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LIBRARY
THE UNIVERSITY
OF CALIFORNIA
SANTA BARBARA
PRESENTED BY
Wi 1 bur R, Jacobs
UCSB
^ I I''. >- G 1 >• K .
L-Kf-
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a
THE
USEFUL ARTS,
CONSroERED IN CONNEXION
APPLICATIONS OF SCIENCE
WITH NUMEROUS ENGRAVINGS.
BY JACOB BIGELOW, M.D.
PROFESSOR OF MATERIA MEDICA IN HARVARD UNIVERSITY, AUTHOR OF
' THE ELEMENTS OF TECHNOLOGY,' ETC. ETC.
IN TWO VOLUMES.
VOL. n
N E W Y O R K :
HARPER & BROTHERS, PUBLISHERS,
329 & 331 PEARL STREET,
FRANKLIN SQUARE.
1863.
Entered according to Act of ('ongress, in the year 1840, by
Marsh, Capkn, Lyon, and Webb,
in the Clerk's Office of the District Court of Massachusetts.
CONTENTS
CUAPTER XIV.
ARTS OF LOCOMOTION.
Motion of Animals ; Inertia ; Aids to Locomotion
Wheel Carriages : — Wheels ; Rollers ; Size of
Wheels ; Line of Traction ; Broad Wheels ; Form
of Wheels ; Axletrees ; Springs ; Attaching of
Horses. Highways: — Roads; Pavements; Wood-
en Pavements; McAdam Roads. Bridges: —
Wooden Bridges ; Stone Bridges ; Cast-Iron
Bridges ; Suspension Bridges ; Floating Bridges.
Rail Roads : — Edge Rail-way ; Tram Road ; Single
Rail ; Passings, or Sidings ; Turn Plate ; Curves ;
Propelling Power ; Locomotive Engines ; Station-
ary Engines. Canals : — Embankments ; Aque-
ducts ; Tunnels ; Gates and Weirs ; Locks ;
Boats ; Size of Canals. Sailing : — Form of a Ship;
Keel and Rudder ; Effect of the Wind ; Stability
of a Ship ; Steam Boats ; Steam Ships. Diving
Bell : — Submarine Navigation. Aerostation : — Bal-
oon ; Parachute, 9
CONTENTS.
CHAPTER XV,
ELEMENTS 01 MACHINERY.
Machines ; Motion. Rotary, or Circular Motion :— -
Band Wheels ; Rag Wheels ; Toothed Wheels ;
Spiral Gear ; Bevel Gear ; Crown Wheels ; Uni-
versal Joint ; Perpetual Screw ; Brush Wheels ;
Ratchet Wheel ; Distant Rotary Motion ; Change
of Velocity ; Fusee. Alternate, or Reciprocating
Motion : — Cams ; Crank ; Parallel Motion ; Sun
andPlanet Wheel ; Inclined Wheel ; Epicycloidal
Wheel ; Rack and Segment ; Rack and Pinion ;
Belt and Segment ; Scapements. Continued Rec-
tilinear Motion : — Band ; Rack ; ^Universal Lever ;
Screw ; Change of Direction ; Toggle Joint. Of
Engaging and Disengaging Machinery. Of Equal-
izing Motion : — Governor ; Fly Wheel. Friction.
Remarks, . . 5^
CHAPTER XVI.
OF THE MOVING FORCES USED IN THE AR1&.
Sources of Power ; Vehicles of Power, Animal Pow-
er : — Men ; Horses. Water Power : — Overshot
Wheel ; Chain Wheel ; Undershot Wheel ; Back
Water ; Besant's Wheel ; Lambert's Wheel ;
Breast Wheel ; Horizontal Wheel ; Barker's Mill.
Wind Power : — ^Vertical Windmill ; Adjustment of
Sails ; Horizontal Windmill. Steam Power : —
Steam; Applications of Steam ; By Condensation ;
By Generation ; By Expansion ; The Steam En-
gine ; Boiler ; Appendages ; Engine ; Noncon-
densing Engine ; Condensing Engines ; Descrip-
tion ; Expansion Engines ; Condenser; Valves ;
Pistons ; Parallel Motion ; Locomotive Engine ;
CONTENTS. 5
Power of the Steam Engine ; Projected Improve-
ments ; Rotative Engines ; Use of Steam at High
Temperatures ; Use of Vapors of Low Tempera-
ture ; Gas Engines ; Steam Carriages ; Steam
Gun. Gunpowder : — Manufacture ; Detonation ;
Force ; Properties of a Gun : Blasting. Magnet-
ic Engines, 81
CHAPTER XVII.
ARTS OF CONVEYING WATER.
Of Conducting Water : — Aqueducts ; Water Pipes 5
Friction of Pipes ; Obstruction of Pipes ; Syphon.
Of Raising Water : — Scoop Wheel ; Persian
Wheel ; Noria ; Ijj^e Pump ; Hydreole ; Archi
medes' Screw ; Spiral Pump ; Centrifugal Pump ;
~ Common Pumps ; Forcing Pump ; Plunger Pump ;
De La Hire's Pump ; Hydrostatic Press ; Lifting
Pump ; Bag Pump ; Double-acting Pump ; Rol-
ling Pump ; Eccentric Pump ; Arrangement of
Pipes ; Chain Pump ; Schemnitz Vessels, or Hun-
garian Machine ; Hero's Fountain ; Atmospheric
Machines ; Hydraulic Ram. Of Projecting Water :
—Fountains ; Fire Engines ; Throwing Wheel, . 135
CHAPTER XVIII.
ARTS OF COMBINING FLEXIBLE FIBRES.
Theory of Twisting ; Rope Making ; Hemp Spin-
ning. Cotton Manufacture : — Elementary Inven-
tions ; Batting ; Carding ; Drawing ; Roving ;
Spinning ; Mule Spinning ; Vv^arping ; Dressing ;
Weaving ; Twilling ; Double Weaving ; Cross
Weaving ; Lace ; Carpeting ; Tapestry ; Velvets
Linens. Woollens. Felting. Paper Making.
Bookbinding, . . 164
1*
CONTENTS,
CHAPTER XIX.
ARTS OF HOROLOGY.
Sun Dial ; Clepsydra ; Water Clock ; Clock Work ;
Maintaining Power ; Regulating Movement ; Pen-
dulum ; Balance ; Scapement ; Description of a
Clock ; Striking Part ; Description of a Watch, 187
CHAPTER XX.
ARTS OF METALLURGY.
Extraction of Metals ; Assaying ; Alloys. Gold : —
Extraction ; Cupellation ; Partif% ; Cementation ;
Alloy ; Working ; Gold Beating ; Gilding on Met-
als ; Gold Wire. Silver : — Extraction ; Working •
Coining ; Plating. Copper : — Extraction ; Work-
ing. Brass : — Manufacture ; Buttons ; Pins ;
Bronze. Lead : — Extraction ; Manufacture ; Sheet
Lead ; Lead Pipes ; Leaden Shot. Tin : — Block
Tin ; Tin Plates ; Silvering of Mirrors. Iron : —
Smelting ; Crude Iron ; Casting ; Malleable Iron ;
Forging ; Rolling and Slitting ; Wire Drawing ;
Nail Making ; Gun Making. Steel : — Alloys of
Steel ; Case Hardening ; Tempering ; Cutlery, 208
CHAPTER XXI.
ARTS OF VITRIFICATION.
Glass ; Materials ; Crown Glass ; Fritting ; Melt-
ing ; Blowing ; Annealing ; Broad Glass ; Flint
Glass ; Bottle Glass ; Cylinder Glass ; Plate
Glass ; Moulding ; Pressing ; Cutting ; Stained
Glass ; Enamelling ; Artificial Gems ; Devitrifica-
CONTENTS. 7
tion ; Reaumur's Porcelain ; Crystallo-Ceramie ;
Glass Thread ; Remarks, 247
CHAPTER XXII.
ARTS OF INDURATION BY HEAT.
Bricks ; Pressed Bricks ; Tiles ; Terra Cotta ; Cru-
cibles ; Pottery ; Operations ; Stone Ware ;
White Ware ; Throwing ; Pressing ; Casting ;
Burning ; Printing ; Glazing ; China Ware ; Eu-
ropean Porcelain ; Etruscan Vases, .... 262
APPENDIX.
Artesian Wells. Mines. Depth of Mines. Canals
in the United States. Rail-Ways in the United
States. Manufacture of Maple Sugar. Manufac-
ture of Beet Sugar. Voltaic Electrical Engraving.
Photogenic Drawing, 275
Glossary, . . ... 369
Index, . , . 375
THE USEFUL ARTS
CHAPTER XIV.
ARTS OF LOCOAIOTIOX.
Motioa of Animals, Inertia, Aids to Locomotion, Wheel Carnages^
Wheels, Rollers, Size of Wheels, Line of Traction, Broad W^heels,
Form of Wheels, Axletrees, Springs, Attaching of Horses. High-
ways, Roads, Pavements, Wooden Pavements,* McAdam Roads.
Bridges, 1, ^V'ooden Bridges, 2, Stone Bridges, 3, Cast-Iron Bridges,
4, Suspension Bridges, 5, Floathig Bridges. Rail Roads, Edge
Rail-way, Tram Road, Single Rail, Passings, or Sidings, Turn
Plate, Curves, Propelling Power, Locomotive Engines, Stationary
Engines- Canals, Embankments, Aqueducts, Tunnels, Gates and
Weirs, Locks, Boats, Size of Canals. Sailing, Form of a Ship,
Keel and Rudder, Effect of the Wind, Stability of a Ship, Steam
Boats, Steam Ships. Diving Bell, Submarine Navigation. Aeros-
tation, Balloon, Parachute.
Animals, of the more perfect kinds, possess the power
of shifting their place, at will, which power they exercise,
both in transporting their own bodies, and in conv^eying
other masses of matter. The chief obstacles, which op-
pose locomotion or change of place, are, gravity and fric-
tion, the last of which is, in most cases, a consequence
of the first. Gravity confines all terrestrial bodies against
the surface of the earth, with a force proportionate to the
quantity of matter which composes them. Before they
can be removed from one spot of this surface, to another,
Df equal height, they must either be lifted from the ground,
igainst the force of gravity, or carried, horizontally, along
rhe surface, resisting with a degree of friction, which in-
ireases with their weight. Most kinds of mechanism,
both natural and artificial, which assist locomotion, are
arrangements for obviating the effects of gravity and fric-
lion.
10 ARTS OF LOCOMOTION.
J\Iotio7i of Animals. — Animals, that walk, obviate fric-
tion, by substituting points of their bodies, instead of large
surfaces ; and upon these points they turn, as upon cen-
tres, for the length of each step, raising themselves wholly,
or partly, from the ground, in successive arcs, instead of
drawing themselves along the surface. The hne of arcs,
which the centre of gravity describes, is converted into
an easy, or undulating hne, by the compound action of the
different joints. As the feet move in separate hnes, the
body has, also, a lateral, vibratory motion. A man, in
walking, puts down one foot, before the other is raised,
but not in running. Quadrupeds, in walking, have three
feet upon the ground, for most of the time ; in trotting,
only two. Animals, which w^alk against gravity, as the
common fly, the tree toad, &c., support themselves by
suction, using cavities on the under side of their feet,
which they enlarge, at pleasure, till the pressure of the at-
mosphere causes them to adhere. In other respects, their
locomotion is effected like that of other walking animals.
Birds perform the motion of flying, by striking the air,
with the broad surface of their wings, in a downward, and
backward, direction, thus propelling the body upward, and
forward. After each stroke, the wings are contracted,
or slightly turned, to lessen their resistance to the atmos-
phere, then raised, and spread anew. The downward
stroke, also, being more sudden than the upward, is more
resisted by the atmosphere. The tail of birds serves as
a rudder, to direct the course upward, or downward.
When a bird sails in the air, w^ithout moving the wings, it
is done, in some cases, by the velocity previously acquired,
and an oblique direction of the wings, upward ; in others,
by a gradual descent, with the wings slightly turned in an
oblique direction, downward. Fishes, in swimming for-
ward, are propelled chiefly by strokes of the tail, the ex-
tremity of which, being bent into an oblique position, pro-
pels the body forward, and laterally, at the same time. The
lateral motion is corrected by the next stroke, in the op-
posite direction, while the forward course continues. The
fins serve, partly, to assist in swimming, but, chiefly, to
balance the body, or keep it upright ; for the centre of
INERTIA. 11
gravity being nearest the back, a fish turns over, when it
is dead, or disabled.* Some other aquatic animals, as
leeches, swim with a sinuous, or undulating, motion of the
body, in which several parts, at once, are made to act
obliquely, against the water. Serpents, in like manner,
advance, by means of the winding, or serpentine, direction
which they give to their bodies, and by which a succes-
sion of oblique forces is brought to act against the ground.
Sir Everard Home is of opinion, that serpents use their
ribs, in the manner of legs, and propel the body forwards,
by bringing the plates, on the under surface of the body,
to act, successively, like feet, against the ground. f Some
worms and larvas, of slow motion, extend a part of their
body forwards, and draw up the rest to overtake it ; some
performing this motion, in a direct line, others, in curves.
When land animals swim in water, they are supported,
because their whole weight, with the lungs expanded with
air, is less than that of an equal bulk of water. The head,
however, or a part of it, must be kept above water, to
enable the animal to breathe ; and to effect this, and also
to make progress in the water, the hmbs are exerted, in
successive impulses, against the fluid. Quadrupeds and
birds swim with less effort than man, because the weight
of the head, which is carried above water, is, in them, a
smaller proportional part of the whole, than it is in man.
Inertia. — In consequence of the action of gravity upon
bodies, their inertia becomes a greater obstacle to loco-
motion than it would otherwise be. Every body tends,
by its inertia, to preserve a state of rest, if it is still, and
of uniform rectilinear motion, if it is not still. Changes,
therefore, not only from rest to motion, but also changes
* The swimming bladder, which exists in most fishes, though not in
all, is supposed to have an agency in adapting the specific gravity of
the fish to the particular depth, in which it resides. The power of the
animal to rise or sink, by altering the dimensions of this organ, haa
been, with some reason, disputed.
t Lectures on Comparative Anatomy, vol. i. p. 116, &c. Sir E
Home deduces this fact from the anatomy of the animal, and from the
movements which he perceived, in suffering a large coluber to crawl
over his hand. The ribs appeared to be raised, spread, carried for
ward, depressed, and pushed backward, successively.
12 ARTS OF LOCOMOTION.
of direction, and changes of speed, are resisted by the
force of inertia. Bodies moving upon the earth's surface
are obhged, by their gravity, to accommodate their mo-
tions to the irregularities of this surface, and, consequent-
ly, to change, often, both their direction and velocity The
inertia thus becomes a continual source of expenditure of
power, although it would not be so, if bodies moved at a
uniform rate, and in a straight course.
Aids to Locomotion. — All animals are provided, by
Nature, with organs of locomotion best adapted to their
structure and situation ; and it is probable that no animal,
man not being excepted, can exert his strength more ad-
vantageously, by any other than the natural mode, in moving
himself over the common surface of the ground.* Thus
walking-cars, velocipedes, &c., although they m.ay enable
a man to increase his velocity in favorable situations, for a
short time, yet they actually require an increased expen-
diture of power, for the purpose of transporting the ma-
chine made use of, in addition to the weight of the body.
When, however, a great additional load is to be transport-
ed with the body, a man, or animal, may derive much
assistance from mechanical arrangements.
Wheel Carriages. — For moving weights over the com
mon ground, with its ordinary asperities and inequalities of
substance and structure, no piece of inert mechanism is
so favorably adapted, as the wheel-carriage. It was in-
troduced into use, in very early ages, as affording a facil-
ity for the carrying of heavy loads, and, finally, for trans
porting man himself; not by his own powers, but by the
strength of other animals, which he had subjugated to his
use. Chariots were used in war, and wagons in agricul-
ture, at a very remote period.
Wheels. — The mechanical action of wheels, applied to
locomotive carriages, is twofold. They diminish friction,
and, also, surmount obstacles, or inequalities, of the road,
with more advantage than bodies of any other form, in
their place, could do. The friction is diminished, by
transferring it from the surface of the ground to the cen-
* This remark, of course, does not apply to situations in which fric-
tion is obviated, as upon water, ice, rail-roads, &c.
ROLLERS. SIZE OF WHEELS 13
tre of the wheel, or rather to the place of contact, between
the axletree and the box of the wheel. So that it is les-
sened, by the mechanical advantage of the lever, in the
proportion, which the diameter of the axletre>3 bears to the
diameter of the wheel. The rubbing surfaces, also,
beiig kept polished, and smeared with some unctuous
substance, are in the best possible condition to resist
friction.
In like manner, the common obstacles, that present
themselves in the public roads, are surmounted by a wheel,
with pecuhar facility. As soon as the wheel strikes
against a stone, or similar hard body, it is converted into
a lever, for lifting the load over the resisting object. If
an obstacle, eight or ten inches in height, were presented
to the body of a carriage, unprovided with wheels,- it
would stop its progress, or subject it to such violence as
would endanger its safety. But, by the action of a wheel,
the load is lifted, and its centre of gravity passes over, in
the direction of an easy arc, the obstacle furnishing the
fulcrum, on which the lever acts.
Rollers. ^R^oWers, placed under a heavy body, diminish
the friction in a greater degree than wheels, provided
they are true spheres, or cylinders, without any axis, on
which they are constrained to move. If the rollers be
perfectly elastic, and, also, the plane upon which they
move, there will be no sliding friction, whatever ; whereas
the wheel always rubs at its axis. But an offset for this
advantage is found in the circumstance, that the wheel
maintains its relative place, in regard to the load, while the
roller constantly falls behind, and is obhged to be taken
up and replaced, at an expense of power. A cyhndrical
roller, likewise, occasions friction, whenever its path de-
viates, in the least, from a straight line.
Size of Wheels. — The mechanical advantages of a
wheel are proportionate to its size ; and the larger it is,
the more effectually does it diminish the ordinary resist-
ances. A large wheel will surmount stones, and similar
obstacles, better than a small one ; since the arm of the
iever, on which the force acts, is longer, and the curve,
described by the centre of the load, is the arc of a iar-
II. 2 XII.
14 ARTS OF LOCOMOTION.
ger circle, and, of course, the ascent is more gradual and
easy.*
A. further advantage is derived from the circumstance,
that, in passing over holes, ruts, or excavations, a large
wheel sinks less than a small one, and, consequently, occa-
sions less jolting, and expenditure of power. The \v«ar,
also, of small wheels, exceeds that of larger ones ; for, if
we suppose a wheel to be three feet in diameter, it will
turn round twice, while a wheel, six feet in diameter, turns
round once. Of course, its tire will come twice as often
in contact with the ground, and its spokes will twice as
often have to support the weight of the load. So, that,
by calculation, it should last but half the length of time.
On these accounts, it would be advantageous to aug-
ment the diameter of wheels to a great extent, were it not
for certain practical limits, which it is not found useful to
exceed. One of these is found in the nature of the ma-
terials, which we are obliged to use, and which, if em-
ployed to make wheels of great size, at the same time
preserving the requisite strength, would render them cum-
bersome, and too heavy for use.f Another reason, for
regulating the size of wheels by a limited standard, arises
from the relative size of the animals, commonly employed
for draught. A wheel should seldom be of such dimen-
sions, that its centre would exceed, in height, the breast of
the horse, or other animal, by which it is drawn ; because,
if this were the case, the horse would draw obhquely
downward, as well as forward, and expend a part of his
strength in acting against the ground.
Line of Traction. — In practice, it is even found neces-
sary, to place the point of draught, or centre of the wheels,
lower than the middle of the horse's breast, for various
reasons. 1. The shape of the animal's shoulders requires
this direction. 2. The horse exerts a greater force, in
proportion, as the line of draught passes near the fulcrum,
* If the plane, on which a carriage moves, and the line of draught be
both horizontal, the advantage, for surmounting an immovable obstacle
of a given height, is as the square root of the radius of the wheel. — Se«
Flayfair's Outlines of JVatural Philosophy, vol. i. p. 103.
t See the article. Limit of Bulk, p. 48
BROAD WHEELS. 15
which is in his hind feet. 3. If a horse draws obliquely
upward, a part of his force is employed in lessening the
pressure on the ground, and, to answer this purpose most
effectually, it has been remarked, that the inclination of
the traces, or shafts, ought to be the same with that of a
road, upon which the carriage would just descend by its
own weight.* According to Dr. Gregory, a power, which
moves a sliding body along a horizontal plane, acts with
the greatest advantage, as far as friction is concerned,
when the line of direction makes an angle of about eigh-
teen and a half degrees with the plane. f M. Deparcieux
states, from experiments with carriages, that the angle,
made by the trace with a horizontal line, should be one of
fourteen or fifteen degrees. 4. Another reason, for in-
clining the hne of draught, is, that a horse depresses his
body, in proportion to the force he is obliged to exert, in
order that he may bring his own weight to act more advan-
tageously upon the load. M. Deparcieux has demon-
strated, that animals draw through the medium of their
weight, in all our common vehicles ; and this fact becomes
obvious, when we consider, that if a horse had no weight,
he would be unable to draw, but would simply be raised
on his hind feet, by any exertion to advance, while in his
harness.
In the foregoing considerations, it is necessary to re-
collect, that the conditions, which enable a horse to exert
his greatest force, are not those which promote his greatest
velocity, and that the means of increasing his speed are
obtained, as in other cases, by the sacrifice of power.
When there are four wheels, the line of draught ought
to be directed to a point between the two axletrees, or,
rather, to a point directly under the centre of gravity of
the load ; and such a line should always pass above the
axle of the fore wheels.
Broad Wheels. — Much controversy has existed in re-
gard to the comparative utility of wheels having a broad,
or a narrow, circumference. The disadvantages of broad
wheels are, that they are* heavier than narrow ones, that
* Young's Natural Philosophy, vol. i. p. 216.
t Treatise on Mechanics, vol ii p. 18.
16 ARTS OF LOCOMOTION
they are more expensive, and that they include in their
path a greater number of stones, or projecting obstacles.
Their advantages are, that they pass more easily over
ruts and holes, and that^ in soft and sandy roads, they sink
to a smaller depth.* But the great benefit which results
from broad wheels is of an indirect kind, and arises from
the improvement of the roads, which takes place under
their use. They tend to prevent deep and narrow ruts,
and act as rollers, in levelling the surface.
Form of Wheels. — If roads w^ere, in all cases, level and
smooth, wheels should be made exactly cylindrical, or
with all their spokes parallel to the same plane. But,
since the unequal surface of most roads exposes carriages
to frequent and sudden changes of position, it is found
advantageous to make the wheels a litde conical, or, as it
is commonly termed, dishing, so that the spokes may all
diverge, with their extremities from the carriage. In this
case, whenever the carriage is thrown into an inclined
position, and the centre of gravity shifted towards one
wheel, the spokes on the under side of that wheel, become
more nearly vertical, and are in a more advantageous
position to sustain the pressure. This w^ill be seen in
Fig. 94, on the opposite page. In muddy roads, there
is a convenience attending the dished wheel, in having its
circumference further from the body of the carriage, than
that of a straight wheel, upon the same hubb,f would be.
Some disadvantages, at the same time, attend upon this
form of the w^ieel, the principal of which is, the increase
of friction which it occasions. A conical wheel, if left to
itself, tends to travel in a circle, round a point, where the
apex of the cone would be situated. If it is obliged to
advance in a straight line, it has a degree of lateral motion
and friction, which increases in proportion as it deviates
from the cyhndrical form. In common cases, a slight
* The latter advantage, however, is of a more equivocal kind than
appears at first view ; for although they sink less deeply, they displace
more earth in sinking to the same depth. Still, however, the advan-
tage, upon calculation, remains on the side of the broad wheel.
t This word, instead of ?iai'C, is so generally used in this country, tha^
It would be a useless refinement to avoid it. The same is true of tlw
woTd factory for manufactory, and also of many mechanical terms.
AXLETREES SPRINGS, ETC. 17
degree of the dishing form is best, but it should never be
carried to such an extent, as to create much friction, or
endanger the bending of the spokes.
In the annexed figure, (94,) A represents the cyhndri-
cal, and B the dished, form of the wheel.
Fis. 94.
Axletrees. — When wheels are perfectly upright, the
ends of the axles should be cylindrical ; but, in dished
wheels, they are made conical, and inclined downward, so
as to make their under surface horizontal. In this case,
the wheels spread most at top, and the lower spokes are
most nearly vertical. The ends of the axletree are often
inclined a httle forward, which arrangement causes the
wheels to run inward, and prevents them from pressing
on the hnch-pin. The friction, however, is increased.
In some locomotive carriages, the axle is fixed to both
wheels, and turns with them. This mode of connexion
causes great strain and friction, whenever the path is in
any other than a straight hue, from the necessity, which
IS produced, that the wheels should keep pace with each
other, in their revolutions.
Springs. — The effect of suspending a carriage on
springs is, to equalize the motion, by causing every change
to be- more gradually communicated to it, and to obviate
shocks, by converting percussion into pressure.. Springs
are not only useful for the convenience of passengers, but
they also diminish the labor of draught ; for, whenever a
wheel strikes a stone, it rises against the pressure of the
spring, in many cases, without materially disturbing the
load ; whereas, without the spring, the load, or a part of
it, must rise with every jolt of the wheel, and will resist
this change of place, with a degree o^ inertia proportionate
to the weight and the suddenness of the percussion.
IS
ARTS OF LOCOMOTION.
Hence, springs are highly useful, in baggage wagons, ard
other vehicles, used for heavy transportation.*
Attaching of Horses. — Horses draw most advantage •
ously, when they are either single, or harnessed abreast
of each other. When two horses draw side by side, they
are equally near to the load, and have the same line of
traction. If their traces are attached, as is frequently done,
to hooks on the ends of a crossbar, which, in its turn, is
connected to the carriage by a staple, projecting behind,
a compensation will be thus made for any difference in the
strength, or activity, of the animals. In Fig. 95, the cen-
L
Fig. 95.
A.
C
B
F
tre, E, upon which the bar moves, is considerably behind
the points of attachment, x\ and B. Hence, w^hen one end
falls back, so that the arm, AB, assumes the poshion, CD,
the foremost horse will have the disadvantage of acting
by a lever equal only to EF, while the other horse acts
by a lever equal to EC In the narrow streets of cities,
a custom has arisen of harnessing draught horses before
each other, in a single line, probably for the sake of room,
and the convenience of the driver. But, in this situation,
only the shaft horse has an advantageous hne of draught.
The remaining horses draw nearly in a horizontal line, and,
of course, at a disadvantage. Besides this, the foremost
horses, being attached to the ends of the shafts, do not act
directly upon the load, hut expend a part of their force
Fig. 96.
See a paper by Mr. Gilbert, in Brande's Journal, vol. xix.
