white cast iron has a
silver colour, and a bright metallic lustre. It is employed frequently in Germany for
the manufacture of steel* and is then called steel floss, or lamellar floss, a title which
it still retains, though it be hardly silver white, and has ceased to be foliated. When
its colour takes a bluish grey tinge, and its fracture appears striated or splintery, or
when it exhibits grey spots, it is then styled flower floss. In a third species of white
cast iron we observe still much lustre, but its colour verges upon grey, and its texture
is variable. Its Aracture has been sometimes compared to that of a broken cheese.
This variety occurs very frequently. It is a white cast iron, made by a surcharge of
ore in the furnace. If the white colour becomes less clear and turns bluish, if its
fracture be contorted, and contains a great many empty spaces or air-cells, the metal
takes the name of cavemotts-flossy or tender floss. The whitest metal cannot be em-
ployed for casting. When the white is mixed with the grey cast iron, it becomes
riband or trout cast iron.
The German refining forge, — Fig9, 1043, 1044, represent one of the numerous refinery
furnaces so common in the Hartz. The example is taken ftrom the MandelhoHz works,
in the neighbourhood of Elbingerode. Fig, 1044 is an elevation of this forge, d is the
refinery hearth, provided with two pairs of bellows. Fig. 1043 is a vertical section,
showing particularly the construction of the crucible or hearth in the refinery forge d.
c is an overshot water wheel, which gives an alternate impulsion to the two bellows a b
by means of the revolving shaft c, and the cams or tappets dfeg,
D, fhe hearth, is lined with cast-iron plates. Through the pipe /, cold water may be
introduced, under the bottom plate m, in order to keep down, when necessary, the tem-
perature of the crucible, and facilitate the solidification of the loupe or bloom. An ori-
fice n^figs, 1043, 1044, called the chio (floss hole), allows the melted slag or cinder to
flow off from the surface of the melted metal. A copper pipe or nose piece conducts
the blast of both hallows into the hearth, as shown at b x,fig, 1044.
Q Q 3
698
IRON.
The substanoe subjected to tbii mode of refinery i§ a grej earbonaoeom east irao,
from the works of RothehutCe. The hearth i>, being filled and hei^ied oyer with lire
charcoal, upon the side opposite to the tayhre x^fi^. 1043, 1P44, long pigs ofcaatinm
are laid with their ends sloping downwards, and are drawn forwards saccesBWely into
the hearth by a hooked poker, so that the extremity of each may be plunged into
the middle of the fire, at a distance of 6 or 8 inches fh>m the month of the toyere.
The workman proceeds in this way till he has melted enough of metal to form aimpe.
The cast iron, on melting, falls down in drops to the bottom of the hearth ; h&ng
covered by the fused slags, or yitreous matters more or less loaded with oxide of inn.
After running them off by the orifice n, he then works the cast iron by powerful stir-
ring with an iron rake (ringard)^ till it is conyerted into a mass of a pasty ocmsistenee.
During this operation, a portion of the carbon contained in the cast iron combines
with the atmospherical oxygen supplied by the bellows, and passes off in the form of
carbonic oxide and carbonic acid. When the lump is coagulated sufficiently, the
workman turns it over in the hearth, then increases the heat so as to melt it aDresh,
meanwhile exposing it all round to the blast, in order to consume the remainder of
the carbon, that is, till the iron has become ductile, or refined. If one fiouuoii shoald
prove inadequate to this effect, two are given. Before the conclusion, the workman
runs off a second stratum of vitreous slag, but at a higher level, so that some of it may
remain upon the metaL
The weight of such a loupe or bloom is about 2 cwts., being the product of 9 cwts.
and ^ of pig iron ; the loss of weight is therefore about 26 per cent 149 pounds of
charcoal are consumed for every 100 pounds of bar iron obtained. The whole ope-
ration lasts about 5 hours. The bellows are stopped as soon as the bloom is ready ;
this is immediately transferred to a forge hammer, the cast-iron head of whieh
weighs 8 or 9 cwts. The bloom is greatly condensed thereby, and dischai^gcs a
considerable quantity of semi-fluid cinder. The lump is then divided by the hammer
and a chisel into 4 or 6 pieces, which are re-heated, one after another, in the same
refinery fire, in order to be forged into bars, whilst another pig of cast iron is laid in
its place, to prepare for the formation of a new bloom. The above process is called
by the Germans hlump-frischen, or lump refining. It differs from the daareh ■hnek-
frificken, because in the latter the lump is not turned over in mass, but is broken,
and exposed in separate pieces successively to the refining power of the blast near the
tuyere. The French call this affincigeparportums; it is much lighter work than the ocker.
The quality of the iron is tried in various ways ; as, first, by raising a bar by one
end, with the two hands over one's head, and bringing it forcibly down to strike
across a narrow anvil at its centre of percussion, or one-third from the other extre-
mity of the bar ; after which it may be bent backwards and forwards at the place of
percussion several times ; 2, a heavy bar may be laid obliquely over props near iu
end, and struok strongly with a hammer with a narrow pane, so as to curve it in <^
posite directions ; or while heated to redness, they may be kneaded backwards and
forwards at the same spot, on the edge of the anvil. This is a severe trial, which the
hoop L, Swedish iron, bears surprisingly, emitting as it is hammered a phosphoric
odour, peculiar to it and to the bar iron of Ulverstone, which also resembles it in fiir-
nishing a good steel. The forging of a horse-shoe is reckoned a good criterion of the
quality of iron. Its freedom fh>m flaws is detected by the nhave modes ; and its
linear strength may be determined by suspending a scale to the lower end of a hard-
drawn wire, of a given size, and adding weights till the wire breaks. The treatises
of Barlow, Tredgold, Hodgkinson, and Fairbairn may bo consult^ with advanta^
IRON. 699
on the methods of proring the ttrength of difTerent kinds of iron, in a great variet j of
circnmatances.
Dry oMacttf of iron ores, — The object of a dry asaay of an iron ore is to ascertain
by an experiment on a small scale the amoont of iron which the ore should yield
when smelted on the large scale in the blast fnmace. For this purpose the metal
most be deoxidised, and such a temperature produced as to melt Uie metal and the
earths associated with it in the ore, so that the former may be obtained in a dense
button at the bottom of the crucible, and the latter in a lighter glass or slag above it.
Such a temperature can only be obtained in a wind fiimace connected with a chimney
at least 30 feet in height, and when made expressly for assaying the fiimace, is gene-
rally built of such a size that four assays may be made at the same time, viz. about
14 inches square, and S feet in depth from the under side of the cover to the moveable
bars of iron which form the grate. In order that the substances associated with the
iron in the ore should form a fhsible compound, it is usually requisite to add a flux,
the nature of which will depend upon the character of >he ore under examination.
Berthier divides iron ores into five classes : 1. The almost pure oxides, such as the
magnetic oxide, oligietie iroHt and the hamatites; 8. Ores containing silica, but free or
nearly so from any other admixture ; 3. Ores containing silica and various bases, but
'little or no lime ; 4. Ores containing one or more bases, such as lime, magnesia, aiumina,
oxide o/manganeee, oxide of titanium, oxide of tantalum, oxide of chromium, or oxide of
tungetem, but little or no euica ; 5. Ores containing silica, lime, and another base, and
which are fusible alone. Ores of the first class may be reduced without any flux,
but it is always better to employ one, as it greatly facilitates the formation of the
button ; borax may be used, or, better, a fusible earthy silicate, such as ordinary flint
glass. Ores of the second class requh^ some base to serve as a flux, such as carbonate
of soda, a mixture of carbonate of lime and clay, or of carbonate of lime and dolomite :
ores of the third class are mixed with carbonate of lime in the proportion of from one-
half to three-fourths of the weight of the foreign matter present in the ore. Ores of
the fourth class require as a finx silica in the form of pounded quartz, and generally
also some lime ; the manganesian spathic ores which belong to this class may be
assayed with the addition of silica alone, but the magnesian spathic ores require lime.
Ores of the fifth class require no flux.
Method of conducting the assay, — One hundred grains of the ore finely pulverised
and passed through a silk sieve are well mixed wi& the flux, and the mixture intro-
duced into the smooth concavity made in the centre of a crucible that has been lined
with charcoal ; the lining of the crucible is effected by partially fUling it with coarsely
powdered and slightly damped charcoal or brasque, which is then rammed into a
solid form by the use of a light wooden pestle. The mingled ore and flux must be
covered with charcoaL The crucible thus filled is closed with an earthen lid luted
on with fire clay ; and it is then set on its base in the air fUrnace. The heat should
be very slowly raised, the damper remaining closed during the first half-hour. In *
this way the water of the damp charcoal exhales slowly, and the deoxidation of the
ore is completed before the fbsion begins : if the heat were too high at firat the luting
would probably split, and moreover, the slag formed would dissolve some oxide of
iron, which would be lost to the button, and thus give an erroneous result After
half an hour the damper is gradually opened, and the fiimace being filled with fresh
coke, the temperature is raised progressively to a white heat, at which pitch it must
be maintained ftr a quarter of an hour; the damper is then closed and the furnace is
allowed to cool. As soon as the temperature is sufliciently reduced, the crucible is
removed and opened over a sheet of brown paper ; the hrcique is carefully removed,
and the button of cast iron taken out and weighed. If the experiment has been
entirely successful the iron will be found at the bottom of the crucible in a small
rounded button, and the slag will be entirely free from any adhering metallic globules,
and will resemble in appearance green bottle glass ; should, however, the slag contain
small metallic particles, the experiment is not necessarily a failure, as they may
generally be recovered by washing and the magnet. But if on breaking the cracible,
the reduced metal should be found in a partially melted state and not collected into a
distinct mass, it indicates either too low a temperature or an improper selection of
fluxes, and the experiment must be repeated. The iron obtained is not chemically
pure, but contains carbon, and if the ore is man^pmiferous, manganese ; the result is
therefore somewhat too high, though indicating with sufficient exactness for all manu-
facturing purposes the richness of the ore assayed.
Humid astay of iron ores, — The quantitative determination of the various sub-
stances that occur in iron ores, demands on the part of the operator a considerable
amount of skill and patience, and can only be profitably undertaken by those who
have acquired in the laboratory a thorough acquaintance with analytical operations.
As, however, much attention has of late years been bestowed on the comfvition of
QQ4
1
600 .IRON.
iron ores, and as certain elements, tIz. manganese, auJphvr, and pho^phonu^ are
frequently present, which very considerably affect their commercial value, we deem
It right to give a detailed account of the operations to be performed in order to arrive
at an accurate knowledge of the composition of an ore.
Taking for illustration a specimen of the most complicated eompoaitioD, the
substances besides iron to be looked for, and estimated, are water (h^proKopfie and
combined)^ organic matter^ sulphur (as sulphuric acid, and as bisulphide of irony, pkos-
phoric acid, carbonic acid, gilicic add, oxide of manganese, ahtmina, lime, and alkalies:
lead, tin, copper, and arsenic, are also occasionally met with ; these metals are sought
for when a suspicion of their presence is entertained by a special operatioQ on a lai^
quantity of ore.
Too great care cannot be bestowed on the sampling of ores intended for analysis ;
to expend so much time and labour on an isolated specimen (unless for a special
object) is worse than useless ; the sample operated upon should be selected from a
large heap, which should be thoroughly gone over, and several dozen pieces taken frnm
different parts ; these should be coarsely powdered and mixed, and about half a ponad
taken from the mass should be preserved in a well corked bottle for examination.
1. Determination of water (fygroscopic and combined), — About 50 grains of the
ore are dried in the water oven till no further loss of weight is experienced ; the loss
indicates the hygroscopic water ; the residue is introduced into a tube of hard ^laas,
to which is adapted a weighed tube containing chloride of calcium ; the powder is
then gradually raised to a low red heat, the combined water is thereby expelled, and
its amount determined by the increase in weight of the chloride of caleiam tabe.
Some ores (the hydrated hsematites) contain as much as 12 per cent of combined watez.
2. Sulphuric acid and sulphur. — From 30 to 50 grains of the ore are digested with
hydrochloric acid, filtered and washed. The filtrate, concentrated if necessary by
evaporation, is precipitated by great excess of chloride of barium. Every 100 parts
of the sulphate of baryta produced indicate 34*37 parts of sulphuric aci^ The in-
soluble res-due on the filter is fused in a gold crucible with nitre and carbonate of
soda, the fused mass is dissolved in hydrochloric acid, evaporated to dryness, mois-
tened with strong acid, diluted and filtered ; from the filtrate the sulphuric acid is
precipitated as sulphate of baryta, every 100 parts of which indicate IS'748 parts of
sulphur, and 25*48 parts of bisulphide of iron.
In the analysis of haematites it is necessary to bear in nund that perehloride of iron
is partially reduced when boiled with finely divided iron pyrites and hydrochlorie
acid, sulphuric acid being formed. — Dich,
Phosphoric acid. — From 50 to 75 grains of the ore are digested with hydrochlorie
acid and filtered ; the clear solution, which should not be too acid, is boiled wiih
sulphite of ammonia, added gradually in small quantities till it either becomes eoloar-
less, or acquires a pale green colour, indicating that the peroxide of iron originally
• present has been reduced to protoxide ; the solution is nearly neutralised widi car-
bonate of ammonia, excess of acetate of ammonia added, and the liquid boiled ; strong
solution of perehloride of iron is then added drop by drop, until the precipitate which
forms has a distinct red colour; this precipitate, which contains all the phosphoric acid
originally present in the ore, is collected on a filter, washed, and redissolved in hydro-
chloric acid, tartaric acid added, and then ammonia. From this ammoniacal solution,
the phosphoric acid is finally precipitated as ammonio-phosphate of magnesia, by the
addition of chloride of ammonium, sulphate of magnesia, and ammbnia. The pre-
cipitate is allowed 24 hours to subside, it is then collected on a filter, and if it has a
yellow colour, which is almost invariably the case, it is redissolved in hydrochloric add,
and more tartaric acid being added, it is again precipitated by ammonia: 100 parts of
the ignited pyrophosphate of magnesia correspond to 64'3 parts of phosphoric acid.
Alkalies. — It was ascertained by Mr. Dick, that nearly the whole of the alkali
present in an iron ore are contained in that portion which is insoluble in hydro-
chloric acid. The residue from about 50 grains of the ore is placed in a plufinnm
capsule, moistened with ammonia, and exposed for several hours to the action of
hydrofluoric acid gas in a closed leaden dish ; it may be necessary to repeat the ope-
ration if much silica is present ; it is then slowly heated to dull redness, and dis-
solved in dilute hydrochloric acid \ the solution is mixed with excess of baryta water
and filtered ; the excess of baryta is removed by carbonate of ammonia, and the so-
lution is evaporated to dryness and ignited ; the residue is redissolved in a little hot
water, and a few drops of oxalate of ammonia added. If no precipitate or cloudiness
occurs, it may be once more evaporated to dryness and gently ignited: the residue
is chloride of potassium, 100 parts of which indicate 63 parts of potash. Should
oxalate of ammonia have occasioned a precipitate, it must be filtered off, and the
clear liquid evaporated. The search for potash is troublesome and lengthy ; it may
be altogether omitted in a technical analysis.
IRON. 601
DetermnaHcn of the renuuning constiiuentB. -^ 25 or 30 gniDS of tbe finely powdered
ore are digested for about half an hour -with strong hydrochloric acid, diluted with
boiling distilled water and filtered. The residue on the filter being thoroughly washed,
tbe solution is peroxidised, if necessary, by the addition of chlorate of potash, nearly
neutralised by ammonia, boiled with excess of acetate of ammonia, and rapidly
filtered while hot ; the filtrate (which should be colourless) together with the wash-
ings, is received in a flask, ammonia is added, and then a few drops of bromine, and
the flask closed with a cork. In a few minutes, if manganese be present, the liquid
acquires a dark colour ; it is allowed to remain at rest for 24 hours, then warmed»
and rapidly filtered and washed ; the brown substance on the filter is hydrated oxide
of manganese: it loses its water by ignition, and then becomes Mn* O*, 100 parts of
which correspond to 93 parts of protoxide.
The liquid filtered from the manganese contains the lime and magnesia; the former
IS precipitated by oxalate of ammonia, and the oxalate of lime formed converted by
ignition into carbonate, in which state it is either weighed, haying been previously
evaporated with carbonate of ammonia, or it is converted into sulphate by the ad-
dition of a few drops of sulphuric acid, evaporation, and ignition. The lime being
separated, the magnesia is thrown down as ammonio-magnesian phosphate by phos-
phate of soda and ammonia, and after standing for 24 hours it. is collected on a filter,
washed with cold ammonia water, dried, ignited, and weighed ; 1 00 parts of car-
bonate of lime correspond to 56*0 of lime; 100 parts of sulphate of lime to 40*1 of
lime, and 100 parts of pyrophosphate of magnesia to 35*7 of magnesia.
The red precipitate collected on the filter after the boiling with acetate of am-
monia, consists of the basic acetates of iron and altiminOj together with the phosphoric
acid. It is dissolved in a small quantity of hydrochloric acid, and then boiled in a
silver or platinum basin with considerable excess of pare caustic potash ; the alumina
(with the phosphoric acid) is hereby dissolved, the insoluble portion is allowed to
subside, and the clear liquid is then decanted, after which the residue is thrown on a
filter and washed ; the filtrate and washings are supersaturated with hydrochloric
acid, nearly nentralised with ammonia, and the alumina finally precipitated by car-
bonate of ammonia. From the weight of the ignited precipitate, the corresponding
amount of phosphoric acid determined by a separate operation is to be dedncted, the
remainder is calculated as alumina. The residue left after digesting the ore with
hydrochloric acid, consists principally of ailicOf but it may also contain alumina^ per-
oxide of iron, lime, magnesia, and potash. For practical purposes it is rarely necessary
to submit it to minute examination ; should such be desired, it most be dned, ignited,
and weighed, then fused in a platinum crucible with four times its weight of mixed
alkaline carbonates, the fused mass dissolved in dilute hydrochloric acid, and evapo-
rated to dryness, the residue moistened with strong hydrochloric acid, and after stand-
ing at rest for some hours, digested with hot water, filtered, and the silica on the filter
ignited and weighed. The alumina, lime, oxide of iron, and magnesia in the filtrate are
separated from each other according to the instructions given above ; the potash is esti-
mated by a distinct process.
Carbonic acid. — This acid, which constitutes a considerable part of the weight of
that large and important class of ores the clap ironstones^ is estimated by noting the
loss sustained after adding to a weighed portion of the ore sulphuric acid, and thus
evolving the gas; or more roughly, by the loss sustained in the entire analysis.
Another method is to fuse 20 or 25 grains of the ore with 60 or 80 grains of dry
borax, and noting the loss, which consists of water and carbonic acid ; by deducting
the water obtained in a previous experiment, the quantity of carbonic acid is ob-
tained. This method, however, can scarcely be recommended, on account of the cor-
rosion of the crucible, though the results are very accurate.
Determination of the iron. — This is performed on a separate portion of the ore,
either by the volumetric method of Marguerite, or by that of Dr. Penny : both give
very exact results. Marguerite's method is based on the reciprocal action of the
salts of protoxide of iron and permanganate of potash, whereby a quantity of the
latter is decomposed exactly proportionate to the quantity of iron. The ore
(about 10 or 15 grains) is dissolved in hydrochloric acid, and the metal brought to
the minimum of oxidation by treating the solution with sulphite of soda (or better,
sulphite of ammonia), and boiling to expel the excess of sulphurous acid ; the solution
of permanganate of potash is then cautiously added drop by drop, until the pink
colour appears, and the number of divisions of the burette required for the purpose
accurately noted. The solution should be considerably diluted, and there must be a
sufficient quantity of free acid present to keep in solution the peroxide of iron formed
and also the oxide of manganese. The whole of the iron must be at the minimum
of oxidation, and the excess of sulphurous acid must be completely expelled ; if
the latter precaution be neglected an erroneoirs result will be obtained, as the sul-
602 IRON.
pharoos acid wiU itself take oxygen firom the permanganic acid, and thai reaet in
the same manner as iron.
To prepare the permanganate of potash, 7 parts of chlorate of potassse, 10 parts of
hydrate of potassa, and 6 parts of peroxide of manganese are indmately mixed. The
manganese must be in the finest possible powder, and the potash having been dis-
solved in water, is mixed with the other substances, dried, and the whole heated to
very dull redness for an hour. The fused mass is digested with water, so as to obtain
as concentrated a solution as possible, and dilute nitric acid added till the eoloor
becomes of a beautiful yiolet ; it is afterwards filtered through asbestos. The solndoD
must be defended from the contact of organic matter, and kept in a glass stoppered
bottle. If the solution be eyaporated it yields beautifiil red acicnlar crystals : it is
better to employ the crystals in the preparation of the test liquor, as the solution keeps
Inuch better when no manganate is present To prepare Uie normal or test liquor,
a certain quantity, say 15 grains, of piano-forte wire are dissoWed in pure hydro-
chloric acid ; after the disengagement of hydrogen has ceased, and the solution is
complete, the liquor is diluted with about a pint of water, and aoeurately divided by
measurement into two equal parts, the number of burette divi«ons of the solution of
permanganate required to produce in each the pink colour is accurately noted ; snd
this number is then employed to reduce into weight the result of the analysis of an
ore. A useful normal liquor is made by dissolving 100 grains of the crystallised
permanganate in 10,000 grains of water.
Penny's method is based on the reciprocal action of chromic acid and protoxide of
iron, whereby a transference of oxygen takes place, the protoxide of iron becoming
converted into peroxide, and the chromic acid into sesquioxide of chromium. The
process is conducted as follows : — A convenient quantity of the specimen is reduced
to coarse powder, and one half at least of this is still further pulrerised antil it is no
longer gritty between the fingers. The test solution of bichromate of potash is next
prepar A : 44*4 grains of this salt In fine powder are weighed out, and pnt into a
burette graduated into 100 equal parts, and warm distilled water is afterwards poured
in until the instrument is filled to 0. The palm of the hand is then securely |4aeed
on the top, and the contents agitated by repeatedly iuTertlng the instrument until the
salt is dissolved and the solution rendered of uniform density throughout. Each divi-
sion of the solution thus prepared contains 0-444 g^ins of bichromate, which Dr.
Penny ascertained to correspond to half a grain of metallic iron. The bichromate
must be pure, and should be thoroughly dried by being heated to incipient fusion.
100 grains of the pulverised iron-stone are now introduced into a Florence flask with
1^ oz. by measure of strong hydrochloric acid and ^ oz. of distilled water. Heat is
cautiously applied, and the mixture occasionally agitated until the effervescence
caused by the escape of carbonic acid ceases, the heat is then increased, and the mix-
ture made to boil, and kept at moderate ebullition for ten minutes or a quarter of an
hour. About 6 oz. of water are next added and mixed with the contents of the flask,
and the whole filtered into an evaporating basin. The fiiask is rinsed several times
with water, to remoTC all adhering solution, and the residue on the filter is well washed.
Several small portions of a weak solution of red prussiate of potash (containing 1
part of salt to 40 water) are now dropped upon a white porcelain slab, which is
conveniently placed for testing the solution in the basin during the next operation.
The prepared solution of bichromate of potash in the burette is then added Tery
cautiously to the solution of iron, which must be repeatedly stirred, and as soon as it
assumes a dark greenish shade it should be occasionally tested with the red prussiate
of potash. This may be easily done by taking out a small quantity on the end of a glass
rod, and mixing it with a drop of the solution on the porcelain slabb When it is noticed
that the last drop communicates a distinct blue tinge, the operation is terminated ; the
burette is allowed to drain for a few minutes, and the number of divisions of the test
liquor consumed read off. This number multiplied by 2 gives the amount of iron
per cent The necessary calculation for ascertaining the corresponding quantity of
protoxide is obvious. If the specimen should contain iron in the form of peroxide,
the hydrochloric solution is deoxidised as before by sulphite of ammonia. Tiie pre-
sence of peroxide of iron in an ore is easily detected by dissolving SO or 40 grains in
hydrochloric acid, diluting with water, and testing a portion of the solution with sul-
phocyanide ofpotoMium. If a decided blood-red colour is produced, peroxide of iron
is present If it be desired to ascertain the relative proportions of peroxide and
protoxide of iron in an ore, two operations must be performed : one on a quantity of
the ore that has been dissolved in hydrochoric acid in a stout stoppered bottle ; and
another on a second quantity that has been dissolved as usual, and then deoxidised by
sulphite of ammonia or by metallic zinc. It is advisable to employ the solution of
bichromate much weaker than proposed by Dr. Penny, and to employ a burette
graduated to cubic millimorres. A good strength is 1 grain of metallic iron a 10
cubic centimetres of bichromate.
IRON. 603
Metalaprecipitable by sulphurHted Hydrogen from the hydrochbrie •o/vfum.^-A weighed
portion of the ore Tarying from 200 to 2000 grains is digested for a considerable time
in hydrochloric acid: the solution is filtered off; the iron in the filtrate redncedwhen
necessary by solphtte of ammonia, and a current of sulphoretted hydrogen i>a88ed through
it. A small quantity of sulphur which is always suspended is collected on a filter and
thoroughly washed ; it is then incinerated at as low a temperature as possible. The
residue (if any) is mixed with carbonate of soda and h«»ted upon charcoal before the
blowpipe : any globules of metal that may bo obtained are dissolved and tested.
Anafyeis of pig iron, — The most impwtant constituents to be determined are carbon
(combined and uncombined), silicon, eulphur, phoephorus; those of less consequence,
or of more rare occurrence, are nutnganeee, tiraenic, copper, zinc, chromium, titanium,
cobalt, nickd, tin, altanintan, calcium, magnenum, and the metaU of the aikaliee,
1. Dettmdnaiion of the total anumnt of carbon, — ^About 100 grains of the iron in
small pieces are digested, at a moderate temperature, in 6-os. measures of a solution
formed by dissolying 6 oz. of crystallised sulphate of copper, and 4 oz. of common
salt in 20 oz. of water and 2 oz. of concentrated hYdrochlorio acid. The action is
allowed to proceed until all, or nearly all the iron is dissolved. Carbon and copper
are left insoluble ; these are collected on a filter, and washed first with dilute hydro-
chloric acid (to prevent Uie precipitation of sub-chloride of copper), then with water,
then with dilute caustic potash, aud finally with boiling water. The mixed carbon
and copper are dried on the filter, fh>m which they are easily removed by a knife
blade, and are mixed with oxide of copper, and burned in a combustion tube in the
usual way, with a current of air, or, still better, of oxygen. The carbonic acid is col-
lected in Liebig*s apparatus, from which the amount of carbon is calculated.
2. Graphite, or uncombined carbon, — A weighed portion of the finely divided iron
(filings or borings may be used) is digested with moderately strong hydrochloric
acid, the combined carbon is CToWed in combination with hydrogen, while the
graphite is left undissolved. It is collected on a filter, washed, and then boiled
with a solution of caustic potash, sp. gr. 1-27, in a silver dish ; the silica which
existed in the iron in the form of silicon is hereby dissolved ; the clear caustic solu-
tion is drawn off by a pipe or syphon, and the black residue repeatedly washed ; it
is dried at as high a temperature as it will bear, and weighed ; it is then heated to
redness in a current of air, until the whole of the carbon is burnt off. A reddish re-
sidue generally remains, which is weighed, and the weight deducted from that of
original black residue, the difference gives the amount of graphite.
3. Silicon — The amount of this element is determined by evaporating to dryness
a hydrochloric solution of a weighed quantity of the metal : the dry residue is re*
digested with hydrochloric acid, diluted with water, boiled and filtered ; the insoluble
matter on the filter is washed, dried and ignited, until the whole of the carbon is
boiled off; it is then weighed, sfter which, it is digested with solution of potash, and
the residue, if any, wash^, dried, ignited, and weighed: the difference between the two
weights gives the amount of silicic acid, 100 parts of which indicate 47 parts ofeiUcon,
Phosphorus, — ^A weighed portion of the metal is digested in nitro-hydrochloric acid,
evaporated to dryness, and the residue re-digested with hydrochloric acid. The solution
18 treated precisely as recommended for the determination of phosphoric acid in ores ;
every 100 parts of pyrophosphate of magnesia indicate 28'56 parts of phosphorus.
Sulphur, — In grey iron this element is very conveniently and accurately estimated
by allowing the gas evolved by the action of hydrochloric acid on a weighed quantity
(about 100 grains) of the metal, in filings or borings, to pass slowly through a solution
of acetate of lead acidified by acetic acid : the sulphur, the whole of which takes the
form of sulphuretted hydrogen, enters into combination with the lead, forming a black
precipitate of sulphide of lead, which is collected, washed, and converted into sulphate of
lead by digesting it with nitric acid, evaporating to dryness, and gently igniting :
100 parts sulphate of lead «■ 10-55 sulphur. The most minute quantity of sulphur in
iron is detected by this process. If, however, crude white iron is under examination,
this method does not give satisfactory results, on account of the difficulty with which
it is acted upon by hydrochloric acid ; It is better, therefore, to treat the metal with
nitro-hydrochloric acid, evaporate to dryness, re-digest with hydrochloric acid, and then
precipitate the filtered solution with great excess of chloride of barium ; or the finely
divided metal may be fused in a gold crucible with an equal weight of pure nitrate of
soda and twice its weight of pure alkaline carbonates ; the fused mass is extracted
with water acidified with hydrochloric acid, and finally precipitated by chloride of
barium.
Manganese, — This metal is determined b^ the process described for iu estimation
in ores ; the iron must exist in the solution in the form of sesquioxide.
Arsenic and copper. — The nitro-hydrochloric solution of the metal is^ evaporated
to dryness, re-digcsted with hydrochloric acid, and filtered. The iron in the clear
604 ISINGLASS.
solution is reduced to protocUoride by boiling with a sufficient qnantitj of solpliite
of ammonia, the solatioo is boiled till it has lost all smell of salphnrous acid« It is
then saturated with sulphuretted hydrogen, and allowed to stand for 24 hours in a
closed vessel, the excess of gas is boiled oft, and the precipitate, if any, collected on a
small filter and well wash^ ; it is digested with monosulphide of potassium, which
dissolves the salphide of arsenic, leaving the sulphide of copper untouched ; the
latter is decomposed by heating with nitric acid, and the presence of copper evinced
by the addition of ammonia, which produces a fiue blue colour ; the sulphide of
arsenic is precipitated from its solution in sulphide of potassium by dilute snlphnrie
acid ; it may be redissolved in aqua regia, and the nitric acid having been expelled by
evaporation, the arsenic may be reduced in Marsh's apparatus.
Nickel ank cobalt, — These metals, if present, will be found in the solution from which
the copper and arsenic have been precipitated by sulphuretted hydrogen. The solutioQ
is peroxidised, and the sesquioxide of iron precipitated by slight excess of carbonate
of baryta, after which the nickel and cobalt are precipitated by sulphide of ammonium.
Chromium and vanadium, — These metals which should be looked for in the car*
bonaceous residue obtained by dissolving a large quantity of the iron in dilute hy-
drochloric or sulphuric acid are detected as follows ( WShler) : — The ignited residue
is intimately mixed with one-third of its weight of nitre, and exposed tor an hour in
a crucible to a gentle ignition. When cool, the mass is powdered and boiled with
water. The filtered solution is gradually mixed and well stirred with nitric acid,
taking care that it may still remain slightly alkaline, and that no nitrous acid is
liberated which would reduce the vanadic and chromic acids. The solution is then
mixed with an excess of solution of chloride of barium as long as any precipitate is
produced. The precipitate, which consists of vanadiate and chromate of baryta, is
decomposed with slight excess of dilute sulphuric acid, and filtered. The filtrate is
neutralised with ammonia, concentrated by evaporation, and a fragment of chloride
of ammonium placed in it In proportion as the solution becomes saturated with
chloride of ammonium, vanadate of ammonia is deposited as a white or yellow
crystalline powder. To test for chromium only, the mass after fusion with nitre it
extracted with water, and then boiled with carbonate of ammonia ; the solution is
neutralised with acetic acid, and then acetate of lead added ; the production of a
yellow precipitate indicates chromic acid.
Aluminium, — This metal is best separated from iron, by first reducing the latter to
the state of protoxide by sulphite of ammonia, then neutralising with carbonate of
soda, and afterwards boiling with excess of caustic potash, until the precipitate is
black and pulverulent. The solution is then filtered oft, slightly acidulated with
hydrochloric acid, and the alumina precipitated by sulphide of ammonium.
Calcium and magnesium, — These metals are found in the solution from which
the iron and aluminium have been separated ; they both exist probably (together with
the aluminium) in the cast iron in the form of slagj and are best detected in the black
residue which is left on dissolving the iron in dilute sulphuric or hydrochloric acid.
After digesting this residue with caustic potash, and burning away the graphite, a small
quantity of a red powder is left, which is composed of silicic acid, oxide of iron,
alumina, lime, and magnesia ; if 500 grains of cast iron are operated upon, a suffix
cieni quantity of insoluble residue will be obtained for a quantitative determinatioa of
its constituents. — H. M. N.
IRONBRIDGB. See Tubes.
ISINGLASS {CoUe de Poisson, Fr. ; ffausenblaee. Germ.), IchthyocoUa, Ix^vamiKKa,
from ix^^s^ a fish, and KtJXXa, glue, or Fish glue, is a whitish, dry, tough, semi-trans-
parent substance, twisted into different shapes, often in the form of a lyre, and
consisting of membranes rolled together. Good isinglass is unchangeable in the air,
has a leathery aspect, and a mawkish taste, nearly insipid ; when steeped in cold water
it swells, softens, and separates in membranous lamina:. At the boiling heat it dis-
solves in water, and the solution, on cooling, forms a white jelly, which is semi-tnna-
parent, soluble in weak acids, but is precipitated from them by alkalies. It is gelatine,
nearly pure ; and if not brittle, like other glue, this depends on its fibrous and elastic
texture. The whitest and finest is preferred in commerce. Isinglass is prepand
from the air-bladders of sturgeons, and especially the great sturgeon, the AccipeHser
huso, which is fished on the shores of the Caspian Sea, and in the rivers flowing into
it, for the sake chieflv of its swimming bladder. It is also obtained from the A, std^
laius, and the A. Goldcnttadtii, We are informed that in Russia the Sihtris gloMie is
also caught for the purpose of obtaining isinglass.
The preparations of isinglass in Russia, and particularly at Astracan, consists in
steeping the swimming bladders in water, removing carefully their external coat, and
the blood which often covers them, putting them into a hempen-bag, squeezing them,
softening them between the hands, and twisting them into small cylinders. They are
ISOMOBPHISM.
605
ready for the market immediately after being dried in the san, and whitened with the
fumes of baming sulphar.
In some districts of Moldavia, another process is followed. The skin, the stomach,
the intestines, and the swimming bladder of the sturgeon are cut in small pieces,
steeped in cold water, and then gently boiled. The jelly thus obtained is spread in
thin layers to dry, when it assumes the appearance of parchment This being softened
in a little water, then rolled into cylinders, or extended into plates, constitutes an
inferior article.
The swimming bladder of the cod and many other fishes, also fUmishes a species of
isinglass, but it is much more membranous, and less soluble than that of the sturgeon.
The properties of isinglass are the same as those of gelatine or pure glue ; and its
uses are very numerous. It is employed in considerable quantities to clarify ale, wine,
liqueurs, and coffee. As an article of food to the luxurious in the preparation of
ereams and jellies, it is in great request Four parts of it convert 100 of water into
a tremulous jelly, which is employed to enrich many soups and sauces. It is used
along with gum as a dressing to give lustre to ribbons and other silk articles.
It is by covering thin silk with a coat of isinglass that court plaster is made. A
solution of isinglass covered with carmine forms an excellent injection liquor to the
anatomist M. Rochen has made another pretty application of isinglass. He
plunges into a limpid solution of it, made by means of a water-bath, sheets of wire
gauze set in window or lamp frames, which, when cold, have the appearance of glass,
and answer instead of it for shades and other purposes. If one dip be not sufficient to
make a proper transparent plate of isinglass, several may be given in succession, allow-
ing each film to harden in the interval between the dips. The onter surface should
be varnished to protect it from damp air. These panes of gelatine are now generally
used for lamps instead of horn, in the maritime arsenals of France. — See Gelatine.
Isinglass is known commercially as Ltaf isinglass, Long and short staple, and
Soak isinglass. Dr. Boyle speaks of the Samovey leaf, book, and hng and short staple,
in his paper On the Production of Isinglass along the coasts of India, with a Notice of its
Fisheries. We receive fVom the Brazils, Pipe, Lump, and Honeycomb Isinglass,
Our importations of Isinglass in 1856 and 1857, were
Coantrles from which Imported.
Russia - - -
Prussia - - -
Hanse Towns -
Philippine Islands -
Brazil ...
British East Indies -
British Guiana -
British N. America -
Other parts
Totals -
QuantUies.
1856.
CwU.
525
166
47
48
440
233
87
75
1621
1867.
Cwti.
861
21
35
365
105
51
30
25
1493
Value.
1M6.
20,598
6.509
1.838
388
6,311
1,890
1,451
1,852
£40,837
1667.
£
33,751
235
3i7
5,840
980
1,004
415
389
£42,941
ISOMERISM, from uros, eqnal, and fifpos, part Identity of elements and pro-
portions with variations in physical properties. Thus, oil of turpentine and oil of
citron are isomeric, each having the composition C'Hl The study of the laws of
atomic constitution is one of the most important within the range of physico-chemical
science, and beyond all others, it demands the highest powers of the philosopher,
united with the mechanical care of the microscopic analyst The tendency of science
leads to the conviction that many of the bodies which we now regard as distinct
elements are only isomeric ; and such groups as chlorine, iodine, bromine, and fluorine,
as sulphur, selenium, and boron, and as carbon and silicon, may with the advance of
our knowledge be shown to be modified conditions of one form of matter. This
subject will be fully treated in lire's Dictionary of Chemistry,
ISOMORPHISM. Mitscherlich was the first to observe that many eroups of sub-
stances, simple or compound, having an analogous constitution, crystallise in forms of
the same crystalline character, or differ but little in their angles. Thus, alumina,
red oxide of iron^ and oxide of chrome crystallise in forms of the rhombohedral system.
Carbonate of lime, carbonate of magnesia, protoxide of iron, protoxide of manganese,
and oxide of lime are also isomorphous forms belonging to the rhombohedral system.
606 IVORY.
Sulphate ofharyte», iu^pkaU qfstrantui, and oinde of lead orystaUise in Ifomorphie
forms of the prismatic system.
For a development of this law, consult Brooke and Miller's Mineralogy^ and Dana^s
System of Mineralogy.
IVORY. (Ivoire, Fr. ; Elfenbein, Germ.) The osseous matter of the tnska and teeth
of the elephant, and of the tusks of the hippopotamus, and the horn of the narwhaL
From a yalnable paper read by Professor Owen before the Society of Arts in
December, 1856, we extract Uie following important notices on the growth and forma-
tion of ivory: —
*' The substance of the teeth of other animals, beside the elephant, is an article of
commerce. Formerly, the name iyory was given to the main substance of the
teeth of all animals ; but it is now, by the best anatomists and physiolo^ts, restricted
to that modification at dentine, or tooth substance, which, in transverse sections or
fractures, shows lines of different colours, or stria, proceeding in the arc of a
circle, and forming by their decussation minute or curvilinear losenge-shaped spaces.
By this character, which is presented by every, the smallest portion of an elephant's
tosk in transyerse section or fhicture, true ivory may be distinguished ftx>m every
other kind of tooth substance, and Arom every counterfeit, whether derived from
tooth or bone. It is a character, — this engine-turned decussatory appearance, — which
is as characteristic of fossil as of recent ivory. Although, however, no other teeth
except those of the elephant present the characteristics of true ivory, there are teeth
in many other species of animals which, from their large size, and the density of their
principal substance, are usefbl in the arts for purposes analogous to thoae for which
true iyory is used ; and some of those dental tissues, such as those of the large tusks
of the hippopotamus, are more serviceable for certain purposes, especially in the
manufacture of artificial teeth by the dentist, than any other kind of tooth-subetance.
The utility of teeth in commerce and in the arts, depends chiefly on a peculiar modi-
fication in their laws of growth. For the most part teeth, as in our own fimmes,
having attained a certain size and shape, cease to grow. They are incapable of re-
newing ihe waste to which they are liable through daily use, and when worn avay
or affected by decay, they perish. Teeth of this kind are said to be of limited grovth ;
but there are other teeth, such as the front teeth of the rat, rabbit, and all the rodent
tribe, the tusks of the boar and hippopotamus, the long descending canine tusks of
the walrus, the still longer spiral horn-like tusk of the narwhal, and the iyory tusks
of the elephant, which are endowed with the property of perpetual growth; that is,
they grow as long as the animal lives.
** In teeth of unlimited growth, fi*esh pulp, fresh capsule, and in some instances also
fresh enamel organs are formed, and added to the pre-existing constituents of the
tooth matrix, in proportion as those are calcified or converted into tooth substance ;
and as fast as the ivory and enamel may be worn away from* the summit of such a tooth,
will ivory and enamel be formed at its base, and thus the growth of the tooth is unin-
terrupted. The ratio of the addition of the formative principles is at first greater than the
ratio of abrasion, and the tooth not only grows, but increases in size. When, how.
ever, the animal has attained its full growth, the tooth for the most part is reproduced
without increase of size, or at most, augments only in length, and that in cases vhene
its summit is not perpetually worn down by being opposed to that of an oppo«ite tooth."
With respect to the distribution of the elephant, the same high authority has the
following remarks : —
** In the present creation, elephants are restricted to the African and Asiatic con-
tinent. The African elephant, as is well known, is a distinct species from the Asiatic
one ; and some of the Asiatic elephants of the larger islands of the Indian Archipelago,
as those of Sumatra, if not specifially distinct fh)m the elephants of Continental Asia,
form, at all events, a strongly marked variety. With reference, however, to the com-
mercial relations of ivory, it is chiefly worthy of notice that in the Asiatic elephants,
tusks of a size which gives them the value of ivory in commerce, are peculiar to the
males, whilst in the African elephants, both males and females afford good-sized
tusks, although there is a sexual difference of size in this species, those of the males
being the largest In former times, and, as it would seem, before man existed to
avail himself of this beautiful animal substance for use or ornament, the large
animals furnishing true ivory-proboscidian quadrupeds, as they are termed, from their
peculiar prehensile nasal appendage, were much more widely spread over the globe
and existed in far greater numbers than in the present day, more numerous in indi-
viduals, more numerous in species, manifesting so great diversities in the confor-
mation of their grinding teeth, as to have led the naturalist and the palieontologist to
divide them into two genera, called Elephas and Mastodon, A true elephant roamed in
countless herds over the temperate and northern parts of Europe, Asia, and America.
This was the creature called by the Russians, Mammoth; it was warmly dad with
IVORY. 607
both hair and tar, as 1)ecaine an animal deriving Bostenanee from the learea and
branches of trees, which ^w as high as the 65th degree of north latitude. Some of
the ivory of commerce is, or nsed to be, derived from the tasks of this extinct
species.**
The ivor^ of the tasks of the African elephant is most esteemed by themanufactarer
for its density and whiteness.
The ontside of the tusk of the elephant is covered by the cortical part, which is
softer and less compact than the interior substance, with the exception of the brown
plate that sometimes lines the interior cavity. The hardest, toughest, whitest, and
most translucent ivory has the preference in the market; for many purposes the
horn of the. narwhal being considered the best The horn of the narwhal is some-
times ten feet long.
The ivory of the hippopotamus is preferred by dentists; it is much harder than that
of the elephant, its colour is a purer white, and it is almost tree from grain. The
teeth of the walrus, sometimes called the sea*cow, which hang perpendicularly from the
upper jaw, are also used for the same purpose. The masticating teeth of some of the
large animals are occasionally used as ivory ; those of the spermaceti whale are of a
flattened oval section, and resemble ivory in section, but they are dark coloured towards
the centre, and surrounded by an oval band of white ivory.
Ivory has been used for ornamental works from the earliest periods. Phidias is
stated to have been famous for his works made in ivory combmed with gold, and
described as the Tor&Uie Art The ivory statues of the ancients appear to have been
formed upon centres, or cores of wood covered with plates of ivory.
In our days ivory has been extensively employed by the miniature painter ; it is
used by the turner m the mannfiustare of numberless useful and ornamental articles ;
the cuUcr makes his best knife handles from it ; and the philosophical instrument
maker constructs his scales from this materiaL
When ivory shows cracks or fissures in its substance, and when a splinter broken off
has a dull aspect, it is reckoned of inferior value. Ivory is distinguishable from bone
by its peculiar semi-transparent rhombohedral net-work, which may be readily seen
in slips of ivory cut transversely.
Ivory is very apt to take a yellow-brown tint by exposure to air. It may be
whitened or bleached, by rubbing it first with poanded pumice-stone and water,
then placing it moist under a glass shade luted to the sole at the bottom, and exposing
it to sunshine. The sunbeams without the shade would be apt to occasion fissures in
the ivory. The moist rubbing and exposure may be repeated several times.
For etching ivory a ground made bv the following recipe is to be applied to the
polished surfiice:— Take of pure white wax, and transparent tears of mastic, each
one ounce ; asphalt, half an ounce. The mastic and asphalt having been separately
reduced to fine powder, and the wax being melted in an earthenware vessel over the
fire, the mastic is to be first slowly strewed in and dissolved by stirring ; and then the
asphalt in like manner. This compound is to be poured out into lukewarm water, well
kneaded, as it cools, by the hand, into rolls or balls about one inch in diameter. These
should be kept wrapped round with taffety. If white resin be substituted for the
mastic, a cheaper composition will be obtained, which answers nearly as well ; 8 oz.
asphalt, 1 oz. resin, \ oz. white wax, being good propor^ons. Callofs etching ground
is made by dissolving with heat 4 oz. of mastic in 4 oz. of very fine linseed oil ; filter-
ing the varnish through a rag, and bottling it for use.
Either of these grounds being applied to the ivory, the figured design is to
be traced through it in the nsusd way, a ledge of wax is to be applied, and the
surfiuse b to be then covered with strong sulphuric acid. The effect comes better out
with the aid of a little heat ; and by replacing^ the acid, as it becomes dilute by ab-
sorption of moisture, with concentrated oil of vitriol. Simple wax may be employed
i' sead of the copperplate engravers' ground; and strong muriatic acid instead of
sulphuric If an acid solution of silver or gold be used for etching, the design will
become purple or black on exposure to sunshine. The wax may be washed away with
oil of turpentine. Acid nitrate of silver affords the easiest means of tracing permanent
black lines upon ivory.
Ivory may be dyed by using the following prescriptions : «•
1. Black dye, — If the ivory be laid for several hours in a dilute solution of neutral
nitrate of pure silver, with access of light, it will assume a black colour, having a
slightly green cast A still finer and deeper black may be obtained by boiling the
ivory for some time in a strained decoction of logwood, and then steeping it in a solution
of red sulphate or red acetate of iron.
2. Blue Jjv.— When ivory is kept immersed for a longer or shorter time in a dilute
solution of sulphate of indigo (partly saturated with potash), it assumes a bine tint of
greater or less intensity.
608 IVORY.
3. Green dye, — This is given by dipping bloed ivory for a little while in solatton of
nitro-mariate of tin, and then in a hot decoction of fustic.
4. YeUow dye — is given by impregnating the ivory first with the abore tin mordant,
and then digesting it with heat in a strained decoction of fustic. The colour passes
into orange, if some Brazil wood has been mixed with the fustic. A very fine un*
changeable yellow may be communicat(td to ivory by steeping it 18 or 24 hours in a
strong solution of the neutral chromate of potash, and then plunging it for some time
in a boiling hot solution of acetate of lead.
5. Red aye — may be given by imbuing the ivory first with the tin mordant, then
plunging it in a bath of Brazil wood, cochineal, or a mixture of the two. Lac-dye may
be used with still more advantage, to produce a scarlet tint If the scarlet ivory be
plunged for a little in a solution of potash, it will become cherry red.
6. Videt dye — is given in the logwood bath, to ivory previously mordanted for a
short time with solution of tin. When the bath becomes exhausted, it imparts a lilac
hue. Violet ivory is changed to purple-red by steeping it a little while in water con-
taining a few drops of nitro-muriatic acid.
With regard to dyeing ivory, it may in general be observed, that the colours penetrate
better before the surface is polished than afterwards. Should any dark spots app«far,
they may be cleared up by rubbing them with chalk ; after which the ivory should be
dyed once more to produce perfect uniformity of shade. On taking it out of the boiling
hot dye bath, it ought to be immediately plunged into cold water, to prevent the chance
of fissures being caused by the heat
If the borings and chips of the ivory-turner, called ivory dust, be boiled in water,
a kind of fine size is obtained.
ItMry nutde flexible. — Ivory articles may be made flexible and semi-transparent, by
immersing them in a solution of pure phosphoric acid of sp. gr. 1*130, and leaving them
there till they lose their opacity ; they are then to be taken out, washed with water,
and dried with a soft cloth ; it thus becomes as flexible as leather. It hardens on
exposure to dry air, but resumes its pliancy when immersed in hot water. Necks of
children's sucking bottles are thus made.
It is not our intention to enter into the consideration of the handicrafts employing
ivory, but a short account of the methods of preparing this beautiful material, which
we extract from Hollzapffel*s Mechanical Manipulation, will be of value.
"On accotmt ofthe great value of ivory, it requires considerable judgment to be
employed in its preparation, from three conditions observable in the torm of the tusk ;
first, its being curved in the direction of its length ; secondly, hollow for about half
that extent, and gradually taper from the solid state to the thin feather edge at the
root ; and thirdly, elliptical or irregular in section. These three peculiarities give
rise to as many separate considerations in cutting up the tooth with the requisite
economy, as the only waste should be that arising from the passage ofthe thin blade of
the saw : even the outside strips of the rind, called spills, are employed for the handles
of penknives, and many other little objects ; the scraps are burned in retorts for the
manufacture of ivory black, employed for making ink for copper plate printers, and
other uses, and the clean sawdust and shavings are sometimes used for making jelly.
" The methods of dividing the tooth, either into rectangular pieces or those of a
circular figure required for turning, are alike in their early stages, until the lathe is
resorted to. The ivory saw is stretched in a steel frame to keep it very tense ; the
blade generally measures from fifteen to thirty inches long, from one and a half to
three inches wide, and about the fortieth of an inch thick ; the teeth are rather
coarse, namely, about five or six to the inch, and they are sloped a little forward, that
is, between the angle of the common hand-saw tooth and the cross-cut saw. The
instrument should be very sharp, and but slightly set ; it requires to be guided very
correctly in entering, and with no more pressure than the weight of its own frame,
and is commonly lubricated with a little lard, tallow, or other solid fat
*' The cutter begins generally at the hollow, and having fixed that extremity parallel
with the vice, with the curvature upwards, he saws off that piece which is too thin for
his purpose, and then two or three parallel pieces to the lengths of some particular
works, for which the thickness ofthe tooth at that part is the most suitable ; he will then
saw off one very wedge-form piece, and afterwards two or three more parallel blocks.
*' In setting out the length of every section, he is guided by the gradually increasing
thickness of the tooth ; having before him the patterns or images of his various
works, he will in all cases employ the hollow for the thickest work it will make. As
the tooth approaches the solid form, the consideration upon this score gradually ceases,
and tiien the blocks are cut off to any required measure, with only a general reference to
the distribution of the heel, or the excess arising from the curved nature of the tooth,
the cuts being in general directed as nearly as may be to the imaginary centre of cur-
vature. The greater waste occurs in cutting up very long pieces, owing to the differ*
JACQUARD.
609
e»ce between the stnught line and the curve of the tooth»on which account the blocks
are rarely cut more than five or six inches long, anless for some specific object."
Mr. P. Ia Sinunondfl has given the following as the weights of large elephants'
tasks: —
Mr, Gordon Camming had one weighing -----
Mr. Cawood, of Graham's Town, had a pair weighing
From Camaroon, shipped to Liyerpool - . - . .
A tnsk imported at Bristol .......
At the Great Ezhibiticm of 1851, task
173 lbs.
830 lbs.
164 lbs.
147 lbs.
162 lbs.
ImportM of Ivory in thB Years 1856 and 1857.
TxETH— Elephants, sea cow, sea horse,
or sea morse : —
Portugal . - - - .
Tuscany - - . . .
Egypt
West €k)ast of Africa - - .
United States . . . .
Malta
Sierra Leone . . . .
Gold Coast . . . .
South Africa . . . .
British East Indies - - -
Other parts - - - -
Total
Quantities.
18S6.
CwU.
811
153
828
1023
246
838
89
91
579
6027
181
1897.
Cwta.
496
151
1728
1132
644
458
133
1192
3349
529
9866
9890
Value.
18S6.
28,609
5,431
29,532
36,382
5,594
29,889
3,174
8,246
20,572
176,117
4,971
343,517
1857.
21,149
6,478
74,085
48,527
26,424
19,648
5,706
51,090
142,575
22,290
421,318
IVORY BLACK (Noir cTivoire, Fr. ; Kohle von El/enbein, Germ.) is prepared from
ivory dust, by calcination, in the very same way as is described under Bone Bulck.
The calcined matter being g^round and leyigated on a porphyry slab affords a beautiful
velTety black, much used in copperplate printing.
1 VOBY, FICTILE, is plaster of Paris which has been made to absorb, after drying,
melted spermaceti, by capillary action, or it may be prepared according to Mr.
Franchi's process as follows : — Plaster and colouring matter are employed in the
proportions of a pound of superfine plaster of Paris to half an ounce of Italian yellow
ochre. They are intimately mixed by passing them through a fine silk sieye, and a
plaster cast is made in the usual way. It is first allowed to dry in the open air,
and is then carefully heated in an oven ; the plaster cast, when thoroughly dry is
soaked for a quarter of an hour in a bath containing equal parts of white wax, sper-
maceti, and stearine, heated just a little beyond the melting point The cast on remoyal
is set on edge, that the superfluous composition may drain ofl^ and before it cools,
the surface is brushed, with a brush like that known by house painters as a sash tool,
to remove any wax which may have settled in the crevices ; and finally when the
plaster is quite cold, its surface is polished by rubbing it with a tuft of cotton wooL
IVORY NUT. Corosos, or vegetable ivory. A species of the screw pine Paniiantfff
growing in Central America and Columbia. The Phyidephas macrocarpa produces
these nuts, which have a structure somewhat resembling that of ivory ; but it more
nearly resembles white wax. The ivory nut is not used for any important work.
J.
JACK, called also jacA in a box, and hand-jack, is a portable, mechanical instrament,
consisting of a rack and pinion, or a pair of claws and ratchet bar, moved by a winch
handle, for raising heavy weights a little way ofif the ground.
JACK and JACK-SINKERS, are parts of a stocking frame. See Hosiery.
JACK-BACK, is the largest jack of the brewer.
JACK, BLACK. The miners' name for the sulphide (sulphuret) of sine, or blende.
See Znro.
JACQUARD. A peculiar and most ingenious mechanism, iiivented by M. Jac-
Vox. IL R R
JACQUABD.
pboald rite ■imnlUnnniilj to produce the figure, have Iheir tppropriate bealdi, which
a child fbmirrlj railed by meuis of cord*, thiit grouped ihem together into a ■ jtmn, in
the order, aud at the time deiired by the ireaTer. This plan erideDtly occaiiotied do
JACQUARD.
regnlv mcchaniciil operation, and
deriTMit*mMMDft«inA«imple|iedalput in tctioo by dia wmtct'i feet, -wia genuvlly
adopted Mon ifler iu invontioa in ISOIX Ejery coinittMi loMn it iiuceptiUe of re-
ceiving lliii iKmatiftil appsndigck It eoft* in France 300 tnact or SL Herling, and k
litUe mate in tbii oonntrj.
Fii). i(Ma i« » front elevation of thi«in«chiniwn,«nppo»«dtobal«tdowB. Fig.ioa
it B eroee section, thovn in iti hi^ieit poiition. Fig. 1047, tlie fame wetios m tlie
preMding, but lean in ill lower potition.
A, is the fixed part of ttie frame, mppoeedlofiiTniapartof theotdiDary loom; there
are two npriglit* of irood, vitb two croai-ban nnilins tliem at tbeir upper ends, and
leaving an iDterral zjibeCWeeDtliem, to place and woik the rooTable frame b, Tibrating
rooDd two fised pointi a a, placed LateraU; oppcait* eacb other, in tite middle of the
ipac« X y, _fig. 104S.
c ii a piece of iron with a peculiar CDTTature, Ken in front fig- 104S, and in profile,
figt. 104S and 1047. It ii fliedon one side upon the upper croas-bar of the fi^me b,
and on the other, to the intermediate crosa-bar b of the aame fhune, where il (bow*
an inclined carTiiinear ipace c, terminated below by a semicircle.
D ii a aqnare wooden aiii, movable upon itself ronad two iron pivota, fixed into it*
two ends ; which aiii occapiea the bottom of the movable frame a, Tbe four facea of
Ibis sqoare azia are pierced with three round, equal, truly-bored holea arraoged in
B qnincanz. Tbe te«th a, fig. 1019, are ttock into each face, and correapood to
boles a, fig. ]033, made in the cardi which eonatilate iheendleta chain for the heajdai
■o thai Id the aucceaiive application of the cards to eacb &ce of the square axia,
tb« holes pierced in one card may always fall opposite to those pierced in the other.
Tike righl-hand eiid of the square axis, of which a section is shown in double «ie,
fig. I04B, carries two iqnare plates of sheet iron d, Itept parallel to each other and
a little apart, b; four spindles e, passed opposite to the comera. This is a kind of
■ ia a piece of wood shaped like a T, the stem of which, prolonged upwards, pane*
freely through the croaa-bu'&, and through thenpper cross-bar of the frame a, which
lerre as guidea to iL The head of the T piece being spplied sucCMsively aoainat
the two spindles a, plae«d above in horiiontal position, first by its weight, and then
bj the spiral spring A, acting tmm above downwards, keeps the square axia in its
poeiiion, while it perinita it to turn upon itself in tbe two directions. The name proM
is given to the aiaemblage of all the pieces which eompose the movable ttwne B B.
T it a cross-bar made to move in a vertical direction by meins of the lever a, in the
notches or grooves ■', formed within tbe fixed nprlgbfi A.
H i« a piece of bent iron, fixed by one of its ends with a nut and kt«w, upon the
erosa-bar r, oat of the vertical pUne of the piece c Its other end carries a friction
roller jr, which, working in the curvilinear apace e of the piece c, forces this, and
oonteqnently the frame b, to recede fVom the perpendicular, or to retnm to it, ac-
cording M the CTcat-bar i It in the top or bottom of iU eonrse, at shown in J^s.104fl
•nd 1047.
J, cheekt of ihe«t iron attached on either side to the crost-bar f, which serve at » safe
to a kind of claw X, composed here of eight smallinelallie hart, teen in section^^ 1046
and 1047, and on a greater icale in^. L04S.
J, npri^t skewers of iron wire, whose tops bent down hookwiee natnrally place
thenuclvea over the little bars x.' The bottom of these spindles likewise booked in
the same direction as the npper ones, embraces small wooden bars I, whose o" —
612 JACQUARD.
npoD wlueh tlwy impend. To IheM hook* from Mow me altBched »t^iogi^ whieb
arter having croned a fi<ed board n ■, pierced wiih coTretpoDdiDB holes for thii
pnrpow, proceed neat to be aiUcbed (o the thread* of the loopa dettined to lift the
warp threadi. K «, horiaontal spindlei or needles, arranged here in eight ■everal
rows, so that each (pindle correapondj both horiioDtallT and vertieall; to each of tbc
holes pierced in the four feces of the sqnare axis d. There are therefore as manj d
thcM spindles as there are boles in one of the &cea of the square.
Fb. 1050 representa one of these hariiontal spindles, n is an eyelet tbrongfa which
the correapooding Tertieal skewer passea. o another elongated eyelet, through which
a amall fla«d spudle passes to serve as a guide, but which doe* not hinder it frotn
moving lengthwise, within the limiu of the length of the eyelet p, small spiral
«priDgB placed in each hole of the case q q,fig. 1049. They serve the purpoKof
bringing back to iti primitive pontion every correspooding needle as soon as it
ceases to pr«ss npon it
IDGO
IfiWHNHft^ =^ -■ 3.
F^. 1051 representa the^anoftbeapperrowofboriaontal needle*. Fig.lOSiiMt
fragment of the endless chain, formed with jierfbrnted cards, which are made to cir-
culate or travel by the relation of the shaft D. In this movement, each of the perfo-
rated cards, whMe position, form, and number, are determined by the operation of
tying-up of the warp, comes to be applied in succcssioa against the fonr faces of the
square axis or dnup, leavlna; open tbc correaponding holes, and covering those upon
the fhce of the aiia which have no correBponding boles npon the card.
Now let us suppose that the prcMi n is let down ioto the vertical position shown in
Jig. 1047 ; then the card applied igaingl the left face of the axis, leaves at rest or
untouched the whole of the horizontal spindles (skewers), whose ends correapond lo
these holes, bnt poshes back those wtiich are opposite to the impierced put tyS the
cardj thereby the corresponding npright skewers, 3, 5, 6, and S, for example, pushed
out of the perpendicnlar, onhook themselves from above the ban of the claw, and
remain in their place, when this claw comes to be r^sed by means of the lever o ; and
the skewers 1, 2, 4, and T, which have remained hooked on, are raised along with the
warp threads attached to them. Then by the passage across of a shot of die cokor,
as well as a shot of the common weft, and a stroke of the lay after shedding the warp
and lowering the press n. an element or point in the pattern is completed.
The fallowing card, brought round hv a qnarter revolution of the ai ' ' ' ~ '
needlei In their first poution, and ai it is necessarily perforated difierenlly flmn the
nreceding card, It wiL lift another series of warp threads ; and thus in sncceninn far
! other card*, which compose a complete mten of a figured pattern.
This nuiGhine, complicated in appearance, and which requires some pains to be nn-
derstood, acts however in a very «imple manner. Its whole play is dependent npon the
movement of the lever a, which the weaver himself causes lo rise and fall, by mean*
of a pecoliar pedal ; to that without the aid of any person, after the piece ia properly
read in and mounted, he can execute the most complex patterns as easily aa he could
weave plain goods ; only attending to the order of hi* weft yama, when these hsfipai
to be of different colours.
If some warp yarns shonld happen to break without the weaver obaerring than, or
should he mistake his coloured buttle yama, which would lO fM disGgnre the paU«ni.
be must undo his work. For this purpose, he makesnse of the lower hooked Xrrttf,
whose purpose is to make the chain of (he card go backwards, while working the loon
as usual, withdrawing at each etroke the shot bath of the ground and of the figure.
The weaver is the more subject to moke mistakes, as the figured side of the web i*
downward*, and it ia only with the aid of a hit of looking-glas* that he take* a peep of
hi* work from time to time. The upper surface exhibits merely loose thread* in dif-
JACQUABD.
618
fcrent points, according as the pattern requires them to lie upon the one 'side or the
other.
Thos it mnst be evident, that such a number of paste-boards are to be provided and
mounted as equal the number of throws of the shuttle between the beginning and end
of any figure or design which is to be woven ; the piercing of each paste-board indi-
vidually will depend upon the arrangement of the lifting rods, and their connection
wiUi the warp, which is according to the design and option of the workman ; great
care must be taken that the holes come exactly opposite to the ends of the needles ;
for this purpose two large holes are made at the ends of the paste-boards, which fall
upon conicid points, by which means they are made to register correctly.
It will be hence seen, that, according to the length of the figure, so must be the
number of paste-boards, which may be readily displaced so as to remount and produce
the figure in a few minutes, or remove it, or replace it, or preserve the figure for future
use. The machine, of course, will be understood to consist of many sets of the lifting
rods and needles, shown in the diagram, as will be perceived by observing the dispo-
aition of the holes in the paste-board ; those holes, in order that they may be accu*
rately distributed, are to be pierced from a gauge, so that not Uie slightest variation
shall take place.
To form these card-slips, an ingenious apparatus is employed, by which the proper
steel punches required for the piercing of each distinct card, are placed in their relative
situations preparatory to the operation of piercing, and also b^ its means a card may
be punched with any number of holes at one operation. This disposition of the punches
is effected by means of rods connected to cords disposed in a frame, in the nature of
a false simple, on which the pattern of the work to be performed is first read in.
These improved pierced cards, slips, or paste-boards, apply to a weaving apparatus,
which is so arranged that a figure to be wrought can be extended to any distance along
the loom, and by that means the loom is rendered capable of producing broad figured
works ; having the long lever o placed in such a situation that it affords power to the
foot of the weaver, and by this means enables him to draw the heaviest morintures
and figured works, without the assistance of a draw-boy.
The machinery for arranging the punches consists of a tnaae with four upright
standards and cross-pieces, which contains a series of endless cords passing under a
wooden roUer at bottom, and over pulleys at the top. These pulleys are mounted on
axles in two frames, placed obliquely over the top of the standard frame, which pulley-
frames constitute the table commonly used by weavers.
In order better to explain these endless cords. Jig, 1053 represents a single endless
cord, 1 1, which is here shown in operation, and part of another endless cord, 2 2,
shown stationary. There must be as many endless
cords in this frame as needles in the weaving-loom.
a is the wooden cylinder, revolving upon its axis at
the lower part of the standards: b b, the two pulleys
of the pulley-frames above, over which the indivi-
dual exidless cord passes ; c is a small transverse ring.
To each of these rings a - weight is suspended by
a single thread, for the purpose of giving tension to
the endless cord. J is a board resembling a common
eomber-bar, which is supported by the cross-bars of
the standard frame, and is pierced with holes, in situa-
tion and number corresponding with the perpendicu-
lar threads that pass through them ; which board ^ ^
keeps the threads distinct from each other.
At «, the endless cord passes through the eyes of
wires resembling needles, which are contained in a
wooden box placed in front of the machine, and shown
in this figure in section only. These wires are called
the puncM'prqjeetors ; they are guided and supported
by horizontal rods and vertical pins, the latter of
which pass through loops formed at the hinder part
of the respective wires. At /are two horizontal rods
extending the whole width of the machine, for the
purpose cf producing the cross in the cords ; ^ is a
thick brass plate, extending along in front of the ma-
chine, and lying close to the box which holds the
pttnch-prqjectort ; this plate g, shown also in section,
is called the punck^holder ; it contains the same number of apertures as there are
punch-projectors, and disposed so as to correspond with each oUier. In each of these
apeitares, there is a punch for the purpose of piercing the cards, slips, or pasteboards
B B 3
1053
614 JAPANNING.
with holes ; A is a ^tMi vteel plate of the same siae as g, and shown likewise iniedios,
corresponding also in its number of apertares, and their disposition, with the punch-
projectors and the pnnch-holder. This plate A, is called the jnmdi-receioer.
The object of this machine is to transfer such of the panehes as nkay be leqaindftr
piercing any individoal card from the ponch^holder g, into the ponch-reoetver A ; vhea
they will be properly situated, and ready for piercing the individoal earl or slip with
such holes as have been read in upon the machine, and are required for permittmgthe
warp threads to be withdrawn in the loom, when this card is brought against the eads
of the needles. Hie process of transferring the patterns to the punches will be effected
in the following manner.
The pattern is to be read in, according to the ordinary mode, as m a fake simple,
upon the endless cords below the rods fi and passed under the revolviog voodea
cylinder a, to a sufficient height for a person in front of the machine to reach eoDTe-
niently. He there takes the upper threads of the pattern, called the beard, and drtn
tbem forward so as to introduce a stick behind the cords thus advanced, as shova by
dots, for the purpose of keeping them separate from the cords which are not intended to
be operated upon. All the punch-projectors which are ooqneeted with the ooida broDgbt
forward will be thus made to pass through the corresponding apertares of the ponch-
holder ^, and by this means will project the punches out of these apotores, into cor-
responding apertures of the punch-receiver k, The punches will now be properlj
arranged for piercing the required holes on a card or slip, which is to be effected is
the following manner.
Remove the punch-receivers firom the firont of the machine ; and having pboed ooe
of the slips of card or pasteboard between the two folding plates of metal, completely
pierced with holes corresponding to the needles of the loom, lay the poneh-rMeirer
upon those perforated plates ; to which it must be made to fit by mortises and blocks,
the cutting parts of the punches being downwards. Upon the back of die psneh-
receiver is then to be placed a plate or block, studded with perpendicular pinS) corre-
sponding to the above described holes, into which the pins will falL The plates sod
the blocks thus laid together, are to be placed under a press^ by which mesas the pba
of the blocks will be miBde to pass through the apertures of the puncb-receirer; tod
wherever the punch has been deposited in the receiver by the above proeess, the slid
punches will be forced through the slip of pasteboard, and pierced with rach holes is
are required for producing the figured design in the loom.
Each card being thus pierced, the punch-receiver is retamed to its place is front of
the machine, and all the punches forced back again into the apertares of the punch*
holder as at first. The next set of cords is now drawn forward by the next bearit
as above described, which sends out the punoh'prqjeciora as before, and disposes the
punches in the punch-receiver, ready for the operation of piercing the next card. The
process being thus repeated, the whole pattern is, by a number of operatioas» tnnsferRd
to the punches, and afterwards to the cards or slips, as above described.