HIGHWAYS. ROADS. PAVEMENTS. 19
in vertical pressure, upon the back of the shaft horse, which
is increased in drays, sleds, and all low carriages. This
will be seen by inspecting Fig. 96, where it is obvious, that
the hne of draught of the first horse cannot become direct,
without crippling down the shaft horse. The best mode
of remedying this difficulty, would apparently be, to attach
the traces of the forward horse to a strong hook, project-
ing downward from the end of each shaft, so as to bring
the traces into the proper line of traction, by directing them
more nearly towards the centre of the wheels. It is true,
that the shaft horse derives a certain degree of mechani-
cal advantage from vertical pressure, hke that which would
result from an increase of his weight. Yet this, although
useful in short exertions, is not so, when continued through
a day's fatigue.
HIGHWAYS.
Roads. — Roads, intended for the passage of wheel-car-
nages, are made more level, and of harder materials, than
the rest of the ground. In roads, the travel on which does
not authorize great expense, natural materials alone are em-
ployed, of which the best are hard gravel and very small
stones. The surface of roads should be nearly flat, with
gutters at the sides, to facihtate the running ofFof water. If
the surface is made too convex, it throws the weight of the
load unequally upon one wheel, and also that of the horses
on one side, whenever the carriage takes the side of the
road. Hence, drivers prefer to take the middle, OBtop, of
the road, and, by pursuing the same track, occasion deep
ruts. The prevention of ruts is best effected by flat and
solid roads, and by the use of broad wheels. It would
also be further effected, if a greater variety could be intro-
duced in the width of carriages. Embankments at the
sides, to keep the earth from sHding down, are best made^
by piling sods upon each other, like bricks, with the grassy
surface at right angles with the surface of the bank. But
stone walls are preferable for this purpose, when the ma-
terial can be readily obtained.
Pavements. — Pavements are stone coveriiags ol the
ground, chiefly employed in populous cities, and the most
20 ARTS OF LOCOMOTION.
frequented roads. Among us, they are made of pebbles,
of a roundish form, gathered from the sea-beach. They
should consist of the hardest kinds of stone, such as gran-
ite, sienite, &c. It flat stones are used, they require to
be artificially roughened, to give secure foothold to horses.
In Milan, and some other places, tracks for wheels are
made of smooth stones, while the rest of the way is paved
with small, or rough, stones.*
The advantage of a good pavement consists, not only in
its durability, but in the facility wuth which transportation on
it is effected. Hors«s draw more easily on a pavement,
than on a common road, because no part of their power is
lost, in changing the form of the surface. The disadvan-
tages of pavements consist in their noise, and in the wear
which they occasion of the shoes of horses, and tires of
wheels. They should never be made of pebbles so large as
to produce much jolting, by the breadth of the interstices. f
Wooden Pavements, made of hexagonal blocks of wood,
have been introduced in some of our cities. They have
been found more free from dust and noise than other pave-
ments. They are placed with the grain of the wood per-
pendicular to the ground, to prevent splintering, and give
better foothold. The most hard and durable woods are
best ; but the cheaper kinds are more used, for economy.
McMam Roads. — The system of road-making, which
takes its name from Mr. McAdam, combines the advan-
tages of the pavement and gravel road. The McAdam
roads ajre made entirely of hard stones, such as granite,
flint, &c., broken up, with hammers, into small pieces, not
exceeding an inch in diameter. These fragments are
spread u^ron the ground, to the depth of from six to ten
inches. At first, the roads thus made are heavy, and la-
* The streets of many of the ancient cities were paved, as those of
Rome, Pompeii, &c. But the streets of London were not paved in tne
eleventh century, nor those of Paris in the twelfth.
t Mr Telford has constructed, in England, a kind of paved road, in
*vhich the foundation consists of a pavement of rough stones and frag-
ments, having their points upward. These are covered with very small
Btone fragments, and gravel, for the depth of four inches, the whole of
which, when rammed down and consolidated, forms a hard, smooth,
and durahle, road.
BRIDGES. WOODEN BRIDGES. 21
borious to pass ; but, in time, the stones become consol-
idated, and form a mass of great hardness, smoothness,
and permanency. From the manner in which the stones
overlap each other, each stone, at !he surface, may be
considered as the apex of a pyramid, so that it cannot be
driven downward, without carrying before it a base of,
perhaps, a foot square, as will be seen by Fig. 97. The
Fi^. 97.
Stones become partly pulverized, by the action of carriage
wheels, and partly imbedded in the earth beneath them.
The consohdation seems to be owing to the angular shape
of the fragments, which prevents them from rolling in tbeii
beds, after the insterstices between them are filled. Mr.
McAdam advises, that no other material should be added
to the broken stones, apparently with a view to prevent
the use of clay and chalk, which abound in England. It
appears, however, that a little clean gravel, spread upon
the stones, causes them to consolidate more quickly, and
has the good effect of excluding the light street dirt, which,
otherwise, never fails to become incorporated, in large
quantities, among the stones.
BRIDGES.
The construction of small bridges is a simple process,
while that of large ones is, under certain circumstances,
extremely difficult, owing to the fact, that the. strength of
materials does not increase in proportion to their weight,
and that there are limits, beyond which no structure of
the kind could be carried, and withstand its own gravity.
Bridges differ, in their construction, and in the materials
of which they are composed. The principal varieties
are the following.
1. IVooden Bridges. — These, when built over sha\-
22 AKTS OF LOCOMOTION.
low and sluggish streams, are usually supported upon piles,
driven into the mud, at short distances, or upon frames
of timber. But, in deep and powerful currents, it is ne-
cessary to support them on strong 3tone piers, and abut-
ments, built at as great a distance as practicable from
each other. The bridge, between these piers, consists of
a stifi' frame of carpentry, so constructed, with reference
to its material, that it may act as one piece, and may not
bend, or break, with its own weight, and any additional
load, to which it may be exposed. When this frame is
straight, the upper part is compressed^ by the weight of
the whole, while the lower part is extended^ like the tie-
beam of a roof. But the strongest wooden bridges are
made with curved ribs, which rise above the abutments,
in the manner of an arch, and are not subjected to a lon-
gitudinal strain, by extension. These ribs are commonly
connected and strengthened with diagonal braces, keys,
bolts, and straps of iron. The flooring of the bridge may
be either laid above them, or suspended, by trussing, un-
derneath them. Wooden bridges are common in this
country, and some of them are of large size. One of the
most remarkable is the upper Schuylkill bridge, at Phil-
adelphia, which consists of a single arch, the span of
which is three hundred and forty feet.
2. Stone Bridges. — These, for the most part, consist
of regular arches, built upon stone piers, constructed in
the water, or upon abutments at the banks. Above the
arches is made a level, or sloping, road. From the nature
of the material, these are the most durable kind of bridges ;
and many are now standing, which were built by the an-
cient Romans. Several of the stone bridges across the
Thames, at London, are distinguished for elegance and
strength. The stone piers, on which bridges are support-
ed, require to be of great solidity ; especially, when ex-
posed to rapid currents, or to floating ice. Piers are
usually built with their greatest length in the direction of
the stream, and with their extremities pointed or curved,
so as to divide the water, and allow it to glide easily past
them. In building piers, it is often necessary to exclude
the water, by means of a coffer-dam. This is a temporary
CAST-IRON BRIDGES, ETC. 23
enclosure, formed by a double wall of piles and planks,
having their interval filled with clay. The interior space
is made dry by pumping, and kept so, till the structure is
finished.
3. Cast Iron Bridges. — These have been constructed
in England out of blocks, or frames, of cast-iron, so shap-
ed, as to fit into each other, and, collectively, to form ribs
and arches. These bridges possess great strength, but
are hable to be disturbed by the expansion and contrac-
tion of the metal with heat and cold.
4. Suspension Bridges. — In these, the flooring, or
main body of the bridge, is supported, on strong iron
chains, or rods, hanging in the form of an inverted arch,
from one point of support to another. The points of
support are the tops of strong pillars, or small towers,
erected for the purpose. Over these pillars, the chain
passes, and is attached, at each extremity of the bridge,
to rocks, or massive frames of iron, firmly secured under
ground. The great advantage of suspension bridges con-
sists in their stability of equilibrium, in consequence of
which, a smaller amount of materials is necessary for their
construction, than for that of any other bridge. If a sus-
pension bridge be shaken, or thrown out of equilibrium,
it returns, by its weight, to its proper place ; whereas the
reverse happens in bridges which are built above the level
of their supporters. One of the most remarkable suspen-
sion bridges, is that over the Menai strait, on the coast
of Wales, the span of which, or rather the water-way, is
five hundred feet, and the distance between the points of
support, or centre of the piers, five hundred and sixty
feet. It is suspended by four wrought-iron cables, which
pass over rollers, on the tops of the pillars, and are fixed
to iron frames, under ground, which are kept down by
masonry.
5. Floating Bridges. — Upon deep and sluggish water,
stationary rafts of timber are sometimes employed, ex-
tending from one shore to another, and covered with
planks, so as to form a passable bridge. In military op-
erations, temporary bridges are often formed by planks
laid upon boats, pontoons, and other buoyant supporters.
24 ARTS OF LOCOMOTION.
RAIL-ROADS.
In the best constructed public roads, a great amount
of power is expended, in overcoming the disad^vantages
which are inseparable from their construction, and the
nature of their materials. The chief loss of power de-
pends on the continual change of form, which carriages
occasion in roads, by the crushing of stones, cutting of
ruts, and other displacements of the material of which the
load is made ; which processes serve to consume power,
without forwarding the progress of the carriage.
The object of a rail-road is to furnish a hard, smooth,
and unchanging, surface, for wheels to run upon. These
surfaces, in most cases, consist of parallel rails of iron,
raised a little above the general level of the ground, and
having a gravelled road between the rails, so that the rail-
road combines the advantages of good foothold for horses,
where it is necessary to use them, and of smooth, hard,
surfaces, for the wheels to roll upon. The wheels are
made smooth and true, and guides, or flanges, to prevent
them from slipping off, are affixed, either to the wheels,
or to the rails, — most commonly, to the former.
Rail-roads are a modern invention, and their greatest
improvements have been made within the present century.
In comparing the effect of a rail-road with that of a com-
mon turnpike-road, a saving is made, according to Mr.
Tredgold,* of seven eighths of the power ; one horse on a
rail-road~ producing as much eftect, as eight horses on a
turnpike-road. In the effect produced by a given power,
the rail-road is about a mean between the turnpike-road
and a canal, when the rate is about three miles per hour ;
but, when greater speed is desirable, the rail-road may
equal the canal in effect, and even greatly surpass it. In
the Winter season, when canals are liable to be frozen,
rail-roads, if kept clear from snow and ice, may be al-
ways passable.
In the construction of rail-roads, it is desirable that they
bhould be made as level as possible. For this purpose,
the road is first graded^ by digging down the more ele-
* Treatise on Rail-roads and Carriages, p, 3.
EDGE RAIL-WAT.
25
vated parts, and raising those which are depressed. Hills
are usually passed through by deep cuts; and, in some in-
stances, perforated by tunnels, or hollow passages. Val-
hes and marshes are raised by embankments of earth, and
streams are crossed by wooden bridges, or by viaducts ol
stone, constructed with arches of regular masonry.
The earliest rail-roads appear to have been constructed
of wood only. But, at the present day, iron is employed
in all rails from which durability is expected. In ^sorne
cities, tracks of hewn stone are laid for wheels, in the
streets ; but these are seldom executed with sufficient ac-
curacy, to deserve the name of rail-ways. Of the iron
rail-road, there are three principal varieties. 1. The
Edge rail. 2. The Tram road. 3. The Single rail.
Edge Rail-way. — In this species, which is now prefer
red to all others, and is, indeed, the only one now much
in use, the rails are laid with the edge upward, and the
carriage is retained upon them by a flange, or projecting
edge, attached to the wheels, instead of the rail. These
rails were originally made of cast-iron, about three feet
long, and four or five inches deep in the middle, the out-
line being curved on the under side, to produce equality
of strength. Fig. 9S, represents a side-view of the old
Fig. 98.
cast-iron rail-way. The ends of the rails are received in
a piece of cast-iron, called a chair, and these chairs are
affixed to large blocks of stone, or logs of w^ood, called
sleepers, which are previously placed in the ground, upon
a proper level. Fig. 99, on the next page, is a section,
or end view, of the rail-road, together with the wheels of a
carriage, and the flange which serves to guide them.
Rails are now almost universally made of wrought-iron.
As this material is costly, when employed alone, it is some-
times used in thin bars, as a covering to wooden rails, par-
ticularly in this country, where timber is plenty, and iron
II 3 XII.
26
ARTS OF LOCOMOTION.
Fig. 99.
expensive.* But the most common rails are of solid iron,
rolled out in lengths of several yards, the edges, espec-
ially the upper, being straight, and thicker than the other
parts. Wrought-iron rails have the advantage of being
longer, and, therefore, reducing the number of joints ; a
circumstance which greatly increases the strength, as well
as smoothness, of the road.
Mr. Trautwine has published, in the Frankhn Journal,
the following transverse sections of eight varieties of par-
allel rails, employed on different rail-roads in the United
States. They are drawn to a scale of one fourth the full
* The durability of this combination of wood and iron, remains to
be settled by longer experience. It must be greatly inferior to that of
iron alone.
TRAMS. SINGLE RAILS. 27
size, and accompanied by a statement of the weights, per
lineal yard.
Weights.
No. 1. Columbia and Philadelphia, per yard, 41i lbs.
a 2. " " " 33 "
" 3. Germantown and Norristown, " 39 ','
" 4. Camden and Amboy, " 394 '^
" 5. Boston and Providence, " 54 "
" 6. Wilmington and Susquehanna, " 40 "
" 7. Alleghany Portage, " 40 ''
" 8. Boston and Providence, " 40 "
Tram-roads. — Tram-roads are flat rails, made usually
of cast-iron, with an elevated edge, or flange, on one side,
to guide the wheels of carriages in their path. Tram rails
are weaker than edge rails, when made of the same
amount of material, and it is sometimes necessary to
strengthen them with ribs underneath. They are capa-
ble of being used for ordinary wheel carriages, but the
introduction of wheels which are not perfectly smooth, is
always injurious to the road. Tram-roads are more lia-
ble to be covered with dirt, than rails of other kinds, and
are now httle used.
Single Rail. — Carriages may be made to run upon a
single rail, by deviating the rail from the ground, and sus-
pending the load beneath it. In Mr. Palmer's rail-way,
the rail is about three feet above the surface of the
ground, and is supported by pillars, placed at distances
of about nine feet from each other. The carriage con-
sists of two receptacles, or boxes, suspended, one on each
side of the rail, by an iron frame, and having two wheels
placed one before the other. The rims of the wheels
are concave, and fit the convex surface of the rail ; and
the centre of gravity of the carriage, whether loaded or
empty, is so far below the upper edge of the rail, that
the receptacles hang in equilibrium, and will bear a con-
siderable inequality of load without inconvenience, owing
to the change of fulcrum, allowed by the breadth of the
rail, which is about four inches. The alleged advantages
of the single rail are, that it is more free from lateral fric-
tion than the other kinds of rail-way, and that, being high-
28 ARTS OF LOCOMOTION.
er from the ground, it is less liable to be covered with
dust and gravel ; and, lastly, that it is more economical,
the construction of one rail being less expensive than of
two. It has not, however, been much introduced into use.
Passings, or Sidings. — When the amount of travel on
a rail-road is very great, it becomes necessary that the
road should be double, one set of tracks being provided
for carriages moving in each direction. Where there is
less travel, a single road is sufficient, if it be provided
with double places, called sidings, for carriages to pass
each other, at convenient distances. The siding, or pas-
sing place, is a short length of additional track, laid by the
side of a line of rail- way, and connected with it, at each
extremity, by suitable curves, the rails being constructed
and disposed in such a manner, that the carriages can
either proceed along the main hne, or turn into the sid-
fng, as may be required.
To accomplish this, the portion of rails, forming the
junction of the siding with the main hne, is made mova-
ble, so as to join either track-way. This portion is term-
ed a switch, and the points where one rail crosses an-
other, are termed crossing points. These last are gener-
ally fixed or immovable ; suitable grooves being left, on
their surface, for the passage of the flanges of the carriage
wheels on either track-way.
The Turn-plate, or Turn-table, is a contrivance for re-
moving rail-way carriages from one line of rails to another.
They are, generally, made for crossings at right angles
with each other, but can be adapted to any angle that
may be required. They consist of an iron framing, upon
which iron gratings, or w^ood plankings, are laid, thereby
forming a table, or platform, two pairs of rails being fixed
on the surface of the same, crossing each other at right
angles. This platform turns upon a centre pivot, wiiich
rests upon another iron frame, set on masonry, friction
rollers being inserted between them, at the extreme edges
of the table.
Curves. — The term curve is applied to a sudden bend,
in a hne of road, canal, or rail-way. Curves, upon rail-
ways of less than three fourths of a mile radius, should be
PROPELLING POWER. LOCOMCJ I irfiS. 29
avoided, as the centrifugal force, arising upon them, lias a
tendency to tlTrow the train off the rails. They also pro
duce an injurious amount of friction, which wastes pow-
er, and wears the flanges of the wheels.
When the rail- way crosses a public road, it is made to
pass at a lower level than the common surface, and is
protected from carriage wheels, by an elevated edging of
wood, or stone ; bridges are preferred, whenever the situa-
tion permits them to be made. Rail-ways require to be
free from dirt, which greatly increases the resistance.
Mr. Palmer found, upon a tram-road, that it required nine-
teen per cent, more power to draw the same carriages
when the rails were slightly covered with dust, than when
they were swept clean. The edge rail, however, being
convex on its upper surface, retains but httle dust.
Propelling Power. — Horses were originally employed
for drawing loads upon rail-ways, a horse being supposed
capable of drawing eight times as much, as upon a com-
mon road. But Locomotive steam-engines are now gen-
erally employed upon rail-ways, of any considerable
length. They were, at first, made to propel carriages, by
means of a toothed wheel, which acted upon a rack at-
tached to one of the rails ; but, at the present day, they
are made to act by the friction, only, of the carriage wheels
upon the plain rail. These engines are always made of
high pressure, since those of low pressure are rendered
too heavy, by the w^eight of the water necessary for con-
densation. Great improvements have lately been made
in the construction of locomotive engines, in consequence
of which, th^y have been enabled to attain the extraordi-
nary speed of thirty or forty, and, in some short experi-
ments, even of seventy, miles, per hour. (See Steam
Engine.)*
Locomotive Engines differ considerably from other
steam-engines, in their mode of construction ; and numer
ous modifications are found necessary, to render the ma
chine suitable for a rapid transit, the principal of which
are the combination of the engine and boiler in one, and
a contrivance for the rapid generation of steam.
* Franklin Journal, jcix. page 407, New Series.
3*
30 ARTS OF LOCOMOTION.
It became necessary, to form the boiler of much smaller
dimensions, in proportion to its power, than was before
customary, and to reduce the size of the cylinders. A
greater degree of strength was also required, in securing
the several parts of the framing together, in order to ren-
der the w^hole proof against the sudden shocks and strains,
to which it is subjected.
Locomotives were in a very imperfect state, previous
to the opening of the Liverpool and Manchester rail-way,
having merely one flue, passing through the boiler, and
returned again to the fire-box, at which end the chimney
was situated. A greater velocity than eight miles an hour
could never be attained by them, owing to the small ex-
tent of evaporating surface. They did not possess above
one quarter the power of the present locomotives.
The directors of that rail-way, having, in the year
1829, offered a premium of five hundred pounds for the
best locomotive engine, the first stimulus was given to the
subject. The Rocket engine, by Mr. G. Stevenson, prov-
ed successful in obtaining this premium. Li the boiler
of this engine, tubes were introduced, for the first time,
which greatly increased the evaporating powers of the
engine ; and, although locomotives have since been con-
siderably modified, yet this has formed the basis of all the
great improvements, which have taken place. A descrip-
tion of it will be given, under the head of Steam Engine.
Mr. Stevenson's engine weighed only four and a half
tons, and the evaporating surface was three times the ex-
tent of that in the former engines, which weighed up-
wards of seven and a half tons. It attaine.d a speed of
twenty-nine miles an hour, and an average velocity of four-
teen and a half miles an hour. It was soon after found,
that, by constructing engines of greater size, with increased
evaporating powers, ample amends would be made for
the additional weight. Heavier engines were introduced
on the Liverpool and Manchester rail-way ; and the loco-
motives, in general use, at the present time, weigh from
nine to thirteen tons. The power of a modern locomo-
tive engine, having tweh^e-incn cylinders, and an eighteen-
STATIONARY ENGINES. 31
mch stvoke of piston, is computed at about thirty-eight or
forty horse power, at high velocities, and seventy or eigh-
ty horse power, at a slow rate of speed.
The rapid generation of steam, in these locomotives,
is owing to the great number of tubes, and to their thin-
ness, whereby a large surface of water receives its heat
quickly, through a thin partition. An advantage is sup-
posed to be derived from the final escape of the steam,
which is discharged into the chimney.
Various improvements have been introduced into the
locomotive engine, one of which consists in the use of
six wheels, instead of four. In this country, many en-
gines are constructed with six wheels, the first four of
which are united by their axles, so as to form a kind of
separate carriage, which is made to support one end of
the locomotive. This carriage turns on a central bolt,
like the fore axle of a wagon. It has the advantage,
that the pressure is distributed more equally, and that the
wheels accommodate themselves better, to curvatures of
the road.
Stationary Engines are used to draw up loads where
the ascent is too steep for locomotives to ascend.
Where the declivity of the road is great, loaded carriages
sometimes descend, by their own gravity, and, at the same
time, draw up the empty ones, by means of pullies. To
prevent carriages from acquiring too great a velocity, in
descending, a crooked lever, called a brake, or convoy,
is apphed to the surface of the wheels, so as to retard
them by its friction.* When loaded carriages are trans-
ferred from one part of the road to another, of greater
elevation, they are either drawn up an inchned plane, with
ropes, by horses, or stationary engines ; or, in some cases,
they may be lifted perpendicularly, by pullies. This meth-
od, however, is seldom practised.
* A retarding friction is produced, when necessary, in mountaincus
countries, upon common roads, by chaining one of the wheels, when
the carriage goes down hill, so as to prevent its turning. The same
effect is produced, in a safer manner, by placing a wooden shoe, like a
runner, under one of the wheels.
32 ARTS OF LOCOMOTION.
CANALS.
Canals are artificial channels for water, cut for the pur-"
pose of admitting inland navigation. The great utility of
canals, in facilitating transportation, has caused them to be
constructed in all ages. The canals of the ancients were
chiefly made on one level, so as to form merely artificial
rivers, or creeks. Those of the moderns, by means of
locks, are carried, indiscriminately, over ground which is
depressed, or elevated. In level tracts of country, if the
earth is of suitable character, canals are easily made.
But, in loose and crumbling soils, in undulating, rocky,
and mountainous, tracts, and in those which are intersected
by large streams, their construction becomes expensive
and difficult. To surmount these difficulties, loose soils
are defended with firmer materials, vallies are passed by
embankments, hills are penetrated by deep cuttings or
tunnels, rivers are crossed with aqueducts, and declivities
are ascended and descended by locks. In order that wa-
ter may not be wanting in any part of the canal, a supply
is ensured at the highest level, and this gradually passes
off through the locks, to the lowest. The streams v.-hich
furnish the water at this, and other, points, are called
feeders.
Embankments. — Canals are dug with sloping sides, to
prevent the banks from caving in. The boats being, in
almost all cases, drawn by horses, a firm, uninterrupted,
towing path is formed on one of the banks. The banks
are hable, in time, to become indented and washed away,
by the constant agitation of the water, occasioned by the
passage of boats. To prevent this, they are sometimes
secured, by driving close rows of stakes against the banks ;
but, the only effectual protection is found in waUing the
banks with stone. When the canal crosses a section of
country, the surface of which is lower than the intended
surface of the water, the canal is raised to the proper
level, by means of embankments. These are artificial
baaks, or dykes, made of such materials as will not be
liable to leak, and of such form and strength, that they
will not be broken by the pressure of the water. The
AQUEDUCTS. TUNNELS. 33
surface of these banks is of a sloping form, and is secured
by sodding, and, in some instances, by piles, or stone
walls. Where the nature of the earth renders leakage
probable, it is common to cover the bottom and sides of
the canal with a lining of puddle, which is formed from
loam, or clay, and gravel, worked up with water. For
additional security, a trench is dug, in each bank, to a
greater depth than the bottom of the canal, and filled with
puddle.
It sometimes happens, that the embankments act as a
dam, to prevent the land, on one side of the canal, from
being properly drained. In this case, culverts, or sub-
terranean passages, are constructed underneath the canal,
but not communicating with it, to effect the necessary
draining. Culverts are made of brick, or stone, and re-
quire to be strong and tight.
Aqueducts. — When a canal crosses a river, or a deep
ravine, it is supported, at the proper level, by an aqueduct.
This structure resembles a stone bridge, formed of strong
piers and arches, of regular masonry, rendered as tight as
possible, with hydraulic cement. Upon the top, a level
channel for the water is formed. This is secured with
strong and tight walls, on the sides, and lined within by a
coating of clay. Room for the towing path must be preserv-
ed, on one of the sides. In England, aqueducts have
sometimes been made of casViron.
Tunnels. — Tunnels are subterranean passages, most
frequently cut through the base of hills, to afford a level
water-course for canals. Tunnels are also made for the
passage of rail-ways, and, in some cases, of highway-roads.
When they are obHged to be cut through solid rock, which
is done chiefly by blasting, their formation is difficult ;
but they require no artificial security for their subsequent
protection. But tunnels, which are made in soft earth, re-
quire to be arched over, for their whole length, with stone,
or brick ; and, in loose, springy ground, the bottom, like-
wise, must be defended with an inverted arch. That tun-
nels may be properly ventilated, especially while digging,
shafts, or vertical passages, are sunk, at proper distances,
in which fires are kept burning, to create a current for dis-
34 ARTS OF LOCOMOTION.
charging the foul air. One of the most remarkable tun-
nels is that at Worsley, on the Duke of Bridgewater's
canal, which, with all its branches, is estimated at eigh-
teen miles in length.
Gates and Weirs. — As, all canals are liable to have
their banks broken through, during violent rains and fresh-
ets, it is important to lessen the injury, which results from
such accidents, by retaining as much of the water in the
canal as possible. To effect this object, safety-gates and
stop-gates are placed, at suhable distances from each other,
on the canal, so that, by closing them, at any time, in case
of accident, the escape of that part of the water, which is
beyond them, may be prevented. These gates are some-
times attached to the sides, and sometimes lie upon the
bottom.
Certain parts of the banks, called Weirs, are made lower
than the rest, to discharge the superfluous water, and keep
the surface at a proper level. To prevent them from
being gullied, or worn away, by the attrition of the water,
they are commonly made of stone, or, sometimes, of wood.
Locks. — When a canal changes from one level to an-
other, of different elevation, the place, where the change
of level occurs, is commanded by a Lock. Locks are
tight, oblong enclosures, in the bed of the canal, fur-
nished with gates, at each end, which separate the higher,
from the lower, parts of the canal. When a boat passes
up the canal, the lower gates are opened, and the boat
glides into the lock ; after which, the lower gates are shut.
A sluice, communicating with the upper part of the canal,
is then opened, and the lock rapidly fills with water, ele-
vating the boat on its surface. When the lock is filled to
the highest water level, the upper gates are opened, and
the boat, being now on the level of the upper part of the
canal, passes on its way. The reverse of this process is
performed, when the boat is descending the canal.