JADE, axe-stone (Nephrite, Cerauniie, Fr.; BeiUlein^ Germ.), is a mineral of a
greenish, bluish, or whitish colour, compact, and of a fktty lustre. Spec. graT.S'95;
scratches glass ; is very tough ; fuses into a white enamel. It comes from China, and
has been found in Australia ; it is used among rude nations for miJcing hatchets; lad
is susceptible of being cut into any form. In China the jade is greatly valued, cspe-
cialiy the pure white varieties. These are worked into cups, and as oroaments for
the Joo-e, or emblem of power.
The composition of jade, as given by Kastner and Raunoelaberg, is —
Silica 50*50 - - bAHS
Magnesia ..... 31*00 - - 26*01
Lime ---...-•- 16*06
Protoxide of iron -.-..-- 2*15
Peroxide of iron ... - S'So
Alumina ..... lO'OO
Chromium .... o*05 H. W. B.
JAPAN EARTH ; Terra Japanica, See Gambir.
JAPANNING is a kind of varnishing or lacquering, practised with excdlenoe by
the Japanese, whence the name.
The only difference between varnishing and japanning is that after the applieatkn
of every coat of colour or varnish, the object so varnished la placed in sn oven or
stove at as high a temperature as can safely be employed without injuring the articles
or causing the varnish to blister or run.
For black japanned works, the ground is first prepared with a coating of black, made
by mixing dross ivory black to a proper consistence with dark ooknired sa>»
varnish, as this gives a blacker surfiice thaa could be produced by japan alooe. 1'
JET. 615
the ■nrftoe U required to be polished, live or eix eoate of jftpan are neceMurj to giye
BoiBeient body to prevent the japan firom being mbbed through in poliahing.
Coloured Japana are made hj mixing with tome hard yamiahea the required colour,
and prooeedinff aa described. See VARNiaa.
JARGOON, the name given to a yarietj of Zircon from Ceylon. It is seldom
perfectly transparent, and is either colourlen or grey, with tinges of green, blue, red,
and yellow of yarioos shades, but generally smoky and ill-defined. It occurs in worn
angular pieces, or in small detach^ crystals, rarely exceeding 6 or 8 carats in weight,
chiefly in the sand of a riyer in Ceylon. The surftioes of the crystals are smooth, and
poisesa a Instre more nearly approaching that of the diamond than any other gem.
At the present day, though oat of ftahion and in no request, it is still occasionally
sold for inferior diamonds.
Dayy says that the li^ht grey yarietiea of the sircon are sold by the inhabitants of
Ceylon as imperfect diamonds, the natiyes being alto^ther ignorant of the true
nature of the mineral. It is most abundant in the district of Matura, whence it has
its common name in Ceylon of Mattara diamomd. The colourless siroon is also cut
and Bold as a fidse diamond in the baaaars of India. — H. W. B.
JASPER (Jaape ealeedoime, Fr.; JasptM, Germ.) is a sub-species of quartz, of which
there are five yarietiea. 1. The Egyptian red and brown, forming nodules with
ring or tendril-shaped delineations. 2. Striped jasper, or clay altered by heat, and
differing from true jasper by being ftisible on the edges, before the blowpipe. 8.
Poreelam riband or jasper. 4. Common jasper. 5. Agate jasper. The prettiest
specimens are cut for seala, and for the inferior kinds of jewellery omamenta. See
LAFiDAar. — H. W. B.
J ATROPH A MANIHOT. A plant belonging to the EophorbiaoesB, from which
the Castaoa meal is prepared, and firom the express juice of which is obtained CcMova
starch and Tapioca. See Tapioca.
JEAN. A twilled cotton, usually striped. Satin-jeans are woven so as to present
a smooth glossy appearance. It is used for stays, &c
JELLl^ ANIMAL. See Gklatzhb, Glitk, and IsnroLAfla.
JELLT, VEGETABLE. A great many vegetable productions yield upon inftision
or decoction gelatinous solutions. These vary very much in character. The jelly of
ripe enrrants and other berries, is a comj^und of mucilage and acid, which loses its
power of gelatinising by prolonged ebullition.
JESSAMINE or JASMINE. A well-known fkmily of plants. The Jamium
fruHcamM, a native of the southern parts of France, J. odbraeuMnnaR, a native of India,
and J. ntmbae^ a native of India and Arabia, are used to obtain the essential oil of
jasmine. See PsBrnMBRT.
JET. {Jaiett or jais^ Fr.) Jet occurs in the upper lias shale in the neighbourhood
of Whitby, in Yorkshire, in which locality this very beautiful substance has been
worked for many hundred years. The jet miner searches with great care the slaty
rocks, and finding the jet spread out, often in extreme thinness between the lamina-
tiona of the rock, he follows it with great care, and frequently he is rewarded by its
thickening out to two or three inches.
The best jet is obtained from a lower bed of the upper lias formations. This bed
baa an ayerage thickness of about SO feet, and is known as jet rock. An inferior
kind, known as soft jet, is obtained ftvm the upper part of the upper lias, and from the
sandstone and shale above it The production of jet in this country appears to be
limited to the coast of Yorkshire, fivm about nine milea souUi of Whitby to Boulby,
about the same distance to the north ; the estates of Lord Mulgrave being especially
productive. There is a curious allusion to this in Drayton's Polyolbion.
The rodif by MoultgraTe, too, mr glories forth to let.
Oat of their cranoiea roelu can give jou perfect jet.
Dr. Young, in his Geology of the Yorkshire Coast, writes — ''Jet, which occurs here in
considerable quantities in the aluminous bed, may be properly classed with fbssil wood,
aa it appeart to be wood in a high elate o/ Intumenieation. Pieces of wood impregnated
with silez are often found completely crusted with a coat of jet about an inch thick.
But the most common form in which the jet occurs is in compact masses of from
half an inch to two inches thick, frx>m three to eighteen inches broad, and of ten or
twelve feet long. The outer surface is always marked with longito<Unal striie, like
the grab of woDd, and the transverse fracture, which is conchoidal, and has a resinous
lustre, displays the annual growth in compressed elliptical zones. Many have
supposed this substance to be indurated petroleum, or anmuUpiteh\ but the fhcts now
quoted are sufficient to prove its ligneous origin."
It does not appear to us that the ** ligneous origin ** of jet is by any means established ;
indeed we think the amount of evidence is against it There is no example as far as we
oan learn, of any discovery of true jet having a strictly ligneous stmoture, or showing
R R 4
616 JET.
anything like the eonyersibn of wood into this coel-like snhrtaooe. There appesrv,
however, to have heen some confusion in the ohservations of those who have wiittcB
on the subject. Mr. Simpson, the intelligent curator of the MThithy moseiuo, who
has paid much attention to the subject, says, " Jet is generally considered to have
been wood, and in many cases it undoubtedly has been so $ for the woodj stractnre
often remains, and it is not unlikely that comminuted vegetable matter may have
been changed into jet But it is evident that vegetable matter is not an essential
part of jet, for we frequently find that bone, and the scales of fishes also have been
changed into jet In the Whitby Museum there is a large mass of bone, which has
the exterior converted into jet for about a quarter of an inch in thickness. The
jetty matter appears to have first entered the pores of the bcme, and there to have
hardened ; and during the mineralising process, the whole bony matter has been
gradually displaced, and its place occnpied by jet, so as to preserve its original form.**
After an attentive examination of this specimen, we are not disposed to agree
entirely with Mr. Simpson.
Jet certainly incrusts a mass which has something the structure of a bone, hot,
without a chemical examination of its constituents, we should hesitate even to say it was
bone. Wood without doubt has been found encrusted with jet, as fragments of animal
matter may also have been. But it is quite inconsistent with our knowledge of phjrsieal
and chemical changes, to suppose that both animal and vegetable matter would nndog*
this change. By process of substitution, we know that silica will take the place occapied
by carbon, or woody matter ; as, for example, in the fossil palms of Trinidad, and the
silicified forests of £gypt ; but we have no example withm the entire range of the
coal formations of the world of carbon taking the place of any of the eartha.
Jet is found in plates, which are sometimes penetrated by belemnites. Mr. Ripley, of
Whitby, has several curious examples, — two plates of jet, in one case enclose water-
worn quartz pebbles ; and in another jet partially invests an angular fragment of
quartz rock. ** This is the more remarkable," says Mr. Simpson, ^as quartz rock, or,
indeed, any other sort of rocky fragment is rarely found in the upper Has.**
The very fact that we find jet surrounding belemnites, easing adventitioos masses
of stone, and investing wood, seems to show, that a liquid, or at all events, a plasdc
condition, must at one time have prevailed. We have existing evidence of this. Dr.
Young, in the work already quoted, says : — ** In the cavities of nodules containing
petrifactions, we sometimes meet with peiroieum, or minercU oil Wh«i first exposed,
it is generally quite fluid and of a dark green colour ; but it soon becomes viscid and
black, and at last hardens into a kind of pitch, which generally melts with heat and
when ignited bums with a crackling noise, and emits a strong bituminous smell.**
One more sample of evidence in favour of the view that jet has been formed front
wood. It is stated {Reed's Illustrated Guide to WkUby) that in front of the cliff-
work of Haibume Wyke existed a petrified stump of a tree, in an erect postvrc, thre«
feet high, and fifteen inches across, having the roots of coaly jet in a bed of shale ;
whilst the trunk in the sandstone was partly petrified, and partly of decayed sooty
wood. Even in this example it would appear, that after all, a coating of jet was all
that really existed upon this example of the equisetum, which probably stands where
it grew. Mr. Simpson, in a valuable little publication, ** The Fossils of the Yorkshire
lAas described from Nature, with a short OuUine of the Geology of the Yorkshire Coasts
says : — ** From all we know respecting this beautiful mineral, it appears exceedingly
probable that it has its origin in a certain bituminous matter, or petroleum, which
abundantly impregnates the jet-rock ; giving out a strong odour when it is exposed
to the air. It is frequentlv found in a liquid state in the chambers of ammonites and
belemnites and other cavities, and, whilst the unsuspicious operator is breaking a lias
nodule, it flies out and stains his garment This petroleum, or mineral oil, also
occurs in nodules which contain no organic remains ; and I have been informed by
an experienced jet miner that such nodules are often associated with a good seam of
jet, and are therefore regarded as an omen of success."
Jet is supposed to have been worked in this country long before the time of the
Banes in England, for the Romans certainly used jet for ornamental purposes. Lionel
Charlton, in the history of Whitby, says, that he found the ear-ring of a lady having the
form of a heart with a hole in the upper end for suspension from the ear, it was foond
in one of the Roman tumuli, lying close to the jaw bone. There exists no doubt that
when the abbey of Whitby was the seat of learning and the resort of pilgrims, jet
rosaries and crosses were common. The manufisM^ture was carried on tiU the time of
Elizabeth, when it seems to have ceased suddenly, and was not resumed till the year
1800, when Robert Jefferson, a painter, and John Carter made beads and crosses with
files and knives: — ^a neck guard, made in this manner, fetched one guinea. A stranger
coming to Whitby saw them working in this rude way, and advised them to try to torn
it ; they fi»llowed his advice and found it answer ; several more then joined thenit sod
KATTIMUNDOO. 617
the trade has been gradnally increaaing since. Moat of the beat Jet ornamenta arc
aent to London, the inferior ones are mostly purcbaaed for the American market
The jet workera complain 4>f the great acarcity of designs in jet Several designs
have been sent them, but the artists not being acquainted with the peculiarities of the
material, their designs are not generally applicable, and the mannfiusturer is much
more successful in the imitation of natural objects than any artificial combination.
JEWELLERY. See Gem and Lafidabt.
JIGGING, a mining term. Separating the ore with a griddle, or wire-bottomed
sicTe, the heayier substances passing through to the bottom or lower part of the
sieve, the lighter substance remaining on the upper part
J I NT A WAN. A substance somewhat resembling caoutchouc, imported fh>m India.
JUJUBE. The fruit of the lAzyphua mdgarit and L.Jttjuba, about the sixe of and
nearly resembling a small plum. The French confectioners prepare a lozenge from
the juice of the fruit, but nearly all the Jt^ubes sold by our druggists and confectioners
are merely dried mucilage, flavoured and sweetened.
JUMPER, a mining term, A large borer» steeled at each end like chisel bits. It is
worked by the hand.
JUNIPER. A genus of plants belonging to the order Conifenu About twenty
species are known. Thia plant is cultivated mostly for its berries, which, when dis-
tilled with water, yield a volatile essential oil. The berries are largely employed in
the mannflM:ture of Hollands and gin. The French name of ^e plant is Genevre, and
hence our Engliah words ** gin " and ** geneva."
The Junipenu BermutUanOj the Bermuda red cedar, is a large tree with soft and fra^
grant wood, and is what is used in making pencils, and by cabinet makers. See Cedar
JUTE consists of the fibres of two plants, called the chonch and isbund (Corckonu
oUtorivM and Corchorue capsuiaris), extensively cultivated in Bengal, and forming, in
fiftct, the material of which gunny bags and gunny cloth are made. It fetches nearly,
though not quite so hi^^h, a price as sunn. See Sunn. It comes into competition
with fiax, tow, and codilla, in the manufacture of stair and other carpets, bagging for
cotton and other goods, and such like fabrics, being extensively used for these pur-
poses in Dundee. But it is unsuitable for cordage or other articles into which hemp
is mannfiictored, firom its snapping when twisted, and rotting in water. — JlPCtdtoch,
K.
KABOOK* A name for a clay Ironstone in Ceylon. — Simmonds.
K AL. ** Wild iron ; a coarse, false kind of iron ** (^Uorkue), A mining term. In
St. Just, in Cornwall, a eaUan lode is a lode containing much iron.
KALEIDOPHON. An instrument devised bv Prof. Wheatstone. An elastic thin
bar is fixed by one of its extremities, and at its free end it carries a silvered or
polished ball ; a ray of light is reflected from this ball, and when the thin plate is put
in vibration, the fine point of light describes various curves, corresponding with the
musical notes produced by the vibrations.
KALEIDOSCOPE. A well-known instrument invented by Sir David Brewster.
It has been much employed in arts of design. The leading conditions are that the
angle at which the reflectors are placed is a submultiple of 360^, that the only positions
in which a body can be placed to form perfectly symmetrical images are between the
ends of the mirrors, or in contact with the ends, and the eye must be as near as pos-
sible to the angular point
KALL The Arabs gave this name to an annual plant which g^ws near the sea-
shore ; now known under the name of aaUoia woda, and from whose ashes they ex-
tracted a substance, which they called tdkalif for making soap. The term kali'w used
by German chemists to denote capstic potash ; and kalium, its metallic basis ; instead
of our potash and potastium.
KANGAROO. A marsupial animal, native of Australia. Its tail makes excellent
soup, and its skin, when tanned, becomes a soft and durable leather.
KAOLIN (7>rr« a poredaine, Fr.; Porz^anerde, Germ.) is the name given by the
Chineae to the flne white clay with which they fabricate the biscuit of their porcelains.
See Clay and Porcelain Clat.
KARABI:/, a name of amber, of Arabic origin, in use upon the Continent
K ARN. A Cornish miner's term, frequently, according to Borlase, used to signify
the solid rock ; — more commonly a pile of rocks.
KARSTENITK The name given by Hatu to anhydrous sulphate of lime.
KATTIMUNDOO or CUTTEMUNDOO. A caoutchouc like substance obtained
fh>m the Euphorbia aniiquontm of Roxburgh. It was first exhibited in this country
m the Great Exhibition of 1851, being sent by Mr. W. Elliott from Vizagapatam.
It was of a dark brown colour, opaque except in thin pieces, hard and somewhat
618 EERMBS GRAINS.
brittle at common temperatnres, but easily softened by beat Perfectly insolnble in
boiling water, bat becoming soft, viscid, and remarkably sticky and adhesiTc like bird-
lime, reassaming, as it cools, its original character.
It is said to be nsed for joining metal, fastening knifb-handles, &o.
KEDGE ANCHOR. A sm^l anchor with an iron stock used for warping.
KEELER. A manager of coal barges and colliers in the Durham and Northum-
berland district
KEG. A cask containing fire gallons.
KEEVE, a mining term. A large vat used in dressing ores: also a brewer't term
for a mash tab.
KEIIl. A boiler used in bleaching establishments. See Blsacbino.
KELP ( Varec, F. ; Wareckt Germ.) is the crude alkaline matter produced by
incinerating various species of fuci, or sea-weed. They are cut with sickles from tiie
rocks in the summer season, dried and then burned, with much stirring of the pasty
ash. Dr. Ure analysed many specimens of kelp, and found the quantity of soluble
matter in 100 parts of the best to be from 53 to 62, while the insoluble was from 47 to
38. The soluble consisted of —
Sulphate of soda S-O 19-0
Soda in carbonate and sulphuret • '■ - 8*5 5*5
Muriate of soda and potash - - - - 36*5 87'5
The insoluble matter consisted of— ^^"^ ^^"^^
Carbonate of lime 24*0 10*0
Silica 8-0 CM)
Alumina tinged with iron oxide ... 9*0 10*0
Sulphate of lime 0-0 9-5
Sulphur and loss ------ 6*0 8-5
100-0 lOO'O
The first of these specimens was from Heisker, the second from Rona, both in the Isle
of Skye. upon the property of Lord Macdonald. From these, and many other analyses
which were made by Dr. Ure, it appears that kelp is a substance of very Tariable
composition, and hence it was very apt to produce anomalous results, when employed
as the chief alkaline flux of crown glass, which it was for a very long period. The
Fucus vesiculosus and Fucus nodosus are reckoned to afford the best kelp by incineratioo ;
but all the species yield a better product when they are of two or three years* growth
than when cut younger. The varec made on the shores of Normandy contains almost
no carbonate of soda, but much sulphate of soda and potash, some hyposulphite of
potash, chloride of sodium, iodide of potassium, and chloride of potassium ; the average
composition of the soluble salts being, according to M. Gay-Lussac, 56 of chloride of
sodium, 25 of chloride of potassium, and a little sulphate of potash. The Tery low
price at which soda ash, the dry crude carbonate from the decomposition of sea salt,
IS now sold, has nearly superseded the use of kelp, and rendei^ its manufacture
utterly unprofitable. When the common sea wrack, commonly used for prodneing
kelp, is incinerated in a closed crocible it gives a charcoal termed vegetable eihiopt,
KERMES GRAINS, ALKERMES, are the dried bodies of the female insects of
the species Coccus ilicist which lives upon the leaves of the Quercus ilex (prickly oak).
Kirby and Spence, and also Stephens, state that the Coccus ilicis is found on the
Quercus coccifera. The word kermes is Arabic, and signifies little worm. In the
middle ages, this dye stuff was therefore called vermicvlus in Latin, and Termeil and
vermilion in French. It is curious to consider how the name vermilion has been nnce
transferred to red sulphuret of mercury.
Kermes has been Imown in the East since the days of Moses ; it has been employed
from time immemorial in India to dye silk ; and was used also by the ancient Greek
and Roman dyers. Pliny speaks of it under the name of coccigranum^ and says diat
there grew upon the oak in Africa, Sicily, &c, a small excrescence like a bud, called
cuscuUum ; that the Spaniards paid with these grains half of their tribute to the
Romans ; that those produced in Sicily were the worst ; that they served to dye porple ;
and that those firom the neighbourhood of Emerita in Lusitania (Portugal) were the best.
In Germany, during the ninth, twelfth, thirteenth, and fourteenth centuries, the rural
serfs were bound to deliver annually to the convents a certain quantity of kermes,
the Coccus polonicus, among the other products of husbandry. It was collected fh>m the
trees upon St. John's day, between eleven o'clock and noon, with religions oeremonies,
and was therefore called Johannishlui (Saint John's blood), as also German cochineat
At the above period, a great deal of the German kermes was consumed in Venice, for
dyeing the scarlet to which that city gives its name. After the discovery <^ America,
cochineal having been introduced, began to supersede kermes for all brilliant red dyes.
EIMERID6E CLAY. 619
The principal TUieCies of kermes are the Coccus quercut, the Coccut pcfonkut^ the
OoocfufiagaruBy and the Cooeut uva wrsL
The CoecuM quercua iDsect lives m the soath of Eorope opon the kermes oak. The
female has no wiDga, is of the siie of a small pea, of a hrownish-red colour, and is
corered with a whitish dost From the middle of May to the middle of 'Jane the eggs
are collected, and exposed to the vapoar of vinegar, to prevent their incubation. A
portion of eggs is left npon the tree for the maintenance of the brood. In the
department of the Boaches-dn-Rhone, one half of the kermes crop is dried.
The kermes of Poland, or CocciMfK)iiNiiCTM, is found upon the roots of the Scleranthut
pereMtts and the Sderantluis aiinuitf, in sandy soils of that country and the Ukraine.
This species has the same properties as the preceding; one pound of it according to
Wolfe, being capable of dyeing 10 pounds of wool ; bnt Hermstaedt could not obtain a
fine colour, although he employed 5 times as much of it as of cochineal. The Turks,
Armenians, and Cossacks dye with kermes their morocco leather, cloth, silk, as well
as the manes and tails of their horses.
The kermes called Coccus fragaria is found principally in Kberia, npon the root of
the common strawberry.
The Coccus wa icr<t is twice the siae of the Polish kermes, and dyes with alum a fine
red. It occurs in Russia.
Kermes is found not only upon the Lycopodium oomplanaium in the Ukraine, but npon
a great many other plants.
Good kermes is plump, of a deep red colour, of an agreeable smell, and a roogh and
i>Qngent taste. Its colouring matter is soluble in water and alcohol $ it becomes yel-
owish or brownish with acids, and violet or crimson with alkalies. Sulphate of iron
blackenait With alum it dyes a blood red; with copperas, an agate grey; with
anlphate of copper and tartar, an olive green ; with tartar and salt of tin, a lively cin-
namon yellow ; with more alum and tartar, a lilac ; with sulphate of line and tartar, a
violet Scarlet and crimson dyed with kermes were called ffriUn colours. The red
cape for the Levant are dyed at Orleans with equal parts of kermes and madder, and
occasionally with an addition of Braxil wood. Kermes is but little used in England
at present as a dyeing substance.
KERMES MINERAL. Pure mineral kermes is regarded by Berzelius, Fuchs,
and Rose, as an amorphous tersolphoret of antimony. As the preparation has no
use in the arts or manufactures, for its mode of preparation and its chemical consti-
tution we refer to Ure*s Dictionary of Chemistry.
KERMESITE. Red antimony ore, composed of oxygen, 5'29; antimony, 74*45 ;
sulphur, 20*49.
KERSEY. A coarse stuff woven from long wool, diiefiy manufiictured in the
north of England.
KERSEYMERE. Commonly spelt cassimere. A fine fabric woven plain from
the finest wools, a manu&cture of the west of England principally.
KHAYA. One of the largest and handsomest trees growing on the western
coast of Africa. The wood is of fine quality, and of a reddish colour like mahogany.
KI ABOCCA WOOD, called also Amboyna wood. This wood is said to be the
excrescence or burr of ike Pterospermum indicum^ or of the Pterocarpus draco from
the Molaccas, the Island of Borneo, Amboyna, &c
KIBBLE, « mining term. A bucket usually made of iron, in which the ore is
drawn to the surface from the depths of the mme.
KILLAS. The name given by the Cornish miners to the clay slate of that district
It varies very much in colour and character, bemg sometimes of a clay-white, and at
other times grey or blue. It is in one district soft ; in another, compact and hard.
According to the character of this rock, the miner determines on the probability of the
mineral veins which traverse it being metalliferous or the contrary.
KILN (Four, Fr. ; Ofen^ Germ.) Is the name given to various forms of Aimaces
and stoves, by which an attempered heat may be applied to bodies ; thus there are
hrick-kilns, hop-kilns, lime-kilns, malt-kilns, pottery-kilns. See Brick, LiMSfiTONE^
Malt, Pottbrv, for a description of their respective kilns.
KIMERIDGE CLAY. The sands which underlie the Portland Stone of Dorset-
shire, and the south-west of England, are based npon a considerable thickness of
dark brownish or bluish-grey clay, to which the term Kiroeridge Clay has been
given by geologists, from the circumstance of its being largely developed and well
displayed in the neighbourhood of the village of that name.
Throughout the Isle of Purbeck,but especially in the part of it in question, the clay
assumes a very shaly and bituminous character, sometimes passing into more massive
beds olt brownish sbaly coal, possessing a conchoidal fracture.
The Romans, and also the Celts who inhabited the countrv previously to its in-
vasion by the former nation, appear to have manufiictnred the harder portions of the
620
EIMERID6E CLAY.
shale into cups and other articles, bat, chiefly into beads, armlets, and bracelets, spe-
cimens of which last haye been foond in the neighbooring barrows, in some cases
still encircling the wrists of skeletons.
Circular dircs of shale, about the size of a penny piece, have also been dug up in great
numbers in this part of the Isle of Purbeck : as many as 600 were, npoa one occa-
sion, found closely packed together.
Authorities haye been much divided in opinion as to the origin and use of these
circular pieces of shale; by. some they are supposed to have passed current as money^
or tokens, whence the name of Kimeridge coal-money, by which the^ are commonly
known, has been applied to them ; but, the most probable supposition is, that they
were the portions of the material &Eed to the lathe, and left adhering to it after the
armlets or other ornaments of a similar description had been turned from their outer
circumferences, and that at some subsequent period these refuse pieces of the turner
were worn as amulets or charms by the superstitious.
The shale around Kimeridge abounds in animal and yegetable matter, the former
consisting of the shells of oysters, ammonites, £m^, together with the bones and teeth
of large saurians and fish ; while the latter is in so finely divided a stato as not to be
distinguishable to the eye. Much carbonate of lime and pyrites are also present,
especially in those portions in which animal remains are most abundant.
The variation in the external character of the shale is accompanied by a corre-
sponding variatibn in the relative proportions of mineral and organic matter contained
in it ; those portions which are the most fissile and slaty containing a large proportion
of mineral matter combined with a relatively small proportion of organic matter; while
on the other hand, in the harder and more massive portions which break with a eon-
choidal facture, the organic matter is greatiy in excess of the mineral matter, as is
shown by the following analyses.
Amount of volatile matter • - . -
" " mineral matter - - -
Greytsh-green deliatelj fU-
•ile shale.
A.
idalfractore.
B
19-51
80-49
52-8
47-2
73-3
26-7
100-00
100-0
100-0
When heated the shale gives off copious fumes of a disagreeable odour resembling
that of petroleum ; and when ignited, it bums of itself with a dull smoky flame, leaving,
when freely exposed to the atmosphere, a reddish ash, which generally retains the form
of the origmal fragment
The shale has long been used for ftiel by the people of the district where it occurs,
and the ashes left after combustion have long been known to the ftmners on the coast
to exercise a beneficial iofluence upon their crops, especially turnips ; but the un-
pleasant smell given out by it when burning has prevented it ftom being used except
by the poorer inhabitants.
Within the last few years works were established at Wareham, for the purpose of
extracting naphtha and other products from the shale by distillation; but the manu-
facture was abandoned in consequence of the impossibility of destroying the smell
given out by the naphtha.
This defect having now, it is believed, been overcome, the works have lately been
re-opened, and are now being carried on with every prospect of success.
The chemical composition and properties of the shale have been recenUy thoroughly
investigated by Dr. Hofmann, of the Government School of Mines.
The following results were obtained by him from the distillation of the shale, at a
high temperature, for the purpose of producing gas : —
Amount of gas, water, ammonia, &c. - - - 63*5
Amount of coke ....... 36-5 — 100*0
The shale distilled in a gas retort ftumished a gas composed of: —
Olefiant gas and congeners - - - - - 8-8
Light carburetted hydrogen and hydrogen - - 69*3
Carbonic oxide - - - - - - - 9-7
Carbonic acid ------- 6'2
Sulphuretted hydrogen ..... 7«o — loo-O
SIMERIDGE CLAY. 621
The compofiition of tbis gas, fireed fW>m carbonic acid and salphnretted hydrogen,
by passing through an ordinary lime purifier, was as follows : —
defiant gas and congeners - - - - •10*0
Light carbnretted hydrogen and hydrogen - - 79*0
Carbonic oxide ....... 11*0—100*0
The composition of the coke produced was :<—
Carbon - - . - 7S'i - . - 72*8
Ash ... - 34-8 - - - 80-3
107-7 103-1
The excess abo^e 100 arises from the presence of sulphides in the coal, which
during the process of incineration absorb oxygen 'and are oonyerted into sul-
phates*
A ton of shale Aimished 11,300 cubic feet of this purified gas, the illuminating
power of which, used in an argand burner, consuming 5 cubic feet per hour, equalled
that of 20 sperm candles, while the percentage of coke remaining was 36*5.
The liquid and solid products obtained by the distillation of the shale at a low tem-
perature, are an offensively smelling, dark brown oil, suspended in an aqueous liquid,
charged with sulphuretted hydrogen, carbonic acid, and ammonia.
This oil, purified and distilled with water, fhmishes an oily liquid hesTier than
water ; a tar-like residue being left in the retort.
The oily liquid which, when purified, gives out the odour of the finest varieties of
coal-gas naphtha, is a mixture of several chemical substances.
When treated with concentrated nitric acid, this oily liquid is divided into two por-
tions, one of which is dissolved by the acid, while the other insoluble portion floats on
the surface of the solution in the form of a light colourless oily liquid, resembling in
its general character the hydrocarbons of Boghead coal-tar oil, and of petroleum.
The nitric solution which forms the larger proportion of the oily liquid, when
mixed with water, furnishes a dense, heavy, yellowish oil, with the odour of nitro-
benzoL
Hence it appears that the oily liquid obtained by the distillation of the shale consists
chiefly of benzol and its homologues, mixed with small quantities of petroleum
hydrocarbons. When sufficiently purified it is applicable for all the purposes for
which benzol is employed, for dissolving india-rubber and gutta-percha, for re-
moving stains firom fieibrics, for preparing varnishes, for making artificial oil of
almonds, &c.
On subjecting to distillation without water, and at a rather high temperature, the
oily tar-like residue remaining in the retort after the crude volatile liquid obtained by
heat from the shale had been distilled with water, other volatile products are
obtained.
The first portion of the oil obtained during the distillation is of an amber colour
when first distilled, and much less limpid than the oil produced by distillation with
water. It also possesses an offensive sulphurous smell, which however is lost on ex-
posure to the air, while the oil assumes a much darker colour. This oil is acted upon
by sulphuric, nitric, and hydrochloric acids, by which, especially by the first, a portion
of it is resinifled.
The remaining portion of the oil, when washed with water and afterwards distilled
with steam, fUmishes a perfectly colourless oil with the properties of paraffine. This
last oil, which forms but a small fraction of the original oil, behaves in all respects
like the paraffine oil obtained from Boghead cannel coal, and is applicable to
the lubrication of machinery, and all the other purposes to which that liquid is
applied.
The black, pitch-like, coky residue left in the retort resembles in general character
the coke produced from coal in the manufiicture of gas.
The ash of the incinerated coke contains nearly the same proportions of silica,
alumina, and iron as Portland cement. The foUowmg is an axudysis of the ash left
by the shale which contains the larger amounts of nuneral matter : —
Ash of Dorietthire thale. Portland oemeat.
Insoluble residue
Peroxide of iron
SiUca
Alumina -
Lime
Carbonic acid
2901
7-10
•
5-30
21-75
-
22-23
10-60
.
7-75
20-62
-
54*11
10*92
-
3-16
100*00
622
KIBSCHWASSER.
The distillAtioii of the shale at alow temperatwre, for the porpos of obteiniiig the
liquid and solid volatile products, furnished the following results : —
Analysis of A.
" Mineral matter -
64-1
Coke
71*5 < Carhon ...
15-0
^ Hydrogen
2*4
Light oil (naphtha) -
27
Oily and solid vola-
—
Heayyoil,containingl '3
tile products
14-6
per cent of paraffine
9-5
Residue of pitch
2-4
Gas, water, ammo-
nia, &c. -
13-9
- Gas, water, &c
13-9
100-0
100H>
Analysis of B.
Coke
43*0
Mineral matter -
L Carbon - - .
23-5
19-5
Oily and solid vola-
tile products
39-0 j
' Light oil (naphtha) -
Heavy oil, coDtainiiigl'9
per cent of paraffine
2-3
36-7
Gas, water, &c -
180
f Gas, water, ammonia,
&c - - -
18-0
100-0
100-0
The manufacture of the shale at Wareham, according to Mr. John C. Maosel, is
conducted in the following manner : —
The retorts are charged with about 5 cwt of shale, previously broken into pieces
about two inches square, and the temperature is maintained as nearly nniform as
possible. In order to obtain the required uniform temperature the retorts are con-
structed so as to have backs of molten lead. The gas formed in the retorts is then
condensed by means of a leaden worm, and the product is a crude oil ; a large quantity
of gas is made during this operation, which is not condensed, but used for ordinary
purposes. The crude oil is allowed to stand in long tanks for 48 hours, for the pur-
pose of letting the ammoniacal water (of which there is a large quantity) subside.
The oil is then put into a still, and rectified once or twice as the case may be. The
first product is a light oil, making overproof 75^; the next products are heavy oilSi
containing paraffine, which is now in great request by manufiu^turers.
The shale, on bein^ taken out of the retorts, is placed in close vessels, and whoi
cool is ground in a mill for mannre. In its unmanufactured state the shale is not
sufficiently rich in ammonia for this purpose ; but at this stage the artificial mannre
is as valuable as Ichaboe guano, both having been recently analysed for the purpose
of comparison. By keeping the temperature low in the retorts neither the phosphates
nor the organic matter are destroyed.
The name has been changed from Kimeridge shale to South Boghead coal by the
manufiicturers, the failure of the late company (by whom the former designation was
used) having, it was considered, rendered the alteration expedient The term South
Boghead ceil was selected from the resemblance to the Boghead coal <^ Scotland,
now so extensively worked near Edinburgh. — H. W. B.
KING WOOD is imported from the Brazils, and is sometimes called violet wood.
This is one of the most beautiful of the hard woods, and b used in small cabinet work.
KINIC ACID. A peculiar acid extracted bv Vauquelin from cinchona.
KINO is an extract obtained most probably from the Pterocarpua wiarM»pmm^
which grows on the Malabar coast In India, kino is used for dyeing cotton a
nankeen colour. It is of a roddish-brown colour, has a bitter styptic taste, and con-
sists of tannin and extractive, 75 parts, and a red gum, 25 parts. It is used only as an
astringent in medicine. Kino is often called a gum, but most improperly sa
KIP. A Malacca weight for thi, of 40 lbs. 1 1 oz. avoirdupoise. — SimmomU.
KIPS. The tanners call the skins of young animals kips. -
KIRSCHWASSER, is an alcoholic liquor obtained by fermenting and distOIing
bruised cherries, called kirtchen in German. The cherry usually employed in Switzer-
land and Germany is a kind of morello, which on maturation becomes black, and baa a
kernel very large in proportion to its pulp. When ripe, the fhiit, being made to fall
by switching the trees, is gathered by children, thrown promiscuously, unripe, ripe, and
KREOSOTE. 623
rotten, into tate, and cntBhed either bj hand, or with a wooden beater. The mashed
materials are set to ferment, and whenever this process is complete, the whole is trans-
ferred to a still, and the spirit is mn off, by placing the pot over the common fireplace.
The fermented mash is usually mouldy before it is put into the alembic, the capital
of which is lated on with a mixture of mud and dong. The liquor has accordingly, for
the most part, a rank smell, and is most dangerous to health, not only from its own crude
essential oil, but from the prussie acid derived from the distillation of the cherry-stones.
There is a superior kind of kinefupaaMer made in the Black Forest, prepared with
fewer kernels, from choice fruit, properly pressed, fermented, and distilled.
KIRWANITE. A mineral found in basalt on the north-eastern ooast of Ireland,
consisting of silica, lime, alumina, and protoxide of iron.
KNIFE CLEANING MAGHINE& Mr. Kent's machine for this purpose con-
Msts of a box or case, containing a conple of wooden discs, fixed near to each other
npon a horosootal iron rod or spindle, which passes through the case, and is caused to
rotate by means of a winch-handle. Each disc is, for about three-fourths of the area of
its inner face, covered with alternate rows of bristles and strips of leather; and the re-
maining fourth part is covered with bristles only. The knife-blades to be cleaned are
introduced through the openings in the case, between the rubbing surfaces of the discs ;
and rotatory motion being given to the discs by a winch-handle, the knives are ra-
pidly cleaned and polished.
Mr. Masters constructed knife-cleaning machines upon the same plan as the above ;
bat the rubbing surfiice of each disc is formed of strips of buff leather, with only a
narrow circle of bristles around the edge of each surfiiee, to clean the shoulders of tbe
knives; small brushes are fixed beneath the holes in the case, through which the
blades of the knives are inserted, to prevent the exit of dust from the apparatus.
Mr. Price has also devised a machine for cleaning knives, and another for cleaning
forks. The knife-cleaner consists of a horizontal drum, covered with pieces of leather
or felt, and fixed within another drum or circular ftuming, lined with leather or felt.
The knives are introduced through openings, in a movable circular plate, at the front
of the outer casing, and enter between the snr&ces of the two drums. The plate is
fixed upon a horizontal axis, which extends through the case, and is Axmished at the
back with a handle; by turning which the disc is caused to rotate and carry round the
knives between the sur&ces of the drums. The fork-cleaner consists of a box, with a
long rectangular opening in the side; behind which two brushes are fixed, face to face.
Between these brushes the prongs of the forks are introduced, and the handles are
secured in a carrier, which is made to advance and recede alternately by means of
a throw-crank, and thereby thrust the prongs into and draw them out of contact with
the brushes. The carrier consists of two metal plates, the lower one carrying a cushion
of vulcanised indiarubber for the fork handles to rest upon, and the upper being lined
with leather; they are hinged together at one end, and are connected at the other,
when the handles have been placed between Uiem, by a thumb-screw.
KNOLLS. A mining term in Germany for lead ore separated frx>m the smaller parts.
KNOPPERN are excrescences produced by the puncture of an insect upon the
flower-cups of several species of oak. They are compressed or flat, irregularly pointed,
generally prickly and hard; brown when ripe. They abound in Sty ria, Croatia, Sclavonia,
and Natolia ; those from the latter country being the best They contain a great deal
of tannin, are much employed in Austria for tanning, and in Germany for dyeing fawn,
grey, and black. See Gaixs.
KOUMISS is the name of a liquor which the Galmucks make by fermenting mare*s
milk, and from which they distil a fkvourite intoxicating spirit, called rack or racky.
The milk is kept in bottles made of hides till it becomes sour, is shaken till it casts
up its cream, and is then set aside in earthen vessels, in a warm place to ferment, no
yeast being required, though sometimes a little old koumiss is added. 21 pounds of
milk put into the still affoM 14 ounces of low wines, from which 6 ounces of pretty
strong alcohol, of an unpleasant flavour, are obtained by rectification.
KOURIE WOOD. The wood of the New Zealand pine Dammara AugtraHa, one
of the most magnificent of the coniferous woods. It is also called cowdie and kaurie
wood. It is much used for the masts of ships.
KRAMEBI A. A* shrub, which is a native of Peru, yielding the well-known
rhatany root, often used as a dentifrice.
KREOSOTE, or CREOSOTE. One of the many singular bodies discovered by
Reichenbach in wood tar. It derives its name from XP^ <^i^d v«{W, I preserve, in allu-
sion to its remarkable antiseptic properties. A great deal of confusion exists in the pub-
lished accounts of wood creosote, owing to the variable nature of the results obtained by
the chemists who have examined it This confusion is not found with that from coal, wh ich
ondoubtedly contains two homologous bodies, C'^H'O' and C'^H^O* ; the first being car-
bolic, and the second cresylic acid. The composition of carbolic acid has long been
624 LABYRINTH.
known, owing to the researches of Laurent: cresylic acid was recently discorerad hf
Williamson and Fairlie. Commercial coal creosote sometimes consists 'almost entirely of
cresylic acid. Coal oils, of very high hoiliug point, contain acids apparently homoiogaes
of carbolic acid, higher up in the series than even cresylic acid, and yet perfectly soiable
in potash. — {GreviUe WUlianu,') There is little donbt that wood creosote consists
essentially of the same substances as that from coaL The great difference in the
odour arises chiefly from the fact of the product from coal retaining with obstinacy
traces of naphthaline, parroline, and chinoline, all of which are extremely odorous.
No creosote found in commerce is ever perfectly homogeneous, nor, in &ct, is it neces-
sary that it should be so. If perfectly soluble in potash and acetic acid of the density
1 '070, and if it does not become coloured by exposure to the air, it may be considered
pure enough for all medicinal purposes. The oils from wood and coal tar may be
made to yield creosote by the following process. The oils are to be rectified until
the more volatile portions (which are lighter than water) hare passed orer. As
soon as the product running from the still sinks in water the receirer is to be
changed, and the oils may be received until the temperature required to send orer
the oil is as high as 480^ F. The oil so obtained is to be dissolved in caustic soda,
all insoluble ih it being rejected. The alkaline solution, after being mechanically
separated, as f)ur as possible, from the insoluble oil, is to be boiled for a very short
time. Two advantages are gained by this operation, — any volatile bases become
expelled, and a substance which has a tendency to become brown on keeping, ia
destroyed. Sometimes the oil on treatment with potash yields a quantity <^ a
crystalline paste. This is naphthaline, and should be remoyed by filtration trough
coarse calico or canvas. The alkaline liquid is then to be supersaturated with dilute
sulphuric acid, on which the creosote separates and rises in the form of an oil to the
suHlace. This creosote is already free from the greater number of impurities, and,
if rectified, may be used for many purposes. To obtain a purer article the operations
commencing with solution in caustic soda are to be repeat^ If the alkaline solution
on boiling again becomes coloured, the purification must be gone through a third time.
It is essential not to boil the alkaline solution long, or a serious loss of creosote would
take place. According to Reichenbach the boiling point of creosote is 397^. Carbolic
acid boils between 369° and 370°. Cresylic acid boils at 397°. From this it would
appear that Reichenbach's creosote consisted of cresylic acid. The specific gravity
of creosote according to Reichenbach is 1*037 at 68°. That of carbolic acid is 1'065
at 64°. Carbolic acid and its homologues, when mixed with quicklime and exposed to the
air, yield a beautiful red colour, owing to the formation of rosolic acid. — C G. W.
KRYOLITE. SeeCBYouTB.
KY ANITE. A stone, which is sometimes blue and transparent It is then employed
as a gem ; it resembles sapphire. Its chemical composition is, silica, 37*0 ; alumina,
63-0.
KYANOL. The old name of aniline. It was applied by Runge to the base from
coal tar.— C. G. W.
KYROSITE. An arsenide of copper, from Briocios, near Annaberg.
L.
LABDANUM. A resin found on the leaves of the Ciitus CrtHcus^ in Candia. It
is used in perfumery and for pastiles.
LABRADORITE. Opaline or Labrador felspar is a beautiiVd mineral* with
brilliant changing colours, blue, red, and green, &c. Spec. gray. 2*70 to 2 '75.
Scratches glass ; affords no water by calcination ; fusible at &e blowpipe into a
frothy bead ; soluble in muriatic acid ; solution affords a copious precipitate with
oxalate of anunonia. Cleavages of 93^° and 86p ; one of which is brilliant and
pearly. Its constituents are, silica, 55*75 ; alumina, 26*5 ; lime, 1 1 ; soda, 4 ; oxide
of iron, 1*25 ; water, 0*5.
Labradorite receives a fine polish, and the beauty of its chatoyant refleetioDs re-
commends it as an article of ornament — H. W. B.
LABURNAK. Cytisut Laburnam. (Arbois Commim, Fr. ; GoldregeMj Germ.)
The wood of the labumam tree is sometimes used in ornamental cabinet-work and
in marquetry. " In the labumam there is this peculiarity, namely, that the medullary
plates, which are large and very distinct are wlute, whereas the fibres are a dark brown,
a circumstance which gives an extraordinary appearance to this wood.*' — Aikm*
LABYRINTH, in Metallurgy, means a series of canals distributed from the lead
of a stamping-mill ; through which canals a stream of water is transmitted lor aos-
pendiog, carrying off, and depositing, at different distances, the ground ores. See
Mbtallubot.
LAC.
625
LAC (^Laquej Fr. ; Zack^ Lackfarhen^ Germ.) A. retinons sabstance produced
bj the pnnctare of a peculiar female insect, called Coceu» lacca or ficuM^ upon the
branches of seyeral plants ; as the Ficus religiosOf the Fieus Indica^ the Bhamnusjuptba^
the Croiom ktccifirum or bihar tree, and the Buteafrondoaa or the pepel tree, which
grow in Siam, Assam, Pegu, Bengal, and Malabar. The twig becomes thereby
incmsted with a reddish mammillated resin, haying a crystalline-looking fracture.
The female lao insect is of the size of a louse ; red, round, flat, with 12 abdominal
circles, a bifurcated tail, antenn«B, and 6 claws, half the length of the body. The male
is twice the above size, and has 4 wings ; there is one of uem to 5000 females. In
November or December the young brood makes its escape from the eggs, lying be-
neath the dead body of the mother ; they crawl about a little way, and fasten them-
seWes to the bark of the shrubs. About this period the branches often swarm to
such a degree with this Termin, that they seem covered with a red dust ; in this case,
they are apt to dry up, by being exhausted of their juices. Many of these insects,
however, become the prey of others, or are carried ofP by the feet of birds, to which
they attach themselves, and are transplanted to other trees. They soon produce
small nipple-like incrustations upon the twigs, their bodies being apparently glued,
by means of a transparent liquor, which goes on Increasing to the end of March, so
as to form a cellular texture. At this time the animal resembles a small oyal bag,
without life, of the sise (^ cochineal. At the commencement, a beautiful red liquor
only is perceived, afterwards eggs make their appearance ; and in October or Novem-
ber, when the red liquor gets exhausted, 20 or 30 young ones bore a hole through the
hack of their mother, and come forth. The empty cells remain upon the branches.
These are composed of the milky juice of the plant, which serves as nourishment to
the insects, and which is afterwards transformed or elaborated into the red colouring
matter that is found mixed with the resin, but in greater quantity in the bodies of the
insects, in their eggs, and still more copiously in the red liquor secreted for feeding
the young. After the brood escapes, the cells contain much less colouring matter.
On this account, the branches should be broken off before this happens, and dried in
Uie sun. In the East Indies this operation is performed twice in the year ; the first
time in March, the second in October. The twigs encrusted with the radiated cellular
substance constitute the sHck-lac of commerce. It is of a red colour more or less
deep, nearly transparent, and hard, with a brilliant conchoidal fracture. The stick-lac
of Siam is the best ; it often forms an incrustation fully one quarter of an inch thick
all round the twig. The stick-lac of Assam ranks next ; and, last, that of Bengal,
in which the resinous coat is scanty, thin, and irregular. There are three kinds of
lac in commerce : stick-lac, which is the substance in its natural state, seed-lac, and
shell-lac According to the analysis of Dr. John, stick-lac consists, in 120 parts, of
An odorous common resin - 80*00
A resin insoluble in ether - 20*00
Colouring matter analogous to
of that cochineal . - - 4*50
Bitter balsamic matter - - S'OO
Dun yellow extract - - - 0*50
Acid of the stick-lac (lacdc acid) 0*7 5
Fatty matter, like wax - - 3*00
Skins of the insects, and colour-
ing matter - - - •2*50
Salts « - - - - 1-25
Earths ----- 0*76
Losa - - - ■ - - 4*75
120*00
According to Franke, the constituents of stick-lao are, resin, 65*7 ; substance of the
lac, 28*3 ; colouring matter, 0*6.
Seed-lac,^ When the resinous concretion is taken off the twigs, coarsely pounded,
and triturated with water in a mortar, the greater part of the colouring matter is dis-
solved, and the granular portion which remains being dried in^ the sun, constitutes
teed'lac. It contains of course less colouring matter than the stick-lac, and is much
less soluble. Mr. Hatehett's analysis of seed-lac was as follows : —
Resin . . •
Colouring matter -
Wax -
Gluten - . .
68
10
6
5*5
Foreign bodies
Loss
6-5
4
100
John found in 100 parts of it, resin, 66*7 ; wax, 1*7 \ matter of the hie, 16*7; bitter
balsamic matter, 2*5 ; colouring matter, 8*9 ; dun yellow extract, 0*4 ; envelopes of
insects, 2-1 ; laccle acid, 0*0 ; salts of potash and lime, 1*0 ; earths, 6*6 ; loss, 4*2.
ShtU'lac,— In India the ieed-hc is put into oblong hags of cotton doth, which are
held over a charcoal fire by a man at each end, and, as soon as it begins to melt, the
hag is twisted so as to str^n the liquefied resin through its substance, and, to make
it drop upon smooth stems of the banjan tree {Mu9a paradiMo), In this way, the
resin spreads into tiiin pUtes, and constitutes the sabstanoe known in oommeroe by^
the name of ahdl-lac.
Vol. IL S S
626 LAC-DYE.
The Pegu Btiek-]ac» being rery dark ooloored, fdraishes a sbell-lac of a conrespood-
ing deep hoe, and therefore of inferior Talae. The palest and finest shell-lac ia hroo^^
from the northern Cvear, It contains yery little colouring matter. A stick-lae of an
intermediate kind comes from the Mysore country, which yields a brilliant lao-dye
and a good shell-Iae.
Sheu-lac, by Mr. Hatchett's analysis, consists of resin, 90*5 ; colouring matter, 0*5 ;
wax, 4*0 ; gluten, 2-8 ; loss, 1*8 ; in 100 parts.
The resin may be obtained pure by treating shell-lac with cold alcohol, and filtering
the solution in order to separate a yellow grey puWerulent matter. When the alco-
hol is again distilled off, a brown, translucent, hani, and brittle resixi, of specifie gravity
1*139, remains. It melts into a viscid mass with heat, and diffuses an aromatae
odour. Anhydrous alcohol dissoWeait in all proportions. According to John, it con-
sists of two resins, one of which dissolves r^idily in alcohol, ether, the volatile and
&t oils ; while the other is little soluble in cold alcohol, and is insoluble in ether and
the volatile oils. Unverdorben, however, has detected no less than four differeot re-
sins, and some other substances in shell-lac. Shell-lac dissolves with ease in dilute
muriatic and acetic acids ; but not in concentrated sulphuric acid. The resin of shell-
lac has a great tendency to combine with salifiable bases ; as with caustic potash, which
it deprives of its alkaline taste.
This solution, which is of a dark red colour, dries into a brilliant, transpaient red-
dish brown mass ; which may be re-dissolved in both water and aloohoL B7 passing
chlorine in excess through the dark>coloured alkaline solution, the lac-resin is precipi-
tated in a colourless state. When this precipitate is washed and dried, it fonns, wkh
alcohol, an excellent pale-yellow varnish, especially with the addition of a littU tor-
pentine and mastic.
With the aid of heat, shell-lac dissolves readily in a solution of borax.
The substances which Unverdorben found in shell-lac are the following z
1. A resin, soluble in alcohol and ether ;
2. A resin, soluble in alcohol, insoluble in ether ;
8. A resinous body, little soluble in cold alcohol ;
4. A crystallisable resin ;
5. A resin, soluble in alcohol and ether, but insoluble in petroleum, and unerya-
tallisable.
6. The unsaponified fat of the coectu insect, as well as oleic and margaric aeida.
7. Wax.
8. The laceine of Dr. John.
9. An extractive colouring matter.
Shell-lac is largely used in the manu&ctnre of sealing wax and vamiahefl, and for
japanning.
LAC-DTE, Lac Lake, or cake-lac, is the watery infhsion of the ground stick -lac,
evaporated to dryness, and formed into cakes about two inches square and half an
inch thick. I>r. John found it to consist of colouring matter, 50 ; resin, 25, and
solid matter, composed of alumina, plaster, chalk, and sand, 22.
Dr. Macleod, of Madras, states that he prepared a very superior lac-dye from
stick-lac, by digesting it in the cold in a slightly alkaline decoction of the dried leaves
of the MemecyUm tinctonum (perhaps the m, capitdlatum, from which the natives of
Mahibar and Ceylon obtain a saffron yellow dye). This solution bein^ used along
with a mordant consisting of a saturated solution of tin in muriatic acid, was found
to dye woollen cloth of a very brilliant scarlet hue.
The cakes of lac-dyc imported from India, stamped with peculiar marks to designate
their different manufacturers (tAe hcMt DT, the second JMcR, the third CEX ure now
employed in England for dyein^f scarlet cloth, and are found to yield an equallj bril-
liaut^ colour, and one less easily affected by perspiration tlum that produced by
cochineaL When the lac-dye was first introduced, sulphuric acid was the aolvent
applied to the pulverised cakes, but as muriatic (hydrochloric) acid has been found
to answer, it has to a great extent supplanted it A good so/cent (No. 1) fortius
dye-stuff may be prepared by dissolving 3 pounds of tin in 60 pounds of muriatic acid,
of specific gravity 1*19. The proper mordant for the cloth is made by mixing 27
poonds of muriatic acid of sp. gr. 1*17, with 1^ pounds of nitric acid of 1*19 ; pvttiog
this mixture into a salt-glazed stone bottle, and adding to it in small bita at a tioM,
grain tin, till 4 pounds be dissolved. This solution (No. 2) may be used within
twelve hours after it is made, provided it has become cold and dear. F<w dyeing ;
three quarters of a pint of the solvent No. I is to be poured upon each pound of the
pulverised lao-dye, and allowed to digest upon it for six hours. The doth before
being subjected to the dye bath, most be scoured in the miU with foller^s earth. To
dye 100 pounds of pelisse cloth, a tin boiler of 800 gallons capadty should be filled
nearly brimfol with water, and a fire kindled under it Whenever die temperatore
LACE MANUFACTURE.
627
riies to 150^ Fahr., a handful of bnm, and half a pint of the solution of tin (No. 2)
are to be introduced. The froth, which rises as it approaches ebullition, must be
skimmed off; and -when the liquor boils, 10^ pounds of lac-dye, previously mixed with
7 pints of the solvent Na 1, and 3} pounds of solution of tin No. 2, must be poured
in. An instant afterwards, 10^ pounds of tartar, and 4 pounds of ground sumach,
both tied up in a linen bag, are to be suspended in the boiling bath for five minutes.
The fire being now withdrawn, 20 gallons of cold water, with 10^ pints of solution of
tin being poured into the bath, the cloth is to be immersed in it, moved about rapidly
daring ten minutes ; the fire is to be then re-kindled, and the cloth winced more
slowly through the bath, which must be made to boil as quickly as possible, and
maintained at that pitch for an hour. The cloth is to be next washed in the river ;
and lastly with water only, in the fulling milL The above proportions of the ingre-
dients produce a brilliant scarlet tint, with a slightly purple cast If a more orange
hue be wanted, white Florence argal may be used, instead of tartar, and some more
sumach. Lac-dye may be substituted for cochineal in the orange-scarlets.
To determine the tinctorial power of lac-dye by comparison with proved samples, a
dye-bath is prepared as follows : — 5 grains of argal, 20 grains of flannel or white cloth,
5 grains of lac-dye, 5 grains of chloride of tin, 1 quart of water. Heat the water to
the boiling point in a tin or china vessel ; add thereto the argal, and then the piece of
doth or flannel. Weigh off 5 grains of the lac-dye and pulverise it in a Wedgewood
mortar, with the 5 grains by measure of chloride of tin, and pour the whole into the
hot liquor containing the cloth, taking care to rinse the mortar with a little of the
hot liquor ; keep the whole boiling for about half an hour, stirring the cloth or
flannel about with a glass rod ; then withdraw the cloth, wash and dry it for com-
parison. — Normmubf,
In the former edition was a table of the imports and exports of lac-dye and lac-
lake, which show that in 1802 only 253 lbs. were imported, which rose, however, in
1837, to 1,01 1,674 lbs.; the imports, &c., for the last three years being —
Lac-dte :—
British £. Indies
Other parts -
SHELIrLAC: —
United States
British £. Indies
Other parts
Seed lac - •
Stick lac
I8&6.
Cwtt.
9,343
81
9,424
722
20,822
123
21,667
613
6,595
1856.
Cwts.
10,704
271
10,975
13,847
919
14,766
613
1,151
1857.
Cwts.
11,767
429
12,196
1,152
18,399
185
19,736
356
2,665
LACCIC ACID crystallises, has a wine- yellow colour, a sour taste, is soluble in
water, alcohol, and ether. It was extracted from sUck-lac by Dr. John.
LAOCINE is the portion of shell-lac which is insoluble in boiling alcohol. It is
brown, brittle, translncid, consisting of agglomerated pellicles, more like a resin than
anything else. It is insoluble in e&er and oils. It has not been applied to any use.
LACE BARK The reticulated bark of the Lagetta Untearia, This splits into
fibres, which reSemble lace.
LA CE MANUFACTURE. The pillow-made, or bone-lace, which formerly gave
occopation to multitudes of women in their own houses, has, in the progress of me-
chanical invention, been nearly superseded by the bobbin-net lace, manufactured at
first by hand-maehines, but recently by the power of water or steam. Bobbin-net
maybe said to surpass every other branch of human industry in the complex ingenuity
of its machinery ; one of Fisher*s spotting frames being as much beyond the most
curious chronometer in multiplicity of mechanical device, as that is beyond a common
roasting-jack. — Ure.
The threads in bobbtn>net lace form, by their intertwisting and decussation, regular
hexagonal holes or meshes, of which the two opposite sides, the upper and under, are
directed along the breadth of the piece, or at right angles to the selvage or border. <
Fig. 1054 shows how, by the crossing and twisting of the threads, the regular six-sided
mesh is produced, and that the texture results from the union of three separate sets of
threads, of which one set proceeds downwards in serpentine lines, a second set pro-
ceeds flrom the left to the right, and a third from the right to the left, both in slanting
88 2
628 LACE MANUFACTURE.
direetloni. These oblique threads twist themselyes round the Tertxeal onei, and abo
cross each other betwixt them, in a peculiar manner. This may be readilj understood
by examining the representation. In comparing bobbin-net with a common web, the
perpendicnlar threads in the figure, which are parallel to the border, may be regarded
as the warp, and the two sets of slanting threads as the weft
1054 1055
These warp threads are extended up and down, in the original moonting of the
piece between a top and bottom horizontal roller or beam, of which one is called the
vcurp beam, and tho other the lace beam, because the warp and finished laoe are woond
upon them respectiyely. These straight warp threads receire their contortion from
the tension of the weft threads twisted obliquely round them alternately to the ri^t
and the left hand^ Were the warp threads so tightly drawn that they became m-
flexible, like fiddle-strings, then the lace would assume the appearance shovn in
Jig, 1055 ; and although this condition does not really exist, it may serre to illustrate
the structure of the web. The warp threads stand in the positions a a, a' a', and
a^' a"\ the one half of the weft proceeds in the direction b b,y V, and b" l/*\ and the
second crosses the first by running in the direction c c, or c' e\ towarda the opposite
side of the fabric If we pursue the path of a weft thread, we find it goes on till it
reaches the outermost or last warp thread, which it twists about; not once, aa with the
others, but twice; and then returning towards the other border, proceeda in a rererse
direction. It is from this double twist, and by the return of the weft threads, that the
selvage is made.
The ordinary material of bobbin-net is two cotton yams, of frota. No. 180 to Na 250,
twisted into one thread ; but sometimes strongly twisted single yam haa been used.
The beauty of the fabric depends upon the quality of the material, as well aa the regu-
larity and smallness of the meshes. The number of warp threads in a yard in breadth
is from 600 to 900; which is equivalent to from 20 to 30 in an inch. The size of the
holes cannot be exactly inferred from that circumstance, as it depends partly upon the
oblique traction of the threads. The breadth of the pieces of bobbin-net varies from
edgings of a quarter of an inch to webs 12 or even 20 quarters, that is, 2 yards wide.
Bobbin-net lace is manufactured by means of very costly and complicated machines,
called yrame«. The limits of this Dictionary will admit of an explanation of no more
than the general principles of the manufacture. The threads for crossing and twisting
round the warp, being previously gassed, that is, freed from loose fibres by aingeiag
with gas, are wound round small pulleys, called bobbins, which are, with thia view,
deeply ^^rooved in their periphery. Fig», 1056, 1057, exhibit the bobbin alone, and with
its carriage.
In the section of the bobbin a, fig, 1056, the deep groove is shown in whieh the
thread is wound. The bobbin consists of two thin discs of brass, cut out in a stamp*
press, in the middle of each of which there is a hollow space c. These diaea are
riveted together leaving an interval between their edge all round, in which the thread
is coiled. The round hole in the centre, with the little notch at top, serves for spitting
them upon a feathered rod, in order to be filled with thread by the rotation of that
rod in a species of reel, called the bobbin-filling madiiae. fiMh of these boblntts
/about double the size of the figure) is inserted mto the vacant space o of the car>
riage,^. 1057. This is a small iron frame (also double the size of the figure), which.
at e «, embraces the grooved border of the bobbin, and by the pressure of the afiring
at f, prevents it from falling out This spring serves likewise to apply aofiEieienl
friction to the bobbin, so as to prevent it from giving off its thread at ^ by ita xolatioii.
LACE MANUFACTURE.
629
tulen a certain imall force of traction be employed upon the thread. The cnrriliDear
grooTC k hf rank in each &oe or side of the carriage, has the depth shown in the sec-
1057
1056
tion at A. The grooye corresponds to the interral between the teeth of the comb, or
bars of the bolt, m which each carriage is placed, and has its moyement A portion
of that bolt or comb is shown at a, Jig, 1058 in plan, and one bar of a circular bolt ma-
chine at 6, in section. If we sup-
pose two snch combs or bolts
placed with the ends of the teeth
opposite each other, bnt a little
apart, to let the warp threads be
stretched, in one yertlcal plane,
between their ends or tips, we shall
haye an idea of the skeleton of a
bobbin-net machine. One of these
two combs, in the doable bolt ma-
chine, has an occasional lateral
moyement called shagging, eqnal to
the interral of one tooth or bolt,
hj which, after it has receiyed the
bobbins, with their carriages, into
its teeth, it can shift that interyal to
the one side, and thereby get into
a position to return the bobbins,
with their carriages, into the next
aeries of interstices or gates in
the other bolt By this means the
whole series of carriages receiyes successiye side steps to the right in one bolt, and
to the left in the other, so as to perform a species of counter march, in the course
of which they are made to cross and twist round about the yertical warp threads, and
thus to form the meshes of the net
The number of moyements required to form a row of meshes in the double tier
machine, that is, in a frame with 2 combs or bars, and 2 rows of bobbins, is six ; that
is, the whole of the carriages (with their bobbins) pass from one bar or comb to the
other six times, during which passages the different diyisions of bobbin and warp
threads change their relatiye positions 12 times.
This interchange or trayersing of the carriages with their bobbins, which is the most
difficult thing to explain, but at the same time the most essential principle of the lace-
machine, may be tolerably well understood by a careful study of fig. 1059, in which the
simple line J represents the bolts or teeth, the sign ^ the back line of carriages, and the
sign f the uont line of carriages, h is the front comb or bolt bar, and i the back bolt
128456789
1059
I..
wm
►i »< »'
iui:
yi^
bar. The former remains always fixed or stationary, to receiye the carriages as they
may be presented to it by the shoggmg of the hitter. There must be always one odd
carriage at the fad ; the rest being in pairs.
88 3
630 LACTIC ACID.
No. 1 represents the carriages in the front comb or bar, the odd carriage being at the
left end. The back line of carriages is first moved on to the back bar i, the odd
carriage as seen in No. 1, having been left behind, there being no carriage opposite to
drive it over to the other comb or bar. The carriages then stand as in No. 2. The bar
I now sbifis to the left, as shown in No. 3 ; the front carriages then go over into the
back bar or comb, as is represented by No. 4. The bar i now shifts to the right, and
gives the position No. 5. The front carriages are then driven over to the front bar, and
leave the odd carriage on the back bar at the right end, for the same reason as before
described, and the carriages stand as shown in No. 6. The bar i next shifts to the
left, and the carriages stand as in No. 7 (the odd carriage being thereby on the back
bar to the left). The back carriages now come over to the front bar, and stand as in
No. 8. The back bar or comb i shifts to the right as seen in No. 9, which eom-
pletes the traverse. The whole carriages with their bobbins have now changed their
position, as will be seen by comparing No. 9 with No. 1. The odd carriage. No. 1,
0 has advanced one step to the right, and has become one of the front tier ; one of
the back tier or line ^ has advanced one step to the left, and has become the odd
carriage ; and one of the front ones ^ has gone over to the back line. The bobbins
and carriages thronghoot the whole width of the machine have thns erosaed each ocher^s
coarse, and completed the mesh of net.
The carriages with their bobbins are driven a certain way fhmi the one comb to
the other, by the pressure of two long bars (one for each) placed above the Level of
the comb, until they come into such a position that their projecting heels or catches
t iyjig, 1057, are moved off by two other long flat bars below, called the locker plates,
and thereby carried completely over the interval between the two ccnnba.
There are six different systems of bobbin-net machines. I. Heatbcoate*s patent
machine. 2. Brown's traverse warp. 3. Morley's straight bolt 4. Clarke's pusher
principle, single tier. 5. Leaver's machine, single tier. 6. Morley's circular bolt. All
the others are mere variations in the construction of some of their parta. It is a
remarkable fact, highly honourable to the mechanical judgment of the late Mr. Moriey
of Derby, that no machines except those upon his circular bolt principle have been
found capable of working successfully by mechanical power.
The circular bolt machine (comb with curved teeth) was used by Mr. Moriey fcr
making narrow breadths or edgings of lace immediately after its first invention, and
it has been regularly used by the trade for that purpose ever since, in conseqae&ee of
the inventor having declined to secure the monopoly of it to himself by patent At
that time the locker bars for driving across the carriages had only one plate or blade.
A machine so mounted is now called, " the single locker circular bolt" In the year
1824, Mr. Moriey added another plate to each of the locker bars, which was a great
improvement on the machines for making plain net, but an obstruction to the mijEing
of narrow breadths upon them. This machine is now distinguished from the foim^
by the term ** double locker."
A rack of lace, is a certain length of work counted perpendicularly, and contains
242 meshes or holes. Well-made lace has the meshes a little elongated in the direc-
tion of the selvage.
Mr. Heathcoate's machine, invented in 1809, was the first sneceasfol laee-making
machine.
Mr. Moriey patented his in 1811, and in the same year Messrs. Mari and Clarke in-
vented the pusher machine, and Messrs. Leaver and Turton, of New Radford, brought
forward the lever machine. In 1817, Mr. Heathcoate applied the rotatory movenent
to the circular bolt machine and mounted a manufactory at Tiverton on this plan,
where the lace manufSftcture is still carried on extensively.
LACTIC ACID, C»H'20". Syn. Nanceic acid. (^cm/« lac^qmt, Fr. ; MUdumurt,
Germ. ) Discovered by Scheele in sour milk. Subsequently, M. Braconnot examined
the sonr liquid which floats above starch during its manufocture, also the acidified de-
coctions of various vegetables^ including beet-root, carrots, peas, &C., and fbimd an acid
which he considered to be peculiar, and consequently named the nanceic The acid
formed under all these circumstances turns out to be the same ; it is, in fact, lactic acid,
which modem researches show to be a constant product of the fermentation of sugar,
starch, and bodies of that class. The acidity of sauerkraut is due to the presence of the
same substance. Liebig has recently extended and confirmed the experiments made
many years ago by Berzelius, on the presence of lactic acid in the juice of flesh, but
he denies its existence in urine, as asserted by MM. Cap and Henry, and others.
Preparation. — Lactic acid can be prepared easily in any quantity by the fermenta-
tion of sugar. Care must be taken, however, that the process does not go too fiu*,
because lactic acid undergoes with facility another decomposition, by whii^ it becomes
converted into butyric acid. The following process of M. Bensch for the preparation
of lactate of lime can be recommended by the author of this article as yieldiqg at a
LACTOMETER. 631
nsall troable and expense a Teiy large quantity of product In iiict, he has prepared
with ilMsility upwards of three pints of butyric acid fh>m lactate of lime obtained in this
manner. DIssoItc 6 Ibe. of lump sugar, and half an ounce of tartaric acid in two
gallons and a half of boiling water. Leaye for a day or two, and then add two ounces
of rotten cheese, and a gallon of skimmed milk stirred up with three pounds of
well washed prepared chalk. The temperature should not fall below 86^ F. nor rise
aboTe 95^. The water lost b^ eyaporation must be made up by adding a little every
few days. After a time, Tarying fit>m ten days to a month, according to the tempe*
mtnre and other circumstances, the whole becomes a magma of acetate of lime. Two
gallons of boiling water must then be added, and half an ounce of quicklime and the
whole, after being boiled for half an hour, is to be filtered through a linen or flannel
bag. The filtered liquid is to be CTaponUed until it begins to get somewhat syrupy,
the fluid in diis state being put aside to allow the salt to crystallise. The crystals,
afterbeingsligfatly washed with cold water, are to be recrystallised two or three times.