Locks are made of stone, or brick, and, sometimes, ol
wood. The walls are sometimes erected upon an inverted
arch, and also upon piles, if the soil is alluvial, or loose.
They are laid with hydraulic cement, and rendered im-
pervious to water. The gates are commonly double, re-
LOCKlS. 35
sembling folding doors, turning upon coin-posts ^ which are
next the walls. They meet each other, in most instances,
at an obtuse angle, and the pressure of the water serves to
keep their contact more firm. The hydrostatic pressure,
in these cases, being in full force, in a direction perpendic-
ular to the surface of the gates, has a different action from
that of the pressure of gravity, appHed to a roof, or simi-
la.r structure, and gives to long gates a greater compara-
tive disadvantage than to short ones. Cast-iron gates are
sometimes used, in England, curved in the form of a hori-
zontal arch, with their convex side opposed to the water.
Valves are small sliding shutters, which admit a stream of
water, for the purpose of gradually filling, or emptying, the
lock, to prevent the shock of suddenly opening the gates.
In situations, where there is a scarcity of water, the
waste, occasioned by frequently opening the gates, for the
passage of boats, is too great for the amount supplied to
the canal. In these cases, to economize the water, re-
servoirs are provided, at different heights, on each side of
the lock. The water, in the upper parts of the lock, is
discharged nito these reservoirs, and only that in the lower
parts is suffered to escape into the lower canal. After-
wards, the water in these reservoirs is used to fill again the
lower parts of the lock, and thus, the same w^ater is made
use of, a second time.
In China, where inland navigation is much practised,
it is said there are no locks, but boats are transferred,
from one level to another, by means of inclined planes.
This method is sometimes practised, in Europe, and it had
a zealous advocate in the late Mr. Fulton. To effect this
transfer most advantageously, two boats, passing in oppo-
site directions, are connected together by a chain, passing
over a pulley. One boat, in descending the plane, assists,
by its weight, to draw the other upward. Sometimes,
instead of inclined planes, perpendicular lifts have been
proposed, by which the boats are hoisted directly, by pul-
lies, from one level to another, or lowered, in the opposite
direction, by the same means. The objection to all these
modes exists in the strain, to which the boats are exposed,
unsupported by the pressure of the water. Various ex-
36 ARTS OF LOCOMOTION.
pedients have been proposed, for altering the level oi the
water, and transferring boats, by means of large plungers,
diving chests, &c.; but none oi uiem, as yet, appear to
have been approved in practice.*
Fig. 100.
Boats. — Canal boats are made narrow, for passing each
other, and draw water proportioned to the depth of the
canal. Their length is limited only by that of the locks.
They are drawn by horses, on the tow-path, being kept,
by the rudder, from coming in contact with the bank. No
species of oars, poles, or paddle-wheels, is allowed, on
account of the injury done to the bottoms and banks, by
their use. It is said, however, that the steam-engine has,
in some cases, been used, without injury to the canal, by
causing the paddle-wheels to work in a water passage, or
casing, which passes through the boat, above its bottom.
Size of Canals. — Canals differ greatly from each other,
not only in their length, but their size, and the draught of
water which they admit. One of the largest canals, as
far as the volume of water is concerned, is the great
Dutch canal, which connects the city of Amsterdam with
the Helder, on the north coast of Holland. This canal
is fifty miles in length, one hundred and twenty-four feet
in width, at the surface of the water, thirty-six feet wide,
at bottom, and about twenty-one feet deep. It is large
enough to permit one frigate to pass another. ' The Cal-
edonian canal extends from the Murray Frith, on the
eastern coast of Scodand, to Loch Eil, on the western,
and admits of the passage of large ships. It is one hun-
dred and twenty feet wide, at the water surface, and fifty
wide, at bottom. The depth of water is twenty feet.
The distance, from sea to sea, is about fifty-nine miles,
of which thirty-seven and a half is lake navigation, and
* Repertory of Arts, vols. i. ii. and xxiii.
SAILING. FORM OF A SHIP. 37
twenty-one and a half is cut.* The canal of Languedoc,
in France, is sixty-four leagues in length, and connects
the Atlantic ocean with the Mediterranean sea. It is
sixty-four feet wide, at the surface, and navigable for ves-
sels of one hundred tons. The great New York, or Erie,
canal is three hundred and sixty miles long, and extends
from the Hudson river, at Albany, to Lake Erie, at
Buffalo. It is forty feet wide, at the surface, twenty-eight
feet wide, at bottom, and has four feet depth of water.
SAILING.
Form of a Ship. — The movement of bodies through
water, if performed within certain hmits of velocity, is at-
tended with less resistance than that which takes place in
most other modes of transportation. A body, however,
of given size, will encounter a greater or less resistance
from the water, according to its proportions, and the sort
of surface which it opposes to the fluid. In calculating
the proper form for a ship, it is necessary to consider the
kinds of pressure, to which bodies, moving in fluids, are*
subject. If we suppose an oblong square box, or paral-
lelopiped, as ABCD, in Fig. 101, to move through the
Fig. 101.
C I?
water, in the direction of its length, the pressure will be
increased before, and diminished behind it, the surface
of the water being elevated, at the anterior extremity, and
depressed, at the posterior ; an efiect which increases, in
a high ratio, as the velocity becomes greater. The prin-
cipal part of the water, which is before the moving body,
divides and passes off by the sides ; but a certain quantity
of what is called dead water is pushed along, in advance of
the moving body, nearly in the same manner as if it were
* Supplement to the Encyclopedia Britannica, and Edinburgh Ency-
clopedia.
II. 4 XII.
38 ARTS OF LOCOMOTION.
a part of ihe body itself. The shape of this dead water,
at the surface, is found to be that of an irregular triangle,
and hence it becomes advantageous to add to the moving
body an extremity, or boic^ having nearly the same shape
as the dead water, and occupying its place, as in the dot-
ted line, BED. On the other hand, there occurs, behind
the moving body, a depression of surface, and a partially
empty space, which is also of a triangular, or wedge, form,
consisting of the room which the moving body has just left,
and into which the water, upon each side, has not yet flow-
ed. The cavity, which is thus formed, resists the progress
of the body, by its negative pressure. Its effect is readily
understood, when we consider, that, if the water before the
moving body be raised one foot, while the water behind
it is depressed one foot, the difference of pressure, upon
the two extremities, will be equal to that resulting from two
feet. On this account, it is advantageous to add to the
moving body a tapering, or wedge-shaped, extremity, be-
hind, capable of occupying this cavity, and nearly answer-
ng to it in shape, as represented by the dotted line, AGO.
The consequence will be, that the water, which is advanc
ing from both sides to fill up the vacuity, will meet the ta
pering sides of the vessel soon enough to obviate, or great-
ly diminish, the negative pressm^e. The form, produced by
this general outline, varied by a proper curvature of the
sides and bottom, corresponds nearly to that which is adop-
ted in the construction of ships, and also to that pur-
sued by Nature, in the structure of fishes. If a vessel be
intended for a fast sailer, its proportionate length, and its
sharpness, before and behind, must be increased, since
both the positive and negative pressure, and the extent of
the dead water and vacant space, will increase with the
velocity.
Keel and Rudder. — The use of the keel, which is a
projecting timber, extending the whole length of the ship's
bottom, is to assist in confining the motion of the ship to
its proper direction, and, by its lateral resistance, to dimin-
ish the disposition to roll, or vibrate, from side to side.
The rudder, which is a perpendicular part attached, by
braces, resembhng hinges, to the stern-post of the vessel.
EFFECT OP THE WIND. 39
serves to govern the ship's course, by altering the relative
resistance of its two sides. Thus, while the ship is under
way, if the rudder is turned to one side, it receives an
impulse from the water on that side, causing the stern to
turn tow^ards the opposite side, where no such resistance
exists, thus altering the directit)n of the keel, and the
general course of the vessel.
Effect of the Wind. — When a ship sails in the same
direction as the wind, she is said to he. scudding, or sail-
ing before the wind, and if she had but one sail, it would
act with the greatest advantage, when perpendicular, or
nearly so, to the wind.
When a ship advances against the wind, and endeavors
to proceed, in the nearest direction possible, to the point
of compass from which the wind blows, she is said to be
close-hauled. A large ship will sail against the wind with
her keel at an angle of six points with the direction of the
wind, and sloops, and smaller vessels, may sail much near
er. When a ship is neither sailing before the wind, nor
close-hauled, she is said to be sailing large. In this
case, her sails are set in an obHque position, between the
direction of the wind, and that of the intended course ; as
represented in the various plans of vessels in Fig. 102,
on page 40, where the direction of the wind is represented
by the arrow, and the position of the yards and sails, which
is necessary for^proceeding on the various points of com-
pass, is shown by the transverse lines on each plan. The
relation of the wind to the course of the vessel is deter-
mined by the number of points of the compass, between
the course she is steering, and the course which she w^ould
be steering, if close-hauled. In Fig. 102, the ships, [a
and 6,] are close-hauled, and the ships, [c and c?,] the for-
mer steering east by north, and the latter west by north,
have the wind one point large. The ships, [e and /,]
one steering east, and the other west, have the wind two
points large. In this case, the wind is at right angles
with the keel, and is said to be upon the beam. The
ships, [g and /i,] steering southeast, and southwest, have
the wind six points large, or, as it is commonly termed,
upon the quarter, and this is considered as a very favora-
40
ARTS OF LOCOMOTION.
Fig. 102.
ble manner of sailing, because all the sails cooperate to
increase the ship's velocity ; whereas, Vhen the wind is
directly aft, as in the vessel, [m,] it is partly intercepted by
the after sails, and prevented from striking, with its full
force, on those which are forward. The force of a wind
which strikes obliquely upon the sails, supposing them
flat surfaces, is resolvable into two forces, one of which
tends to push the vessel ahead, and the other to push
her sideways. If the form of the vessel, instead of being
oblong, were circular, like a tub, she would move in the
direction of the diagonal of a rectangle, representing these
two forces, and her course would be at right angles with
the position of the sail, or in the direction of the line AB,
in Fig. 103. But, owing to the oblong shape of the vessel,
and the influence of her keel, it requires about twelve
STABILITY OF A SHIP. 41
times as much force to pusn her sideways, as to push her
head foremost.* The obhque impulse, therefore, will
carry her a great distance forward, in the time that she is
drifting a short distance to the leeward, and it is this re-
lative difference of progress, which enables a vessel to
advance, even against the wind. The angular deviation
of a ship's real course, from her apparent course, upon
which her head is directed, is called the leeway. In the
vessel, [Fig. 103,] with the wind blowing in the direction
of the arrows, and the sails set as represented, if the ves-
sel were moving in a rail-way, or unchangeable channel,
her course would be BD ; but, in the water, she drifts so
much to the leeward, that her real course is BC, and the
angle, CBD, represents the amount of leeway.
Stability of a Ship. — The masts of a ship, when acted
upon by the pressure of the wind against the sails, are so
many levers, tha tendency of which is, to overset her.
To counteract this tendency, a sufficient weight of ballast,
or cargo, is stowed in the bottom of the hold, to carry
the centre of gravity into the lower part of the hull, so
that this part will always preponderate, while the relative
buoyancy of the upper part causes the vessel to right, as
often as her position is disturbed. If the ballast is too
light, or is stowed too high in the hold, the vessel is said
to be too cranky and rolls more, and cannot carry so
much sail, without danger of oversetting. On the other
hand, if the ballast is too heavy, and placed too low, the
vessel is said to be too stiff, and not only draws so much
water as to impede her velocity, but is liable to have
♦ Robinson's Mechanhal Philosophy, vol. iv. p. 620.
4*
42 ARTS OF LOCOMOTION.
her masts endangered, by the shocks which result from
the suddenness of her motions. In regard to shape, an
increase of the width of a shi{) increases her stabihty, but,
at the same time, detracts from her power as a fast sailer.
Steam Boats. — Experiments on the propulsion of ves-
sels, by steam, were made in Europe, and this country,
at different times, during the last century; but the first
successful introduction of steam navigation, on a large
scale, was made in America, by the late Mr. Fulton,
about the year 1807. The application of the steam-en-
gine to navigation, has given to vessels the advantage of
greater speed and regularity, in the performance of their
passages, without interruption from the ciiangeable, and
often adverse, operation of the elements. In the action
of the steam-engine, as in that of rowing, a vessel is pro-
pelled by a succession of impulses, which act against the
inertia of the water.
A power acting within a boat, whether of men, of
horses, or of steam, may be applied to the water, in va-
rious ways. Some of the principal of these are the fol-
lowing. 1. A system of oars, or paddles, has been
made to act with alternating strokes, rising out of water
at the end of each stroke. 2. An alternating paddle
has been contrived, w4iich is continually immersed, and
which folds up, like the foot of a w^ater-fowd, during the
backward stroke. 3. It has been pr(^osed to drive a
current of air, or a current of water, out at the stern of
the vessel. 4. Spiral wheels and water-screws, or
wheels with oblique vanes, hke those of a windmfll, have
been made to turn under water, with their axes parallel
to the keel of the vessel. 5. Obhque planes, acting with
an alternate, instead of a revolving, stroke, were recom-
mended by Bernoulli. 6. Paddle-wheels. These, from
their simplicity, and advantageous mode of action, have, in
common use, superseded all the rest. They consist of
paddles, or float-boards, attached to the arms, or spokes,
of a wheel, the axis of which is at right angles with the
keel. Their common place is on the sides of the boat,
as in Fig. 104, on the opposite page.
The outline of the float-boards, or paddles, is com-
STEAM-BOATS.
Fig. 104.
43
monly rectangular, though ^Ir. Tredgold recommends that
'heir outer extremity should be parabolic. The best po-
sition for the paddles is in a plane, passing through the axis
of the wheels ; but with this position, they strike the water
obliquely, in entering, and lift a considerable quantity, on
quitting it ; both of which motions occasion loss of pow-
er. Attempts have been made to correct this disadvant-
age, by various mechanical arrangements, in which the
paddles are made to enter and leave the water perpen-
dicularly ; but want of simplicity, and objections of vari-
ous other kinds, have prevented them from coming into
use. It has be"en proposed to fix a series of paddles up-
on longitudinal chains, passing round wheels, and parallel
to each side of the vessel. By this mode, a number of
perpendicular paddles would act upon the water at once ;
but it will be seen, that, as no more of these paddles can
operate usefully, than are sufficient to put the water be-
tween.them into motion, a part of the series will be less
useful, than if it acted upon water at rest. In wheels of
the common form, it is advantageous to have a double
row of paddles, one outside the other, and so placed, that
the paddles of one series shall be opposite the intervals
of the other, and thus enter the water successively, and in
different places.* This plan is the one most generally
adopted, in American steam-boats. In Perkins's propel-
ling wheel, the paddles are placed obliquely, in regard to
the axis of the wheel, and the w^heel itself is placed ob-
* For examinations of the different propelling powers, see the Edin-
burgh Encyclopedia, article ' Navigation Inland,' ascribed to Mr. Tel
"ord ; also, Tredgold on the Steam Engine, p. 309.
44 ARTS OF LOCOMOTION.
liquely, in regard to the keel of tb»-boat. This arrange
ment is such, that the paddles enter and leave the water
obliquely, but, at the time of their greatest immersion, they
are at right angles with the keel, and in the most favora-
ble position for propelling the boat.
The average speed of a well-constructed steam -boat
has been assumed at fourteen miles per hour, and the
greatest speed at sixteen miles.*
Steam-boats have been considered as best adapted to
the navigation of rivers, and straits, or sounds, where the
water is comparatively smooth. In the open sea, the vio-
lence of the waves renders the action of the paddle-wheels
irregular, and it was, for a long time, thought difficult for
them to carry fuel sufficient to supply the engine, during
long voyages. The steam-ship Savannah first crossed
the Atlantic, in 1819, and was twenty-one days, from land
* Mr. W. S. Redfield, of New York, has addressed to Lieutenant Hos-
ken, the commander of the Great Western steam-ship, a letter, in which
he says : " Tiiere is, if T mistake not, some misapprehension prevail
ing, both in England and America, in regard to the ordinary, as well as
maximum, speed of the best steam-vessels. This is mainly to be as
cribed to three causes : 1st. The erroneous statements which often find
their way into newspapers. 2d. To a mistaken estimate of the velo-
city of the tides and currents. And, 3d, to the erroneous popular esti-
mate of navigating distances, which, on nearly all internal, or coasting,
routes, in both countries, so far as my knowledge extends, are habitu-
ally overrated. This may explain, on one hand, the extravagant claims
to velocity, which are sometimes stated of American steam-boats ; and,
on the other hand, may account for the strange incredulity, which has
been manifested by Dr. Lardner, and others, not well acquainted with
the structure and performances of American steam-boats. The ac-
quaintance which I have had with the navigation of the Hudson, by
steam, during the last thirteen years, enables me to speak with confi-
dence on some of the points involved.
" The usual working speed of the best class of steam-boats, on the
Hudson, may be estimated at fourteen statute miles per hour, through
still water of good depth. That they are not unfrequently run at a
lower speed, is freely admitted. But the maximum speed of these
boats is, and has been, for several years, equal to about sixteen miles
per hour. In regard to the " admitted four miles per hour tide up the
Hudson," the admission is extremely erroneous. The average advan-
tage to be realized, in a passage on flood-tide, from New York to Al-
bany, is not more than one mile and a half per hour, or, at the most,
say twelve miles, in a passage to Albany, — equal to about one twelfth
of the distance, as performed under the most favorable circumstances "
STEAM-SHIPS. DIVING-BELL, 45
to land, during eighteen of which, only, she was able to
use her engine.
Steam Ships. — The difficulties attendant on marine
steam navigation, which, but a short time ago, were pro-
nounced, by some distinguished authorities, to be insur-
mountable, have been completely overcome by the intro-
duction, in 1838, of steam-ships of extraordinary size,
propelled by engines of great power. The Great West-
ern, which arrived at New York, from Bristol, in April,
1838, measured, for her extreme length, two hundred and
thirty-six feet, and in width, between the outside of the
paddle-cases, fifty-eight feet. The British Queen, which
followed in the next year, is two hundred and seventy-
five feet long, which is stated to be thirty-five feet longer
than any ship in the British navy. She has two engines,
of two hundred and fifty horse power each. It is now
settled, that the passage of the Atlantic may be made,
safely and successfully, by vessels of this size, and ac-
complished, under favorable circumstances, in less than a
fortnight.
The success attending these experiments has led to
the multiplication of ocean-steamers, which are intended
to ply upon all the great tracks of commerce, in the civil-
ized world. 'The communication between Europe and
the United States, as well as that with the West and East
Indies, and, indeed, with most of the important sea-ports
on the globe, may be considered as hereafter to be per-
formed, in half the time which was formerly required, and
with far greater certainty, in regard to the times of arrival
and departure.
Of the numerous steam-ships now building, or built, in
Great Britain, to ply between that country and foreign
ports, some are constructed entirely of iron. Some are
of immense size, exceeding that of the British Queen,
which has already been mentioned.
DIVING-BELL.
The diving-bell is an inverted vessel, containing air^
and used for the purpose of enabling persons to descend,
with safety, to great depths uuder water. It is made tight
46 ARTS OF LOCOMOTION.
at the top and sides, but is entirely open at bottom. Its
principle is the same with that ot" a gasometer, and may
be familiarly illustrated, by immersing an inverted tumbler
in a vessel of water. The air cannot escape from the in-
side of the vessel, being necessitated, by the order of spe-
cific gravities, to occupy the upper part of the cavity.
Diving-bells appear to have been first introduced, in the
beginning of the sixteenth century. They were first known
as objects of curiosity, only, but have been since applied
to tlie recovery of valuable articles from wrecks, the
blasting and mining of rocks, at the bottom of the sea,
and the practice of submarine architecture. They may be
made of almost any shape ; but the common form has been
that of a bell, or hollow cone, m.ade of w^ooden staves,
and strongly bound with hoops, having seats for the occu-
pants, on the inside. It is suspended with ropes, from a
vessel above, and is ballasted with heavy weights at bot-
tom, which serve to sink it, and to prevent it from turn-
ing over. More recently, diving-bells have been made of
cast-iron. The kind of bell used at Howth, near Dub-
hn,* is an oblong iron chest, six feet long, four broad,
and five high, thicker at bottom than at top, and weighing
four tons. It has a seat at each end, and is capable of
holding four persons. The upper part is pierced with
eight or ten holes, in which are fixed the same number of
strong convex glasses, which transmit the hght. As the
air in the bell becomes contaminated, by breathing, it is
renewed, by letting down barrels, or small bells, of fresh
air, which is transferred to the large bell ; or else, by
keeping up a constant supply, through a pipe, by nieans
of a forcing pump, which is worked by men at the sur-
face.
Persons who descend in diving-bells often experience
a \iam in the ears, and a sense of pressure, occasioned by
the condensation of the air, within the cavity of the bell.
These symptoms gradually pass off, or habit renders the
body indifferent to them, so that workmen remain under
water, at the depth of twenty feet or more, for seven oj
eight hours in a day, without detriment to the health.
♦Edinburgh Philosophical Journal, vol. v. p. 8.
SUBMARINE NAVIGATION. 47
Submarine Js\ivigation. — A machine was invented,
during the American Revolution, by Mr Bushnell, of
Connecticut, which was capable of containing a person in
safety, under water, and of being governed, and steered in
any direction, at pleasure. It is described* as being a
hollow vessel, of a spheroidal form, composed of curved
pieces of oak, fitted together, and bound with iron hoops,
the seams being caulked, and covered with tar, to render
them tight. A top, or head, was closely fitted to the ves-
sel, and served the purpose of a door. In this were in-
serted several strong pieces of glass, to admit the light.
The machine contained air enough to render it buoyant,
and to support respiration. A quantity of lead was at-
tached to the bottom, for ballast. The vessel was made
to sink, by admitting water, and to rise, by detaching a
part of the leaden ballast, or by expelling water with a
forcing pump. It was propelled horizontally, by means of
revolving oars, placed obliquely, like the sails of a wind-
mill, on an axis which entered the boat through a tight
collar, or water-joint, and was turned witli a crank with-
in. A rudder was also employed, for steering the vessel
When fresh air was required, the vessel rose to the sur-
face, and took in air through apertures at the top. Tlie
intention of this machine was, to convey a magazine of
powder under ships of war, for the purpose of blowing
them up. Several experiments were made with it,
which, though unsuccessful in their object, nevertheless
proved the practicability of this species of locomotion.
The late Mr. Fulton made various experiments on sub-
marine navigation, in a boat large enough to contain sev-
eral persons, furnished with masts and sails, so as to be
capaole of proceeding at the surface of the water, and,
also, of plunging, when required, below the surface. f
While under water, its motions were governed by two
machines, one of which caused it to advance horizontal-
ly, while the other regulated its ascent and descent, its
depth below the surface being known, by the pressure on
a barometer. A supply of fresh air was carried down in
* Silliman's Journal, vol. ii. p. 94.
t See Colden's Life of Fulton, 8vo. New York, 1810.
48 ARTS OF LOCOMOTION.
the boat, condensed into a strong copper globe, by which
the air of the boat was replaced, when it became unfit for
respiration. Mr. Fulton's object was the destruction of
ships of war, by bringing underneath them an explosive
engine, called a torpedo.
AEROSTATION.
Balloon. — A Balloon is a sphere, or bag, formed ol
some light material, such as silk, and rendered impervi-
ous to the air, by covering it with elastic varnish. It is
filled with a gaseous fluid, lighter than the surrounding
atmospheric air, and has a car suspended, at the bottom.
If the specific gravity of the whole mass is less than that
of an equal bulk of the atmospheric air, which surrounds
it, the balloon will ascend into the atmosphere, and re-
main suspended, until, by the escape of its gas, or other
means, it becomes heavier than the surrounding air, when
it will again descend. Balloons were invented in France,
by the Montgolfiers, about 1782. Those which were
first employed by them were filled with common air,
rarefied by heat ; but these required, that a fire should be
constantly kept burning beneath them, to keep them afloat.
Hydrogen gas was afterwards employed ; and this fluid,
being permanently about fourteen times less dense than
common air, is, undoubtedly, the best material for aeros
tation. Carburetted hydrogen, though heavier than hy-
drogen, has also been employed, of late, on account of its
cheapness, being furnished, in large quantities, at the man-
ufactories of illuminating gas.
Balloons are made, by sewing together pieces of silk,
the shape of which corresponds to that of the part includ-
ed by two meridians of the artificial globe. They have
also been made of linen, and of paper. They are var-
nished with a solution of elastic gum, torrender them tight.
A net-work is thrown over the top of the balloon, to
which is attached, by strings, a car of wicker-work, un-
derneath the balloon. The whole is kept down, by a
sufficient quantity of ballast, and ascends into tiie atmo-
sphere, when a part of the ballast is thrown over. It is
made to descend again, by sufl^ering a part of the gas to
escape through a valve, provided for the purpose.
PARACHUTE. 49
The regulation of the ascent and descent of balloons
is the extent of control, which has been hitherto obtained
over them. All attempts to guide or propel them, by
means of wings, sails, oars, &c., have hitherto failed, and
the machine can only proceed at the mercy of the winds.
The small degree of buoyancy, which balloons possess,
does not permit them to carry sufficient weight of male-
rial, to furnish the medium of an adequate propelling force.
By taking advantage, however, of favorable winds, voy-
ages have been made in them to the distance of three
hundred miles ; and persons have ascended to the height
of twenty thousand feet, and upwards. The velocity of
balloons varies with that of the wind, but has, in some
instances, amounted to the rate of seventy miles an hour.*
Parachute. — The danger, which attends falling from
great heights, is in consequence of the continual acceler-
ation of velocity, which faUing bodies experience. When,
however, the resistance of the atmosphere becomes equal
to the force of gravity, the motion is no longer acceler-
ated, but becomes uniform. A parachute is an appen-
dage to a balloon, formed somewhat like an umbrella, and
is designed to break the force of a fall, by means of the
large surface which it opposes, in its progress, to the at-
mosphere. It is made of silk or canvass, and is placed
underneath the balloon, having the car suspended from it
by cords. When the balloon is at any height in the air,
the parachute may be detached from it, and will imme-
diately fall with the car, to the ground. But the resistance
of so large a surface to the atmosphere, causes the fall to
be gradual and easy, so that a person may descend with
a parachute, in safety, from the greatest heights. The
size of the parachute, employed by M. Garnerin, and
with which he descended from a height of two thousand
feet, at Paris, in 1797, w^as twenty-five feet in diameter.
The parachute was folded up, at the beginning oT the fall,
* M. Gay-Lussac, on the 6th of September, 1804, ascended twen
';y-three thousand and one hundred feet above Paris. M. Garnerin,
September 21st, 1827, passed, in seven hours and a half, from Paris
to Mount Tonnere, a distance of three hundred miles. This voyage
was performed in the night, and daring a storm.
II. 5 XII
50 ELEMENTS OF MACHINERY.
but soon expanded itself, by the resistance of the atmo-
sphere. The only inconvenience, which was experienced>
arose from a violent oscillating motion.