To obtain lactic acid from the lactate of lime, it is necessary, in the flrst place, to
GcmTert the latter salt into that of sine Fur this purpose a crude lactic acid is first
obtained thus : to every ta'O pounds three ounces of lactate of lime dissolved in twice
ha weight of boiling water, seven ounces of oil of vitriol previously diluted with twice
its volume of water are to be added. The boiling fluid is to be stramed through a linen
bag to remove the precipitate of gypsum, and tibe filtered liquid is to be boiled for 15
minutes with 8} ounces of carbonate of zinc. The boiling must not be continued
longer, or a suMalt of sparing solubility would be produced. The liquid, which is to be
filtmd boiling, will deposit on cooling the lactate of zinc in colourless crystals, which
are to be washed with a little cold water, and after being drained are to be dried by ex-
posure to the air on frames covered with filtering paper. The mother liquid will
yield a firesh quantity of lactate if it be boiled with the salt remaining on the filter
and evaporated.
From the lactate of zinc the acid is to be separated by passing sulphuretted hy-
drogen through the solution of the salt in eight times its weight of boiling water.
The gas is to be expelled by heat, and the fluid on evaporation yields pure syrupy
lactic acid.
Lactic acid is a colourless syrupy liquid of a powerful pure acid taste. Its specific
gravity is 1*215. It is bibasic, consequently the general formula for the lactates is
Ci'H>«Oi*,2MO ; M representmg any metal
The most important salts of lactic acid are those of zinc and lime. The former salt
IS that generally formed in examining animal or vegetable fluids with a view to the
isoU^ion of the acid. It is found with two different quantities of water according to
the circumstances under which it is prepared, and it is worthy of remark that the
amount of water of crystallisation remarkably affects the solubility of the salt in water
and alcohoL
Lactic acid is produced from alanine by the action of nitrous acid according to the
following equation : —
2C«H»N0« + 2N0« - C"H>H)" + 4N + 2HO.
* , » '^ ^
Alanine Lactic add.
Anhydrous lactic acid, CH^K)**, ib produced by the action of heat on the syrupy
acid. Lactic acid is considered by chemists to be constructed on the type of four
atoms of water in which two atoms of hydrogen are replaced by the radical lactyl.
thus: —
H. }0*-
The other two atoms of hydrogen are consequently basic It has been said that
lactic acid may, by fermentation, be converted into butyric acid ; the following equa-
tion represents the metamorphosis:
C»ff«0" = C«HK>* + iCO* + 4a
^ , » ^ , »
Lactic acid. Butyric acid.
An the butyric acid employed for the preparation of butyric ether, or pine-apple
essence, is now prepared by the fermentation of lactate of lime. — C. G. W.
LACQUER, IS a varnish, consisting chiefly of a solution of pale shell-lac in alcohol,
tinged with si^Sron, annotto, or other colouring matters. See Vabnisu.
LACTOMETER is the name of an instrument for estimating the quality of
milk, called also a Gaiactometer, The most convenient form of apparatus would be
a series of glass tubes each about 1 inch in diameter, and 12 inches long, graduated
through a space of 10 inches, to tenths of an inch, having a stopcock at the bottom,
and suspended upright in a frame. The average milk of the cow being poured in to the
height of 10 inches, as soon as the cream has all separated at top» the thickness of its
§84
632 LAMP-BLACK
1>ody maj be metsvred by the scale ; and then the skhn-mUk may be rm off telov
into a hydrometer glass, in order to determine its density or relative ridmess ineaseoot
matter, and dilation "with water.
LACUSTRINE FORMATION (a geological Urm), Belonging to a lake.
L AKESb Under this general title is included all those pigments which are prqand
by combining vegetable or animal colouring matter with earths or metallic oiidfi
The general method of preparation is to make an infusion of the substance, andtoidd
thereto a solution of common alum ; or sometimes, when it has been necessaiy to
extract the colouring matter by the agency of an acid, a solution of alom ntunted
with potash. At first, a slight precipitate falls, consisting of alumina and the edoariog
matter; but if some alkali is added the precipitate is increased. Some edom^
ing matters are brightened by alkalies ; then the decoction of the dye^off ii made
in an alkaline liquor, and being filtered, a solution of alum is poured into it Where
the affinity of the colouring matter for the subsulphate of alumina is great, alnmlBi
recently precipitated is agitated with the decoction of the colouring body. The muQ*
facture of lakes depends on the remarkable property possessed by alumina, of com-
bining with and separating the organic colouring matters from their solationa
Red Lakes. — The finest of these is Cabmine, which, as carminated kkes, called
lake of Florence, Paris, or Vienna, is usually prepared by taking the Uqaor de-
canted from the carmine, and adding freshly precipitated alumina to it The mixtare
js warmed a little, briskly agitated, and allowed to settle. Sometimes alom is dissolTed
in the decoction of cochineal, and then the alumina precipitated by potash ; bat the
colour is not good when lakes are thus prepared, and to improve it the dyer^a sohtioo
of tin is often added. A red lake may be prepared from kermes in a similar maoBer.
Brazil wood yields a red lake. The wood is boiled in a proper quantity of vaier
for 15 minutes, and then alum and solution of Un being added, the liqaor ii to be
filtered, and solution of potash poured in as long as it occasions a precipitate. This
is separated by a filter, the powder well washed, and being 'mixed with a little gum
water, made into cakes. Sometimes the Brazil wood is boiled with rinegar instead of
water. An excess of potash produces a lake of a violet colour, and cream of taitar
gives it a brownish hue.
Madder is much used in the preparation of lakes.
The following process is recommended : —
Diffose two pounds of ground madder in four quarts of water, and after a maeera*
tion of 10 minutes strain and squeeze the grounds m a press. Repeat this maeeratioD,
&C., twice upon the same portion of madder. It will now have a fine rose cotoar. It
must then be mixed with five or six pounds of water and half a poond of braised
alum, and heated upon a water-bath for 3 or 4 hours, with the addition of vater, ai
it evaporates ; after which the whole must be thrown on a filter doth. The liquor
which passes through is then to be filtered through paper, and precipitated by car-
bonate of potash. If potash be added in three successiye doses, three different lak(»
will be obtained of diminishing beauty. The precipitates must be washed ontil the
water comes off colourless, then with gum water made into cakes.
YeUow Lakes are made with decoctions of Persian or French berries, to which aonw
potash or soda is added ; into the mixture a solution of alum is to be poared co long
as any precipitate falls. Quercitron will yield a yellow lake, provided the decoctM«
is purified by either butter-milk or glue. Annotto lake is formed by disaohing tlua
substance in a weak alkaline lye, and adding a solution of alum to the solution.
Lakes of other colours can be prepared in a similar manner $ but true lakes of other
colours are not usually manufactured.
LAMINABLE is said of a metal which may be extended by passing betveen
steel or hardened (chilled) cast-iron rollers.
In the manufacture of rail and bar iron, laminated iron is rolled to{^her at a
welding heat, until the required bar or rail is formed (see Bails). lliisiSie^^
under the best possible circumstances, a defective manufacture. The onion of tbe
bars is never absolutely complete, and the result of the long^continued action of tiawi
of carriages upon all rails is the development of the laminated plates, which freqMOtif
peel off, layer after layer, to the destruction of the rail,*and to the great danger of tw
traveller. Railway iron should be rolled into form from perfectly homogeneousmasaa
of metal This lamination of iron rails has been laid hold of by those who advocate
the hypothesis that the slate rocks owe Uieir lamination to mechanical P^J^J^
whereas it is evidently the result of an imperfect manufacture. See Rollwo "^
LAMIUM ALBUM, or the dead nettle, is said by Leuchs to aflbrd in its Iea7«»
greenish-yellow dye. The L. purpureum dyes a reddish-grey with salt of tui, ana
greenish tint with iron liquor. .
LAMP-BLACK. Every person knows that when the combustion of oil m « '^P
Is imperfect it pours forth a volume of dense black soot According to the qnanwy
XAMPS.
633
cf earbon oontttned in the material employed, ao is the iiluminating power of tbe
flame produced by oombnstion. It, therefore, we haye a Tery brilliant flame, and we
aulgect it to any conditions which shall impede the progress of the combination of the
earbon with the oxygen of the air, the resalt is at once the formation of solid carbon,
or lamp-black. Tms is exhibited in a remarkable and often an annoying manner by
the camphine lamp. If oil of turpentine, resin, pitch oil, or fkt oil, be burnt in lamps
under a hood, with either a rapid draught or an insufficient supply of air, the lamp-
black collects on the hood, and is occasionally removed. Sometimes a metallic roller,
generally of tin, is made to reyolve in the flame, and rub against a brush. By the
cooling mfluence of the metal, the heat of the flame is diminished, the combustion
retarded, and the carbon deposited, and in the reyolution of the cylinder swept off.
Camphor burning forms a very beautiful black, which is sometimes used as a
pigment.
The common yarieties of lamp-black are made from all sorts of reAise resinous
matters, and from the rejected fragments of pine trees, &c. In Germany, a long flue
is constructed in connection with the furnace in which the resinous substances are
burnt, and this flue communicates with a hood, composed of a loose woollen cloth, held
up by a rope passing over a pulley. Upon this the soot collects, and is from time to
time shaken down. In the best condocted manufactories about 3 cwt. of lamp black
is collected in each hood in about twelve hours. In England, lamp-black is sometimes
prepared from the refuse cokinff coal, or it is obtained in connection with coke ovens.
The lamp-black, however, obtamed flrom the combustion of coal or woody matter is
never pure. See Bone Bulck, Ivobt Black.
liAMP, DAVY. See Safety Lamp.
LAMPS. Under Illumination, will be found some notices of several kinds of
lamps, with especial reference to the quantity of ligfht produced by them.
Lamps are very varied in form, and equally varied in the principles involved. A
brief description, however, of a few of the modem varieties most suffice.
Tlu moderator katp. — The spiral spring has recentiy been introduced into the mo-
derator lamps, for the purpose of forcing the oil up the wick of the lamp. This will be
understood by the following description and drawings : — ^q^q
The distinguishing character of the moderator lamp is the di-
rect transmission of the power, in the reservoir of oil, to tbe
resistance offered by the weight of the column of oil, as it
rises to the cotton ; — and secondly, the introduction of a rec-
tangular regulator, which equilibrates constantiy by the resist-
ance of the oil and the force applied to raise it. In the reservoir
( fig. 1060), is a spiral spring which presses on the disc or piston,
Jflsi. 1061, which is furnished with a valve opening downwards.
This spring is attached to a tooth rack, worked by a pinion
wheel, by the means of which it is wound up. The mechanical
force of the spring is equal to firom 15 to 20 pounds ; and as this
force is exerted upon the disc, floating on Uie oil, this is forced
up through the tube, and it overflows to the argand burner, tho-
roughly saturating the cotton, and supplying a constant stream of
oiL This oil falls back into the reservoir, and is, of course, above
the disc. When the spring has run down, it is again wound
np ; and then the valve opening downward allows the oil to
flow back beneath the disc, to be again forced up through the
tube. As the pressure employed is so great, the oil would,
hot for the "moderator," now over with too much rapidity.
This moderator, or regulator, is a tapering rod of iron-wire,
which is placed in the ascending tube ; and, as the pressure
increases, it is forced more into it, and checks the flow of oil ;
whereas as it diminishes it falls, and being tapering, allows
more oil to rise. Several ingenious adjustments are introduced
into these lamps, as maniuactured by the Messrs. Tylor of
Warwick Lane, with which we need not at present deal The
cylinders containing the oil are covered with cases in metal
or sometimes of porcelain. Two drawings of these are shown
U*9' 1062 and jff^r. 1063). These lamps admit evidentiy of yet
more elegant forms than have been given them. The^ urn-
shaped, from the antique, in very pure taste, is the last intro-
duction of the house above named. • a v i.
It would be tedious to enumerate the various modifications of form and action to which
the oil lamp has been subject, previous to ite arrival at what may be deemed its per-
fect construction by Argand. The discovery of the mode of applying a new prmciple
1061
6M LAMPS.
br thi* indindoal not only produced m en.ire rer<dnti<HL in tbe msDofhctiiTe at tbe >r-
licle, but threatened vitb nun all thoKi>)u.m the patent exdnded tram partici|Htian
1^-2 063 *" *^ "" tnde ; ao mnch *o indeed,
that Argand, vko had not been ap-
prenticed to tbe bwioesa, «>a pnb-
licly peraecnted b; the trnoera, lock-
amitba, and iroDmoogen, vbo dia-
paled hii right by any improveiBarta
to infringe tiie profin of their char-
tered vocation. " This invention," to
qnote a description of (he lamp pub-
lished lome yean ago, "ambracM so
many improvementi upon tbe COB-
mon lamp, and hu beoome ao gene-
ral throughout Europe, that it may
be justly ranked among the grealeat
diacoveriea of the age. Aa a tubati-
tote fir the candle, it ha* the »dnn-
tage of ^reat economy and eonve-
nlence, mtb mucb greater brilllaiMyi
and for the pnrpMe of prodncing beat,
it is an important inMrunent in th«
haadt of the chemiaL We may, viik
some propriety," eontinoei thit atitbo-
rity, " ooinpare the eommon lamp and
tlie candle to fire made in tbe open
air, without any forced method of
•applying it with oxygen; while
the Argand lamp may be compared
to a fire in a fomaee, in vhieh a
rapid supply of OKvgen ia fiuiiiahed
by the velocity of the aicesding enr-
rent. Tbia, however, ia not the only
advantage of thi* faluable inv«nljaa.
It ii obvtoot that, if the combortible
vapour occupiei a considerable area, tbe oxygen of the atmoadiere cannot comlHDe
vitb the vapour in the middle part of tbe ascending colnmn. The outside, tberefore.
il the only part vhich enters into combustioa; the middle coDititnting smoke. TliW
evil is obviated in the Argand lamp, by directing a enrrent of atmoapberic ur
through tbe flame, -which, instead of being raised Irom a aolid wick, is prodnoed
from a circular one, which snrroands the tube through which the air aaoenda.'
The mechanism of the Argand burner, in its present improved state, will be clearly
understood from the annexed fignrcs and explanation, whidi apply equally to estch ie-
■cription of the lamps hereafter described.
A,^g. 106*, is a brass tube, about 8J inches in length, and l^incb wide; within tUs
IQgf tube is placed another, n,
which is Boldered bat in-
side by the flange at c :
tbe space between these
tabes contains the oil sor-
whieh, being &eely ad-
^kg mitted from the reservoir
by the side pipes d x, rises
in the tnbnlar space, either
to a height corresponding
with its level in the reser-
voir, or at least so as to
maintain tbe wick in a
slate of constant aatnra-
tioo. Tbe tube b if of considerable thicknesa, having a spiral groove cat abo&t it
from top to bottom : v is a metallic ring made to slip over the tube n ; it containa a
riiort pin inside, which fits exactly into the spiral groove just mentioned: o is the
circular woven cotton wick, the lower end of which is drawn light upon the neck of tbe
ring ; H is a copper tube, with a slit nearly from top to boltom : it admita tbe ring
r, Bod beicg dropped over the inner tube B, exactly fits the inside of the wider tabe
\. by mcBDSof a narrow rim near the top at a, and auolberot the bottom 6: between
LAMPS. fi85
die upper run »nd the mar^D, there u a imiU |iKJectingplD ir, vbieh, nhentbeirhole
kpparaliu i* combiQed. Gib mto ihe csTitj t of the collar i. To prepare the lamp for
lue, the tube B ii placed between a and b, as jiut described : the ring t, with jta
charge of cotton, is next inierted, the pin in the inside falling into the spiral groove,
■nd thai on the outside entering the slit in the tube h, which, on being inmed about,
moTes the ring r down npon the screwed inner tube, until the wick only jurt rise*
above the soperior edges of the tabes, in Ihe inlerral between which it lies in the oiL
In this stage, the frtune I Is placed on Ihe nick in the collar at s, falling upon the piD
near the top of a : the lower disc/g, poising over the tube a. at once presents a
conieiueDt support for Ihe glass chimney, and a finger-hold for raising ibe irick. The
central tube is open thronghoat, commuDi eating; at its lower end, with the bras*
Teceptaele a ', the latter is perforated at top, to admit Ihe air which, by circulating
througb the above tube, and the hollow flame which snrroonds it, causes the lamp to
bum with that peculiar freedom and hriliiancy which distinguish the Argand con-
struction. This lasl -mentioned receptacle likewise catches any imall quantity of oil
which ma; pass over the inner lube during the combostion of the wick. L is the
brass peg, which fits into the upper part of the pillar, in the table lamp.
In addition to the endless variety of small portable lamps, the peculiarities of which
it would be ledious to particularise, and the merit of which, at compared wiih those
on the Argand principle, consisls, for the mosl part, in their cheapness, the more im-
portant article*, and those generally in demand, may be diatinguished aa fixed or
brackel lamps, lospended or chandelier lamps, and table ....
or French lamps — all these having bumen on the prin-
ciple above described. The former sort were, previous to
the introdactioD of gas, very common in shops. The
globe A (fy. 106S), which i« sometimei made plain and
lOBS
mbossed, as in the cut, screws off. when Ihe
oil Is poured in at an opening in the lower part, which
is afterwards closed by means of a slide altadied to
On stem, b. and the globe, thus replenished, is itiverted
•nd screwed into Ihe part, c. When the lamp is used,
the stem n is raised a little, and the oil is suffered to flow
through the inlermedisle Inbe into the cistern D, only at Ibe
rate at which it is cunsQaied by the burning of the wick.
The peculiar form of the glass chimney e is admirably
calculated to assist in the more complete combuBiion of
the Dialler drawn up to the wick when impnre oil is used,
a desideratum originallv in part secured by placing over
the central lobe, and m the midst of the flame, a cir-
cular metal plate, by means of which the ascending
column of air was turned oul of its perpendicular course,
and thrown immediately into that part of the Same where
the smoke is formed, and which by ibis ingenious con-
trivance is eCTeclualty consumed ; this application, how-
ever, is not necessary, nor the form of much moment,
when purified sperm oil is used. These lamps being
usually made to move on a pivot at r, altached to the wall
or otber sapport, are very convenient in many situalions, as being easily advanced
over a desk or counter, and afterwards turned aside, when not in use.
636 LAMPIC ACID.
The Binnmbral lamp having passed out of use need not be described.
The use of spirit lamps followed, and we have the naphtha and camphioe lamps of
this order. The accompanying woodcut {fig, 1066) riiows the peciiliarity of the
camphine lamp where the reservoir of spirit (turpentine deprived of smell) is far
below the burner, to which it ascends by capillaiy attraction, through the tabes of the
cotton wick. Lamps to bum naphthas (^BJmontine, &c.} are constructed on the same
priociple.
One of the best oil lamps, is that known as Carcel's lamp.
In this lamp the oil is raised tiirough tubes by clock-work, so as continually to
overflow at the bottom of the burning wick ; thus keeping it thoroughly soaked, while
the excess of the oil drops back into the cistern below. I have possessed for several
Tears an excellent lamp of this description, which performs most satisfactorily ; but
It can hardly be trusted in the hands of a servant ; and when it gets at all deranged,
it must be sent to its constructor in Paris to be repaired. The light of this lamp,
when furnished with an appropriate tall glass chimney, is very brilliant, though not
perfectly uniform ; since it fluctuates a little, but always perceptibly to a nice ob-
server, with the alternating action of the pump-work ; becoming dimmer after every
successive jet of oil, and brighter just before its return. The flame, moreover, always
flickers more or less, owing to the powerful draught, and rectangular reverberatory
shoulder of the chimney. The mechanical lamp is, however, remarkable for con-
tinning to bum, not only with unabated but with increasing splendour for 7 or 8
hours ; the vivacity of the combustion increasing evidently with the increased tem-
perature and fluency of the oil, which by its ceaseless cireidation through the ignited
wick, gets eventually pretty warm. In the comparative experiments made upon
different lights by the Parisian philosophers, the mechanical lamp is commonly taken
as the standard. I do not think it entitled to this pre-eminence : for it may be
made to emit very different quantities of light, according to differences in the nature
and supply of the oil, as well as variations in the form and position of the chimney.
Besides, such lamps are too rare in this country to be selected as standards of ilia-
mination.
The following experiments by Dr. lire, are well worth preserving.
The great obstacle to the combustion of lamps lies in the viscidity, and consequent
sluggish supply of oil, to the wicks ; an obstacle nearly insuperable with lamps of the
common construction during the winter months. The relative viscidity or relative
fluency of different liquids at the same temperature, and of the same liquid at different
temperatures, has not, I believe, been hitherto made the subject of accurate researches.
I was, therefore, induced to make the following experiments with this view.
Into a hemispherical cup of platinum, resting on the ring of a chemical stand, I
introduced 2000 water-grain measures of the liquid whose viscidity was to be measured,
and ran it off through a glass siphon, I of an inch in the bore, having the outer leg 84
inches, and the inner leg 3 inches long. The time of efflux became the measure of
the viscidity ; and of two liquids, if the specific nuvity and consequent pressure
upon the siphon were the same, that time would indicate exactly the relative vis-
cidity of the two liquids. Thus, oil of turpentine and sperm oil have each very neariy
the same density; the former being, as sold in the shops, «= 0*876, and the latter from
0*876 to 0-880, when pure and genuine. Now I found that 2000 grain-measures of
oil of turpentine ran off through the small siphon in 95 seconds, while that quanti^
of sperm oil took 2700 seconds, being in the ratio of I to 28^ ; so that the fluency of
oil of turpentine is 28^ times greater than that of sperm oil Pyroxilic spirit, com-
monly called naphtha, and alcohol, each of specific gravity 0*825, were found to run
off respectively in 80 and 120 seconds *, showing that the former was 50 per cent
more fluent than the latter. Sperm oil, when heated to 265° Fahr., runs off in 300
seconds, or one-ninth of the time it took when at the temperature of 64^. Southern
whale oil, having a greater density than the sperm oil, would flow off faster were it
not more viscid.
2000 grain measures of water at 60° ron off through the said siphon in 75 seconds,
but when heated to 180° they ran off in 61.
Concentrated sulphuric acid, though possessing the great density of 1*840, yet flows
off very slowly at 64°, on account of its viscidity ; whence its name of oil of vitrioL
2000 grain-measures of it took 660 seconds to discharge.
LAMPIC ACID. Syn. Aldehydic acid ; Acetylous acid. ( Acide Lamptque^ Fr.)
If a little ether be placed at the bottom of a glass, and some spongy platinum attached
to a wire of the same metal be ignited and suspended about an inch frdm the fluid,
it will glow and continue to do so for a long time. On the other hand, if a spiral of
platinum wire be placed over the wick of a spirit lamp, and the latter be first ignited
and then blown out, the wire will continue at a red heat until all the spirit is exhausted.
Numerous sesqnioxides, when placed warm on wire gauze over capsules containing
LAPIDARY. 637
alcohol, will glow in the fame manner. Under all these circnmitaneeB, a powerful
odour resembling aldehyde is evoWed, which strongly affects the eyes. If this expe»
riment be made m such a manner that the Tolatile product may he condensed, it will
be found to he strongly acid. It is powerfully reducing in its tendency, and if heated
with the oxides of silver or gold, converts them into the metallic state, and the
liquid is found to contain acetic acid and resin of aldehyde. If, however, the acid
liquid he only very gently warmed with oxide of silver, a portion of the latter is dis*
solved ; but when baryta is added to precipitate the silver as oxide, and the fluid is
warmed, the metal instead of the oxide comes down, and the fluid when tested for the
nature c^ the acid, is found to contain nothing but acetate of baryta. These phe-
nomena are explained by some chemists by supposing the fluid to contain an acid
which they, following the late Professor Daniell, call the lampic, and supposed to con-
tain C*H^. When lampio acid is treated first with oxide of silver and then with
baryta water and heated, Uiey consider that the oxygen of the oxide of silver is trans-
fenred to the lampic acid, converUng it into acetic acid, which combines with the
baryta, while the metallic silver is precipitated. The following equation explains
the reaction supposed to take place: —
Cmny + BaO + AgO - C*H"0«,BaO + Ag + HO.
Lampic acid. Acetate of baryta.
The oonrersion of the lampio into acetic acid is therefore attributed to the oxidising
tendency of the oxide of silver. Those who regard the decomposition from the above
point of view, consider lampic acid to be acetylous acid, that is to say, to bear the
same relation to acetylic acid (acetic acid) that sulphurous acid does to sulphuric
acid.
The above explanation, although simple, does not really render a satisfactory
account of the reactions which bear upon the subject. Aldehyde, when treated with
oxide of silver does, it is true, become converted into the same, or apparently the
same, substance as lampic acid, but the probabilities are in £ftvour of Gerhardt*s suppo-
sition, that the lampates are in fact aldehyde, in which an equivalent of hydrogen is re-
placed by a metal. That the aldehydes are capable of uniting with metals with elimina-
tion of hydrogen has been, on more than one occasion, proved by experiment There
is great difliculty in preparing the sodium aldehyde of the vinic series, but the author
of this article has found that S euodic aldehyde from oil of rue be treated with sodium,
QnntiQii
a definite compound is formed, having the formula ^^ > .
If, therefore, we admit aldehyde to be formed on the hydrogen type, that is to say,
two atoms of hydrogen in which one is replaced by the oxidised radical acetyl, we
shall have for aldehyde : — H \ ' '"^^ ^*^' lampates, acetylurets, or aldehy-
dates: — ^ V . 31 Gerhardt, who views the lampates in the above light, regards
aldehyde as the true acetylous acid. See Acbttl.-— C. G. W.
LANCE WOOD. Uvaria lanceoHata or Ouatteria virgata. This wood is imported
from Jamaica and Cuba in long poles from 3 to 6 inches diameter. Lance wood is
paler in colour than box ; it is selected for elastic works, as ^g-shafts, archery bows,
springs, &c These are bent into the required form by boiling or steaming. Sur-
veyors rods, ordinary rules and billiard cues are made of lance wood.
LANDER. In mining, tlie man who attends at the mouth of the shaft to receive
the ** hibble of ore*' as it reaches the surfoce.
LAPIDARY, Art of. The art of the lapidary, or that of cutting, polishing, and
engraving gems, was known to the ancients, many of whom have left admirable spe-
cimens of their skilL The Greeks were passionate lovers of rings and engraved
stones ; and the most parsimonious among the higher classes of the Cyrenians are said
to have worn rings of the value of ten minae (about 302. of our money). By far the
greater part of the antique gems that have reached modern times, may be considered
as so many models for forming the taste of the student of the fine arts, and for in-
spiring his mind with correct ideas of what is truly beautiful. With the cutting of
the diamond, however, the ancients were unacquainted, and hence they wore it in its
natural state. Even in the middle ages, this art was still unknown ; for the four large
diamonds which enrich the clasp of the imperial mantle of Charlemagne, as now pre-
served in Paris, are uncut, octahedral crystals. But the art of working diamonds
was probably known in Hindostanand China in very remote periods. After Louis de
Berghen's discovery, in 1476, of polishing two diamonds by their mutual attrition, all
the finest diamonds were sent to Holland to be cut and polished by the Dutch artists,
who long retained a superiority, now no longer admitted by the lapidaries of London
and Paris. Se6 Diamond.
639 LAPIDARY.
Tbe operation of gem enlting ii abridged by tvo metbodi; I, by cleaitigc ; %
bj cutting off ilicva with a fine wire, coated with dismond powder, and fixed in
the itock of a hand-saw. Diamond U tbe only precioos itone which is cm and
poliihed with diamond powder, Makcd with oliTC oil npon a mill pUle of very mA
■leeL
OrienhJ rabiea, aappfaires, ajid topaiea, are cat with diamcind powder loahed with
olive oil, on a copper wbeeL Tbe fkceta thai formed are af\erwarda poliahed on
aoother copper wheel, wiEb tripoli, tempered with water.
Emeralds, hyaciniha, amelhyali, garnets, agates, and other softer slones, are cot at ■
le^ wheel, with emery aod water ; and are polished on a tin wheel with tripoli and
water, or, still better, on a lino wheel, with pnlty of lia and water.
The more tender preeioni (tonea, and even tbe pastes, are me on a mill-wheri of
hard wood, with emery and water ) and are poliihed with tripoli and water on anotfaer
wheel of hard wood.
ijince the lapidary employs always the same tools, whatever be the stone which be
CDta or polishes, and since the wheel discs alone vary, aa also the sabatuice he uses
with them, we shall describe, Eret of all, his appatitoi, and then the manipolatioiia fbr
diamond cutting, which are applicable to erery species of stone.
The lapidary'i mill, or wheel, ia shown in perspective in Jig. 1067. It eoasistt tjt
- a strong fhune made of oak carpentry, with
tenon and mortised joints, bound (ogvtber
with strong bolls and screw nnta. Its fbra is
a paraLelopiped of froia B to 9 feet long, by
from 6 to 7 high; and about S feel broad.
These dimensions are large enough to eoik-
taio two cutting wheels alongside of each
other, as represented in the fignre.
tUeudes the tno sole ban B B, ve petrov*
in the breadth, 5 cross hers, c, d, k, f. a
The two extreme bars c and o, ar« a part of
the frame-work, and serie to hind it. The
two cross-bftrs d and r, carry each in the
middle of their length, a piece of wood m
(hick as themselvei, bat only 4} inches long
(see /is. I06T),JoiDed solidly by mortises and tenons with that cross bar as well a>
with tbe one placed opposite on the other parallel face. These two piece* are called
nmmtrt (lintels) ; the one placed at D is tbe upper t the one at i the lower.
In^, 10G8 tbis&caisshowninside, in order to explain how the mill wheel is placed
and supported. The tune letters point out tbe same objects, both in the preceding and
tha following figures.
In each of (h«ae ammtrt a squats bole is cut out, exactly opposite to the other in
which are ndjnsCed by IViction a square piece of oak, a a,
Q 1068 Jv- 106^1 *boBe extremities are perfbrated with a oooieal
Fi hale, which receives the two ends of the arbor n of the
M wheel I, and fbimi its socket This square bar ia adjusted
at a convenient height by a double wooden wedge, tt.
The cross bar in the middle B, supports the table e r, a
atrong plank of oak. It is pierced with two lar^ bolca,
whose centres coincide with the centres of the coBieal holea
hollowed out at the end of the sqoare pina. These bolea
of about 6 inches diameter each, are intended lo let die
arbor pass iireely througli, bearing its respeetlTC wheeL
(See one of these holes at i, iaj!^. 107a below.)
Each wheel is composed of au iron arbor B.fig. 1068,
of a grinding wheel i, which differt in substtmce according
to ci^cu^^ItBnoe^ as already stated, and of the pnlley », fnr-
nished with several grooTcs (see fy. 1070), which has a
sqoare fit upon the arbor. The arbor carries a oollel d, on
which are 4 iron pegs or pins that enter into the wheel to
^^. The wheel plate, of which the grtnmd plan is shown at
^g E, is hollowed out towards its centre lo half its tUckncM)
^^^ when it is in its position on the arbor, as indicated in fig,
1069, a washer oi ferrule of wrought iron is put over it, and secured in its place by
a double wedge. In Jig. Iog9 the wheel-plate is repreaented in sectiosi, that tbe
connection of Ue whole parts may be seen.
A boud ff (see fig. 1067 and fif. 107S), about 7^ inchei hi^ h Cx«d to tbe
part of the frame oppoaite ti
. 1069
tt,M 1071).
The lover
1070
LAPIDAET. 639
le (ide *t which the lapidary vorki, aod it prerenlf
Che cnlting and polUhing from b«ing throwo to ■
distance by the cenCriftigal force of the irbeel-plate.
Behind thii apparatiu ia mounted for each grinding-plaW,
a large nheel I. (tetfig. 1067), limilar to a catler'i, bat placed
hwiioDtally. This whael is grooted round iu cireamfe
to Koeite an endleai cord or band, which pane* ronnd o
the gtootn of the polley J, Sied behiw the wheel-pUte. Hence,
Ml tainmg the fij-wheel i^ the plat« revolve* with * velocity
relative to the velocity commoaiwted to the wheel l. and to
the difference of diameter of Cbe wheel L and Ibe palley i.
Each wheel l, ii moonted dd an iron arbor, with a cnuk (Me
jwer [UTOt of Ibat arbor k ii conical, and tnntt in a
•ocket fixed in the floor. The great wheel i. rem on the ooUet
i, fhmiihed with iti 4 iron plni, for eecnnDg the coanection.
Above the wheel ao iron waiher it laid, and the whole it fixed by a double wedge,
which entere into the mortiie l,Jig. 1071.
Fig. 1073 exhibit! a ground-plui view of all 1073
thii asaemblage of parta, to explain the iCructure
ti the machine. Everything that itanda above
the apper ttaumtr-bar hai been suppreoed in thia
represeataCioo. Here we see the table c ci the
txiiftT tiBtma m ; the one wheel-plate ( the other
having been removed to ahow that the endlea oord
doei not cnici ; the two large wheel* l l, present
id each machine, the crank bar h, seen leparate
in /ig. 1073, which tervei for toniing the wheel i-
1073
Thi« bar if formed of S iron plate* a,oi p,q\ and q,Tifg. 1073). The firtt is
bent round at the point n, to embnwe the itud « i the aeeond pg,a of the lame
breadth andibickneu aathe flrtt; and the third, is adjnited to the latter with a hinge
joint, at the point q, where the; are both tnmed into a circular form, to embrace the
crank m. When all theae piece* are connected, they are fixed at the proper lengtba by
the bncklea or aquare ringa ttt, which embrace theae piece*, aa i* ahown \afig. 107S.
The Btad I, seen \a Jig. I0T3, is fixed to the point d, by a wedge-key npon the
arm p, represented se^rately, and in perapecdve, lafg. 1074. The labourer seising
1073
the two upright peg! or handlei * »; by the alternate forward and backward motion
of hia arm, bt eommonicate* the same motion to the crank rod, which transmits it to
the crank of the arbor m, and impreese* on that arbor, and the wheel which it bears,
a rotatory movemenL
Fig. 107S shows piece-meal and in perspective a part of the lajudary'a wheel-mill.
There we see the table e e, the grind plate i. whose axis is kept in a vertical position
by the two square pings aa, fixed into the two m«»ier» by the wedgM 4 ft. "O the
two ridetof the wheel-plate, we percdve aa important instrainent called a dml, which
640 LAPS.
lerres to hold the stone during the catting and polishing. This instmment has
oeiyed lately important ameliorations, to be described in Jig. 1076. The lapidary holds
this instrument in his hand, he rests it upon the iron pins u u, fixed in the taUe, lest
he should be affected by the velocity of the revoWing wheel-plate. He loads it some-
times with weights e e, to make it take better hold of the grinding plate.
Fig. 1076, shows an improvement made by one of the most expert lapidaries of
Geneva, whereby he cuts and polishes the facet with extreme regularity, converting
1076 ^^ ^^ A ^"^ ^i^^* £<^h of the two jaws bears a large conchoidal
Jy cavity, into which is fitted a brass ball, which carries on its uf^er
^^^ \ part a tube e, to whose extremity is fixed a dial-plate y/^ engraved
'^T^^j^^^^ \ with several concentric circles, divided into equal parts, Ulc the
Y^ 1 j toothed-wheel cutting engine-plate, according to the number of
^ ' f £Bicets to be placed in each cutting range. The tube receives with
=1 I moderate friction the handle of the cement rod, which is fixed at the
^^ n \ proper point by a thumb-screw, not shown in the figure, being eoa-
•j^— -| 1 cealed by the vertical limb d^ about to be described.
^ A needle or index g, placed with a square fit on the tail of the
cement rod, marks by its point the divisions on the dial plate yyi on the side m a,
of the jaw a, there is fixed by two screws, a limb d, forming a quadrant whose centre
is supposed to be at the centre of the ball. This quadrant is divided as usual into 90
degrees, whose highest point is marked 0, and the lowest would mark about 70 , for
the remainder of the arc down to 90 is concealed by the jaw. The two graduated
plates are used as follows : —
When the cement rod conceals zero or 0 of the limb, it is then vertical, and serves
to cut the table of the brilliant ; or the point opposite to it, and parallel to the table.
On making it slope a little, 5 degrees for example, all the facets will now lie in the
same zone provided that the incUnaUon be not allowed to vary. On taming roand
the cement rod the index g marks the divisions so that by operating on the circle
with 16 divisions, stopping for some time at each, 16 facets will have been formed, of
perfect equality, and at equal distances, as soon as the revolution is completed.
In cutting the stones, they are mounted on the cement-rod b,^. 1077, whose stem
is set upright in a socket placed in a middle of a sole piece at a, which receives the
1077 stem of the cement-rod. The head of the rod fills the
1078 cup o( JL, A melted alloy of tin and lead is poured into
the head of the cement-rod, into the middle of which the
stone is immediately plunged ; and wherever the solder
has become solid, a portion of it is pared off from the
top of the diamond, to give the pyramidal form shown in
the figure at b.
There is an instrument employed by the steel polishers
_ _ for pieces of clock work« and by the manufacturers of
^\ji, watch-glasses for polishing their edges. It consists of a
— solid oaken table Jig. 1078. The top is perforated with
two holes, one for passing through the pulley and the arbor of the wheel plate b
made either of lead or of hard wcwd, according to circumstances ; and the other c for
receiving the upper part of the arbor of the large pulley d. The upper pulley of the
wheel plate is supported by an iron prop e, fixed to the table by two wooden screws.
The inferior pivots of the two pieces are supported by screw sockets, working in an
iron screw nut sunk into the summer bar f. The legs of the table are made longer
or shorter, according as the workman chooses to stand or sit at his emi^oymenL
Emery with oil is used for grinding down, and tin putty or colcothar for polishing.
The workman lays the piece on the flat of the wheel plate with one hand, and presses
it down with a lump of cork, while he turns round the handle with the other hand.
See the different gems under their respective heads.
LAPIS LAZULL A silicate of soda, lime, and alumina, with the sulphide of
iron and sodium in minute quantities. This beautiful mineral is found in crystalline
limestone of a greyish coloiur, on the banks of the Indus, and in granite in Persia*
China, and Siberia.
The finest varieties are highly esteemed, being employed in the manafkctnre of
costly vases. It was also the source from which the beautiful pigment ultramarine,
was obtained, but this colour is now prepared artificially at a very cheap rato. See
Ultramarine.
LAPS. ^ Metal polishing wheels. Metal wheels or laps made of nearly every metal
and alloy in common use, have been more or less employed in the mechanical arts as
vehicles for the application of several of the polishing powders. But of all laps, not-
withstanding their variety, those of lead, slightly alloyed, and supplied wiUi pow-
dered emery, render the most conspicuous service. Generally the plane, or filat surface
LAZULITE. 641
of the lap, is employed ; at other times the cylindrical edge, u hy cutlers ; hut the
portion aotoally used in either case called theyac« of the lap. There are several kinds
of laps. The lap is in some cases a thin disc of metal, fixed hy means of a screwed
nut against a shoulder on the spindle, but it is better with lead laps to employ an iron
plate cast Aill of holes, to support the softer metal. The casting mould may in this
case be either an iron disc, with a central screw to fix the iron centre plate at the
time of poaring, or the mould may be made of sand and in halves, after the usual
manner of the foundry. In either case the iron plate should be made as hot as the
fluid metal, which, by entering the holes, becomes firmly united to the iron, especially
if the holes are largest on the reverse side, or that away from ihe lead. — HoltzapffeL
Zap is also a roll or sliver of cotton for feeding the cards of a spinning machme.
LARD. The fliit of the pig. Our imports from the United States have been
in 1857: —
Cwtf. ConpuCad fmI valoe.
In British vessels - .- 39,207
In Foreign ressels - • 139,188
168,295 £561,684
LARD OIL. Lard being snljected to pressure, an oil, oleinef is expressed, stearme
heing left This lard oil is mach used for lubricating machinery^ and it was employed
for the adulteration of olive oil.
LASKSw All Indian cut stones are called laskM. They are in general ill shaped or
irregular in their form, their depth ill proportioned. The table, or face, seldom in
the centre of the stone, sometimes too broad or too small, and none properly polished.
The chief tiling regarded is saving the size and weight of the stone. These stoaes
are always new wrought when brought to Europe.
LATH WOOD. The outside cuttings of fir trees, used for being split into laths.
LATTEN is a somewhat antiquated term, which was applied to several kinds of
sheet metal ^ Mnes of lattent whatever may have been meant by the word are men-
tioned in the time of Henry VI., who made his chaplain. John Botteright, comp-
troller of all his mines of gold, silver, copper, latten, lead, within the counties of
Devon and Cornwall." Is tin meant by the term ?. — WcUsoiCs Chemical Eaaaift,
In the reigns of Henry VIII. and Edward VI., several acts of parliament were
passed, prohibiting the exportation of brass, copper, latteii, bell metal, gun metal,
schrof metal, &c. Windows framed with lead are called lattiee windows in the West
of England.
The term is now applied to sheet or plate brass. Black latten is rolled sheets;
shaven latten is in thinner sheets, and roll latten is polished on both sides.
LAUNDER. A miner's term for a wooden tube or gutter to convey water. A long
shallow trough carrying off the ore fh>m the stamps.
LAVA. The ejected matter of volcanoes. ^ The stone which flows in a melted
state from a volcano." {LydL) M. Abich obtained from the lava of 1669, 48-88
silica. He made the lava to consist of 54*80 labradoidte^ 84*16 aagite, 7*98 olivine,
and 3*08 magnetic iron.
Bischoff gives Uie following two analyses of lava^ —
Silica ------
Alumina -----
Peroxide of iron - - - -
Lime ------
Magnesia - - - - •
Potash
Soda
LAVA WARE. A peculiar stoneware, manu&ctured and coloured to assume the
semi- vitreous appearance of lava.
LAVER. Porphyra laeiniata and Uloalatissima, (See Alojb.)
LAVENDER, oil of. See Pekfumert.
From the flowers of the Lavandula spicata the oil of spike is obtained, which is used
by painters on porcelain, and by artists in the preparation of some varnishes.
LAWN. A fine linen fabric.
LAZULITE (Eug. and Fr.j Lazulith, Germ.), from an Arabic word, azul, meaning
heaven. It is a blue vitreous mineral, found massive and crystalline, traversing clay
slate, and sometimes united with spathic iron ; spec. grav. 2*76 to 2*94 ; scratches
fflass ; affords a little water by calcination ; fusible into a white glass } dissolves in
Vol. II. T T
Hecla.
Etna.
54-76
-
- 49*63
18*61
-
- 22*47
15*60
.
- 10*80
614
.
- 9-05
1*35
m
- 2*68
8*41
-
- 807
1*21
•
- 0-98
1,
2.
43-88
-
- 46-79
81-77
.
- 27-10
8-90
-
- 7-10
9-89
.
- 11-87
.5-56
.
- 7-12
642 LEAD.
acids with loBS of colour ; the tolstian leares sn alkaline readnam, after bebig treated
with carbonate of ammonia, filtered, evaporated, and calcined. By analysis it is Ibwid
to consist of: ^
Phosphoric acid - . - -
Alumina - - - - .
Protoxide of iron - - - -
Magnesia • - . - -
Water
LEAD. (^Plomb, Fr. ; Blei, Oerm.) This metal appears to have been knovm at
a very early period. It is mentioned by Moses, as a metal in common use. Job
describes minmg for lead, and the metallui^c processes of refining and separatmg
gilver from lead are very clearly described by both Job and Jeremiah. Lad hss a
bluish-grey colour, and, when recently cut, it exhibits considerable lustre, which,
however, it speedily loses. It is one of the softest of the ordinary metals, is easily
cut with a knife, may be scratched with the nail, and marks paper with a grey ftain.
Lead is malleable, and may be beaten into thin leaves, but these are of very imperfect
tenacity ; hence, it cannot be drawn into thin wire ; a wire of f^ of an inch m dia-
meter will not support 20 lbs.
If lead be prepared in a very finely divided state, it is pjfrepkonc. This is usually
prepared from the tartrate of lead, by heating it in a glass tube as long as any fames
are evolved, consequently it is finely divided lead combined with some carbon. As
soon as the fhmes cease the tube must be closed at the blowpipe-lamp. If at any time
the tube is broken, and the powder scattered in the air, it bums wiu a red fladi.
If lead is heated in closed vessels, it fuses at 635^ F. (335^ Cent), and at a red
heat, it gives off vapours. If fused lead is allowed to cool slowly, it crystallises in a
somewhat peculiar manner, the crystals are referrible to the octahedral system, but
they group themselves in a very complicated and interesting way. By the deetio-
chemical action of sine on a solution of the acetate of lead, crystals of that metal are
obtained in an arborescent form. This experiment is usually s'pdcen of as the fonna-
tion of S<Uurn*s tree^ Saturn being the alchemic name for this metaL
When fused in the air, lead oxidises rapidly, and it becomes covered with aa
iridescent pellicle, often of great beauty. It Uien passes into a yellow powder
(Litharge), protoxide of lead.
Pure lead is not affected by perfectly pure water free from air, but if air be present
the metal is oxidised at its expense, and the oxide thus formed, combining with
carbonic acid, is deposited on the lead in minute crystals as a basic carbonate of lead.
The water will then be found to contain lead in solution, and such waters drawn
from impure cisterns often produce very distressing consequences. If the water
contains any sulphates, the lead is thrown down as a sulphate of lead, which is
insoluble.
The native JbmuUUnu are the following. The localities, &C., are mainly derived from
Greg and Lettsom's Manual of the Mineralogy of Great Britain and IrehmdL
1. Native lead. Mr. Greg appears to doubt the existenee of native lead in this
country. He says, however, ** Native lead has been recently discovered in undoubtedly
genuine specimens in the province of Guanaxiuitoin Mexico." Some equally gennine
specimens of native lead have been found in the Grassington mines ; these are in the
possession of the Duke of Devonshire and of Stephen Eddy, Esq.
2. Minitan, Native oxide of lead. This ore is found in Anglesea, at Alston
Moor, the Snailbeach Mine in Shropshire, at Grassington, the Leadhills in Scotland,
and Wicklow in Ireland. Its composition is — lead, 90*66, oxygen, 9 -34.
3. Ceruasite, Carbonate of lead This ore occurs in crystals, in fibrous, compact,
and earthy masses. It is found at several of the lead mines of Cornwall and Devon-
shire, and indeed in nearly all the mines producing the ores of lead, varying mneh in
its character with the different conditions under which it has been formed.
This ore, in its purest state, is colourless and transparent like glass, with an adaman-
tine lustre. It may be recognised by the following characters :
Its specific ^vity is fh>m 6 to 6*7 ; it dissolves with more or less ease, and with
effervescence, in nitric acid; becomes immediately black by the action of sulphuretted
hydrogen, and melts on charcoal before the blowpipe into a button of lead. Accord-
ing toXlaproth, the carbonate of LeadhiUs contains 82 parts of oxide of lead, and 16
of carbonic acid, in 98 parts. This mineral is tender, scarcely scratches calc-spar,
and breaks easily with a waved conchoidal fracture. It possesses the double refhicting
property in a very high degree -, the double image being vcrv visible on looking
through th6 flat faces of the prismatic crystals. Its crystalline forms are very nume-
nms, and are referrible to the rhombohedron.
4. Anglesite, Sulphate of lead, or Vitreous lead, —This mineral closely resembles car-
LEAD. 643
bonate of lead ; lo that the external characters are inadequate to diatingnish the two.
But the fbllowuig are aofficient When pure, it has the same transparency and lustre.
It does not eflFerresoe with nitric acid ; it is bnt feehly blackened bj sulphuretted
hydrogen ; it first decrepitates and then melts before the blowpipe into a transparent
glass, which becomes milky as it cools. By the combined action of heat and char-
coal, it passes first into a red pulverulent oxide, and then into metallic lead. It consists,
according to Klaproth, of 71 oxide of lead, 25 sulphuric acid, 2 water, and 1 iron.
The specimen was from An^lesea ; the Wanlockhead mineral is free from iron. The
prevailing form of crystallisation is the rectangular octahedron, whose angles and
edges are variously modified. This mineral was first recognised in Anglesea, hence
its name. It was found in the Channel Islands at Sark mine, and is occasionally met
with in the Leadbills and Wanlockhead in Scotland, at Glemalure in Wicklow, and
at fiallycoms mine, Co. Dublin.
LmdkUUte, SulphtUO'iricarbonaieoflead, — This ore is of a yellowish white colour,
inclining to grey, sometimes yellowish-green, yellow and brown. Its chemical com-
positioois-—
Sulphate of lead 28-7
Carbonate of lead ....-•. 71*0
99-7
5. Pj^romorphtte» Phosphate of had, — This, like all the combinations of lead with
an acid, exhibits no metallic lustre, but a variety of colours. Before the blowpipe,
upon charcoal, it melts into a globule extemallv crystalline, which by a continuance
of the heat, with the addition of iron and boracic acid, affords metallic lead. Its con-
stituents are 80 oxide of lead, 18 phosphoric acid, and 1*6 hydrochloric acid, according
to Klaproth's analysis of the nuneral from Wanlockhead. The constant presence
of chlorine in the various specimens examined is a very remarkable circumstance.
The crystalline forms are derived from an obtuse rhomboid. Phosphate of lead is a
little harder than white lead ; it is easily scratched, and its powder is always grey.
Its specific gravity is 6*9. It has a vitreous lustre, somewhat adamantine. Its lamellar
textare is not very distinct ; its fracture is wavy, and it is easily frangible. The phos-
phoric and arsenic acids being, according to Bl Mitscherlich, isomorphons bodi^, may
replace each other in chemical combinations in every proportion, so that the phosphate
of lead may include any proportion, from the smallest fraction, of arsenic acid, to the
smallest fraction of phosphoric acid, thus graduating indefinitely into arseniate of lead.
The yellowish variety indicates, for the most part, the presence of arsenic acid. It is
found in Cornwall, Devonshire, Yorkshire, and Derbyshire.
6. MimedU, Arseniate of lead. — The name is derived from fufiririis, imitator, the
speciea so nearly resembling pyromorphite. The colour of this ore varies from straw
yellow and wax yellow to brown, reddish-brown, orange, yellow, and red. Before
the blowpipe, on charcoal, it emits arsenical Amies and yields a bead of lead. The
aaaiyns by Dufrenoy gives the following as its composition: —
Arseniate of lead --.---- 84*66
Phosphate of lead 4-60
Chloride of lead 905
At Drygill, in Cumberland, this ore has been met with in sufficient abundance to be
worked to some extent as an ore of lead. The mimetite from this mine was used in
the manufacture of flint glass, to which it gave great brilliancy. Th^ form of the
arseniate of lead, when it is crystallised, is a prism with six faces, of nearly the same
dimensions as that of phosphate of lead. When pure, it is reducible upon charcoal,
before the blowpipe, into metallic lead, with the copious exhalation of arsenical fumes ;
bat only in part, and leaving a crystalline globule, when it contains any phosphate of
lead. The arseniate of lead is tender, friable, sometimes even pulverulent, and of
specific gravity 5*04. That of Johann-Georgenstadt consists, according to Rose, of
oxide of lead, 77*5 ; arsenic acid, 12*5 ; phosphoric acid, 7 '5; and chlorine, 1*6.
7. Galena, Sulpkids ofkad^-^TlM is the most abundant ore of lead $ it may be
indeed regarded as the oi^y commercial ore of any valoe, if we except the carbonates,
which are probably formed by the decomposition of galena. Its prevailing forms are
the cabe and a combination of the cube and octahedron ; lustre metallic, opaque,
colour and streak lead grey. Fracture oonchoidal, bnt difficult to obtain, owing to the
readiness with which it deaves. The localities of galena need not be named here,
as the lead producing districts, of which a list will be presently given, will include
them, and gslena is included in them all. Thomson's analysis of galena gives -r-
Lead 85*13
Iron 0-50
Solphnr .-.------ 18*02
T T 2
644 LEAD.
8. JamuoiiiU is a combination of lead and antimony. It ocean in adcolar erjatals,
or in parallel or diverging groups, and more f^eqoentiy in fibroos masses. It is fonnd
in many places in Cornwall and Devon. Rose's analysis gives the following as its
composition : —
Lead .--•----. 38-71
Iron 2-96
Copper --------- 0-21
Zinc 0-74
Antimony 34-90
Solphnr --------- 25*53
103-05
This mineral may be regarded as a doable sulphide of lead and antimony, acakgou
to the double sulphide of copper and iron.
9. Crom/ordite. Chloride of lead, Horn-lead, or ckbro-carhonate. — This ore has a
pale yellow colour, is reducible to metallic lead by the agency of soda, and it not
altered by the hydrosulphides. Before the blowpipe it melts first into a pale yellow
transparent globule, with salt of phosphorus and oxide of copper, and manifesu the
presence of chlorine. It is fragile, tender, softer than carbonate of lead, and is some-
times almost colourless, with an adamantine lustre. Spec. grav. 6-06. Itt constitiieBts,
according to Berzelius, are, lead, 25*84 ; oxide of lead, 57*07 ; carbonate of lead, 6*25 ^
chlorine, 8 84 j silica, 1'46 ; water, 054, in 100 parts.
10. Plattnerite. Superoxide of lead.
11. Linariie, Cupreous sulphate of lead.
12. Susannite, SulphatO'tricarbonate of lead,
13. Lanarkite. Sutphato-carlnmateoflead,
14. Calcedonite. Cupreous sutphato-carbonate of lead,
15. Vanadinite. VanadiaU of lead,
16. Wulfenite. Tungstate of lead.
17. StolziU, MolyhdaUoflead.
1 8. wGeocronite, Sulphide of lead and anUmonp
19. Mendipite, an Oxychloride of lead.
20. Matlockite, ditto,
21. Bed lead, or Chromateoflead.-^T]uB mineral is too rare to require oonsideratian
in the present work.
22. Phmb Vauquelinite. CSiromaie of lead and copper.
The ores of lead, which may be represented by galena, or the sulphide of lead,
that being the truly commercial variety, are found in rocks of different ages from the
granite and clay slates to the triasic formations. In the Devonian slate rocks, in
the neighbourhood of Liskeard in Cornwall are many most productive lead mines.
To the north of Truro is the lead mine Huel Rose, which has from its long celebrity
given its name to the district ; and again to the south of Helstone there nave been
some valuable workings for lead. These formations of lead ore have all been in the
clay slate, ** killas " rocks of Cornwall In Devonshire many most valoahle lead
mines have been worked in similar rocks. In these the celebrated mines of Beer
Alston on the Tamar exist. With a very few exceptions but little lead has been
discovered in the black slates, — the carboniferous series of Devonshire. Some lead
ore has, however, been discovered in the new red sandstone and in the slate rocks im-
mediately adjoining them near Newton St Cyres. To the north of the carbonilierDas
rocks of Devonshire we have a renewal of clay slate rocks, similar in all respects to
those which are found near Liskeard in Cornwall; in these rocks are the once
famous argentiferous lead mines of Combe Martin, f^om which Edward the Black
Prince derived an immense revenue.
The lead mines of the Mendip Hills which were at one time very productive, hot
which are now producing but small quantities of lead ore, are in the mountain lime-
stone formations. Those of Cardiganshire are fbund in clay-slates and gricstooes,
correspondent with or underlying the lowest beds described by Sir R. Morchison ia
his Silurian System. — Smyth,
In Shropshire we have lead ore occurring in the original Silurian rocks, the Lfamdeilo
formation. *' In that lofty and rugged district of Shropshire which lies aroond the
village of Shelve and the Comdon mountains, and which extends west of the Stiper
Stones range into Montgomeryshire*' {Murchison), lead lodes are abundant. In
Derbyshire, in Yorkshire, in Cumberland, Northumberland, and Durhanu the lead
mines prove the most productive in the mountain limestone formations, although there
are some instances in which good lead mines have been worked in the sandstones and
shales. In addition to these, we have the mines in the LeadhiUa and at Wanlock-
L£AD. 645
head, eonsiBdng chiefly of the graywacke slates, in Scotland. Logannre, &c in the
granite districts of Wicklow, Newtonards in County Down, with a few others in
IreUnd, and the lead mines in the Silurian rocks of the Isle of Man. lliese are the
principal districts from which our large supplies of lead ore are obtained.
The extensive lead mines of Mr. &aumoDt, which have for many years produced
about one-fourth of the quantity raised in England, about one-sixth of the produce of
Great Britain, and about one-tenth of that of the whole of Europe, including the
British Isles, are so important, and in many respects so characteristic, that much of
the description of them which appeared in the former edition is retained, as repre-
senting many of the peculiar and important features of lead mining. An extensive
section of this great 1^ mining district is in the Mining Record Office of the Museum
of Practical Geology. This section was executed by Mr. Sopwith, and together with
a series of models explains nearly all the phenomena of mineral reins.
The datum or base line of the AUenheads section is 700 feet above the level of the
sea. The drawing, 16) feet in length, is on a true scale of 100 feet to an inch ; by a
true scale being meant, that the lengths and heights are projected to the scale or pro-
portion, so that a true miniature profile ot the country is given, as well as a correct
reduction of the relative sixe of the various rocks. The extent of country thus shown
is not quite 4 miles, being 3 miles 1,220 yards.
The spectator is supposed to be looking to the north, and the section commences at a
point about half a mile eastward from a place called Kilhope Head, which is con-
spicuoQsIy marked in all English maps, inasmuch as the three counties of Northumber-
land, Durham, and Cumberland here meet in one spot At about three quarters of a
mile from the point of commencement, the section represents the hill called Kilhope
Law ; it is on the boundary line of the counties of Northumberland and Durham, and is
the highest point of land in the last-named county, being 2206 feet above the level of
the sea. But out of the limits of this section, and about 10 miles south-west from Kil-
hope Law, the same strata which are here delineated reach an altitude of 2901 feet above
the sea, and this is the highest elevation attained by the rocks which form the car-
boniferous or mountain limestone of the north of England.
Such being the stratification of the central portion of the narrow part of the island,
of which the coal fields of the Tyne and Wear form the extremity on the east bordering
the German Ocean, for some distance north and south of Newcastle, while a similar
coal field is found at the western extremity near Whitehaven, it may be observed with
reference to these coal fields, that they lie over or upon the mountain limestone forma-
tion. The coal beds so extensively worked in the Newcastle and Dmrham coal mines
or collieries gradually rise to the west, and one by one crop out or basset according to
the unduiatioofl of the country. At length at about 20 miles west of the German Sea,
the lowest of the coal beds crops out, and from beneath it gradually appear the limestone
strata, which continue to rise nearly coincident with the general rise of the country,
until they reach the summit of Cross Fell (2901 feet> This general and very gra-
dual inclination of the strata, a feature of the greatest importance in practical mining,
is clearly and accurately delineated in this section.
In a thickness of about 2000 feet of the alternating beds of sandstone, clay, and
limestone which form the strata of the mining districts of Allendale, Alston, and
Weardale, there is one single stratum of limestone, called the ** great limestone," the
veins in which have produced nearly, if not quite, as much ore as all the other strata
put together. This stratum, delineated on the section, lies at a depth of about 850
feet below the sunmiit of Kilhope Law. Somewhat exceeding 2 miles eastward of
this, at AUenheads, the top of the great limestone is 230 feet from the top of a shaft
called Gin- Hill Shaft Its thickness, which is tolerably uniform over several hundred
square miles of country, is about 60 feet ; and it is in this stratum of limestone that
the largest quantity of lead has been found.
The dislocations of strata which constitute for the most part important mineral
veins, are exhibited more in detail in the series of geological models already re-
ferred to.
At about a quarter of a mile to the west of, or left hand direction from Kilhope
Law, the great limestone, and all other associated beds are thrown down a depth of
about 150 feet for a space of nearly 7t)0 feet ; and again, at the distance of nearly a
mile from AUenheads, a vast dislocation takes place, by which the great limestone
is brought nearly to the surface, the amount of dispiacement being about 4U0 feet.
It^is in the great limestone that by fkr the most extensive portion of the work-
ings of AUenheads lead mines are situated, and the galleries or levels are very
extensive. In a great Sickness of strata above the great Umestone, only two beds
of that rock are found. One of these is called *' Uttle limestone.'' It is fh>m 10 to
12 feet thick, and is 75 feet above the top of the great limestone. The other is still
more inconsiderable, being only 3 or 4 feet thick, and is 440 feet above the great
TT 3
646 LEAD.
limettone. It is remarkable with what ^xactnets this thin bed is finmd near the
summit of hiUs, the intervening spaces haying apparently been remoTed bj deno-
dation, so as to form in one case a gap of 6^ miles, and m another of 1| miles, in
which the Tell Top limestone is entirely cut off.
But beneath the great limetone, are several beds of the same descrip^tioa of rock,
viz. at distances respectively of 30, 106, 190, 250, and 287 feet, and the thickness 2, 24,
10, 15, and 35 feet. These are known by descriptive local names, and oompnae all
that are of significance as regards lead mining operations.
The AUenheads mines being situated for the most part at depths from the sar&ee
varying from 200 to 600 feet are drained, partly by ordinary waterwheela, and paitiy
by hydraulic engines constructed by Mr., now Sir W. G. Armstrong. See Watbb
Pressure Engines.
I Such is a general view of the lead mining districts of England. The following
brief account of foreign lead mines is retained ftx>m the Ust edition. Much additiooal
information will be found in the article Mines.
The principal lead mines at present worked in other parts of the world are the
following : — 1. Poollaonen and Huelgoet, near Carhair in France, department
Finisterre, being veins of galena, which traverse a clay slate resting on granite. They
have been known for upwards of three centuries ; the workings penetrate to a
depth of upwards of 300 yards, and in 1816, furnished 500 tons of lead per annnm,
out of which 1034 pounds avoidupois of silver were extracted. 2. At Villefort and
Yiallay, department of Lozdre, are galena mines said to produce 100 tons of kad
per annum, 400 kilogrammes of silver (880 lbs. avoird.). 3. At Peaey and MaooC, to
the east of Moutiers in Savoy, a galena mine exists in talc-schist, which has produced
annually 200 tons of lead, and about 600 kilogrammes of silver (1230 lbs. aToinLj.
4. The mine of Vedrin near Namur in the Low Countries, is opened upon a von of
galena, traversing compact limestone of a transition district ; it has i^Lmisbed 200
tons of lead, from which 385 pounds avoirdupois of silver were extracted. 5. In
Saxony Uie galena mines are so rich in silver as to make the lead almost overlooked.
They are enumerated under silver ores. 6. The lead mines of the Harz have been
likewise considered as silver ones. 7. Those of Blcyberg in the Eifel, are in the
same predicament 8. The galena mines of Bleyberg and Villach in Carinthia, in
compact limestone. 9. In Bohemia to the south-west of Prague. IOl Minea of
Joachimstbal and Bleistadt on the southern slope of the Erzgebirge, produce argenti-
ferous galena. 11. There are numerous lead mines in Spain, the most important
being in the granite hills of Linares, upon the southern slope of the Sierra Morena,
and in the district of the small town of Gai\Jagar. Sometimes enormous masses of
galena are extracted from the mines of Linar^. There are also mines of galena in
Catalonia, Grenada, Murcia, and Almeira, the ore of the last locality being generally
poor in silver. 12. The lead mines of Sweden are very argentiferous* and worked
chiefly with a view to the silver. 13. The lead mines of Daouria are numerous and
rich, lying in a transition limestone, which rests on primitive rocks ; their lead is
neglected on account of the silver.
There have been a few lead mines in this country, which have been equally pro-
ductive of silver. This was especially the case with the lead mines which were
formerly worked around Combe Martin, and those at Beer-Alston in Devonshins.
One of the most remarkable of recent examples, is a small mine known as Hnel
Florence near Tavistock, from which some lead ore has been sold at upwards of 96l
a ton, on account of the large quantity of silver it contained. At the oondnsioo of
this article some tables will be given, showing the argentiferous character of the dif-
ferent lead producing districts of the United Kingdom.
Before proceeding to the consideration of the metallurgy of lead, a few brief noCioes
of the history of lead mining may not be out of place.
As we have already stated, mining for lead must have been one of the earliest of
man's subterranean laoours, and at all periods of history we learn that lead mines
have been worked. The Romans, especially, worked lead mines in Spain, and, after
the conquest of this country, in many of our lead producing districts, especially in
Cardiganshire, Shropshire, and Flintshire.
Lead mining appears to have been carried on from a very early period in Alston
Moor, and some other of the northern districts. But in the west of England, lead
mining must be regarded as a somewhat recent industry.
" Borlase mentions, in 1758, that lead mines had anciently and lately been worked
in Cornwall, and that those most noted formerlv, were Penrose, Penwerty, Trevasens,
Beiestian, and Guarnek (Garras). He states, that Penrose mines (near Uelstone) had
been wrought for about 200 years, that is, from about the middle of the sixteenth
century', and that they had yielded tolerable profit within thirty years. The only
lead mine worthy of note at work in his time, was at St. Issy, near Padstow. Pryce*
LEAD. • 647
dcKiibet the lead ore of Gams, near Tmro, to have been ao argentiferooa, tliat when
wTCNigltt aboat 1720, it prodaeed 100 ox. of silrer in the ton of lead. Hael Pool,
near Helstone, about 1790, yielded fh>m 40 to 50 oa. of aiWer per ton of lead, and
works were ereeted for extracting the BiWer. The lead ore of ^eal Rote eontained
60 OS. of tiller per ton.
In Devonshire, the Combe Martin and Beer Alston mines, haye long been eele*
Ivrated for their argentiferous lead ores. It is stated, that the produce of these mines
was unusually great in the reigns of Edward I. and Edward II. In 1293, William
de Wymnndham accounted at the Treasury for 270 lbs. of silyer raised in Deron.
In 1294, it amounted to 521/. 10«. weight ; and in 1294, to 704/. Ss. Id. weight. In
1296, great profit is stated to haye beoi derired from the Deron mines ; and 360
miners were impressed out of Derbyshire and Wales to work in them. In 1860, a writ
was issued, authorising certain persons to take up as many miners and workmen as
should be necessary to work in the king's mines in Devon, allowing them reasonable
wajpes according to the custom of the country ; to arrest and imprison such as should
resist, till the^ uiould give security to senre the king in the said mines, and to buy
and provide tmiber at a competent price.
Henry, bishop of Winchester and cardinal of England, as one of the executors of
John, duke of Bedford, who had a grant fnm the king of the gold and silver mines
of Devon and ComwaU, rendered 26 lbs. and 2 ox. weight of pure silver as the 15th
part of the pure silver raised in th()se counties from 15th December, 2l8t, to 16th
August, 23rd of the same king's reign.
The Combe Martin mines were re-opened in the reign of Elizabeth. The working
of these mines was strongly recommended to the I^ng Pariiaroent in 1659 ; but
Lysons observes that they do not appear to have been again worked until the close of
that century, and then without success. In 1813 they were again opened and worked
for 4 years, producing only 208 tons of ore in that time. In 1887 they were again
worked, and we had an opportunity of observing that the previous mining operations
presented every appearance of having formerly been very unskilfully managed. The
two lodes near B<Ner- Alston hare produced large qoantities of argentiferous galena,
often containing from 80 to 120 oz. of silver per ton of lead. Aceordine to Mr.
Hitchings, the greatest qaantity which occnrred in that part of them named the South
Hooe mine was 140 oz. of silver per ton of lead. In 1784 and 1785 the silver pro*
dace of these mines amounted to 6500 oz. From Huel Betsy, near Tavistock, which
was re-opened in 1806, fh»m 800 to 400 tons of lead, and from 4000 to 5000 oz. of
silver were annually obtained. Lead mines were worked at a very early period in the
Isle of Man, but the recent workings only date from the commencement of the present
century. The mines of Cardiganshire were evidentiy worked by the Romans. In
the reigns of Henry VII. and of Elizabeth thej attracted mnch attention, and Gkrman
miners were invited to work them.
The English lead-miners distinguish three different kinds of deposits of lead ore ;
rake^reiiu, pipe^veing, tjid Jiat-tfetM, The English word vein corresponds to the
French term JUon; but miners make use of it indifferently in England and France, to
indicate all the deposits of this ore, adding an epithet to distinguish the different forms ;
thns, rakt'VexM are tme veins in the geoloipeal acceptation of the word vein ; pipe-
veins are masses usually very narrow, and of oblong shape, most frequentiy parallel to
the plane of the rocky strata ; taidJlai'Veint are small beds of ores interposed in the
middle of these strata.
In the north of England, which, on account of its great preponderance in produce,
we take as the basis of oar description of lead mining, the ores are for the most part
found in veins (lodes in Cornish) and flats. AHbough different names have been as-
signed to occasional varieties, the usual occurrence of lead ore is in rake veins, or
direct running veins, usually named as veins, with some distinctire appellation pre-
fixed, as, for example, RampgiU Vein, Hodgillbam Vein. Other veins, lying parallel,
receive a similar prefix, with the addition of the words north, east, or south ; but for
the last named the word sun is often used ; as, for instance, Hudgillburn Sun Vein,
and 2nd and 3rd Sun Vein if further discoveries are made of otiier parallel veins.
Considerable quantities of ore are also raised from horizontal extensions of portions
of the vein called^ato, and these are interposed between the strata adjacent to tiie vein.
JRake veins are the most common form in which lead ore occurs in Cumberland.
They are in general narrower in the sandstone which corers the limestone, than in the
calcareous b^. A thickness of less than a foot in the former becomes suddenly 3 or
4 feet in the latter ; in tiie rich vein of Hudgtllbum, the thickness is 1 7 fieet in the
Great limestone, while it does not exceed 8 feet in the oyerlyingWatersiU or sandstone.
This influence exercised on the veins by the nature of the enclosing rock, is instruc-
tive ; it determines at the same time almost uniformly their richness in lead ore, an
observation nmilar to what has been made in other countries, especially in the veins
TT 4
648 . LEAD.
of Kongsberg ia Norway. The Cmnberland Teins are eonstantly richer, the
powerful they are, in the portions which traverse the calcareous rocks, than in the beds
of sandstone, and more particularly the schistose rocks. It is rare in the rock called
plate (a solid slaty clay) for the vein to include any ore ; it is commonly filled with a
species of potter's earth. The upper calcareous beds are also in general more prodne-
tiTe than the lower ones. In most of these mines, the veins were not worked till
lately below the fifth calcareous bed (the four-fathom limestone^, which is 307 yards
beneath the millstone-grit ; and as the first limestone stratum is 108 yards beneath
it, it follows that the thickness of the part of the ground where the yeins are rich m
lead does not in ^neral exceed 200 yards. It appears however that Teins have been
mined in the neighbourhood of Alston Moor, downwards to the eleventh calcareoos
stratum, or Tyne bottom limestone, which is 418 yards under the millstone-grit of ihe
coal formation, immediately above the whin-sill ; and that they have been followed
above the first limestone stratum, as high as the grindstone sill, which is only 83 yards
below the same stratum of millstone -grit; so that in the total thickness of the plumbi-
ferous formation is there more than 336 yards. It has been asserted that IcmI veins
have been traced even further down, into the Memerby scar limestone ; but they have
not been mined.
The greatest enrichment of a vein takes place commonly in the points where its
two sides, being not far asunder, belong to the same rock ; and its impoverishment
occurs when one side is calcareous and the other a schistose clay. The minerals which
most frequently accompany the galena, are carbonate of lime, fluate of lime, snlphate
of baryta, quartz, and pyrites.
The pipe veins (anuu in French), are seldom of great length ; but some have a
considerable width; their composition being somewhat similar to that of the rake veins.
They meet commonly in the neighbourhood of the two systems, sometimes being in
evident communication together ; they are occasionally banren ; but when a wide pipe-
vein is metalliferous, it is said to be very productive.
The JlcU veins, or strata veins, seem to be nothing else than expansions of the matter
of the vein between the planes of the strata ; and contain the same ores as the veins
in their vicinity. When they are metalliferous, they are worked along with the ad-
jacent rake vem ; and are productive to only a certain distance from that vein, onleai
they get enriched by crossing a rake vein. Some examples have been adduced of ad-
vantageous workings in Jlat veins in the great limestone of Cumberland, particnlariy in
the mines of Coalcleugh and Nenthead. The rake veins, however, furnish the greater
part of the lead which Cumberland and the a^acent counties send every year into
the market
The metalliferous limestone occupies, in Derbyshire, a length of about 25 miles from
north-west to south-east, under a very variable breadth, which towards the south
amounts to 25 miles. Castleton to the north, Buxton to the north-west, and Matlock
to the south-east, lie nearly upon its limits. It is surrounded on almost all sides by
the millstone grit which covers it, and which is, in its turn, covered by the coal stratL
The nature of the rocks beneath the limestone is not known. In Cumberland the
metalliferous limestone includes a bed of trap, designated under the name of whined
In Derbyshire the trap is much more abundant, and it is thrice interposed between the
limestone. These two rocks constitute of themselves the whole mineral mass, throogh
a thickness of about 550 yards, measuring from the millstone grit; only in the nfper
portion, that is near the millstone grit, there is a pretty considerable thickness of
argillo-calcareous schists.
Four great bodies or beds of limestone are disting^hable, which alternate with
three masses of trap, called toadstone. The lead veins exist in the calcareous strata,
but disappear at the limits of the toadstone. It has, however, been ascertained that
they recur in the limestone underneath. See Yein8.
Metaixurot ot Leai>.
Although lead forms an essential element in a large number of minerals, the ores of
this metal are, strictly speaking, far from numerous. Of these the most important is
sulphide of lead, or galena. This mineral, which possesses a metallic brilliancy, and
has a lighter colour than metallic lead, presents, in its cleavage, all the variations
from large facettes and lamine indicating a cubic crystallisation to a most minutely
p^ranular structure. It is extremely brittle, and its powder presents a brilliant black-
ish-grey appearance.
The specific gravity of galena is 7'5 to 7*8, and its composition, when absolutely
pure, is : —
Lead 86*55
Sulphur .....••- 18'45
100-00
LEAD. 649
Galena is, however, but seldom found chemically pure, as, in addition to variable
?nantities of earthj impurities, it almost always contains a certain amount of silver,
t is usually observed that galena presenting large facettes is less argentiferous than
those varieties having a closer grain, and that finely granular steely specimens gene-
rally afiFbrd the largest amount of silver.
It would appear, from recent experiments, that the silver contained in the finely-
firanular varieties of galena often occurs in the form of sulphide of silver, mechanically
intermixed, whilst in the more flaky descriptions of this ore, the sulphides of lead
and silver are chemically combined.
Galena occurs in beds and veins, in granite, gneiss, clay-slate, limestone, and sand-
stone rocks.
In Spain it is found in the granite hills of Lanar^s and elsewhere; at Freiberg in
Saxony it occupies veins in gneiss ; in the Harz, Bohemia, Cornwall, and many other
localities, it is found in killas, or clay-slate. The rich deposits of Derbyshire, Cum-
berland, and the northern districts of England, are in the mountain limestone, whilst
at Conmiem, near Aix-la-Chapelle, large quantities of this ore are found disseminated
in the Bunter sandstone.
This mineral is frequently associated with blende, iron and copper pyrites, the car-
bonate and other ores of lead, and usually occurs in a gangne of sulphate of baryta,
calc-spar, spathose iron, or quartz. It is also not unfrequently associated with fluor-
spar.
The next most important ore of lead is the carbonate, which is a brittle mineral, of
a white or greyish- white colour, having a specific gravity varying from 6 '4 6 to 6*50.
Its composition is, —
Carbonic acid ....... 16*05
Oxide of lead 83*56
99-61
Large quantities of this substance occur in the mines of the Mississippi Valley in
the United States of America, where they were formerly thrown away as useless, but
have since been collected and smelted. Vast deposits of this substance have also been
found in the Bunter sandstone, near Diiren, in Prussia, and at Freyung, in Bavaria.
In the two latter localities ft appears to form the cement holding together the granules
of quartz, of which the sandstone principally consists. These ores, which yield from
14 to 20 per cent of metal, do not readUy ailmit of being concentrated by washing.
The sulphate of lead does not often occur in suflBicient quantities to be employed as
an ore of that metal. In appearance it is not unlike the carbonate, but may readily
be distinguished frx>m it by its not dissolving with efiervescence in nitric acid.
Its specific gravity is from 6*S5 to 6*30, and its composition : —
Sulphuric acid 25*65
Oxide of lead 74*05
99*70
This ore of lead usually results frt>m the oxidation of galena. At St. Martin's,
near Uie Vega de Bibaddeo, in Spain, this mineral, more or less mixed with the
phosphate of lead, is found in sufficient quantities to be made, on a small scale, the
subject of an especial metallurgic treatment Large quantities of sulphate of lead ores
are also annually imported into this country from Uie mines in Australia. These
ores contain on an average 35 per cent of lead, and 35 oz. of silver to the ton of ore,
together with a little gold.
Phosphate of lead, when crystallised, usually presents the appearance of hexagonal
prisms, of a bright-green, brown, or yellowish colour. Its specific gravity varies from
6*5 to 7*1. This mineral is composed of a mixture of true phosphate of lead, phos-
phate of lime, chloride of lead, and fluoride of calcium, and usually contains about
78 per cent, of oxide of lead. In Spain, it occurs in botryoidal forms, in connection
with the sulphate of the same meta^ and is treated in blast furnaces for the lead it
affords.
The other minerals containing lead seldom occur in sufficient quantities to be of
much importance to the smelter, and may therefore be disregarded in Uie present article.
The extraction and mechanical preparation of ores is the business of the miner,
and not of the metallurgist who receives them from the former f^ed as perfectly as
possible from foreign matters.
The metallurgic processes, by the aid of which lead is obtained from galena, may
be divided into two classes. The first of these is founded on the following reactions ; —
If one equivalent of sulphide of lead and two equivalents of the oxide of the same
650 LEAD.
metal ne ftued together, the result ii three eqaiTale&tf of metaUie lead and oae
equiralent of solphuroas acid, which is evoWed.
This reaction is represented hy the following equation :—
Pb8 + 2PbO-3Pb+SO«
When, on the other hand, one equivalent of solphide of lead, and one equralent of
sulphate of lead are similarly treated, two equivalents of lead are obtained, and two
equivalents of sulphurous acid gas evolved. Thus : —
PbS + PbO,SO»« 2Pb + 280*.
The process, founded on the foregoing reactions, and which we will distinguish as
the method by double decomposition^ consists in roasting the galena in a reverbentory
furnace until a certain amount of oxide and sulphate has been formed, and snbee-
quenUy, after having intimately mixed the charge, and dosed the doors of the funiaee,
causing the whole to enter into a state of fusion.
Daring this second stage of the operation, the reaction between the sulphides, sul-
phates, and oxides takes place, and metallic lead is eliminated. The roasting of the
ore is, in some cases, conducted in the same furnace in which the fusion is effected,
whilst in others two separate furnaces are employed.
The process by double decomposition is best adapted for the richer varieties of ore,
and such as are least contaminated by siliceous or earthy impurities, and is cod-
sequently that which is almost universally employed for smelting the ores of this
country.
By Uie second method which we will call the procese by affimfy, the ore is fhsed
with a mixture of metallic iron, which by combining with the sulj^nr liberates the
metallic lead. This reaction will be understood by reference to the ioUowiog for-
mula:—
PbS + Fe«Pb+FeS.
In practice, however, metallic iron is not always employed for this purpose ; cast-
iron is also frequently used, and in some instances the ores of iron and hammer slags
are substituted, as are also tap-cinder and other secondary products containing a con-
siderable percentage of this metaL None of these substances are, however, round to
be so efficacious as metallic iron, since cast-iron requires to be decarburised before it
can readily decompose the sulphide of lead, and the ores of iron require the intro-
duction of various fluxes, and the consequent expenditure of an additional amount of
fueL In all cases, however, it is judicious to subject the ore to a preliminary roasting,
in order to eliminate a portion of the sulphur, and thereby reduce the expenditure of
iron, as well as to agglutinate the ore and render it better adapted for its subsequent
treatment in the blast furnace.
We will not attempt to describe the different forms given to roasting fnmaoes em-
ployed for the ores treated by this process, but would remark that they fl^uently
resemble the kilns used for the preparation of lime, whilst in some instances the ores
are roasted in heaps interstratified with wood or other fdel.
The method of treating ore by affinity is particalarly adapted to those rarieUes that
contain a considerable amount of silica, since such minerals, if treated by double de-
composition, would, by the formation of oxide of lead, give rise to silicates, from
which it would be exceedingly difficult to extract the metal.
Engiieh procese. Treatment by double decomposition, — Galena, if placed m a
close vessel which protects it from the action of the air, and exposed to a gra-
dually increasing temperature, becomes fused without the elimination of any lead
taking place, but ultimately a portion of the sulphur is driven off; and a snbsolphide
is formed, which at a very elevated temperature is volatilised without change.
If, however^the vessel be uncovered, and the air allowed to act on its contents,
oxygen combines with the sulphur, sulphurous acid is evolved, and the desnlphnrmtioa
of the mineral is slowly effected.
When galena is spread on the hearth of a reverberatory fVimace, and is so plaeed
as to present the largest possible amount of surihce to oxidising infiuenoes, it will be
found that the surface slowly becomes covered with a yellowish-white cnist of sulphate
of lead. The oxygen of the air, by combining with the two elementary bodies of
which gaUna is composed, will evidently produce this effect This is not, however,
the only chemical change which takes place in the charge under these cirenmstanoes ;
oxide of lead is produced at the same time as the sulphate, or rather the fonnatioa of
the oxide is prior to that of the sulphate.
In fiict, daring the first stage of the operation of roasting, snlphnrovs acid is
evolved, the sulphur quits the lead, and a portion of that metal renuuns in a free
state. This becomes oxidised 1
qoently a part of it ocsnbines wi
bv the air passing through the fumaoe, and subse-
ith sulphuric acid, formed by the oixidatioii of su'phu-
LEAD. 651
roos acid, and sulphate of lead is the result. In this way, after the expiration of a
certain period, both oxide and sulphate of lead are present in the ftimace.
During the early period of the roasting, when the temperature of the furnace is not
T«%ry elevated, the proportion of sulphate is larger than that of the oxide formed, but
in proportion as the heat of the apparatus increases, Uie production of oxide becomes
more considerable, whilst that of the sulphate diminishes.
The sulphate and oxide thus formed re-act in their turn on the nndecompo«ed
g^alena, whilst a portion of the latter, by combining wiUi the sulphide of lead, gives
rise to the formation of oxysulphide.
This last compound has no aetion on galena, except to dissolve it in certain pro-
portions, but is readily decomposed by the aid of carbonaceous matter.
It is therefore evident that the addition of carbon, at this stage of the operation,
will have the effect of reducing Uie oxide and oxysulphide of lead.
Every process then that has for its object the reduction of lead ores by double
decomposition, comprises two principal operations. Ist. The reduction of galena, by
the aid of heat and atmospheric air, to a mixture of sulphide, oxide, and sulphate,
which mutually decompose each other, with the elimination of metallic lead. 2nd.
The reduction of the oxysulphide ^ the addition of carbonaceous matter.
The reverberatory furnace* — The reverberatory furnace employed for the
treatment of galena is composed, like all other furnaces of this debcription, of three
distinct parts, the fire-place, the hearth, and the chimney.
The hearth has to a certain extent the form of a funnel, of which the lowest point
is on the front side of the furnace immediately below the middle door. The molten
metal descending from every side along the inclined bottom or sole, is collected in
this receptacle, and is ultimately run off by means of a proper tap-hole. This tap-
hole is, during the operation, closed by a pellet of clay.
The inclination of the hearth is more rapid in the vicinity of the fire-bridge than
towards the chimney, in order that the liquid metal may not be too long exposed to
the oxidising and volatilising influences of a current of strongly-heated air.
The dimensions given to these furnaces, as well as the weight of the charge
operated on at one time, vary considerably in different localities, but in the north of
England the following measurements are usually employed :— The fire-grate is 6 ft.
9 in. X 1 ft. 10 in., and the thicJ^ness of the fire-bridge 1 ft 6 in.; the length of the
sole is 9 ft, and its averace width 7 ft The depth of the tap is about S ft 6 in. below
the top of the inclined sole. The height of the roof at Uie fire-end may be 1 ft. 4 in.,
and at the other extremity 11 inches.
The introduction of the charge is in some cases effected by the doors of the furnace,
whilst in other instances a hopper, placed over the centre of the arch, is made use of.
On the two sides of the fiurnace are placed three doors about 11 in. x 9 in.,
which are distinguished as 1, 2 and S, counting from the fire-bridge end. The three
doors on the one side are known as the front-doors, whilst those on the other side are
called the back-doors. Immediately beneath the door on the fhmt side of the furnace
is situated the iron pan into which the molten lead is tapped off.
The bottom of this arrangement is in most cases composed of fire-bricks, covered
by a layer of vitrified slags, of greater or less thickness. In order to form this bottom,
the slags are introduced into the furnace, the doors closed, and the damper raised.
An elevated temperature is thus quickly obtained, and as soon as the scorios have
become sufficiently fused, they are, by means of rakes and paddles, made to assume
the required form. The charge employed, as before stated, varies in almost every
establishment. In the North, however, smaller charges are used than most other
localities. At Newcastle, and in the neighbourhood, the charge varies fVom 12 to 14
cwt.; in Wales, and near Bristol, 21 cwt charges are treated; whilst in Cornwall,
charges of 30 cwt are not unfrequently worked. The time required for smelting a
charge varies with its weight and the nature of the ores, f^om 6 to 24 hours.
In some cases the ore is introduced raw into the fiimace, whilst in others it under-
goes a preliminary roasting previous to its introduction. Rich ores are generally
smelted without being first calcined, but the poorer varieties, and particnlarly those
which contain large quantities of iron pyrites, are, in most instances, sulqected to
roosting in a separate fhmace.
In order to understand more clearly the operation of smelting in furnaces of this
description, we will suppose that a charge has just been tapped off, and that, after
thoroughly clearing the hearth, a f^h charge of raw ores has been introduced. Du-
ring the first part of the operation of roasting, which usually occupies about two
hours, the doors are taken off to admit free access of air, and also for the purpose of
cooling the furnace, which has been strongly heated at the close of the preceding
operation. No fuel is at this period churged upon the grate, since the heat of the
furnace is of itself sufficient to effect the elimination of the fint portions of sulphur.
652 LEAD,
Tbe ore is carefaUy stirred, for the purpose of constantly presenting a fresh snriaee
to oxidising inflaences, and when -white fames are no longer observed to pass off in
large quantities, a little coal may be thrown on the grate, and the temperature grada-
ally elevated nntil the diarge becomes slightly clammy and adheres to the rake.
When the roasting is considered as being sufficiently advanced, the smelter turns his
attention to the state of the fire, taking care to remove the clinkers and get tbe grate
into proper condition for the reception of a fresh supply of fheL The furnace doors
are now closed, and a strong heat is kept up for about a quarter of an hour, when the
smelter examines the condition of his charge by removing one of the doors. If the
operation is progressing satisfactorily, and the lead flowing freely and passing without
obstruction into the tap, the firing is continued a little longer ; but when the ores
have been found to have taken fire, or are lying unevenly on the bottom of the fnr>
nace, the position of the charge is changed by the use of an iron paddle. During
this operation the fhmace becomes partially cooled, and the reduction of temperature
thus obtained is frequently found to produce decompositions, which facilitate tbe re-
duction of the charge. In the case of extremely refractory ores this alternate heating
and cooling of the furnace is sometimes almost indispensable, whilst, in other in-
stances, their being once or twice raked over is all the manipulation that is required.
We will suppose that four hours have now elapsed since the charging of the fhr-
nace, and that the charge has run down the inclined sole towards the tap. The
smelter now examines the condition of the scorise and adds a couple of shovelfnls of
lime and three or four ^ovelfuls of small coals, the amount and relatire proportions
of these being regulated in accordance with the aspect of the slags. The charge is
now, by means of proper tools, agun raised to the breast of the furnace, and the firing
continued until the charge has run down into the tap hole. The foreman now takts
his rake and feels if any lumps remain in an unfused condition, and if he finds all to
be in a fluid state he calls his assistant from the other side, and by the addition of a
small (Quantity of lime and fine coal, makes the slag assume a pasty or rather doughy
consistency. By the aid of his paddle he now pushes this compound up to tbe oppo-
site side of the furnace, where it is drawn by an assistant through the back door into
a trough containing water. Whilst the assistant is doing this the foreman is busily
engaged in tapping ofi^ the metal into the iron pan in front of the furnace, from which,
when sufficiently cooled, it is laded out into suitable moulds.
The total duration of the operation may be about six hours.
To build a furnace of the above description, 5000 common bricks, 2000 fire bricks,
and 2^ tons of fire-day are re(|uired. In addition to this must be reckoned the iron-
work, the expense of which will be much infinenced by the nature of the armatures
employed and the locality in which the furnace is constructed.
The amount of fuel employed for the treatment of a ton of lead ore varies not only
in relation to the richness of the mineral, but is also much infinenced by the nature ci
the associated matrix and the calorific value of the fuel itself. The loss of metal ex-
perienced during the operation is mainly dependent on the richness of tbe ore treated
and tbe skill and attention of the foreman.
In the North about 12 cwt of coal are consumed in the elaboration of one too of
ore, and the loss of metal on 60 per cent, ore may be estimated at about 12 per cent,
of which about 6^ per cent is subsequently recoTcred from the slag and fumes: At a
well-conducted smelting works, situated in the west of England, in which the arerage
assay of the ores smelted during the year was 75|, the yield from the smelting fur-
naces was 68^ per cent, and the coal used per ton of ore was IS| cwts. Tbe lead
recovered fVom the slag and fiimes amounted to 2} per cent, makmg tbe total yield
of metal 71^ per cent, and the loss on the assay produce 4| per cent
In this establishment the men are paid from fa. %d. to 12«. 6d per ton of lead, in
accordance with the nature of the ores operated on.
In one establishment the process before described is somewhat varied. Tbe charge
employed is 21 cwt. This is run down and tapped off at the expiration of 6 hours,
and about 9 pigs of 1^ cwt each usually obtained. A second charge of 21 cwt is
then dropped in, and, as soon as it is roasted, mixed with the slags of the former ope-
ration. The whole is then run down in the ordinary way, the slags drawn and the
lead tapped off in 9 hours. The produce of the second or double charge is from 14
to 15 pigs.
If the ores ai:e difficult to flow, 16 to 16^ hours are required for the two charges.
A small quantity of bUtck slag from the slag hearth is employed for drying up.
Figg. 1079, 1080, 1081, represent the reverberatory furnace at the Marquess of West-
minster's lead smelting works, two miles from Holywell. The hearth is hollowed out
below the middle door of the furnace ; it slopes from the back and ends towards this
basin. The distance from the lowest point of this concafvity up to the sill of tbe door,
is usually 24 inches, but it is sometimes a little less, according to tbe quality of the
LEAD.
658
ores to lie nnelted. This fhrnace has no hole for ranning off the slag, aboye the lerel
of the tap hole for the lead, like the smelting farnace of Lea, near .Matlock. A
single chimney stalk senres for all the establishment; and receives all the fines of the
TanoQS roasting and reducing fhmaces. J^t^. 1081 gives an idea of the distribution of
these fines, a a a, &c. are the furnaces ; 6, the flues, 18 inches square ; these lead
from each furnace to the principal conduit c, irhich is five feet deep bj 2^ wide; d is
6 feet deep by 3 wide; e is a round chamber 15 feet in diameter ; /is a conduit, 7 feet
high by 5 wide ; g another, 6 feet high by S wide. The chimney at A has a diameter
at bottom of SO feet, at top of 12 feet, including the thickness of its sides, forming a
truncated cone 100 feet high ; whose base stands upon a hill a little way from the
furnaces, and 62 feet above their level.
a, flgs. 1079, 1080, is the grate ; 6, the door of the fire*place ; c, the fire-bridge ; d, the
arched roof; s, the hearth ; ///, &c. the working doors ; g g, fines running into one
1079
1081
conduit, which leads to the subterranean condensing-chamber e, and thence to the
general chimney ; A, a hopper-shaped opening in the top of the furnace, for supplying
it with ores.
This magnificent structure is not destined solely for the reduction of the ores, but
also for dissipating all the vapours which might prove noxious to the health of the
workpeople and to vegetation.
The ores smelted at Holywell are very refiractory galenas, mixed with blende, cala-
mine, pyrites, carbonate of lime, &c., but without an^ fiuate of lime. They serve
mutually as finxes to one another. The coal is of inferior quality. The sole of each
furnace is formed of slags obtained in the smelting, and they are all of one kind. In
constructing it, 7 or 8 tons of these slags are first thrown upon the brick area of the
hearth ; are made to melt by a brisk &e^ and in their stiffening state, as they cool,
they permit the bottom to be sloped and hollowed into the desired shape. Four
workmen, two at each side of the furnace, perform this task.
The ordinary charge of ore for one smelting operation is 20 cwt, and it is intro-
duced through the hopper. An assistant placed at the back doors spreads it equallv
over the whole hearth with a rake ; the furnace being meanwhile heated only with
the declining fire of a preceding operation. No regular fire is made during the first
two hours, but a gentle heat merely is kept up by throwing one or two shovelfuls of
small coal upon the grate from time to time. All the doors are closed, and the re-
gister-plate of the chimney lowered.
The outer basin in front of the fhmace is at this time filled with the lead derived
from a former process, the metal being covered with slags. A rectangular slit above
the tap hole is left open, and remains so during the whole time of the operation, unless
the lead should rise in the interior basin above the level of that orifice; in which case
a little mound must be raised before it
The two doors in front furthest fh>m the fire being soon opened, the head-smelter
throws in through them, upon the sole of the furnace, the slags swimming upon the
654 LEAD.
bath of lead, and a little while afterwards he opens the tap-hole, and nms off the
tallic lead reduced from these slags. At the same time his assistant turns o^er the ore
with his paddle, through the back doors. These being again closed, while the aboTe
two front doors are open, the smelter throws a shovelful of small coal or coke cinder
npon the lead bath, and works the whole together, turning over the ore with the paddle
or iron oar. About three quarters of an hour after the commencement of the opera-
tion, he throws back npon the sole of the hearth the ftesh slags which then float upon
the bath of the outer basin, and which are mixed with coaly matter. He next turns
over these slags, as well as the ore with the paddle, and shuts all the doors. At this
time the smelter lades off the lead into the pig- moulds.
The assistant now turns over the ore once more through the back doors. A little
more than an hour after the operation began, a quantity of lead proceeding ftom the
slag last remelted, is run off by Ae tap; being usually in such quantity as to fill one
half of the outer basin. Both the workmen then turn over the ore with the paddles,
at the several doors of the fUmace. Its interior is at this time of a dull red heat; the
roasting being carried on rather by the combustion of the sulphurous ingredients, than
by the action of the small quantity of coal in the grate. The smelter, after shutting
the front doors, with the exception of that next the fire-bridge, lifts off the fresh slags
lying upon the surfieice of the outside bath, drains them, and throws them back into
the furnace.
An hour and a half after the commencement, the lead begins to ooxe out in small
quantities from the ore ; but little should be suffered to fiow before two hours have
expired. About this time the two workmen open all the doors, and turn over the ore,
each at his own side of the fiimace. An hour and three quarters after the beginning,
there are few vapours in the furnace, its temperature being very moderate. No more
lead is then seen to fiow upon the sloping hearth. A little coal being thrown into the
grate to raise the heat slightly, (he workmen turn over the ore, and (hen close all the
doors.
At the end of two hours, the first fire or roasting being completed, and the doors
shut, the register is to be lifted a little, and coal thrown upon the grate to give the
second fire, which lasts during 25 minutes. When the doors are now opened, the inside
of the furnace is of a vivid rd colour, and the lead flows down from every side towards
the inner basin. The smelter with his rake or paddle pushes the slags upon that basin
back towards the upper part of the sole, and his assistant spreads them uniformly over
the surface through the back doors. The smelter next throws in by bis middle door, a
few shovelfuls of quicklime upon the lead bath. The assistant meanwhile for a quarter
of an hour works the ore and the slags together through the three back doors, and
then spreads them out, while the smelter pushes the slags from the surface of the inner
basin back to the upper part of the sole. The doors being now left open for a titUe,
while the interior remains in repose, the metallic lead, which had been pushed back with
the slags, flows down into the basin. This occasional cooling of the f\imace is thought
to be necessary for the better separation of the products, especially of the slags from
the lead bath.
' In a short time the workmen resume their rakes, and turn over the slags along with
the ore. Three hours after the commencement, a little more fuel is put into the grate,
merely to keep up a moderate heat of the furnace during the paddlmg. After three
hours and ten minutes, the grate being charged with fuel for the third fire, the register
is completely opened, the doors are all shut, and (he furnace is left in this state for
three quarters of an hour. In nearly four hours from the commencement, all the
doors being opened, the assistant levels the surfaces with his rake, in order to fiivonr
the descent of anv drops of lead ; and then spreads the slags, which are pushed back
towards him by the smelter. The latter now throws in a fresh quantity of lime, with
the view not merely of covering the lead bath and preventing its oxidation, btit of
rendering the slags less fluid.
Ten minutes after the third flre is completed, the smelter puts a new eharge of fuel
on the grate, and shuts (he doors of the ftimace to give it the fourth fire. In roar hours
and forty minutes from the commencement, this fire being finished, the doors are
opened, the smelter pierces the tap-hole to discharge the lead into the outer basin, and
throws some quicklime upon the slags in the inner basin. He then pushes the slags
thus dried up towards the upper part of the hearth, and his assistant rakes them oat by
the back doors.
The whole operation of a smelting shift takes about four hours and a hal( or at most
five hours, in which four periods may be distinguished.
1. Thie first fire for roasting the ores requires very moderate firing, and lasts two
hours.
2, The second fire, or smelting, requires a higher heat, with shut doors ; at the end
the slags are dried up with lime, and the ftimace is also allowed to cool a little.
LEAD.
655
3, 4. The last two periods, or the third and/tmrthjina,9it likewise two smeltings or
foandings, and differ from the first only in requiring a hjgher temperature. The heat
is greatesi io the last The form and dunensions of the funaoe are calculated to cause
a uniform distribution of heat o^er the whole surface of the hearth. Sometimes
billets of green wood are plunged into the metaUio lead of the outer basin, causing an
ebullition which favours Uie separation of the slags, and consequentlj the production
of a purer lead ; but no more metallio metal is obtained.
Ten owts. of coal are consumed at Holywell in smelting one ton of the lead-ore Bchtiek
or sludge ; but at Grassington, nsar Skipton in Yorkshire, with a sunilar ftumaoe worked
with a slower heat, the operation taking from seven hours to seven hours and a hft^f,
instead of five, only 74 cw t. of coal are consumed. But here the ores are less refractory,
have the benefit of fluor spar as
a flux, and are more exhausted
of their metal, beins smelted upon
a less sloping hearth.
Tke ort-keiBrtlu — This furnace,
called by the French faumeau
icouaiSf IS from 22 to 24 inches
in height and 1 foot by 1^ in
area mside; but its horisontel
section, always rectangular, va-
ries much in its *<'mfHftions at
different levels, as shown in Jig. -,-. •*«».» «,^
1082 * Tuyere M, Workitone. P, Lead pot.
TrttUmml ofUadorea by the Scotch fumaee or cro^ktartK — ^This Axmace is generally
employed in the counties of Northumberland, Cumberland, and Durham, for the
smelting of lead ores^ which were formerly carried to them without any preparation,
but they are now often exposed to a preliminary calcination. The roasted ore yields
in the Scotch furnace a more considerable product than the crude ore, because it
forms in the fhmace a more porous mass, and at the same time it works drier, to use
the founder's expression ; that is, it allows the stream of air impelled by the blast
to diffuse itself more completely across the matters contained in the furnace.
In proceeding to smelt by means of an ore-hearth» two workmen are required to be
in attendance from the beginnixig to the end of each smelting shift, the duration of
which is from 12 to 15 hours. The first step in commencing a smelting sMft is to fill
up the hearth-bottom, and space below the workstone with peats, placing one already
kindled before the nozzle of the bellows. The powerful blast very soon sets the
whole in a blaze, and by the addition of small quantities of coal at intervals, a body of
fire is obtained, filling the hearth. Roasted ore is now put upon the surface of the
fire, between the forestone and pipestone, which immediately becomes heated red hot
and reduced ; the lead frt>m it sinking down and collecting in the hearth bottom.
Other portions of ore of 10 or 12 lbs. each are introduced from time to time, and the
contents of the hearth are stirred and kept open, being occasionally drawn out and
examined upon the workstone, until the hearth bottom becomes frill of lead. The
hearth may now be considered in its regular working state, having a mass of heated
fuel, mixed with partly frised and semi-reduced ore, called Brouze, fioatins upon a
stratum of melted lead. The smelting shift is then regularly proceeded with by tbe
two workmen, as follows: — The fire being made up, a stratum of ore is spread upon
the horizontal surface of the brouze, and the whole suffered to remain exposed to the
blast for the space of about five minutes. At the end of that time, one man plunges
a poker into the fiuid l^ad, in the hearth bottom below the hrouze, and raises the
whole up, at different places, so as to loosen and open the bronze, and in doing so, to
pull a part of it forwards upon the workstone, allowing the recently added ore to sink
down into the body of the hearth. The poker is now exchanged for a shovel,
with a head 6 inches square, with which the bronze is examined upon the workstone,
and any lamps that may have been too mudi fused, broken to pieces \ those which are
so far a^lutinated by the heat, as to be quite hard, and farther known by their bright-
ness, being picked out, and thrown aside, to be afterwards smelted in the slag hearth.
They are cidled *' grey slags." A little slaked lime, in powder, is then spr^ upon
the bronze, which has been drawn forward upon the workstone, if it exhibit a pasty
appearance ; and a portion of coal is added to the hearth, if necessary, which the
workman knows by experience. In the mean time, his fellow workman, or shoulder
fbllow, clears the opemn^, through which the blast passes into the hearth, with a
shovel, and places a peat immediately above it, which he holds in its proper situation,
until it is fixed, by the return of all the bronze, fhm the workstone into the hearth.
The fire is made up again into the shape before described, a stratum of fresh ore
spread upon the part, and the operation of stirring, breaking the lumps upon the
666 LEAD.
workstone, and picking oat the hard sbigs repeated, after the expiration of a few
minutes, exactly in the same manner. At eyery stirring a fresh peat is put ahoTe
the noxzle of the bellows, which divides the blast, and caoses it to be distributed all
over the hearth ; and as it bums away into light ashes, an opening is left for the
blast to issue freely into the body of the bronze. The soft and porous nature of dried
peat renders it very suitable for this purpose; but, in some instances, where a
deficiency of peats has occurred, blocks of wood of the same size have been used
with little disadvantage. As the smelting proceeds, the reduced lead, filtering down
through all parts of the bronze into the hearth bottom, flows through Uie channel, out
of which it is laded into a proper mould, and formed into pigs.
The principal particulars to be attended to in managing an ore-hearth properly
during the smelting shift, are these : First. — It is Tery important to employ a
proper blast, which should be carefully regulated, so as to be neither too weak, nor
too powerfuL Too weak a blast would not excite the requisite h^U to reduce the ore,
and one too powerful has the effect of fusing the contents of the hearth into slag&
In this particular no certain rules can be given ; for the same blast is not soicable
for every variety of ore. Soft free-grained galena, of great specific gravity, being
very fusible, and easily reduced, requires a moderate blast ; while the harder and
lighter varieties, many of which contain more or less iron, and are often found rich
in silver, require a blast considerably stronger. In all cases, it is most essential, that
the blast should be no more than sufficient to reduce the ore, after every other ne^
cessary precaution is taken in working the hearth. Second. — The blast should be as
much divided as possible, and made to pass through every part of the brouze. Third.
— The hearth should be vigorously stirred, at dae intervals, and part of its contents
exposed upon the workstone ; when the partially fused lumps should be well broken to
pieces, as well as those which are further vitrified, so as to form slags, carefully picked
out This breaking to pieces, and exposure of the hottest part of the brouze upon
the workstone, has a most beneficial effect in promoting its reduction into lead ; for
the atmospheric air immediately acts upon it, and, in Siat heated state, the sulphur
is readily consumed, or converted into sulphurous acid, leaving the lead in its metallic
state ; hence it is that the reduced lead always flows most abundantly out of the hearth
immediately after the return of the bronze, which has been spread out and exposed to
the atmosphere. Fourth. — The quantity of lime used should be no more than is jost
necessary to thicken the brouze sufficiently ; as it does not in the least contribute to
reduce the ore by any chemical effect : its use is merely to render the brouze less
pasty, if, from the heat being too great, or from the nature of the ore, it has a dis-
position to become very soft Fifth. — Coal should be also supplied judiciously ; too
much unnecessarily increasing the bulk of the brouze, and causing the hearth to get
too folL
When the ore is of a description to smelt readily, and the hearth is well managed in
every particular, it works with but a small quantity of brouze, which feels dry when
stirred, and is easily kept open and permeable to die blast The reduction proceeds
rapidly with a moderate degree of heat, and the slags produced are inconsiderable ; but,
if in this state, the stirring of the brouze and exposure upon the workstone are discon-
tinued, or practised at longer intervals, the hearth quickly gets too hot, and imme-
diately begins to agglutinate together; rendering evident the necessity of these
operations to the successful management of the process. It is not difficult to under-
stand why these effects take place, when it is considered, that in smelting by means
of the ore*hearth, it is the oxygen of the blast and of the atmosphere which principally
accomplishes the reduction ; and the point to be chiefly attended to consists in exposing
the ore to its action, at the proper temperature, and under the most fiivoorable cir-
cumstances. The importance of having the ore free from impurities is also evident ;
for the stony or earthy matter it contains impedes the smelting process, and in-
creases the quantity of slags. A very slight difference of composition of perfectly
dressed ore may readily be understood to affect its reducibility ; and hence it is, that
ore from different veins, or the same vein in different strata, as before observed, is
frequently found to work very differently when smelted singly in th^ hearth. It
happens, therefore, that with the best workmen, some varieties of ore require more
coal and lime, and a greater degree of heat than others ; and it is for this reason that
the forestone is made movable, so as either to answer for ore which works with a
large or a small quantity of brouze.
It has been stated that the duration of a smelting shift is from 12 to 15 hours, at the
end of which time, with every precaution, the hearth is apt to become too hot, and it
is necessary to stop for some time, in order that it may cool. At mills where the
smelting shift is 12 hours, the hearths usually go on 12 hours, and are suspended 5 ;
four and a half or five bings* of ore (36 to 40 cwt) are smelted during a shift, andtba
* IbingsScvti.
LEAD.
657
two men wlio manage the hearth work each foor shifts per week ; terminating their
week's work at 3 o'clock on Wednesday afternoon. They are sacceeded hy two other
workmen, who also work fonr 12-hoar shifts ; the last of which they finish at 4 o'clock
on Saturday. In these eight shifts, firom 36 to 40 hings of ore are smelted, which,
when of good quality, produce ftt>m 9 to 10 fodders* of lead. At other mills where
the shift IS 14 or 16 hours, the furnace is kindled at 4 o'clock in the morning, and
worked until 6 or 7 in the evening each day, six days in the week; during this shift,
5 or 5^ bings of ore are smelted, and two men at one hearth, in the early part of each
week, work three such shifts, producing about 4 fodders of lead — two other men
work each 3 shifts in the latter part of the week, making the total quantity smelted
per week, in one hearth, from 30 to 33 bings.
Hearth-endM and Smelter's fume, — In the operation of smelting, as already de-
scribed, it happens that particles of unreduced and semi-reduced ore are continually
expelled from the hearth, partly by the force of the blast, but principally by the
decrepitation of the ore on the application of heat. This ore is mixed with a portion
of the fuel and lime made use of m smelting, all of which are deposited upon the top
of the smelting hearth, and are called heuth-ends. It is customary to remove the
hearth-ends from time to time, and deposit them in a convenient place until (he end
of the year, or some shorter period, when they are washed to get rid of the earthy
matter they may contain, and the metallic portion is roasted at a strong heat, until it
begins to soften and cohere into lumps, and afterwards smelted in the ore-hearth,
exactly in the same way as ore undergoing that operation for the first time, as already
described.
It is difficult to state what quantity of hearth-ends are produced by the smelting of
a given quantity of ore, but in one instance the hearth-ends produced in smelting 9751
bings, on being roasted and reduced in the ore-hearth, yielded of common lead 315 cwt.,
and the grey slags separated in this process gave, by treatment in the slag-hearth, 47
ewt. of slag lead ; making the total quantity of lead 362 cwt, which is at the rate of
3 cwt 2 qrs. 23 lbs. from the smelting of 100 bings of ore.
Slag 'hearth. — The various slags obtained from the different operations of lead
smelting are divided into two classes. Those which do not contain a sufficient amount
of metal to pay for further treatment are thrown away as useless, whilst those in which
the percentage of lead is sufficienUy large are treated by the slag-hearth.
Fige. 1083, 1084 represent a slag-hearth, ih&foumeau d manche (elbow furnace) of
the French, and the krummqfen (crooked furnace) of the Germans ; such as is used
at Alston Moor, in Cumberland, for the reduction of the lead-slag. It resembles the
Scotch furnace. The shaft is a parallelopiped, whose base is 26 inches by 24 inches in
area inside, and whose height is 3 feet ; tiie sole-plate a, of cast iron, slopes slightiy
[L^l-hsJ^j
\
1084
down to the basin of reception or the fore-hearth b. Upon both of the long sides of the
sole-plate there are cast iron beams, called bearers^ c c, of great strength, which sup-
port the side walls built of a coarse grained sandstone, as well as the cast iron plate d
(/bre-etone^ which forms the front of the shaft This stands 7 inches off fVom the sole-
plate, leaving an empty space between them. The back side is made of cast iron,
from the sole-plate to the horizontal tuydre in its middle ; but above this point it is
made of sandstone. The tuyere is from 1^ to 2 inches in diameter. In front of the
fore-hearth b, a cistern e is placed, through which water continually flows, so that the
slags which spontaneously overflow the fore-hearth may become inflated and divided,
whereby the lead disseminated through them may be readily separated by washing.
The lead itself flows from the fore-hearth b, through an orifice, into an iron pot/,
which is kept over a fire. The metal obtained from this slag-hearth is much less
pnre than that extracted directiy from the ore.
The whole bottom of the furnace is filled to a height of 17 inches, that is, to
within 2 or 3 inches of the tuyere, with the rubbish of coke reduced to coarse powder
and beat strongly down. At each smelting shift, this bed must be made anew, and the
interior of the ftxmace above the tuyere repaired, with the exception of the fr^nt, con-
sisting of cast iron. In advance of the furnace there is a basin of reception, which is
also filled with coke rubbish. Farther off is the pit, ftiU of water, replenished by a cold
Vol. II.
• 1 raddors2i ewts.
UU
658 LEAD.
ttreun, vhich inceuiDtly rum in throagh m pipe- The tcoiia, in floving ont of the
furnace, pHM aver Ihe coke bed in the liMiD of reception, and then &11 into the vater,
vhOBe coolneu mokes them &j Lnlo (mall piecei, i^r vhich they are eatUj mihed,
GO as to separate the lead that may be entangled among them.
Thesefumaceiareurgedaometimeibjfiuuorbf wooden bdlovtijf^. 108S. BetM
the «melting vork* of Lti,
near Matlock, the Moving-
machine coniiata of two [mil
vhicb more upon horiiaital
axes. Each of these caiki ii
diTided into two equal para
by a fixed plane that fiai i
tfaioagh ib aiia, and i» filled
irith irater la a certain height.
The Tater of one side connna-
nicates with that of the otb«r
bj an opening in the lower
part of the diviiitKi. Each
cask possesses a moTcmenl of
oscillation, prodnoed by a rod attached to a crank of a backet-vheel. At each demi-
oscillidoD, one of the compartments, being in communication with the eitcrnat air,
is filled ; whilst the other, on the contrary, communicates with the noiile, and snpiriies
wind to the furnace.
Insread of being blown by a cold blast, these rnmacet are sometimes aapplied with
healed air. When smelting with cold air, it is often fonnd difficnit to proportion Uk
quantity of slag or other gubatance operated on, so as to preserve the noee or cone of
slag which forms at the end of the tnyire from growing too long, to the prq'udiee of
the operation. When the snbetance operated on is poor for melal, and very refraelory,
it fVequently happens that the smelter is obliged lo break the nose, or introduce some
verj fusible inheUnoe in order to melt it off. Bj the introduction of hot air this in-
convenieuce is removed, since by increasing or lowering tbc temperatore of the blast,
the nose may be allowed to lengthen or shorteo, according as the nature <^ the slags
may require. The temperature foand to answer best is from S50° to 300° Fahr.:
since when it is healed to fhim 600° (o 600°, it is fonnd impossible to form a noie of
sufilcient length to convey the blast to the front of (he hearth, and therefore the
back, vhich is expensive to rebuild, is quickly destroyed.
The advantage to be derived from the use of the hot blast will be evident, torn the
result ot two experiments which were tried some yean since.
Twenty-eight tons of slag smelted with cold blast consumed 39! cubic feet tt air
per minute.
Labour cost - -.- ---£3 76
Coke, T tons, at S4s. S£ 8 116
Total £ll 19 3
Thirty-five tons of similar slag smelted with hot blast consumed 300 cuUe fM of
air per minute.
Labonr cow ------- tsis
Coke, 5 tons, 17 cwt., »t2U.Sd.- - - 7 3 4
Torf for heating air, 1 1 toads, U.Sd. - • 0 IS 4
Total £11 9 4
From which it will be seen that, with ane-quarter part less air, a quarter part BMce
slag was melted per week, and a saving of expense of nearly lOi. effeiMed.
The ioss of lead experienced in smelting by the slag hearth, is, however, very great,
even under the most favourable circumstances; and it has. can sequently, of later years
been gradually superseded by the Caslilian furnace, which will be shortly described.
Many large and well-conducted establishments still howeTer contlnae (o employ the
slag hearth, and when well constructed and skiifally managed, the loss ariaiDg friHU
volalitisalian may be eansiderably reduced.
CaMtUitm fimace. ~ Within the last few j^ears a blast furnace has been
introduced into the lead works of this coantry, which possesses grest advantages over
every other description of apparatus which has been hitherto employed for the
treatment of lead ores of low produce. This apparatus, allhougb first employed in
Bpain, was invented by an EDglishmaD (Mr. W. Ganndry), who wu employed in the
reduction of rich slags in the neighbourhood of Carthogena.
This furnace is circular, usnally aboat a feet 4 inches, or 9 feet 6 inche* is
LEAD. 659
diameter, and is eongtraeted of the best fire-bricks, so moulded as to fit together, and
aUow all the joints to follow the radii of the circle described by the brick work. Its
usual height is 8 feet 6 inches, and the thickness of the masonry inyariably 9 mches.
In this arrangement the breast is formed by a semi-circnlar plate of cast-iron,
famished with a lip for running off the sUig, and has a longitudinal slot, in which is
plaeed the tapping-hole.
On the top of this cylinder of brickwork a box-shaped covering of masonry is
supported by a cast-iron firaming, resting on four pillars, and In this is placed the
door for feeding the fhmace, and the outlet by which the various products of
combustion escape to the flues. The lower part of this hood is fitted closely to the
body of the furnace, whilst its top is closed by an. arch of 4 J inch brickwork laid in
fire-clay. The bottom is composed of a mixture of coke-dust and fire-clay, slightly
moistened, and well beaten to the height of the top of the breast-pan, which stands
nearly 3 feet above the level of the floor. Above the breast-pan is an arch, so
turned as to form a sort of niche, 18 inches in width, and rather more than 2 feet
in height
When the bottom has been solidly beaten, np to the required height, it is hollowed
out so as to form an internal cavity, communicating freely with the breast- pan,
which is filled with the same material and subsequently hollowed out to a depth
slightly below the level of the internal cavity. The blast is supplied by three water
tuyeres, 3 inches in diameter at the smaller end, 5^ -inches at the larger, and 10
inches in length. Into these the noszles are introduced, by which a current of air is
supplied by means of a fim or ventilator, making about 800 revolutions per minute.
The blast may be conveniently conducted to the nozzles through brick channels formed
beneath the floor of the smelting house.
The ores treated in this furnace ought never to contain more than SO per cent of
metal, and when richer, must be reduced to about this tenure by the addition of slags
and other fluxes. In charging this apparatus, the coke and ore are supplied stratum
super stratum, and care must be taken so to dispose the coke as not to heat too
violently the brickwork of the ftimaces. In order to allow the slags which are pro-
duced to escape freely into the breast- pan, a brick is left out of the front of the
furnace at Uie height of the fore-hearth, which, for the purpose of preventing the
cooling of the scorise, is kept covered by a layer of coke-dust or cinders. From the
breast-pan the slags flow constantly off over a spout into cast-iron waggons, where
they consolidate into masses, having the form of tnmcated pyramids, of which the
larger base is about 2 feet square. As soon as a sufficient amount of lead is
accumulated in the bottom of the furnace, it is let off into a lateral lead-pot, by
removing the clay-stopper of the tap-hole situated in the slot of the breast-pan, and
after being properly skimmed it is laded into moulds. When in addition to lead the
ore treated likewise contains a certain portion of copper, this metal will be found in
the form of a matt floating on the surface of the leaden bath. This, when sufficiently
solidified, is removed, and after being roasted is operated on for the copper it contains.
' The waggons in which the liquid slag runs off, are frequently made to traverse
small railways, by which, when one mass has been removed, its place may readily be
supplied by an empty waggon. When nearly cold the casings of the waggons are
turned over and the blocks of slag easily made to drop out In addition to the facility
for transport obtained in this way, one of the great advantages obtained by this
method of manipulation arises from the circumstance that should the furnaces at any
time run lead or matt, without its being detected by the smelter, the whole of it will
be collected at the bottom of the block, from which, when cold, it may be readily
detached.
In working these furnaces, care must be taken to prevent flame from appearing
at the tunnel-head, since, provided the slags are sufficiently liquid, the cooler the
apparatus is kept the less will be the loss of metal through volatilisation. In addition
to the greatest attention being pud to the working of the furnace, it is necessary, in
order to obtain the best results, that all establishments in which this apparatus is
employed should be provided with long and capacious fines, in which the condensation
of the fumes takes place, previous to arriving at the chimney-shaft These fiues
should be built at least Uiree feet in width, and six feet in height, so as readily to
admit of being cleaned, and are often made of several thousand yards in length. The
value of the fomes, so condensed, amounts to many hundreds, and in some instances
thousands per annum.
In order to be advantageously worked in these furnaces, the ores should be first
roasted, and subsequently agglomerated into masses, which, after being broken into
fragments, of about the size of the fist, and mixed with the varions fluxes, are charged
as before described.
In an establishment in which the average assay produce of the roasted ore for lead
uu 2
660 LEAD.
U 43]tht, the fomtM yield ii 3S^]tlu, uid the veight of coke emplofed to effect
the rednctioii SS p«r cent of tbe routed ore opersted on. The mixture chained iato
the ftinuce, in thit inttuce, ■■ composed of 100 porta of routed ore, 42 para of ib^
fh>m a previom operatioa, B porta of acrap iron, and 7 parti of limestone. Each
fiinuiM vorka off about lereQ toiia of roMted ore in the coune of 2i boon ; the
Teif^t of *!«£« nm off is aboni double that of tbel^d obtained, and (he maltrenured
fVom the nrftce of the pan i* Dearlj 5 per cent, of the lead prodaced. The act*
treated in thii eitabliahment contitl of g^ena, moch mixed with apathose iroa, and
•re therefore Bomevhat reftmctory. A fbriiaceofthiilund require* tbr its conttmclioo
•bout 1000 iegmental flr«-bricki, and the lame number of ordinary fire-bricka of
•ecoDd ijiialitj.
I08S lOST
LEAD.
661
Figt. 1086, 1087» 1088, and 1089 represent respectively a yertical section, an elevation^
a ground plan, and an horizontal section of a Castilian Aimace. The section ^^. 1089
is on the line x T,fig, 1087. a is the hody of the fhmace, B, the bottom composed of
a mixture of coke-dust and fire-clay ; c c c, the tuyeres ; d, the rectangular coTcring of
masonry ; b s e s, cast iron pillars ; f, the breast-pan ; a, slot for tapping hole ; h, lip
of breast-pan; i, feeding door ; k, fiue-hole; p, q, ground line.
Fiffa, 1090, 1091 are the slag-waggons, a being a moTable case without a bottom,
and B a strong cast-iron plate running on four wheels.
1090
0
The desulphuration of the ores to be treated in these ftimaees may be effected either
by the aid of an ordinary rererberatory roasting furnace, or in heaps, or properly
constructed kilns.
The kilns best adapted for this purpose consist of rectangular chambers, having an
arched roof, and provided with proper flues for the escape of the evolved gases, as
well as a wide door for charging and withdrawing the ore to be operated on.
Each of these chambers is capable of contaming from 25 to 30 tons of ore, and
in order to charge it a layer of faggots and split yrood is laid on the floor, and this,
after having been covered by a layer of ore about two feet in thickness, is ignited,
eare being at the same time taken to close, by means of loose brick-work, the open-
ing of the door to the. same height When this first layer has become sufficiently
ignited, a fresh stratum of ore, mixed with a little coal or charcoal* is thrown upon it,
and when this layer has in its turn become sufficiently heated, more ore is thrown
on. In this way more ore is from time to time added, until the kiln has become full,
when the orifice of the doorway is closed by an iron plate, and the operation proceeds
regularly and without further trouble until the greater portion has become eliminated.
This usually happens at die expiration of about four weeks from the time of first
Ignition, and the brick-work front is then removed, and the ores broken out, and after
being mixed with proper fiuxes, passed through the blast furnace.
The proportion of wood necessary for the roasting of a ton of ore by this means
must necessarily depend on the composition of the minerals operated on ; but with ores
of the description above-mentioned, and in a neighbourhood where wood is moderately
cheap, the desulphuration may be effected at a cost of about Sa. per ton.
Calcining. — The lead obtained by the various processes above described generally
contains a sufficient amount of silver to render its extraction of much importance ;
but, in addition to this, it is not imfrequently associated with antimony, tin, copper, and
various other impurities, which require to be removed before the separation of the
silver can be effected.
This operation consists in fbsing the hard lead in a reverberatory Aimace of peculiar
construction, and allowing it to remain, when in a melted state, exposed to the oxi-
dising influences of the gases passing through the apparatus. By this treatment the
antimony, copper, and other impurities become oxidised, and on rising to the surface
of the metallic bath are skimmed off, and removed with an iron rake. The hearth of
the furnace in which this operation is conducted consists of a large cast-iron pan,
which may be 10 feet in length, 6 feet 6 inches in width, and 10 inches in depth. The
fire-place, which is 1 foot 8 inches in width, has a length equal to the width of the
pan, and is separated from it by a fire-bridge 2 feet in width. The height of the arch
at tiie bridge end is 1 foot 4 inches above the edge of the pan, whilst at the outer
extremity it is only about 8 inches.
The lead to be introduced into the pan is first fused in a large iron pot fixed in
uu 3
663 LEAB,
brick-work ftt the nde of the ftvntce, ui4 laliceqiKiitlj Uded into it thiangh aa inn
gnUer idapted for that pnrpote. The length of time aeeeatrj for the pnnEcttioD et
bud lead obvionsl; depend! on the nature uid smounl of the impmitiei which it
contains; and, conBequentl;, some vineties vitl be suffidentlj improTed at iLe ex-
piralioD of twelve hoars, whilst in other iostancea it ia neceaaary to contiaoe the
operation duriag three or four weeka. The charge of bard lead TUies from eight lo
eleven tons.
When the metal ja thought to be in a St stale for tapfMug, a small portion taken eat
with a ladle, and poured into a monld used for thia pnrpou is found on coaling to
aaaume at the buiI^c a peculiar crystalline appearanee. which when once aeen ii
readily again recognised. Aa soon a« thia appearance preaenta ilaelf an iron plug is
withdrawn from the bottom of the pan, and the lead no off into an iron pan, boa
which it is snbaeqaentlj laded into monlda.
The items of cost attending the calcination of one ton of hard Spanish lead in the
north of Eugland are about as fijUowa : —
Wages 1 11-2
Coato, 2-T cwl 0 *7
Bepain, && -..-..--00-5
The coDstmction of a fiirnace of thig description requires 5000 common bricks.
9,500 Gre-bricka, and a tons of fire claj.
Figt. 1093 and 10S3 represent an eleration and Tertical aection of the "'"'"™j
pit; cflre-bridge; d, cast iron pan ; B,fliiei rrr.
noistorei o, one of Ibe working doon ; h, spout ftar
mntliog off calcined metal Fig. 1094 i«-
preaenla the pan removed from the nuaoary,
and shows a rrooTe in the lip for the iniro-
daetioD of a sheet-iron dam. tightened with
moistened trane-aah tor keeping in the fused
In the more modem furnaces of thia de-
scription, the comers are usaall; iwrnded
to prevent breakage from expaniion, whilst
the tapping ia effected hj meana of a hole
through the bottom near one of the sides.
This, when dosed, is slopped by means of
an iron plog kept in its place byaweighted
vben lead eoBtaining tUvtr n UMltod in m saitmble Tctftl, aAcrwardi ilovlj allowed
to cool, Rod *l the Mme time kept eonnuitljr idrred, tt a certain tempentare oear the
neliiDg point of lead, mettllio crjttala begin to form. These ■■ rapidly aa Ihej are
•Uver than the lead oriKinall; operated
on. The atill floid portion, from irhich
the cryMali have been removed, will
at the same time be proportionaltj ea-
ia condneted ii
iched.
This operatic
riei of B or 10 can iron pou, hi m a
row, vilh flrepUceg beneath. These
arc eada capable of containing abont
8 tons of calcined lead ; and ou com>
eocing an operation that qnantit; nf
inetai,eoiitainiDg«e 'will suppose 30 oi.
of gilTer per ton, is introduced into a pot
Cnjr,fig. 109S)aboiit the centre ofthe
series. Thii when melted, is carefblly
■kimmed with a perforated ladle, aLd
the fire immediately witbdraira, The
cooling of the melal i« alw freqneotly
hastened bj throiring "Ster upon its
snrfsce, and whilst cooling it is kept
coDstantl/ agitated bj means of a long
iron stirrer or slice. Cryitals soon
begin to make their appearance, and
the«e as they accomnlate and fall to the
bottom are removed b^ means of a
targe perforated ladle, in which they
are well shaken, and afterwsrdl car-
ried over to the next pot to the left of
the workman. This operation goes on
continually until about i tons of crys-
tal* have been taken one of the pot r,
and have been placed in pot x, at
which time the pat r, may contain aboot
40 01. of silver to the ton, whilst that
in E, will only yield 10 oz. The rich
lead in t, is then laded into the neif
pot o, to the right of the workman, and
the operalion repeated in f, on a &eah
quantity of calcined lead.
In this way calcined lead it eon-
■tantly introdnccd, and the resulting
poor lead pastes continually to tbe left
irf the workman, whilst the rich it
passing towards his right. Each pot
in SDCcestion, when filled with lead of
its proper prodnce for ailver, ia in its
torn crystallised, the poor lead passing
to the left of the workmsn, and the
aoriched lead to his right By this
method of treatment it is evident that
the crystals obtained ttom the pots to
(he left of the workman most gradu-
ally be deprived of their silver, whilst
the rich lead pasting to his right be-
comes continually richer. The final
result is, that at one end of the aerica,
the poor lead containe very little silver,
whilst at the other an exceedingly rich
•Hoy of lead and silver is obtained.
The poor lead obtained by this pro-
cess should never contain more than
tS dwts. of ailter per ton, whilst the rich lead is f^nently c
to the ton. This rich lead it snhaeqiiently copelled in the icSniag farnaee.
664
LEAD.
Th« ladle emploTed for tha ranoTal of the crystsli, when muul Imboor u m*de
DM of, U >bont 16 iDchea Id diameter, and 5 iochea in depth, bat when cranei are
lued macb larger ladlea are eaaily managed. A form of eruie hu been iHTentciI
irhich effects coniiilereble economy of labour in thii operation. When, dnring the
operation of ciyatallisation, the ladle becomes chilled, it ia dipped into a anull leaacl
containing lead of a higher temperature than that which it being worked, and knovn
bj the name of a temper-pot. The pot coptainiog Ibe rich lead i* generally called
the No. 1 pot ; in some eslablisbmenti, howeTer, the laat pot in which the poor lead
it erj^ttallised obtains this appellation.
Figt. 1095 and 109G represent a plan and el«Tation of a act of Pattinsoa'a pota,
arranged in the most approved way. a ii the " market pot," from which the denl-
leriaed lead ii laded out B, c, D, E, r, o, B,andi, are the working pott, whilst A.', >*, (/,
d', b', T',a', u', and i, areiheir reapective Breplacei. The " lemper-pota " us a n, are
employed for healing the ladle* when ihej hare become toa mnch reduced in lea-
peratare.
The jfifi. 1097 and 1 09B, are sections showing the manner of letting and the alTUp
meni of the pots and floet. A, pot; b, mun floe; c, aah pit.
1097
The cost of cr^ atalliiing one ton of calcioed Spanish lead, in the e
qaoled when ireatmg of calcination, ia aa follow* : —
™ •• <^
WaM 9 5-4
Coals, i cwta. .......oe'4
Bepaii* o a-a
Total 10 4-3
The erection of nine dx-ton pou requires 15,000 common bricks, 10^3 flre-brick*.
160 feet of quarles, BO Ere-cUj blocks, and S ton* ot fire-cisj.
In *ome efltabliRhmcnts (en-ton pots are employed, and where crane* Are nude use
of they ore fonnd to be advanlageoDS.
SeJiKing. — The extraction of the silver contained in the rich lead i* condndad in a
ctipal forming the bottom of a reverberatorj furnace called a refinery.
LEAD. 665
In this opmtion the litharge prodaced, instead of being absorbed bj the substance
of the cupel, is run off in a fluid state, by means of a depression called a gate.
The size of the fire-place Taries with the other dimensions of the furnace, but is
usually nearly square, and in an apparatus of ordinary size may be about 2 feet x S
feet 6 inches. This is separated from the bod^ of the furnace by a fire-bridge 18
inches in breadth, so that the flame and heated air pass directly over the surface of
the cupel, and from thence escape by means of two separate apertures into the main
flues of the establishment The cupel or test consists of an OTal iron ring, about 5
inches in depth, its greatest diameter being 4 feet, and its lesser nearly S feet This
fhune, in order to better support the bottom of the cupel, is provided with cross-bars
about 4^ inches wide, and one half-inch in thickness. In order to make a test, this
frame is beaten full of finely-powdered bone-ash, slightly moistened with water, con-
taining a small quantity of pearl-ash in solution, which has the property of giying
consistency to the cupel when heated.
The centre of the test, after the ring has been well- filled with this mixture, and
solidly beaten down, is scooped out with a small trowel, until the sides are left 2 inches
in thickness at top, and three inches at the bottom, whilst the thickness of the sole
itself is about 1 inch.
At the fore part or wide end of the test the thickness of the border is increased to
six inches, and a hole is then cut through the bottom, which communicates with the
openings or gates by which the fluid li&arge makes its escape.
The test, when thus prepared, is placed in the refinery furnace, of which it forms
the bottom, and is wedged to its proper height against an iron ring firmly built into the
masonry. When this furnace is first lighted, it is necessary to apply the heat ver^
gradually, since if the test were too strongly heated before it became perfectly dry, it
would be liable to crack. As soon as the test has become thoroughly dry, it is
heated to incipient redness, and is nearly filled with the rich lead to be operated on,
which has been previously fused in an iron pot at the side of the fUmace, and beneath
which is a small grate where a fire is lighted.
The melted lead, when first introduce into the furnace, becomes coyered with a
greyidi dross, but on further increasing the heat, the surface of the bath uncovers,
and ordinary litharge begins to make its appearance.
The blast is now turned on, and forces the litharge fh>m the back of the test up to
the breast, where it passes over the gate, and faUs through the aperture between
the bone-ash and the ring into a small cast-iron pot running on wheels. The air,
which is supplied by a small ventilator, not only sweeps the litharge from the sur-
face of the lead towards the breast, but also supplies the oxygen necessary for its
formation.
In proportion as the surface of the lead becomes depressed by its constant oxidation,
and the continual removal of the resulting litharge, more metal is added from the
melting pot, so as to raise it to its former level, and in this manner the operation is
continued until the lead in the bottom of the test has become so enriched as to render
it necessary that it should be tapped. The contents of the test are now so far reduced
in volume that the whole of the silver contained in the rich lead operated on remains
in combination with a few hundred weights only of metal, and this is removed by
carefully drilling a hole in the bone-ash forming the bottom of the test The reason
for the removal of the rich lead, is to prevent too large an amount of silyer from
being carried off in the litharge, which is found to be the case when lead containing
a very large amount of that metal is operated on.
When the rich lead has been thus removed, the tapping hole is again closed by a
pellet of bone-ash, and another charge immediately introduced.
As soon as the whole of the rich lead has been subjected to cupellation, and has
become thus further enriched, the argentiferous alloy is itself similarly treated, either
in a fresh test, or in that employ^ for the concentration of the rich lead. The
brightening of pure silver at the moment of the separation of the last traces of lead,
indicates the precise period at which the operation should be terminated, and the blast
is then turned off, and the fire removed fh}m the grate. The silver is now allowed
to set and as soon as it has become hardened, the wedges are removed from 'beneath
the test, which is placed on the floor of the establishment When cold, the silver
plate is detached from the test, and any adhering particles of bone-ash removed by
the aid of a wire brush.
A test furnace of ordinary dimensions requires for its construction about 2,000
common bricks, 2,000 fire-bricks, and 1^ tons of fire-clay. A furnace of this kind
will work off 4 pigs of lead per hour, and consume 4 cwts. of coal per ton of rich
lead operated on.
The cost of working a ton of rich lead in the neighbourhood of Newcastle, con-
taining on an average 400 oz. of silver per ton, is as follows : —
Figt. 1099, IIOO, and 1101, repretent an elevation, plan, and aection of a reGning
ftirnace; a, fireplace) b, ash-pit; c, flre-brid^; d, teet-riQg, Bbown Id iu proper
poiilian; b, flout ', point where blast enteral o, pig-hole*.*
•Plg-lici1cianuudfarlDtnidudDlUigl«rl in cuei In ■hich It ii dm laded Into Ux UM Id ■ tiued
LEAD.
667
^Afiidfi^.— The redacUon to the metallic state of the litharge fh>m the refinery,
the pot dross, and the mixed metallic oxides from the calcining furnace, is effected in
a reverberatory apparatus, somewhat resembling a smelting fiimace, except that its
dimensions are smaller, and the sole, instead of being lowest immediately below the
middle door, gradually slopes from the fire-bridge to near the fiue, where there is a
depression in which is inserted an iron gutter, which constantly remains open, and from
which the reduced metal flows continuously into an iron pot placed by the side of the
furnace for its reception, whence it is subsequently laded into moulds.
The litharge, or pot dross, is intimately mixed with a quantity of small coal, and is
charged on that part of the hearth immediately before the fire-bridge. To prevent
the fused oxide from attacking the bottom of Uie furnace, and also to provide a sort
of hoUow filter for the liquid metal, the sole is covered by a layer of bituminous coal.
The heat of the furnace quickly causes the ignition of this stratum, which is rapidly
reduced to the state of a spongy cinder. The reducing gases present in the furnace,
aided by the coal mixed with the charge itself, cause the reduction of the oxide, which,
assuming the metallic form, flows through the interstices of the cinder, and ultimately
finding its way into the depression at the extremity of the hearth, flows through the
iron gutter into the external cast iron pot The surface of the charge is frequently,
during the process of elaboration, turned over with an iron rake, for the double pur-
pose Sf exposing new surfaces to the action of the furnace, and also to allow the
reduced lead to flow off more readily.
Fresh quantities of litharge or pot-dross, with small coals, are from time to time
thrown in, in proportion as that already charged disappears, and at the end of the
shift, which usually extends over 12 hours, the floor of cinder is broken up, and after
being mixed with the residual matters in the furnace is withdrawn. A new floor of
cinders is then introduced, and the operation commenced as before. A furnace of
this kind, having a sole 8 feet in length and 7 feet in width, will afford, from litharge,
about 5^ tons of lead in 24 hours.
The dross from the calcining pan, when treated in a furnace of this description,
should be previously reduced to a state of fine division, and intimately mixed up with
small coal and a soda-ash. In many cases, however, the calcined dross is treated in
the smelting furnace. The hard lead obtained from this substance is again taken to
the calcining furnace, for the purpose of being softened.
The expense of reducing one ton of litharge may be estimated as follows : —
a. d.
Wages ---. 2 6-0
Coals (3 cwts.) 0 6-2
Repairs 0 1*6
Total - - - 3 0-8
In the establishment firom which the foregoing data were obtained, the cost of slack,
delivered at the works, was only 2«. Ud per ton, which is cheaper than fuel can be
obtained in the migority of the lead^mills of this country. In North Wales the cost
of small coal is generally about 4«., and at Bristol 5s. 6<2. per ton.
1102
Figi. 1102 and 1103 represent a vertical section and plan of a reducing furnace, a,
fire-place ; b, ash-pit 5 c, fire-bridge ; d, hearth ; b, working- door ; p, iron spout for
668
LEAD.
condaotiDg the redaeed metal into the lead-pot a, which is kept heated by
a fire beneath.
103
B. -H— R' ° ^
neaiis of
The total cost of elaborating one ton of hard lead, contuning 80 ox. of nlver per
ton, in a locality in which fuel is obtained at the low price above quoted, is neariy as
follows : —
£ 9. d.
Calcining 02 4-4
Crystallising - - - - - - -09 6*5
Refining Oa9'S
Redacing— pot dross and litharge - - • 0 1 0*8
Calcined dross - - - - - - -00 8*0
Slags 00 5*0
BoDC-ash, &C. - - - - - - -00 7-0
Transport, &c. - -011^
Management, taxes, and interest of plant - - 0 5 10-0
Total - - •12 3-9
One hundred tons of hard lead treated gaye:—
Tons.