Works of Reference. — Brewster's Edition of Ferguson
Lectures on Mechanics, &c. 2 vols. 8vo. 1823 ; — ANSTiCE,on Whee
Carriages ; — EdgewortHjOD Roads and Carriages, Svo ; — Depar-
ciEUx sur letirage des chevaux, in the Mem. de VAcad. Paris, 1760 ;
— Yovng's Lectures on Natural Philosophy ; — McAdam, on roads,
Svo. 1823 ; — Blvnt and Stevenson's Civil Engineer, fol. 1834,
&c. ; — Parnell, Treatise on Roads, 8vo. 1833 ; — Tredgold,
on Rail Roads, Svo. 1825 ; — Wood, on Rail Roads, Svo. 1825 ; —
Strickland's Reports on Canals, Rail Roads, &c., oblong fol. Phil
ad., 1820 ; — Article Canal, in Rees' Cyclopedia, written by Mr. J.
Farey ; Articles Navigation Inland, Railway, Bridges, Aeronautics,
&c., in the Edinburgh Encyclopedia ; — Chapman, on Canal Naviga-
tion, 4to. 1797 ; — Fulton, on Canal Navigation, 4to. 1796 ; — Smea-
ton's Reports, 3 vols. Svo. 1812 ; — Prony, Architecture Hydrau-
lique, 2 torn. 4to. 1790 ; — Belidor, Architecture Hydraulique, 4
torn. 4to. 1750 ; — De Cessart, Travaux HydrauliqueSy 2 torn. 4to.
1808 ; — Reports to the House of Commons on Roads, Steam Boats,
&c., 1822, &c. ; — Article Seamanship, in the Encyclopedia Brittani-
ca, by Prof. Robinson ; — Dupin, Voyage dans la Grand Bretagne,
6 vols. Svo. with plates, fol. 1825.
CHAPTER XV.
ELEMENTS OF MACHINERY.
Machines, Motion. Rotary, or Circular, Motion, Band Wheels,
Rag Wheels, Toothed Wheels, Spiral Gear, Bevel Gear, Crown-
wheels, Universal Joint, Perpetual Screw, Brush Wheels, Ratchet
Wheel, Distant Rotary Motion, Change of Velocity, Fusee. Al-
ternate, or Reciprocating, Motion, Cams, Crank, Parallel Motion,
Sun and Planet Wheel, Inclined Wheel, Epicydoidal Wheel, Rack
and Segment, Rack and Pinion, Belt and Segment, Scapements.
Continued Rectilinear Motion, Band, Rack, Universal Lever,
Screw, Change of Direction, Toggle Joint. Of Engaging and Dis-
engaging Machinery. Of Equalizing Motion, Governor, Fly
Wheel. Friction. Remarks.
JUachines. — By a machine, may be understood a com-
bination of mechanical powers, adapted to vary the di-
rection, apphcation, and intensity, of a moving force, s<?
MOTION. ROTARY, OR CIRCULAR, MOTION. *!
as to produce a given result. The advantage which ma-
chines possess, over common manual labor, is generally
that of increasing, or improving, the product of an oper-
ation. This end they accomphsh, by enabling us to ap-
ply a common force, more advantageously, or to employ
the most powerful force, derived from natural agents, with
precision and efficacy. By the aid of machinery, any
number of instruments, or operative parts, may be made
to move in concert, in every possible direction, with any
degree of velocity, and to reciprocate with each other
in perfect harmony, so that complex operations are per-
formed by them, with a precision which often exceeds
the skill of the most expert artist.
Motion. — The motion which takes place in machines
is, for the most part, either rotary or reciprocating. A
rotary motion is that, in which the moving parts revolve
round an axis, as in a wheel, a crank, or a fly. A recip-
rocating, or alternate, motion is that, in which a body re-
traces its own path, or moves alternately backward and
forward, in the same track, which may be curved, as in
the beam of a steam-engine, or rectilinear, as in the pis-
ton. Most compound machines possess both these kinds
of motion, or varieties derived from them ; and the dif-
ferent ways of producing and communicating them, in the
requisite times and places, constitute a principal subject
of attention with machinists.
ROTARY, OR CIRCULAR, MOTION.
When it is intended that one wheel, or axle, shall pro-
pel another, various contrivances are adopted, to connect
the propelling part w^ith that which is to be moved. The
mode of connexion is varied, according to the distance,
the relative velocity required, and the direction in which
motion is to be communicated.
Band Wheels. — If two wheels be connected by a belt,
or band, passing round their circumferences, they will
move simultaneously, provided the friction of the band~
is sufficient to prevent it from slipping. When a round
cord is used, any degree of friction may be produced, by
receiving the cord in a sharp groove, at the edge of the
52
ELEMENTS OF MACHINERY.
wheel. But the stiffness of cords forms, in nnaiiy cases,
an objection to their use. When a strap, or flat band, is
used, its friction may be increased, by increasing its width.
The surface at the circumference of a wheel, or drum,
which carries a flat band, should not be exactly cylindri-
cal, but a little convex ; in which case, if the band in-
cHnes to slip off, at either side, it returns again, by the
tightening of its inner edge, as may be seen in a turner'?
lathe. When wheels are connected, in the shortest man-
ner, by a band, as in Fig. 105, they move in the same
Fig. 105.
Fig. 106.
direction. If the band be crossed, as in Fig. 106, they
will move in opposite directions. Wheels, whose axes
are situated in different planes, may turn each other, if
the band be sufficiently long. If no slipping were to take
place in the band, wheels of equal size w^ould move with
equal velocity, and those of different sizes, wath velocities
inversely proportionate to their respective circumferen-
ces. But, since the band is liable to yield or slide, some-
what, during the revolution, the velocity of the driven
wheel is, commonly, a little less, in proportion, than that
of the wheel which drives it.
Rag Wheels. — Where it is necessary that the veloci-
ties should be exactly proportionate, also, where great
resistance is to be overcome, chains of various kinds are
substituted, by passing them round wheels, in the place
of belts and ropes. These chains lay hold upon pins, or
enter into notches, on the circumference of the wheels, so
as to cause them to turn simultaneously. Such wheels
are denominated rag-wheels^ and have a uniform relative
TOOTHED WHEELS. 53
velocity. [Fig. 107.] They are used in locomotive steam*
engines, chain water-wheels, &c.
Fig. 107-.
Toothed Wheels. — Toothed wheels afford a more re-
gular and effectual mode of communicating rotary motion,
than any other kind of connecting mechanism. They
move, of necessity, in opposite directions, and their rela-
tive velocity is inversely proportionate to their number of
teeth. Thus, if a wheel having forty teeth drives another
of ten teeth, the second will make four revolutions, while
the first makes one. The connexion of one toothed wheel
with another is called gear^ or gearing ; and, when both
wheels, with their teeth, are in the direction of the same
plane, it is called spur-gearing. It is desirable, in tooth-
ed wheels, as far as possible, to diminish friction, and to
produce uniformity of force and motion. A uniform mo-
tion may be produced, if the form cl the acting face of
the teeth be a curve of the epicycloidal Aind ; the outline
of the teeth of one wheel being the curve w'/iich would
be described, by the revolution of a curve upor. a g>en
circle, while the outline of the teeth of the other wheel is
described, by the same curve rolling within the circle. It
may also be produced, if the teeth of one wheel be
straight, circular, or of any regular figure, whatever ; pro-
vided the teeth of the other wheel be of a figure, com-
pounded of that figure and of an epicycloid.*
Of two wheels, which are unequal in size, the larger is
called the wheel., and the smaller, the pinion. The act-
ing portions of the wheel are called teeth ; and, of the
* For investigations relating to the teeth of wheels, see Camus, on
the Teeth of Wheels, translated, London, 8vo. 1806 ; — Buchanan, on
Mill Work, chap. i. &c. ; — Brewster's Ferguson's Lectures, vol. ii.
p. 119 ; — Gregory's Mechanics, vol. ii. p. 451 ; — also, a Treatise, by
Mr. Blake, in Silliman's Journal, vol. vii. p. 86.
*5
54
ELEMENTS OF MACHKNERY.
pinion, more commonly, leaves. The name of lanterns
is given to pinions with two heads, connected by cyhn-
drical teeth, or trundles. In Fig. lOS, the line, joining
Fig. 108
tho centres, B and F, of the wheel and pinion, is called
the line of centres, and, when this line is divided into two
parts, FA and BA, which are to each other, as the
number of leaves in the pinion is to the number of teeth
in the wheel, BA is called the primitive radius* of the
wheel, and FA, the primitive radius of the pinion ; while
the lines, or distances, Ff and Bb, are called the true radii.
The circles, X AX and RAFt, are called the primitive cir-
cumferences, and, by workmen, the pitch lines.
Friction, to a certain extent, cannot be avoided, in
teeth of the common kind, whose acting faces are at right
angles with the plane of the wheels, to which they belong.
It may, however, be much diminished, by making the
teeth as small and as numerous, as is consistent with their
strength ; for the quantity of friction necessarily increases,
with the distance of the point of contact from the line of
centres.
♦ Called the proportional radius, by Buchanan
SPIRAL GEAR. 65
tSpiral Gear. — In common cases, the teeth of wheels
are cut across the circumference, in a direction parallel
to the axis. In the spiral gear, now much used in cotton
mills, in this country, the teeth are cut obliquely, so that,
if continued, they would pass round the axis, like the
threads of a screw. In consequence of this disposition,
the teeth come in contact only in the line of centres, and
thus operate without friction. [Fig. 109 J The action
of these wheels, it is true, is compounded of two forces,
one of. which acts in the direction of the plane of the
wheel, and the other in the direction of its axis. The
latter force occasions a degree of friction, w'hich, being
expended at the end of the axle, may be regarded as in-
considerable. The remaining force goes to produce ro-
tary motion.
The spiral gearing has been apphed to clock-work, and
has the peculiarity, that it admits of a smaller pinion than
any other gearing. Thus, if a very small cylinder have
a spiral groove so cut in it, as to extend once round its
circumference, it will perform one revolution for every
tooth of the wheel which drives it. The groove may be
cut indefinitely near to the centre of the pinion, or cylin-
der, without weakening it so much as would happen in
other forms of the pinion.*
* The spiral gear has been used at Waltham, Mass., and elsewhere,
for about fifteen years, and is commonly considered, here, as the inven-
tion of Mr. White. Something analogous to it, under the name of
Inclined Plane Wheels, was published in London, by Mr. T. Shel-
'drake, in 1811.
56
ELEMENTS OF MACHINERY,
Bevel Gear. — When wheels are not situated in the
same plane, but form an angle with each other, the spur
gearing, already described, is changed for teeth of a dif
ferent description. In this case, the bevel gearing is
commonly employed, consisting of wheels, which are
frusta of cones, having their teeth cut obliquely, and con-
verging toward the point, where the apex of the cone
would be situated. According as the relative magnitude
of the wheels varies, the angle of the bevel must be dif-
ferent, so that the velocities of the wheels may be in the
same proportion, at both ends of their oblique sides, or
faces. For this purpose, the faces of all the teeth must
be directed to the point, where the axes of the two wheels
would meet. The bevel gearing is shown in Fig. 110,
and Fig. 116.
Fig. 110.
Crown Wheels. — Circular motion is also communicat-
ed, at right angles, by means of teeth or cogs, situated
parallel to the axis of the wheel. Wheels, thus formed,
are denominated crown, or contrate., w^heels. They act
either upon a common pinion, or upon a lantern. The
crown-wheel is represented in Fig. 111. It is less m use
than the bevel-gear, before described, having more friction
UNIVERSAL JOINT. PERPETUAL SCREW. 57
Universal Joint. — The contrivance called Hooke's
universal joint, is sometimes used, instead of wheels, to
communicate circular motion in an oblique direction. It
consists of two shafts, or axes, each terminating in a
semicircle, and connected together by means of a cross,
upon which each semicircle is hinged. [Fig. 112.] It is
Fk. 112.
obvious, that when one shaft is turned, the other must re-
volve likewise ; and this will be the case, whenever the
angle, by which one shaft deviates from the direction of
the other, does not exceed forty degrees. By means of
a double universal joint, circular motion may be com-
municated, at an angle of from fifty to ninety degrees.
Perpetual Screw. — The perpetual, or endless, screw,
sometimes called loorm^ by mechanics, is made use of to
convey circular motion from an axle to a toothed wheel,
situated in the direction of the same plane with the axle.
The relative velocity of a wheel driven by a screw is very
slow ; for, if the screw have only a single thread, the
wheel will advance the breadth of one tooth, only, for eacb
Fig. 113.
kS
aa
53 ELEMENTS OF MACHINERY.
revolution of the screw. This mechanism is of great use
in producing an equable slow motion, in machinery, and
also, in increasing mechanical power. [Fig. 113.] The
motion may be reversed, or conveyed from the wheel to
the screw, if the obliquity of the threads be sufficiently
increased. A spiral wheel and a toothed wheel may be
made to turn, with equal velocity, or any desired propor-
tion of velocity, by the construction represented in Fig.
/ ^4. A, is a wheel, seen edgeways, its axis being BC.
B<: /^z^c
Its circumference is furnished with spiral ridges, which,
as the wheel turns, cause the pinion, D, to revolve in the
plane of the axis, BC.
Brush Wheels. — In light machinery, wheels sometimes
turn each other by means of bristles, or brushes, fixed to
their circumference. They may, also, communicate cir-
cular motion, by friction only. In this case, the surface
brought in contact is formed of the end-grain of wood, or
it is covered with leather, or some other elastic substance,
and the two wheels are pressed together, to increase the
friction.
Ratchet Wheel. — The ratchet, or detent, wheel is in-
tended to prevent motion in one direction, while it per-
mits it in another. For this purpose, the teeth are cut
with their faces inclining in one direction, and a small
lever, or catch, is so placed, as to enter the indentations,
and stop the wheel, if it turns backward, but slides ovei
the teeth, without obstructing them, if it moves forward.
[Fig. 115.] Ratchet-wheels are generally employed to
DISTANT ROTARY MOTION. 69
pres^ent a weight, raised by a machine, from descending,
and to obviate other retrograde movements.
Fig. 115.
Distant Rotary Motion. — When it is required to trans-
mit circular motion to a distance, for example, from one
extremity, or story, of a building, to another, various meth-
ods are employed. The most common is, by band-wheels,
or drums, connected by leather belts of the requisite length.
This mode is considered most economical. -When a
precise velocity is required, a rolling shaft, geared at both
ends, as in Fig. 116, is to be preferred. A double crank.
Tier. 116.
having its two parts at right angles with each other, and
connected with a similar crank, by stiff rods, or bars, an-
swers the same purpose. [Fig. 1 17.] If triple cranks are
Fig. 117.
used, cords will serve, instead of bars, for connection, be-
cause, in this case, some part of the first crank will always
be in a situation to draw the second, and a rigid medium
will not be necessary.
60 ELEMENTS OF MACHINERY.
Change of Velocity. — It is sometimes necessary, thai
a machine should be propelled with a velocity which is
not equable, but which continually changes, in a given
ratio. This happens in cotton-mills, where it is neces-
sary that the speed of certain parts of the machinery
should continually decrease, from the beginning to the end
of an operation. To effect this object, two cones, or
conical drums, are used, having their larger diameters in
opposite directions. They are connected by a belt, which
is so governed, by proper mechanism, that it is gradually
moved from one extremity of the cones to the other, thus
acting upon circles of different diameter, causing a con-
tinual change of velocity in the driven cone, with relation
to that which drives it. [Fig. 118.]
A change of speed is also effected, by a decreasing series
of toothed wheels, placed, in the order of their size, upon
a common axis, and fixed. A corresponding series, in an
inverted order, are placed upon another axis, and not
fixed, but capable of revolving about the axis, like loose
pullies. The axis of this second series is made hollow,
and contains a movable rod, which has a tooth, project-
ing through a longitudinal slit in one side of the axis. This
tooth serves to lock any one of the wheels, by entering a
notch, cut for its reception. Only one wheel, however,
can be locked at a time, the others remaining loose, so
that the axis will revolve with a velocity, which is due to
the relative size of the particular wheel which is locked,
and of the wheel which drives it. By successively lock-
ing the different wheels, an increase, or decrease, of speed
is obtained.* [Fig. 119.]
* A mechanism of this kind is used in the cotton factory at New-
ton, Massachusetts, and there is one, nearly similar, in Bramah's plan-
ing machine.
CHANGE OF VELOCITY
Fig. 119.
61
Another mode of changing speed is produced, by a
large, and small, wheel, placed at right angles with each
other, and acting by friction only. The edge of the
smaller wheel is kept in close contact with the disc, or
flat surface, of the larger wheel, so that the smaller wheel
will revolve faster, or slower, according to the distance,
at which it is kept from the centre of tLe larger wheel.
The distance may be varied at pleasure [Fig. 120.]
Fig. 120.
It is sometimes requisite that a wheel, or axis, should
move with different velocity, in different parts of a single
revolution, as in orreries, &c. This may be effected, by
an eccentric crown-wheel, acting on a long pinion as in
l(.
¥11,
62 ELEMENTS OF MACHINERY.
Fig. 121. It may also be accomplished in a different
way, by a cone, furnished with spiral line of teeth, acting
on another cone, the position of which is reversed.
Fusee. — In the preceding arrangements for changing
velocity, there is a corresponding change of force, which
is in an inverse ratio to the change of velocity. They
may, therefore, be employed for varying force, as well
as speed. The fusee of a common watch is a contriv-
ance, adapted to this purpose. "When a watch is recent-
ly wound up, the spring, which propels it, is in the state of
greatest tension. As this spring relaxes, or uncoils itself,
its power decreases, and, in order to correct this inequal-
ity, the chain, through which it acts, is wound upon a spi-
ral fusee. The fusee, B, is an axis, surrounded by a spiral
groove, the distance of the groove from the axis being
made to increase gradually, from the top to the bottom, so
that, in proportion as the force of the spring is diminished,
it may act on a longer lever. The general outline of the
fusee must be nearly such, that its thickness, at any part,
may diminish, in the same proportion as it becomes more
distant from the point, at which the force would cease
altogether, the general curve being that of a hyperbole ;
\)ut the workmen have, in general, no other rule, than that
of habitual estimation. [Fig. 122.]
Fig. 122.
ALTERNATE, OR RECIPROCATING, MOTION.
This name is applied to movements which take place
continually, backwards and forwards, in the same path.
An alternate motion may take place about a centre, in
which case, the moving parts will describe arcs of circles,
as in a tilt-hammer, or the beam of a steam-engine ; or it
may be confined by guides, so as to pursue a rectilinear
path, as in the saw of a saw-mill. In most complex ma-
CAMS.
63
chines, both rotary and reciprocating motions occur, and
these motions are convert"^d into each other, by any of the
following contrivances.
Cams. — If the axis of a wheel be situated in any other
point than its centre, the wheel, thus rendered eccentric,
may produce, by its revolution, an alternate motion in any
part exposed to its action. Circles, hearts, ellipses, parts
of circles, and projecting parts of various forms, are made
to produce alternate motion, by continually altering the
distance of some movable part of the machine, from the
axis about which they revolve. Such projecting parts
are called cams.* In the various forms which are shown
in the figures, the part, removed by the cam, is supposed
to return, by its own gravity, or by some other power, so
as to keep up the alternate motion. In the circular ec-
centric cam, or wheel, [Fig. 123,] the sliding, or recipro-
cating, part, x\B, will ascend and descend, with an easy
motion, being never at rest, unless at the instant of chang-
ing its direction. Eccentric wheels, if surrounded by a
hoop, as at H, in PI. IX. perform the same office as
cranks. In the semicircular cam, [Fig. 124,] the recipro-
cating part will remain at rest, on the periphery of the cam,
during half the revolution, but, in the remaining half, it
w'ill approach the axis, and return. In the quadrant cam,
[Fig. 125,] the reciprocating part will remain at rest, on
the periphery, during the first quarter of the revolution ;
Fig. 123.
A
1
Fig. 124.
A
o
Fig. 125.
A
Fig. 126
A
o
Fig. 127.
A
^B r-^B ^B^B
S
^ ^ /
:^ c
* This word is spelt cam, camm, and camb, by different writers.
In French came. — Borgni^.
64
ELEMENTS 01 MACHINERY,
during the second, it will descend to the axis ; during the
Third, it will be at rest upon the axis ; and during the fourth,
it will return to its original situation. The narrow cam,
[Fig. 126,] causes the reciprocating part to rise and fall,
in one half the revolution, and to remain at rest, on the axis,
during the other half. In these figures, the angles. of the
cams are made sharp, for the sake of demonstration ; but,
in practice, they are generally rounded, to produce more
gradual changes of motion. The elhptical cam, [Fig.
127,] causes two alternate movements for each revolution ;
and the triple cam, in Fig. 12S, apphed to a tilt, or trip,
Fig. 128.
hammer, causes three strokes for one revolution. In thi:
case, the cams are called icipers, and it is common to
accelerate the reciprocal motion, by adding to the action
of gravitation, the elastic force of a spring, or by the re-
coil of the handle from a fixed obstacle. A cam, in the
form of a heart, called a heart-wheel^ is much used in
cotton-mills, to cause a regular ascent and descent of the
rail on which the spindles are situated.*
When an easy motion is desired, as in most large ma-
chinery, the acting outline of the cam should be curved .
but, to produce a sudden stroke, it should be straight
The number of cams may be indefinitely multiplied, if a
rapid, or vibrating movement, is required. This is, in
effect, done, when the teeth of a wheel act upon a spring,
or weight, as in a watchman's rattle, or in the feeder of
a grist-mill.
* For an investigation of the curves proper for different cams and
wipers, see Brewster's edition of Ferguson's Mechanics, vol. ii. p. 126,
&c. For producing an easy and uniform motion, spiral, epicycloidal,
and other curves, are requisite ; but, for abrupt, forcible, motions, such
as occur in tilt-hammers, curves of equal action are to be avoided.
CRANK. PARALLEL MOTION.
65
Crank. — The common crank affords one of the simp-
lest and most useful methods, for changing circular into
alternate motion, and vice versa. The single crank, [Fig.
129,] can only be used upon the end of an axis. The
bell-crank, [Fig. 130,] may be used in any part of an axis.
The double crank, [Fig. 131,] produces two alternate
Fig. 129.
Fig. 130.
Fig. 131.
M uT rt
ir
motions, reciprocating with each other. The alterna-
ting parts, in all these cases, are attached to the crank
by connecting rods, or by some of the kinds of mechan-
ism, hereafter described. The motion, produced by
cranks, is easy and gradual, being most rapid, in the mid-
dle of the stroke, and gradually retarded, toward the
extremes ; so that shocks and jolts, in the moving ma-
chinery, are diminished, or wholly prevented, by their use.
Parallel Motion. — The name of parallel motions is giv-
en to those arrangements, which convert circular motion,
whether continued or alternate, into alternate rectilinear
motion, and vice versa. Thus, the beam of a steam-en-
gine moves in circular arcs, while the piston moves in
right lines. They cannot, therefore, be rigidly connect-
ed together, without doing violence to the machine ; and
it becomes necessary to convert one movement into the
other, by the intervention of proper mechanism. A mov-
able parallelogram is principally used, for this purpose,
and will be described under the head of Steam Engine.
A similar contrivance, of a more simple form, is shown in
Fig. 132. CD, is a rod, moving back and forwards, in a
right line. Every point of junction is a hinge, or joint.
66
ELEMENTS OF MACHINERY.
GE, is a rod, movable about E, as a centre ; and FH, a
rod of the same length, movable about F, as a centre ;
these centres being equally distant from the path of CD.
GH, is a bar, connecting these two rods, and havmg the
rod, CD, attached, by a joint, to its centre. When the
whole is set in motion, the joint, G, will describe the cir-
cular arc, IK, and the joint, H, will describe the circulai
arc, GH, while the joint, C, will pursue an intermediate,
or rectihnear, course.
Various other methods are practised, to insure a rectili-
near motion, though most of them are attended with great
Fig. 133.
SUN AND PLANET WHEEL.
67
er friction than that last described. Thus, the alternating
part is often confined to a'rectilinear path, by shding in
grooves, guides, or holes, or between friction wheels ; a
connecting rod uniting the straight and circular motions,
as in the last instance. In Cartwright's steam-engine,
the straight movement of the piston is secured, by con-
necting it with two cranks, acting in opposition to each
other, and having their axles geared together by wheels,
as represented in Fig. 133, on page 6G,
The connecting rod may be dispensed with, if a trans-
verse groove, or slit, be cut in the alternating part, of a
length equal to the diameter of the crank's revolution ;
as in Fig. 1 34. The end of the crank, seen at [o,] in its
Fig. 134.
revolution, traverses the whole length of this groove, which
is cut in the crossbar, AB, while the main bar, CD, has
an alternate motion in the straight path to which it is con-
fined. As the space of ascent, or descent, of the bar,
CD, is always equal to the versed sine of the arc described
by the crank, the motion of the bar will be accelerated,
towards the middle of its oscillations, and retarded, to-
wards the extremes. A more equal motion can be pro-
duced, if desired, by substituting for the straight groove,
a curvilinear groove, somewhat like the figure co ; but
this method is attended with much friction, and little use.
Sun and Planet Wheel. — The mechanism which
bears this name, was invented by Mr. Watt, to convert
68 ELEMENTS OF MACHINERY.
reciprocating into circular motion, in the steam-engine ,
the use of the crank, for this purpose, being, at one time,
secured by patent to another individual. In Fig. 135, a
view is given of the sun and planet wheel. A, is the end
of a beam, having a reciprocating motion. B, is the fly-
wheel of the engine, to which a rotary motion is to be
communicated. Upon the axis of this fly-wheel, a small
toothed wheel is firmly fixed. A second toothed wheel
is connected to the first, by a loose crank, so as to be
capable of revolving freely about it. This second wheel
is firmly fixed upon the end of a connecting rod, which is
attached, by a joint, to the beam of the engine. The two
wheels being in gear, it is obvious, that as the beam. A,
rises and falls, the second wheel, with the assistance of
the fly, will revolve quite round the first ; and, if the
num_ber of teeth be equal, the first, or sun-wheel, must
perform two rotations on its axis, while the second, or
planet-wheel, revolves once round it.
The necessity of this will be more obvious, when we
consider, that, if one tooth of the planet-wheel, were con-
nected by a joint to one tooth of the sun-wheel, it would
act as a simple crank, and cause one revolution. But an
additional revolution is also necessary, because, during
the circuit, all the teeth of the planet-wheel must act
INCLINED WHEEL. EPICYCLOIDAL WHEEL.
69
upon those of the sun-wheel, thus turning it round, as in
common wheel-work.
Fig. 136.
C E
■ tl
D F
Inclined Wheel. — In Fig. 136, AB, is a wheel, placed
obliquely on its axis, CD. The edge, or periphery, of
this wheel, is received in a notch, at B, of a sHding bar,
EF. As the wheel revolves, the bar, EF, will move up
and down once, during each revolution. This reciprocal
motion may be indefinitely varied, by bending the edge of
the wheel into different curves and angles.