Soft lead 94*90
Black dross 3*72
Loss --------- i'38
Total ... 100*00
On comparing the expense of each operation, as giyen in the foregoing abstract,
with the amounts stated as the cost of each separate process, they will be found to
be widely diJBTerent ; but it must be remembered that the whole of the substances
elaborated are fu from being subjected to the various treatments described.
In order therefore to give an idea of the relative proportions which are passed
through the several departments, I may state that in an establishment in which the
ores are treated in the Castilian furnace the following were the results obtuned : —
One-hundred parts of raw ore yield : —
Roasted ore -..-.-..85
Hard lead - 42
Soft „ 36
Rich „--..---. 9
Dross and litharge re-treated . . ^ . i8^
The importance of this branch of our metallurgic indastry will be gathered from
the following tabular statements, chiefly derived from Mr. Hunt* s iraluable statis-
tics:—
LEAD.
669
TAia.B L
Showing the Quantity of Lead Ore raised and emeUedj average Metallic Yield of Ore
per Cent, and Ratio of Lead produced in vturious Parts of the Uiiited Kingdom
during Ten Years ending 1857.
Tmb.
Riw!»fMti
Walfli.
IniauL
ia<Mi^la«>j|-
Ida of Man.
TMaL
LMd
On.
Lead.
Lc«l
On.
L-d.
liMd
Or*.
Laad.
Laad
On.
Laad.
Laad
Laad.
Lnd
Ore.
Laad.
1848 - -
1849 - -
1850 -
1891 . -
1892 -
1893 •
1854 . .
1869 - -
1896 - -
1807 - -
Avenge me.
ullic jrleld
per cent, of
ore -
RjiCiAoflewi
produced -
Tbma.
94,938
60,124
63,569
64.102
62,411
99,342
64,796
66,870
74,489
68,920
TtoM.
39,142
41,168
44.462
49,103
43,813
41,887
44.986
46,244
92,868
48,396
Tomt.
16,309
19,711
21,093
19314
18379
17,131
18,180
18,206
19,873
21,499
Tam.
11,122
13,389
14,876
14,813
13,708
18,870
13367
13.673
14,791
16,184
TbM.
1,912
2^
2,899
8,222
4,493
3,309
3.069
2,409
2,484
2,289
Toma.
1,188
1,693
1.746
1,829
8,282
2,492
2,210
1,732
1,608
1,407
Toma.
2,988
1,421
3,117
8,113
8.499
2,799
1,793
1367
1,931
1,891
Tomt.
1,736
957
2,124
2.140
2,381
1,919
1,279
1,199
1,417
1,391
Toma.
2321
2,826
2,179
2,560
2,419
2,460
2,800
3,973
3,218
2,656
Tma.
1,669
1,935
1,218
1,402
1,839
1.829
2,137
2,729
2,491
2.028
TVnw.
77,864
86,881
92349
92311
91,197
a%041
90.948
92.041
101,997
96,821
Toma.
94,843
98.708
64,426
65,287
64,958
6036?
63.979
65.933
73.129
96,366
638,197
448,009
189397
138,783
28,827
,041
23,609
16.463
27,204
18,829
907,486
641,101
70-2
G9^
781
217
66-0
3-0
69-4
2-9
691
21
70-6
100
Table II.
Estimated Value of Lead and Stiver consumed in Great Britain, 1857.
Lead and silyer produced in the United Kingdom . . - £1,670,353
Silyer imported, 846,569 ox. ---•-.- 232,806
1,903,159
Lead exported ..... 22,397 tons.
„ imported ..... 12,768 „
Balance of exports .... 9,629 • . - 211,838
Valoe ooDSomed ..... *£ 1,691,321
Table III.
SUver produced from Ores raised in Great Britain during Four Years ending 1857.
England ....
Wales
Ireland ....
Scotland ....
Isle of Man ....
Total ...
Yalne at 5s, Sd, per oz. -
1894.
1899.
1896.
1897.
Ox.
419,824
67,051
18,096
5,426
52,262
Ox.
439,983
57,521
7,252
4,947
61,597
Os.
481,909
62,357
3,700
5,289
60,382
Os.
417,343
58,097
3,071
4,206
48,016
562,659
561,300
613,637
530,733
£154,730
154,357
158,750
146,501
Market valae of lead prodaced in the United Kingdom in 1857 - £1,523,852
Ditto of silver 146,501
1,670,353
It may be remarked that for the treatment of ores of good prodnee the reverbera*
tory furnace and Scotch hearth are to be preferred, but for working minerals of a
low percentage the blast furnace may generally be substituted with ad?antage.
The slag hearth, from the amount of fuel consumed and loss experienced, is a somewhat
expensive apparatus, and might in many cases be advantageously exchanged for the
Castilian furnace.
It is well known that the losses which take place In this branch of metallurgy are.
670 LEAD OBES^ ASSAY OF.
from the Tolatility of the metal operated on, oniuaallj large. In thoae establiali-
ments, however, in which due attention is paid to flaxes and a proper admixtore of
ores, as well as the condensation of the fumes, a great economy is effected.
In some instances flues of above five miles in length have been constmeted, and the
most satisfactory results obtained. The attention of lead smelters is being daily more
directed to the prevention of the loss of metal by volatilisation, and those who have
adopted the use of long flues have been, in all cases, quickly repaid for their outlay.
As an example of the great extent to which snblimation may take place on the scale
employed in large smelting works, we may mention the lead works belonging to
Mr. Beaumont in Northumberland. Formerly the fhmes or smoke arismg from
various smelting operations escaped from ordinary chimnevs or short galleries, and
large quantities of lead were thus carried off in the state of vapour, and deposited oo
the surrounding land, where vegetation was destroyed, and the health of both men
and other animals seriously affected. This led to various extensions of the hori-
zontal or slightly inclined galleries now in use, and the quantity of lead extracted
rapidly repaid the cost of construction. The latest addition of this kind was made
at Allen Mill, by Mr. Sopwith, the manager, and completed a length of 8,789 yards
(nearly five miles) of stone gallery from that mill aJone. This gallery is 8 feet
high and 6 wide, and is in two divisions widely separated. There are also upwards
of 4 miles of gallery for the same purpose connected with other mills belonging to Mr.
Beaumont in the same district, and in Durham ; and we leam from Mr. Sopwith,
that further extensions are contemplated. The value of the lead thus saved from
being totally dissipated and dispersed, and obtained from what in common parlance
might be called chimney sweepings, considerably exceeds 10,0002. sterling annually,
and forms a striking illustration of the importance of economising our waste produces.
In lieu of long and extensive flues, condensers of various descriptions have fiom
time to time been introduced, but in most instances the former have been found to be
more efiicient
When, however, water can be procured for the purpose of cooling the condenseis
excellent results are generally obtained. — J. A P.
See Litharge, Minium, or Red Lead, Solder, Sugab or AceiaU op Lsais Ttfb
Metal, and White Lead.
LEAD ORES, ASSAY OF. The ores of lead may be divided into two classes.
The first class comprehends all the ores of lead which contain neither sulphur
nor arsenic, or in which they are present in smaU proportion only.
The second class comprises galena, together with all lead ores oontaming sulphur,
arsenic, or their acids.
From the facility with which this metal is volatilised when strongly heated, it is
necessary to conduct the assay of its ores at a moderate temperature.
A common wind furnace is best adapted for making lead assays. For this pnrpoie
the cavity for the reception of fliel should be 9 inches square, and the height of the
flue-way from the. fire-bars about 14 inches. For ordinary ores a fhmace 8 inches
square and 12 inches deep will be found sufficient ; but as it is easy to regulate, by a
damper, the heat of the larger apparatus, it is often found advantageous to be able to
produce a high temperature.
A furnace of this kind should be connected with a chimney of at least twenty £9et
in height, and be supplied with good coke, broken into pieces of the sixe of eggs;.
OuES OF THE First Class. — The assay of ores of this class is a simple opera-
tion, care being only required that a sufficient amount of carbonaceous matter be
added to effect ue reduction of the metal, whilst such fluxes are supplied as will affcntl
a readily-fusible slag.
When the sample has been properly reduced in size, 400 graiuA are weighed oat
and well mixed with 600 grains of carbonate of soda, and fh>m 40 to 60 grains of
finely •powdered charcoal, according to the richness of the mineral operated on.
This is introduced into an earthen crucible, of such a size as not to be more than
one-half filled by the mixture, and on the top is placed a thin layer of common salt.
The crucible is then placed in the furnace and gently heated, care being taken to so
moderate the temperature, that the mixture of ore and flux, which soon begins to
soften and enter into ebullition, may not swell up and flow over. If the action in tha
crucible becomes too strong, it must be checked by removal firom the fire, or by a
due regulation of the heat by means of a damper. When the action has subsided, the
temperature is again raised for a few minutes, and the assay completed. During the
process of reduction, the heat should not exceed dull redness ; but in order to com-
plete the operation, and render the slag sufficiently liquid, the temperature should be
raised to bright redness.
When the contents have been reduced to a state of tranquil fusion, the crucible
must be removed from the fire and the assay either rapidly poured, or, after being
tapped against some hard body to collect the lead in a single globule, be set to oooL
LEAD ORES, ASSAY OF. 671
When the operation has heen saocetsfolly conducted, the cooled alag will present a
smooth concaTe surface, with a Titfeoos lustre. When cold the crucible may be
broken, and the button extracted. To remove from it the particles of adhering slag,
it is hammered on an anvil, and afterwards rubbed with a hard brush.
Instead of employing carbonate of soda and powdered charcoal, the ore may be
fiised with 1 J times its weight of black flux, and the mixture covered by a thin layer
of borax.
Good results are also obtained by mixing together 400 grains of ore with an equal
weight of carbonate of soda and half that quantity of crude tartar. These ingredients,
after being well incorporated, are placed in a crucible, and slightly covered by a layer
of borax.
Each of the forgoing methods yields good results, and affords slags retaining but a
■mall proportion of lead.
Ores of thb Second Clabs, — This class comprehends galena, which is the most
common and abundant ore of lead, and also comprises suodry metallurgic product!, as
well as the sulphates, phosphates, and arseniates of lead.
GaUna, ^- The assay of this ore is variously conducted ; but one of the following
methods is usually employed for commercial purposes.
Fusion with an alkaunejlux, — This operation is conducted in an earthen crucible
which is to be kept uncovered until its contents are reduced to a state of perfect fusion.
The powdered ore, after being mixed with three times its weight of carbonate of
soda and 10 per cent of finely pulverised charcoal, is slowly heated in an ordinary
assay furnace until the mixture has become perfectly liquid, when the pot is removed
from the fire, and, after having been gently tapped, to collect any globules of metal
held in suspension in the slag, is put aside to cool. When sufficiently cold, the crucible
is broken, and a button of metallic lead will be found at the bottom : this must be
cleansed and weighed.
In place of carbonate of soda, pearlash may be employed, or the fusion may be
effected with black flux alone. When the last-named substance is used a somewhat
longer time is necessary for the complete fusion of the assay. Each 100 parts of
pure galena will by this method afford from 74 to 76 parts of lead.
Some of the old assayers were in the habit of first driving off the sulphur by roasting,
and afterwards reducing the resulting oxide with about its own weight of black flux.
This method, from the great fusibility of the compounds of lead, requires very
careful management, and at best the results obtained are unsatisfactory. Pure galena
by this method can rarely be made to yield more than 70 per cent of lead.
Fusion with metallic iron, — Mix the ore to be assayed with twice its weight of
carbonate of soda, and, after having placed it in an earthen crucible, of which it should
occupy about one half the capacity, insert with their heads downward three or four
tenpenny nails, and press the mixture firmly around them. On the top place a thin
layer of borax, which should be again covered with a little common salt The whole
is now introduced into the ftimace and gradually heated to redness ; at the expiration
of ten minutes the temperature is increased to bright redness, when the fluxes will be
fused and present a perfectly smooth surfkce. When this has taken place, the pot is
removed from the fire, and the nails are separatelv withdrawn by the use of a small
pair of tODgs, care being taken to weU cleanse each in the fluid slag until flree from
adhering lead. When Ae nails have been thus removed, the pot is gently shaken, to
collect Uie metal into one button, and laid aside to cool i idfter which it may be broken,
and the button removed.
Instead of first allowing the slags to cool and then breaking the crucible, the assay
may, if preferred, after the withdrawal of the nails, be poured into a mould.
Assay in an iron pot — Instead of adding metallic iron to the mixture of ore and
flux, it is generally better that the pot itself should be made of that metaL
For this purpose, a piece of half-inch plate-iron is turned up in the form of a cru-
cible and carefully welded at the edges. The bottom is closed by a thick iron rivet,
which is securely welded to the sides, and the whole then finished on a properly
formed mandriL To make an assay in a crucible of this kind, it is first heated to
dull redness, and, when sufficiently hot, the powdered ore, intimately mixed with its
own weight of carbonate of soda, half its weight of pearlash, and a quarter of its
weight of crude tartar, is introduced by means of a copper scoop. On the top of the
^hole is placed a thin layer of borax, whilst the crucible, which, for the ready intro-
duction of Uie mixture, has been removed f^m the fire, is at once replaced. The
heat is now raised to redness, the contents gradually becoming liquid and giving off
large quantities of gas. At the expiration of Arom eight to ten minutes the mixture
will be in a state of complete fosion ; the pot is now partially removed from the fire,
and its contents briskly stirred with a small iron rod. Any matter adhering to its
sides is also scraped to the bottom of the pot, which after being again placed m a hot
part of the furnace is heated duriog three or four minutes to bright redness.
672
LEAD.
The crucible is then seised by a strong pair of bent tongs, on that part of the edge
which is opposite the lip, and its contents rapid-lj poared into a cast iron mould.
The sides of tiie pot are now carefully scraped dowu with a chisel-edge bar of iron,
and the adhering particles of metallic lead added to the portion first obtained. When
sufficiently cool«l the contents of the mould are easily removed, aud the button of
lead cleaned and weighed. By this process pure galena yields 84 per cent of metallic
lead, free from any injurious amount of iron, and perfectly ductile and malleable.
This method of assaying is that adopted in almost all lead-smelting establishments,
and has the advantage of affording good results with all the ores belonging to the
second class.
Assay in the iron dish. — In some of the mining districts of Wales, the assay of
lead ore is conducted in a manner somewhat different to that just described. Instead
of fusing the ore in an iron crucible with carbonate of soda, pearlash, tartar and
borax, £e fusion is effected in a flat iron dish, without the admixture of any sort of
finx:-> J. A. P.
Number of Lead Mines, Quantities, and total Value of Ore raised and ofmetaOie Lead
produced therefrom, in each County in JErigland, Wales, Scotland, and Irdand^ ta each
of the Years 1856, 1857, and 1858.
England.
NumbcfroTMiDa.
LcMlOre.
Meullic Lnd fkom Ok i^Md
ia aadi Coon^.
IS56.
IR57.
1858.
1856.
1857.
1858.
1856.
lftS7.
1S5«.
Tom.
Tom.
Tom.
Tom.
Tooo.
T^
Cornwall . . -
42
42
35
9,973
9,560
9,710
6,597
6.036
5.4%
Devonshire - - -
14
15
12
8,I3S
2,''90
2,779
2.000
1,586
i,e&5
Cumberland
73
81
76
7^11
6,450
7,235
5,321
4,711
5.tt7
Durham and Northum.
berland - - -
34
35
36
24,125
21,580
19.999
17,674
17.073
16,776
Westmoreland -
11
11
6
2,923
2,798
2,190
2.179
2,103
1,673
Derbjshire - - >
.
«
*
9,524
9,233
10.466
6,261
6,061
6.277
Shropshire . • •
9
14
14
4,407
3.350
3.994
8,228
2.561
2.'«3
Yorkshire - * -
14
14
14
12,174
12,406
11,480
8,986
7,876
7,605
Somersetshire
Total - -
Wales.
I
198
6
218
5
198
750
485
1,000
600
Ml
4S5
74,325
68,452
68,863
52.746
48.908
48,100
Cardiganshire
47
51
30
8,500
7,573
7.086
6,191
5,510
.V440
Carmarthenshire
3
2
3
1.280
1,081
1,328
932
776
9S4
Denbighshire
3
7
10
8.103
4,181
4,749
2.367
8.241
3.7^
Flintshire . - .
48
48
34
4,607
8,006
8,696
8,518
3.281
8.K39
Montgomeryshire
12
14
14
1.723
2,389
1,975
1,849
1.889
I.«5
Merionethshire -
7
8
6
849
332
826
266
250
944
Radnorshire . - .
S
2
2
12
lOij
102
8
81
76
Caernarvonshire -
Total
IsLB OF Man
Scotland.
3
124
4
10
142
A
9
237
442
289
163
821
S02
107
19,871
19,112
19,675
14,789
14,299
14,661
4
8.217
2,656
-
2,450
2,028
Argrleshlre ...
Kirkcudbrighuhire -
Lanarkshire
Dumfriesshire
Perthshire ...
Total - -
IRBLAND.
2
4
1
1
1
9
I
4
2
1
1
9
I
6
2
1
1
148
820
625
808
130
61
239
6H9
850
61
44
235
1,087
870
54
109
S52
855
606
94
89
173
466
640
42
84
166
717
690
37
11
1.931
1,890
2,290
1,416
1.850
1,885
•
Armagh - . -
Clare - - - -
-
1
1
4
-
30
69
40
■ m
21
42
25
Down ....
1
1
I
602
458
323
430
863
942
Wicklow - - -
Galway - - -
2
2
2
1
1.520
1,653
2,054
938
915
1.817
Donegal ...
*
1
Kerry - - . -
Monaghan ...
^
1
a
1
Cork - . - -
Waterford . - -
Total - .
Sundries under 10 tons
1
8
7
3
7
1
8
60
811
162
84
82
206
107
54
15
2.4ft8
2,298
3.603
1.601
1.406
1,704.
.
170
67
93
127
48
70
Total
342
381
835 <
101,997
94.475
95,938
73,139
67.439
67.979
Ettim^iid Valne.
£
£
£
£
£
£
l-
1.431,609
1.893,506
1,466.646
1,755,096
1.483.656
1,489,006
LEAD. 673
LEAD-SHOT. (PEomft de ChatsBy Fr. ; Schrot, FUnten^hroi, GeroL) The origin
of most of the imperfections in the manafiicture of lead-sbot is the too rapid cooling
of the spherules by their bein^ dropped too hot into the water, whereby their surfaces
form a solid -crust, while their interior remains fluid, and in its subsequent concretions,
shrinks, so as to produce the irregularities of the shot
The patent shot towers originally constructed in England ohviate this evil hy ex-
posing the fused spherules after they pass through the cullender, to a large body of
air during their descent into the water tub placed on the ground. The highest erec*
lion of this kind is prohably at Villach in Carinthia, heing 240 Vienna, or 249 English
feet high.
The quantity of arsenic added to the mass of melted lead varies according to the
quality of this metal ; the harder and less ductile the lead is, the more arsenic must
be added. About 3 pounds of either white arsenic or orpiment is enough for one
thousand parts of soft lead, and about 8 for the coarser kinds. The latter are em-
ployed preferably for shot, as they are cheaper and answer sufficiently well. The
arsenical alloy is made either by introducing some of this substance at each melting ;
or by making a quantity of the compound considerably stron^r at once, and adding
a certain portion of this to each charge of lead. If the particles of the shot appear
lens-shaped, it is a proof that the proportion of arsenic has been too great ; but
if they are flattened upon one side, if they are hollowed in their middle, called
Cupping by the workmen, or drag with a tail behind them, the proportion of arsenic is
too smalL
The following is the process prescribed by the patentees, Ackerman and Martin.
Melt a ton of soft lead, and sprinkle round its sides in the iron pot about two shovel*
Alls of wood ashes, taking care to leave the centre clear ; then put into the middle
about 40 pounds of arsenic to form a rich alloy with the lead. Cover the pot with
an iron lid, and lute the joints quickly with loam or mortar to confine the arsenical
vapours, keeping up a moderate fire to maintain the mixture fluid for three or four
hours; after which skim carefully, and run the alloy into moulds to form ingots or pigs^
The composition thus made is to be put in the proportion of one pig or ingot into 1000
pounds of melted ordinary lead. When the whole is well combined, take a perforated
skimmer, and let a few drops of it fall from some height into a tub of water. If they
do not appear globular, some more arsenical alloy must be added.
Lead which contains a good deal of pewter or tin must be rejected, because it tends
to produce elongated drops or tuls.
From two to three tons are usually melted at once in the large establishments. The
surface of the lead gets covered with a crust of oxide of a white spongy nature, some-
times called cream by the workmen, which is of use to coat oyer the bottom of the cul-
lender, because without such a bed the heavy melted lead would run too rapidly through
the holes for the granulating process, and would form oblong spheroids. The mount-
ing of this filter, or lining of the cullender, is reckoned to be a nice operation by the
workmen, and is regarded usually as a valuable secret.
The cullenders are hollow hemispheres of sheet iron, about 10 inches in diameter,
perforated with holes, which should be perfectly round and tree from burs. These
must be of an uniform sixe in each cullender ; but of course a series of different cul«
lenders with sorted holes for every different size of lead- shot must be prepared. The
holes have nearly the following diameters for the annexed numbers of shot
No. 0. - - - - - - ^ of an inch.
1. A
2. h
3. -----"*{ n
4. - ' - - - - 50 *»
From No. 5. to No. 9. the diameter decreases by regular gradations, the latter being
only ^ of au inch.
The operation is always carried on with three cullenders at a time ; which are sup-
ported upon projecting grates of a kind of chafing dish made of sheet iron somewhat
like a triangle. This chafing dish should be placed immediately above the fall ; while
at its bottom there must be a tub half filled with water for receiving the granulated lead.
The cullenders are not in contact, but must be parted by burning charcoal in order to
keep the lead constantly at the proper temperature, and to prevent its solidifying in the
filter. The temperature of the lead bath should vary with the size of the shot; for the
largest, it should be such that a bit of straw plunged into it will be scarcely browned,
but for all it should be nicely regulated. The height from which the particles should
be let fall varies likewise with the size of the shot; as the congelation is the more
rapid, the smaller they are. With a fall of 33 yards or 100 feet, from No. 4 to Na 9
may be made: bat for larger sizes, 150 feet of height will be required.
Vol. IL XX
674 LEATHER.
Eyerythlng being arranged as abore described, ttie workman puts the fi]fter-«tsiF
into the cullender, pressing it well against the sides. He next pours lead into it with
an iron ladle, but not in too great quantity at a time, lest it shoald run through too
fast The shot thereby formed and found in the tub are not all equaL
The centre of the cullender being less hot affords larger shot than the sides, which
are constantly surrounded with burning charcoal Occasionally, also, the three cul-
lenders employed together may have holes of different sizes, in which case the tab
may contain shot of very Tarious magnitudes. These are separated from each other
by square sieves of different fineness, 10 inches broad and 16 inches long, their bottoms
being of sheet iron pierced with holes of the same diameters as those of the cullenders.
These sieves are suspended by means of two bands above boxes for receiving the
shot ; one sieve being usually set above another in consecutive numbers, for instance,
1 and 2. The shot being put into the upper sieve, No. 0 will remain in it ; No. 1 will
remain in the lower sieve, and No. 2 will, with all the others, pass through it into the
chest below. It is obvious that by substituting sieves of successive fineness, shot of
any dimensions may be sorted.
In the preceding process the shot has been sorted to size ; it must next be sorted to
form, seas to separate all the spheroids which are not truly round, or are defective in
any respect For this purpose a board is made use of about 27 inches long and 16
broad, furnished partially with upright ledges ; upon this tray a handful or two of the
shot to be sorted being laid, it is inclined very slightly, and gently shaken in the hori-
lontal direction, when the globalar particles run down by one edge, into a chest set
to receive them, while those of irregular forms remain on the sides of the tray, and
are reserved to be re-melted.
After being sorted in this way, the shot requires still to be smoothed and polished
bright This object is effected by putting it into a small octagonal cask, through a
door in its side, turning upon a horizontal iron axis, with rests in plommer box@ at its
ends, and is made to revolve by any mechanical power. A certain quantity of plumbago
or black lead is put in along with the shot
LEAD, CARBONATE OF. See Whitb Lead.
LEAD, NITRATE OF (Nitrate de ^omb, Fr.; Salpetersawres bUicayd, GcTm.\
IB made by saturating somewhat dilute nitric acid with oxide of lead (litharge), eva-
porating the neutral solution till a pellicle appears, and then exposing it in a hoi
chamber till it be converted into crystals, which are sometimes transparent, but gene-
rally opaque white octahedrons. Their spec. grav. is 4*068 ; they have a cooling,
sweetish, pungent taste. They dissolve in 7 parts of cold, and in much less boiling
water ; they fuse at a moderate elevation of temperature, emit oxygen gas. and pass
into oxide of lead. Their constituents are 67*3 oxide and 32 7 acid. Nitrate of lead
IS much employed in the chrome yellow style of Calico-printing ; which see.
There are three other compounds of nitric acid and lead oxide ; viz. the bi-basic,
the tri-basic, and the se-bcuic ; which contain respectively 2, 3, and 6 atoms <^ base to
1 of acid.
LEAD, OXICHLORIDE OF. A white pigment patented by Mr. Hugh Lee Pat-
ttnson of Newcastle, which he prepares by precipitating a solution of chloride of lead
in hot water with pure lime water, in equal measures ; the mixture being made with
agitation. ^ As the operation of mixing the lime water, and the solution of chloride of
lead, requires to be performed in an instantaneous manner, the patentee prefers to
employ for this purpose two tumbling boxes of about 16 teei cubic capacity, which
are charged with the two liquids, and simultaneously upset into a cistern in which
oxichloride of lead is instantaneously formed, and from which Uie mixture flows into
other cisterns, where the oxichloride subsides. This white pigment consists of one
atom of chloride of lead and one atom oxide of lead, with or without an atom of water.
LEAD, SALTS OR The salts of lead; beyond those already named, which enter
into any of our manufactures, are few and unimportant Ure^M Dietumtuy of Ou*
mistry should be consulted for them.
LBATHER, (Cuir, Fr.; Leder, Germ.; Leer, Dutch; Lteder, Danish; LSder,
Swedish ; Cuojo^ Italian ; Cuero, Spanish ; Kusha, Russian.) This substance coxk"
sists of the skins of animals chemically changed by the process called tejuttnf.
Throughout the civilised world, and from the most ancient times this substance has
been employed by man for a variety of purposes. Barbarous and savage tribes osi»
the skins of beasts as skinsf civilised man renders the same substance unalterable by
the external agents which tend to decompose it in its natural state, and by a variety
of peculiar manipulations prepares it for almost innumerable applications.
Although the preparation of this valuable substance in a rude manner has bees
known from the most ancient times, it was not until the end of the last, and the be-
ginning of the present century (1800) that it began to be manufactured upon right
principles, in consequence of the researches of Macbride, Deyeuz, Scguin, and Davy.
LEATHER. 675
SkJDi ma; be convRted into leslher either ulth or withont their hair ; generally,
hoacTer, the bur is removed.
The atott imporlanl aod cotijy kind* tre camprlied ander sole leUher tknd upper
tenlher, to which may be kdded hamees leather, belti used In machinery', leather
hoae^ ftc, but u Tar aa the turner ia concerned, the«e are compreheDded ahnogt en-
tirely in the kioda known as upper leather.
The active principle by vhieh the tkma of animaU are prevented fVom putrefying,
and at the tame time, under loine mode) of preparation, rendered cumparativelj Im-
pervioui to water, ia e&lled tannia, or tannic acid, a properly found in the bark of Che
various ipeciei of Quercoi, but npeclally plentiful in the gall-nnt. When obtained
pare, ai it may easily be from the gall-nut, by chemical meaai, tannic acid appear* ai
s ilighliy yellowiih, almoat a eolourleu man, readily soluble In water ; It prroipitatea
gelaiin from solution, forming what has been called tanHogtlatin, Tannic acid also
precipitates albameu and starch. There can be little difficulty, after knowing the
chemical combination just alluded to, in understanding (he pGCnliar and striking
change produced on animal subtlance in the formation of leather. The hide or skin
eonsials principally of gelatin, for which the vegelaMc astringent tannin has an
affinity, and the chemical unlun of these substances In the proceM of tanning pro-
dace* the useful article of which we are treating.
Before entering npon the various processes by which the change* are effected on
the animal fibre, it may not bo uninteresting to speak of some of the principal as-
tringents n*ed (br the purpose of producing these effect*.
BarK obtained from the osk-tree is the most valuable and the meet extensively Died
ingredient in tanning, and for a long time no other substance was used in England
for the purpose. In consequence of the demgmd having hecoine very much greater
than the supply, and ihe consequent increase in the prico of the article, it became
necesaary to investigate its properties, In order, if po.'*ible, to famish the required
quantity of tanning matter from other sources. Among other substitutes which
were tried with lome success In other countries may be mentioned heath, nyrlli
kamt, tciU lawii leavti, birch-lru bark, and (according to the PtKni/ Cychpadxa) in
IT6.^ oak sawdust was applied in E^ngland, and has since been used in Germany for
this purpose.
InTettigalkin proved that the tanning power of oatc bark consisted in a peculiar
astringent property, to which the name of tannin has been given, and this discovery
■ngge*ted that other bodies postering this property would be suitable subatitute*.
According to Sir U. Dnvy tbe following proportions of tannin in Ihe different sob.
stances mentioned will be found: — "S^lbs. of oak bark are equal to 2^ lbs. of galls,
lo3lb*.ofBumach,to7ilbs.ofbarkofLeiceEter willow, to 11 lb*, of the bark of the
Spanish chestnat, to IB lb*, of elm bark, and to SI lb*, of common willow bark." —
Penny Cychpadia.
Oak bark contain* more taanin when cut in spring by four and a half time*,
than when cut in winter; It is also more plentifal in young trees than in old ones.
About 40,00OtoD> of oak birk are said to be imported into this country annually,
fWim the Netherlands, Germany, and port* in the Mediterranean. The quantity of
English oak bark used we have no means of ascertaining. It is prepared for use by
grinding it to a coarse powder between cast iron cylinders, and laid into the tanpil*
alternately with Ihe skins to be (anncd. Sometime*, however, as will be hi'reallcr
noticed, an infusion of tbe bark in water Is employed with better effect.
Mimosa. — The bark and podt of *everal kind* of Pro*opi*, the astringent properties
of wMcb have rendered tbem valoable In tanning, are known in commerce h; tbi*
1104 1105
676 LEATHER.
belong to tbi* divl^o. The propoiii is fonncl in India and Soath America ; the g«Bn
coniisu both of ihruba nnd trees.
ViLOM^ — The oak i*hich produce* Ihia Hoorn is the Qatreiu Mgilop$, or gnat
prtckl; cupped oiik (^gt. 110-1, 1105). These are exported from Ihe Horea and Le-
vant ; the husli cont&ius nbundance of tannin.
CiTECBU, or Terra Japonica, a tbe inspiuated extract of the Acacia ealrcha. At
the time the aap is most perfectly fonned the bark of the plant is taken off, the tree a
then fi'lled, and the outer part remoTed ; the heart of the tree, vhich is brovn. is cat
into pieces and boiled ID water ; when sufficientlj boiled it is placed in the sun. mad,
snbject to Tariaus mBnipulstioos, gndvaXij dried. It is cut into square pieces, sud
much resembles a main of earth ia appearance ; indeed it was once coosidered to be
Nch. henCQ the Dame Terra Japonica.
We give Sir U. Davy's analysis ; the first nombers represent Bombay, the aeeood
Ben^ catechu : —
Tannin 109 - - 97
Extractive ..---. 68 --73
Mucilage - - - - • -13- -16
Impniiiies - - - - - -10- -14
This astringent is also obtmined from the Unearia Oamhir.
DrvmrTt is a leguminous plant of the genus Ca;sa]piaia, C, corinHa. The legmnea
of this species are extremely astringent, nod contain a very large quantity of tannic
jjQg and gallic acid, they gnnr in a
very peculiar manner, and became
curiouily curled as they arrive to
perfectioiL The plant is a native
of America, between the Xrofia.
Fiy. 1106. _
SiTMAcH is a plant belonging (o
the genua Rhus ; several of the
^_ species hnyeaBtringentpri^jeoiesi
i'j^. . Rhiu colinuM and Rliia cariajia
1 are much used in tanniog; the
■rt- hark of the latter is said to be the
'"-£: only ingredient osed in Turkey
'= — 1.^--^---.. ji^— .T'— for the purpose of conterting
gelatin into leather. That n»d
in ibis country is f^und to a fine powder, and is extensively applied to the prodoctirai
of bright leather, both by tanners and curriers.
Many olher vegetable products have been troia time to time proposed, and to some
extent adopted for ihe same end, but they need not be cnnmerated.
The process Gr^t attended to by the tanner is simply to soak the skin or bide in
water i those from the borne market may be said to be washed merely, as they remain
in water only a few hours; while bides imported from foreign countries, and wbifh
hate been preserved by sailing or drying, and tapeciallf die latler, require soaking for
a longer period, io order to render them supple, and beating oT rubbing materially
assists in bringing them to the required condition.
After removing the hams, the softened or recent bides are laid in aheap for a short
time, after which they are suspended on poles in a close room called a smoke-honse,
heated somewhat above the common temperature by a smouldering fire. In these
circumstances, a slight putrefaction superveues, which loosens the epidermis, and
renders the hair easily detachable. This meihort for removing the hair is by no means
general in this country. The plan adopted is to place the hides in a large vat or
Eit, containing milk of lime, in which they mn>t be moved f^quently, to aJlow the
me to act equally on every part. When the menslnium has taken proper effect, the
hair is ensily removed, and for this purpose Ihe bide is spread out, and a Hunt tool
is worked over tlie surface. The hair being removed, ibe hide is washed in walcrto
cleanse it fW)m the lime, which most be most thoroughly effected.
The heaviest hides are lor the most part tanned for sole leather, and as the Ihiimer
Esrlsare cut off previous to their being prepared for sale, they have received the name of
utlt or backt : tbe various processes through which these pass will be first descrilied.
After removing tbe hair and wnshing, the hidi^s are placed on a conicx beam (_Jig,
1107 ), and worked with a cuncave tnol with two handles (jtj. 1 108), in order to remove
any flesh or fatty mailer which may adhere to them ; this being done they are worker,
on the same beam, on the grain side, to drive out Ihe grease and remove any remaining
hair. Tiie^eahingi are pressed into cnkei nnd sold for making glue, as are all such
portions of the hide or skin as cannot be conveniently worked. The hair is sold to
plasterers, to be used in their mortar ; and the tails, also for tbe hair, to sob-maken
and others requiring snch mslerial*
LEATHER.
671
' Sach hidMutKdMigned for machinerj purposes in neit iinmeried in apilcoD-
UiDiDg vBier impregDBted wiih tulphurk acid, lli« acid Tftryiog from g^ to ^ of tha
miitare. Tbii process is HO^
called mitiiig, beCHnM il dis<
tends the pores, and makea
tb* fibrei swell, so as lo be-
come more (luceptible of the
Be lion of taanipg infiuions,
Forly'tlglit hours in general
suffice (or this operation, bat
more time may he safelj taken.
From the tenn railing it will
be concluded that the siih- --"
•tance of the hide is [ncreased, ^- -"~-
and this is the fact i but as ~--~J,'- ^^ ^
the gelatine it not increased "'" " -C , -rr-iT'^,^--' ' "
il is said that the iboemakeT'i
hammer irould coadense the *
leuther so mach that it ironid
lose any supposed advantage .
arising out of this increase '" *
thickness. There is, howerer,
a method uf augmeuting the suhstanee of sole leather called paging, wliicli, vlica once
communicated, appears to exist pennsnenlly i the procees is known to n sinalt exteat
only, and the material is said to be considerably injured by this mode of preparation.
When the hides are sufficiently raiad, ther are iranaferred lo a pit supplied with s
veak infusion of bark ; here they are bandiei, at first several limes a day, that is, (hey
are drawn out of the pits, or moved np and down in the liipior, lo prevent the grain
from being drawn inio wrinkles. As the oote, or tanning iafusion, takes effect, Ihey
are put into pils eontaiuing stronger liquors, and after a moatb or six weeks they are
placed in a pit, in which tbey are stratified with oak bark, ground by a proper mill
into a coarse powder. The pit is then filled with an infusion of bark. Id a month
or flie weeks the tanning and extractive matter of the bark will have intimately
combined with the animal fibre -, tbe pit, exhausted of its Tirlue, must be renewed by
taking out the spent bnrk and repeating the dose as in the Grat instance. The hides,
which were placed at the top of the pit at first, are now put into the boltom, to equa-
lise the action. In about three months this also is spent, and tbe process beinjc
repeated two or three times more the operation is complete. The bides are now re-
moved from the pit, and hung np in a shed. In tbe progress of drying they are com-
pressed with a steel tool, and afterwards they sre subjected to tlie actino of a brats
roller. The steel tool is called a ;ifn ; it is of a triangular shape ifig. 1 lD9),with the sides
scooped oal^. 1110), presenting ^iree blunt edges. The butt is thrown across a pole.
T"*^
and the workman taking the pin by the handles a, a{^. UOO), presses il forcibly over
the (train side of the leather ; after carefully compressing every part in Ihia way, the
bull ii laid upon a flat bed of solid wood-work, prepared for the purpose, and (be brasa
roller it worked backward and forward until every portion is sufficiently compressed
(jfig. IIU). The njlera is a cylinder varyiog from 9 to 12 inches in length, and ftam
678 LEATHER.
7 to 10 iDclies in diBmeter ; & is an open box over tbe roller, ioto wbich weiglitf are
placed to make the necessary pressure, ten or twelve cwt. being frequently oaed for
tbe pnrpose ; c, c, forms a fulcrum for lifting tbe roller from tbe bed to the leather ;
d is tbe handle by which tbe machine is worked. When tbe compresaion ia eom-
pleted, tbe only thing remaining to be done is properly to dry tbe leather, and then it
is fit for the market.
Some manufacturers place on tbe bottom of the tan pit five or six inches of spent
bark, and two or three inches of fresh bark over it, then a hide, and so alternately
bark and a hide, until the pit is nearly fbll, reserving a small space at the top for a
thicker layer of bark, over which weighted boards are laid, to condense the whole
down into the tanning infusion.
The operation of tanning sole leather by the above method occupies a year or more,
the time depending on the nature and stoutness of the hide.
A perfect leather is recognised by its section, which should bare a glistening
marbled appearance, without any white streak in the middle.
Crop hides are manufactured very much like butts, that is to say, they are placed
in milk of lime until the hair is sufficiently loosened, equality of action being secured
by occasionally moving them in tbe menstruum ; they are then cleared of the hair and
other impurities by thejleshing knife, worked on tbe convex beam already described,
they are then freed from lime by thorough washing. The next process is to plunge
them into a weak ooze, from which they are transferred to other pits with stronger
ooze ; all tbe while they are frequently handied, that is, moved up and down in the
infusion. After a month or six weeks they are subjected to a mixture of ground oak
bark and stronger ooze in other pits, to a series of which they are progressiTely sub-
jected during two or three months.
The hides are next put into large vats called ktjfers, in which they are smoothly
stratified, with more bark and a stronger infusion. After about six weeks they are
taken out of these vats, and subjected to a new charge of this material, and allowed
to lay some two months ; this process is repeated once or twice more till the hides
are thoroughly tanned. They are then slowly dried in tbe shed, and folded for
market. Although in general the stoutest and most compact hides are used as sole
leather (notwithstanding that they have not been condensed by the tanner, as in the
case of butts), yet many are appropriated to other purposes by the currier, and the
lighter cow hides are manufactured for the upper leather of stout ahoes, water
boots, &c.
The process of tanning skins (as calves, seals, &c.) next claims attention. These
are placed in the lime pits until the hair can be easily removed, a process which
rcqutres about ten or twelve days ; this being accomplished, they are next washed in
water so as completely to remove the lime, as far as washing can secure its removal,
and then immersed in a lixivium of pigeon's dung, dog*s dung, or matters of a like
nature ; in this state they remain about ten or twelve days, the state of the atmo-
sphere rendering; the process quicker at one time than another ; here also they are
frequently handled, and worked on both sides on the convex beam. The working,
joined to the action of the peculiar lixivium, serves to separate the remaining lime,
oil, and glutinous matter, and at the same time to render the skin pliant, soft, and
ready to imbibe the tanning principle. It is important that great attention ahould be
paid to the process just described, as too short a period would produce a hard and
crisp leather, while a few hours more than is necessary makes the article coarse and
spongy, both of which conditions should be very carefully guarded against
The skins are next removed to a pit containing a weak solution of bark, in which
they undergo nearly the same treatment as crop hides, but they are not commonly
stratified in the layers. About three months is usually occupied in tanning calfskins,
but of course tbe stouter the skin the more will be the time required. When dried
thej are disposed of to the currier, who dresses them for the upper leathers of boots,
shoes, and a variety of other purposes. It is not unusual for the. lighter cow hides to
be treated like calfskins.
Horse bides are also treated like calfskins ; but as the horse hide, with the exception
of the part on and near tbe animal's rump, produces a thin leather, it is usual, before
subjecting the hide to the action of the bark, to cut out what is called tbe Imti, which
is tanned separately, and frequently used as an inferior sole leather. It is also to be
remarked that horse hides and kips (the hides of small foreign cattle) are frequently
subjected to a process called bate shaving, in which the stout parts are reduced by a
currier* s knife previous to tanning, tbe object being to secure the complete infiltration
of the animal fibre by the tannin in every part of tbe hide in the same time.
Sheepskins are usually pressed after the wool is removed, and before the tanning
process is commenced, to get rid of the fatty matter contained in them, and which is
not readily removed by ordinary working.
LEATHER. 679
In all the above processes, as the animal fibres on the sarfaoe of the skin absorb
most readily the tanning principles, and thereby obfftmct, in a certain degree, their
passage into the interior fibres, especially of thick hides, it becomes an object of im-
portance to contrive some method of overcoming that obstacle, and promoting the
penetration of the tan. The first manufacturer who appears to have employed effica*
cioos mechanical means of favouring the chemical action was Francis 6. Spilsbnry,
who in April, 1823, obtained a patent for the following operation : — After the hides
are freed from the hairs, &e. in the usual way, they are minutely fnspected as to their
Miundness, and if any holes be fbund, they are carefully sewed op, so as to be water
tight Three frames of wood are provided of equal dimensions, fitted to each other,
with the edges of the frames held together by screw bolts. A skin about to be tanned
is now laid upon the frame, and stretched over its edges, then the second frame is to
be placed upon it, so that the edges of the two frames may pinch the ekin all round
and hold it securely; another such skin is then stretched over the upper surface of the
second fi-ame, in like manner, and a third fVame being set upon this, confines the
second skin. The three frames are then pinched tightly together by a series of screw
bolts, passing through ears set round their outer edges, which fix the skin in a proper
manner for being operated upon by the tanning liquor.
A space has been thus formed between the two skins, into which, when the frames
are set upright, the infusion is introduced by means of a pipe from the cistern above,
while the air is permitted to escape by a stopcock below. This cock must of course
be shut whenever the bag is filled, but the one above is left open to maintain a
communication with the liquor cistern, and to allow the hydrostatic pressure
to force the liquor through the cutaneous pores by a slow infiltration, and thus
to bring the tannin into contact with all the fibres indiscriminately. The action
of this pressure is evinced by a constant perspiration on the outer surfaces of the
skins.
When the tanning is completed, the upper stopcock is closed, and the under is
opened to run ofiT the liquor. The frames are now removed, the bolts are unscrewed,
and the pinched edges of the skins pared off ; aitec which they are to be dried and
finished m the usual manner.
A modification of this ingenious and efiectnal process was made the subject of a
patent, by William Drake, of Bedminster, tanner, in October, 1831. The hides, after
the usual preparatory processes, are immersed in a weak tan liquor, and by frequent
handling or turning over, receive an incipient tanning before being submitted to the
infiltration plan. Two hides, as nearly of the same sise and shape as possible, are placed
grain to grain, when their corresponding edges are sewed firmly together all round
by shoemaker's waxed thread, so as to form a bag sufficiently tight to hold tan liquor.
This bag must then be suspended by means of loops sewed to its shoulder end, upon
pegs, in such a manner that it may hang within a wooden-barred rack, and be confined
laterally into a.book form. About an inch of the bag is left unsewed at the upper end,
for the purpose of introducing a fhnnel through which the cold tan liquor is poured
into the bag till it be full. After a certain interval, which varies with the quality of
the hides, the outer surface becomes moist, and drops begin to form at the bottom of
the bag. These are received in a proper Tcssel, and when they accumulate sufficiently
may be poured back into the funnel ; the bag being thus, as well as by a fresh supply
from above, kept constantly distended.
When the hides are observed to feel hard and firm, while every part of them feels
equally damp, the air of the tanning apartment, having been always well ventilated, is
now to be heated by proper means to a temperature gradually increasing from 70^
to 150^ of Fahrenheit's scale. This heat is to be maintained till the hides become
firmer and harder In all parts. When they begin to assume a black appearance in some
parts, and when the tan liquor undergoes little diminution, the hides may be considered
to be tanned, and the bag may be emptied by cutting a few stitches at its bottom.
The outer edges being pared off, the hides are to be finished in the usual way. During
their suspension within the racks, the hides should be shifted a little sideways, to
prevent the formation of furrows by the bars, and to facilitate the equable action of
the liquor.
By this process the patentee says, that a hide may be tanned as completely in ten
days as it could be in ten months by the usual method.
Messrs. Knowlys and Duesbury obtained a patent in August, 1826, fbr accelerating
the impregnation of skins with tannin, by suspending them in a close vessel, A'om which
the air is to be extracted by an air pump, and then the tanning infusion is to be ad-
mitted. In this way, it is supposed to penetrate the hide so effectually as to tan it
uniformly in a short time.
Danish leather is made by tanning lamb and kid skins with willow bark, whence it
derives an agreeable smell. It is chiefiy worked up into gloves.
X X 4
680 J^ATHER.
Of the tawing or drusing of skins for ^ooes, eoid white Aeep leaAer.
The operations of this art are*. 1, washing the skins ; 2, properly treating them vith
lime ; 3, taking oflf the fleece; 4, treatment in the leather steep.
A shed erected upon the side of a stream, -with a cistern of water for washing the
skins ; wooden horses for cleaning them with the hack of the fleshing knife ; pincers
f(ir removing the fibres of damaged wool ; a plunger for depressing die skins in the
pits ; a lime pit ; a pole with a bag tied to the end of it ; a two-handled fleshing knife ;
a rolling pin, from 15 to 18 inches long, thickened in the middle. Such are some of the
utensils of a tawing establishment. There must be provided also a table for appljing
the oil to the skins ; a fulling mill, worked by a water-wheel or other power ; a dress-
ing peg ; a press for squeezing out the fatty filth ; a stove ; planks mounted apoa l^s,
for stretching the skins, &c.
Fresh skins must be worked immediately after being washed, and then dried, other-
wise they ferment, and contract either indelible spots, or get tender in certain points,
so as to open up and tear under the tools. When received in the dry state they shonld
be steeped in water for two days, and then treated as fresh skins. They are next
strongly rubbed on the convex horee-beam with a round-edged knife, in order to make
them pliant. The rongh parts are removed by the fleshing knife. One workman can
in this way prepare 200 skins in a day.
The flesh side of each being rubbed with a cold cream of lime, the skins are pikd
together with the woolly side of each pair outermost, and the flesh sides in contact
They are left in this state for a few days, till it is found that the wool may be easily
removed by plucking.
They are next washed in running water, to separate the greater part of the lime,
istripped of the wool by small spring tweezers, and then fleeced smooth by means of the
rolling-pin, or sometimes by rubbing with a whetstone. Unless they be fleeced soon
after the treatment with lime, they do not well admit of this operation subaeqaently, ss
they are apt to get hard.
They are now steeped in the milk of lime-pit, in order to swell, soften, and cleanse
them ; afterwards in a weak pit of old lime-water, from which they are taken oat and
drained. This steeping and draining upon inclined tables, are repeated frequently
during the space of 3 weeks. Only the skins of young animals, or those of inferior
value are tawed. Sometimes the wool is left on, as for housings, &c.
The skins, after having been well softened in the steeps; are rubbed on the outside
with a whetstone set in a wooden case with two handles, in order to smoothe them
completely by removing any remaining filaments of wool. I^mb skins are rubbed
with the pin in the direction of their breadth, to give them suppleness ; but sheep skins
are fulled with water alone. They are now ready for the branning, which is done by
mixing 40lbs. of bran with 20 gallons of water, and keeping them in this fermentable
mixture for three weeks — with the addition, if possible, of some old bran water. Here
they must be frequently turned over, and carefully watched, as it Is a delicate operation.
In the course of two days in summer, and eight in winter, the skins are said to be
raised, when they sink in the water. On coming out of the bran, they are ready
for the white stuff; which is a bath composed of alum and sea-salt Twelve, fourteen,
and sometimes eighteen pounds of alum for 100 skins, form the basis of the bath ; to
which two and a half pounds of salt are added in winter, and three in summer. These
ingredients are introduced into a copper with twelve gallons of water. The salt aids
in the whitening action. When the solution is about to boil, three gallons of it are
passed through the cullender into pi basin ; in this 26 skins are worked one after
another, and after draining, they are put together into the bath, and left in it for ten
minutes to imbibe the salts. They are now ready to receive the paste. For 100 skins,
from 13 to 15 pounds of wheat flour are used, along with the yolks of 50 eggs. AAer
having warmed the alum bath through which the skins have been passed, the flour is
dusted into it, with careful stirring. The paste is well kneaded by the gradual addition
of the solution, find passed through the cullender, whereby it becomes as clear as honey.
To this the yolks being added, the whole is incorporated with much manual labour.
The skins are worked one after another in this paste; and afterwards the whole toge-
ther are left immersed in it for a day. They are now stretched and dried upon poles,
in a proper apartment, during from 8 to 15 days, according to the season.
The effects of the paste are to whiten the skins, to soften them, and to protect them
f\rom the hardening influence of the atmosphere, which would naturally render them
brittle. They would not bear working upon the softening iron, but for the emulsion
which has been introduced into their substance. With this view they are dipped in a
tub of clear water during five or six minutes, and then spread and worked upon the
board. They are increased by this means in length, in the proportion of 5 to 3. No
hard points must be left in them. The whiteness is also better bronght oat by thia
LEATHER 681
operaUoB, irhicli is perfonned apon the flesh side. The softening tool Ss 4h Iron plate,
aboat one foot broad, rounded over aboTe, mounted upon an upright beam, 30 inches
high, which is fixed to the end of a strong horisontal plank, 3^ feet long, and 1 broad.
This plank is heayily loaded, to make it immovable upon the floor. Sometimes the
skins are next spread over an undressed clean skin upon the horse, and worked -well
with the two-hundled knife, for the purpose of removing the first and second epidermis,
called the^eur and arriire^ettr by the French megUtins, They are then dried while
stretched by hooks and strings. When dry they are worked on the stretching-iron, or
they are occasionally polish^ with pumice stone. A delicate yellow tint is given by
a composition made of two parts of whitening and one of ochre, applied in a moistened
state, and well worked in upon the grain side. After being polished with pumice, they
are smoothed with a hot iron, as the laundresses do linen, whereby they acquire a
degree of lustre, and are ready to be delivered to the glover.
For housings, the best sheepskins are selected, and such as are covered with the
longest and most beautiful fleece. They are steeped in water, in order to be cleaned
and softened ; after which they are thinned inside by the fleshing knife. They are
now steeped in an old bran pit for 3 or 4 days, when they are taken out and washed.
They are next subjected to the white or alum bath, the wool being carefully folded
within i about 18 pounds of alum being used for 100 skins. The paste is made as for
the fleeced skins, but it is merely spread upon their flesh side, and left upon them for
18 hours, so as to stiffen. They are then hung up to dry. They are next moistened
by sprinkling cold water upon them, folded up, piled in a heap, and covered with
boards weighted with heavy stones ; in which state they remain for two days. They
are next opened with a round iron upon the horse, and subjected to the stretching
iron, being worked broadwise. They are dried with the fleece outermost, in the sun
if possible, and are finished upon the stretchtr.
Calf and Iamb skins with their hair and wool are worked nearly in the same manner ;
cnly the thicker the skin, the stronger the alum bath ought to be. One pound of alum
and one of salt are required for a single ealf skin. It is left four days in this bath, after
which it is worked upon the streteher, then fulled. When half dry, the skins aro opened
upon the horse. In eight days of ordinary weather, they may be completely dressed.
Lamb skins are sometimes steeped during eight days in a bath prepared with unbolted
rye flonr and cold water, in which they are daily moved about two or three times.
They are then dried, stretched upon the iron, and switched upon the fleecy side.
Chamois, or Shamoy kather^ — The skins are first washed, limed, fleeced, and branned
as above described. They are next efflowered, that is, deprived of their epidermis by
a concave kuife, blunt in its middle part, upon the convex horse^beam. The cutting
part serves to remove all excrescences, and to equalise the thickness, while the bltmt
part softens and smooths. The skins of goats, does, and chamois are always treated
in this way. They are next subjected to the fermenting bran steep for one or two days,
in ordinary weather ; but in hot weather for a much shorter time, sometimes only
moving them in the sour bran liquor for a few minutes. They are lastly wrung at
the peg, and subjected to the fulling mill.
When the skins have been sufiBciently swelled and suppled by the branning, they may
receive the first oil as follows : a doeen skins being stretched upon the table, the fingers
are dipped in the oil, and shaken OTer the skins in different places, so as to impart
enough of it to imbue the whole surface slightly, by friction with the palms of fhe
hands. It is to the outside or grain that the oil is applied. The skins aro folded four
together, so as to form balls of the siae of a hog*s bbidder, and thrown into the trough
of the fulling mill) to the number of twelve dozen at once. Here they remain exposed
to the beater for two, three, or four hours, according to their nature and the state of
the weather. They are taken out, aired, oiled, and again fulled. The airing and fid-
ling aro repeated several times, with more or less frequent oilings. Any cheap animal
oil is employed.
After these operations, the skins requiro to be subjected to a fermenting process, to
dilate their pores, and to facilitate their combination with the oil. This is performed
in a chamber only 6 feet high, and 10 or 12 feet square. Poles aro suspended hori-
xontally a few inches from the ceiling, with hooks fixed in them to which the skins are
attached. A somewhat elevated temperature is maintained, and by a stove if need be.
This operation requires great skill and experience.
The remainder of the epidermis is next removed by a blunt concave knife and the
horse ; whereby the surface is not cut, but rather foroibly scraped.
The skins are now scoured to carry off the redundant oil ; which is effected by a
potash lye, at 2^ Baume, heated no hotter than the hand can bear. In this they are
stirred briskly, steeped for an hour, and lastly wrung at the peg. The soapy liquor thus
expelled is used for inferior purposes. The clean skins after being dried are finished
first on the stretcher- iron, and then on the horse or stretching fhtme.
682 LEATHER.
Leather ^Hungary. —This is mannfiictared by impregnating strong hides witli alanii
common salt, and suet ; by a rapid process which is usually completed in the space of
two months. The workshop is divided into two parts ; 1. A shed on the side of a
stream, furnished with wooden horses, fleshing knives, and other small tools. In one
comer is a furnace with a boiler for dissolving the alum, a vat for immersing the hides
in the solution, and several subsidiary tubs. S. A chamber, 6 feet high, by 1 5 feet
square, capable of be'ng made very tight, for preserving the heat. In one comer is a
copper boiler, of sufficient size to contain 170 pounds of tallow. In the middle of the
stove is a square stone slab, upon which an iron grate is placed about a yard sqaareu
This is covered with charcoaL At each side of the stove are larse tables, which occupy
its whole length, and on which the leather is spread to receive the grease. The upper
part below the ceiling is filled with poles for hanging the leather upon to be heated.
The door is made to shut perfectly close.
The first operations are analogous to those of tanning and tawing ; the skins being
washed, cut in halves, shaved, and steeped for 24 hours in the river. They are
then cleaned with 5 or 6 pounds of alum, and 3^ pounds of salt, for a piece of bide
which weighs from 70 to 80 pounds. The common salt softens the efiPect of the alum,
attracts the moisture of the air, and preserves the suppleness of the skin. When the
alum and salt are dissolved, hot water is poured upon the hides placed in a vat, and they
are trampled upon by a workman walking repeatedly from one end of the vat to the
other. They are then transferred into a simiUr vat containing some hot water, and
similarly trampled upon. They are next steeped for eight days in alum water. The
same round of operations is repeated a second time.
The skins are now dried either in the air, or a stove room ; but before being quite
dry, they are doubled together, well stretched to take out the wrinkles, and piled up.
When dry, they are agam trampled to open the pores as well as to render the skin
pliant, after which they are whitened by exposure to the sun.
Tallow of inferior quality is employed for greasing the leather. With this view the
hides are hung upon the poles in the close stove room, then laid upon the table, and
besmeared with the tallow melted till it begins to crackle. This piece is laid on another
table, is there covered with a second, similarly greased, and so forth. Three pounds
of fat are commonly employed for one piece of leather.
When the thirty strips, or fifteen hides passed through the grease in one operation
are completed, two workmen take the first piece in their hands, and stretch it over the
burning charcoal on the grate for a minute, with the fiesh side to the fire. The rest
are passed over the fiame in like manner. After flaming^ the pieces are successively
laid on an inclined table exposed to the fire, where they are covered with a cloth.
They are finally hung upon poles in the air to dry ; and if the weather be warm, they
are suspended only during the night, so as to favour the hardening of the grease.
Instead of the alum bath, M. Curaudau has employed with advantage a steep of dilute
sulphuric acid.
liussia leather, — The Russians have long been possessed of a method of making a
peculiar leather, called by them jwten, dyed red with the aromatic saunders wood.
This article has been much sought after, on account of not being subject to mould in
damp situations, being proof against insects, and even repelling them from the vicinity
of its odour. The skins are freed fh>m the hair or fieece, by steeping in an ash*Iye too
weak to act upon the aninyd fibres. They are then rinsed, fulled for a longer or shorter
time according to their nature, and fermented in a proper steep, after having beiai
washed in hot water. They are taken out at the end of a week, but they may
be steeped a second time if deemed necessary, to open their pores. They are now
cleaned by working them at the horse on both the flesh and gnin sides.
A paste is next composed, for 200 skins, of 38 pounds of rye flour, which is set to
ferment with leaven. This dough is worked up with a sufficient quantity of water to
form a bath for the skins, in which they are soaked for 48 hours ; they are then tians*
ferred into small tubs, where they remain during fifteen days, after which they are
washed at the river. These operations serve to prepare the skins for absorbing the
astringent juices with uniformity. A decoction of willow bark (5a/urcmerea and Salix
caprea) being made, the skins are immersed in the boiler whenever the temperature of
the liquor is sufficiently lowered not to injure the animal fibres, and handled and
pressed for half an hour. This manipulation is repeated twice daily during the
period of a week. The tanning infusion is then renewed, and applied to the same
skins for another week ; after which, being exposed to the air to dry, they are ready
for being dyed, and then curried with the empyreumatic oil of the bark of the birch
tree. To this substance the Russia leather owes its peculiarities. Many modes have
been prescribed for preparing it ; but the following is the one practised in Russia,
The whitish membranous epidermis of the birch, stripped of all woody parts, is in-
troduced into an iron boiler, which, when stuflfed full, is covered tight with a vaulted
LEATHER. 683
irom ltd, having a pipe rising from its centre. A second boiler into wfich this pipe
passes withoat reaching its bottom, is set over the first, and is lated to it at the edges,
after the two are bolted together. They are then inverted, so that the upper one con-
tains the birch bark. The under half of this apparatus is sunk in the earth, the surface
of the upper boiler is coated over with a clay lute, then surrounded with a fire of wood*
and exposed to a red heat, till the distillation be completed. This operation, though
rude in appearance, and wasteful of wood, answers its purpose perfectly well. The iron
cylinder apparatus used in Britain for distilling wood vinegar would, however, be
much more convenient and productive. "When the above bodies are unluted, there is
found in the upper one a very light powder of charcoal, and in the under one, which
served as a receiver, there is an oily, brown, empjreumatic fluid, of a very strong
smell, which is mixed with the tar, and which floats over a small quantity of crude
Tinegar. The former matter is the oil employed to impregnate the skins, by working
it iuto the flesh side with the currier's tools. It is difficult to make this oil penetrate
with uniformity ; and the Russians do not always succeed in this process, for they
turn out many skins in a spotted state. This oil is at present obtained in France by
distilling the birch bark in copper stills, and condensing the products by means of a
pipe plunged in cold water. About 60 per cent of the weight of the bark is extracted.
The skins imbibe this oil most equally before they are fully dry. Care must be
taken not to apply too much of it, for fear of its passing through and staining the
grain side of the leather. Chevreul has investigated the chemical nature of this odo*
rifcrous substance, and finding it to be a peculiar compound, has called it betutine.
In the Franklin Institute for February, 1843> Mr. Gideon I^e has published some
judicious observations on the process of tanning. He believes that much of the
original gelatine of the hides is never combined with the tannin, but is wasted ; for
he thinks that 100 lbs. of perfectly dry hide, when cleaned from extraneous matter,
should, on chemical principles, afford at least 180 lbs. of leather. The usual
preparation of the hide for tanning he believes to be a wasteful process. In the
liming and bating, or the unhairing and the cleansing, the general plan is first to steep
the hides in milk of lime for one, two, or three weeks, according to the weather and
texture of the skin, until the hair and epidermis be so loosened as to be readily re-
moved by rubbing down, by means of a knife, upon a beam or block. Another mode
is to suspend the hides in a close chamber, heated slightly by a smouldering fire, till
the epidermis gets loosened by incipient putrefaction. A third process, called sweat-
ing, used in German j, consists in laying the hides in a pack or pile, covered with tan,
to promote fermentative heat, and to loosen the epidermis and hairs. These plans,
especially the two latter, are apt to injure the quality of the hides.
The bate consists in steeping the haired hides in a solution of pigeon's dung, con-
taining, Mr. Lee says, muriate of ammonia, muriate of soda, &c. ; but most probably
phosphates of ammonia and lime, with urate of ammonia, and very fermentable animal
matter. Tbe dry hides are often subjected first of all to the operation of the fulling-
stocks, which opens the pores, but at the same time prepares them for the action of the
liming and bate ; as also for the introduction of the tanning matter. When the
fulling is too violent, the leather is apt to be too limber and thin. Mr. Lee conceives
that the liming is injurious, by carrying off more or less of the gelatine and albumen
of the skin. High-limed leather is loose, weighs light, and wears out quickly. The
subsequent fermentation in the bating aggravates that evil. Another process has
therefore been adopted in New York, Mame, New Hampshire, and some parts of
Philadelphia, called, but incorrectly, cool sweating, which consists in suspending the
hides in a subterranean vault, in a temperature of 50^ Fahr., kept perfectly damp, by
the trickling of cold spring water from points in the roof. The hides being first
soaked, are suspended in this vault from 6 to 12 days, when the hair is well loosened,
by the mere softening effect of moisture, without fermentation. — H. M.
LEATHER, MOROCCO. {Maroquin, Fr.; Saffian, Germ.) Morocco leather of
the finer quality is made from goat-skins tanned with sumach ; uiferior morocco
leather (roan) from sheep skins. The goat skins as imported are covered with hair ;
to remove which they are soaked in water for a certain time, and they are then sub-
jected to the operation called breaking, which consists in scraping them clean and
smooth on the flesh side, and they are next steeped in lime pits (milk of lime) for
several days, during which period they are drawn out, with a hook, from time to time,
laid on the side of the pit to drain, and replunged alternately, adding occasionally a
little lime, whereby they are eventually deprived of their hair. When this has be*
come sufficiently loose, the skins are taken out one by one, laid on convex beams, the
work benches, which stand in an inclined position, resting on a stool at their upper
end, at a height convenient for the workman's breast, who scrapes off the hair with a
concave steel blade or knife, having a handle at each end. When unbaired, the skins
^e once more soaked in milk of lime for a few days, and then scraped on the flesh-
684 LEATHER.
ttde to rendeV it rerj eVen. For removing the lime wliicli obstmets their pores, and
would impede the tanning process, as well as to open these pores, the skins are steeped
in a warm semi-putrid alkaline liquor, made with pigeons' and hens' dang diffosed in
water. Probably some very weak acid, such as fermented bran water, would answer
as well, and not be so offensive to the workmen. (In Germany the skins are first
washed in a barrel by a revolving axle and discs.) They are again scraped, and then
sewed into bags, the grain outermost, like bladders, leaving a small orifice, into which
the neck of a funnel is inserted, and through which is poured a certain quantity of a
strong infusion of the sumach ; and they are now rendered tight round the orifices,
after being filled out with air, like a blown bladder. A parcel of these inflated skins
are thrown into a Tery large tub, containing a weaker infusion of sumach, where
they are rolled about in the midst of the liquor, to cause the infusion within to act
upon their whole surface, as well as to expose their outsides uniformly to the tan-
ning action of the bath. After a while these bladder skins are taken out of the bath,
and piled over each other upon a wooden rack, whereby they undergo such pressure
as to force the enclosed infusion to penetrate through their pores, and to bnng the
tannin of the sumach into intimate contact, and to form a chemical combination with
the skin fibres. The tanning is completed by a repetition of the process of intro-
ducing some infusion or decoction into them, blowing them up, and floatrag them
with agitation in the bath. In this way goat skins may be well tanned in the course
of one day.
The bags are next undone by removing the sewing, the tanned skins are scraped as
be 'ore on the curriers' bench, and hung up in the drying loft or shed ; they are said
now to be " in the crust" They arc again moistened and smoothed with a rubbing
tool before being subjected to the dyeing operations, in which two skins are applied
face to face to confine the dye to one of their suHaces only, for the sake of economising
the dyeing materials, which may be of several different colours. The dyed skins are
grained by being strongly rubbed with a ball of box wood, finely grooved on its
surface.
Preparatory to being dyed, each skin Is sewed together edgewise, with the grain on
the outside, and it is then mordanted either with a solution of tin, or with alum water.
The colour is given by cochineal, of which from 10 to 1 2 ounces are required for a dozes
of skins. The cochineal being boiled in water along with a little tartar or alum for a
few minutes, forms a red liquor, which is filtered through a linen cloih, and put into
a clean cask. The skins are immersed in this bath, and agitated in it for about half
an hour ; they are taken out and beaten, and then subjected to a second immersion in
the cochineal bath. After being thus dyed, they are rinsed and tanned with Sicilian
sumach, at the rate of two pounds for a skin of moderate size. The process is per-
formed in a large tub made of white wood, in the liquor of which the skins are floated
like so many bladders, and moved about by manual labour during four hours. They
are then taken out, drained, and again subjected to the tanning liquor ; the whole pro-
cess requiring a space of twenty-four hours. The skins are now unstitched, rinsed,
fulled with beetles, drained, rubbed hard with a copper blade, and lastly hung up
to dry.
Some manufacturers brighten the colour by applying to the snHace of the skins, in
a damp state, a solution of carmine in ammonia with a sponge ; others apply a decoc-
tion of saffron to enliven the scarlet tint At Paris, the morocco leather is tanned by
agitation with a decoction of sumach in large casks made to revolve upon a horizontal
axis, like a barrel chum. White galls are sometimes substituted for sumach ; a pound
being used for a skin. The skins must be finally cleaned with the utmost care.
The black dye is given by applying with the brush a solution of red acetate of iron to
the grain side. Blue is communicated by the common cold indigo vat ; violet, with a
light blue followed by cochineal red ; green, by Saxon blue followed by a yellow dye,
usually made with the chopped roots of the barberry. This plant serves also for
yellows. To dye olive, the dtins are first passed through a weak solution of green
vitriol, and then through the decoction of barberry root containing a little ^xon
blue. Puce colour is communicated by logwood with a little alum ; which may be
modified by the addition of a little Brazil wood. In all these cases, whenever the
skins are dyed, they should be rinsed, wrung, or rather drained, stretched upon a
table, then besmeared on the grain side with a film of linseed oil applied by means of
a sponge, in order to promote their glossiness when curried, and to prevent them
becoming homy by too rapid drying.
The last process in preparing morocco leather is the currying, which brings out the
lustre, and restores the origintd suppleness. This operation is practised in different
manners, according to the purpose the skins are to serve. For pocket-books, port-
folios, and case 'making in general, they must be thinned as much as possible upon the
flesh side, moistened slightly, then stretched upon the table, to smooth Uiem ; dried
LEATHER. 665
ftf(ftin, moistened, and lastly passed two or three times tkrougli tlie cylinder press in
different directions, to produce the crossing of the grain. The skins intended for the
shoemaker, the saddler, the hookhinder, &c., require more pliancy, and must he dif-
ferently curried. After being thinned, they are glazed with a polisher while still
moist, and a g^iu is formed upon the flesh side with the roughened lead plate or
grainer of the curriers, called in French pommeUe ; they are glazed anew to remove
the roughness produced hy the pommel, and finally grained on the flesh side with a
surface of cork applied under a pommel of white wood.
Tawing of Skins. (Megisterie, Fr. ; Weitsgerberei, Germ.) The kid, sheep, and
lamb skins, are cleaned as has been already described. In some factories they
receive the tanning power of the submuriate of alumina (from a solution of alum and
common salt) in a large barrel-churn apparatus, in which they are subjected to violent
agitation, and thereby take the aluming in the course of a few minutes. In other cases,
where the yolks of eggs an added to the above solution, the mixture, with the skins,
is put into a large tub, and the whole trampled strongly by the naked feet of the
operator, till the emulsion of the e^f^ be forced into the pores of the skin. The tawed
skins, when dry, are '* staked," that is stretched, scraped, and smoothed by friction
against the blunt edge of a semi* circular knife, fixed to the top of a short beam of wood
set upright. The workman holding the extremities of the skin with both hands, pulls
it in all directions forcibly, but skilfully, against the smoothing ** stake."
In an entertaining article on tanning in the 11th vol of the Penny Magazine, at
page 215, the following description is given of one of the great tawing establishments
of London.
** In the production of * imitation ' kid leather, the skin of lamhs is employed ; and
for this purpose lamb-skins are imported from the shores of the Mediterranean.
They are imported witii the wool yet on them ; and as this wool is valuable, the leather
manufacturer removes this before the operations on the pelt commence. The wool is
of a quality that would he greatly injured by the contact of lime, and therefore a kind
of natural fermentation is brought ahont as a means of loosening the wool from the
pelt" The following is a description of one of the huildings. ** On the ground floor,
a flight of stone steps leads down to a ran^e of subterranean ^liults or close rooms,
into which the lamb-skins are introduced m a wet state, after having been steeped
in water, * broken ' on the flesh side, and drained. The temperature of these rooms
is nearly the same all the year round, a result obtained by having them excluded aa
much as possible from the variations of the external atmosphere ; and the result is*
that the skins imdergo a kind of putrefactive or fermenting process, by which the
wool hecomes loosened from the pelt During this chemical change ammonia is
evolved in great abundance ; the odour is strong and disagreeable ; a lighted candle,
if introduced, would be instantly extinguished, and iiy'urious effects would be per-
ceived by a person remaining long in one of the rooms. Each room is about ten
feet square, and is provided with nails and bars whereon to hang the lamb-skins.
The doors from all the rooms open into one common passage or vault, and are kept
close, except when the skins are inspected. - It is a point of much nicety to determine
when the fermentation has proceeded to such an extent as to loosen the wool froxa the
pelt ; for if it be allowed to proceed heyond that stage, the pelt itself would become
injured.
When the fermentation is completed, generally in ahout ^'ve days, the skins are re^
moved to a beam, and there " slimed," that is, scraped on the flesh side, to remove a
slimy substance which exudes from the pores. The wool is then taken off, cleaned,
and sold to the hatters, for making the bodies of common hats. The stripped pelts
are steeped in lime-water for about a week, to kill the grease ; and are next '* fleshed
on the beam." After heing placed in a " drench," or a solution of sour bran for
some days to remove the lime and open the pores, the skins are alumed, and sub-
jected to nearly the same processes as the true kid-skins. These Mediterranean lamb'*
skins do not in general measure more than about 20 inches by 12 ; and each one fur-
nishes leather for two pairs of small gloves. These kinds of leather generally leave
the leather-dresser in a white state ; hut undergo a process of dyeing, sonening,
** stroking," &c., before being cut up into gloves.
The tanning of one average-sized skin requires ahoot 1^ lbs. of good Sicilian
sumach ; but for leather which is to receive a hright scarlet dye, from one half to
three quarters of a pound of gall-nuts are employed in preference. Inferior goat skins
are tanned with a willow bark infusion, in pits, in which they are turned repeatedly,
and laid out to drain, as in tanning sole leather. The finest skins for the brightest
aearlet are cured with salt, to prevent their receiving damage in the transport, and
are dyed hefore being tanned. This method is practised in Germany and France.
Leather of deer and sheep- skins is prepared with oil, for the purpose of making
breeches, &c.» and for wash-leather, used in cleaning plate. AAer they are completely
686 LEATHER, CURRYING OF.
washed, limed, and beamed, as above described, they have their ''grains-surface re-
moved, to give them greater softness and pliability. This removal of the grain is
called " fVizing,** and it is done either with the round edge of a biont knife, or with
pumice-stone. After being treed from the lime by steeping in fermented bran-water,
they are pressed as dry as may be, and are then impregnated with cod-oil, by beating
with stocks in the trough of a kind of fulling mill. Previously to the application of
the oil, they are usually beat for some time alone to open their substance. The oiled
skins are stretched, hung up for some time in the air, then fulled with oil as before — a
process which is 8 or 9 times repeated. The oil is slowly and evenly poured upon the
skins in the trough during the action of the beaters. One hundred skins usually take
up in this way from two to three gallons of oiL The fulled oil skins are thrown into
large tubs, and left for some time to ferment, and thereby to combine more inthnately
with the oil. They are lastly subjected to a weak potash lye bath, to strip them of the
loosely adhering oiL They are then hung up in the air to dry, and dressed for the
market — H. M.
LEATHER, RUSSIAN, aa tanned at Kazan, The hides to be tanned may be
either fVesh from the animal or dry, no matter which ; they are first laid to soak for
3 days and nights in a solution of potash, to which some quicklime is added. The
potash used is made of the tree called in Russ Him (the common elm), which sort is
said to be preferable to any other, if not essential ; it is not purified, so that it is of a
brown colour and of an earthy appearance : about 12 poods of this (the pood is 36 lbs.
English), and 2 poods of lime, serve for 100 skins. As they have no way of ascer-
taining the degree of causticity of the alkali but by its effect upon the tongue, when
they find it weak they let the skins lie longer in the solution.
When the skins are taken out of this solution they are carried to the river, and left
under water for a day and a night.
Next a vedro of dog's dung is boiled in as much water as is enough to soak 50 aking,
(the vedro is equal to 2*696 English imperial gallons) but in the winter time, when
the dung is fh>zen, twice that quantity is found necessary. The skins are put into this
solution, not while it is boiliog hot, but when at the heat which the hand can bear; in
this they lie one day and one night
The skiuB are then sewed up so as to leave no hole; in short, so as to be water-tight;
about one third of what the skin will contain is then filled up with the leaves and small
twigs chopped together of the plant called in Russ Toloknanka {Arbutus ma-ursi,
sometimes called bear berry), which is brought from the environs of Solikamskaga,
and the skin is then filled up with water.
The skins thus filled are laid one on the other in a large trough, and heavy stones
upon them, so as by their weight to press the infusion through the pores of the skin in
about 4 hours *, yet, as it was said at the same time, that the skins are filled up with
the same water which had been pressed out 10 times successively, and that the whole
operation takes but one day and one night, this leaves but 2^ hours for each time.
The skins are then taken to the river and washed, and are ready for the dyeing.
The whitest skins are laid aside for the red and yellow leather.
(The operations in dyeing follow, but are here omitted.)
To soften the skins after dyeing, they are har.vsed by a knife, the point of which is
curved upwards. — H. M.
LEATHER, CURRYING OF. The currier's shop has no resemblance to the
premises of the tanner, the tools and manipulations being quite different
Within the last twenty or thirty years, many tanners have added the currying
business to their establishments, and many curriers have likewise commenced tanning;
but in each case, an extension of premises is necessary, and the two departments are
still separate. The advantages derivable firom this arrangement are two-fold, — first,
a saving of time is effected, for as the tanned leather is sold by weight, it is required
to be well dried before being disposed of to the currier, an operation which is not
needed where the tanner carries on the currying also ; and secondly, by the currier's
art, the skins can be reduced to a comparatively uniform thickness previous to their
being tanned, thus saving time and bark (used for tanning), and insuring a more
equal distribution of tannin through the substance of the skin. In the following
description, the business of currying will be considered as practised at the present
time.
The currier*s shop or premises, to be convenient, should be spacious. A frequent,
though not universal method, is to have the ground-floor appropriated to such ope-
rations as require the use of a large quantity of water. The place or apartment thus
used, is called the scouring-house^ and is commonly furnished with a number of tia<s
or casks open at one end, in which the leather is placed for the purpose of soaking,
and undergoing such treatment as will be hereafter described. In this apartment also
is placed a large, fiat, slate stone, called a scmtrin^-sUme, or» more consistently, tha
LEATHER, CURRYING OF.
687
1112
Stone on which the leather is sconred. This stone, which has its face perfectly flat
and smooth, and which should measure 8 or 9 feet in length, by 4^ broad, forms
a table, supported generally by masonry, but sometimes by a strong frame of wood,
so constructed, that the water, which is freely used in scouring, may drain off on
the opposite side from that on which the workman is engaged ; an inclination of
about three or four inches on the width of the table, is suufficient for this purpose.
Another piece of furniture very frequently found ta, or on the same floor with the
scouring-house, is a block of sandstone, in the form of a parallelopipedon, between
S and 3 feet long, and 9 or 10 inches broad, the upper face of which is kept as
near as possible a perfect plane ; this stone is fixed at a convenient height on a
strong trussel, and is called the ntb'Stoue, because here the workman rube or sharpens
his knives and other tools. In some large establishments where the premises and
water are heated by steam, the scouring-house will be found with a service of pipe
leading to the various vats, and the boiler, for generating the steam, may be con-
vententlv placed in or near this part of the building.
The floor above the scouring-house, in the arrangement here laid down, is what ia
specially designated the shop. The furniture in this department consists of a beamf
{JUf. 1 1 12) on which the leather is shaved. It con-
sists of a heavy block of wood, on which the
workman stands, and into one end of which a stiff
piece of wood is firmly mortised, at an angle of
about 85^; this upright (so called) is about a foot
wide, the height being greater or less, according to
the height of the workman, each of whom has his
beam adjusted to meet his convenience. On the
front of the upriaht, a piece of deal is firmly
screwed, to which is glued a face or plate of lignum
vitcB., worked to perfect smoothness to agree with
the edge of the knife used in the operation of
shaving. It is of the greatest importance to the
workman, to keep his skin from injury, that his
knife and beam should be kept in good order. A
table or taUes^ generally of mahogany, large planks
of which are i:^ed for the purpose to avoid joints, may be said to form a necessary
part of the furniture of this department These tables are firmly fixed, to resist the
pressure of the workman when using various tools ; and as light is of the greatest
consequence in the operations performed on them, they are usually placed so as to
have windows in front of them. A- high trussel is frequently used, across which the
leather is thrown, after undergoing any of the processes, while the currier subjects
other pieces to the same operation.
Another part of the premises is termed the drying loft. In good buildings the
drying loft is surrounded with weatlier-boards, constructed to be opened or closed as
may be required. The use of this part being the drying of the leather, the ceiling is
furnished with a number of rails or long pieces of wood, with hooks or nails on
which to hang the leather for drying, and where steam is used for this purpose, the
floor is traversed with pipes for heating the loft. Here also is a table, similar to that
previously described ; it should not he less than 7 or 8 feet long by 4} broad, if
possible, without joint, and with a smooth face.
There are other subordinate departments, each ftimished with a table similar to
those described.
Of the tools used in currying, the knife stands first in importance (fig. 1113).
Here a and b are two handles, a is held in the 1113
left hand, and forms a powerful lever when the
edge c is applied to the leather. The blade of
the carrier's knife is peculiarly tempered; it is
composed of a plate of fine steel, strongly
riveted between two plates of iron. This in-
strument is taken to the rub stone, and ground to a perfectly sharp edge by successively
rubbing forward and backward ; care being taken to keep Uie edge true, that is,
straighL "When this has been satisfactorily accomplished, it is still further rubbed on
a fine Scotch or Welsh stone called a clearing-stone, until tbe scratches of the rub^
stone disappear.
In this operation a fine thread or wire forms on the edges, for the knife has two
edges (cc) which must be carefully got rid of; after which it is wiped dry, and the
edges greased with tallow or oil. The workman then takes a strong steel, and placing
himself on his knees, he fixes the knife with the straight handle b against any firm
body, and the cross handle a between his knees ; then holding the steel in both hands
LEATHER, CURRYING OP.
peodicular ; hj thil mcui the edge is tamed completelr otct. If the knife t
well tempered, the edge tbni obtamed Till be irregiilw, or brokeo; in either of irhieh
CMea it if of DO nu vhateirer.
To keep tbe imlrnment jntt Jeicribed in proper order r«qiiir<s grtia •kill on tbe
put of tbe currier. Tbe edge ij so delicate ind liable to iajurj that it cannot be osed
.... more than iminnle ortwo vithoat loung iu keenneu. To r««tore tfaii a vny
earefullj' prepared amall iteel is nsed.^. II 14; the point of the Media fint mn
along the grore which is formed b/ turning the edge orer. md th« sieel ii
then made topasa oattide the edgeO^?- 1310). Il is remai^Ue (bat a skiLfal
I hand can tbni restore the efficieocjoftheknife, and keep itin workfor boor*
without going fbr a new edge to the rub^loM, Tbe otoer tool* will be de-
•eribed ai their ues are meotioned.
Tbe flnt thing done b; (be carrier is tbe aoaking of the leather received
IVom the tanner in water; the skin requires b thoraagh wetting, bnt not to
ation. In some cases the thicker parts are partiall? soaked before tbe immenka
of the whole, and vhen from the nalore of the skin thii cannot be done, water ii i^
plied to the stoat parts after the dipping ; it is reqaislte tbat tbe whole should be aa
near as poEsible equally weL In some instances the wetted leather is bealen, and
somecimes a cnarge gralain^- board (hcTcafter to be deicriljed) is ascd.ljjmake it mot*
SDpple previous to sbaviagit. The skin is then laid over (be bcam(/^. IllG) and the
rough ni;shy portion is ihaved off. This opemtion is gcnerallj ciUled aiiviiig. In
all ihe operatioDS at the learn the leather i> kept in iu place hj preuure of the knees
or bodT of the workman from behind. In lAiving the right hand handle of the knife
somewhat precedes (he left, but in ihavin^, properl; so called, tbe left hand prrcedra
the right, ^. 1117. lu tkiiiing the knife is driven obi iqu el; a few inehes at • time, is
■having it ii driven with great force, not unfrequendj from the top to the bottom of
the beam ; great skill is requisite in the performance of these opervtions, to guide tbe
knife and to keep its edge. The cnrpeuter'i plane can be most completely rrgnlated
b; (be projection of tbe plane iron from the wood, bnt tbe currii-r's knife admits of
DO such arrangement, and the nnskilful cnrrier it constantlj liable to iqjure tbe
teaiherbj catting (hrough it, as well as b; failing to produce a regnlarnbstaaoe. Tbtt
LEATHER, CURRYING OF. 689
kind of akin, and the nae for which it is designed -will regolate the work at the heam.
In some cases, as in the calf-skin, it is skived and then shaved, or, (as it is oalled)^al-
tened at right angles to the skiving — in other kinds, as the cow-hide prepared for the
npper leather of heavy shoes, after skiving it is thaoed acroM (i. e, nearly at right angles
to the sklvingX and^a/tenerfhy being again shaved in the same direction as the skiv-
ing. In some mano^wtories Uiere are certain kinds of leather which are subjected
to the operation called by carriers aUmtng^ before flattening : this is done by forcibly
driving the stock'tttme (fig. 11 18) over the grain side of the leather, thereby stretching
it, and rendering the grain smooth. The flattening process is considerably facilitated
by this stoning, and if the skin has been allowed slightly to harden by exposure to
air, and the edge of the knife is fine, as it should be, the workman has but to strike
the flat part of the knife over the leather after the shaving is performed, to produce a
beautiftd &oe to the flesh side of the skin* It will not be difficult to understand that
1118 1119
■ ~r tz:
a good hand is easily distinguished fh>m an inferior one in this part of the bnsinesa.
With such nicety will a skilful workman set the edge of his knife, that although there
seems nothing to guide him, he can take riiaving after shaving from the hide extending
from the top to the bottom of the beam, tiius rendering the leather extremely even in
its substance.
After the process of shaving is completed, the leather is placed in water, where it
remains until it is convenient to can^ on the operation next required. It is to be
observed that in the condition in which leather is shaved, it cannot long be kept
without becoming heated ; when, however, it is put into water, it is Mife from injary,
and may be kept a very long time, provided the water be occasionally changed
for a fresh, sweet supply ; stale water is regarded as ixgurious for the skin to
remain in.
Scouring is next proceeded with ; the skin is taken out of the water, and laid on
the sconring-stone. In respectable manufactories, it is usual first to scour on the flesh ;
this is done by passing a sUcker smartly over the flesh side, by which the grain of the
leather is brought into close contact with the sconring-stone, and, being in a wet
condition, the air is easily excluded, so that the l^ither atichs to the stone. A plen-
tiful supply of water is now applied, and a large brush, with stiff hairs, is rubbed
oTer the flesh, or upper side. Portions of the siuface, in a pulpy condition, come off
with the scrubbing, and the skin presents a soft, whitened, pulpy appearance ; the pores
are rendered capable of containing more moisture, and, altogether, the leather is much
benefited. The s/icAcr ii a plate of iron or steel, or for particular purposes, of brass
or copper ; it is about five inches long, and like the stoch-stone^ is fixed in a stock, or
handle {fig, 1119). It is sharpened at the rub-stone^ by grinding the plate perpendicu-
larly, and then on either side, thus produdng two e^es (or rather, right angles).
The edges thus produced are not of an order to cut the leather, but rather to scrape
it The sUcher is not intended to remove irregularities in the leather, but its uses
are various^ and it may be considered a very important tool as will hereafter
appear.
In the process of tanning^ the grain side of the hide or skin becomes covered with
» whitish body, derived fh>m the bark called Uoomf this is more or less difficult to
remove accordbig to the hardness or softness of the water used in tanning, and the
peculiar treatment of the tanner. It is, however, the currier's business to remove it,
which be effects thus : — In the case of leather, whose grain is tender, as cordovan^
which is manntactured fWim horse hides, the grain being kept uppermost, the leather
is spread on the scooring-stoue, and being plentifully supplied with water, is stretched
by using the slicker, or a fine pebble, ground to Uie shape of the stock-stone, the
bloom is thus loosened, and, at the same time, by making it adhere to the scouring-
stone, the next operation is readily carried on, which consists in smartly brushing
the grain with a stiff-haired brush, at the same time keeping a quantity of water on
the surfiice, the slicker is again used to remove the water and loosened Moom, and
the scourinj^ is complete. In the scouring of calf-skins, and cow or ox hides, the
^tock-stone is used to fix the leather, and a pieoe of pumice-stone, the face of which
has been ground to smoothness, and afterwards cut in grooves, is Uien forcibly rubbed
over the grain, in order to remove the bloom. In this, as in other operations, on the
soottring-stone, water is a necessary ingredient The Mxm being sufficiently loosened
by the pumice-stone, the brush is used to scrub up the remaining dirt, which is then
Vol. II. Y Y
090 LEATHER, CURRYING OF.
removed by the ttock-stone or slicker. In harness leather, 'which is stont, and reqvitca
to be stretched as much as possible, the pmntce-stone is seldom used, the stock-stone
and scooring-brush being lustily appli^ until the bloom is sufficiently removed.
Ordinary mannfiictnrers within the present (nineteenth) oentniy, have ooosidered
the operations of the scouring-koiue complete at this point The modem currier
takes a diffierent view, and not onfreouently detains his ^couretf pn^rty for days, and
sometimes for weeks in the acouring'iunue.
If the leather is imperfectly tanned, or it is required to be made of a bright colour,
there are other processes to be passed through. In these cases sumach (an evergre«k
shrub of the natural order Anacar^Uaeea^ genus Khus^ and from the bark of which all
the leather made in Turkey is said to be tanned) is infused in boiling water, and
when cooled to a tepid state the leather is placed in it After staying a sufficient
time it is taken to the scouring-stone ; if cordovcm^ it is slicked as dry as can be well
accomplished on the flesh side; other leather is for the most part slicked in a
similar way on the grain side. Saddle leather which is required to be of a bright
colour is still farther placed in warm water slightly acidulated with snlphuric or
oxalic acid, or both ; here for a time it is kept in motion, then taken to the soouriog-
stone, it iswsshedwith peculiar chemical lotions, according to the taste or knowledge
of the workman ; then again it is dipped in tepid sumach infusion; then slicked with
a copper or brass slicker (iron is liable to stain leather thus prepared), and a diin
coat of oil being applied to either side it is removed to the drybtg-hJL Until within
a very few years, much time and trouble were taken to produce very bright leather for
the saddler ; but of late, brown-coloured leather hss been adopted to a considerable
extent, as it is less Uable to become soiled. Nearly all leather is placed a abort time
in the hfl before fiirther manipulations are carried on, in order to harden it dighlly
by drying.
In the drying-loft, or its immediate vicinity, the leather receives the dmUim§
(dattbing, probably) or stuffing. The substance so called is composed of tallow
brought to a soft plastic condition by being melted and mixed with cod-lwer oil;
occasionally sod (an oil made in preparing sheep skins) is in very small quantities
added to the mixture. This is laid upon the leather either with a soft haired brush
or a mop made generally of rags.
The leather is prepared for stuffing by wetting slightly such parts as have become
too dry. It is then taken to the table previously described, which being slightly
oiled the process is carried on by placing the skin on the table in the manner most
convenient for stretching it and making the surface smooth. In those kinds that
hare a rough wrinkled grain the flesh side is placed next the table and the siock-MtBme
is used very smartly to stretch and smooth the grain. A kind of damp or hoUfiut,
composed of two cheeks fastened with a screw, is sometimes used to prevent the
leather from moving during this operation, but in general these are not required ;
the slicker is then applied to remove the marks left by the stock-stone, and a thin
stuffing being spread over the pain it is turned over, slicked on the flesh lightly, a
coat of stiffing is spread over it, and it is hung up to dry. In those kinds which
have to be blacked (or stained) on the grain, a little cocf oil onl^ is spread om the
grain, and the slicker is applied on the floh side most laboriously previous to
stuffing. Much skill is required to give the requisite quantity of stuff (dubbing) to
the leather without excess, excess being iigurious, and the quantity required is
farther regulated by the freshness or otherwise of the leather, the tan-yard from
which it comes, and the treatment it has received in the sconring-house.
When dry, the skins or hides are folded together, to remain until required. It is
certain the leather improves by remaining some weeks in this condition. It should
be observed that, in drying, the leather absorbs a large quantity of die olnginoos
matter with which it is charged, and the onabsorbed portion forms a ^ck coating of
hardened greasy matter on &e flesh side.
Leather which has to be blackened on the flesh (imut leather')^ from this point
receives different treatment from grain leather. Wax leather is taken to the Atp-
table and softened with a graining-board. The skin is laid on the table and doubled,
1121
1120
grain to grain, the ^amin^-board (Jig, 1121), which is confined to the hahd by a leather
atrap (a a), is driven forward and drawn back alternately until a grain is raised on the
LEATHER, CUBRYING OP. 691
leather, and it lias attained the required snppleneai. Observe, the graming-board is
slightly roonded on the lower sar&ce, and traversed by parallel grooves fix)m side to
side, which are coarser or finer, as occasion reqairea The grease is next removed
fVom the flesh by the slicker, and afterwards a sharp slicker is passed over the grain
to remove gJ[^&M or other accnmolations from it. The next process is called
whitening. The leather is laid over the heam, and a knife with an extremely fine
edge is used to take a thin shaving from the fiesh side; this is a point at which a
cnrrier^s skill is tested. The knife used is one that has been very much worn, the
quality of which has been tested to the utmost; and so extremely tme is the edge
expected, that not the slightest mark (scratch) is allowed to appear on the surface of
the leather. Only a good workman can satis&ctorily accomplish thia The slightest
gravel in the flesh of the skin may break the edge of the knife in pieces, and it is not
easy to rectify so serious a misfortune; besides, a poor workman may tear up the edge
by steding^ an operation which ought to mend the mischief instead of provoking it.
A fine graming-board is next used to soften the leather ; the stifier parts being
boarded both on the grain and flesh sides, and the operation being carried on in two
or three directions, to insure both softness and regularity of grain. Boarding is per-
formed l^ doubling the leather and driving the douUe part forward and drawing it
backward by the graining-board.
The leather is now prepared for the tmixer, and passes, consequently, into his
hands. Waxing, in large establishments, is a branch considered separate from the
general business, and is usually in the hands of a person who confines himself to this
occupation alona The skin is laid on a table and the cdUmr rubbed into the flesh side
with a brush. It is necessary to give the brush a kind of circular motion to insure
the required blackness in the leather. The colour is made by stirring a quantity of
the best lampblack into cod-liver oil; sometimes a little dubbing is add^ and in order
to make it work smoothly so as not to clog the brush, some stale ton water from the
vats in the scouring house is beaten up with the mixture until it combines therewith.
The preparation ik the colour is an important affair, and requires a considerable
amount of time and labour to render it such as the waxer desirea
A diek'ttone, or glass, is next used ; this tool is about the size and shape of the
slicker, but instead of being ground like it, the edges are very carefHilly removed, so
that while, from end to end, it preserves nearly a right line, it is circular across the
edge. The stone (a fine pebble) is little used now, plate-glass being substituted for it.
The use of the tool just described is to smooth the flesh after the operation by the
colouring brush, thereby getting rid of any marks made on the surface.
The next step in waxing is what is called sizing. Size is prepared by boiling glue
in water— the melted glue is diluted with water to the extent required — in some
cases it is softened by mixing cod-liver oil with it in cooling. When cold, it is beaten
np with various ingredients, according to the taste or experience of the waxer; the
waxer then well rubs the size into the coloured side of the leather, and with a sponge,
or, more generally, the fleshy part of his hand, smooths it ofL When dry, the sUck'
stone, or glass, is again applied, thus producing a polish on the size ; and a very thin
coat of oU completes the work. In different manufactories different methods are pur-
sued, but the above is convenient and satisfactory in almost all circumstances, ft is
now ready for the shoemaker.
Leather intended to be blacked on the grain, is left folded np when dr^ after stuff-
ing. Some years ago it was the custom to stain these kinds of leather, while wet in the
scouring-boose, by spreading stale urine over it and then applying a solution of copperas
(sulphate of iron). That method is now exploded. The dry skins or pieces of leather
are laid on the shop-board : a brush is used to saturate the grain with urine, or as is
now more common, a solution of soda in water, and a peculiar preparation of iron in
solution is afterwards laid over it, which blackens the surface. It may be observed
that in wax-leather a body of black is laid on, and rubbed into the flesh ; in grain
leather the black is a stain. After the blackening, it is necessary to rub a small
quantity of oil or dubbing over the blackened surface, then turning the oiled grain
toward the table, a sharp slicker. is used on the flesh side; the leather sticks to the
table by means of ihe oil, and the slicker is driven so smartly over it, that it is stretched
on the table, at the same time that the grease is -removed. It is quite an important
point to take off Ae stretch out of the leather in this operation, after which it is turned
over ; the table is covered with a very thin coat of ha^ tallow, a roll of tallow being
rubbed over the table, for the purpose of keeping the leather fastened to it. A duU
slicker is used on the grain to remove remaining marks and wrinkles, or to smooth
any coarse appearance on the grain; a sharp slicker removes all the grease, and a
thin coat of weak size, made of glue dissolved in water, is spread over it and the pro-
cess, usually called seasoning, is completed. The next object is carefully to dry the
seasoned leather, and in this state it may be stored without injury,
TT 2
692
LEATHER* CUERYING OF.
The next step U yerj similar to that deseribed in tbe case of wajr-lMiiftcr, tadcilkd
whitening : — it is then softened by means of a fine graining-board, or a board of the
■ame shape and sise covered -widi cork, the grain side is placed next the table, and
the flesh doubled against the flesh, and thus driven forwunl and backward ondl the
required degree of suppleness is obtained. The loose particles of flesh are bruibed off
and a slicker carefully passed over the grain removes all markt of the last opexatioiL
If a sufficiency ofttuff has not been appli<d in the drying-loft, the deficiency ia ranedied
by a coat of taUcnP'dubbing now spread ever the grain and allowed to remain aome boon.
As the leather absorbs the oily matter a hardened coat of grease haa to be remoTed
by the aid of the slicker. The leather is then sized, and a very thin coat of oil spread
over the sise, completes the operation.
In the preparation of various kinds of leather, or of leather for particular poipoeei,
the currier has particular appliances. Harness leather is connderably d^er thu
other kinds before stuffing, and is subjected to umnense labour by the stock-stone ud
slicker, to procure a smooth grain. It is blackened when dry like other pran leather,
but instead of the oiling and other processes described, the hardest tallow procorable
is rubbed into it, «ftmea with a fine pebble, slicked, and tallow again nibbed into it by
die hand. When dry after this operation, the grease is slicked flrom the flesh side,
and a repetition of the tallowing, stoning, and rubbing finishes the work.
Saddle leather, which is cut into comparatively small pieces, after baideniog ia the
drying loft, is passed through a very different process from any described prerioosly.
The skin of the hog is much used for certain parts of hackney saddlea, and the
bristles, when removed by the tanner, leave indentations, or even holea in the tasaed
skin. Probably it was deemed desirable to obtain some imitation for the parti of the
saddle where the hog skin was not suitable. The skin of the dog-fish (SgAiaa.
Cuv.), to some extent supplied the imitation, having hard tubercles on its lurftoe.
At first the skin was laid on the leather and lustily pressed into it by rabbisg it with
a pebble or plate of glass ; at length a press was invented, and more recently tarioDi
methods have been proposed to prodaoe the best effiect We have here C/S^. 1122) i
1122
representation of one of these presses, which may stand as a type of all others; a ^
are the feet into which the upnghts are inserted; b b are the two upright sides tied ti
the top by c, a similar cross piece ties them a little above the feet; rf is a lew
fastened with hinges, which closes upon c when the press ia not in use; e e are arrets
which press on the iron plate, in which the axes of the roller/are inserted ; these plstf*
embedded in the uprights b b have considerable play, so as to allow the rollers/*
LEATHEB, CURRYING OR
693
more or less preisare u the ease may require. The dotted line 1 1", representa an Iron
bar or cylinder, sopplied with a small cog wheel at t\ and a crank-handU j, this is
tamed roond by the hand, and the small cogwheel acts on a larger one k, which is
attached to the axis of the roller /: /is a solid roller of hard wood, such as lignum
viUt; npon this cylinder is strongly glued the fiak akin, prevxooslj alluded to ; A is a
cylindrical solid piece of wood corewd with stoat flannel ; / is a piece of leather on
whi^ the leather to be pressed is placed; when all is a^jasted the piece to be pressed
18 placed on 2, the handle is moTcd riowly round, and the whole is carried between
the rollers; the leather thus receives the imprint of the^A akin^ and at the same time
becomes extremely solid. After drying, this is fit for the saddler.
Of late years the currier has undertaken an office which was prerionsly the
business of the boot maker; namely, the blocking of boot fronts. This is performed by
the instrument represented by fy, 1 123. The leather is first dressed, as previously
1123
deseribed, up to the point of being ready for whitening. The fronts are then cut (flg,
1 123 a), and when folded or doubled appear as^. 1 123 6, V I', 1 1, is a strongfhune-
work; 2, represents a pair of cheeks, strongly fiutened in the fhune, and regulated as
to distance by a screw ; these cheeks are lined with zinc ; 3 is a strong plate of metal,
the angle at 3 corresponding exactly with the angle of the cheeks ; the ends of this
plate are fixed in movable plates passing down the columns T 1' ; 4 is a handle by
which the instrument is worked, and which by coff-wheels acting on the movable
plates brings 3 downwards. The front, a, is laid, after a Uiorough soaking in water,
T T 3
694
IXATHEE, CCEETING OF.
orer the eheeki S, &t haDdle bemg taroed, 3 oomei down npoo the frant, nd
forcet it through the imall opening between tbe cheeks, and whea brouglil cm btki*
the cheekt, it hka the app«aranee here gi*en (fig. 1133 c). The plate 3 baiiiig orrial
the front between tbe cheeks, i* remoTed (Mav), and the weight S laiKi is
bfioffiag the perpeadieuhir movahte plates to their plM£^, when 3 it agiin pm in
poaiUOD ) and thai the operation ii rspidlj carried on. Alter thii the fnUi at
regularly placed on a tlock, being forced into position bj an ioMnuueiit olltd tix
jSou»dtr (Jig. 11S4) and taditd to their place \ after thii the; an iliglitlT oiled vA
«nable« the vorkman to hold them better than he ooold oo the c<
iwe again blocked by the aaxer, and when the«e proeeue* are careftHj ?**««*•
nnnch trouble is laved to the boot-maker. Of conrce, in a mannflBaorj mMJ «"
pliancei are found which are not here mentioned ; the general idea, however, m'J "
«wily gathered from thli description. The work is dirtj and TeiJ '■'^"""^^
qniring great skill and experience, and conieqnentlj good workmen tin gC"*^'
Mmmaaded better wages than other mechanics. ^ tj
Hides intended for corering coaches are shayed a« thin a* shoe hides, sai W""
on (he grain. — H. M.
LEATHER SPLITTING. 695
LEATHER SPLITTING. Thit operuioD ii employed lometlmei upon certain
■orti of leather for gloTert. for bookbinders, ibeath-makera, and alway ■ to gire a UDiform
ihicknevi to the leather destined for the cotton and wool card-nisken.
Ffjt. 1136, 1 1ST, 1138, 11!9 represent svellcontriTed DUWhine for thMpnrpoie, of
which fig. 1136 ihows the Ihrnt view, j^. 1127 a view from the left side, J^. IISB a
ground plan, and Jig. 1 1 38 a vertical section aerosi the micbine. a is a strong tahle,
fiimithed with four legs b, which la the right ud left band bean two horliontal pieces c.
■
^
'
im
fi
rf
'(
; Ml 1! II 1 II
)'A
-fl
>-B-
, '-^ ^
■nX
1'
ii.ir-Bi
N
.
i
^1
•
Each ofthete piecei is cut oat in front, lo as to form in its (Dbstanoe a half-round fork,
that receives a cflinder i^ carrjing on its end a toothed nmr-wheel t. Blotion iacom-
DiDDicated to the wheel b; meaiu of the handl«/, upon whose axis the pinion i it fixed.
working into the wheel <A made htt to the end of the erlinder round which the leather
ia rolled. The leather it fixed at one of ita ends or edges to Ibe cylinder, either with
a wedge pretted into a groove, or b; a movable s^ment of the cylinder itself.
The table, a, is cat ont Icnglhwite with a ilot, that is widened below, ai shown in
Jig. 1138.
Theknife A(^. 113aandllS9) it filed flat nptm the labile with screw bolts, whose
heads are coontersank into the table, and secured with taps beneath (_Jig. 1 138), the edge
of the knife being placed horiiontally over the opening, and parallel with it.
lajig. llSSthe leather, h, is shown advancing against the knife, getting split, and faat
a portion coiled roond the cylinder, which is made to revolve in pcoportion as the
leather is cleft. The upper portion of the leather is rolled upon the cylinder d, while
the under half, I. falls through the oblong opening apoo the gronnd.
Id regulHting the thickness of the split leather, the two supports, m, act ; they are
madefest to the table a (oneoD each side of the knife), and are mortised into the table
by two tenons secured beneath. These snpporU are famished near their tops with
keyed slots, by meau of which the horlzoDtal iron rodo C,A?*. HS^, USB) it lecured.
696
LEATHER SPLITTING.
and ontiide of the nprigliti they press upon the springs p p, which tend to ruse the rod, o,
in its two end slots ; but the adjusting screws q, which pass down through the tope of tke
1129
^
1
I «
Itt |[tf ||«
supports into the mordse n (Jig. 1188), and press upon the apper half of the dhided
tenon, counteraDt the springs, and accordingly keep the rod o exactly at any desired
height or leveL The iron rod o carries another iron bar, r, beneath it, parallel and
also rectangular, fig, 1 1 28. This lower bar, which is rounded at its under laoe, lies upon
and presses the leather by the action of two sorows, which pass through two upright
pieces « {figs, 1 126 and 1 128) made fiist to the table ; thus the iron bar r may be miide
to press forwards the edge of the knife, and it may be a^nsted in its degree of pressure,
according to the desir^ thickness of the leaf of split leather that passes through
under it
Fig, 1 128 shows that the slant or obliquity of the knififi is directed downwards, otct
one of the edges of the oblong opening g ; the other edge of this opening is proTided
with an iron plated (^K^f. 1128, 1129), which serves to guide the blade in cutting the
leather to the proper depth. For this purpose the plate is made a4)astible by means
of the four springs u{fig, 1129) let into the table, which press it downwards. Four
screws, o, pass down through the table, each belonging to its respectiTe spring a,
and by means of these screws the plate t may be raised in any desired degree. Each
of the screws u has besides a small rectangular notch through which a screw bolt x
passes, by which the spring is made fiist to the table. Thus also the plate t mMj be
made to approach to or re^e from the knife.
y, in figs. 1126 and 1 128, is a flat board, laid upon the leather a little behind the edge
of the plate i ; this board is pressed by the cylinder z, that lies upon it, and whose
tenons rest in mortises cut out in the two supports dK. The cylinder z is held in its
position by a wedge or pin, b (figs, 1 126 and 1 127)^ which passes through tiie sopportsi
When the leather has been split, these pins are remored, and the cylinder rises Uien by
means of two counter-welghts, not shown in the figures.
The operation of the machine is as follows : — The edge or end of the leather being
secured to the cylinder d, the leather itself having the direction upon the table shown
in fig. 1 128, and the bar r its proper position over the knife, the edge begins to enter in
this position into the leather, while the cylinder d is moved by the bundle or winch, and
the piece gets split betwixt the blade and the roller d. When the other end of the
leather, A, advances to the knife, there is, consei^uently, one half of the leather split ; the
skin is to be then rolled off the cylinder d; it is turned ; the already split hal^ or the
end of the leather, k, is made fast into the wood of the cylinder, and the other half is
next split ; while the knife now acts from below, in an opposite direction to what it
did at first
That the unrolling of the leather firom the cylinder, d, may not be obstructed by the
pinion i, the stop-w<dge e (figs. 1 1 26, 1 127) is removed from the teeth. In the process
of splitting, the grain side of the leather is uppermost, and is therefore cut of an uni-
form thickness, but the under side varies in thickness with the ine<tiiality of the skin.
Several other ingenious contrivances have been introduced for this purpose, illus-
trated descriptions of which have been given by Hebert, who states that a splitting-
machine, long used by the Messrs. Bevington, of Bermondsey, had been made to split
sheepskins into three equal parts, one of which, that on the grain side, might be used
as leather; the middle portion converted into parohment ; and the slice on the flesh
side, bein^ nneoual in Uiickness, and dierefore unfit for any better use, being used for
glue makmg. In this machine the skin is drawn between two revolving rollers, snd
presented, as it emerges from their grasp, to the edge of a long and very sharp knifo,
which is kept continually moving a little backwards and forwards with great velocity.
As a skin of^uneqnal thickness could not be srasped in the proper manner between two
LEATHER, VEGETABLE. 697
perfectly true and rigid roUen, the npper roller, instead of being folid, is eompoeed
of a nomber of circular discs or rings of metal, about half an inch thick, slipped on
to an axis rather smaller than the holes in their centres, but compelled to revolTe with
it by means of what may be termed a planetary axis, which is a rod passing loosely
through holes in the whole series of discs, between their centre and their circamfer-
ence, and so connected with the axis by its ends as to be carried round with it By
this oontriTsnce the upper roller is enabled to adapt its surfhce to that of the skin,
which is ererywhere pressed with an equal force, due to the weight of the discs of
which the upper roller is composed. It is stated in the Peiwy Moffozmi '* that this
machine will split a sheepskin of the ordinary size in about two minutes, during which
time the knife makes from two to three thousand vibratory motions to and fra**
This machine is said to be the iuTention of Lieutenant Parr. Another contrirance
is known as Duxbaiy's Patent Skin Splitting Machine, in which the knife consists of
a series of plates of steel, so attached to the periphery of a wheel or disc, seyenteen
feet in diameter, as to form a gigantic cutting instrument* resembling a crown or
trepan saw, the compound blade projecting horiaontally from the rim of the wheel
parallel to its axis. The skin to be split passes round the circumference of a hori-
sontal drum, the axis of which is at right angles with that of the great disc, and lies
very nearly in the same plane with its face, and which instead of being perfectly
cylindrical has its sides so hollowed as to present a concavity perfectly tiUlying with
the curvature of the periphery of the disc As therefore the drum revolves it brings
the skin, which is confined closely to its concave surfiftce by a contrivance somewhat
resembling the npper roller in the machine above described, in contact with the edge
of the revolving knife, which cuts by a continuous onward movement, instead of a
sawing action Inckwaxds and forwards. The extreme nicety required to fix the con-
cavity of the feeding roller to the edge of the circular knife, and to keep the knife or
cutter itself perfectly true in shape, appear to be the chief objections to this ingenious
cootrivance. — Pamg, C^c, SuppL, Leather,
ExportM of Leather of British Produce and Ifanufacture in 1850 and 1851: —
Quaotitlet. Declared Volae.
£ £
1850. 1851. I85a 1 861.
Leather, unwrought • cwts. 32,205 25,525 181,737 152,070
Wrought, via. gloves - lbs. 31,114 27,141 18,821 19,781
Of other sorts - - lbs. 1,619,463 1,625,565 284,347 288,543
Saddlery and harness . . -- — . 123,960 138,186
It may not be uninteresting to compare these figures with the imports and exports
in 1856 and 1857, ending December 1st.
IwmorU into the United Kingdom: —
1886. 1857.
Hides, dry ... cwts. 219,370 297,783
Hides, salted . - . „ 427,784 16.766
Leather ... lbs. 3,493,589 5,500,010
Boot fronts ... pairs 646,154 606,992
^^kbdT'^^^^^pLnJ ^®^'*®^ *^'*^*
The whole of which are free from import duty, except,
8, d. 9. d.
Boot fronts - - -19 to 29 per dozen pairs.
Women's boots and shoes -46^76 „
Men's do. do. - 7< 0 „ 14 0 „
Exports from the United Kingdom : -*-
Hides, dry ... cwts. 128,952 121,600
Hides, salted . . . „ 37,996 69,413
British Manufaetwe.
Qoantttiet. Declared Talae.
£ £
1866. 1857. 1866. 1857.
Leather, unwrought - cwts. 33,455 34,320 294.703 331,873
Leather, wrought - lbs. 6,931,810 8,090,795 1,122,084 1,700,928
Saddlery and harness. - — — 253,342 294.617
H* M.
LEATHER, VEGETABLE. Under this name a new material, composed of India
rubber spread upon linen, has been introduced. Of this the Mechanic^ Magazine
698 LENS.
inites :— •** HaTing seen some specimens of these leathers, as well as yarioiu artidea of
utility manufactured therewith, we have been induced to pay the exteusive works of
Messrs. Spill and Co., the eminent Goyemment contractors, on Stepney- green, a visit,
in order to cull sufficient to place upon record the present position of artificial as a sub-
stitute for real leather. The face and general character of the vegetable leather
resembles the natural product so closely, that it is only by actual examination that the
difference can be determined. This is more particularly the case in that descriptioa
which is made for bookbinding, the covering of library tables, and like purposesw
Amongst other advantages it possesses over leather proper, may be mentioned, that
however thin the imitation is, it will not tear without considerable force is exercised ;
that it resists all damp, and that moisture may be left upon it for any period withoat
injury* consequently, it does not sodden or cockle, is always dry, and its polish is
rather increased than diminished by friction. Add to these facts, that any attempt to
scratch or raise its surface with the nail, or by contact with any ordinary substance,
will not abrade it, and enough will have been said to justify its entering the list against
an article of daily use, which has of late years been deemed far from sufficient for
the demand, and has consequently risen in price to the manifest loss and injury of every
cbss of the community. We believe that the largest entire piece of real leather that
can be cut from a bullock's hide, is not more than 7 feet by 5 feet, and this includes the
stomach and other inferior parts. Vegetable leather on the contrary, is now produced
50 yards in length, and 1^ yard wide, every portion being of equal and of any required
thickness, and the smallest portion is convertible. We were agreeably disappointed,
however, to find that instead of vegetable leather being a discovery requiring the aid
of ourselves and contemporaries, it was, although so young, an active agent in the
fabrication of numerous articles of daily requirement, and that it had already become
the subject of large, indeed we may say enormous, contracts. Caoutchouc and naphtha
are used in its manufacture ; but by a process known to the senior of the firm, who is
himself an accomplished chemist, all odour is removed from the naphtha, and the smell of
vegetable leather is rendered thereby less in strength, if anything, than that of leather.
The principal objects to which it is at present applied, although it is obvious it will take a
wider range of usefulness than leather itself, are carriage and horse aprons, antigropola,
soldier's belts, buckets which pack flat, harness of every description, bookbinding, &c
For, the latter, its toughness, washable quality and resistance to stains, render it
remarkably fitted. Its thickness, which may be carried to any extent, is obtained by
additional backings of linen, &c., cemented with the caoutchouc, and its strength is
something marvellous, while in the all-important commercial view, it is but one- third
the price of leather. Many of the articles we were shown possessed the appearance
of much elegance and finish ; but it was curious to observe, that although most of
them could be made without a stitch, and within the factory itself, a deference to the
feelings of the workmen in the several trades has been shown by the firm, and the
material is given out as ordinary leather, to undergo the process of the needle, which
it submits to with a greater facility than its original prototype."
LEDUM PALUSTRE. This plant is employed in Russia to tan the skins of goats,
calves, and sheep, into a reddish leather of an agreeable smell; as also in the prepa-
ration of the oil of birch, for making what is commonly called Russia leather.
LEER. An arched building, forming an annealing furnace, in which glass is
tempered or annealled.
LEGUMINE is the name of a vegeto-alkali supposed to exist in leguminous plants.
LEMNIAN EARTH. A yellowish-grey earth, obtained fh>m JLenmos by the
Greeks. It is very similar to fuller's earth.
LEMONS. The fruit of the Citrus limonum. Both the juice and the peel of the
firuit are employed medicinally, and in the preparation of lemonade. The quantity of
lemons imported cannot be ascertained from the Custom House returns, as they are
reckoned together with oranges. See Citric Acn>, and Oils, Essential.
LENS. {Lentilie, Fr. ; Ltjuengku, Germ.) Lenses are transparent bodies, nsnally
made of glass, which by their curvature either concentrate or disperse the rays of
light Lenses are of the following kinds. Double convex, having the same or a
different degree of convexity on either side. Piano convex, having one plane and one
convex surface. Concavo convex, having one concave and one convex side, commonly
called meniscus lenses. Piano concave, having one plane surface and one concave one;
and the double concave lens.
The first three, which are thicker in the middle than at the edge, are converging
lenses, because they occasion the rays of light to converge in passing through them.
The others which are thicker at the edges than in the middle, and therefore cause the
pencils of light refhicted through them to diverge, are called diverging lenses.
For the most complete examination of the laws regulating the construction of lenses,
and the action of these on the rays of light we must refer the reader to Sir John
LENS. 699
Henchel's admirable treatise on Zig^ in the Encyclopedia Meiropolitana. In this irork
we baTe only to deal with the mode of manufkctunng the ordinary Tarieties. The
tpberical surfaces are produced by grinding them in counterpart tools, or discs of
metal, prepared to the same curvature as the lenses. For the formation of the grind-
ing tools, a concave and a convex template are first made to the radius of the curva-
ture of the required lens. The templates of large radius, are sometimes cut out of
crown glass. More usually the templates are made out of sheet brass, the templates
of long radii ere cut with a strong radius bar and cutter, and those of only a few
inches radius are cut in the turning lathe. The brass concave and convex gauges are
cut at separate operations, as it is necessary to adjust the radius to compensate for the
thickness of the cutter, and the brass templates are not usually corrected by grinding,
as practically it is found more convenient to fit Uie tools themselves together. The
templates having been made of the required radius, are used for the preparation of the
grinding and polishing tools, which for concave lenses consist of a concave rough
grinding tool of cast iron called a shelL
A pair of brass tools is however the most unportant part of the apparatus. One of
these is concave and the other convex, made exactly to the curvature of the templates
and to fit each other as accurately as possible. The concave tool is used as the
grinder for correcting the curvature of the lenses after they have been roughly figured
in the concave shell, and the convex tool is employed for prodacing and maintaming
the true form of the concave grinding tool itself, and also that of the polisher. These
polishers are adjusted with great accuracy. The concave tool is placed upon the
convex, and they are first rubbed together dry, so that by the brightened parts the
inequalities may be distinguished, they are then ground true, first by means of emery
and water, and then with dry emery.
The following figure (1180) represents those tools, which are fitted with screws at
the back so that they can be fixed upon pillars, in coonec* j j3q
tion with the machinery for giving motion to them.
By grinding with sundry niceties of motion which are
required to produce the best effect, such as the production
of motion which shall resemble as nearly as possible the
kind of stroke which would be given by the hand, these
tools are eventually brought to true spherical figures
which fit each other exactly.
The glasses for lenses, being selected of suitable quality,
they are brought to a circular form by means of flat pliers
called ghastks. The pressure of the pliers applied near the
edges of the glass causes it to crumble away in small
firagments, and this process, which is called shanking or nibbling, is continued until the
glasses are made circular, and of a little larger diameter than the finished size of the
lenses.
A cement is made by mixing wood ashes with melted pitch. Some nicety is required
in the a<i|justment of the proportion, since the cement must not be too adhesive, nor must
it be too hard or too brittle ; genendly about 4 lbs. of wood ashes to U lbs. of pitch are
employed. This when melted is poured on one side of the glasses to be ground, in
small quantities at a time, until a sufficient quantity adheres to the back of the lens
to form a handle. The £^ass is rough ground by rubbing it within the spherical
shell. The glass is rubied with large circular strokes, and the shell is usually placed
within a shidlow tray to catch the loose emery or polishing powder which may be
employed. When one side is rough ground in this way, the glass is warmed to detach
it f^om the handle, which is transferred to the other side and the operation repeated.
When both sides are thus rudely formed, the lenses are cemented upon a runner.
The best object glasses for telescopes are ground and polished singly, while as many
as four dozen of common spectacle glasses are grocmd and polished together. When
many are thus fixed on one runner, the number must be such
as will admit of their being arranged symmetrically around ]} \
a central lens, as 7, 13, or 21, or sometimes 4 form the nucleus,
and then Uie numbers run 14, 80. Lenses of ordinary quality
are usually ground true and polished seven at a time. This
runner with its lenses attached is shown in^^. 1131.
The cement at the back of the lenses is first flattened with a heated iron. The
cast iron runner is heated just sufficiently to melt the cement, and carefully placed
upon the cemented backs of the lenses. As soon as the cement is sufficiently softened
to adhere firmly to Uie runner, it is cooled with a wet sponge, as the cement must only
be so fkT fused as to fill up the spaces nearly, but not quite, level with the surface of
the lenses. The block of lenses is now mounted upon a post, and ground with the
concave brass tool,^. 1130, motion being given to it either by the hand or by
700 UAS.
machinery similar to the sireeping motion already named. As the grinding proceeds,
the fineness of the emery powder employed is increased, nntil in the last operation it
is snfficiently fine to prodace a semi-polished surface. This grinding being com-
pleted successftilly, the lenses haye to be polidied. The polisher is made by warming
a cast iron shell and coating it uniformly about one quarter of an inch thick with
melted cement. A piece of thick woollen cloth is out to the size of the polisher and
secured to it, and pressed into form by working the brass tool within it. When
this is properly adjusted it is covered with very finely divided pntty'powder, sprinkled
with a little water, and the powder worked into the pores of the cloth with the brass
convex tool. Repeated supplies of putty powder is put on the polisher ontil it is
made quite level, and it is worked smooth with the tool. Many hours are expended
in the proper preparation of a polisher. When completed it is placed upon the block
of lenses still fixed to the poet, and worked with wide and narrow elliptical strokes
Where a very large number of glasses are ground or polished at the same time, this
peculiar motion is imitated by the eccentric movement of a lever attached to the
revolving shaft In the processes of grinding and polishing, other materials beside
emery and putty powder are sometimes employed, such as raddle, an earthy oxide of
iron, the finer kinds of which are much employed in the large lens manufiustory at
Sheffield.
Much more might be said on the subject of grinding and polishing lenses, but
it is one of those processes of manufacture which scarcely come within the limits of
the present work. Still it was thought to be of sufficient importance to receive some
general notice. The grinding and polishing of the finer varieties of lenses for tele-
scopes, microscopes, and the like, require extremely nice manipulation. The best
account of the processes and of the instruments used is one by the late Andrew BUms
in the fifty -third volume of the TYansaetiotu of the Society q/* Arts, In BoUzapffett
Mechanical Manipulation there is also some very excellent practical information.
See LiOHTHOUSE ; Photogbapht.
LEPIDINE, C*H'N. A volatile base, homologous with chinoline, found in coal
naphtha and in the fluid produced by distilling cinchonine with potash. — C. G. W.
LEUCITEL A mineral found in volcanic rocks, containing usually 56-10 of
silica, 23' 10 of alumina, and 21*15 of potash.
LEUCOLINE. A compound of C**H'N, produced during the destructive distil-
lation of coaU See Coal Gas.
LEUKOL. See Chinolinb.
LEVEL (a mining term). An adit gallery or horizontal working in a mine.
LEVIGATION is the mechanical process whereby hard substances are reduced
to a very fine powder.
LEWIS is the name of one kind of shears used in cropping woollen cloth.
LIAS. Under this term are comprehended the strata whidi intervene between the
Trias, or New Red Series, and the Inferior Oolite. In the aggregate they are of
considerable thickness, and occupy a large area in this country, stretching in a north-
easterly direction frem the sea west of Lyme Regis, in Dorsetshire, to Redcar, on the
coast of Yorkshire. The strata which compose the Liassic series consist, in the lower
part, of compact argillaceous limestone, alternating with or forming iayere in clay, to
a provincial pronunciation of which word the name li€u probably owes its origin.
This limestone forms the base of a thick deposit of blue clays and marls, which are
overlaid by a series of sands and sandstone, called Marlstone; these in their 4om, are
separated from another mass of sands, which form the uppermost member of the
group, by a stratum of clay, known as the Upper Lias Clay.
By the term lias, however, is ordinarily only understood the calcareous and argil-
laceous division, wluch constitutes the lower section of the entire formation.
In an economical point of view, it is of considerable value from its furnishing a
useful and durable stone, both for building and paving ; for the latter purpose it is
particolarlv suited, not only from the large dimensions of the flags it affords, but oa
account of its occurrence in thin layers, which, in many cases, when required for
rough purposes only, are used in the state in which they are taken firom the quarry,
without undergoing subsequent dressing. The lime furnished by the blue lias limestone,
is also well known, and in great request, some of the beds possessing the valuable pro-
perty of forming hydraulic mortars and cements, for manufieicturing which it is col-
lected from the shore and the sea cliffs at Charmouth, and largely quarried at Lyme
Regis and the neighbourhood.
The clayey members of the lias furnish a poor and cold agricultural soil, which is
chiefly devoted to pasture, but the land upon the marlstone is, on the contrary, of a
very rich and ferdle description, and constitutes a district, where it prevails, that is
marked by the luxuriance of its crops, and the excellence of the cider it produces.
In the upper part, it contains beds of ferruginous, brown, calcareous sandstone, which
LICHEN. 701
18 used for building pnrpofles in the neighbonrhooda where it occurs. The aandstone
is always more or less of a fermgiDous character, bat in some instances the fermginons
ingredient prevails to such a degree, as to constitute a valuable ore of iron, as in the
neighbourhood of Blenheim, to which attention has lately been directed by Mr.
Edward Hull, of the geological survey of Great Britain.
Like the marlstone, the calcareous sands of the uppermost portion of the liassio
series also furnish a rich agricultural soiL Until recently, these sands were consi-
dered to form the base of the inferior oolite series, but the researches of Dr. Wright,
render it hiffhly probable that they should, with more propriety, be classed wiUi the
underlying lias, rather than with the oolitic strata.*
Th« stone found at Gotham and other places in the neighbourhood of Bristol, and
which has in consequence received the name of Cotham marble^ and has also been
called nrtn, or landscape marble, from the curious delineations displayed upon polished
sections of it, resembhng trees, landscapes, &C., is a limestone fh>m tiie lower part of
the lias.— H. W. B.
LIB AVIUS, FumRG Liquob of, is the bichloride of tin, prepared by dissolving
that metal with the aid of heat in aqua regia, or by passing chlorine gas through a
bolution of muriate of tin till no more gas be absorbed, evaporating the solution, and
setting it aside to crystallise. The anhydrous bichloride is best prepared by mixing
four parts of corrosive sublimate witii one part of ^ tin, previously amalgamated
wiih just so much mercury as to render it pulverisable ; and by distilling this
mixture with a gentle heat A colourless fiuld, the dry bichloride of tin, or the
proper ftiming liquor of Libavius, comes over. When it is mixed with one-third of'
its weight of water it becomes solid. The first bichloride of tin is used in calico-
printing. See Cauco-pbihtimo.
LICUEN. A certain set of plants, composed chiefly of cellular tissue devoid of
spinal vessels, with the stems and leaves undistinguishable, are termed Thallogens.
These are of two kinds, Uie first admitting of two divisions : —
1. Aquatic thallogens, or such as are nourished through their whole surface by
water, are Aixmb. Aerial thallogens nourished through their whole surface by air
are Lichens.
2. Thallogens nourished through their thaUue (spawn or mycelium) by juices
derived from the matrix are Funol
Lichens are numerous, as Ground liverwort. Cup mostf Tree lungwort, used in
Siberia as a substitute for hops in brewing ; Gyrophora employed by the hunters in
the arctic regions as an article of food, under the name of tripe de roche ; Reindeer
WW89, Iceland mots, much used in this country as a remedy for coughs ; the Common
yellow wall lichen, and some others.
The Tinctorial Hehene are also numerous. They furnish four principal colours,
brown, yellow, purple, and blue.
Gyrophora pustuUita and Sticta puhnonaria yield brown colours. The latter, with
mordants of tin and cream of tartar, produces on silk a durable carmelite colour.
iGuibourt)
Pamulia parietina and Evemm vulpina produce yellows, the yellow principle of
the former being called ehryeophanie acid, that of the latter vulpinic acid.
Rocella^ Lecanora, Varidaria, &c., yield purple and blue colours. In this country
archil and cudbear, purple colours, are prepared. In Holland, a blue colour, litmus.
The following is a list (from Pereira} of the principal lichens employed by British
manu&cturers of archil and cudbear, with their commercial names : —
Barbary (Mogadore) (JR. tinctoria),
Corsican and Sardinian „
OBCHEIXA WEEDS.
Angola Orchella weed {R. Juciformie),
Madagascar „ ,>
Mauritius „ «f
Canary « (A tinctoria).
Cape de Verd „ n
Azores „ n
Madeira „ (ditto and/uciformi*).
South America, large and round (R, tinctorial
South America, small and flat iR.fueiformis),
Cape of Good Hope {R, hypomccka).
Dr. Stenhouse, to whom we are much indebted for many important inquiries con-
nected with the applications of chemistry, has given the following table of the lichens : —
• The evidence brought foward by Dr. Wright In fkvour of the llaitlc origin of these undt it purrlv
of a paiflBontological nature ; physically, the most n^ral arrangement is to connect them rather with
the inferior ooUte than with the lias— H. W. B.
MOSSES.
Tartareous (^Lecanora tartarca),
Postulatus ((jryrophora pustu'atd).
Canary Rock \Parmelia perlata),
Corsican.
Sardinian.
Norway Rock Moss.
702
LIGHT.
Llehcni.
ColorUlc PriaciplM.
C«loaitaff Prtnclpte.
AvOmgitj.
CommcKUl NamcB.
Leodlcy.
NUBM.
FonmilM.
Namm.
Foraml«.
& American or-
Lima, Ac.
Alpha ortel-
CSiHiSQis+HO.
Orcelne.
CWH»«»NO.
Stenbouae.
chelU wmnI.
tic acid.
Cape orchdia weed
Cor Good
Hope.
Beta oreel-
lic acid.
CS4H»0<4+HO.
tt
ft
StOBboasc.
Angola orcbella
Africa.
Erythric
C»H100*+HO.
ft
n
Stenfaooae.
weed.
acid.
Perellfl roou (Xe-
Swltserland
Lecanoric
C»8H«0«.
ft
M
Shunek.
canora paretia.)
acid.
Tartareout inots
Norway.
Oyrophorlc
0>«H»«O».
#•
ft
Stenbooae.
( I^eamora tar-
tar ea.)
PuitulatoQt moM
acU.
Norway.
M
n
t*
»t
StODbooacL
(Gwrophorafm-
tufata).
Raaged hoary li-
chen (Bvemta
Scotland.
ETemie
C»*H»oa+HO.
.
.
Scenhooae.
add.
prunattri).
V»neH(FiorUa,pU.
0«nnany.
Unlcadd.
C»H70".
.
•
RochledM-
catcandkiria).
andHeidt.
RHn deer most
m m
n
tt
a
•
M
(Cladomaramgi'
ferina). ^
Ramalina (Fasti"
m •
w
M
m ^
m
n
giata eaUcaris).
See Litmus, Orchella Wexd.
LICKNER'S BLUE. The SiUcale of Cobalt and Potasb.
LIGHT. (LumOre^ Fr. ; Liekt, Germ.) The operation of light aa an agent in
the arts or manofaactares has scarcely yet received attention. Sufficient eridenoe
has however been collected to show that it is of the atmost importance in prodnciog
manj of the remarkable changes in bodies which are desired in some eases as the
result, but which, in others, are to be if possible avoided.
There is a very general misconception as to the power or principle to which cer-
tain phenomena, the result of exposure to sunshine, are to be referred. In general
light is regarded as the principle in action, whereas frequently it has nothing what-
ever to do with the change. A few words therefore in explanation are necesaary.
The solar ray, commonly spoken of as Kgktf contains in addition to its IwminomM power,
calorific poweTf chemical power, and in all probability deeirical power. (See AcmnsM.)
These phenomena can be separated one fi^m the odier, and individually studied. AU
the photographic phenomena are dependent upon the chemical (actinic) po«er.
Many of the peculiar changes which are effected in organic bodies are evidently doe
to light, and the phenomena which depend entirely on heat are well known.
Herschel has directed attention to some of the most striking phenomena of H^/kL,
especially its action upon vegetable colours. As these have direct reference to the
permanence of dyes, they are deserving of great attention. The following qaotation
from Sir John Herschers paper '* On the Chemical Action of the Eatfe ^ the Solar
Spectrum, ^v." will explain his views and give the character of the phenomena which
he has studied. He writes —
" The evidence we have obtained by the foregoing experiments of the existence of
chemical actions of very different and to a certain extent opposite characters at the
opposite extremities (or rather as we ought to express it in the opposite regions) of
the spectrum, will naturally give rise to many interesting speculations and conclu-
sions, of which those I am about to state, will probably not be regarded as among the
least so. We all know that colours of vegetable origin are usually considered to be
destroyed and whitened by the continual action of light The process, however, is
too slow to be made the subject of any satisfactory series of experiments, and, in
consequence, this subject, so interesting to the pamter, the dyer, and the general
artist, has been allowed to remain uninvestigated. As soon, however, as these evi-
dences of a coimterbalance of mutually opposing actions, in the elements of which the
solar light consists, offered themselves to view, it occurred to me, as a reasonable
subject of inquiry, whether this slow destruction of vegetable tints might not be due to
the feeble amount of residual action outstanding after imperfect mutual compensation,
in the ordinary wav in which such colours are presented to light, t. e. to mixed nyn.
It appeared dierefore to merit inquiry, whether such colours, subjected to the un-
compensated action of the elementary rays of the spectrum, might not undergo
changes differing both in kind and in degree which mixed light produces on them,
and might not, moreover, by such changes indicate chemical properties in the rays
themselves hitherto unknown.
" One of the most intense and beautiful of the vegetable blues is fhat yielded by the
LIGHT. 703
bine petals of the dark reUety Tarieties of the common heartsease (Viola tricolor). It
is best extracted by alcohol. The alcoholic tincture so obtained, after a few days keep-
ing in a stoppered phial, loses its fine blue colour, and changes to a pallid brownish
red, like that of port vine discoloured by age.
" When spread on paper it hardly tinges it at first, and might be supposed to have
lost all colouring rirtue, but that a few drops of Tery dilute sulphuric acid sprinkled
over it, indicate by the beautiful and intense rose colour dereloped where they fidl,
the continued existence of the colouring principle. As the paper so moistened with
the tincture dries, however, the original blue colour begins to appear, and when quite
dry is full and rich. The tincture by long keeping loses this quality, and does not
seem capable of being restored. But the paper preserves its colour well, and is eren
rather remarkable among vegetable colours for its permanence in the dark or in
common daylight.
** A paper so tinged of a very fine and fhll blue colour, was exposed to the
solar spectrum concentrated, as usual (October 11, 1839), by a prism and lens; a
water-prism, however, was used in the experiment, to command as large an area of
sunbeam as possible. The sun was poor and desultory $ nevertheless in half an hour
there was an evident commencement of whitening from the fiducial yellow ray to the
mean red. In two hours and a half, the sunshine continuing very much interrupted
by clouds, the effect was marked by a considerable white patch extending from the
extreme red to the end of the violet ray, but not traceable beyond that limit. Its com-
mencement and termination were, however, very feeble, graduating off insensibly }
but at the maximum, which occurred a little below the fiducial point (corresponding
nearly with the orange rays of the luminous spectrum), the blue colour was completely
discharged. Beyond the violet there was no indication of increase of colour, or of any
other action. I do not find that this paper is discoloured by mere radiant heat
unaccompanied with light."
Dr. George Wilson of Edinburgh made some exceedingly interesting experiments
an the injluence of nm light over Ae action o/the dry gases on organic colours. The
results arrived at were conmiunicated to the British Association, and an abstract of
the communication is published in their transactions. The experiments were on
chlorine, sulphurous acid, sulphuretted hydrogen, carbonic acid, and a mixture of
sulphurous uid carbonic acid, oxygen, hydrogen and nitrogen on organic colouring
maitera. ** I had ascertained,'' says 1>r. George Wilson, *' the action of the gases
mentioned already on vegetable colouring matters, so arranged, that both colouring
matter and gas should be as dry as possible, the aim of the inquiry being to elucidate
the theory of bleaching, by accounting for the action of dry chlorine upon dry colours.
In the course of this inquiry, I ascertained that in darkness dry chlorine may be kept
for three years in contact with colours without bleaching them, although when moist
it destroys their tints in a few seconds (see Bi«eachimo) ; and I thought it desirable
to ascertain whether dry chlorine was equally powerless as a bleacher when assisted
by sunlight. The general result of the inquiry was, that a few weeks sufficed for the
bleaching of a body by chlorine in sunlight, where months, I may even say years,
would not avail in darkness." The form of the experiment was as follows. Four
tubes were connected together so as to form a continuous canal, through which a
current of gas could be sent Each tube contained a small glass rod on which seven
pieces of differently coloured papers were spiked. It is not necessary here to state
the colours employed, suffice it to say, that all the tubes thus contained seven different
coloured papers, of different origins, and easily distinguishable by the eye. They
were arranged in the same order in each tube, and were prepared as nearly as
possible of the same shade. These papers were careftdly deprived of every trace of
moisture by a current of very dry air. The tubes were then filled with the gas, also
dried, on which the experiment was to be made. One tube of each series was kept
in darkness, two others were exposed in a western aspect behind glass, and the other
was turned to the south in the open air.
The results were as follows : ^ In the dark chlorine tube the colours were very
little altered, and would probably have been altered less had not the tube been fre-
quently exposed to light for the sake of examination. In the western tube, the
original grey and green wallflower papers became of a bright crimson, the blue
litmus bright red, and the brown rhubarb yellow. The whole of the chlorine had
apparently entered into combination with the colouring matters for the vellow tint of
the gas had totally disappeared. In the southern tube the colour of the cnlorine could
still be seen, the reddening action was less decided, and the bleaching action was
more powerfully evinced. The general result was that the action of sunlight is less
uniform than might have been expected in increasing the bleaching power of chlorine,
or while some tints rapidly disappeared under its action assisted by light, other colours
remained, in apparently the very same circumstances, unaffected.
704 LIGHTHOUSE.
Sulphurous acid^ if thoronghly dried, may be kept for months in contact vith dry
coloars without altering them ; under the influence of sunlight it however recoTeTs to
some extent its bleaching power.
SulphureUed hydrogen acts as a weak acid, and readily as a bleacher when moist,
and becomes inactive in both respects if made dry and kept in darkness. With the
assistance of sunlight it recovers in no inconsiderable degree its bleaching power.
Oxygm is a well known bleaching agent, but when dry its action upon colouring
matter in the dark is extremely slow. Ju sunlight, however, it recovers its bleaching
power.
Carbonic acid, when dry in darkness, loses all power on colouring matter, but a
faint bleaching action is exerted by it under exposure to sunlight.
Hydrogen is without any action when dry upon colours, bat it acquires a slight
decolorising power when exposed to sunshine.
" The general result," concludes Dr. George ¥^8on, *' of this inquiry, so &r as
it has yet proceeded, is, that the bleaching gases, viz. chlorine, sulphurous acid,
sulphuretted hydrogen, and oxygen, lose nearly all their bleaching power, if dry and
in darkness, but all recover it, and chlorine in a most marked degree, by exposure to
sunlight"
All these experiments appear to show that the action of the solar rays on vegetable
colours is dependent upon the power possessed by one set of rays to aid in the
oxidation or chemical changes of the organic compound constituting the cokmring
matter. The whole matter requires careful investigation.