Epicycloidal Wheel. — A very beautiful method of con-
verting circular into alternate motion, or alternate into cir-
cular, is shown in Fig 137. AB is a fixed ring, or wheel,
Fig. 137.
toothed on its inner side. C, is a toothed wheel, of haft
the diameter of the ring, revolving about the centre of the
ring. While this revolution of the wheel, C , is taking place.
70
ELEMENTS OF MACHINERY.
any point, whatever, on its circumference, will describe a
straight line, or will pass and repass through a diameter
of the circle, once, during each revolution. This is an
elegant appHcation of the law, that, if a circle rolls on the
inside of another of twice its diameter, the epicycloid de-
scribed is a straight line. In practice, a piston, rod, or
other reciprocating part, may be attached to any point
on the circumference of the wheel, C.
Rack and Segment. — If an alternating motion is requir-
ed, the velocity of which shall be always equal, a rack is
best adapted to produce this effect. In Fig. 138, AB
Fig. 138.
a a parallelogram, having a rack on two opposite sides.
0, is a half wheel, toothed on its curved side, and having
its centre equally distant from the two racks. It is ob-
vious, from inspection, that, as this half wheel revolves, its
teeth will act successively upon the two racks, and cause
the parallelogram to move back and forwards, with a uni-
form motion. The change, however, from one direction
to the other, will be nearly instantaneous, so that this plan
will only answer in machinery which is very hght, or of
slow motion. The teeth of the half wheel must cover
somewhat less than half a circle, that they may not become
engaged in one rack, before they are disengaged from the
other.
Rack and Pinion. — Another contrivance, which ren-
ders the change more gradual, is represented in Fig. 139.
AB, is a double rack, with circular ends, fixed to a beam,
capable of moving in the direction of its length. The rack
IS driven by a pinion, P, which is capable of moving up
and down in a groove, [m?i,] cut in the cross-piece. When
the pinion has moved the rack and beam, until it comes ta
BELT AND SEGMENT. ^SCAPEMENTS.
71
Fig. 139.
„ %
P n
V
ar
V» a
^u
the end, B, the projecting piece [a] meets the spring, [5,]
and the rack is pressed against the pinion. The pinion,
then working in the circular end of the rack, will be forced
down the groove, [mn,] until it works in the lower side of
the rack, and moves the beam back in theopposite direction ;
and, in this way, the motion is continued. The motion
of the pinion in the groove will be diminished, if, instead
of a double rack, we use a single row of pins, which are
parallel to the axis of the pinion, as in some of the ma-
chines, called mangles.
Belt and Segment. — An alternate circular motion is
converted into an alternate rectilinear motion, in fire-en-
gines, dressing-machines, &c., by a belt, or chain, fasten-
ed to each end of a segment, or other portion of a wheel.
The two belts pass by each other, and are attached to the
opposite ends of an alternating part. When the segment
turns, in either direction, it draws after it the alternating
par^,, in a straight line. [Fig. 140.]
Fig. 140.
Scapements. — In clocks and watches, an alternating
motion is produced in the pendulum and balance-wheel,
72
ELEMENTS OF MACHINERY.
by means of the mechanism called a scapement. In the
more simple scapements, two teeth, called pallets, are
made to vibrate on a common axis. They are connect-
ed with a toothed wheel, in such a manner, that one pallet
enters between the teeth of the wheel, whenever the other
is thrown out of their reach. As the wheel revolves, its
teeth successively impinge against one or the other of
these pallets, and, by causing them successively to escape,
communicate to their axis a vibrating, or alternate, motion.
The crutch scapement, [Fig. 141,] is an arch, situated in
the same plane with the scape-wheel, and parallel to the
plane in which the pendulum vibrates. Its pallets suc-
cessively enter and escape from the teeth of the wheel,
and receive from it a vibrating motion. In the old, or com-
mon, watch scapement, [Fig. 142,] a contrate, or crown,
wheel is used as the scape-wheel, and the pallets [a and
b] are placed upon the axis of the balance-wheel, so as to
meet the teeth, successively, on opposite sides of the cir-
cumference of the scape-wheel. A variety of other more
complicated forms of the scapement are also in use.
Fig. 141.
Fig. 142.
BAND. RACK. 73
CONTINUED RECTILINEAR MOTION.
A long-continued rectilinear motion is not to be pro
duced in the parts of a machine, except so far as it par-
takes of the nature of a rotary, or a reciprocating, motion.
Thus, a band, passing round pullies, is a modification of
rotary motion, and a rack, which is obliged to return at
intervals, has a reciprocatmg motion. But, to a certain
extent, the motions of both may be regarded as conftti-
iiously rectilinear.
Band. — If it is required to produce motion, in a right
line, which shall be always in one direction, as, for exam-
ple, in the feeding parts of machines, a band, passing round
pullies or drums, is the method most commonly practised,
as in Fig. 105. If a precise velocity is required, the band
may be perforated with holes, and received upon short
pins, at the circumference of the wheels ; or the rag-wheel
and chain, represented in Fig. 107, may be substituted.
Rack. — If a slow rectilinear motion is required only
for limited times, such a mechanism may be used, as will
permit the moving part to retrace its own path, at inter-
vals, and regain its original situation. [Fig. 143.] A
rack, which is a straight bar, having teeth on one side, will
move in this manner, if it be acted on by a toothed wheel,
or by a perpetual screw. If the thread of a perpetual
screw be formed of different obliquity, in different parts
of its circumference, the progressive velocity of the rack
will be unequal, instead of being uniform. And, if a part
of the thread be in a plane, at right angles with the axis
of the screw, the rack will be at rest, while that part of
the screw revolves in contact with it.
XII.
74
ELEMENTS OF MACHINERY.
Universal Lever. — A rack is also propelled, by means
of a catch, or dog, connected with some part of the ma-
chine, which has an alternating motion. The catch caus-
es the rack to advance, the length of one tooth, at each
stroke of the alternating part. The universal lever, some-
times called the lever of La Garousse, consists of a bar
moving upon a centre, and havmg a movable catch, or
hook, attached to each side, and acting upon the oblique
te^h of a double rack, or of a ratchet-wheel, so that the
alternating motion of the bar causes a progressive motion
of the rack, or wheel. [Fig. 144.]
Fig. 144.
Screw. — A common screw is often made use of, to
produce rectilinear movements, when the motion is in-
tended to be very slow, or when great power is required.
Change of Direction. — A change, from one path, or
direction, to another, forming an angle with it, may be
produced, by several of the mechanical powders. Thus, a
cord, passing over a pulley, may change a perpendicular
to a horizontal motion, as at P, [Fig. 159,] or to one at
any other angle required. A bent lever, like that repre-
sented by y z, in PI. III., produces the same effect, pro-
vided the moving parts are confined, by guides, to their
respective paths. An inclined plane, also, if it moves
through the length of one side of a parallelogram, will
cause another body to move through the length of the
contiguous side, at right angles. This method, however,
is attended with much friction.
Toggle Joint. — The knee-joint^ ccmmonly called, in
OP ENGAGING AND DISENGAGING MACHINERY. 75
this country, toggle-joint, affords a very useful mode of
converting velocity into power, the motion produced be-
ing nearly at right angles with the direction of the force.
Its operation is seen in the iron joints which are used, to
uphold the tops of chaises. It is also introduced into
various modifications of the printing press, in order to
obtain the greatest power, at the moment of the impres-
sion. It consists of two rods, or bars, connected by a
joint, and increases rapidly in power, as the two rods ap-
proach to the direction of a straight line.* In Fig. 145,
a moving force, applied in the direction CD, acts with
great and constantly increasing power, to separate the
parts, A and B.
• C
OF ENGAGING AND DISENGAGING MACHINERY.
In many cases, particularly where numerous machines
are propelled by a common power, it is important to pos-
sess the means of stopping any one of them, at pleasure,
and of restoring its motion, without interfering with the
rest. To produce this effect, a great variety of combi
nations have been invented, under the name of couplings.
These, in most instances, are sHding boxes, which move
longitudinally upon shafts or axles, and serve to engage,
or lock, a shaft which is at rest, with one which is in mo-
tion ; so as practically to convert the two into one, until
* An investigation of the power of this combination, is given hy the
late Professor Fisher, in Silliman's Journal, \ol. iii. p. 320.
76 ELEMENTS OF MACHINERY.
they are again unlocked. Couplings are sometimes pro-
vided with clutches, or glands, which are projecting teeth,
intended to catch on other teeth, or levers, and thus lock
the shafts together. Sometimes they have bayonets, or
pins, adapted to enter holes. Sometimes, the connexion
is produced by friction alone, by pressing together sur-
faces, which are either flat, or conical. Sometimes, also,
wheels are thrown into^ and out of, gear, which is done,
by causing wheels to shde in the direction of their axles,
or, in some cases, by elevating and depressing the axle
itself. These methods, however, are difficult and un-
safe. The live and dead pulley afibrd, perhaps, the sim-
plest mode of engagement. They consist of two paral-
lel band-wheels, on the same axle, one of which is fast,
and the other loose, or capable of turning without the
axle. The band, which communicates the power, is
placed upon the loose pulley, when it is desired to stop
the machine, and upon the fast pulley, when it is intend-
ed to set the machine in motion. A common band may,
also, be made to admit of motion or rest, according as it
is rendered tense, or loose, by a tightening wheel, pressed
against hs side by a lever.
OF EQUALIZING MOTION.
In most machines, both the moving force, and the re-
sistance to be overcome, are liable to fluctuations of in-
tensity, at different times. As such variations influence
both the safety and efficiency of machines, it is necessa-
ry to provide against them, by some appendage, which
shall equalize either the supply, or the distribution, of the
power.
Governor. — The name of governor has been given to
an ingenious piece of mechanism, which has been intro-
duced, to regulate the supply of steam, in steam-engines,
and of water, in water-mills, so as to render the power
equable, and proportionate to the resistance to be sur-
mounted. It is represented in Fig. 146, on the opposite
page. x\B, and AC, are two levers, or arms, loaded with
heavy balls, at their extremities, B and C, and suspended,
by a joint, at A, upon the upper extremity of a revolv-
GOVERNOR. 77
ing shau, AD. At [a,] is a collar, or sliding box, cou-
nected to the levers, by the rods [a6, and ac,] with
joints at their extremities. It follows, that when the
weights, B and C, diverge, the collar [a] will move up-
ward, on the shaft. AD, and vice versa. The governor,
thus constructed, is attached to some revolving part of the
machine. In this state, if it turns too rapidly, the balls,
B and C, move outwards, by their centrifugal force, and
draw upward the collar, [a.] If, on the other hand, the
speed diminishes, the balls are allowed to subside, and the
collar moves down upon the shaft. In the steam-engine,
the collar has a circular groove, which receives the end of
a forked lever. As the collar rises and falls, this lever
turns upon its fulcrum, and acts, remotely, to open or close
a throttle-valve, which is placed in the main steam-pipe.*
Whenever, therefore, the machine moves too rapidly, the
balls recede from the centre, the collar rises, the lever
moves the valve, and, by partially closing the pipe, di-
minishes the quantity of steam admitted from the boiler.
If the machine moves too slowly, the reverse takes place,
and a larger amount of steam is admitted.
In water-wheels, where a greater power is necessary
to control the supply of water, the governor is usually
connected to the sluice-gate, by the intervention of wheel-
work. This may be done in several ways, one of which
* For a further account of the governor, see the article, Steam Eiu
gine.
7*
78 ELEMENTS OP MACHINERY.
IS as follows. The lower part of the shaft, AD, carries
a wheel at D, acting upon two others beneath it, M and
N. While the machinery moves with its proper speed,
the wheels, M and N, are both unlocked, and turn loosely
round their axles, and the gate is stationary. But, when
the velocity increases or diminishes, the collar [a] rises or
falls, and, by means of a cam, acts upon a lever above it,
or upon another below it, so as to lock one of the wheels,
M or N, by moving a clutch situated at [c?.] These
wheels, being upon a common axle, are capable of turning
this axle different ways. When, therefore, one wheel is
locked to the axle, it acts by turning a perpetual screw,
to open the sluice gate. When the other is locked, the
axle and the screw turn in the opposite direction, and
partially close the gate.
The foregoing are some, out of various, modes in which
the governor is appHed. In windmills, it is so adapted as
to increase the feeding, or supply of corn, when the mill
goes too fast, and also to vary the distance of the mill-
stones from each other, if necessary. It has also been
applied to clothe and unclothe the sails, in proportion to
the strength of the wind.
Fly Wheel. — It is an object of great importance, in
machines, to have the means of accumulating power, when
the moving force is in excess, and of expending it, when
the moving force operates more feebly, or the resistance
increases. This equahzalion of motion is obtained, by
what is called a fly, which is generally made in the form
of a heavy wheel, though, sometimes, in the form of arms,
or crossbars, with weights at their extremities. A fly
being made to revolve about its axis, keeps up the force,
by its own inertia, and distributes it, in all parts of its rev-
olution. If the moving power slackens, it impels the
machine forward ; and if the power tends to move the
machine too fast, it keeps it back.
Fly-wheels are capable of accumulating power to a
great extent. A small force, continually applied to the
surface of a heavy revolving wheel, will eccelerate its ve-
locity, till it shall be equal to that of a musket-ball, and
ts momeatum almost irresistible. Fjy- wheels, to act
FRICTION. 79
i^ith th<y greatesv efficacy, should be made with the least
possible surface, that their motion may not be impeded,
by the resistance of the air. They should be made of
iron, and, if they cannot be cast in one piece, they should
be firmly hooped, or bolted together, that the parts may
not separate, by their centrifugal force. Fatal accidents
have occurred from the bursting of large stones, used as
flies, or as grindstones, in cutlery works, their velocity,
and centrifugal force being so great, as to overcome their
cohesive attraction, and to project the parts to a distance,
with great violence.
Beside the modes already described, other methods
are employed, to retard and equalize the velocity of ma-
chinery. A kind of fly is used, in music boxes, and in
the striking part of clocks, in which the broad surface of
vanes, upon the circumference of a wheel, is made to act
against the air, until the resistance becomes equal to the
propelling force, so that the velocity can increase no fur-
ther, but becomes uniform. Pendulums and balances,
acted on through the difierent kinds of scapements, are
also means of equalizing motion.
FRICTION.
A part of the force, by which machines are moved, is
expended in overcoming their friction. Hence it is desir-
able to obviate, as far as possible, this kind of resistance.
Friction is supposed to arise, chiefly, from the roughness
and inequality of the surfaces of bodies. No pohsh can
be given to a surface, mechanically, so fine, as to render
it perfectly smooth. When surfaces move over each
other, a certain force is necessary to disengage the minute
asperities of one surface from those of the other, either
by causing them to rise over each other, or by bending
or breaking them down.
Friction is increased, by the roughness of bodies, and,
also, by the force with which they are pressed together.
But it is very little afiected by the extent of the surfaces
in contact. It is greatest, at the moment when motion
begins. It does not, however, change afterwards as the
velocity changes, but continues to retard, with a uniform
80 ELEMENTS OF MACHINERY.
force, whether the motion performed be slow, or i-apm.
There are several points, in regard to friction, upon which
writers are not agreed.
Friction in machinery is to be diminished, by making
the surfaces, which rub upon each other, as smooth as pos-
sible, and by covering them w th some unctuous substance.
Black lead, in fine powder, is sometimes interposed be-
tween surfaces, to diminish friction, and soapstone, applied
in the same manner, is still more useful. It is supposed,
Dy some, that different metals, moving upon each other,
occasion less friction, than surfaces of the same metal.
But the most important mode of diminishing friction is, to
employ a rolling or turning motion, instead of a sliding
motion, in all cases where it is practicable ; and, by sim-
plicity of construction, to avoid all unnecessary contact of
moving surfaces.
Remarks. — In the construction of machines, no subject
is more deserving of attention, than simpHcity of parts and
structure. The more complex machines are, the more
expensiva they are to erect, the more liable to get out of
order, and the more difficult to repair. An increased
expenditure of power is also occasioned, by their friction.
A complex machine may evince great ingenuity on the
part of the inventor, and may have cost much labor and
science to complete it. Yet it is sure to be superseded,
the moment that a more simple, cheap, or expeditious
way of attaining the same object is discovered. The im
provement of the mechanist, or engineer, more frequent
ly consists in the simplification of his means, than it does
in the construction of complex and difficult pieces of work
manship.
Works 3f Reference. — Buchanan, on Mill Work, and other
Machinery, 2 vols. 8vo. 1823 ; — Robison's Mechanical Philosophy,
vol. ii. p. 181 ; — Nicholson's Operative Mechanic, 8vo. 1825 ; —
Gregory's Mechanics, 1826 ; — Brewster's edition of Ferguson's
Mechanics, 1823 , — Borgnis, Mechanique Appliquee aux Arts, 4to
Paris, 1818, Tom. 3, Composition des Machines; — Lanz et Bet
TANCOURT, sur 1(1 ComposHion des Machines, Paris, 4to. 1819 ;—
IIachette, Traite Elementaire des Machines ; — Leupold, TJie
atrum Machinarum Universale, 7 vols, folio, Loipsic, 1724 to 1774
MOVING FORCES USED IN THE ARTS. 81
CHAPTER XVI.
OF THE MOVING FORCES USED IN THE ARTS.
Sources of Power, Vehicles of Power. Animal Power, Men, Hors
es. Water Power, -Overshot Wheel, Chain Wheel, Undershot
Wheel, Back Water, Besant's Wheel, Lambert's Wheel, Breast
Wheel, Horizontal Wheel, Barker's Mill. Wind Power, Vertical
Windmill, Adjustment of Sails, Horizontal Windmill. Steam Pow-
er, Steam, Applications of Steam, By Condensation, By Generation,
By Expansion, The Steam Engine, Boiler, Appendages, Engine, Non-
condensing Engine, Condensing Engines, Description, Expansion En-
gines, Condenser, Valves, Pistons, Parallel Motion, Locomotive En-
gine, Power of the Steam Engine, Projected Improvements, Rotative
^ Engines, Use of Steam at High Temperatures, Use of Vapors of
Low Temperature, Gas Engines, Steam Carriages, Steam Gun.
Gunpowder , Manufacture, Detonation, Force, Properties of a Gun,
Blasting, Magnetic Engines.
Sources of Poicer. — It is the office of machines, to re-
ceive and distribute motion, derived from an external
agent, since no machine is capable of generating motion,
or moving power, within itself. The sources from which
the moving power, apphed to machinery, is obtained, are
various, according to the nature of the object, and the
amount of force, which is required. Men and animals,
water, wind, steam, and gunpowder, are the principal
agents, employed as first movers in the arts. Their pow-
er may be ultimately resolved into those of muscular en-
ergy, gravity, heat, and chemical affinity. But, although
these are the sources of all the important force, which is
artificially employed, in moving large masses of matter,
yet, certain other agents are also capable of producing
motion, upon a more limited scale ; such as magnetism,
electricity, capillary attraction, &c.
Vehicles of Poicer. — Besides the original forces which
have been mentioned, there are certain intermediate agents,
which serve to accumulate and transmit power, after the
first mover has ceased to operate. These agents com-
monly act, either by their elasticity, their gravity, or their
inertia. Springs, and compressed air, are examples of
82 MOVING FORCES USED IN THE ARTS.
vehicles, acting by their elasticity, and their usefulness
continues, only, till they have recovered the situation from
which they were disturbed by another force. In like
manner, a weight, acting by its gravity on an axle, or
wheel, prolongs, for a season, the influence of the power,
by which it was w^ound up. Fly-wheels are also vehi-
cles which serve, by their inertia, to continue the action
of a force while it intermits. Vehicles of power are
highly useful, in equalizing the irregularities which are in-
cident to prime movers, in prolonging their action through
convenient periods of time, and in multiplying the modes
of their application.
A fundamental distinction among mechanical agents,
both original and secondary, consists in this ; that, in some,
the intensity of their action, or the acceleration they prc^
duce in a given time, is the same, whether the body acted
upon be at rest, or in motion ; in others, it is greatest,
when the body acted on is at rest, and becomes less, as
its velocity increases. Gravity is the only force, which
is certainly known to act, with equal intensity, on bodies
m motion, and at rest ; though magnetism, probably, pos-
sesses the same property. Every other important power
acts more forcibly on a body at rest, than on one which
has already acquired motion, in the direction in which it
acts.* This happens with the strength of animals, the
impulse of fluids, and the elasticity of springs.
ANIMAL POWER.
Muscular energy is exerted through the contraction of
the fibres which constitute animal muscles. The bones
act as levers, to facihtate and direct the application of this
force, the muscles operating on them, through the medi-
um of tendons, or otherwise. Muscular power is much
greater in some animals, than it is in man, owing to their
size, or more active mode of life. It is greatest in beasts
of prey.
jyien. — The power of a man to produce motion, in
weights or obstacles, varies, according to the mode in
which he.apphes his force, and the number of muscles
* See Playfau's Outlines of Natural Philosophy, vol. i. p. 107.
MEN. 83
fvhich are brought into action. In the operation of turn-
ing a crank, a man's power changes, in every part of the
circle which the handle describes. It is greatest, when
he pulls the handle upward, from the height of his knees ;
next greatest, when he pushes it down, on the opposite
side ; though, here, the power cannot exceed the weight
of his body, and is, therefore, less than can be exerted,
iTi pulling upward. The weakest points, are at the top
and bottom of the circle, where the handle is pushed, or
drawn, horizontally.
If a windlass be provided with two cranks, placed at
right angles with each other, two men will perform much
more work, than they could, if the cranks were discon-
nected ; because, at the moment one puts forth his strength
to the least advantage, the other is exerting his with the
greatest efiect.
The mode i# which a man can exert the greatest active
strength, is in pulling upward from his feet ; because the
strong muscles of the back, as well as those of the upper
and lower extremities, are then brought advantageously
into action, and the bones are favorably situated, by the
fulcra of the levers being near to the resistance. Hence,
the action of rowing is one of the most advantageous
modes of muscular exertion ; and no method which has
been devised for propelling boats, by the labor of men,
has hitherto superseded it.
According to Mr. Buchanan, the comparative effect
produced, by different modes of applying the force of a
man, is nearly as follows. In the action of turning a
crank, his force may be represented by the number seven-
teen. In working at a pump, by twenty-nine. In pul-
ling downward, as in the action of ringing a bell, by thirty-
nine. And in pulling upward from the feet, as in rowing,
by forty- one.*
In estimating the different applications of animal force,
we must take into consideration, not only the resistance
they can overcome, but the velocity with which they
move, and the length of time, for which they can be con-
* See Brewster's edition of Ferguson's Mechanics, vol. ii. p. 9
The whole numbers are 1742, 2856, 3883, and 4095.
84 MOVING FORCES USED IN THE ARTS
tinned. Violent efforts are not true specimens of a n^ian a
labor, since they can be exerted for a short time only.
A moderate computation of an ordinary man's uniform
strength is, that he can raise a weight of ten pounds, to
the height of ten feet, once in a second, and continue this
labor, for ten hours in the day.* This is supposing him
to use his force, under common mechanical advantages,
and without any deduction for friction.
Horses. — Horses are often employed as movers of
machinery, by their draught. A horse draws with great-
est advantage, when the line of draught is not horizon-
tal, but inclines upward, making a small angle with the
horizontal plane, as already stated, page 18. The force
of a horse diminishes, as his speed increases. The fol-
lowing proportions are given by Professor Leslie, for the
force of the horse, employed under different velocities.
If his force, when moving at the rate (# two miles per
hour, is represented by the number one hundred, his force,
at three miles per hour, will be eighty-one ; at four miles
per hour, sixty-four ; at five miles, forty-nine ; and, at
six miles, thirty-six. These results are confirmed, very
nearly, by the observations of Mr. Wood.f In this way,
the force of a horse continues to diminish, till he attains
his greatest speed, when he can barely carry his own
weight.
Various estimates have been made of a horse's pow-
er, by Desaguhers, Smeaton, and others ; but the esti-
mate, now generally adopted, as a standard for measuring
the power of steam-engines, is that of Mr. Watt, whose
computation is about the average of those given by the
other writers. The measure of a horse's power, accord-
ing to Mr. Watt, is, that he can raise a weight of thirty-
three thousand pounds, to the height of one foot, in a
minute.
In comparing the strength of horses, with that of men,
.^f.saguliers and Smeaton consider the force of one horse
be equal to that of five men ; but writers differ on this
* ibject.
* Young's Lectures on Natural Philosophy, vol. i. p. 131
t Treatise on Rail Roads, p. 239.
WATER-POWER. OVERS HOT- WHEEL. 86
When a horse draws in a mill, or engine of any kind,
he is commonly made to move in a circle, drawing after
him the end of a lever, which projects, hke a radius, from
a vertical shaft. Care should be taken that the horse-
walk, or circlcy in which he moves, be large enough in
diameter ; for, since the horse is continually obliged to
move in an oblique direction, and to advance sideways,
as well as forward, his labor becomes more fatiguing, in
proportion as the circle, in which he moves, becomes
smaller.
In some ferry-boats and machines, horses are placed
on a revolving platform, which passes backyvard, under
the feet, whenever the horse exerts his strength, in draw-
ing against a fixed resistance ; so that the horse propels
the machinery, without moving from his place. A horse
may act within still narrower limits, if he is made to stand
on the circumference of a large vertical wheel, or upon
a bridge, supported by endless chains, which pass round
two drums, and are otherwise supported by friction wheels.
Various other methods have been practised, for applying
the force of animals ; but most of them are attended whh
great loss of power, either from friction, or from the un-
favorable position of the animal.
WATER-POWER.
Water and wind, considered as prime movers, are ap-
plications of the force of gravity ; since, without gravity,
there would be neither wind, nor currents of water. The
force of water is, generally, applied to the circumference
of wheels, which it causes to revolve, either by its weight,
by its lateral impulse, or by both, conjointly. Water-
wheels are generally used in one of three forms. These
are, the over shot-wheel^ in which the water descends from
the top of the wheel to the bottom ; the breast-ioheel, in
which it is received at about half the height of the wheel ;
and the undershot-wheel^ where it acts by the impulse of
a current, flowing under the wheel. The overshot wheel
is the most powerful kind, and is always to be employed,
where a sufficient fall of water can be obtained.
Overshot Wheel. — This is a wheel, or drum, the cir-
II. 8 XII-
86 MOVING FORCES USED IN THE ARTS.
cumference of which is occupied by a series of cavities,
commonly called buckets, into which the water is deliv-
ered from one, or more, spouts, at the top of the wheel.
By inspecting Fig. 147, it will be seen, that the buckets
Fiff. 147.
W:
W
on one side of the wheel are erect, and will, consequently,
become loaded with water ; while those on the other side
are inverted, and, of course, empty. It follows, that the
loaded side will always preponderate, and, by descending,
will cause the wheel to revolve.
If it were possible, says Dr. Robison,* to construct
tho buckets in such a manner, as to remain completely
^lled with water, till they came to the bottom of the wheel,
the pressure, with which the water urges the wheel round
its axis, would be the same, as if the extremity of the
horizontal radius were continually loaded wuth a quantity
of water, sufficient to fill a square pipe, whose section is
equal to that of the bucket, and whose length is the diam-
eter of the wheel. But such a state of things is impossi-
ble ; and, if a bucket be full, while at top, it will begin to
lose water, as soon as it turns into an oblique position,
and must continue to do so, till it reaches the bottom.