It is a proved fkct, that colouring matters, either from the mineral or the vegetable
kingdoms, are much brighter when they are precipitated from their solutions in
bright sunshine, than if precipitated on a cloudy day or in the dark. It muai
not be supposed that all the changes observed are due to chemical action; there
can be no doubt but many are purely physical phenomena, that is, the result of mole-
cular change, without any chemical disturbance.
LIGHT, ELECTRIC. See Electric Light.
LIGHTHOUSE. The unportance of lights of great power and of a disdnguish-
able character around our coasts is admitted by alL (hie of the noblest efforts of
humanity is certainly the construction of those guides to the mariners upon rocks
which exist in the tracks of ships, or upon dangerous shores and the months of har-
bours. This is not the place to enter largely upon any special description of the
lights which are adopted around our shores; a brief account only will be given of some
of the more remarkable principles which have been introduced of late years by the
Trinity Board.
The early lighthouses appear to have been illuminated by coal or wood fires con-
tained in " chauffers." The Isle of Man light was of this kmd until 1816. The first
decided improvement was made by Argand, in 1784, who invented a lamp with a
circular wick, the flame being supplied by an external and internal current of air.
To make these lamps more effective for lighthouse illumination, and to prevent the
ray of light escaping on all sides, a reflector was added in 1780 by M. Lenoir; this
threw the light forward in parallel rays towards such points of the horixon as would
be useful to the mariner. Good reflectors increase tiie luminous effect of a lamp
about 400 times ; this is the " catoprio ** system of lighting. When reflectors are
used, there is a certain quantity of light lost, and the ** dioptric*' or rrfracting system.
invented by the late M. Angastin Fresnel in 1822 is designed to obviate this effect to
some extent: the ** catadioptric " system is a still further improvement, and acts both
by refraction and reflexion. Lights of the first order have an interior radius or focal
distance of 36*22 inches, and are lighted by a lamp of four concentric wicks, con-
suming 570 gallons of oil per annum.
The appearance of light called short eclipses has hitherto been obtained by the
following arrangement: —
An apparatus for a fixed light being provided, composed of a central cylinder and
two zones of catadioptric rings forming a cupola and lower part, a certain number of
lenses are arranged at equal distances from each other, placed upon an exterior
movable frame making its revolution around the apparatus in a given period. These
lenses, composed of vertical prisms, are of the same altitude as die cylinder, and the
radius of their curves is in opposite directions to those of the cylinder, in such a
manner that at their passage Uiey converge into a parallel pencil of light, all the
divergent rays emitted horizontally from the cylinder producing a brilliant effect,
like that obtained by the use of annular lenses at the revolving lighthouses.
Before proceeding with the description of the lenses, the following notices may be of
interest : —
The Eddystone Lighthouse 9^ miles from the Rame Head, on the coast of C<im-
wall, was erected of timber by Winstanley in 1696-98, and was vraahcd away in
LIGHTHOUSE.
705
1708. It was rebuilt by Radyard in 1706, and destroyed by fire in 1755. The pre-
sent edifice was erected by Smeaton 1757-59. Tallow candles were used in the first
instance for the lights; bat in 1807 argand lamps, with paraboloidal reflectors of
silvered copper were substituted. »
The SkerryTore Rocks, about 12 miles south-west of Tyree on the coast of Argyle-
shire, lying in the track of the shipping of Liverpool and of the Clyde had long been
regarded with dread by the mariners frequenting these seas. The extreme difficulty
of the position, exposed to the unbroken force of the Atlantic Ocean, had alone de-
terred the conmiissioners of northern lights from the attempt to place a light upon
this dangerous spot; but in 1834 they caused the reef to be surveyed, and in 1888
Mr. Alan Stevenson, their engineer, inheriting his fiitber*s energy and scientific skill,
conunenced his operations upon a site from which ** nothing could be seen for miles
around but white foaming breakers, and nothing could be heard but the howling of
the winds and the lashing of the waves." His design was an adaptation of 8meaton*s
tower of the Eddystone to the peculiar situation, a circumstance with which he had
to contend. He established a circular base 42 feet in diameter, rising in a solid
mass of gneiss or granite, but diminishing in diameter to the height of 26 feet, and
presenting an even concave surface all around to the action of the waves. Imme-
diately above this level the walls are 9*58 feet thick, diminishing in thickness as the
tower rises to its highest elevation, where the walls are reduced to 2 feet in thickness,
and the diameter to 16 feet The tower is built of granite firom the islands of Tyree
and Mull, and its height from the base is 138 feet 8 inches. In the intervals lere by
the thickness of the walls are the stairs, a space for the necessary supply of stores,
and a not uncomfortable habitation for ^ree attendants. The rest of the establish-
ment, stores, &c., are kept at the depot in the island of Tyree. The light of the
Skerryvore is revolving, and is produced by the revolution of eight annular lenses
around a central lamp, and belongs to the first order of dioptric lights in the system
of Fresnel, and may be seen from a vesseFs deck at a distance of 18 miles. —
Lord De Mauley, Juror's Report, Great Exhibition, 1851.
Some of the lenticular arran^ments must now claim attention. Large lenses, or
any large masses of glass, are liable to strise, which by dispersing, occasion a loss of
much light
'* In order to improve a solid lens formed of one piece of glass whose section
is A, 91, p, B, F, E, j>, c, A, Bu£fon proposed to cut out all the glass left white in the
figure (1132), namely, the portions between m p and n o, and between n o and the
left hand surface of de. A lens thus constructed would be incomparably superior
to a solid one, but such a process we conceive
to be impracticable on a large scale, fh>m the
extreme difficulty of polishing the surfaces
A fli, B />, c f c, F o, and the left hand surfince of
i> e; and even if it were practical, the greatest
imperfections of the glaiss might happen to
occur in the parts which are left. In order
to remove theae imperfections and to construct
lenses of any size," says Sir David Brewster,
** I proposed in 1811 to build them up of sepa-
rate zones or rings, each of which rings was
again to be composed of separate segments, as
shown in the front view of the lens in Jig. 1183. This lens is composed of one cen-
tral lens A B c D, corresponding with its section d e mfig. 1133 ; of a middle ring
o E L I, corresponding to c d e f, and consisting of 4 segments; and another ring
N p B T,. corresponding to A c f b, and consisting of 8 segments. The preceding
construction obviously puts it in our power to execute those lenses to which I have
given the name of polyzonal Unut, of pure flint glass free from veins ; but it possesses
another great advantage, namely, that of enabling us to correct very nearly the
spherical aberration by making the foci of each zone coincide." — Brewster,
This description will enable the reader to understand the system which has been
adopted by Fresnel and carried out by the French government, and by our own com-
missioners of lights.
In the flxed dioptric light of Fresnel, the flame is placed in the centre of the ap-
paratus, and within a cylindric reflector of glass, of a vertical refracting power, the
breadth and height of a strip of light emitted by it being dependent upon the size of
the flame and the height of the reflector itself ; above and below is placed a series of
reflecting prismatic rings or zones for collecting the upper and lower divergent rays,
which, felling upon the inner side of the zone are refracted, pass through tibe second
side where they suffer total reflection, and, passing out on the outer side of the zone«
are again reftucted. The effect of these zones is to lengthen the vertical strip of
Vol. IL Z Z
1132
706 LIGHTHOUSE.
light, the Biie of which U dependent upon the breadth of the flame and the height of
the apparatOB.
In Freanel's reTolving lighthowe, a large flame » placed in the centre of a reTolr-
ing frame which carries a number of lenses on a large scale and of Tarioos carva-
tures for the avoidance of spherical aberration. With the yiew of eolleeting the
divergent rays above the fiame, an arrangement of lenses and silvered mirrors is
placed immediately over it. By this compound arrangement the simply revolving
character of the apparatus is destroyed, as, in addition to the revolving flash, a ver>
tical and fixed light is at all times seen, added to which a great loss of light must be
sustained by the loss of metallic reflectors. In 1851, Messrs. Wilkins and Letour*
neau, exhibited a catadioptric apparatus of great utility. It was thus described by
the exhibitors : —
The first improvement has special reference to the light, and produces a consider-
able increase in its power, whilst the simplicity of the optical arrangements is also
regarded. It consists, firstly, in completely dispensing with the movable central
cylindrical lenses ; secondly, it replaces these by a single revolving cylinder composed
of four annular lenses and four lenses of a fixed light introduced between them ; but
the number of each varying according to the succession of flashes to be produced in
the period of revolution.
The second improvement, of which already some applications that have been made
serve to show the importance, consists in a new method of arranging the revolving
parts, experience having shown that the arrangements at present in use are Tery faulty.
A short time is sufficient for the action of the friction rollers, revolving on two
parallel planes, to produce by a succession of cuttings a sufficiently deep grooTe to
destroy the regularity of the rotatory movement To obviate this great inconvenience
the friction rollers are so placed and fitted, on an iron axis with relating screws and
traversing between two bevelled surfaces, that when an indentation is made in one
place they can be adjusted to another part of the plates which is not so worn.
The third improvement produces the result of an increase of the power of the flashes
in revolving lighthouse apparatus to double what has been obtained hitherto. By
means of lenses of vertical prisms placed in the prolongation of the central annular
tenses, the divergent rays emerging from the catadioptric zone are brought into a
straight line, and a coincidence of the three lenses is obtained.
The whole of the prisms, lenses, and aones are mounted with strength and sim-
plicity, accurately ground and polished to the correct curves according to their re-
spective positions, so as to properly develope tbis beautiful system of FresneL The
glass of which they are composed should be of the clearest crystal colour, and free
fVom that green hue which so materially reduces the power of the light, and is con-
sidered objectionable for apparatus of this kind. The lamp by which the apparatus is
to be lighted consists of a concentric burner with four circular wicks attached to a
lamp of simple construction, the oil being forced np to the burner by atmospheric
pressure only, so that there are no delicate pumps or machinery to become deranged.
Stevenson* t revolving lighthouse. — This apparatus consists of two parts. The prin-
cipal part is a right octagonal hollow prism composed of eight large lenses, which
throw out apowerfhl beam of light whenever the axis of a single lens comes in the line
between the observer and the focus. This occurs once in a minute, as the frame which
bears the lens revolves in eight minutes on the rollers placed beneath. The subsidiary
parts consist of eight pyramidal lenses inclined at an angle of 30^ to the horiaon, and
forming together a hollow truncated cone, which rests above the flame like a capu
Above these smaller lenses (which can only be seen by looking from below) are
placed eight plane mirrors, wbose surfaces being inclined to the horizon at 50° in the
direction opposite to that of the pyramidal lenses, finally cause all the light made
parallel by the refraction of these lenses to leave the mirror in a horizontal direction.
The only object of this part is to turn to useful account, by prolonging the duration
of the flash, that part of the light which would otherwise escape into the atmosphere
above the main lenses. This is effected by giving to the upper lenses a slight hori-
zontal divergence from the vertical plane of the principal lenses. Below are five
tires of totally reflecting prisms, which intercept the light that passes below the great
lenses, and by means of two reflexions and an intermediate refraction prefect them in
the shape of a flat ring to the horizon.
S*evenson*8 fixed dioptric apparatus of the first order (same as that at the Isle of
May, with various improvements). The principal part consists of a cylindric belt of
glass which surrounds the flame in the centre, and by its action refracts the light in
a vertical direction upward and downward, so as to be parallel with the focal plane of
the system. In this way it throws out a flat ring of light equally intense in every
direction. To near observers, this action presents a narrow vertical band of light.
LIGNITE.
707
depending for its breadth on the extent of the horizontal angle embraced by the eye.
This arrangement therefore fulfils all the conditions of a fixed light, and surpasses in
effect any arrangement of parabolic reflectors. In order to save Uie light which would
be lost in passing above and below the cylindrical belt, curved mirrors with their
common focus in the lamp were formerly used ; but by the present engineer, Uie
adaptation of catadioptrw cones to this part of the apparatus was, after much labour,
successfully carried out These tones are triangular, and act by total reflexion, the
inner face re/ntcting, the second tottJIy r^tctiHg, and the third or outer face, a second
time refracting, so us to cause the light to emer^ horizontally. The apparatus has
received many smaller changes by the introduction of a new mode of grouping the
various parts of the framo work, by which the passage of the light is less obscured in
every azimuth.
Mechanical lamps of Ibnr wicks, are used in these lighthouses ; in these the oil is
kept continually overflowing by means of pumps which raise it from the cistern below ;
thus the rapid carboniBation of the wicks, which would be caused by the great heat,
is avoided. The flames of the lamp reach their best effect in three hours after light-
ing, i. e, after Che whole of the oil in the cistern, by passing and repassing over the
wicks repeatedly, has reached its maximum temperature. After this the lamp often
bums 14 hours without sensible diminution of the light, and then rapidly falls. The
height varies from 16 to 20 times that of the argand flame of an inch in diameter ;
and the quantity of oil consumed by it is greater nearly in the same proportion.
In Steventon's ordinary parabolic r^ecior, rendered holophottU (where the entire
light is parallelised) by a portion of a catadioptric annular lens, the back part of the
parabolic conoid is cut off, and a portion of a spherical mirror substituted, so as to
send the rays again through the flame; while his hohphotal catadioptric annular lent
apparatus is a combination of a hemispherical mirror and a lens having totally-reflect-
ing zones ; the peculiarity of this arrangement is, that the catadioptric zones, instead of
transmitting the light in parallel horizontal plates, as in Fresnel's apparatus, produces,
as it were, an extension of the lenticular or quaquaversal action of the central lens by
assembling the light around its axis in the form of concentric hollow cylinders.
Mr. Chance, of Birmingham, constructed a lighthouse which may be regarded as
Fresnel's revolving light rendered holophotal. This arrangement was divided into
three compartments, the upper and lower of which were composed respectively of
thirteen and six catadioptric zones which produce the vertical strip of light extending
the whole length of the apparatus, and is similar to Fresnel's dioptric light The
central or catoptric compartment consisted of eight lenses of three feet focal length,
each of which was the centre of a series of eleven concentric prismatic rings, designed
to produce the same retractive effect as a solid lens of equal size. These compound
lenses were mounted npon a revolving frame and transmitted horizontal flashes of light
as they successively rotated. The motion was communicated to the frame by a clock
movement, and performs one revolution in four minutes ; consequently, as there are
eight lenses, a flash of light is transmitted every thirty seconds to the horizon.
LIGNEOUS MATTER is vegetable fibre. See Fibre Vbobtablb.
LIGNITE. Under BboWn Coal, Boghead Coai^ and Coal, the characteristics of
lignite have already received attention, therefore little further need be said. The
term lignite should be confined to fossil wood, or, still more correctly to wood which
has undergone one of the changes leadiug towards the production <Tf coal. If wood is
buried in moist earth there is the production of carbonic acid from the elements of the
wood, and the wood is changed into either lignite or brown coaL Lignite and coal
differ chemically from each other. Lignite yields by dry distillation acetic acid and
acetate of ammonia, whereas coal produces only an ammoniacal liquor. (Kremers.^
Woody fibre gives rise to acetic acid; therefore, lignite must still contain nndecomposed
woody fibre. The following table gives the composition of several well known
lignites.
From Uttweiler -
„ Hungary -
„ the Rhone -
H Meissner -
„ Bovey Heathfield-
CarboxL
Hydrogen.
Oxygen and
Nitrogen.
Earthy
matter.
ChenUt.
77-9
67-3
72-2
686
67-9
2-6
4-3
4*9
5-9
S8
19-5
20 1
19 0
24-8
1
0-8
18
2-3
Karsten
Nendiwich
RcgnauU
GriLger
Vaux
In Prussia, Austria, and many other parts of the continent, lignite forms a very
zz2
706 LIME.
important prodnct, 1>eing largely employed for domestic and for mann&ctnriDg
purposes. In this country, with the single exception of the Bovey Heathfield formation,
which is used in the adjoining pottery, lignite is not employed.
LIGNUM*yiT^, or Guaiacum (^Guaiaeum officinale and G. »anctmm), a Tery
hard and heavy wood. The fibrous structure of this wood is very remaikable ; the
fibres cross each other sometimes as obliquely as at an angle of 30 degrees with the
axis, as if one group of the annual layers wound to the right the next to the left and
so on, with any exactitude. The wood can hardly be split, it is therefore divided by
the saw'. Lignum-vitn is much used in machinery for rollers, presses, mills, &c^ and
for pestles and mortars, sheers for ship's blocks, skittle balk, and a great variety of
other works requiring hardness and strength.
The gum guaiacum of the apothecary is extracted from this wood.
LILAC DYE. See Calico-prinitno, Dteino, and Anilinb.
LIME. Quicklime^ an Oxide of Calcium, This useful substance is prepared by ex-
posing the native carbonate of lime to heat, by which the carbonic add is ex-
pelled.
This operation is performed in a manner more or less perfect, by burning ealcareons
stones in kilns or furnaces.
Limestone used to be calcined in a very rude kiln, formed by inclosing a eireular
space of 10 or 15 feet diameter, by rude stone walls 4 or 5 feet high, and filling
the cylindrical cavity with alternate layers of turf or coal and limestone brokea
into moderate pieces. A bed of brushwood was usually placed at the bottom, to
fiicilitate the kindling of the kiln. Whenever the combustion was fairly commenced,
the top, piled into a conical form, was covered in with sods, to render the calci-
nation slow and regular. This method being found relatively inconvenient and
ineffectual, was succeeded by a permanent kiln built of stones or brickwork, in the
shape of a truncated cone with the narrow end undermost, and closed at botton by
an iron grate. Into this kiln, the fuel and limestone were introduced at the top in
alternate layers, beginning of course with the former ; and the charge was either
allowed to bum out, when the layer was altogether removed at a door near the bottom,
or the kiln was successively fed with fresh materials, in alternate beds, as the former
supply sunk down by the calcination, while the thoroughly burnt lime at the bottom
was successively raked out by a side door immediately above the grate. The interior
of the lime kiln has been changed of late years from the conical to the ellipdcal form,
and probably the best is that of an egg placed with its narrow end undermost, and
truncated both above and below ; the ground plot or bottom of the kiln being com-
pressed so as to give an elliptical section, with an eye or draft-hole towards each end
of that ellipse. A kiln thus arched in above gives a reverberatory heat to the upper
materials, and also favours their falling freely down in proportion as the finished
lime is raked out below ; advantages which the conical form does not afibrd. The
size of the draft-holes for extracting the quicklime, should be proportionate to the siae
of the kiln, in order to admit a sufficient current of air to ascend with the smoke and
flame, which is found to facilitate the extrication of the carbonic acid. The kilas are
called perpetual^ because the operation is carried on continuously as long as the build-
ing lasts \ and draw-kilntt from the mode of discharging them by raking ont the lime
into carts placed against the draft-holes. Three bushels of calcined limestone, or
lime-shells, are produced on an average for every bushel of coals consumed. Such
kilns should be built up against the face of a cliff, so that easy access may be gained
to the mouth for charging, by making a sloping cart road to the top of the bank.
Figs. 11 34, 1 1 85, U 36, 1 1 37 represent the time-kUn of Riidersdorf near Berlin, npon the
continuous plan, excellently constructed for economising fneU It is triple, and yiekis a
threefold product Fig. 1 136 is a view of it as seen from above ; Jig, 1 137, the eJevatioo
and ^nenil appearance of one side ; Jig. 1 134, a vertical section, and^. 11 35, the grosod
plan m the line A b c d of ^^. 1 134. The inner shaft^S^. 1 135, has the form of two trvii-
cated cones, with their larger circular ends applied to each other ; it has the greatest
width at the level of the fire-door 6, where it is 8 feet in diameter ; it is narrower below,
at the discharge door, and at the top orifice, where it is about 6 feet in diameter. The
interior wall a, of the upper shaft is built with hewn stones to the height of 58 feet,
and below that for 25 feet, with fire-bricks cf' <f , laid stepwise. This inner wall is
surrounded with a mantle e, of limestone, but between the two there is a small vacant
space of a few inches filled with ashes, in order to allow of the expansion of the interior
with heat taking place without shattering the mass of the building.
The fire-grate, b, consists of fire-tiles, which at the middle, where the single pieces
press together, lie upon an arched support/ The fire-door is also arched, and is secoi^
by fire-tiles, g is the iron door in front of that orifice. The tiles which form the grate
have 3 or 4 slits of an inch wide for admitting the air, which enters through the canal k.
pit i, tbe diacliM^ge outlet a, and the canal k, in front of tlie outlet. Each aih-pit ii
ahat with an iron door, which ii opened onlf when the (pace i becomes filled with
Bifaea. These indeed are allowed to remain tUl the; get cool enough to be removed
The discharge oalleu are alto fhrniihed with iron doora, which are opened onljfor
tahing out the lime, sod are carefiilly Inted with loam during tbe burning. The outer
valli I n n of the kiln, are not osentiall; necesuiy, but convenien% becauae the; afford
room for the lime to lie in tbe lower floor, and tbe Fuel in the second. The several
■toriee are formed of groined arches o. and platforma p, covered over with limestone
slsha. In thelhird aadfourth itoriea the workmen lodge at night Seefig I13T. Some
enter their apartments bj the npper door g ; oihen b; tbe lower door i. r ia one of
the ohimnej^ for the several flreplaees of the workmen, (i a, « are sturs.
As the hmestoue is introduced at top, the month of the kilu is sorrouuded with a
strong iron balustrade Co prevent the danger of the people tambling in. The platform
is laid with rsili w. fbr the waggons of limestone, drawn bji horsea. to mu upou. z i*
another railway, leading to another kilo. Such kilua are named atter the number of
their fire-doors, single, twofold, threefold, fourfold, &e. ; from three to five being the
moat usual. The outer form of the kilo also ia determined bj the number of the
faraaces; beingatrancatedpyramidof eqnalsides ; and in the middle of each alternate
side there is a fireplace, and a discharge outlet A cubic foot of limeslone requires for
hnming, one and five-twelfths of a cubic foot of wood, and one and a half of turf.
When the kiln is to be set in action, it is filled with rough limeslones, to the height
C D, or to (he level of the firing; a wood fire is kindled in a, and kept up till the lime
i« calcined. Upon this masa of qnicWime, a fresh qnantity of limestones is introduced,
cot thrown in at tbe month, but let down in buckets, till the kiln is qnile fiiU ; while
over the Cop a cone of limestones ia piled up, about 4 feet high. A turf-fire is now
kindled in the fiimaccs b. Whenever the upper stones are well calcined, tbe lime
cx3
710 LIMESTONE,
onder the fire-lerel is taken ont, the superior column falls in, a new cone it piled np,
and the process goes on thus vrithoot interruption, and without the necessity of ooce
putting a fire into a ; for in the space c b, the lime must be always well calcined. Tbe
discharge of lime takes place eyery 12 hours, and it amounts at each time in s thre^
fold kiln, to from 20 to 24 Prussian tonnes of 6 imperial bushels each ; or to 130 batheli
imperial upon the ayerage. It is found bj experience that fresh*brokeD limestoiK,
which contains a little moisture, calcines more readily than what has been dried by
exposure for some time to the air ; in consequence of the raponr of water promothig
the escape of the carbonic acid gas ; a fact well exemplified in distilling essential oils,
as oil of turpentine and naphtha, which come over with the steam of water at npvards
of 100<^ Fahr. below their natural term of ebollition. Six bushels of Riidersdorf
quicklime weigh from 280 to 306 pounds.
Anhydrous lime, or, as it is commonly called "quicklime^ is sn amorphoos solid,
Taryiog much in coherence, according to the kind of rock from which it is obtained;
its specific grarity raries from 2*3 to 3. Lime is one of the most infosible bodies
which we possess ; it resists the highest heats of oar furnaces.
When exposed to air, quicklime rapidly absorbs water and crumbles into a powder,
commonly known as slaked lime, which is a hydrate of lime.
Hydrate of lime when exposed to the air absorbs carbonic acid, and after long ex-
posure it is converted into a mixture of carbonate of lime aod hydrate of lime in single
equivalents. Hydrate of lime is but slightly soluble in water, 729 to 733 parts of that
fluid dissolving only 1 part of the lime at ordinary temperatures.
Hydrate of lime is applied to numerous purposes in the arts and mannfactnra. It
is chiefiy employed in tbe preparation of mortar for bailding purposes. See Moktib.
The pure limes, prepared from the carbonates of lime, form an imperfect mortar
suitable only for dry situations. In damp buildings or in wet situations thej nerer
set (as the process of hardening is technioally termed), but always remain in a polpj
state. General Pasley says, ** The unfitness of pure lime for the purposes of hydraolie
architecture has been proved by seyeral striking circumstances that have come nsder
my personal observation, of which I shall only mention a few. First, a great ponioo
of the boundary wall of Rochester Castle having been completely undermined, nearly
throughout its whole thickness, which was considerable, whilst the upper part of the
same wall was left standing, I had always ascribed this remarkable breach tovidence,
considering it as having been the act of persons intending to destroy the wall for tlie
sake of the stone ; but on examining it more accurately after I had began to study
the subject of limes and cements, I observed that the whole of the breached part was
washed by the Medway at high water, and that all the mortar of a small portion of
the back part of the foot of the wall still left standing was quite soft, bat that tovards
the ordinary high water level it became a little harder, and above that level it ^^
perfectly sound. I obserred the same process at the outer wall of Cockham Wood
Fort, on the left bank of the Medway below Chatham, of which the upper part i^
standing, whilst the lower part of it'had been gradually ruined by the action of tbe
river at high water destroying the mortar."
Obervations on limes, calcareous cements, JYr. — The peculiar conditions necessary to
insure a good and useful mortar for building purposes, and, the peculiarities of the
hydraulic mortars or cements, will be treated of under Mortab, which see.
LIMESTONE. ( Calcaire, Fr ; Kalkstein, Germ.) A great variety of rocks contain
a sufficient quantity of lime in combination to be called limestones.
Chalk is an earthy massive opaque variety, usually soft and without lustre, and may
be regarded as a tolerably pure carbonate of lime. Carbonate of lime dissolves in 1000
parts of water charged with carbonic acid. (Bischof.) Fresenius states that it dissoltes
m 8834 parts of boiling water and in 10,601 parts of water at ordinary temperatnwi.
Carbonate of lime is found in nature more or less pure, both crystallised perfteUfi
as in calcspar and aragonite imperfectly ; as in granular limestone ; and in compact
masses, as in common limestone, chalk, &c. ^
Stalactitic carbonate of lime, frequently called concretionary limestone, is formed by
the infiltration of water through rocks containing lime, which is dissolved ont, and«
it slowly percolates the rocks into cavernous openings, the water parts with its carbo-
nate of lime, which is deposited in zones more or less undulated, which have a fibrous
structure from the crystalline character of the concretionary lime. The loogfibnw*
pieces called stalactites show those fibres very beautifully. The stratiform m>^
called stalagmites exhibit a similar structure, varied only by the conditions nnder
which they are formed. A very remarkable stalagmitic limestone found in Egyp^ ^
known as oriental alabaster.
True Alabaster is a sulphate of lime (see Alabaster), but the stalagmitic carbonate
is not unfrequently called by this name.
Incrusting concretionary limestones differ but little from thcAbove. They are deposits
LIMESTONE. 711
from calcareous springs whicli are common in some parts of Derbyshire, Yorkshire,
and other places. It is a common practice to place Tegetable substances in those
springs ; they then become incrusted with carbonate of lime, and are sold as petrifac-
tions, which they are not In Tolcanic districts many rery remarkable springs of
this character exist One of the most remarkable is at the baths of Sao Filippo
in Tnscany, where the water 6ows in almost a boiling state ; carbonate of lime here
appears to be held in solution by salphuretted hydrogen, which files off when the
water issues to day* Br. Vegny has taken advantage of this property of the spring
to obtain basso-relicTo figures of great whiteness and solidity by occasioning the lime
to deposit in sulphur moulds.
Agaric mmeral^ Spongy limwione^ Bock milk, is fonnd at the bottom of and about
lakes whose waters are impregnated with lime. The ealcartout tufa of Derbydiire
is of this character ; it may be studied in every stage of formation.
TVnwr^uM, which served to construct most of the monuments in ancient Rome, ap-
pears to have been formed by the deposits of the Anio and the Solfatara of Tivoli.
The temples of PsBstum, which are of extreme antiquity, have been built with a travtr-
tmo^ formed by the waters which still flow in this territory.
Compact limetUmc has a compact texture, usually an even surface of fracture, and
dull shades of colour.
Granular UtmettoM includes common statuary and architectural marble, and has a
texture something like loaf-sugar. (See Marble.) Under those two heads are
grouped a great number of varieties.
OoUte or roe atone consists of spherical grains of yarious sixes, from a millet seed
to a pea or even an egg.
Coarte grained limestone. Coarse lias has been referred to this head.
Marlg limestone, lake and fresh-water limestone formation, texture fine grained,
more or less dense ; apt to crumble down in the air ; colour white or pale yellow ;
fracture rough grained, somewhat conchoidal ; somewhat tenacious. Texture occa-
sionally cavernous, with cylindrical winding cavities. This true limestone must not
be confounded with lime marl, which is composed of calcareous matter and clay.
Siliceous limestone, A combination of silica and carbonate of lime, varying very much
in the proportions and sometimes passing from ckerty limestone into chert It scratches
steel, and leaves a siliceous residuum after the action of muriatic acid.
Stinkstone or SwinesUme. A carbonate of lime combined with sulphur and organic
matter. It emits the smell of sulphuretted hydrogen by a blow or by friction. It
occurs at Assynt, in Sutherlandshire, in Derbyshire, and some parts of Ireland.
Bituminous limestone. Limestone containing- various hydrocarbon compounds, dif-
fusing by the action of fire a bituminous odour, and becoming white when burnt
Limestones of whatsoever kind may be referred to defwsition effected by chemical
change. The immense lapse of time required to form ihe great limestone ranges of
this country can scarcely be estimated. Professor Phillips has the following remarks
on this : —
** It is certain that while the sandstones, shales, coals, and thin oolitic limestones of
the North York moors were deposited upon the lias, a deposit almost wholly calcare-
ous was occasioned near Bath. The whole time consumed was the same in each
locality. We may, therefore, perhaps infer the comparative rate of deposition of the
oolite and the sandstones. The total thickness of the mass in Yorkshire is about
750 feet, of which about 20 may be called limestone; of that near Bath 480, of
which nearly half is sand and clay with calcareous matter interspersed. Hence we
have the proportion of three feet of sandstone deposited in the same time as one of
limestcme. Another instance is afforded by comparing the sections of the lower
carboniferous limestone in Derbyshire and in Tjmedale. In the former tract we may
Uke 750 l^t as die thickness of limestone, wiUi no admixture of sands or clays ; in
the latter ; the contemporaneous strata are at least 1,750 feet thick, and contain 367 feet
of limestone, and 1,283 feet of sands and clays, &c ; consequently, 383 of limestone
correspond in time to 1,283 of sand, clays, and coal, or 1 to 3 3.**
The fbrmation of limestone under different circumstances is an interesting study.
Some of our great limestone formations indicate a marine, while others very clearly
show a fresh water origin. Mr. Jukes, in his StudenCs Manual of Geology, says :
** The marine depositions cf carbonate of lime now taking place are best studied^ in
coral reefs. In almost all tropical seas incrusting patches or small banks of living
coral are to be found along the shores, wherever they consist of hard rock and the
water is quite clear. In the Indian and Pacific Oceans, however, far away from any
land, huge masses of coral rock rise up from vast and unknown depths, just to the
level of low water. These masses are often unbroken for many miles in length and
breadth ; and groups of such masses, separated by small intervals, occur over spaces
sometimes 400 or 500 miles long by 50 or 60 in width. The barrier reef along the
K Z 4
712 LIME TREE.
north-east coait of Australia is composed of a chiun of soch masses, and is more tliao
1000 miles long, from 10 to 90 miles in width, and rises at its seaward edge from
depths whieh in some places certainly exceed 1800 feet These reef masses consist
of liTing corals only at their upper and outer surface, all the interior is composed of
dead corab and shells, either whole or in fragments, and the calcareous portions of
other marine animals. The interstices of the mass are filled up and compacted toge>
ther by calcareous sand and mnd, derived from the waste and debris, the wear ud
tear of the corals and shells, and by countless myriads of minute organisms, mostly
calcareous also. The surface of a reef when exposed at low water is composed of
solid looking stone, which is often capable of being split up and lifted in slaba, bearing
no small resemblance to some of our oldest limestones. . • • . Guided by these
facts and observations we may form tolerably accurate notions of the mode of origin
of. all our marine limestones, and attribute to them an organic-chemical origin,
taking into account, at the same time, how easily they may have been subsequently
alter^ in texture by the metamorphic action either of water or heat" Dr. Lyoo
Playfair suggests two additional modes by which a chemical precipitation of carbonate
of lime might in some places be formed on the bottom of the seas. He says most rirers
contain small quantities of silicate of potash ; and when this is carried into the sea, some
of the carbonic acid contained therein may unite with the potash, thus rendering pos-
sible a precipitation of carbonate of lime in a solid form, and also of silica. Marine
▼egetables also, like terrestrial regetation, require carbonic acid, and, by extnettng
it from sea water, may reduce the amount in particular localities below that which is
necessary to keep all the carbonate of lime in a fluid state, and thus render a solid
precipitation of that substance possible. — Z>e la Beche.
" Limestones," says Mr. Jukes, " may be hard or soft, compact, concretionary, or
crystalline, consisting of pure carbonate of lime or containing silica, alumina, iron,
&C., either as mechanical admixtures or as chemical deposits along with it Different
Tariedes of limestone occur in different localities, both geographical and geological,
peculiar forms of it being often confined to particular geological formations over wide
areas, so that it is much more frequently possible to say what geological formation a
specimen was derived firom, by the examination of its lithological characters, io the
case of limestone than in that of any other rock. Compact limegttme is a hard smooth
fine-grained rock, aenerally bluish-grey, but sometimes yellow, black, red, white or
mottled. It has either a dull earthy fracture or a sharp splintery and conchoidal one.
It will frequenUy take a polish, and when the colour is a pleasing one is ased as an
ornamental marble. CryaiaUine limestone may be either coarse or fine-grained, vary-
ing from a rough granular rock of various colours to a pure white fine-grained one,
resembling loaf-sugar in texture. This latter variety is sometimes called sarcAonuuv
sometimes statuary marble,**
Oolitic limestone includes Bath stone, Portland stone, and Caen stone.
Pisolite is a variety of oolite, in which the concretions become as large as peas.
Nummylitic limestone, Ctymenia^ Crinoidal limestones are so called from the fossils
which the rock contains.
Shell limesione or muxhelkalk has its name in the same way from its eompoatioo.
Cipclino is a granular limestone containing mica.
Majolica^ a white and compact limestone.
Scaglia, a red limestone in the Alps. For the three last see Marblb.
Limestone, Magnesian, see Dolomite <Z>o/oni/e, Fr. ; Bitierkalk^ Talkspatk^
Germ.), is a mineral which crystallises in the rhombohedral system. Spec. grav. 2 86;
scratches calc-spar ; does not fall spontaneously into powder when calcined, as com-
mon limestone does. It consists of 1 prime equivalent of carbonate of lime » 50,
associated with 1 of carbonate of magp[iesia=42.
Massive magnesian limestone^ is yellowish-brown, cream-yellow, and yellowish-grey;
britde. It dissolves slowly and vrith feeble effervescence in dilute muriatic acid ;
whence it is called Calcaire lent dolomie, by the French mineralogists. Specific gravity
2-6 to 27.
Near Sunderland, it is found in flexible slabs. The principal range of hills com-
posing this geological formation in England, extends from Sunderland on the north-
east coast to Nottingham, and its beds are described as being about 300 feet thick oa
the east of the coal field in Derbyshire, which is near its southern extremity. — H.W. R
LIME TREE ( Tilia Europea), The well-known linden tree, common toall Europe.
The wood is very light-coloured, fine and close in the grain, and when properly
seasoned, not liable to warp. It is much used in the manidlEusture of piano fortes and
harps. It is made into cutting boards for curriers, shoemakers, &C., as it does not
turn the knife in any direction of the grain, nor injure the edge.
Lime tree wood is especially useful for carving, f^m its even texture and fireed<H&
LINEN. 713
from knoti. The beaotiful works of Gibbons at Hampton Goort» at Windsor, and at
Chatswortb, are executed in lime tree wood.
The no less beautiful works of our celebrated liring wood carver, Rogers, are
executed in this wood.
LIMOGE WARE. See Pottery.
LIMONITE. A namefor several varieties of iron ore, such as the brown hiema*
tite and bog iron ore. There is much difficulty in distinguishing the various
kinds of iron ore, they shade so gradually one into the other ; but it is clearly a very
unscientific mode of proceeding to group things unlike each other under a common
name.
LINSEYS, sometimes called linsey-woolsey ; being a combination of flax and wool,
which are woven into coarse cloth, usually employed to clothe those who are entirely
dependent on public charity.
LINEN. See Flax, and Textile Fabrics.
Linen distinguished from cotton. Cotton may be distinguished from linen or flax by
immersing the former, well washed and dried, for about a minifte in strong sulphuric
acid. It is then to be wit&drawn and washed with water containing a little alkalL
The cotton will dissolve as a gummy mass, while the linen- will retain its thready
texture.
The manufacture of linens is carried on extensively in the north of Ireland, and on
the continent in Bohemia, Moravia, Silesia, and Galicia. Of the entire production,
independent of the Irish linen, about five- twelfths are brought into the market, and of
this quantity the bulk must be of domestic manufacture, smce few great linen manu-
ikctories exist in Austria. Within the Austrian dominions, among the linen fabrics,
table-cloths and napkins, veils, cambrics, dimities, twills, and driUs are important
articles. In the next rank we must place the manufacture of thread, especially in
Bohemia, Moravia, and Lombardy. The tape manufacture is of less consequence ;
and as to the business of dyeing and printing, that has been almost entirely absorbed
by the cotton manufacture, and is now in requisition for thread and handkerchief^
only.
As the loss resulting from the processes of weaving, bleaching, &c is estimated at about
10 percent. Uie net aggregate of these manuftetures of linen, thread, &c., may be assumed
at,say, 1,037,000 cwt ; of which quantity about 450,000 cwt come into the market, the
rest being absorbed by domestic consumption. Since, upon an average of the five years from
1843 to 1847, there appear to have been imported fix>m abroad only 242 cwt whereas the
average of exports for the same period shows 42,609 cwt, it follows that there remamed
for home consumption about 1,000,000 cwt Thus, on a population of 88,000,000 of
persons, about 2] lbs. would fall to the share of each ; but this estimate falls much below
the truUi, when we consider that the national costume in Hungary and Galicia requires
more than double the quantity we have allowed for. In fact the crop of flax is esti-
mated to be 10 per cent higher than is given in the official reports ; but the consump-
tion of even 3 lbs. per head, which would thus result, is yet smaller than in reality it
must be. In the imperial army of Austria the quantity used up annually by each man
averages more than 7 lbs.
In ihe above statistics of the manufacture of linen goods no allowance has been made
fbr the extensive production of rope work and the like.
From the article Flax, reference has been made to this article for available in-
formation in the statistics of the production of the raw material and of the finished
article in this country. The following ample tables will ftilly set forth the value
of this important manufacture.
• After the information already conveyed to the reader in the article Flax, what
has been said with regard to Cotton Manufacture, and the additional matter in the
article Textile Fabrics, it does not appear necessary to say anything more on the
subject of linen manufiuture.
Flax dressed : —
Fron
Russia
Prussia
Holland
Belgium
Egypt
Other parts
Imports of Flax in 1857.
Cwtf.
£
40 -
-
112
36 -
-
101
2,374 '
-
6,635
26 -
-
72
839 -
-
1,791
560 -
-
1,541
3,875 £10,252
714 LINEN.
Tow and codiUa of flax : —
From Cwts. £
Rassia - - - - 193,195 - - 284,996
Prussia - - - - 10,359 - - 15,110
HanoTer - - - - 4,682 - - 6,685
Hanse Towns - - - 6,715 - - 9,448
Holland ... - 23,786 - - 33,324
Belginm - - - - 1,386 - - 1,888
Other parts . - - 1,910 - - 2,637
241,986 £354,088
Bongb and nndressed : —
From CwU. t
Russia ... - 1,081,657 - - 1,924,707
Prussia - - - - 263,177 - - 475,154
Holland .... 120,374 • - 320,928
Belgium ... - 120,913 - - 353,599
France - - - - 24,253 - - 70,597
Egypt - - - - 6,099 - - 7,463
Other parts - - - 3,916 - - 7,979
1.620,389 £3,160,427
Imports of Linen in 1857.
Linen yam : —
From Cwts. Computed real Viloe.
Russia ... - 2,487 - - £l7,13l
Other parts ... 43 - - 291
2,530 £17,422
Linen manufactures : —
Cambric handkerchiefs, hemmed or hemstitched, not trimmed : —
From Nambcr. Computed real Value.
France .... 36,379 - - £5,002
Other parts ... 131 • - 18
36,510 £5,020
Cambrics and lawns, commonly called French lawns, plain : —
From Square Yards. Computed real Value.
Belgium .... 260 - - £650
France - - • - 18,718 - . 4,679
21,318 £5,329
Bordered handkerchief : —
From Square Yards. Computed real Valoe.
Belgium .... 8,508 - - £1,382
France .... 115,871 - - 18,829
Other parts ... 700 - - 114
125,079 £20,325
Entered at Value.
Lawns not French : —
From £
Egypt 147
China - - - - 623
Other parts .--.-...87
£857
Damask and damask diaper : —
From Square Yards. £
Hanse Towns ... 12,185 - - 1,823
Holland .... 1,953 . . 226
France .... 3,025 • - 227
17,168 £2,276
LINEN.
715
Entered at Valae.
Sails:—
From
Bossia
Norway -
Hanse Towds -
Holland -
Belginm -
it
564
312
241
1,669
889
From
United States
ADStralia -
Other parts
Plain linen and diaper unenumerated : —
From *
Hanse Towns -
Holland -
Belgium -
58
35
150
From
Other parts
Not separately specified, wholly or partially made up:—
From ^
Russia - - - 891
Hanse Towns - - 2,031
Holland - - - 1»381
Belgium - - - 385
France . - - 6,882,
From
British East Indies
Other parts
Ditto, not made up : —
From
Russia
Hanse Towns -
Holland -
Belgium -
France
Turkey. Proper -
4t
19,297
5,832
1,548
9,864
1,536
720
From
United States
Malta
Australia -
Other parts
Exports of LineJh ffc. in 1857.
Linen yam : —
To
Russia, northern ports
Denmark -
Prussia
Hanover
Hanse Towns
Holland
Belgium
France
Spain and Canaries
Sardinia
Tuscany -
Two Sicilies
Austrian territories
Turkey
United States
Gibraltar -
Other countries -
Lbi.
83,047
303,394
318,239
1,296*836
9,142,759
4,405,029
2,072,562
528,980
7,493,534
933,151
535,071
298,817
73,438
133,866
69,867
1,042,134
178,239
Linen manufactures : —
White and plain : —
To
Rossia, northern ports
Norway
Denmark -
Prussia
Hanorer
Hanse Towns
Holland
Belgium
France
Portugal, &c.
28,908,963
Yardf.
310,013
1 17,326
582,910
125,595
144,957
5,354.685
744,525
188,864
1,105,156
1,344,823
1,180
860
944
£5 559
21
£264
193
292
£11,557
581
945
2,358
1,667
£44,348
Vahie.
£6,578
13,686
23,043
86,306
522,246
250,784
117,268
88,507
389,474
40,638
24,538
18,794
4,013
5,822
2,454
45,363
12,250
£1,651,714
16,339
5,612
16,873
6,086
7,928
182,897
24,030
7,872
70,910
32,453
16
LINEN.
White and plain (eontinued) —
To
YardL
Spain, &c -
-
-
1,677,439
Sardinia
-
-
740,085
Tuscany - '
-
.
744.693
Papal States
-
•
218,354
Two Sicilies
•
-
773,085
Austrian territories
•
-
431,916
Turkey
m
-
400,632
Egypt
-
.
189,655
Philippine blands
-
.
407,098
China
-
.
519,128
South Sea Islands
■
-
673,101
Cuba ...
.
-
10,829,176
Porto Rico -
*
-
313,437
St. Thomas
•
.
6,018,485
Haiti -
.
-
2,688,357
United States -
m
m
42,943,492
Mexico
.
.
1,815,399
Central America -
.
-
245,602
New Grenada
•
.
1,796,596
Venezuela -
-
•
3,653,563
BrazU
m
-
11,540.439
Uruguay .
-
-
416,055
Buenos Ayres
.
.
963,332
ChUi ...
.
-
2.755,475
Peru ...
-
-
2,254,011
Channel Islands •
*
•
245,980
Gibraltar -
-
.
585,730
Malta
-
-
306,684
British possessions
in South
Africa .
.
825,726
Mauritius -
-
112,976
British East Indies
•
1,332,502
Hong Kong
-
140,874
Australia -
.
3,296,744
British North America
2,256,505
British West Indian islands, &c
4,818,537
Honduras British settlements
184,984
Other countries -
■
1
709,274
19,847,975
Checked or striped : —
To
Yards.
United States
.
.
76,069
British possessions
in Soath
Africa .
•
.
20,652
British West Indies, &c
.
47,400
Other countries -
35,154
179,275
Printed, stained, or dyed : -
—
To
Yardf.
Hanse Towns
•
77,907
France
-
22,412
Cuba ...
.
1,930,204
Porto Rico -
.
211,548
St Thomas
.
483.046
United States
-
1,957.645
New Grenada
•
115,670
Brazil
«
337,989
Australia -
m
61,712
British North America
m
230,118
British West Indian Isles
m
452,946
Other countries -
-
-
246,011
<
80,052
31,693
28,598
8,964
86,128
17,189
15,197
7.249
10,798
8,656
11.138
375,583
7,390
147,164
70,774
- 1,290,890
68.764
7,130
42,971
80,046
299,340
10.758
29,965
75,584
72,638
12.924
23,964
10,770
26,241
3.675
53,063
4,567
105,939
66,408
105,759
4,532
20,390
- de3,643,785
6,127,208
£
1,853
2,904
70,011
4,300
8,480
55,111
3,014
15,353
1,500
5,793
8,870
7,030
£184,619
LINEN.
717
Cambric and lawn : — -
To
Yurdt.
£
Java - - -
-
15,000
-
1,691
Cuba - - -
-
84,184
.
4,085
United States
-
1,183,768
.
51,110
New Grenada
-
91,596
-
2,446
Brazil
-
34,190
-
2,266
Buenos Ayres
-
7,235
.
1,306
British East Indies
" *
17,215
.
913
Australia -
.
44,583
•
2,718
British West Indies
.
20,238
-
766
■ Other countries -
*
84,124
1,582,128
"
5,381
£72,682
Damask and diaper : —
To
Yards.
£
Hanse Towns
m m
51,966
-
3,301
United States -
» m
454,613
•
24,005
Australia -
.
31,113
.
2,184
British North America
10,970
-
581
Other countries -
m m
54,427
603,089
Yard*.
4,757
^£34,828
£
Sail doth, total exports
5,442,327
•
234,845
Sails ditto
«» ^
-
-
7,667
Ticking ditto
-
57,596
-
1,630
lace of thread : —
To
Yards.
£
United States
.
23,365
-
971
Brazil
. .
6,000
.
124
Channel Islands -
.
18,000
.
450
Other countries -
a •
25,532
72,897
^
747
£2,292
Hosierj, tapes, and small wares : —
To
£
Hanse Towns -
.
•
.
844
United States -
.
.
.
1,390
Peru
-
.
.
1,374
Other countries
4,421
£8,029
Thread for sewing :«-
To
Lbs.
- £
Russia, northern portc
1 -
23,37!
•
2,180
Norway
m m
61,383
-
4,275
Denmark -
-
24,753
.
2,575
HanoTer
. •
88,116
.
10,438
Uanse Towns
. .
864,220
.
94,332
Holland -
• .
35,674
m
3,258
Belgium
.
31,300
-
3,405
Austrian territories
.
85,084
-
3,024
Turkey
m m
27,271
.
1,847
Cuba ...
-
57,820
.
4,736
St. Thomas -
-
23,925
m
1,859
United States
-
1,666,089
.
155,831
Brazil
-
67,143
••
4,314
Buenos Ayres
-
29,523
-
1,563
Gibraltar -
-
17,718
.
1,633
British possessions in
& Africa
27,222
.
2,359
British E^nst Indies
-
30,076
.
2,483
British North America
113,378
.
9,344
Other countries -
. .
137,932
-
12,682
3,361,498
£322,318
718 LINSEED OIL.
Unennmerated : —
To
£
To
£
Hanse Towos -
IS6
British East Indies
- 361
France
160
British West Indies
- 668
New Grenada -
480
Other coimtriet -
- 528
Brazil -
. 1,318
Gibraltar -
120
je3,771
LINSEED. {Grainede lin^ Fr.; Leituamet Germ.) The seed of the flax, Lmmm
Utitatissimum, which is indigenous to our islands, and is cnltiyated extensively in this
and other countries for its seed, and tor flax. Linseed contains in its dry state, 1 1 265
of oil ; 0 146 of wax ; 2*4808 of a soft resin ; 0*550 of a colouring resinous matter ;
0*926 of a yellowish substance analogous to tannin ; 6 154 of gum ; 15*12 of Tegetable
mucilage; 1*48 of starch ; 2*982 of gluten ; 2*782 of albumine; 10 884 of saccharine
extractive ; 44*882 of enyelopes, including some vegetable mucilage. It contains also
free acetic acid ; some acetate, sulphate, and muriate of potash, phosphate and sulphate
of lime : phosphate of magnesia ; and silica.
LINSEED OIL is obtained fh>m linseed by first bruising the seeds, grinding them,
and subjecting them to violent pressure, either by means of wedges, or of the hydraulic
or screw press. Cold drawn linseed oil is obtained cold, and is paler eoloured, less
odorous, and has less taste than that which is obtained when heat is applied.
It is usual to employ a steam heat of about 200*^ Fahr. By cold expression the seeds
yield al)out 20 per cent, while b^ the aid of heat nearly 27 per cent of oil can be
obtained. The ultimate composition of linseed oil is carbon 76*014, hydrogen 1 1*351,
and oxygen 12*635 ; its proximate constituents being oleic and margaric acids, and
glycerine. Linseed oil is much used as a vehicle for colours by the painter. If
linseed oil is exposed in a thin coat to the air it absorbs oxygen and becomes tenacious,
and in many respects like caoutchouc : upon this property mainly depends its use in
the arts. To secure this more readily a drying process is adopted, which most be
described.
When linseed oil is carefully agitated with acetate of lead (tribasic acetate of lead),
and the mixture allowed to clear by settling, a copious white cloudy precipitate forma,
containing oxide of lead, whilst the raw oil is converted into a drying oil of a pale
straw colour, forming an excellent varnish, which, when applied in thin layers, dries
perfectly in twenty-four hours. It contains ftx)m four to five per cent, of oxide of
lead in solution. The following proportions appear to be the most advantageous for
its preparation.
In a bottle containing A\ pints of rain water, 18 ounces of neutral acetate of lead are
placed, and when the solution is complete, 18 ounces of litharge in a very fine powder
are added ; the whole is then allowed to stand in a moderately warm place, frequently
agitating it to assist the solution of the litharge. This solution may be considered as com-
plete when no more small scales are apparent The deposit or a shining white colour
(sexbasic acetate of lead) may be separated by filtration. This conversion of the
neutral acetate of lead into vinegar of lead, by means of litharge and water, is effected
in about a quarter of an hour, if the mixture be heated to ebullition. When heat is
not applied, the process will usually take three or four days. The solution of vinegar of
lead, or tribasic acetate of lead, thus formed, is sutficient for the preparation of 22 lbs.
of drying oiL For this purpose, the solution is diluted with an equal volume of rain
water, and to it is gradually added, with constant agitation, 22 lbs. of oil, with which
18 ounces of litharge have previously been mixed.
When the points of contact between the lead solution and the oil have been fre-
quently renewed by agitation of the mixture three or four times a day, and the mixture
allowed to settle in a warm place, the limpid straw-coloured oil rises to the surface,
leaving a copious whitish deposit. The watery solution rendered clear by filtration,
contains intact all the acetate of lead first employed, and may be used in the next
operation, after the addition to it as before of 18 ounces of litharge.
By filtration through paper or cotton the oil may be obtained as limpid as water,
and by exposure to the light of the sun it may also be bleached.
Should a drying oil be required absolutely free from lead, it may be obtained by
the addition of dilute sulphuric acid to the abo^e, when, on being sillowed to stand,
a deposit of sulphate of lead will take place, and the clear oil may be obtained free
from all trace of lead.
Linseed oil was at one time much used in the preparation of a liniment, which, as
it is one of the very best possible applications to a burnt surface, cannot be too
generally known. If equal part* ofUmewater and Unseed oil are agitated together,
they form a thick liniment, which may be applied to the bum with a brush or
feather. It relieves at once from pain, and forming a pellicle, protects the abraded
parts from the air. The linimentum calcis of the Pharmacopoeia is equal parts of
LIQUATION. 719
■ thk it & more elegant but » leu eSective preparstioD.
which coDsisN in the emplcijiiieDt of pccolierl; coDitmcted scrapen fi>T abndiag tlie
Mrface of (he linen cloth, and producing & pile or nap apoD iL The unpen are
worked bj a roiary motion.
Inilead of rotary icnpen, a reciprocating pendnlonl moTemeul i> sometimea applied
to a HDgle Bcraper. Cbisel-fonued blodei are claimed by the patentee ai icrapen for
railing the pile, by working with the bcTel edgei forwards, bo ai to icnpe and not to
cot ihe fabrio. He baa io the rotary form a ledge or bed concentric vilb the aiit of
the acnper, which he also claims j both of which leem to be lerviceable. Several
kiodi of liDt-making machinet are now emploi^ed, bat a* they all partake more or lea
the abo»e princijJea they do not require deicnption.
LIQUATION (Eag. and Fr.; Saigtnmg, Qtrm.) it the procea* of aweating out,
by a regulated beat, fixim an alloy, a more eaiily fuaible metal, from the interstices of a
metal, which ii more difficult of fusion. Lead aod antimony are the metals most com-
monly subjeeted to liquation: lead for the purpose of remoTing by its superior affinity
the silier present in any complex alloy; antimony aa an easy meana of aeparatiag it
Figt. 1 138, 1 130, I UO, represent tbe eelebrkled antimonial liquation funuteei of
Malboac, in the department of Ard^che, in 1I3S
France. Fig, 1 1 3B, is a ground plan taken at
the level of the draught botetp^,^. ll3S,«Dd
of tbe dolled line i r ; fiy, 1139, ia a vertical
•eetioa throagb the dotted line A B, of fy.
I13B;aod&. 1140, iaa verticalsection through
the dotted line c D of ^. 1138. In the three
figures, the same letten denote like otgecta. 4 |
o, A, e are three gratri upon the same level above
the floor of the works, 4^ feet long, by lOJ.
inehea bn»d ; between which are two rec-
tangular galleries, d t, which pass transversely
through the whole furnace, and lie at a level
of IS inches above the ground. They are se-
jjanted by two walla hom the three Sre places. Tbe walla have three open-
"V fi 3<^ altematdy placed for the flames to play through. The ends of Uicse
1)39 1140
fpiUeriea are abut in with iron doon i, ■', containing peep holes. In each gallery are
two conical cast-iron crucibles A k, into which the tliqvathg sulphurct of antimony
drops. Their height is ftota IS to 14 inches 1 ibe width of the mouth is 10 inches,
that of the boll'im it 6, and the tlilcknets four-tenths of an ioch. They are coated
over with fire-clay, to prevent the culphurel from acting upon them ; and they eland
upon caat-iroupedeslals with projecting ears, to facilitate tbeir removal fh>m the gallery
or platform. Bothorthese galleries are lined with tiles of fire-clay //, which also serve
aa support* to the vertical liquation tubi« « n, made of the some clay. Tbe tiles are
720 LIQUEURS.
tomewbat carved towards the middle, for the purpose of receiTiiig the lower ends of
these tabes, and have a small hole at n, throagh which the liqaid solpbaret flows down
into tbe cracible.
The liqaation tabes are conical, the internal diameter at top being 10 inches, at bot-
tom 8 i the length fully 40 inches, and the thickness six-tenths of an inch. Thej have
at their lower ends notches or slits, Otfig- 1140, from 3 to 5 inches long, which look oat-
wards, to make them accessible from the front and back part of the furnaces throngh
small conical openings p p, in the walls. These are closed during the operation with
clay stoppers, and are opened only when the gangue, rubbish, and cinders are to be raked
out The liquation tubes pass across the arch of the furnace g 9, the space of the arch
being wider than the tubes ; they are shut in at top with fire-covers r r. « «, the
middle part of the arch, immediately under the middle grate, is barrel-shaped, so that
both arches are abutted together. The flames, after playing round about the sides of
the liqaation tubes, pass off through three openings and flues into the chinmey ^ about
13 feet high ; u, being the one opening, and v, the two others, which are provided
with register plates. In front of the furnace is a smoke flue ir, to carry off the sulphu-
reous vapours exhaled during the clearing out of the rubbish and slag ; another, x,
begins over y y, at the top of the tubes ; a wall r, separates the smoke flue into
halves, so that the workmen upon the one side may not he incommoded by the fumes
of the other. This wall connects at the same time the front flue 10 with tbe chimney
t a' a' and V b' are iron and wooden bearer beams and rods for strengthening the
smoke-flue, c' d are arches upon both sides of the furnace, which become narrower
from without inwards, and are closed with well fitted plates d! <f . They serve in
particular circumstances to allow the interior to be inspected, and to see if either of
the liquation furnaces be out of order. Each tube is charged with 500 lbs. of aoti-
monial ore, previously warmed ; in a short time tbe sulphuret of antimony begins to
flow off. When the liquation ceases, the cinders are raked out by the side openings,
and the tubes are charged afresh. The luted iron crucibles are allowed to become
three-fourths full, are then drawn out from the galleries, left to cool and emptied.
The ingot weighs about 85 pounds. The average duration of the tubes is 3 weeks,
Tnis plan is proved to be an exceedingly economical one.
LIQUEURS, LIQUORISTE. Names given by the French, and adopted into oar
language, to certain aromatic alcoholic cordials, and to tbe manufacturer of them.
Some liqueurs are prepared by infiising the woods, fruits, or flowers, in either water
or alcohol, and adding thereto sugar and colouring matter. Others are distilled from
the flavouring agents.
Many of the liqueurs are of very compoand character, as the following recipes will
show.
Afariinique Noyeau : — Put into a stone jar,
Preserved guavas and their syrup, or the jelly of that fruit - - ^ lb.
Oil of sweet almonds - - - - - - - -loz.
Sweet almonds, beaten fine ..-.-.-i
Bitter „ „ ---.---i
Preserved ginger and its svmp - - • - - - 2
Cinnamon and cloves (bruised) of each ■..---*
Nutmeg and Pimento „ »t ' - ' " ~
Jamaica ginger „ - - - .• - - •_
Candied lemon and citron, of each •---.. 1
White sugar candy (powdered) - - - - - -14
Proof spirit of wine ........5 qturta.
Beat the oil with a little brandy, and mix it with the almonds, when beaten to a
paste with orange flower water. Stop op the jar securely, and let it remain in a warm
room, or in the sun, shaking it often, for a fortnight Keep it in the jar for twelve or
fifteen months ; then strain it, and filter repeatedly until it is as clear as spring water.
Rinse phials or half pint bottles, with any white wine, drain them and filL Cork
and seal welL In six months it will be fit for use, if required, but will improve
greatly by age. — Robinson.
Tears of the Widow of Malabar, — To ten pounds of spirit (pale brandy), add 4
pounds of white sugar, and 4 pints of water, adding 4 drachms of powdered cinnamon,
48 grains of cloves, and the same quantity of mace ; colour with carameL
The Sighs of Love, — Spirit, water, and sugar as above. Perfume with otto of roses^
and slightly colour with cochineal.
Absinthe. — Take of the tops of wormwood, 4 pounds, root of angelica, calamus
aronuiticus, aniseed, leaves of dittany, of each, 1 oz. ; alcohol, four gallons.
Blacerate these substances during eight days, add a little water, and distill by a
LITHOGRAPHIC PRESS. 721
gentle fire until two gallone are obtwned. Thii is reduced to a proof ipirit. aad »
fiiv drop! of the oil of aolieed tddcd.
Tbeae foraii exempliry tbe character of aU kiodi of Hqneara. They are coloured
yellow by the colouriog matter of carlhamsi. Faum U produced by caramel ; rtd, hj
cochineal ; violet, by litmui, or archil ; Uiit by tbe *alphate of Indigo ; ^een, by mix-
ing the blue and the yellow together.
Ratafia, is tbe generic Dame, in France, of liqueurt compounded with alcohol,
(ugir, and the odoriferoua or flaTouring priDciplei of vegetablei. Bruiied cberrieB
with their atonei are infuied in ipirit of wine to make the ratafia of Grenoble de
Ttf—ire. The liquor being boiled and filtered, ii flsTOured, when cold, with tpirit
of Hoyam, made by dUtilling water off the bruined bitter kernels of apricots, and
mixing it with alcohol. Syrup of boy laurel and galango are also added.
LIQUID AMBAR. See Akbab, Liquid.
LlQ,lJOHlCE (.Glycyrrkiza Officinalit; from ^/yjlvi. sweet, and r^iia, a root). The
root only is employed ; these roots are thick, limg, and running deep in the ground.
Besides the use of liquoric roots in medicine, they are also employed in brewing,
and are pretty extensively grown for these purposes in some parts of England.
Liquorice requires a rich deep dry sandy soil, which, previous to forming a new plan-
tation, should be trenched to the depth of about three feet, aad a liberal allowance of
manure regularly mixed with the earth in trenching. The plants which are pr[>cured
by slipping them from tbo«e in old plantations are, either in February or Marcb,
dibbled in rows three feel apart, and from eighteen inches to two feet in the row.
1'hey require three summers' growth before being fit for nee, when the roots are
obtained b^ retrenching the whole, and they are then stored in sand for their preser-
vation unid required. — Pcttr LawioK.
LITHARGE (Eng. and Fr.; Clitte, Germ.) is the fused yellow protoxide of lead,
which OD cooling passes into a maw consisting of small six-sided plates, of a reddish
yellow colour and semitransparent. It generally contains more or less red lead,
whence the variationi of its colour, and carbonic acid, especially when it has been
exposed to the air for some lime. Bee Lead and Silveb, for its mode of preparation.
LITHIA is a simple earthy or alkaline labstance. discovered in the mmerals
called petalite and triphane. It is white, very caustic, reddens litmus and red
cabbage, and saturates acids with greet facility. When exposed to the air it attract^
humidity and carbonic acid. It is more soluble in water than baryta ; and has such
a strong affinity for it as to be obtained only in the state of a hydratf . It rontu
neutral salts with all tbe acids. It is most remarkable for its power of acting apon
or corroding ptatimuu.
LITHIUM is the metallic basis of lithia \ the latter substance consials of 100 of
metal, and ISSof oxygen. Neither lithium nor iu oxide are of any use in the arts.
LITHOGRAPHIC PRESS. Tbe lilhograpbic press in common use has long been
regarded as a very inadequate machine. The amount of maDual power required to work
it, and the slow speed at which, under the most favourable circumstances, copies can
be produced, disables lithography in its competition with letter- press. A career of bril-
liant success has attended the efibrta of scientific men towards speed and perfection in
this latter branch of tbe art ; and the present printing machines surpass the hand-presa
somewhat in the same ratio as does our express speed the jog-trot of our forefathers.
Tbe engravings Banexed.ji^i. 1141, lU!, will serve to illustrate Mestra. Kapier &
Sons' improvements upon tbe II- - - -
thognphio press. The machine
is arrunEed to be driven by steam
power 1 has belts, " crossed " and
"open," supposed to be in con-
nection with the engine, and to
run upon tbe pulleys a. a, c. The
crank pulley, n, is fixed on the
screw-spindle . D, and the other
two work loose, or "dead," on
the same spindle ; these bands
with their striking forks, a, ar«
arranged so as to be. brought al-
bemalely upon (he fixed pulley B,
and thus a reversing motion is
given to the screw. The not in
which the screw works is fixed "
to a crosspiece E, which braces tbe side fVames P P, together at bottom, while
the bar a, perform* tbe same office at lop ; the scraper-box, b, is sustained between
LITHOGRAPHY.
poiitiOD, allowing freEdom of BCLJon. Ch« rolUri i, j, are provided, which run id the
planed reciisiea, K, along the top of the main standards L.
The machine ii ihown with its tjmpan down, ready for starting; Ihis is effected bj
preuing lightl; upoD the lever, b, which raises a catch, aod allowi the weight >. to
descend in the direction of its present ioclination, and act upon the coDDectiooi with
the striking forks. «o ai to bring one of the bands upon the ^t pulley, b, and make
Ibe scraper and iti frames move forward. The retam i« caused b; the frame, r, com-
ing in contact with a stop c, which, yielding, acta upon the striking forks by lis bar
d, upon which it may he adjusted lo pve the travel required. On the return being
aceompliibed, the machine stops itself by a striking action against stop e, the catch t
falling in to prevent the weight descending to its full throw, and thus retalaiikg the
two bands upon the two dead pulleys, A and c, while the macbine is prepared Ibr
another impression.
The action of the scraper ii peculiar and novel ; it is balanced, so that iti tcndfocf
is to remain slightly raised, but in its forward movement, and at the point desired, it
ii made to descend by a stop fixed upon the top of the main standard, i^ into a poaitioD
vertical, or nearly so, in which position it is retained by its own onwaid progreas
ugaiuat strong abutments projecting from the framea, f ; on the retam it reaumea its
ruised position and pas!;es back without Imped imenL The scraper may be adjnsled lo
give the pressure desirfd, or the table on which the stone is pla^d regulated by tcrewi.
The advantages embodied in this machine will be at once recognised by tboae in-
terested. The polling down of the scraper, nod the labonr and inconvenience atten-
dant upon (hat operation, are entirely saperseded by the simple and effectual lalvc-like
movement ]nsl explained, which forms the ground work of this combination, although
it will alike apply to the press work by hand, and il the most striking novelty in the
LITHOGRAPHT. Thoagh this snbject belongs rather to the ana of taile and
design than to productive nunufhctnres, its chemical principles fidl within the pro-
vince of this Dictionary.
The term lithography is derived from Xifgi, a tloiu, and 7f>i^, wn'/i'a^, and desig-
nates the art of ihroving off impressions upon paper of figures and writing previouty
traced upon atone. The processes of this art are founded: —
I. Upon the adhesion to a grained or snoolhlj-polished limestone, of an eneanstic
fat which forms the lines or traces.
3. Upon the power acquired by the parta penetrated by this encauaiic, of attracting
to themselves, and becoming novered with, a printer's ink, having linseed oil Aw its
basis.
3. Upon the interposition of a film of water, which prevents the adhesion of the ink
in all the parts of the surfaoe of the stone not Impregnated with the encaustic.
A. Lutly, upon a pressure applied to the stone, such as to transfer to paper the
greater part of the ink which covers the greasy tracings or draitings of the encanatic
The lithographic stones of the best quality are still procured ^m the qoarty of
Solenhofen, a village at no great distance from Munich, whrra this mode of printing
had its birth. They resemble in Iheir aspect the yellowish -white lias of Bath, bnt their
geological place is much higher that the lias. Abundant quarries of these fine-gnined
limestones occur in the county of Pappenheim, along the banks of the Danube, pre-
senting slabs of eveiy required degree ot thickness, parted by regtilar seams, and nadj
LITHOGRAPHY. 723
for remoTal with rery little violence. The good quality of a litbographic stone is ge-
nerally denoted by the following characters ; its hue is of a yellowish grey, and uniform
throughout ; it is Iree from veins, fibres, and spots ; a steel point makes an impression
on it with difficulty ; and the splinters broken off from it by the hammer display a
conchoidal fracture.
The Munich stones are retailed on the spot in slabs or layers of equal thickness ;
they are quarried with the aid of a saw, so as to sacrifice as little as possible of the ir-
regular edges of the rectangular tables or plates. One of the broad faces is then
dressed, and coarsely smoothed. The thickness of these stones is nearly proportional
to their other dimensions ; and varies from 1} inches to 3 inches.
In each lithographic establishment, the stones receive their finishing, dressing, and
polishing ; which are performed like the grinding and polishing of mirror plate. The
work is done by hand, by rubbing circularly a movable slab over another in a
horizontal position, with fine sifted sand and water interposed between the two. The
style of work that the stone is intended to produce determines the kind of polish that
it should get For crayon drawing the stone should be merely grained more or less
fine according to the fancy of the draughtsman. The higher the finish of the surface
the softer are the drawings ; but the printing process becomes sooner pasty, and a
smaller number of impressions can be taken. Works in ink require the stone to be
more softened down, and finally polished with pumice and a little water. The stones
thus prepared are packed for use with white paper interposed between their faces.