The attention of engineers has been directed to giving
the buckets such a form, as will enable them to retain the
water, for the longest time, on the circumference of the
wheel. The form represented in Fig. 148, on page 87,
answers this purpose tolerably well, and, from its simplici-
ty, is the one most commonly used ; but it may be im-
proved still further, by giving an additional incfination,
* Mechanical Philosophy, vol. ii. p. 592.
OVERSHOT-WHEEL. 87
Fig. 148. Fig. 149.
\
.iiward, to the outer edge of the bucket, as seen in Fig.
149. ' As the best economy of the water-power requires
that the buckets should not be completely filled, the form,
here represented, will retain the water, until it has de-
scended low on the wheel. To promote this object still
further, Mr. Burns has divided the bucket by a partition,
which is parallel to the rim of the wheel, constitutmg one
bucket within another. In this mode of construction, the
water does not enter with the same facihty, but is longer
in escaping.*
In order to prevent the inertia of the water, when it is
first laid upon the buckets, from impeding the motion of
the wheel, it is desirable that the water, when it enters,
should have a velocity corresponding, as nearly as possi-
ble, to that with which the wheel is revolving. And, as
we cannot give to the water, the direction of a tangent to
the wheel, the velocity, w^ith which it is delivered on the
wd:ieel, must be so much greater than the intended veloci-
ty of the rim, that it shall be equal to it, when it is esti-
mated in the direction of a tangent. To facilitate, as
much as possible, the entrance of the water, it is common
to deliver the w^ater through an aperture, w^hich is divided
by thin plates of board, or metal, placed in an oblique
position, so as to direct the stream of water into the
buckets, in the most perfect manner, as represented in
Fig. 152, on page 93. In order to detain the water, as
long as possible, the lower part of the wheel is often made
to revolve in a concave cavity, just large enough to re-
ceive it, and called, in this country, the apron, as seen in
Fig. 155, on page 95.
A difficulty often occurs, in the entrance of water into
* We are informed by Dr. Brewster, that Burns's improvement has
not been introduced by him into practice, owing to the difficulty of
filling the inner buckets. — Mechanics^ vol. r. p. 49
88 MOVING FORCES USED IN THE ARTS.
the buckets, by the resistance of the air, ah'eady in the
bucket, which causes the water to regurgitate, and spill.
This evil may be entirely prevented, by making the spout
considerably narrower than the wheel, so as to leave
room for the escape of the air, at the two ends of the
bucket.
The pressure of the atmosphere occasions, sometimes,
a serious obstruction to the motion of overshot-wheels,
by causing a quantity of back-water to be hfted, or sucked
up, by the ascending inverted bucket, when it first leaves
the water. This difficulty is remedied, by making a few-
small holes, near the base of the bucket, and communi-
cating with the next bucket. Through these, the air will
enter, and prevent the suction. It is true, that, when on
the descending side, these holes will allow the escape of
some w^ater ; but, as this water only flows from one buck-
et to the next, its effect is inconsiderable, when compared
with the advantage gained. Air, as Professor Robison
observes, will escape through a hole, about thirty times
faster than water, under the same pressure.
With respect to variations in the fall, the same writer
remarks, that, since the active pressure is measured by
the pillar of water, reaching from the horizontal plane,
where it is delivered on the wheel, to the horizontal plane,
where it is spilled by the wheel, it is evident, that it must
be proportionate to this pillar ; and, therefore, we must
deliver it as high, and retain it as long, as possible. This
maxim obliges us to use a wheel, whose diameter is equal
to the whole fall. We shall not gain anything by em-
ploying a larger wheel ; for, although we should gain by
using only that part of the circumference, where the
weight will act more perpendicularly to the radius, we
shall lose more, by the necessity of discharging the water,
at a greater height from the bottom.*
Chain Wheel. — When there is a very small supply of
* JNIechanical Philosophy, vol. ii. p. 600.
On this subject, Dr. Brewster remarks, that, if we employ a wheel,
the diameter of which is higher than the fall, we may take advantage
of any casual rise of the water, above its usual level, and, by a partic-
ular form of the delivering sluice, introduce the water, higher upon the
wheel, and thu? actually increase the height of the fall
CHAIN-WHEEL.
89
water, falling from a very great head, the double overshot-
wheel, with a chain of buckets, is a valuable machine.
This wheel is represented in Fig. 150, where two rag-
Fig. 150.
wheels are placed, one at top, and the other at bottom,
and a series of buckets are fixed to an endless chain, the
links of which fall into notches in the circumference of
the rag-wheels. The water, issuing from the mill course,
is introduced into the buckets, on one side, at top. The
descent of the loaded buckets, on this side, puts the rag-
wheels in motion, and the power is conveyed from the
shaft of the upper wheel, to turn any kind of machinery.
When the buckets reach the bottom, they allow the water
to escape ; and, ascending empty, on the opposite side,
they again return to the spout, to be filled as before. In
this machine, the buckets have, in every part of their
path, the same mechanical efiect to turn the wheels, and
they do not allow the water to escape, till they have
reached almost the lowest part of the fall.
This species of wheel possesses another advantage,
namely, that, by raising the lower wheel, and taking out
two or three of the buckets, it may be made to work,
when there is such a quantity of back-water, as would,
otherwise, prevent it from moving.
Dr. Robison has described a machine, of this kind, in
which plugs, or horizontal float-boards, are fixed to a chain.
90 MOVING FORCES USED IN THE ARTS.
On the descending side, these plugs pass through a tube,
a Htile greater in diameter than that of the floats ; and the
water, acting upon these floats, as it does in the case of
a breast- wheel, gives motion to the two rag-wheels.
In regard to the most advantageous velocity to be pro-
duced, with a given quantity of water, in an overshot-
wheel, various mathematicians have concluded, that th^
slower a wheel moves, the greater is its power of perfor
mance. But the experiments of Mr. Smeaton lead to
the conclusion, that, in practice, there is a limit of veloc-
ity, and that overshot- wheels do most work, when their
circumference moves at the rate of about three feet in a
second.
Undershot Wheel. — An undershot water-wheel, is a
wheel furnished with a series of plane surfaces, called
floats, or float-boards, projecting from its circumference,
for the purpose of receiving the impulse of the water,
which is delivered by a proper canal, with great velocity,
upon the under part of the wheel. A wheel of this kind
is represented in Fig. 151.
Fi2. 151.
When an undershot-wheel is put in motion, by a stream
of water striking against one of its float-boards, in a direc-
tion at right angles with the radius, the action of the water
will diminish, as the velocity of the wheel increases, till,
at last, the momentum of the water, or of the accelerating
force, is just equal to the momentum of the resistance, or
of the retarding force. The motion of the wheel will
then become uniform.
By calculation, it appears that a machine, thus driven
UNDERSHOT-WHEEL. 91
oy the impulse of a stream, produces the greatest effect,
or does most work in a given time, when the wheel moves
with one third of the velocity with which the water moves.*
But, in practice, this rule is liable to some variation ; for
the water does not escape, as soon as it has given its im-
pulse, but is confined by the channel, for some time, and
acts with a variety of influences. In Mr. Smeaton's ex-
periments, which are cited as authorities by most writers,
since his time, it was found, that an undershot- wheel,
when working to the greatest advantage, had a velocity,
which varied from one third to one half the velocity of
the stream ; and that, in great machines, it was nearer to
the latter of these limits, than the former.
It is advantageous, that the size of undershot-wheels
should be as great as circumstances will permit, and it
ought never, says Dr. Brewster, to be less than seven
times the natural depth of the stream, at the bottom of
the course. f In regard to the best number of float-boards,
a difference of opinion has prevailed ; but it is now gen-
erally admitted, that the more float-boards a wheel has,
the greater and more uniform will be its effect.^ Ac-
cording to the experiments of Bossut, it appeared, that
a wheel with forty-eight float-boards produced a greater
effect, than one with twenty-four ; and the latter, a greater
effect, than one with twelve. Smeaton's experiments
justify the same conclusion, though he found, that, on
adapting to the wheel a circular sweep of such length,
that one float-board entered into the curve, before anoth-
er left it, the effect came so near to the former, as not to
give any hopes of advancing it, by increasing the num-
ber of floats, beyond twenty-four, in the wheel experi-
mented on.§
In regard to the position of the float boards, they
should not be in the direction of the radius, but inchned
from it slightly, backwards. From the experiments of
* Playfair's Outlines of Natural Philosophy, rol. i. p. 214 ; and Ro
bison, 622.
t Ferguson's Mechanics, vol. ii. p. 17.
t Gregory's Mechanics, vol. i. p. 462.
§ Ibid. p. 476.
92 MOVING FORCES USED IN THE ARTS.
Deparcieux and Bossut, it appears, that there is a very
sensible advantage gained, by inclining the float-boards to
the radius of the wheel, about twenty degrees, so that
the lowest float-board shall not be perpendicular, but have
its point turned up the stream, about twenty degrees.
This inchnation causes the water to heap up along the
float-board, and act by its weight.* The floats should,
for this pui'pose, be made much broader, in the direction
of the radius, than the vein of water, which they inter-
sect, is deep. Another advantage, attending this obli-
quity of the floats, is, that they are less resisted, when
they rise out of the water.
The best way of delivering the water, on an undershot-
wheel, in a close mill-course, according to Dr. Robison,
is to let it shde down a very smooth channel, without
touching the wheel, till it arrives near the bottom, at
which place the wheel should be exactly fitted to the
course. The floats should be broader than the depth
of the water, so as never to be wholly immersed, but al-
lowing the intercepted water to heap up against them.
If the bottom of the course be an arc of a circle, hav-
ing a greater radius than that of the wheel, the water,
which sHdes down, will be gradually intercepted by the
floats, or strike upon more than one at a time. In this
country, it is often the practice, to admit the water, direct-
ly, from the bottom of a pond, or reservoir, instead of
causing it to glide down a separate channel, from near the
top ; and this method is found very effectual.
Back Water. — The back-w^ater, or tail-water, is that
portion which has passed by the wheel. This portion is
not only useless, but, in most cases, injurious ; since, by
its inertia and weight, it resists the escape of the floats
and empty buckets, in their passage upward. Its effect
is increased, in times of floods, or freshets, so that it is
often necessary to place wheels higher than they other-
wise would be, to provide against it. A method of get-
ting rid of back-water, in times of flood, has been invent-
ed by Mr. Perkins, in this country, and Mr. Burns m
* Robison's Mechanical Philosophy, vol. ii. p. 625.
BESANT'S WHEEL.
93
Scotland. It consists in a separate passage, by which a
current of water is taken from the mill-lead, or flume,
Fig. 152.
as at A, in Fig. 152, and passes, with great rapidity,
under the wheel, and thence under the flooring, at B.
This rapid current has the effect to take ofi', and carry
away, the back-water from beneath the wheel, while it is
prevented from returning, by the force of the same cur-
rent, and the barrier, at C. The water, which is expend-
ed to maintain this current, is no more than would run
over the waste gate, in a time of freshet.
BesanVs Wheel. — To diminish the retardation occa-
sioned by back-water, Mr. Besant has invented a wheel,
in which the floats are placed obhquely in a double row,
as in Fig. 153, where the wheel is represented as seen
edgewise.
Each pair of floats foims an acute angle,
open at its vertex. By this construction, the floats es-
cape more gradually, and with less resistance, from the
back-water, and likewise the resistance of the atmosphere
94
MOVING FORCES USED IN THE ARTS.
is prevented, by the admission of air, at the open angle
of the floats.
LambtrVs Wheel. — As water acts most advantageously
upon undershot-wheels, when the floats are perpendicular
to the surfaces of the stream, it has been attempted, in
difllsrent ways, to keep them always in a vertical posi-
tion. In the method proposed by Mr. Lambert, the floats
are hung upon hinges, or pivots, at the extremities of th?
spokes, and are kept in a vertical position by a large iro-
ring, which is suspended from the lower extremities of
the whole, and is allowed to pass, during the revolution,
through a slit in the middle of each float. In Fig. 154,
is a view of one side of the wheel, with the ring attached.
A, is the centre of the wheel ; BD, are spokes, or arms,
of the water-wheel ; CD, are the float-boards, which
are here seen edgewise. EE, is a large iron ring, con-
nected by joints to the lower extremity of all the float-
boards, and serving, by its weight, to keep them in a ver-
tical position. This wheel is, probably, too complicated
for common use. The iron ring is kept from moving side-
ways by guides, or friction-wheels, placed at each side.
Breast Wheel. — The breast-wheel is intermediate be-
tween the overshot, and undershot, wheels, having the
water delivered upon it, at about half its height, or at the
HORIZONTAL WHEEL.
95
level of its axis. In breast wheels, in England, buckets
are not commonly employed, but the float-boards are
fitted accurately, with as little play as possible, to the
mill course, so that the water, after acting upon the float-
boards, by its impulse, is detained between them in the
mill course, and acts, by its w^eight, till it reaches the low-
est part of the wheel. A breast-wheel is represented in
Fig. 155, as it is often constructed in this country, with
buckets, instead of floats, and with a part of its circum-
ference fitted to the mill course, or apron.
Fig. 155.
Horizontal Wheel. — A horizontal wheel, with obhque
floats, sometimes called, in this country, a tub-wheel, is
turned by a current of water, discharged against the floats,
in the manner represented in Fig. 156. This method is
Fig. 156.
said to be in common use on the continent of Europe,
and but seldom employed in England. It is a disadvan-
tageous mode of applying; power, and is only recom
96
MOVING FORCES USED IN THE ARTS.
mended in corn-mills, by its simplicity ; the millstones be-
ing turned directly by the axis of the water-wheel, with-
out the intervention of other wheels, or gearing. In the
same manner, another kind of tub-wheel^ which is a sort
of inverted cone, furnished with spiral floats on its inside,
is made to revolve horizontally, by discharging into it a
current of water, from above.
Barker^s Mill, — This machine, which is also some-
times called Parent'^s mill, is driven by an apphcation of
the force of water, different from any of those which have
been already described. This apphcation consists, not
in the direct use of the weight, or impulse of water, but
in that of its reaction, or counter pressure. The princi-
ple of this simple machine may be seen, by inspecting
Fig. 157, where CD, is a revolving, vertical tube, carry-
ing a millstone, [m,] on the upper part of its axis. At th^
bottom of this tube, is a horizontal tube, AB, at the ex-
tremities of which, are two apertures, A and B, opening
in opposite directions. A stream of water is introduced
from the mill course above, and flows out at the apertures,
at A and B, and, in this way, keeps up a continued hori-
zontal rotary motion, around the axis, [Dm.]
Fig. 157.
In order to understand how this rotary motion is pro-
duced, we may suppose the apertures to be shut, and the
WIND-POWER. VERTICAL WINDMILL. 97
tube, CD, filled with water. The area of the apertures,
A and B, will then be pressed outward, by a force, equal
to a column of water whose height is CD, and whose base
is equal to the area of the apertures. Every part of the
tube, AB, sustains a similar pressure ; but, as these pres-
sures are balanced, by equal and opposite pressures, the
machine remains at rest. But, when the aperture, at B,
is opened, the pressure at that place is removed, and,
therefore, the arm will be carried round, in a direction
opposite to that of the aperture, by a pressui'e which is
due to the height of the column, and area of the aperture.
The same thing happens with the other arm, and the two
pressures carry round the vertical axis, in the same di-
rection.
An Improvement has been made in Barker's mill, by
dispensing with the tube, CD, retaining only its axis ;
and introducing the water, on the under side of the trans-
verse tube, at D. For this purpose, the water is brought
down from the reservoir at E, by a separate passage, and
introduced, at D, through a water-joint, which suffers the
arras of the tube to revolve, without much loss of water.
Such a passage is represented by the shaded part, EFD.
The upward pressure of the water may be made to sup-
port a great part of the w^eight of the machine.
WIND-POWER.
Currents of water, being hmited in magnitude, can be
confined, in their action, to one side of a wheel. But it
is not easy to do the same, with currents of wind, on ac-
count of their indefinite magnitude, and the diificulty of
screening one half of the wheel, advantageously, from their
action. It is, therefore, common, to employ vertical wind-
mills, having a number of sails, placed obliquely to the
wind, and turning on a horizontal axis which is parallel
to the wind, or nearly so. The action of the wind, in this
case, is resolved into two forces ; and, since the sails can-
not obey the first, by moving in the direction of the wind,
they obey the second, and move at right angles, with it.
Vertical Windmill. — The common windmill has, usu-
ally, four sails, and, sometimes six or eight. The power
II. 9 XII.
93 MOVJ^'G FORCES USED IN THE ARTS.
of these sails, to turn their axis, depends, when other thhrgs
are equal, upon their degree of obliquity in regard to the
wind. The angle, which is most effectual for giving mo
tion to the sails, from a state of rest, is an angle of thirty-
five and one third degrees with the weather, or with the
plane in which the sails revolve.* But the angle, which
produces the greatest action upon a sail at rest, is not the
most effectual, when a sail is in motion. As the motion
ncreases, the action of the wind diminishes, and, in or-
der to preserve this action, the sails require to be brought
nearer to the wind. And, since each part of the sail, in
revolving, has a different velocity, those parts which are
nearest the circumference, being swiftest, are not acted
upon so powerfully by the wind, as those which are nearer
the centre ; on which account, it is useful to give the sails
a shght spiral curvature, so as to make the angle with the
w^eather, at the extremity of the sail, less than it is at the
centre. When, however, the sails are perfectly plane^
it is advantageous, according to Mr. Smeaton, that the
angle of the sails with the weather should be eighteen
degrees, or less ; in other words, that their angle with the
axis should be seventy-two degrees, or more. The ve-
locity of the sails, in this case, at their outer extremity,
is often found to be more than twice that of the wind.
Adjustment of Sails. — On account of the inconstant
nature of the motion of the wind, it is necessary to have
some provision, for accommodating the resistance of tlie
sails, to the degree of violence with which the wind
blows. This is commonly done, by clothing and unclo-
thing the sails ; that is, by covering, with canvass, or thin
boards, a greater or smaller portion of the frame of the
sails, according to the force of the wind, at different
times. A method has been devised, for producing the
same effect, by altering the obhquity of the sails ; and
windmills have been so made, as to regulate their own
adjustment, by the force of the wind. If we suppose a
wmdmill, or wind-wheel, to consist of four arms, and that
the sails were connected to these arms, at one edge, by
* Determined by Parent. See Brewster's Ferguson's Mechanics,
vol. ii. p. 69.
ADJUSTMENT OF SAILS. 99
means of springs, the yielding of these springs would al-
low the sails to turn back, when the wind should blow
with violence ; and their elasticity would bring thera up
to the wind, whenever its force abated. This effect has
been produced by a weight, acting on the sails, through a
series of levers. A loose iron rod, passing through the
centre of the axle of the wind-wheel, receives the action
of the weight, at one end, and communicates it to the sails,
at the other. '
Sometimes, a governor, like that described on page
77, is used, to regulate the velocity of windmills, which
are built for grinding, by increasing the supply of corn to
be ground, or of work to be done, whenever the force
of the wind increases. The governor is also applied,
in a very ingenious manner, to furl or unfurl a portion of
the sails, thus accommodating them to variations of the
wind.
As it is necessary that a windmill should face the wind,
from vhatever point it blows, the whole machine, or a
part oi it, must be capable of turning horizontally. Some-
times, the whole mill is made to turn upon a strong verti-
cal post, and is, therefore, called a post-mill ; but, more
commonly, the roof,-or head, only, revolves, carrying with
it the wind-wheel and its shaft, the weight being supported
on friction rollers. In order that the wind itself may
regulate the position of the mill, a large vane, or weather-
cock, is placed on the side which is opposite the sails,
thus turning them always to the wind. But, in large mills,
the motion is regulated by a small supplementary wind-
wheel, or pair of sails, occupying the place of the vane,
and situated at right angles with the principal wind-wheel.
When the windmill is in its proper position, with its shaft
parallel to the wind, the supplementary sails do not turn.
But, when the wind changes, they are immediately brought
into action, and, by turning a series of wheel-work, they
gradually bring round the head, to its proper 'position.
As the resistance, occasioned by the side of the build-
ing, makes a difference in the force of the wind upon the
upper and under sails, it is common to incline the sails,
sind their axis, in such a manner, that the lower sails shall
100 MOVING FORCES USED IN THE ARTS.
be further from the building, than they would be, if in a
vertical position.
Horizontal Windmill. — This name is given to those
windmills which turn on a vertical axis. Various meth-
ods are employed in their construction, in most of which,
the wind acts by its direct impulse, as in an undershot
water-wheel. In the most common forms, the sails, like
float-boards, present their broadside to the wind, on the
acting side of the wheel, but are folded up, or turned
edgewise, on the returning side. These wheels, however,
are found to be greatly inferior to the vertical windmill,
in the amount of work w4iich they are capable of perform-
ing, and, at the present day, they are little used.
As w^ind is the most uncertain of all the moving agents,
and fails, totally, in times of calm, it is not common to
depend upon this power, in large works, provided other
moving forces can be obtained. The steam-engine has,
in many cases, superseded it ; but it is still used, in cer-
tain places, for grinding corn, pum.ping water, and driving
inferior machinery. Upon the ocean, it is a locomotive
agent, of incalculable importance.
"^ STEAM-POWER.
Steam. — The power of steam depends on the tendency
which water possesses, to expand into vapor, when heated
to a certain temperature. Many other substances, and,
perhaps, all, have the same tendency ; and those which
are volatile, at low temperatures, might, doubtless, be
made the sources of moving power, in the arts. But,
since water, which is the most cheap and abundant of
these substances, fortunately possesses, also, the greatest
number of requisites for an expansive agent, it is not like-
ly to be superseded by any other material.
When water is converted into steam, it expands to
about one thousand seven hundred times its original vol-
ume,* so that a cubic inch of water furnishes about a
cubic foot of steam, at two hundred and twelve degrees
* One thousand six hundred and thirty-three times, according to
Gay-Lussac. See Ure's Dictionary, article Caloric. One thousand
seven hundred and eleven times, according to Tredgold.
STEAM-POWER. 101
of Fahrenheit, under the common pressure of the atmos-
phere. Water cannot, however, be converted immedi-
ately into steam, by the application of a boiling tempeia-
ture, but requires a certain period, to effect its volatiliza-
tion. This period is about six times as great, as that
which is necessary to raise it from the freezing to the
boiling point, supposing the supply of heat to be uniform.
The amount of heat, which is absorbed, or rendered
latent, by the conversion of water into steam, is about
nine hundred and fifty degrees.*
The power of steam, to produce motion in other bodies,
depends upon the increase of its own volume ; and what-
ever body resists this increase, will be acted upon by a
force, proportionate to the elastic powe** of the steam, and
the circumstances under which the resistance is made.
In a vessel boiling in the open air, we are not sensible of
the magnitude of this force, because the steam, and the
resisting medium, against which it acts, are both invisible.
But, when we consider that the steam, when first gener-
ated, has to lift off from the water, before it can assume
its elastic form, the weight of the superincumbent atmos-
phere, and that this weight, in the atmospheric column
which presses on a vessel, only two feet in diameter, is
equal to several tons, we may easily conceive of the force
which attends this expansion.
Furthermore, since steam has the property of imme-
diately condensing into water, as soon as its temperature
is reduced below two hundred and twelve degrees, it fol-
lows, that the atmospheric weight which has been lifted,
by the formation of the steam, will immediately fall, when
the steam condenses ; and with a force, equal to that by
which it was raised. This furnishes an indirect, or sec-
ondary, application of the power of steam.
But the powers of steam are not Hmited by the effects
which it produces, at the common boihng temperature.
If steam be separated from the contact of water, and
exposed to a further increase of temperature, it will con-
tinue to expand, by the law which governs the increase
* Nine hundred and fifty, according to Watt. Nine hundred an^
sixty-seven, Ure.
9*
f02 MOVING FORCES USED IN THE ARTS.
of all gaseous bodies, and will double its volume, once,
for every four hundred and eighty degrees of Fahrenheit's
thermometer.* And, furthermore, if water itself be en-
closed in strong vessels, and thus heated, its expansive
force will be prodigiously greater than that of steam alone ;
since every particle of the water tends to generate steam,
of high temperature, and to occupy the space which is
due to such steam. In a common boiler, containing wa-
ter and steam, each addition of caloric causes a fresh
portion of steam to rise, and to add its elastic force to
that of the steam previously existing, so that an excessive
pressure is soon exerted against the inside of the vessel,
if the augmentation of heat has been considerable. At
two hundred and twelve degrees, Fahrenheit, steam has
an elastic force, equal to the pressure of the atmosphere.
If it be farther heated, in contact with water, it will have
a force, equal to that of two atmospheres, at about two
hundred and fifty degrees ; of four atmospheres, at two
hundred and ninety-three degrees ; and of eight atmos-
pheres, at three hundred and forty-four degrees. These
are the results, in round numbers, of Mr. Southern's
experiments ; and they are nearly confirmed, by those of
Drs. Robison and Ure.f
At temperatures below two hundred and twelve de-
grees, steam has still a certain elastic force, which dis-
covers itself, whenever the pressure of the atmosphere is
taken off. Thus, its elastic force, at one hundred and
eighty degrees, is equal to about half an atmosphere ; and
it has some force, at all temperatures above the freezing
point.
Steam expands in all directions, alike, and is useful, as
a moving agent, only by its pressure. It cannot, like water
and wind, be made to act advantageously by its impulse,
* Ure's Dictionary of Chemistry, Art. Caloric and Gas.
1 The recent and elaborate experiments of Messr?. Arago and Du-
Icng, have corrected these results, and carried the scale as high as fifty
atmospheres. Thus, an elastic force, equal to the pressure of twenty
atmospheres, is produced by a heat of about four hundred and eighteen
degrees, Fahrenheit, and one of fifty atmospheres, by five hundred and
ten degrees.
APPLICATIONS OF STEAM. 103
m the open air ; for the momentum of so hght a fluid, un-
less generated in vast quantities, would be inconsiderable.
Some of the earliest attempts, however, at forming a
steam-engine, consisted in directing the current of steam,
from the mouth of an eolipile, against the vanes, or floats,
cf a revolving wheel.* In order that the pressure of
steam may be rendered available, in machinery, the steam
must be confined within a cavity, which is air-tight, and
so constructed, that its dimensions, or capacity, may be
altered, without altering its tightness. When the steam
enters such a vessel, it enlarges the actual cavity, by caus-
ing some movable part to recede before it, and, from this
movable part, motion is communicated to machinery. A
hollow cylinder, having a movable piston, accurately fitted
to its bore, constitutes a vessel of this kind. It was used,
more than a century ago, by Newcomen ; and, as it is
found to combine more advantages, than any other kind
of arrangement, for motion, its use has never been super-
seded The piston, thus employed, has a reciprocating
motion, which is converted, when necessary, into a rotary
one, by the appropriate mechanism.
Applications of Steam, — The pressure of steam is
capable of being applied to use, in three different ways ;
and these modes have given rise to some of the most im-
portant varieties of the steam-engine. The three methods
which are used, for obtaining power from steam, are, 1.