Zinc plates are sometimes used in lieu of stones ; they are prepared by graining the
surface with fine sand, rubbed over by means of a small piece of the metal. Zinc
takes a finer surface than stone, and yields more delicate impressions ; but great care
is necessary in keeping it dry, so that it does not corrode ; this is almost the only
oljection to its more general use, for it is far more convenient to handle and move
about than heavy stones.
Lilhographic crayons, — Fine lithographic prints cannot be obtained unless the
crayons possess every requisite quality. The ingredients composing them ought to
be of such a nature as to adhere strongly to the stone, both after the drawing has
undergone the preparation of the acid, and during the press-work. They should be
bard enough to admit of a fine point, and trace delicate lines without risk of breaking.
The following composition has been successfully employed for crayons by MM. Ber-
nard and Delarue, at Paris : —
Pure wax (first quality) ..... 4 parts.
Dry white tallow soap - - - - - -2„
White tallow 2 „
Gum lac- - - - - - - -2„
Lamp black, enough to give a dark tint - - - 1 „
Oocasiondly copal varnish - - - - - 1 „
The wax should be melted over a gentle fire, and the lac, broken to bits, is then
added by degrees, stirring all the while with a spatula ; the soap is next introduced in
fine shavings ; and when the mixture of these substances is very intimately accom.
plished, the copal-varnish, incorporated with the lamp black, is poured in. The heat
and agitation are continued till the paste has acquired a suitable consistence ; which
may be recognised by taking out a little of it, letting it cool on a plate, and trying its
quality with a penknife. This composition, on being cut, should afford brittle slices
The boiling may be quickened by setting the rising vapours on fire, which increases
the temperature, and renders the exhalations less offensive. When ready, it is to be
poured into a brass mould, made of two semi-cylinders joined together by clasps or
rings, forming between them a cylindric tube of the crayon size. The mould should be
previously rubbed with a greasy cloth.
The soap and tallow are to be put into a small goblet and covered up. When the
whole is thoroughly fused by heat, and no clots remain, the black is gradually sprinkled
in with careful stirring.
Lithograpic ink is prepared nearly on the same principle : —
Wax - - • - - - - -16 parts.
Tallow 6 „
Hard tallow soap 6„
Shell-lac 12 „
Mastic in tears -8„
Venice turpentine ------ 1 „
Lampblack -------4„
The mastic and lac, previously ground together, are to be carefully heated in the
turpentine ; the wax and tallow must be added after they are taken off the fire and
when their solution is effected, the soap shavings are to be thrown in. Lastly, the lamp
3 A 2
724 LITHOGRAPHY.
black is to be well intermixed. Whenever the union is accomplished by heat, the
operation is finished ; the liqaor is left to cool a little, then poured out on tables, and,
when cold, cut into square rods.
Lithographic ink of good quality ought to be susceptible of forming an emulsion so
attenuated, that it may appear to be dissolved when rubbed upon a hard body in dis-
tilled or river water. It should flow in the pen, but not spread on the stone ; capa-
ble of forming delicate traces^^ and very black, to show its delineations. The most
essential quality of the ink is to sink well into the stone, so as to reproduce the most
delicate outlines of the drawing, and to afford numerous impressions. It must
therefore be able to resist the acid with which the stone is moistened in the prepara-
tion, wiUiout letting any of its greasy matter escape.
M. de Luteyrie states that after having tried a great many combinations, he gives
the preference to the following : —
Tallow soap dried - - - dO parts.
Mastic in tears - - - - 30 „
White soda of commerce • - 30 ^
Shell-lac 150 „
Lamp-black - - - - 12 „
The soap is first put into the goblet and melted over the fire; the lac being added
it fuses immediately ; the soda is then introduced, and next the mastic, stirring all
the while with a spatula. A brisk fire is applied till all these materials are melted
completely, when the whole is poured out into the mould.
The inks now prescribed may be employed either with the pen and the hair pencil,
for writings, black-lead drawings, cujua Hnta, mixed drawings, those which represent
engravings on wood (woodcuts), &c. When the ink is to be used it is to be rubbed
down with water, in the manner of China ink, till the shade be of the requisite depth.
The temperature of the place ought to be from 84^ to 90^ Fahr., or the saucer in
which the ink stick is rubbed should be set in a heated plate. No more ink should
be dissolved than is to be used at the time, for it rarely keeps in the liquid state for
24 hours ; and it should be covered or corked up.
Autographic paper. — Autography, or the operation by which a writing or a drawing
is transferred ft'om paper to stone, presents not merely a means of abridging labour,
but also that of reverting the writings or drawings into the direction in which they
were traced, whilst, if executed directly upon the stone, the impression given by it is
inverted. Hence, a writing upon stone must be inverted fh>m right to left to obtain
direct impressions. But the art of writing thus is tedious and difficult to acquire,
while, by means of the autographic paper and the transfer, proo6i are obtained in the
same direction with the writing and drawing.
Autographic ink. — It must be fatter and softer than that applied directly to the
stone, so that though dry upon the paper, it may still preserve sufficient viscidity to
adhere to the stone by mere pressure.
To compose this ink, we take —
White soap .... 100 parts.
White wax of the best quality - 100 „
Mutton suet - - - - SO „
Shell-lao .... 50 „
Mastic ..... 60 „
Lamp black - - - 30 or 35 „
These materials are to be melted as above described for the lithographic ink.
Lithographic ink and paper. — The following recipes have been much oom-
mended : —
Virgin or white wax - -> 8 parts:
White soap - - - - 2 „
Shell.lac • - - - 2 „
Lamp black .... 3 table-spoonfhls.
Preparation. — The wax and soap are to be melted together, and before they be-
come so hot as to take fire, the lamp black is to be well stirred in with a spatula, and
then the mixture should be allowed to bum for 30 seconds ; the flame being ex-
tinguished, the lac is added by degrees, carefully stirring all the time; the vessel
is to be put upon the fire once more in order to complete the combination, and
till the materials are either kindled or nearly so. After the flame is extinguished, the
ink must be suffered to cool a little, and then put into the moulds.
With the ink crayons thus made, lines may be drawn as fine as with the point of
the graver, and as full as can be desired, without risk of its spreading in the carriage.
Its traces will remain unchanged on paper for years before being transferred.
Some may think it strange that there is no suet in the above composition^ but it has
LITHOGRAPHY. 725
been found that ink containing it is only good when used soon after it is made, and
when immediately transferred to the stone, while traces drawn on paper with the suet
ink become defective after 4 or 5 days.
Lithographic paper. — Lay on the paper 3 snccessiye coats of sheep-foot jelly,
1 layer of white starch, 1 layer of gamboge.
The first layer is applied with a sponge dipped in the solution of the hot jelly, very
equally over the whole surface, but thin ; and if the leaf be stretched upon a cord, the
gelatine will be more uniform. The next two coats are to be laid on, until each is dry.
The layer of starch is then to be applied with a sponge, and it will also be very thin
and equal. The coat of gamboge is lastly to be applied in the same way. When the
paper is dry, it must be smoothed by passing it through the lithographic press ; and
the more polished it is, the better does it take on the ink in fine lines.
Transfer, — When the paper is moistened, the transfer of the ink from the gamboge
is perfect and infallible. The starch separates from the gelatine, and if^ after taking
the paper off the stone, we place it on a white slab of stone, and pour hot water over
it, it will resume its primitive state.
The coat of gamboge ought to belaid on the same day it is dissolved, as by keeping
it becomes of an oily nature ; in this state it does not obstruct the transfer, but it
gives a gloss to the paper which renders the drawing or tracing more difficult, espe-
cially to persons little accustomed to lithography.
The starch paste can be employed only when cold, the day after it is made, and
after having the skin removed from its surface.
A leaf of such lithographic paper may be made in two minutes.
In transferring a writing, an ink drawing, or a lithographic crayon, even the im-
pression of a copper-plate, to the stone, it is necessary, 1, that the impressions be
made upon a thin and slender body like common paper ; 2, that they may be de-
tached and fixed totally on the stone by means of pressure ; but as the ink of a draw-
ing sinks to a certain depth in paper, and adheres rather strongly, it would be
difficult to detach all its parts, were there not previously put between the paper and
the fraces a body capable of being separated ft'om the paper, and of losing its ad-
hesion to it by means of the water with which it is damped. In order to produce this
effect, the paper gets a certain preparation, which consists in coating it over with a
kind of paste ready to receive every delineation without suffering it to penetrate into
the paper. There are different modes of communicating this property to paper.
Besides the above, the following may be tried. Take an unsized paper, rather
strong, and cover it with a varnish composed of: — Starch, 120 parts } gum arabic,
40 parts ; alum, 20 parts.
A paste of moderate consistence most be made with the starch and some water,
with the aid of heat, into which the gum and alum are to be thrown, each previously
dissolved in separate vessels. When the whole is well mixed, it is to be applied, stiU
hot, on the leaves of paper, with a flat smooth brush. A tint cf yellow colour may
be given to the varnish with a decoction of the berries of Avignon, commonly called
French berries by our dyers. The paper is to be dried, and smoothed by passing
under the scraper of the lithographic press.
Steel pens are employed for writing and drawing with ink on the litbographio
stones i in many establishments a sable brush is more frequently used.
Engraving on atones for maps, geometrical drawings of every kind, patent inven-
tions, machinery, &c., is performed with a diamond point as clearly and distinctly as
if executed on copper or steel platea; to print these engraved stones, the ink should
be laid on with a dabber, not a roller. Another method is by preparing the surface
of the stone with a thin oovering, or etehmg ground, of gum and black, upon which
the design is traced or engraved with an etching point ; it then appears in white lines
upon a black surfiEtce. In this state the stone is taken to the printer, who applies ink
to the engpraved part, and washing off the gum, the drawing appears in blach linea
upon the white surface of the stone, and after being submitted to the process of
fixing, described below, is ready for printing.
Lithotint, a process of drawing upon stone was adopted, first, by Mr. J. D. Hard-
ing, a few years back, and since by one or two other artists *, several works were at
the time executed by this method, which consists in painting the subject with a
camel hair pencil, dipped in a preparation of liquid lithographic chalk, using the
latter as if it were an ordinary colour, or Indian ink, sepia, &c The results of this
process were, however, so uncertain in printing, that it has been almost, if not en-
tirely, abandoned.
The process of printing a subject executed in litho^phy is as follows : — The
dMiwing is first executed by the artist on the stone m as perfect and finished a
manner as if done on paper or card-board : the stone is then washed over with nitrio
acid, diluted with gum, which neutralises the alkali,. or soap, contained in the chalky
3 A 3
726 LITMUS PAPER.
fixes the dravinfi;, and cleanses the stone at the same time : this is technically called
etching. The acid is then washed off with cold water, and aoj particles of the
crayon or other substances which may haTe adhered to the surface^ are remoTed by
the application of a sponge dipped in spirits of turpentine : the stone is now ready
for printing : it is slightly wetted, charged with printing-ink by means of a roller,
the sheet of paper, which is to receive the impression, is laid on it in a damp state,
and the whole is passed throogh the press.
Chrcmolithography, or printing in colours from stones (xp^fM, coloar), is a com-
paratively recent introduction, but has been brought to such perfection, that works
of art of the highest pictorial excellence are sometimes so closely imitated, as to
deceive very competent judges. A portrait of Shakspeare, for example, executed
in chromolithography by Mr. Vincent Brooks, of London, from an old oil painting,
is so marvellous a copy of the original as almost to defy detection. Chromolitho-
graphy, as a beautiful medium of illustration, is now in very general use: the process
may be thus described. A drawing of the subject, in outline, on transfer tracings
paper, is made in the ordinary way: when transferred to a stone, this drawing is
called the keys^tone^ and it serves as a guide to all the others, for it must be transfeired
to as many different stones as there are colours in the subject ; as many as thirty
stones have been used in the production of one coloured print The first stone re-
quired, generally for flat, local tints, is covered with lithographic ink where the
parts should be of solid colour: the different gradations are produced by rub-
bing the stone with rubbing-stuff, or tint-ink, made of soap, shell lac, &e. 9te^ and
with a painted lithographic chalk where necessary; the stone is then washed over with
nitrons acid, and goes through the entire process described above. A roller charged
with lithographic printing-ink is then passed over it to ascertain if the drawing
comes as desired ; and the ink is immediately afterwards washed off with tnrpentine:
if satisfactory, this stone is ready for printing, and is worked off in the requisite
colour; the next stone undergoes the same process for another colour, and so with
the rest till the work is complete: it will of course, be understood, that before any
simple impression is finished, it will have to pass through as many separate printings
as there are drawings on stones. The colours used in printing are ground up with
burnt linseed oil, termed varnish. — J. D.
LITHOM A.RGE. A silicate of alumina, in many respects resembling China clay or
kaolin, which see.
LITMUS (Totcmefio/, Fr. ; Lackmus, Germ.) is prepared in Holland from the
species of lichen called Lecanora tartarea, lioccdh tartarea. The ground lichens are
first treated with urine containing a little potash, and allowed to ferment for several
weeks, whereby they produce a purple-red ; the coloured liquor, treated with quick-
lime and some more urine, is set again to ferment during two or three weeks, then
it is mixed with chalk or gypsum into a paste, which is formed into small cubical
pieces by being pressed into brass moulds, and dried in the shade. Litmus has a
violet-blue colour, is easy to pulverise, is partially soluble in water and dilute alcohol,
leaving a residuum consisting of carbonate of lime, of clay, silica, gypsum, and oxide
of iron combined with the dye. The colour of litmus is not altered by alkalies, but is
reddened by acids ; and is therefore used in chemistry as a delicate test of acidity,
either in the state of solution or of unsized paper stained with it. See Lichen.
The preparation of litmus has been- described by Ferber, Morelos, and others.
Dr. Pereira, writes, *' Litmus is imported from Holland, in the form of small, rec-
tangular, light, and friable cakes of an indigo blue colour. Examined by the mi-
croscope, we find sporules and portions of the epidermis and raesothallns of some
species of lichen, moss, leaves, sand, &c The odour of the cakes is that of indigo
and violets. The violet odour is acquired while the mixture is undergoing fermen-
tation, and is common to all the tinctorial lichens. It has led some writers into the
error of supposing that the litmus makers use Florentine orris in the mannHscture
of litmus. The indigo colour depends on the presence of indigo in the litmus cakes."
LITMUS PAPER. Paper coloured with an infusion of litmus, used as a test fbr
the presence of acids.
Faraday, in his Chemical Manipulation^ recommends an infusion of one ounoe of
litmus, and half a pint of hot water. Bibulous paper is saturated with this. Professor
Graham prefers good letter paper to the unsized paper. In order to obtain -very de-
licate test-paper, the alkali in the litmus must be almost neutralised by a minute portion
of acid.
LITTORAL (a geological term). Belonging to the sea-shore.
LIVI-DIBI. Another name for Divi-divi. See Leather.
LIXIVI ATION (^Lessivage, Fr. ; Auslagen^ Germ.) signifies the abstraction ffy
water of the soluble alkaline or saline matters present in any earthy admixture ; as
from that of quicklime and potashes to make potash lye, from that of effloresced alum
schist to make aluminous liquors, &c.
LLAMA. 727
LLAMA A genus of animalfl belonging to the clam Mammcdia, order Un^uhic^
family Bmndsy and tribe Camelina. They are the camels of South America, to
which country they are confined. In the wild state the llamas keep together in herds
of from one to two hundred. There are two distinct species found wild in South
America, inhabiting the Peruvian Alps, the Pampas, and the mountains of Chili.
These animals are used as beasts of burthen ; cords and sacks, as well as stufis for
ponchos, &e,, are fabricated trmn their wool ; and their bones are converted into instru-
ments for weaving the same. The Alpaca, which is a variety of the llama, has
given its name to a cloth manufactured from its hair; and this has become so valuable,
that attempts have been made to naturalise the animal in Europe. The success,
however, which has attended these attempts has not been great The following note
from the Penny Cydopediat article Llama, is important.
" In reference to the wool, we may here state that a herd of thirty-six, including the
kinds called llamas, alpacas, and vicunas or vigonias, were sent from Lima (Peru)
and Conception (Chili) to Buenos Ayres by journeys of two or three leagues. To
those who may be inclined to import these animals, it may be necessary to state that
they were fed during the journey with potatoes, maize, and hay. As soon, however,
as the potatoes were exhausted, constipation came on so obstinately, that medical
relief was required. They were shipped as a present from Godoy, the Prioce of
Peace, to the Empress Josephine, but only eleven arrived at Cadiz in 1808, just as
Godoy fell into disgrace. Here two died, and the rest were near being thrown into
the sea by the infuriated rabble, in their detestation of the late minister and minion.
The poor llamas were however saved frxmi the tender mercies of the populace by the
governor of Cadiz, and were consigned to Bon Francisco de Theran of Andalusia,
who bad a fine menagerie at San Lucar de Barrameda. When the French occupied
the province, Marshal Soult protected them ; and M. Bury St. Vincent, who was
with the army, studied their habits, and executed drawings of them, which were lost
at the battle of Vittoria. M. Bury paid great attention to their wool, and some from
each kind was sent to the Academy of Sciences at Paris. From the report of the
French naturalist and the philosophical Spaniard, it would appear that the fleece of
the alpa-vigonia (produced by a cross between a vigonia and an alpaca) has much
grreater length than any other variety, and is six times heavier."
The following is from Jamede aUtory of tke WorHed Manufacture in England,
p; 662 : —
To commence with the earliest mention of the alpaca, we must recur to so early a
period as the year 1525, when Pizarro and. his ferocious companions invaded Peru.
It is related by the Spanish historians, that they found there four varieties of sheep ;
two, the g^naco and the vicuna, in a wild state, ranging the mountainous tracts
of South America; and the others, the llama and the pacos; or alpaca, domesti-
cated. The former of these domestic animals, partaking somewhat of the nature and
size of the Arabian camel, was in like manner employed as a beast of burden.
Though in many features similar to the llama, the alpaca bad several clear marks
of distinction, and among others was less, and the fleece much longer and softer in
fibre. In the sixteenth century, and even from the remotest times, the Peruvians
being comparatively (to the other tribes of the great continent of America) a civilised
people, and well acquainted with the arts of spinning and weaving, fabricated from
alpaca wool textures of much delicacy and beauty, which were highly prized as
articles of dress. And that the use of them had prevailed for centuries is demonstrated
by the opening of several very ancient tombs of the Peruvians, in which the dead
had been enwrapped in stuffs made from the fleece of the alpaca.
In general, the alpaca ranges about four feet in height, the size of a full grown
deer, and, like it, is of graceftd appearance. Its fleece is superior to the sheep in
length and softness, averaging six inches (the length of the -staple of the alpaca
fleece is on an average much less than formerly, probably fhmi being shorn oftener),
and sometimes it has been procured even of an extraordinary length ; a specimen
shown at the Great Exhibition, by Messrs. Walter Milligan and Son, reaching to
forty-two inches in length. The fleeces, when annually shorn, range from five to six
pounds. Contrary to experience in other descriptions of wool, the flbre of the Al-
paca fleece acquires strength without coarseness ; besides, each filament appears
straight, well formed, and free from crispness, and the quality is more uniform
throughout the fleece. There is also a transparency, a glittering brightness upon
the surface, giving it the glossiness of silk, which is enhanced on its passing through
the dye-vat. It is also distinguished by softness and elasticity, essential properties
in the manufacture of fine goods, being exempt from spiral, curly, and shaggy defects ;
and it spins, when treated properly according to the present improved method, easily*
and yields an even, strong, and true thread. With all these remarkable qtialities, it
was long before the value of alpaca wool was known or appreciated in thiB country.
3 A 4
728 LLAMA.
Recurring to the appticat'ion of the alpaca fleece to manufactizring purposes in
England, it was long delayed. Though so early as the year 1807, the British troops
retumiogfrom the attack of Buenos Ayres brought with them a few bags of this wool,
which were submitted for inspsction in London ; but, obsenres Walton in his work
on alpaca, ** owing to the difficultv of spinning it, or the prejudice of our manufac-
turers, it did not then come into notice," and for more than twenty years the attempt
does not seem to hare been renewed ; thus depriving^ for that period, the country of
the advantage derived from this notable manufacture.
According to the best authorities, the first person in England who introduced a
marketable fabric made from this material was Mr. Benjamin Ontram, a scientific
manufacturer of Greetland, near Halifax, who, about the year 1830, sormounted,
with much difficulty, the obstacles encountered in spinning the wool, and eyentualiy
produced an article which sold at high prices for ladies carriage shawls and cloak-
ings; but their value arose more from being rare and curious articles than from
intrinsic worth.
These were, it is well established, quite destitute of the peculiar gloss and beauty
which distinguish the alpaca lustres and fabrics of later times, and after a short period
the manufacture was abandoned.
About the same time as Mr. Outram was weaving goods from alpaca, the wool
attracted the notice of the Bradford spinners. Messrs. Wood and Walker spun it to
some extent for camlet warps used in the Norwich trade. Owing to the cheapness of
alpaca wool during the first years of its consumption in England, it was occasionally
employed instead of English hog wool for preparing lasting and camblet warps, being
spun to about No. 48.
The earliest manufacture of the alpaca wool into goods at Bradford appears to
have occurred under these circumstances. In the commefacement of 183S some
gentlemen, connected with the trade to the west coast of South America, were on a
visit at the house of J. Garnett, Esq., of Clithero, and, on their alluding to the diffi-
culty of meeting with suitable returns for goods forwarded to that part of the worid,
he suggested to them the transmission of alpaca wool, and ofiTered, if they would send
him a few pounds weight, to ascertain its value for mannfiicturing purposes. In a
few months he received some samples of alpaca wool, which, on the 2nd of October,
1832, he forwarded to Messrs. Horsfall, of Bradford, with a request that they would
test its value. Accordingly they fabricated from this wool a piece resembling heavy
camblet, which they showed to the Leeds merchants ; but the piece, not developing
any peculiar qualities of alpaca, did not please, so that Messrs. Horsfall were not
encouraged to proceed further with experiments. However, in the same year MeasrsL
Hoyam, Hall, and Co., spirited merchants of Liverpool, perceiving the value of the
alpaca wool, directed their agents in Peru to purchase and ship over all the parcels
of alpaca wool they could meet with ; some of which, being sent to the Bradford
district, was spun and manufactured by several parties there. The pieces chiefly
fabricated from alpaca in the neighbourhood of Bradford were figures made with
worsted warp and alpaca weft, the figure being raised and lustrous like onion
damasks. These goods were in vogue only for a limited time, for neither the figured
nor plain ones seem to have suited the public taste.
Until the introduction of cotton warps into the worsted trade, it may safely be
averred that the alpaca manu&cturo had not been developed, and would never have
made much progress without being combined with cotton or silk warp. To Titus
Salt, Esq., of Bradford, must undoubtedly be awarded the high praise of finally over-
coming the difficulties of preparing and spinning the alpaca wool so as to produce an
even and true thread, and,J[)y combining it with cotton warps, which had then (1836)
been imported into the trade of Bradford, improved the manufacture so as to make it
one of the staple industries of the kingdom. He has, by an admirable adaptaticm of
machinery, been enabled to work up the material with the ease of ordinary wool, and
thus present beautiful alpaca stnfib at a reasonable rate. Every previous attempt had
been made, so far as can be ascertained, with worsted warps, with whidi the alpaca
did not easily assort
About the year 1836 the alpaca trade had become established, and has since risen
to much importance. After this period the manufacture rapidly extended. The
great mercantile house of A. and S. Henry took very hirge quantities of alpaca stn£Bk
which began to be made in an endless variety of goods suited JtK>th for male and
female dress, including scarfs, handkerohieft, and cravats, plain and figured goods,
both with silk and cotton warp, for ladies* dresses, dyed alpaca checks of be^tifU
texture, and a variety of grograms, codringtons, silk-striped, diecked, and figured
alpacas and alpaca linings- The demand for these various alpaca fabrics during the
period between 1841 and 1846 remained uniform and steady.
At the commencement of the manufacture of alpaca goods with cotton warps (silk
LLAMA.
729
was Dot ased), the weft was spun from fine qnalities of the wool into low numbers,
and the pieces were made mnch richer and hearier than has been the case more re-
cently, the demand haying altered in ikyour of lighter and less costly cloth.
Most of the alpaca wool broaght into the United Kingdom is unshipped at Liver-
pool, but a small portion is also carried to London. At these two ports, it may be
asserted, the whole imported into this country is landed* It arrives in small bales,
called ballots, weighing about seventy pounds, and is generally in an impure state,
with different qualities mixed. Like the fleece of the sheep, that of the alpaca is
composed of different qualities, so that the portion growing on the hind quarters is of
an inferior description. The wool is sorted into about eight different qualities, each
fitted for a particular class of goods. Owing to the dirty state of the fleeces, and the
peculiar nature of the dusty particles arising during the progress of sorting, the opera-
tion is an unhealthy one, unless great care be taken by ventilation to counteract this
baneful effect After being sorted, it is at Saltaire washed and combed by machinery.
Until of late years it was combed wholly by hand, and the combs used for the purpose
were of a deeper pitch than those usually adopted for preparing sheep's wool, that
is, those combs had a larger number of teeth than ordinary. The next process is to
draw the sliver, which is perfected by an improved gill machine, especially adapted
for this material. And here, in combing and preparing the alpaca wool, so as to
make a clean, even, and glossy thread, lay the grand difficulty in the way of applying
the alpaca fibre to the worsted mannfocture, and which was so successfully surmounted
by Mr. Salt
The main articles now manufactured from alpaca wool consist of alpaca lustres,
which are dyed, and alpaca mixtures, which are undyed, and both are made of cotton
or silk warp. These plain goods may from their extensive and steady use be termed
stock articles. Large quantities of fiincy alpacas are made, but they are rapidly vary-
ing and are distinguished by innumerable names. The material is at present much
shorter in staple than formerly, owing to the alpaca being shorn oftener, so that it is
now commonly from five to eight inches in length. Nearly all the alpaca wool con-
sumed in England is worked up in the Bradfonl district
Dating from the year 1834, when the importation of alpaca wool sprung up as a
permanent branch of commerce, the demand in this country has, with the exception
of the last two years, on the whole been a growing one. Mr. Walton, in his work on
the alpaca, exhibits the quantities export^ chiefly to .England until the year 1843,
when the tariff law having come into operation, the returns began to be more correctly
framed, and the alpaca wool was then classed by itself
Tean.
Lbt.
Yean.
Lbs.
1834
1835
1836
1837
1838
5,700
184,400
199,000
385,800
459,300
1839
1840
1841
1842
1,825,500
1,650,000
1,500,000
1,443,299
In the interval of these twelve years, the price had, with the demand, progressively
increased : the price in 1834 only amounted to about eightpence halfpenny per pound :
next year it reached nearly tenpence; the year after one shilling ; in 1638. to up-
wards of one shilling and threepence halfpenny ; and in 1839, to one shilling and
fourpence per pound.
Since the year 1842, the returns of alpaca wool imported into this country are of a
more reliable character. The following table has been drawn up from data furnished
by the Board of Trade.
Yean.
Lbi.
Yean.
Lbi.
1843
1,458,032
1850
1,652,295
1844
635,357
1851
2,013,202
1845
1,261,905
1852
2,068,594
1846
1,554,287
1853
2,148.267
1848
1,521,870
1854
1,267,513
1849
1,655,300
1855
1,446,707
730 LOCKS.
AstonishiDg as it may appear, the bulk of these importations have been consumed
in England, and the quantity re-shipped to the Continent has been comparatively
trifling in amount
Duriog the last ten years, the prices have fluctoated considerably. In 1844, one
shilling and eightpence per pound was quoted as the price of the white fleece, and two
shilliags for th« black one. In the year 1855, according to the price currents, the
average rates were thns quoted :
Alpaca, best white
Ditto, brown and black
Vicuna, best dark coloured -
Llama ....
«.
d. «.
d.
2
6 to 2
8
2
6 „ 2
8
3
0 „ s
6
0
104 M 1
3
Com
- 5 qrs. or 40 bushels.
Straw -
- 36 trusses or 1 1 cwt
64 lbs.
Old hay -
- 18 cwt
New hay
- 19 cwt 32 lbs.
Bricks -
- 600.
TUes -
- 1000.
Lead ore (
in Derbyshire) 9 dishes or
nearly 3 cwt
Bulrushes
- 63 bundles.
Mortar -
- 27 feet
But these quotations are undoubtedly higher for alpaca wool than the prices realised,
which of late years have ranged from two shillings and twopence to two shillings and
sixpence per pound.
LOAD. A burthen or freight As the various quantities of material contained in a
load cannot but be useful, the following table is borrowed from Afr, P. L. SimmowU
" Trade Products," J*e.
Coffee, in bags - IS cwt
Rice - - 10 cwt
Timber—
1 inch plank - 600 square feet
1 J inch „ - 400 „ „
2 inch „ - 300 „ „
24 inch „ - 240 „ „
3 inch „ - 200 ^ n
3jinch „ - 170 „ „
4 inch „ - 150 „ „
LOADSTONE, MAGNETIC IRONSTONE. (Per oxydnU, Fr.; MagHetei^en^
stein. Germ.) An iron ore ccmsisting of the protoxide and peroxide of iron in a state
of combination.
It was first discoTered in Magnesia, and from that province has been derived the
name Magnet applied to this ore of iron. The term loadstone, however, is given to
those specimens which are powerfully msgnetic only. A considerable number of the
igneous rocks containing iron are magnetic, and many magnetic oxides of iron are
found in England, especially near Penryn in Cornwall, near Brent in Devonshire, at
Rosedale in Yorkshire, and some other places. See Iron.
LOAM. (^Terre linumense, Fr. ; Lehnit Germ.) A native clay mixed with quarts
sand and iron ochre, and occasionally with some carbonate of lime.
** More commonly we find sand and clay or clay and marl intermixed in the same
mass. When the sand and clay are each in considerable quantities, the mixture is
called * loam.' '*—Xi««.
LOCKS. Although locks are distinctly a manufacture, yet they were not em-
braced in former editions of this work* the chief cause of this being the desire on the
part of Dr. Ure to limit the articles of the dictionary to such manufactures as were
not comprehended within his meaning of the term handicraft
The lock manuflicture is essentially one of handicraft, and seeing that these vo-
lumes could not possibly enter into any detailed description of this and numerous
other trades, as watchmaking and the like, it has been determined that a brief notice
of the several kinds of locks alone shall find a place in its pages.
The lock manufacture of this country is confined almost exclusively to Wdrer^
hampton and the neighbouring village of Willenhall. There are very few large
manufactories, almost all kinds of locks being made by small masters, employing
from half a dozen to a dozen men.
In nearly every kind of lock, a bolt shoots out from the box or lock, usually of an
oblong shape, and catches in some kind of staple or box fixed to receive it In some
a staple enters the lock, and the bolt passes through the staple within the lock. The
lock of a room door is of the first character. The lock of a writing desk, or ordi-
nary box, is of the second kind. The key is merely a bent piece of iron which, on
entering the lock, can move freely and push forward the bolt To the bolts of su-
perior locks springs are attached, and the force required to turn the key in a lock is
the force necessary to overcome the resistance of the springs. The following two
figures, 1 143, 1 144, represent the character of a lock with wards or wheels whidi ara
introduced to give safety. Fig. 1 143 is an ordinary back spring lock, representing the
bolt half shot ; a' a'' are notches on the under side of the bolt connected by a curved
(he bolt it -withdnun, the Doleh a' mu in the rim ; *ben the bol) ii ibot, the notch
a" TciU in the nine mumer. The action of the key and irardi i» ihonu in ^.
lUi. The ciured uiecei of melal are the waidj ; siid ihere are two clefts in iha
bit of the ke7 to enahle it to move vithoat intemiption.
The tambler lock ii iho»u in its moM limpla form in jSj. lUS. Here the boll hu
two (Iota a a in the opper put; and behind the bolt ii a kind oflalchi which c(
a projecting piece of metal i e. thii is the tDmUeT
which moTCi freelj On a pivot at the other end.
When ibe boll ia folly ibot the prcgecling piece
of metal fall* into one notob ) and when wilh-
drawQ, it falla into the other. It will be eri- | — l --
dent here that the action of the kej ii to raiie <
the tumbler, lo that the bolt hai &ee motion ; MH
thii action will be intelligible by tracing the ac-
tion of the key on the dotted linea These tnm-
bler locks are greatly varied in characler ; hut
in principle they are ■■ aboie described. Nu-
merous *el] known locks have been patented,
the moat remarkable being Chubb'a lock, which
has beeo fully described by the inventors in a
paper r«d before the Institution of Civil Engineers ; and also in an excellent treartse on
loeka lo be found in Mr. Weale's seriea of uaeful manuals. This lock is essentially a
tumbler lock, it being fitted up with no less than six tumblers ; and the key baa to
raise by a series of steps these, before the bolt ia fVee lo move. It will be obvioos,
that unless the key is exactly fitted to move these, Ihere ia no chance of moving the
bolt, [c bis paper already allnded to, Mr. Chubb says —
" The number of changes which may be effected «i the keys of a three inch
drawer lock ia 1 x S ■ S k4 > S x 6 — 730, the number of different combinations
which may be made on the six steps of unequal lengths, withont altering the length
of either slepL The height of the ahortest step is however capable c^ being reduced
90 times; and each lime of being reduced, the TZO combinations may be repeated;
therefore 730 ■ SO^ 14.400 changes." By effecting changes of this character there-
fore, almost any number of combinations can be produced. The Bramah lock has
been long celebrated, and most deservedly so. Notwithstanding the tact that this
lock was picked by Ur. Hobba after having the lock in his poiseaaion far sixteen
days, it appears to ua that It moM fully juatifiea the boaat made by Mr. Bramah in
his "IHitrialHm Da tAt Cmulnictiim d/'XocAx." " Being confident," he says, " that I
have contrived a security which no instrument bnt its proper key can reach, and
which may be ao applied as not only to defy the art and ingennity of the most akilftal
workman, bnt to render the almost force ineffectual, and thereby to seent« wbal is
most valued as well from dishoiKst servants as from the midnighl ruffian, I think
myself at liberty lo declare (what nothing but the discovery of an inbllible remedy
would justify my disclosing) that all dependence on the mviolable security of locks,
even of those which are conatrocted on the best principle of any in general nse, is
ftillBcious." He then ptooeeds to demonstrate the impeifecttoos of ordinary hicks
and to describe his own.
" The body of a Bramah lock msy be considered as formed of two eoneentrie hrass
barrels, the oal«r one fixed, and the inner rotating within it. The inner barrel has
a pn^eding stnd. which, while the barrel is rotating, comes in contact with the bolt
in stieh a way a* to shoot or lock it ; and thus the Mod serves the same ptirpose m
732 LOCKS.
the bit of an ordinary key, rendering the construction of a bit to the Bromah key
unnecessary. If the barrel can be made to rotate to the right or left, the bolt can be
locked or unlocked, and the problem is, therefore, how to insure the rotation of the
barrel. The key, which has a pipe or hollow shaft, is inserted in the keyhole npon
the pin, and is then turned round; but there roost be a nice adjustment of the me-
chanism of the barrel before this turning round of the key and the barrel can be in-
sured. The barrel has an external groove at right angles to the axis, penetrating to
a certain depth ; and it has also several internid longitudinal grooves from end to
end. In these internal grooves thin pieces of steel are able to slide, in a direction
parallel with the axis of the barrel. A thin plate of steel called the locking plate, is
screwed in two portions to the outer barrel, concentric with the inner barrel ; and at
the same time occupying the external circular groove of the inner barrel ; this plate
has notches, fitted in number and size to receive the edges of the slides which work in
the internal longitudinal grooves of the barrel If this were all, the barrel could not
revolve, because the slides are catching in the grooves of the locking plate ; but each
slide has also a groove, corresponding in depth to the extent of this entanglement ; and
if this groove be brought to the plane of the locking plate, the barrel can be turned,
so far as respects the individual slide. AH the slides must, however, be so adjusted,
that their grooves shall come to the same plane ; but, as the notch ia cut at diderent
points in the lengths of the several slides, die slides have to be pushed in to different
distances in the barrel, in order that this juxtaposition of notches may be insured.
This is effected by the key, which has notches or clefts at the end of the pipe equal in
number to the slides, and made to fit the ends of the slides when the key is in-
serted ; the key presses each slide, and pushes it so far as the depth of its cleft will
permit ; and all these depths are such that all the slides are pushed to the exact
position where their notches all he in the same plane ; this is the plane of the locking
plate, and the barrel can be then turned." (Tondingon on the Corutructian o/Locig,)
In this work the details on construction are given with great clearness.
The American bank locks, especially that of Messrs. Day and Nowall, have ex*
cited much attention. Their English patent describes it thus: —
** The object of the present improvements is the constructing of locks in such
manner that the interior arrangements, or the combination of the internal movable
parts, may be changed at pleasure according to the form given to, or change made in,
the key, without the necessity of arranging the movable parts of the lock by hand,
or removing the lock or any part thereof from the door. In locks constructed on
this plan the key may be altered at pleasure ; and the act of locking, or throwing out
the bolt of the lock, produces the particular arrangements of the internal parts,
which correspond to that of the key for the time being. While the same is locked,
this form is retained until the lock is unlocked or the bolt withdrawn, upon which
the internal movable parts return to their original position, with reference to each
other ; but these parts cannot be made to assume or be brought back to their original
position, except by a key of the precise form and dimensions as the key by which they
were mside to assume such arrangement in the act of locking. The key is change-
able at pleasure, and the lock receives a special form in the act of locking according
to the key employed, and retains that form until in the act of unlocking by the same
key it resumes its original or unlocked state. The lock is again changeable at plea,
sure, simply by altering the arrangement of the movable bits of the key ; and the
key may be changed to any one of the forms within the number of permutations of
which the parts are susceptible." — April 15, 1851.
Mr. Hobbs who has been carrying out the manufacture of American locks in this
country has introduced an inexpensive lock, which he calls a protector lock. The
following description is borrowed ft'om Mr. Charles Tomlinson*8 Treatise on tke
Construction of Locks : —
" When the American locks became known in England, Mr. Hobbs undertook
the superintendence of their manufacture, and their introduction into the commercial
world. Such a lock as that just described must necessarily be a complex piece of
mechanism ; it is intended for use in the doors of receptacles containing property of
great value ; and the aim has been to baffle all the methods at present known of
picking locks, by a combination of mechanism necessarily elaborate. Such a lock
must of necessity be costly ; but in order to supply the demand for a small lock at
moderate price, Mr. Hobbs has introduced what he calls a protector kxk. This is a
modification of the ordinary six-tumbler lock. It bears an affinity to the lock of
Messrs. Day and Newall, inasmuch as it is an attempt to introduce the same prin-
ciple of security against picking, while avoiding the complexity of the changeable
lock. The distinction which Mr. Hobbs has made between secure and insecure locks
will be understood from the following proposition, viz. * that whenever the parts of
a lock which come in contact with the key are so affected by any pressure applied to
LOCKS.
73a
the bolt, or to that portion of the lock by which the bolt is withdrawn, as to indicate
the pointsof resistance to the withdrawal of the bolt, such a lock can be picked.'
Fig, 1147 exhibits the internal mechanism of this new patent lock. It contains the
usual contrivances of tumblers and springs, with a key cut into steps to suit the dif-
ferent heights to which the tumblers must be raised. The key is shown separately
in JiQ, 1148. But there is a small additional piece of mechanism, in which the
tumbler stump shown at s in Jigs. 1146 and 1147 is attached ; which piece is intended to
work under or behind the bolt of the lock. In Jig. 1 147, 6 is the bolt ; t < is the front
1146
1148
1147
or foremost of the range of six tumblers, each of which has the usual slot and notches.
In other tumbler- locks the stump or stud which moves along these slots is riveted to
the bolt, in such manner that, if any pressure be applied in an attempt to withdraw
the bolt, the stump becomes pressed against the edges of the tumblers, and bites or
binds against them. How far their biUng facilitates the picking of a lock will be
shown further on ; but it will suffice here to say, that the movable action given to
the stump in the Hobbs lock transfers the pressure to anothes quarter. The stump 9
is riveted to a peculiarly-shaped piece of metal h p (Jig, 1146), the hole in the centre
of which fits upon a centre or pin in a recess formed at the back of the bolt ; the
piece moves easily on its centre, but is prevented from so doing spontaneously by a
small binding spring. The mode in which this small movable piece takes part in the
action of the lock is as follows: when the proper key is applied in the usual way, the
tumblers are all raised to the proper heights for allowing the stump to pass hori-
zontally through the gating ; but should £here be an attempt made, either by a false
key or by any other instrument, to withdraw the bolt before the tumblers are pro-
perly raised, the stump becomes an obstacle. Meeting with an obstruction to its
passage, the stump turns the piece to which it is attached on its centre, and moves the
arm of the piece p so that it shall come into contact with a stud riveted into the case
of the lock ; and in this position there is a firm resistance against the wlthd^wal of
the bolt. The tumblers are at the same moment released from the pressure of the
stump. There is a dog or lever d, which catches into the top of the bolt, and
thereby serves as an additional security against its being forced back. At k is the
drill- pin on which the pipe of the key works ; and r is a metal piece on which the
tumblers rest when the key is not operating upon them.
Another lock, patented by Mr. Hobbs in 1852, has for its object the absolute
closing of the key-hole during the process of locking. The key does not work or
turn on its own centre, but occupies a small cell or chamber in a revolving cylinder,
which is turned by a fixed handle. The bit of the movable key is entirely separable
f^om the shaft or stem, into which it is screwed, and may be detached by turning
round a small milled headed thumb-screw. The key is placed in the key -hole in
the usual way, but it cannot turn ; its circular movement round the stem as an axis
is prevented by the internal mechanism of the lock ; it is left in the key-hole, and
the stem is detached from it by unscrewing. By turning the handle, Uie key -bit,
which is left in the chamber of the cylinder, u brought into contact with the works
of the lock, so as to shoot and withdraw the bolt. This revolution may take place
whether the bit of the movable key occupy its little cell in the plate or not ; only
with this difference — that if the bit be not in the lock, the plate revolves without
acting upon any of the tumblers } but if the bit be in its place, it raises the tumblers
734 LOCOMOTIVE ENGINES
in the proper iriy fbr ihooliag or withdrawing the bolt It will be nDd«nlood ihU
there u onlj one key-hole, nunely, Ihiil throogh irhieh the diTiwble key it in-
■erted ; the other handle or flied key working through ■ hole in the co»er of the
lock only Jiut Urge enough to receive it, and not being remoTible from the lo^
Aa *oon M (he plate tarna round io far ii to enable the key-bit to urt upon ibe
tamblers, the key-hole becomei entirely closed by the plate itielf. to that the acta*]
locking la elTecled al the *ery time when iJI laeeti to the interior tbr(ni|;h the key-
hole ii cut off. When the bolt hat been nhot, the plate comei Toond to iti original
poailion, it uncorera the key-hole, and eihihiti the key-bit occupying the little cell
lulD which it had been dropped i the atem ii then to be screwed into the bit. and the
latter withdrawn. It Uone consequence of thia amiDgement, that the key haa to be
■cpewed and anacrewed when uaed ; but through tbia arruigement the keyhole
become* a scaled book to one who haa not the right key. Nothing can be mored.
proTided the bit and atem of the key be both led in ; but by leaving in the lock the
former without the latter, the plate can rotate, tbs tnmblera cut be lifted, and the
bolt can be shot.
LOCOMOTIVE ENGINES. The character of tbia work exclndei any ipecial
notice of ■ Eubjecl ao enlirely belonging to a work on Mechanical Engineering, ai
that of locomoliTB enginei. NeTertheleai, alnce ao much haa lately been said and
written on the question of employing coal on our railwa^i inateid of coke, we
are induced to introduce the fullcwiog arrangement, which aecures combuuion
without amoke. It i* known ai Dn-
mcry'a plan. The annexed drawing,
^, 1149, ia aaectioD of a locomotire
engine, uaed on the Chalom Rail-
way. The coal is thrown into tbe
Mde pipee i b, which open below tbe
platform on which the engine-nun
•taoda. Theiepipea condnciihecoal
by their own giiiity to the lower
, level of the tara, where they are
tbnist in the direction of the arrowi
c D, by a hind of comb, or rotating
pin, which in ita rotation around tbe
axle M, force! the coal to ascend the
incline forward by tbe ban.
This then takei place, the coal in
its mde atate (i. e. aa it comes from
the pit) coming from brlow. And*
I itaelf immediately in contact with the
fire, which induces an escape of the
gases, and with the pare air which
permits their combostion to lake
place In the only condition in which
It is posuble, L t. in small Jets, which
&ciliiate the complete oiygcDslioa
of alt the parts.
The gases once ;
of the ODt
The coal I
converted into coke, and Inishet
its passage while barning under
this form : and as the remainder M
the solids, ciadera and slag (or
clinkers), are not abandoned by the fire until after all that it contains of a combustible
natnre has disappeared, all the detrilui (reftiae) and dost, cinden, ashes, &c are de-
pouted on the anrface (•onmef) of the bars in the centre of the fire, where they
would offer an obstrnction similar to that fonnd in ordinary fire-places. If the inientor
had not Uken care to make the bars oscillate fVom the centre by a small movement.
Thoa, when a drop of slag approaches the bars. It is displaced and thrown out
(by the opening of the ban) in small particles. This accessory arrangement appa-
rently poneases great advantages for a locomotive in aafing the trouble of scraping
and cleaning the bars.
Bo if, as in an ordinary fire, coke or anthracite, &c., be burnt, the comhnalion would be
very complete. Air fi-esh from the ash-pan, in passing over the combottiUe, would
be «in»erl«i into carbonic acid, >. t. into a gas which is unfll for further combostion.
Bnt if in tbe place of ooke or anthiaoile, &e. we nse (moke^rodnciog coal, ■■ e. cmb*
LOOKING GLASS. 735
posed of two elements, one nolid, the other gaseous, this result follows. The combus-
tible gases disengaging themselves (iu this case above the combustible) in a state of
ignition, the air which will become vitiated in traversing the first bed of the solid
combustible, will be fonnd unable to effect the combustion of the gases which escape
above the fire, and smoke will make its appearance t. e. the combustion will be in-
complete and imperfect. This is what takes place with combustion of coal in ordinary
fire-places.
There are also other causes which contribute to the imperfection of this result. These
gases in disengaging themselves do not always acquire a temperature sufficiently high
to produce fiame,' and the volume of oombustible gas is almost always too considerable
to allow of its being sufficiently penetrated with oxygen. These are some of the ra-
dical vices which M. Dumery has removed in thus placing the gases at once in the
condition best suited for their combustion. This process is admirable, since, without
any preparation, it allows of coal being burnt with as much facility as coke, and
saves the great expense of converting coal into coke.
LOCUST TREE. A North American tree, the Bobinia pteudaeada. <* It grows
most abundantly in the southern States { but it is pretty generally diffused through
the whole country. It sometimes exceeds four feet in diameter and seventy feet
in height The locust is one of the very few trees planted by the Americans." —
StevensotCs Civil Engineering of North America. This wood is much used for ships*
tree-nails, and is employed for stakes and pales.
LODE (a mining term). A mineral lode, or a mineral vein, is the name given to
a fissure in the crust of the earth which has been filled in with metalliferous matter.
The miner g^ves the same name lode to a fissure filled with quartz, carbonate of lime,
&c., but then he says the lode is not '* mineralised," confining the word mineral to
metalliferous matter.
The term vein has frequently led to the idea that it expresses the condition of
something analogous to the blood vessels of the animal body, to which a lode has not
in the remotest degree, any resemblance. During some primary convulsions, the
crust of the earth has been cracked, these fissures having, of course, some special re-
lation to the direction of the force which produced them. These cracks have during
ages of submergence been filled in, according to some law of polarity with mineral
matter, the character of the lode having generally some special relation to its direc-
tion. See Mining, &c.
LOGWOOD (Bot« de Campkhe, Bois hleu, Fr. ; Blavholz^ Germ.) is the wood of
the Httmatoxylon Campeckianum, a native tree of Central America, grown in Jamaica
since 1715. It was first introduced into England in the reign of Elizabeth, but as it
afforded to the unskilful dyers of her time a fugitive colour, it was not only prohibited
from being used, under severe penalties, but was ordered to be burned wherever found,
by a law passed in the 2drd year of her reign. The same prejudice existed, and the
same law was enacted against indigo. At length, after a century of absurd prohibition,
these two most valuable tinctorial matters, by which all our hats, and the greater part
of our woollen cloths, are dyed, were allowed to be used. The logwood trees grow
from 40 to 50 feet high, the stems are cut into logs of about 3 feet long, the bark and
white sap (alburnum) of which are chipped oiS, the heart or red part only being sent
to England. Chevreul gave the constituents of logwood as volatiu oil, hetmaiin, retin*
OU9 matter, tannin, glutinous matter, acetic acid, sundry salts of lime, with alumina, eilica,
manganese, and iron. The decoction of logwood is of a deep dull red, which is rendered
paler and of a brighter colour by acids. Alkalies give it a purplish or violet colour.
Acetate of lead causes a blue, alum a violet precipitate ; the salts of iron make it a
dark violet blue, gelatine forming a reddish precipitate with it
Old wood, with black bark and with little of the white albumnm, is preferred.
Logwood is denser than water, specific gravity, 1*057, very hard, of a fine compact
grain, and almost indestructible by the atmospheric elements; it has a sweet and
astringent taste, and a peculiar but moffennve smell, and will take a fine polish.
When chipped logwood is for some time exposed to the air, it loses a portion of its
dyeing power. Its decoction absorbs the oxygen of the atmosphere, and then acquires
the property of precipitating with gelatine, which it had not before. The dry extract
of logwood, made from an old decoction, affords only a fugitive ooloar.
For its applications in djeing, see Black Dtb ; Calico Pbintwo ; Dtbiko ; Hat
Dyeing, &c.
The imports of logwood were in
Tom.
Value
1855 -
-
- 30,215 -
•
- £192,795
1856 -
-
- 38,880 -
•
- 264,330
1857 -
-
- 39,568 •
• 236,080
LOOKING GLASS. See Mibrobb.
736 LUBRICATION.
LOOM (Mttier a tiutr, Pr. ; Weba-itiM, Germ.) ii ilie ancient »nd «el1-knoini
machine for weaving cloth b; the deciuaation of & teriei of parallel tbreadi, which
TUD lengthwise, called the warp oruhnin, with other threads thrown trancrenely with
the shuttle, called the woof or weft. See Jacqitabii Loom and Weatinq.
LUBRICANTS, Oieaginoiia or fatty bodiea employed for the parpcae of reducing
the tHelion between two part* of a machine or cama^
LUBRICATION. The lubrication of the wheel and axle of railway carriages ii
effected b; ■ kind of soap, a combination of cocoa-nut oil or palm-oil, or ordinary <,
with loda being the " grease" with which the boxes are filled. The heal prodnoed
by the ft'iction melu the grease, and it flows ont upon the parts in motion Ihrongh ui
opening in the bottom of the box. Heavy machinery, mcb a* pumping engines,
require lenacioiis bodiei sa their lubricanti, while the Gner parts matt tie carefully
oiled with oils as free as possible from any of the fatty acids. Spinning machinery
for eiunple, must be lubricated with the finest oils, or, as is found to be still better,
with those peculiar hydro-carbon compouuds, as pariSne, glycerine, and the like.
The foltowing i* a simple and efficacious plan of lubricating the joints and bearings
of machinery by capillary ■ *"■ ■ "
Fig. 1 1 SO represent* » t'
■ -. — -^ shown by
Fig. IlSl U a plan of
Z*^. 11 53 is a section of
the same. Oil is poured
into the cup, the one end
of a worsted or cotton
thread i« dipped into the
oil, and the other end
passed through the lube.
The capillary attrac-
tion causes the oil to
ascend and pass over the
orifice of Che tube, whence
it gradually descend), and
dropa slower or quicker
according to the length
of the thread or its thick-
ness, until every particle
of oil is drawn over by
this capillary tiphon.
The tube is intended to
bo put into the bearings
of ehafli, &C., and IB made
of any size that may be
wished If oil, or other
liquids, is deaired to be
dropped opon a grind-
stone or other surbce,
this cup can have a handle to it, or be hung fVom the ceiling.
Fig. 11S3. It ia frequently required to stop thecapilUry action when themachinery
is not going ; and this has been effected by means of a tightening screw, which passes
through a screw boss in the cover of the cup, and presses against the internal orifiee
of the lube, preventing the oil trom passing.
Fig, 1154. As when these screw cups are nsed upon beama of engines and moving
bearings, the screw is apt to be tigblened hy the motion ; and dso, as the action
of the screw is nncertain, f^m the workman neglecting to screw it down sufficiently,
it answers best to take out the capillary thread when the lubrication is not required;
and 10 effect this easily, a tin top is fixed to the cup, with a round pipe soldered to it;
this pipe hat a slit in it, like a pencil case, and allows a bolt a to slide easily. In
j!^. 1IS5 the boll is down ; in ^;. 1 158 the bolt, which is a pieceof brass wire, is drawn
up, and thus the flowing of the oil ia checked, la Jig. 1I5G it will be observed, that
the bolt is kept in its place by its bead c, resting in a lateral alii in the pipe, and it
cannot be drawn ont on account of the pin x. One end of the thread ia fastened Ut
the eye bole at the bottom of the bolt, and the other end is tied to a small wire which
crosM* the lower orifiseof the tnbe at d, and which ia shown in plan ^. 1157.
XtrCIFER MATCHEft
737
a the bearingi, ii !
The Mvlng by thU plan, initead of poanDg oil ir
pf S. vhile (he beariugi ire better oiled.
The laviag in labour is coDBiderable where there sre inaDy joints to keep oiled
three or four limes a day ; aod the worktnaa does not, niih thJB apparatus, rnn Iho
risk of being canghl hj- the machinery. To tie on the cotton or worsted thread, pass
a long thread through the eye.faole E of the boit, and then draw the two ends through
the tube bj a fine wire with a hook to it, ooe eod on one side of the crou wire d,
fnd the other end oo the other side. Then pat the cover on, and the bolt in the
position (hown inj^. 1156; when by drawing Ihe two eods of the thread, and tying
them aeroM the wire d, you have the exact leogcb required. Wheti you wish to see
the qoantity of oil remaining in the lubricator, the boll muat be dropped as in^. 1IS5,
and you can then lift the cover a tittle way off, witboot breaking the thread, and re-
plenish wilh oil. The figures in tbe woodcuts are one tbird of Uie fbll aiie.
LUCIFEK MATCHES. The importance of this manufaclnre bas been shown h;
Mr. Tomlingon in a communication made by that geullenun to the journal of the
Society of Arts.
" It has been estimated," he sajs, " that the English and French manufacturers
pf phosphorus are now producing at the rate of 300,000 lbs. of common phosphorus
per annum, nearly the whole of which is consumed in making lucifer matches. In
compounding the emulsion for tipping the matches, the German manutaclnrers make
three pounds of phoEphorns suffice for five or sii millions of matches. If we suppose
only one half of the French and Elnglish annual product of phosphorus to be em-
ployed in making matches, this will give ds ! SO, 000,000,000 of matches as the annual
product consequent on the consumption of one half of the French apd English phos-
phorus. We need not suppose this to be an exaggerated statement, when we coiksider
the daily product of some of our match manufactories. 1 lately had occasion to de-
scribe the processes of a London factory, which produces 2,500,000 matches daily.
For (his purpose, li 3-inch planks are cut up ; each plank produces 30 blocks ; each
block, of the dimensions of 11 inches long, 4^ inches wide, and 3 inches thick, pro-
duces 100 slices, each slice 31 splints, each B[dint 2 matches: thus we have —
14x30x100x31x2 — 3.604.000 matches as tho day's work of a single factory in
I^ndon. At Messrs. Dixon's factory near Manchester, from 6,000,000 to 9,000,000
of matches are produced daily." — Tomluaon,
For tbe rapid manufaclnre of the wooden Epllnts for lucifer matches, a patent we.i
obtained hy Mr. Reuben Partridge, in March, iS4S, He employs a perforated
metallic plate, having a steel face, strengthened by a bell metal back; we Jigi. 1158.
1 1 59. The size of the perforalioni mnst depend on thai of the detired splints, bat they
most be ax close tocher as possible, that there may be a very small blank space be-
tween them, otherwise the plate would afford too great resistance to the passsige of tbii
wood. Ry this construction, the whole area of the block of wood may he com-
pressed laterally into the countersunk openings, and forced through the holes, which
ere slightly tountersunk to favour Ihe entrance and separation of the wooden fibres.
Vol. II. 3 B
738 LUCIFER MATCHES.
Fig, 1 1 58 represents the face of one of tbese plates ; and fig. 1 1 59 is a rectan^lar sectioii
throagh the plate. A oonyenient size of plate ia three inches broad, six inchea long,
and one thick. The mode of pressing is by fixing the back of the plate against a firm
resisting block or bearing* having an aperture equal to the area of the perlbratioai
in the plate, and then placing the end of the piece or pieces of wood in the directioa
of the grain against the fkce of the plate within the area of the perforated portion. A
plunger or lerer or other suitable mechanical agent being then applied to the bade or
reverse end of the piece of wood, it may be forced throagh the perforations in the plate»
being first split as it advances by the catting edges of the holes, and afterwards com-
pressed and driven throagh the perforations in the plate, coming out on the oppoaite
side or back of the plate in the form of a multitude of distinct splints, agreeably to the
shapes and dimensions of the perforations. — NewtotCs Journal^ C. & vol. zxiL 368.
Manufacture of Lucifers. — The first stage in the manufactore of lucifers ia the
cutting the wood, which is done, according to the extent of the manufiu^ry, either by
hand or by machinery. This, as well as the subsequent process of counting and placing
the matches in f^mes, is in itself necessarily free from any inconvenience or evil
consequences ; nor does it appear that the third stage, which consists of melting fiie
sulphur and dipping thf heads of the matches in it, produces any inconvenience*
The foorth, fifth, sixth, and seventh stages comprise the (finding, mnllering, and mix-
ing of the explosive compound; the process of dipping the matches in it, the oounting
and boxing. The dipping, counting, and packing, appear to be, according to Bir. Geist,
the only departments in which the workpeople are in any way affected with peenliar
complaints ; we would even limit the appearance of the jaw disease to those engaged in
dipping ; at least all that we have examined on the sobjeet were unanimous as to the &ct
that dippers only were attacked. There is a certain degree of secrecy observed relative
to the proportions of the composition ; and the mixture of the materials is gene-
rally performed by the proprietor of the manui^M^ry, or by a confidential workman*
Chlorate of potash is considered an essential ingredient in England ; but in the maiiu<^
Victories at Niimberg it has not been employed for a number of ^ears, as its explosive
properties much endangered the safety of the buildings and the limbs of the workmen.
The composition used in Niimberg consists of one-third of phosphorus, of gum
arabic (which is eschewed by English manufacturers on account of its hygrometric
property), of water, and of colouring matter, for which either minium or Prussian blue
is employed. If ignition be required without a flame, the quantity of phosphorus is
diminished, or nitrate of lead is added. The mixing is conducted in a water-bath ; and
during this process, and as long as the phosphorus is being groond or *'mullered,"
copioas fumes are evolved. The dipping is performed in the following manner : — ^The
melted composition is spread upon a board covered with cloth or leather, and the work-
man dips the two ends of the matches alternately that are fixed in the frame ; and as
this is done with great rapidity, the disengagement of fumes is very considerable, and
the more liable to- be injurious, as they are evolved in a very concentrated form dose
to the face of the workman. This department is generally left to a single wo/kman ;
and the average number that he can dip in an hour, supposing each frame to hold 3,000
matches, would be 1,000,000.
As the matches l^ve been dipped, they require to be dried. This is generally
done in the room in which the former process is carried on ; and as a temperature m
from 80^ to 90^ Fahr. is necessary, the greatest quantity of fumes is evolved at this
stage. When the matches are dried, the fhunes are removed from the drying room,
and the lucifers are now ready to be counted out into boxes. As this is done with
great rapidity, they frequently take fire, and, although instantly extinguished in the
sawdust or the water which is at hand, the occurrence g^ves rise to an additional and
frequent evolution of fumes.
According to Dr. R. Boettger, in Annalen der ChenUe v»d Pharmacies voL zlviL
p. 334, the best composition for lucifer matches is
Phosphorus - - -4 parts [ Ked ochre, or red lead 5 parts
Nitre - - - - 10 „ Smalt - - - 2 „
Fine glue - • - 6 „
Convert the glue with a little water by a gentle heat into a smooth jelly, put it into a
slightly warm porcelain mortar to liquefy ; rub the phosphorus down through this gela-
tine at a temperature of about 140° or 150° Fahr. ; add the nitre, then the red powder,
and lastly the smalt, till the whole forms a uniform paste. To make writing-paper
matches, which burn with a bright flame and diffuse an agreeable odour, moisten each
side of the paper with tincture of benzoin, dry it, cat it into slips, and smear one of
their ends with a little of the above paste by means of a hair pencil. On rubbing the
said end after it is dry against a rough surface the paper will take fire, without the
intervention of sulphur.
To form lucifer wood matches, that act without sulphur, melt in a flat-bottomed
LUTE. 789
tin pan as maeh white irax as -will stand one-tentn of an inch deep ; take a bundle of
wooden matches tree from resin, mb their ends against a red hot iron plate till the wood
be slightly charred ; dip them now in the melU^ wax for a moment, idiake them well
on taUng them out, and finally dip them separately in the above Tiseid paste* When
dry, they will kindle readily by friction.
A ** Safity Ludfer Afatch,** as it is called, has been mannfectared in Sweden. A
patent was obtiuned in that country by Messrs. Bryant and May, for this match. Its
peculiarity consists in the division of tne combustible ingredients of the lucifer between
the match and the friction paper. In the ordinary lucifer, the phosphorus, sulphur,
and chlorate of potash or nitre, are all together on the match, which ignites when
rubbed against any rough substance. In the Swedish matches these materials are so
divided that the phosphorus is placed on the sand-paper, whilst the sulphur and a
mininum amount of chlorate or nitrate of potash is placed on the match. In virtue of
this arrangement it is only when the phosphorised sand-paper and the sdlphurised
match come in contact with each other that the ignition occurs. Neither match nor
sand-paper, singly, takes fire by moderate friction against a rough snrfkce.
The composition of lucifer matches varies greatly, as it regards the proportions of
the materials employed. In principle they are, however, as we have described them
above ; everything depending on the ignition of the phosphorus, and the perfection of a
lucifer match is in tipping the match with a composition which will ignite quietly upon
attrition against any rough snrfkce, but which is not liable to ignition by such pres-
sure as it may be subject^ to under the ordinary condition of keeping in closed boxes.
The preparation of lucifer matches has been attended with much human suffering.
Every person engaged in a ihctory of this kind is more or less exposed to the fumes
of phosphorus, and this exposure produces a disease which has been thus described by
Mr. Harrison, in the Quarterly Journal of Medical Science. — ** This disease,'* he says,
" is of so insidious a nature that it is at first supposed to be common toothache, and a
most serious disease of the jaw is produced before the patient is fully aware of his con-
dition. The disease g^radually creeps on, until the sufferer becomes a miserable and
loathsome object, spending the best period of his life in the wards of a public hospitaL
Many patients have died of the disease ; many, unable to open their jaws, have lingered
with carious and necrosed bones ; others have suffered dreadful mutilations from
surgical operations, considering themselves happy to escape with the loss of the greater
portion of the lower jaw."
By the introduction of an amorphous phosphorus discovered by M. Schrotter, which
is in nearly all respects unlike the ordinary phosphorus, but which answers exceed-
ingly well for the manufacture of lucifer matches, this disease is prevented, the manu-
factory is rendered more healthy, and the boxes of matches themselves less dangerous.
See Phosphorus. In 1857 our imports and exports were—
/mporte— Lucifers— Wood, No. • • 155,153 - -^£29,091
„ Vesta of Wax - - 17,395,210 - * 1450
j&jporte—Lucifers— Wood (Cubic Feet) - 10,628 • • £1993
„ Vesta of Wax, No. - 6.604,480 - - 47
LUMACHELLE, or Fire Marble. This is a dark brown shelly marble, having
brilliant fire or chatoyant reflections from within. — See Marble.
LUNAB CAUSTIC. A name for nitrate of silver, when fused and run into
cylindrical moulds.
LU PI NINE, is a substance of a gummy appearance, so named by M. Cussola,
because it was obtained firom Lupines — C. G. W.
LUPULINE, from ffumulus Lupvlus; is the peculiar bitter aromatic principle of
the hop. See Beer.
LUSTRING, sometimes spelled and pronounced Lutestring ; a peculiar shining silk.
LUTE (from lutum, clay ; Xuf, Fr.; KittCt Beschldgey Germ.) is a pasty or loamy
matter employed to close the joints of chemical apparatus, or to coat their surfaces, and
protect them from the direct action of flame. Lutes differ according to the nature of
the vapours which they are destined to confine, and the degree of heat which they are
to be exposed to.
1. Lute of linseed meal, made into a soft plastic dough with water, and immediately
applied pretty thick to junctions of glass, or stone-ware, makes them perfectly tight,
hardens speedily, resists acid and ammoniacal vapours, as also a moderate degree of
heat It becomes stronger when the meal is kneaded with milk, lime-water, or solu-
tion of glue, and is the best lute for fluo-silicic acid.
2. Lute of thick gum-water, kneaded with clay, and iron filings, serves well for per-
manent junctions, as it becomes extremely solid.
3. By softening in water a piece of thick brown-paper, kneading it, first with rye-
fiour paste, and then with some potter's clay, till it acquire the proper consistence, a
lute is formed which does not r^ily crack or scale on.
740 LYNX-
4. Lute, coDUsdng of a strong solution of glae kneaded into a dongh with netr
slaked lime, is a powerful cement, and with the addition of white of egg forms Uie
iut (fane; — a composition adapted to mend broken vessels of porcelain and stone- ware.
5. Skim-milk cheese, boiled for some time in water, and then triturated into paste
with fresh-slaked lime, forms also a good lute.
6. Calcined gypsum, diffused through milk, solution of glue, or starch, is a valuable
lute in many cases.
7. A lute made with linseed, melted caoutchouc, and pipe-clay, incorporated into a
smooth dough, may be kept long soft when covered in a cellar, and serves admirably
to confine acid vapours. Aa it does not harden, it may therefore be applied and taken
off as often as we please,
8. Caoutchouc itself* after being melted in a spoon, may be advantageously used for
securing joints against chlorine and acid vapours, in emergencies when nothing else
would b^effectual, or we may use 1 part of caoutchouc dissolved in two parts of hot
linseed-oil, and worked up with pipe-clay (3 parts) into a plastic mass. It bears the
heat at which sulphuric acid boils.
9. The best lute for joining crucibles inverted into each other, is a dough made with
a mixture of fresh fire-clay, and ground fire-bricks, worked with water. That cement,
if made with solution of borax, answers still better, upon some occasions, as it becomea
a compact vitreous mass in the fire,
LUTEOLINE, is the colouring principle of the weld {Reseda luieoJd), a slender
plant growing to the height of about three feet, and cultivated for the use of dyers.
When ripe it is cut and dried.
Chevreul was the first to separate the luteoUne ; it is extracted from the weld by
boiling water, and when this solution is concentrated and allowed to cool, the
Inteoline separates ; it is then collected, dried, and submitted to sublimation, when
it is condensed in yellow needles.
It is valued for its durability, and is used as a yellow dye, on cottons principally,
and also on silks, but is little used at present It was formerly used by paper-hanging
manufacturers, to form a yellow pigment, but has been entirely superseded for that
purpose, by quercitron bark and Persian berries. It unites with acids and alkalies, the
former making the colour paler, and the latter heightening the colour. The compound
which it forms with potash is of a golden colour, becoming greenish when exposed to
the air, by absorption of oxygen, and at length becomes red.
It forms yellow compounds with alum, protochloride of tin, and acetate of lead ;
with the salts of iron it produces a blackish grey precipitate, and with sulphate of
copper a greenish brown precipitate.
It is readily soluble in alcohol and ether, but sparingly so in water. — ^H. K. B.
LUTIDINE, C"H»N. A Tolatile nitryle base, discovered by Anderson in
bone oil. It has also been found in shale naphtha, coal naphtha, and in crude
chinoline. — C. O. W.
LYCOPODIUM CLAVATUM. The seeds of the lycopodium ripen in Sep-
tember. They are employed, on account of their great combustibility, in theatres to
imitate the sudden flash of lightning, by throwing a quantity of them from a powder
pufil or bellows, across the flame of a candle.
LYDIAN STONE, Touchstone, or BasaniU. A flinty variety of jasper, used on
account of its hardness, fine texture, and velvet black colour, for trying the purity of
the precious metals. The amount of alloy is indicated by the colour left on the st<Nie
after the metal has been rubbed across it
LYNX. — An animal producing a favourite fur of a greyish white, with dark spota.
EKD OF THE SECOND VOLUME.
LONDON;
PRINTED BV tPOTTItWOODS AND CO,
MBW-aTSEBT BQUAtB.
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