By condensation, as in the atmospheric engine. 2. By
generation, as in the simple high-pressure engines. 3.
By expansion, as in Woolf's engine. Watt's expansion
engine, and some others. These methods have been il-
lustrated, by Mr. Tredgold, by a figure like that on page
104. Suppose a cylindric vessel, ABCD, to be plac-
ed in a vertical position, with a given depth of water in
the bottom, and an air-tight piston, above the water, bal-
anced by a weight, D, equal to its own vveight and fric-
tion. In this state, let heat be applied to the base, AC ;
then, as the water becomes converted into steam, of slight-
ly greater force than the atmospheric pressure, the piston
* Such was the engine of Branca, in the beginning of the seven-
feenth century.
104
MOVING FORCES USED IN THE ARTS,
Fig. 158.
\0
will rise, till the whole water is in a state of steam. It
must be observed, however, that the generation of this
steam, which is of atmospheric elastic force, affords no
available power, but is simply sufficient to balance the
column of atmospheric air, and exclude it from a given
height of the cylinder.
By Condensation. — In the state of things just describ-
ed, if the steam be suddenly condensed into water, by the
application of cold, it is obvious, that the piston will be
driven downward, with a force, equal to the weight of the
atmosphere which presses on the piston, and through a
distance, equal to that which the piston had been raised,
by the generation of steam. It follows, that the power
of steam, which is of atmos^^heric elastic force, is, when
speedily condensed, directly proportionate to the space
which it occupies. If the temperature of this steam be
raised above two hundred and twelve degrees, it will oc-
gener'ation of steam. lOd
cupy a larger space, the increase being equal to the ex-
pansion of steam, by the given change of temperature.
But a quantity of heat, nearly equivalent to the increase
of volume, will be absorbed ; and hence, says Mr. Tred-
gold, the effect of a given quantity of fuel would not be
Increased by the expedient.*
By Generation, — Suppose the same cylinder and ap
paratus to have heat applied to its base, with only the
difference of the piston being loaded with a given pres-
sure per inch of its area. The generation of the steam
will raise the loaded piston ; but the height, through which
it will be raised, will be less than if it were not loaded.
The steam having to act in opposition, both to the pres-
sure of the atmosphere, and the load^Dn the piston, the
space it will occupy will be in the inverse ratio of the
pressures which oppose it, supposing the steam of atmos-
pheric elastic force to have been of the same temperature.
Thus, if the load on the piston be equal to twice the at-
mospheric pressure, the piston will be raised only one
third of the height ; but, on rapid condensation, it de-
scends with three times the pressure ; and, therefore,
whether the steam be generated of atmospheric elastic
force, or of a greater force, the power it affords, by gen-
eration and condensation, is the same, at the same tem-
perature, and this power is directly as the elastic force
of the steam, multiplied by the space it occupies, sup-
posing that the motion of the piston is rectilinear.
But if, as in the last case, a loaded piston be raised,
and then a valve be opened, which allows the steam to
escape, the whole power gained will be equal only to the
weight raised, descending from the height to which it was
raised ; and the power, which would have resulted from
condensation, will be lost, and the loss is equal to the
pressure of the atmosphere, acting through the height, to
which the piston w^as raised by steam. This is the na-
ture of the common high-pressure steam-engine. It is
obvious, that the greater the elastic force of the steam,
the less is the proportionate loss, by neglecting to con-
* Tredgold, on the Steam Engine, p. 157 — 159.
106 MOVING FORCES USED IN THE ARTS.
dense it under these circumstances ; but it may be re-
marked, that, unless the valve aperture be equal to the
diameter of the cylinder, the steam cannot escape at the
necessary rate, without part of the load acting to expel
it ; and so much more of the effective force will, of
course, be lost. The effective power is as the space the
steam occupies, multiplied by the excess of elastic force
above the atmospheric pressure.
By Expansion. — Retaining the same loaded piston, let
it be raised, by the conversion of a given quantity of water
into steam, to the height which corresponds to the load
and temperature. Then, if the load on the piston be
wholly removed, at that height, the steam will raise the
piston, by expancflhg, till it becomes nearly of the same
elastic force as the atmosphere, and its condensation will
produce the same effect, as if the steam had been gener-
ated of atmospheric elastic force, at first. Consequently,
the effect, in raising the load on the piston, is wholly ad-
ditional, and the joint effect of a high-pressure and con-
densing engine is produced, by the same steam. Hence,
by this combination of effect, the power of steam, of high
elastic force, will be nearly doubled.
This is not, however, the mode by which steam can
be applied with the greatest advantage ; for, instead of
removing the load on the piston, wholly, at the height to
which it was raised, by the generation of the high pres-
sure steam, a part of it may be removed, and then the
steam would expand, to a height depending on the por-
tion of the load removed ; at that height, remove a second
portion, and so on, successively, till the steam becomes
of atmospheric elastic force. In this case, as far as the
load was raised, in parts, by the expansion of the steam,
the effect is greater than in the preceding combination.
This illustrates the principle of the high-pressure expan-
sion engines of Evans, Woolf, and some others.
Again : let the piston be raised, unloaded, as in the first
case, by the conversion of a certain quantity of water into
steam of atmospheric elastic force. When the piston is
at that height, add a weight, equal to half the atmospheric
pressure, to the line passing over the pulley. Then the
STEAM-ENGINE. 107
elastic force of the steam being unbalanced, the piston
/ would rise, till that elastic force would be half the atmo-
spheric pressure, or till the piston would be at double its
former height. Now, suppose the steam to be condensed,
and the weight removed from the pulley, at the same in-
stant. Then, the power of the descent, after deducting
the power added to produce the ascent, will be one half
iijore than it would have been, by simply condensing steam
of atmospheric elastic force. This illustrates the prin-
ciple of the expansion engines of Hornblower and Watt ;
and it differs from the principle of Woolf, in using steam
only of low pressure. The weight, added to the line pas-
sing over the pulley, is introduced here, merely to ex-
emplify the mode of applying a portion of the excess of
power, which is accumulated in the fly-wheel, in one part
of the operation, to assist the machine, through the rest.
It has been assumed, that steam, at least of atmosphe-
ric elastic force, was generated ; but thi§ is not a necessary
condition, for it frequently occurs, that engines work with
steam of less elastic force. The same mode of illustra-
tion will show whence this happens. Let half the pressure
of the atmosphere, on the piston, be balanced by a weight
over a pulley. Then, on the application of heat, steam
of half the atm.ospheric elastic force would be generated,
and raise the piston to double the height that it would be
raised, in common cases, by steam, capable of supporting
the atmospheric pressure. Consequently, on its being
condensed, the descending force will be half the atmos-
pheric pressure, acting through double the height ; and
the steam produces the same effect, as before.
The foregoing methods of the application of steam will
be found apparent, in the different forms of the steam-en-
gine, in which they have been called into use.
The Steam Engine. — The steam-engine is a machine,
by which the power, derived from steam, is converted to
practical use. It has occupied the attention of philoso-
phers and artists, for more than a century, and is now
brought to so great a degree of perfection, as, in the opin-
ion of many scientific men, to leave little probability of
tts further improvement. Whether viewed with reference
108 MOVING FORCES USED IN THE ARTS.
to the great skill which has been employed, in perfecting
it, or the importance and extent of its application, it may
justly be viewed as the noblest production of the arts, in
modern times. For acquiring a clear conception of the
steam-engine, as it is now commonly constructed, it will
be useful to consider, first, the boiler^ in which the power
is generated, and, second, the engine, in which it is di-
rected, and apphed to use.
Boiler. — On account of the gradual rate at which wa-
ter boils away, it is necessary, in most engines, to keep a
large quantity constantly heatecj, to afford steam with
sufficient rapidity for its consumption by the engine. This
water is enclosed in a strong, tight, vessel, called the
boiler, which is made of iron, or copper, and rests in
contact with a furnace. It is requisite, that a boiler should
be of sufficient strength, to resist the greatest pressure
which is ever liable to occur, from the expansion of the
steam. It must also offer a sufficient extent of surface
to the fire, to insure the requisite amount of vaporization.
In common low-pressure boilers, it requires about eight
feet of surface of the boiler to be exposed to the action
of the fire and flame, to boil off a cubic foot of water, in
an hour ; and a cubic foot of water, thus converted into
steam, is equal to a one-horse power.*
The strongest form for a boiler, and one of the earliest
which was used, is that of a sphere ; but this form is the
one which offers least surface to the fire. The figure of
a cylinder is, on many accounts, the best ; and it is now
extensively used, especially for engines of high pressure
It has the advantage of being easily constructed from
sheets of metal, and the form is of equal strength, except
at the ends. In such a boiler, the ends should be made
thicker than the other parts. The furnace is so con-
structed, that the flame and hot smoke may pass undei
the whole length of the boiler, and afterwards around both
its sides, before escaping to the chimney.
In what are caWed flue-boilers, a cylindrical furnace is
placed within a cylindrical boiler, so that the fuel is sur-
* See Tredgold, on the Stean-. Engire, with the following correction,
p. 124, Ime 2, from the bottom For steam, read water
EOILER.
109
rounded by water, on all sides, and communicates to it
nearly all its heat, except the portion which passes up the
chimney.
In large engines, which are of low pressure, the form
of the boiler, which was used by Mr. Watt, still contin-
ues to be employed, particularly in England. In this
boiler, the upper half is a semi-cyhnder, while the lowei
half is nearly rectangular, with the under side concave, so
that a cross section would nearly resemble a horse-shoe.
This boiler is less strong than those of a cvhndrical form,
but it offers a larger surface to the fire, without occupy-
mg much more space. A boiler of th'": kmd, as it is fit-
ted up in large engines, with append? Z'^:^ for regulating its
Fig. 159.
Ml
no MOVING FORCES USED IN THE ARTS.
own fire, water, and steam, is represented in the figure,
[159,] on the preceding page. A part of the furnace is
supposed to be taken away, to bring the boiler into view ;
and, also, a portion of the boiler is removed, to show its
inside.
Jlppendagcs. — In the figure above referred to, BBBB,
is the boiler, made of thick sheets, or plates, of rolled
iron, strongly riveted together, a part of which are remov-
ed, to show the interior. It is supposed to be half full of
water, at the boiling temperature. C, is the steam-gauge^
the object of which is to determine the degree of pressure
acting within the boiler. It is a bent iron tube, or invert-
ed syphon, one end of which communicates with the boil-
er, and the other end with the atmosphere. The tube js
partly filled with mercury, and, as the pressure of the
steam increases, the mercury will be driven outward, and
will rise in the external leg of the syphon. As the height
of the column of mercury cannot be seen, the tube being
opaque, a small wooden stem is made to float in the tube,
with its end projecting by the side of a graduated scale.
Every inch in height, which the stem rises, shows a dif-
ference of two inches in the two surfaces of the mercury
in the tube, and indicates a pressure of about a pound,
upon every square inch of the inner surface of the boiler.
And, as low-pressure engines are seldom worked with
more than three or four pounds to the square inch, the
mercury seldom rises higher than three or four inches, in
such engines. In high-pressure engines, the mercurial
gauge is not so easily applied ; for these engines are fre-
quently worked, at a pressure of several atmospheres, and
each additional atmosphere requires an addition, of nearly
fifteen inches, to the column of mercury.
W, is a large opening, called the man-hole^ of sufficient
size to permit a man to enter the boiler, to clean or exam-
ine it. It is closed by a strong iron plate. D, is the
steam-pipe, which conveys the steam to the engine. It
is provided with a throttle-valve, which is a circular disc,
or partition, turning on an axis, and connected with the
governor, described on page 77. Its use is to regulate
the supply of steam, by closing the pipe, i the engine
STEAM-ENGINE APPENDAGES. ^ 111
goes too fast, or by opening it, if it is too slow. FF,
are the gauge-cocks^ which indicate the height of water
in the boiler. Their extremities stand at different depths,
in the boiler, one being below the surface of the water,
and the other above it. When the water is at the proper
height, one of these will emit steam, on being opened,
and the oiher will emit water. They are frequently plac-
ed on the end, instead of the top, of the boiler.
For keeping up a regular supply of water to the boiler,
a vertical tube, 6, called the feed-pipe, is used. Upon
Its top, is a small cistern, HHHH, which is kept full of
water, by a pump, worked by the engine. At the bottom
of this cistern, is a valve, E, connected to one end of the
lever, [a6.] At the other end of this lever, is a wire, [f/c,]
which passes through a steam-tight opening, at [c?,] and
supports a stone float, [c,] upon the surface of the water,
the stone being counterbalanced by a weight, at the valve,
[e.] When the w^ater lowers, in the boile*' -he stone float
descends, and, by acting upon the lever, [u-u J opens the
<^alve, [e.] Water immediately flows in, from the cistern,
and continues to do so, till the float rises, and shuts the
valve. It will be observed, that the column of water, in
the feed-pipe, must be sufficiently high to counterbalance
the pressure of steam, in the boiler. On this account,
it can not be applied in high-pressure engines, without
making it of a very inconvenient height. In these en-
gines, therefore, water is supplied to the boiler, by a
small forcing pump, worked by one of the reciprocating
parts of the engine ; and it is frequently heated, before
being pumped in, that it may not check the production of
steam.
For the purpose of regulating the fire, the feed-pipe
is furnished with an iron bucket, O, hung by a chain,
which passes over two pullies, PP, and is attached by its
other extremity to an iron damper. A, which commands
the chimney. When the steam in the boiler is urged to
too great an extent, it forces the water upward, in the
feed-pipe, and causes the iron bucket to ascend. This
lowers the damper into the smoke-flue, and, by thus
intercepting the current of air, checks the force of the
112 MOVING FORCES USED IN THE ARTS.
fire. In some boilers, the passage, which brings air to
the fire, is intercepted, instead of the smoke-flue.
To prevent the boiler from bursting, if, by accident,
the pressure of the steam should become too great for the
strength of the boiler, a safety-valve is provided, at S,
opening outward. It is kept down by a weight, so that
it cannot be raised," except by a greater force than that
which is required to work the engine. It is highly im-
portant, however, that it should not be liable to any other
weight, or encumbrance, than that which the engine re-
quires ; and, to prevent this danger, it is enclosed in a
case, which is kept locked. When the engine stops
working, or the steam is generated too rapidly for its ex-
penditure, the safety-valve rises, and the superfluous steam
rushes out, with a hissing noise.
Another safety-valve is also provided, which differs
from the preceding, in opening inwards. It is kept up
by a counter weight, on a lever, and its use is to prevent
the weight of the atmosphere from crushing in the sides
of the boiler, when the engine stops w^orking, and the
steam cools.
As boilers are usually proved, before being submitted
to use, the accident of bursting does not happen, from a
general want of strength, unless the safety-valve be over-
loaded. It is most likely to happen, either from neglect,
in suffering the water to get too low, in some part of the
boiler, so that the metal is excessively heated, or else,
from the corrosion of the metal, in places, by oxidation,
after long exposure to the fire. If a sediment is suffered
to accumulate, to a considerable depth, on the bottom of
the boiler, it has the effect to exclude the water from con-
tact with the metal, so that the metal becomes hotter, and
is more rapidly oxidated, and even softened, by the heat
The violent explosions which have sometimes occur
red, projecting the contents and fragments of the boiler
to a great distance, have been rationally accounted for,
by supposing that certain parts of the metal, through neg-
lect, become heated to a high temperature, and, that por-
tions of water, being suddenly brought into contiguity with
them, produce steam, of which the initial elastic force is
STEAM-ENGINE APPENDAGES. 113
extremely great. In this case, the boiler may burst, be-
fore the inertia of the water- or safety-valves, is over-
come ; and the stronger is the boiler, the greater may be
the explosion.
As a great number of lives have been lost by the ex-
plosion of boilers, particularly on board of steam-boats,
much attention has been bestowed on the means of pre-
venting such accidents. The principal attempts have
consisted, in a more accurate regulation of the safety-
valves, and in the introduction of plugs of fusible metal,
which melt, when the temperature is raised a little above
the boihng point of water, and thus suffer the steam to
escape. But absolute security has only been found, in
placing the boiler in such a situation, that, if it should
burst, it would occasion no injury to the passengers in
the boat. This is effected, by placing the engine in a
boat by itself, or by interposing a strong barrier between
the boilers, and the persons on board the boat. Mr.
Tread well has proposed to use the steam, at a pressure
not greater than that of the atmosphere, and to compen-
sate the loss of force, by an increase in the size of the
cylinder and piston.
Besides the forms of the boiler, already mentioned,
various others have been employed, such as combinations
of tubes, and other figures, intended to multiply surface,
for the purpose of raising more steam, from the same
amount of water, in a given time. They have been
applied in some high-pressure engines, but, in most ca-
ses, the simpler forms are preferred.* In Brathwaite and
Ericsson's engine, which has been apphed, with partic-
ular success, to propelling carriages on rail-roads, the hot
air of the furnace is forcibly drawn, in a circuitous flue,
through the boiler, by means of a revolving, fan-like ap-
paratus ; thus communicating to the boiler a greater quan-
tity of heat, in a given time, than could be obtained from
the common atmospheric draught.
* In Perkins's engine, a strong vessel, called a generator ^ is kept full
of water heated to a high temperature. Portion? of the water are suc-
cessively forced out ; and reliance is placed on the heat already in this
water, to produce from it the requisite amount of steam.
10*
114 MOVING FORCES USED IN THE ARTS.
Engine. — The steam being generated in sufficient
quantities in the boiler, it is next applied to use in the
working, or moving, part, which we have called the en-
gine. Of this engine, a great variety of forms and mod-
ifications have been proposed, and adopted, at different
times. A few of those, which are effectual in their prin-
ciple, and most extensively employed, will now be con-
sidered.
j^on- condensing Engine. — The simplest form of the
steam-engine is that of the non-condensing, commonly
called the high-pressure, engine. In this engine, the ap-
paratus for condensation is dispensed with, and the steam
is worked at a high temperature, and afterwards discharg-
ed into the open air. Of course, a part of the force of
the steam is expended, in overcoming the pressure of the
atmosphere, and the surplus, only, can be applied to drive
machinery. That this surplus may be sufficient to pro-
duce the requisite power, a pressure of thirty or forty
pounds, on a circular inch, above the atmospheric pres-
sure, is commonly kept up in these engines.*
The manner, in which the engine is made to operate,
fs, briefly, as follows. The steam, in escaping from the
boiler to the open air, is obliged to pass through the cyl-
inder, the cavity of which is closed, except where it com-
municates with the valves. By the opening and shut-
ting of these valves, the steam is made to enter the cylin-
der, alternately, at each end, and escape by the opposite
end. But, in doing this, its passage is always intercepted
by the piston ; so that, before it can escape, it must move
the piston from one end to the other of the cylinder.
The repetition of this movement gives motion to a beam,
or other alternating part, from which it is communicated,
by a connecting rod and crank, to a fly-wdieel, in the same
manner as is seen in the condensing engine, [PI. III.]
hereafter to be described. The figure, there represented,
may be considered as a non-condensing engine, if we re-
move from it the condenser, and its appendages, occupy-
ing the lower part of the plate. B, represents the boiler ;
^^, the pipe, which conveys the steam ; D, the cylinder ;
* See Tredgold, on the Steam Engine, p. 181.
CONDENSING ENGINES. 115
E, the piston; F, the beam; [A,] the crank; G, the
fly-wheel.
The different apparatus of valves, by which the entrance
and escape of steam is regulated ; also, the other appen-
dages of the engine, will be considered in another place.
In arranging the time of their opening and shutting, it is
usual to allow not quite all the steam to escape, at the
end of the stroke. A small portion is retained, to receive
the shock of the piston, and, by its elasticity, to destroy
its momentum, and cause it to recoil back, without loss
of force.
Non-condensing engines sometimes work by the gener-
ative force of steam, and, sometimes, by the generative and
expansive force. They are used in cases where simphc-
ity and lightness are required, as in locomotive engines ;
also, in situations where a sufficient supply of water, for
condensation, cannot easily be obtained. They are infe-
rior, in safety, to condensing engines ; yet, as they cost
much less at the outset, for the expense of building, they
are often preferred for small, or temporary, works. In
proportion to the high temperature at which the steam
is worked, great caution is necessary, in regard to the
strength and management of the boiler, in these engines.
Condensing Engines. — Engines of this class are fitted
up, with an apparatus for condensing the steam into water,
so that a vacuum, nearly complete, is formed in one part
of the cylinder, just before the stroke of the piston, into
that part, takes place. By this construction, the resist-
ance of the atmosphere is avoided ; and, thus, the power
of the engine, to perform work, is much increased. The
steam, also, is sufficiently powerful for use, at compara-
tively low temperatures ; and hence arises the increase of
safety which is found in Imc-pressure engines, a name giv-
en to those condensing engines, which are worked with
steam of moderate elastic force.
In the atmospheric engine^ invented by Newcomen, the
piston was raised by the steam, aided by a counter weight,
till it arrived at the top of the cylinder, which was left
perfectly open. A jet of v/ater was then admitted into
rhe bottom of the cylinder, which suddenly condensed
116 MOVING FORCES USED IN THE ARTS.
tlie steam, so that, a vacuum being formed, the piston was
driven down, by a force equal to tlie weight of the column
of superincumbent air. The water was now excluded by
a stop-cock, and the steam readmitted. The piston was
thus again raised, and the process repeated as before.
A great inconvenience attended this method, arising
from the circumstance, that the cylinder itself required to
be heated and cooled, at each stroke of t.ie piston, thus oc-
casioning great delay, and an mmecessary expense, both
of fuel, and of cold water. To remedy this evil, Mr.
Watt invented the separate condenser^ which is a strong
vessel, situated at a distance from the cylinder, but com-
municating with it by a pipe, so as to form with it a com-
mon cavity, without reducing, materially, its temperature.
Into this vessel, the jet of cold water is thrown, and, as
all the communicating pipes are governed by valves, or
cocks, the cyhnder, below the piston, is alternately filled
with steam, from the boiler, and emptied of steam, by the
condenser.
In the double-acting engine, invented by Mr. Watt,
the top of the cylinder was closed, and rendered air-tight,
the rod of the piston, only, passing through it. Thus,
the cylinder is divided, by the piston, into two cavities,
both communicating with the boiler, and both with the
condenser. By the aid of valves, an alternate communi-
cation is kept up, so that the steam, being alternately ad-
mitted at both ends, impels the piston, successively, in
both directions, while the condenser, at the same time,
destroys the resistance. In this engine, compared with
the single engine of Mr. Watt, which was previously in
use, a double quantity of steam is used, and a doubk
power exerted, in the same space and time.
Description. — In PL III., 's a view of a double-acting
steam-engine, nearly as constructed by Murray, and upon
the same general principles as those of Mr. Watt, vary-
ing, however, in the valves, and some other particulars.
A, represents the furnace, which is here shown in sec-
tion, as is also the boiler, above it, and all the principa\
cavities of the engine. The flame and hot smoke, after
passing underneath the boiler, for its whole length, return
DOUBLE-ACTING STEAM-ENGINE. 117
through the side passages, [c/c/,] before they are dischar-
ged into the chimney.
B, is the boiler, which, in this example, is of a cyhn-
drical form, a shape better adapted for strength, than that
I'epresented in Fig. 159. The appendages represented in
Fig. 159 arenot here repeated. Some of them, indeed,
are not used in steam-boats, and in small engines. The
boiler is commonly made of sheets of iron, strongly rivet-
ed together, and tightened by hammering. If intended to
contain salt water, the boiler is made of copper, to prevent
corrosion.
CCC, is the steam-pipe, which carries the steam from
the boiler to the cylinder, through the valve, I. It is made
of cast-iron, and its joints screwed together by flanges.
D, is the cylinder, communicating, by passages at the
top and bottom, with the valve, I. The cylinder is made
of cast-iron, and accurately bored, to make its inner sur-
face smooth and true.
E, is the piston, which, by its rod, [e,] gives an alter-
nating motion to the beam, [//,] about its centre, F, the
other end of which, by another connecting rod, [^,] gives
motion to the heavy fly-wheel, GG, by means of a crank,
[/i.] Thus, after the engine has begun to work, its power
is accumulated in the .fly-wheel, and a circular motion
may be communicated from it to any machinery.
H, is an eccentric circle, on the axle of the fly-wheel,
G. It gives motion through the medium of its levers,
[z6M' and yz^'] and the connecting rods, [Jiicxy, and;2:I,] in
a manner easily understood, by inspection, to the valve, I.
I, is a coffer-valve, capable of sliding up and down,
and having a cavity on the side next the cylinder. By
moving up and down, it opens and shuts the passages, ana
admits the steam, alternately, to each end of the cylinder ;
and, at the same time, forms a communication between
the opposite end, and the condenser.
W, is the governor, which regulates the speed of the
engine. It resembles the governor described in chap. XV.
but has its movable collar on the top, at [5.] It may be
turned by a band, from the axle of the fly-wheel, or placed
directly over the axle, and geared to it by bevel-w^heels.
118 MOVING FORCES USED IN THE ARTS.
When the fly-wheel moves too fast, the balls of the gov-
ernor recede from their centre, and, by acting on a lever,
[rs,'] cause it to turn upon its fulcrum, [i,] and partially to
close the steam-pipe, by a throttle-valve, at K. When
the velocity abates, the balls subside, and the valve opens,
so as to admit more steam.
L, is the air-pump, the use of which is, to discharge
the air and water, which collect in the condenser, M.
M, is the condenser, which is an empty, cylindrical
vessel, immersed in a cistern of cold water, SS, and
communicating with the cylinder by the pipe, O. It has
a valve, or cock, communicating with the cistern, and
moved by the rod, [gg-,'] through which a jet of cold
water enters it, for the purpose of condensing the steam.
N, is a small cistern, filled with water. Into this cis-
tern enters a pipe, from the condenser M, the top of
vvdiich pipe is covered by a valve, which is called the
bloio-valve^ or, sometimes, the snifting-valve. Through
this valve, the air, contained in the cylinder, D, and
passages from it, is discharged, on the engine being first
set in motion.
O, is the eduction-pipe, which conducts the steam from
the valve, I, to the condenser, M.
P, is the pump, which supplies w:ith water the cistern, or
cold well, SS, in which the condenser and discharging
pump stand.
QQ, are iron columns, which support the beam. Of
these, the engine has four, although only two are shown
They stand upon one entire plate, seen edgewise, on
which the principal parts of the engine are fixed.
PtR, is the recess below the floor, for containing the
cistern of the discharging pump, condenser, &c.
The condenser, M, and the air pump, L, communicate
by means of a horizontal pipe, containing a valve, [m,]
opening towards the pump ; the piston [n,] of this pump,
also contains two valves, and the cistern, T, at the top
of the pump-cylinder, contains other two valves, which,
like those of the piston, [n,] open upwards. When the
piston, E, of the cylinder, is depressed, the piston [n,] of
the discharging pump, it will be obvious to inspection,
EXPANSION ENGINES. 119
will be depressed, likewise, and its valves open, while the
valve, [?7i,] closes ; hence, the water of the condensed
steam, as well as the injection water, and any vapor of
air, which may be present, having passed through the
valve, [m,] passes through the piston, [n ;] and, when that
piston is drawn up, its valves close, and prevent their
return, as in common pump-w'ork. The water and air,
that have thus got above the piston, as the latter rises,
open the valves at the bottom of the cistern, T, in which
the water remains till it is full ; but the air passes into the
atmosphere. As the water in the cistern, T, is in a hot
state, a part of it, for the purpose of economizing fuel, is
pumped up, and returned to the boiler, the pump-rod
being attached to the great beam.
The steam, constantly rushing into the condenser, M,
has a perpetual tendency to heat that vessel, as well as
the water of the cistern, SS, in which it stands ; the
whole of the steam, if this were unchecked, would not be
condensed, or the condensation would not be sufficiently
rapid, because the injection water itself flows out of this
cistern. A part of the water is, therefore, allowed to
flow from this cistern by a waste pipe, and an equal quan-
tity of cold water is constantly supphed by the pump, P.
The cylinder, D, is, in many cases, surrounded by a
case, to keep it from being cooled too much, by contact
with the external atmosphere.
Expansion Engines. — The steam, which impels an
engine is always diminished in volume, by the resistance
which it has to overcome, and tends, naturally, to occupy
a larger space, than that to which it is confined, while the
engine is at work. If it be dismissed into the air, or into
the condenser, while under its greatest working pressure,
it will not have produced all the useful effect, which it is
capable of afibrding. If, on the contrary, it be separa-
ted, and placed under circumstances, where it can still
expand further, before it is dismissed, this expansion will
be so much additional gain to the power of the engine.
Its general principles have already been discussed.
The expansive power of steam may be converted to
use, in various ways, and most of the common forms of
120 movi:jg forces used in the arts.
the steam-engine rnav be made to act expansively, by a
proper arrangement of their valves. In Watt's engine,
this effect is produced, by cutting off the steam from the
cylinder, before the stroke of the piston is completed,
leaving it to the steam, already in the cylinder, to assist,
by its expansion, in completmg the stroke. The steam
in the boiler, being thus intercepted, acts only at intervals
Nevertheless, its whole disposable force is accumulated in
the fly-wheel, while, at the same time, the force, arising
from the expansion of steam in the cylinder, serves to in-
crease the total amount. A great augmentation is thus
produced, in the useful effect of an engine, with the same
amount of fuel and water.
Mr. Hornblower, who was one of the first inventors
of the apphcation of expansive steam, employed two
cylinders, having their pistons connected to the same
beam. In the smaller of these, the steam was used, at
full pressure, after which it was discharged into the lar-
ger cylinder, where it again acted, by its expansive force.
This method affords a more equable mode of applying
the expansive force of steam, than that used by Mr
Watt ; but the engine is more complex and expensive.
Mr. Woolf afterwards adopted the plan of two cyhn
ders, with the addition of using his steam at a high pres-
sure, together with a condenser. He appears to have
exaggerated the expansive force of steam, at high tem-
peratures, as various other projectors have done. His
engines, however, continue to be used and approved, in
different parts of England and Wales, and their perfor-
mance is stated to exceed that of any other kinds.
Condenser. — It has already been stated, that, in the
original atmospheric engine of Newcomen, the steam was
condensed by a jet of cold water, thrown into the cylin-
der. A great improvement, in the economy of heat, was
made by Mr. Watt, who introduced the separate con-
denser. But, even with uis improvement, there is some
loss of power, in consequence of the necessity of con-
tinually pumping out the water, which has been injected,
to condense the steam. Sea-water, also, gives trouble,
by the deposit of salt in the boiler. To obviate these
VALVES. 121
difficulties, condensers have been made, of a multitude of
small tubes, communicating with the eduction-pipe, and
kept immersed in cold water. In this way, sufficient
heat escapes, through the surface of the tubes, to condense
the steam, without the necessity of injection ; and the
water is kept fresh. Some of the Atlantic steam-boats
have had condensers of this kind. A difficulty, however,
is found, in the expansion and contraction of the tubes,
which makes it necessary to receive the ends of all of
them in stuffing boxes, which admit motion, but are li-
able to get out of order. In a large engine, now work-
ing at the Iron-works, in Boston, Mr. Treadwell has in-
troduced a condenser, the tubes of which are bows, having
both ends soldered to the same surface, and, therefore,
not liable to be displaced, by expansion, or contraction.
Valves. — The valves of steam-engines are shutters,
which guard the avenues to the boiler and condenser, so
that, by opening and shutting them, at the required time,
the steam may be made to enter, or escape, at either end
of the cylinder. Valves, of a great variety of forms,
have been used in different engines, some of which have
a reciprocating, others, a rotary, motion. The puppet
valve is a cone, or frustum of a cone, which is fitted, like
a cover, to a conical aperture, which it opens, by rising,
and closes, by faUing. Sliding valves are those which do
not rise, but slide on and off of their apertures. Som.e
of these have a cavity, on their under side, capable of
connecting two apertures together, or of forming a com-
munication between them, while a third aperture is shi;t.
Rotary valves are usually constructed like common stop-
cocks, excepting that they comme'nd more passages than
one, at the same time. If the handle be placed in one
position, it opens one pfssage, while it closes another ; if
in a different position, it closes the first, and opens the
second. A throttle valve is a partition, turning on an
axis, and placed across the interior of a pipe. If turned
edgewise, it permits the steam to pass ; but, if turned
transversely, it obstructs its passage. This valve is com-
monly placed in the main steam-pipe, and connected with
II. 11 XII.
122 MOVIXG FORCES USED IN THE ARTS.
the governor, to regulate the quantity of steam supplied
by the boiler.
On account of the heat which is kept up in steam-en-
gines, the principal valves require to be of metal, and are
fitted, by grinding, closely to their seats. Valves made
with leather, like the common clack valve of a pump,
can only be used about the condenser, where the temper-
ature is low.
Pistons. — As the piston is hable to continual wear, by
"ts friction against the inside of the cylinder, it can only
be kept sufficiently tight, by rendering its circumference
elastic. This is commonly done, by winding it with
hemp, loosely twisted. The hemp packing, however,
gets out of order, in time, and requires to be renewed.
To remedy this evil, various plans have been introduced,
for making elastic pistons of metal only. The pistons
invented by Cartwright and Barton, consist of several
parallel circular plates, in close contact with each other.
These are cut into segments, and the segments pressed
outward, by steel springs, care being taken, that the fis-
sures, in the different plates, do not coincide. In the pis-
ton of Jessop, a spiral coil of steel is wound on the cir-
cumference of the piston, which expands, by its own elas-
ticity, so as to keep in tight contact with the cylinder.
To increase the tightness and elasticity of the piston, a
hempen packing is placed within the coil.
Parallel Motion. — A simple form of a parallel mo-
tion, for converting the rectilinear motion of the piston
into the curvilinear one of the beam, has already been
described, on page 66. Another form is shown in Plate
III., w^here the rod, [«^,] turns upon the joint, [«,] as a
fixed centre, while the rod, [c6,] turns upon [6,] as a cen-
tre. While the point, [c,] would describe a curve about
ts centre, [6,] the point, [6,] describes an opposite curve
about its centre, [a.] These two curvatures compensate
each other, so that the point, [c,] to which the piston is
attached, describes nearly a straight line.
The parallel motion was introduced by Mr. Watt, and
is, probably, attended with less friction than any other ar-
rangement, for effecting the same object. It requires
LOCOMOTIVE ENGINE. 123
however, to be constracted with great accuracy. Va-
rious other methods have been apphed, to convert the
rectilinear into a curvihnear movement. Sometimes, the
piston is confined to its path by guides, or friction wheels,
and connected to the beam by a double joint. In New-
comen's engine, where the principal force was in the
downward stroke, the piston was connected, by a chain,
to an arched head, at the end of the beam. In Cart-
wright's engine, the piston was attached to two opposite
cranks, which were geared together, as shown on page
66. In some of Murray's engines, the epicycloidal
movement was employed. [See page 69.]* In Maud-
slay's engine, and some others, instead of a beam, a
cross-head is used, the whole of which moves up and
down, in guides, instead of turning on a centre. In the
vibrating engines of Lester, and others, the cylinder is
hung upon a movable axis ; and, in Morey's engine, the
cylinder revolves, hke a fly-wheel, the piston being made
to act on a fixed crank.
Locomotive Engine. — This engine is used, as a propel-
ling powder, on rail-ways, and has been introduced in a
previous chapter. The accompanying figure shows the
internal construction of one of these machines.
F, represents the fire-box, or place where the fire is
kept ; D, the door, through which the fuel is introduced ;
G, one of the bars of the grate, at the bottom ; the spa-
ces, marked B, are the interior of the boiler, in which the
water stands, at the height indicated by the dotted line
The boiler is closed on all sides ; all its openings being
guarded by valves. The tubes, marked [ee,] conduct
the smoke and flame of the fuel, through the boiler, to the
chimney, CC, serving, at the same time, to communi-
cate the heat to the remotest part of the boiler. By this
arrangement, none of the heat is lost ; as these tubes are
all surrounded by the water. SSS, is the steam-pipe,
open at the top, BS, having a steam-tight cock, or reg-
ulator, V, which is opened and shut by the crank, H,
* For an account and figure of an engine, of this kind, see Farey on
the Steam Engine, p. 686, and Plate XVII.
124 MOVING FORCES USED IN THE ARTS.
extending outside of the boiler, and which is managed by
the engineer.
The operation of the machine is as follows : The steam
being generated in great abundance, in the boiler, and
being unable to escape out of it, acquires a considerable
degree of elastic force. If, at that moment, the cock, V,
is opened, by the handle, H, the steam, penetrating into
the tube, S, at the top, near X, and in the direction of
the arrows, passes through the tube, and the valve, V,
and enters the valve-box, [i.] There, a sliding valve,
loo,^ which moves at the same time with the machine,
opens for the steam a communication, successively, with
each end of the cylinder. Thus, in the figure, the en-
trance, on the left hand of the sliding valve, is represented
as being open, and the steam follows, in the direction of
the dotted line, into the cylinder, where its expansive
force will move the piston, P, in the direction of the ar-
row. The steam, or air, on the other side of the piston,
passes out, in the direction of the dotted line, to [it,] which
communicates with the tube, [tt^] from which it passes
into the chimney, C, and thence into the open air. The
sliding valve, [oo,'] now moves, and leaves the right-hand
aperture open, while it closes the one on the left. The
steam then draws the piston back; and that portion of
steam, on the left of the piston, having performed its of-
fice, passes out of the aperture, [it,] an opening to which
is made, by the new position of the sliding valve. Thus,
the sliding valve, opening a communication, alternately,
with each side of the piston, the steam is admitted on
both sides of the piston, and, having performed its office,
it passes through the aperture, [it,] to the tube, [tt^] and
the chimney, C, and from thence into the open air.
Motion being thus given to the piston, it is communi-
cated, by means of the rod, R, and the beam, G, to the
crank, K ; which, being connected u-ith the axle of the
wheel, causes it to turn, and thus moves the machine.
Power of the Steam Engine. — Dr. Lardner has given
the following statements, relating to the power of the
steam-engine.
[n a report, published m 1835, it was announced, that
POWER OF THE STEAM-ENGINE. 125
a steam-engine, erected at a copper-mine, near St. Aus
lie, in Cornwall, bad raised, by its average work, ninety
five millions of pounds, one foot bigb, witb a busbel ol
coals. Tbis enormous mecbanical effect baving given
rise to some doubts, as to tbe correctness of tbe experi-
ments, on wbicb tbe report was founded, it was agreed,
tbat anotber trial sbould be made, in tbe presence of a
number of competent, and disinterested, witnesses. Tbis
trial, accordingly, took place, and was witnessed by a
Dumber of the most experienced mining engineers, and
agents. Tbe result was, tbat, for every busbel of coals,
consumed under tbe boiler, tbe engine raised one hun-
dred and tw^enty-five and a balf milbons of pounds weight,
one foot bigb.
It may not be uninteresting to illustrate tbe amount of
mecbanical virtue, which is thus proved to reside in coals,
in a more familiar manner.
Since a bushel of coal w^eighs eighty-four pounds, and
can lift fifty-six thousand and twenty-seven tons, a foot
high, it follows, that a pound of coal would raise six hun-
dred and sixty-seven tons, the same height ; and, tbat an
ounce of coal would raise forty-two tons, one foot high,
or it would raise eighteen pounds, a mile high.
Since a force of eighteen pounds is capable of drawing
two tons, upon a rail- way, it follows, that an ounce of
coal possesses mecbanical virtue sufiicient to draw^ two
tons, a mile, or one ton, two miles, upon a level rail-way.
The circumference of tbe earth measures twenty-five
thousand miles. If it w^ere begirt by an iron rail-way, a
load of one ton would be drawn round it, in six weeks, by
the amount of mecbanical power which resides in the
third part of a ton of coals.
The great pyramid of Egypt stands upon a base, meas-
uring seven hundred feet, each way, and is five hundred
feet bigb ; its weight being 12,760,000,000 pounds. To
construct it, cost tbe labor of one hundred thousand men,
for tw^enty years. Its materials w^ould be raised from the
ground, to their present position, by the combustion of
four hundred and seventy-nine tons of coals.
The weight of metal, in tbe Menai bridge, is four mil
i26 MOVING FORCES USED IN THE ARTS.
lion pounds, and its height, above tlie level of the water,
is one hundred and twenty feet. Its mass might be lifted
from the level of the water, to its present position, by the
combustion of four bushels of coals.
Projected Improvements. — Besides the improvements
which have been actually efiected, in the construction
and application of the steam-engine, a variety of projects,
for increasing the power and usefulness of this agent,
have, from time to time, occupied the attention of ingen-
ious men. Of the improvements which have been at-
tempted, some are opposed by obstacles, which have not
yet been satisfactorily surmounted, and others, by difficul-
ties, in themselves, insurmountable. The following have
been among the most prominent subjects of speculation.
1. Rotative Engines. — These are engines, in which
the steam is so applied, as to produce a direct rotary mo-
tion, without the intervention of a rectilinear movement.
Engines, on this principle, have been constructed in many
different ways. An idea of one of the most obvious
forms, may be obtained from the eccentric pumps, de
scribed in the following chapter, which have been con
verted into steam-engines, by reversing the motions, and
changing the resistance for the power. Some rotative
engines have been constructed on the principle of Bar-
ker's mill ; others have been made, by immersing an
overshot-wheel in a cistern of heated fluid, either water,
oil, or melted metal, and delivering the steam under the
ascending or inverted buckets ; so that, when these were
filled with steam, the full buckets, on the opposite side,
might preponderate, and cause the wheel to revolve.
But, in general, the rotary engines hitherto constructed,
have either been feeble in power, or encumbered with
excessive friction, on account of the extensive packing,
which is necessary, to keep them tight ; so that none of
them have found their way into use. It is probable, that
no method of constructing a variable cavity, for steam,
which is, in other respects, suitable, affords so advantage-
ous a mode of applying the power, as the cylinder and
piston, producing rectilinear motion.
Use of Steam at high Temperatures. — Innon-conden-
USE OF VAPORS OF LOW TEMPERATURE. 127
sing, or high-pressure engines, the power, which is conver-
tible to use, consists of the surplus which remains, after
overcoming the pressure of the atmosphere. Of course,
the higher is the temperature at which the steam is worked,
the greater is the total gain, supposing the absorption
of heat, and the production of power, to continue to take
place, in equal proportions. This consideration, with other
expected advantages, has given rise to many attempts to
improve the steam-engine, by devising modes of applying
steam, at much higher temperatures than those, which it
has been ordinarily found practicable to employ. At-
tempts of this kind have, also, frequently been founded
upon an undue estimate of the elastic force of steam, at
high temperatures, and of the absorption of heat, during
its production. In practice, it is found difficult to obtain
a material, capable of confining water and steam, in safety,
w^hen raised to such a temperature, as to produce a pres-
sure often, or more, atmospheres ; since, independently of
the strain upon the joinings, the cohesive strength of
metals is diminished, and their oxidation promoted, by
exposure to great heat.
Use of Vapors of low Temperature. — Certain Hquids,
such as alcohol, ether, sulphuret of carbon, and a hquid,
obtained by condensing oil-gas, have been proposed, as
substitutes for water, in producing steam, on account of
the low temperature, at which they are converted into
vapor. Thus, alcohol boils at about one hundred and
seventy-three degrees of Fahrenheit ; sulphuric ether, at
ninety-eight degrees ; muriatic ether, at fifty-one degrees ;*
sulphuret of carbon, at one hundred and sixteen degrees ;
and oil-gas liquid, at one hundred and eighty-six ; all of
which are lower than the boiling point of water. Some of
ihese, when raised to the boihng point of w^ater, have a
much greater elastic force than that fluid. Thus, the sul
phuret of carbon, at two hundred and twelve degrees, has
an elastic force equal to about four atmospheres,! and sul-
phuric ether, of nearly six atmospheres. But these advan •
* Ure's Dictionary.
t See Tredgold's Tables, Steam Engine, p. 78—81.
i^ MOVING FORCES USED IN THE ARTS.
tages are nearly counterbalanced, by the small spaces
through which these vapors act, their volume, at their
boiling point, being only from about an eighth to a third
part of that of steam, at the boiling point of vvater. To
this disadvantage may be added the expensive character
of these substances, and the difficulty of condensing them,
without loss, in any working engine. Some of them, hke-
wise, as the ethers, act, chemically, upon metals, and
could not, on this account, be employed in engines made
of the common materials.
Gas Engines. — It has been attempted to obtain power
for propelling machinery, from the combustion, or explo-
sion, of inflammable elastic fluids, such as coal-gas, and
the vapor of combustible liquids, mixed with atmospheric
air. In combustions of this kind, rarefaction, and sub-
sequent condensation, take place, which, if conducted
within suitable cavities, may be made to aflbrd a moving
power, applicable to machinery. The principal engines,
which have been constructed, for using this power, are
those of Messrs. Morey, in this country, and iirown, in
England. If a power of this kind could be made, to af-
ford an adequate propelling force for locomotive engines,
upon public roads, it would possess an advantage, in the
lightness of the machinery, compared with the weiglit of
steam-engines, with their water and fuel. But it remains
for experience to determine, whether the space, through
which the force will act, taken in connexion with the cost
of the materials, can render this an economical source of
power.
In addition to the foregoing method of procuring power,
by the combustion of gases, Sir H. Davy has proposed
the employment of certain fluids, which are volatile at
common temperatures, but which have been condensed
iuto liquids, under great pressure, such as carbonic acid,
ammonia, &c. His views are founded upon the immense
' difference which exists, between the increase of elastic
force in gases, under high, and low, temperatures, by simi-
lar increments of temperature. But doubts have been
raised upon this subject, with regard to the space, through
which the force of these gases will act, and, also^ in regard
STEAM-CARRIAGES. STEAM-GUN. 129
to the quantity of heat, requisite to produce tne change
of temperature required.*
Steam Carriages. — It has long been a favorite object
with projectors, to construct a form of the steam-engine,
in connexion with a carriage, which should be capable of
propelling itself upon the public roads. Locomotive en-
gines are capable of moving themselves upon rail-roads,
and of drawing with them additional loaded carriages ; be-
cause, in this case, the motion is uniform, and very little
of the power is expended, in surmounting obstacles, or
changing the form of the road. But, upon a pubHc high-
way, it requires, by a common estimate, about eight times
as much power to propel a carriage, as it does upon a
rail-road. Of course, the weight and inertia of an engine,
capable of producing this power, must increase somewhat
in the same proportion, and a great part of the power will
become necessary, to transport the machine itself. The
inertia, also, will be continually brought into unfavorable
action, by the jolts and concussions, inseparable from high-
way travelling, and thus endanger the destruction of a ma-
chine, requiring such nice adaptation of parts, as the steam-
engine. It appears, that steam-carriages have been made
to run upon good roads, during short experiments, while
the engine was new. But we have no account, as yet,
of any one having long performed this kind of service.
Steam Gun. — Mr. J. Perkins, f whose experiments on
the steam-engine are well known, has attempted the em-
ployment of the expansive force of steam, as a substitute
for gunpowder, in throwing projectiles. The steam-gun,
invented by him, is somewhat similar, in its construction,
to the air-gun ; but the power is derived from a magazine
of water, heated to a very high temperature ; so that, when
portions of it are discharged from the vessel containing
it, they produce steam enough to project a cannon ball
with great force. The balls are admitted into the gun,
in succession, from a hopper, and can be discnarged, at
* Philosophical Transactions, 1826, Tredgold, on the S earn Engine,
p 84.
t The public are indebted to Mr. Perkins, for the art of steel eugrav-
ing, the nail machine, and many other useful inventions.
130 MOVING FORCES USED IN THE ARTS.
the rate of twenty-four in a minute. It appears, from
some experiments made with these guns, in France, that
the projectile force of steam is greatly inferior to that of
gunpowder ; a consequence, no doubt, of the vast differ-
ence, which is known to exist, in the initial force of the
two agents ; nevertheless, the rapidity, with which the dis-
charges may be made, seems capable of advantageous
employment, in some situations.
GUNPOWDER.
Manufacture. — Gunpowder is a solid, explosive, mix-
ture, composed of nitre, sulphur, and charcoal, reduced
to powder, and mixed intimately with each other. The
proportion of the ingredients varies, very considerably ;
but good gunpowder may be composed of the following
proportions ; seventy-six parts of nitre, fifteen of char-
coal, and nine of sulphur, equal to one hundred. These
ingredients are first reduced to a fine powder, separate-
ly, then mixed, intimately, and formed into a thick paste.
This is done, by pounding them, for a long time, in wood-
en mortars, at the same time moistening them with water,
to prevent the danger of explosion. The more intimate
is the mixture, the better is the powder ; for, since nitre
does not detonate, except when in contact with inflamma
ble matter, the whole detonation will be more speedy, the
more numerous the surfaces in contact. After the paste
has dried a little, it is placed upon a kind of sieve, full of
small holes, through which it is forced. By that process,
it is divided into grains, the size of which depends upon
the size of the holes, through which they have passed.
The powder, when dry, is put into barrels, which are
made to turn round on their axis. By this motion, the
grains of gunpowder rub against each other, their asperi-
ties are worn off, and their surfaces are made smooth.
The powder is then said to be glazed. The granulation
and glazing of the powder causes it to explode more
quickly, perhaps, by facihtating the passage of the flame
among the particles.
Detonation. — When gunpowder comes in contact with
any ignited substance, it explodes, as is well known, with
FORCE. 131
^reat violence. This effect may take place, even in a
vacuum. A vast quantity of gas, or elastic fluid, is emit-
ted, the sudden production of which, at a high tempera-
ture, is the cause of the violent effects which this sub-
stance produces. The combustion is, evidently, owing to
the decomposition of the nitre, by the charcoal and sulphur.
The products are, carbonic oxide, carbonic acid, nitro-
gen, sulphurous acid, and, probably, sulphureted hydro-
gen. Mr. Cruikshanks has ascertained, that no percep-
tible quantity of water is formed. What remains, after
the combustion, is potash, combined with a small portion
of carbonic acid, sulphate of potash, a very small propor-
tion of sulphuret of potash, and unconsumed charcoal.
Force. — The elastic fluid which is generated, when
gunpowder is fired, being very dense, and much heated,
begins to expand, with a force, at least, one thousand times
greater than that of air, under the ordinary pressure of
the atmosphere. And, allowing the pressure of the at-
mosphere to be fourteen and three fourths pounds, upon
every square inch, the initial force, or pressure, of fired
gunpowder, will be equal to, at least, fourteen thousand
seven hundred and fifty pounds, upon every square inch
of the surface which confines it. But this estimate, which
is that of Mr. Robins, is one of the smallest which has
been made. According to Bernoulli, the initial elasticity,
with which a cannon ball is impelled, is, at least, equal to
ten thousand times the pressure of the atmosphere ; and,
from Count Rumford's experiments, it appears more than
three times gisater than this.
Gunpowder, on account of its expensiveness, and the
suddenness and violence of its action, is not employed as
a regular moving force, for machinery. It is chiefly ap-
plied to the throwing of shot, and other projectiles, and
the blasting of rocks.
When a ball is thrown from a gun, the greatest force is
applied to it, by each particle, at the moment of its explo-
sion. But, since the ball cannot, at once, acquire the
same velocity, with which the elastic fluid, if at liberty,
would expand, it continues to be acted upon by the fluid,
and its motion is accelerated, in common cases, until it
132 MOVING FORCES USED IN THE ARTS.
has escaped from the mouth of the piece. The acceler
ating force, however, is not uniform ; and, hence, the fol-
lowing circumstances deserve attention. 1. The elasti-
city is, inversely, as the space which the fluid occupies ;
and, therefore, as it forces the ball out of the gun, it con-
tinually diminishes. 2. The elasticity would diminish, in
this ratio, even if the temperature remained the same ;
but it must diminish, in a much greater ratio, because a re-
duction of temperature takes place, both from the disper-
sion of the heat, and the absorption of it, by the fluid it-
self, during its rarefaction. 3. The fluid propels the ball,
by following it, and acts with a force that is, other things
being equal, proportionate to the excess of its velocity,
above the velocity of the ball. The greater the velocity
that the ball has acquired, the less, therefore, is its mo-
mentary acceleration. 4. From this change of relative
velocity, there must be a period, when the velocity of the
ball wull exceed that of the elastic fluid ; and, therefore,
the proper length for a gun must be that, in which the ball
would leave the mouth, at the time wdien the velocities
are equal ; and all additional length of the piece, beyond
this, can only serve to retard the ball, both by friction,
and atmospheric pressure.
The force of fired gunpowder is found to be very near-
ly proportionate to the quantity employed ; so that, if we
neglect to consider the resistance of the atmosphere, then
the height to which the ball will rise, and its greatest hor-
izontal range, must be, directly, as the quantity of powder,
and, inversely, as the weight of the ball. Count Rum-
ford, however, found, that the same quantity of powder
exerted somewhat more force upon a large ball, than on
a smaller one.
Properties of a Gun. — The essential properties of a
gun are, to confine the elastic fluid, as completely as pos-
sible, and to direct the course of the ball to a rectilinear
path ; and hence arises the necessity of an accurate bore.
The icindage^ or space, produced by the difference of
diameter between the ball and the bore, greatly diminishes
the effect of the powder, by allowing a part of the elastic
fluid to escape, before the ball. The advantage of a rifle
PROPERTIES OF A GUNc 133
barrel is chiefly derived from the more accurate contaci
of the ball with its cavity. When the tore is twisted, it is
also supposed to produce a rotation of the ball round an
axis, in the direction of its motion, which renders it less
hable to deviate from its path, on account of '"regularities
in the resistance of the air. The usual charge of powder
is one fifth, or one sixth, of the weight of the ball ; and,
for battering, one third. When a twenty-four pounder
is fired, with two thirds of its weight of powder, it may be
thrown about four miles ; the distance being reduced, by
the resistance of the air, to about one fifth of that, which
it would describe, if thrown in a vacuum.*
It is certain, that the grains of gunpowder do not in-
flame at once, but that the inflammation occupies time, in
being communicated from one particle to another ; so that
they act, successively, rather than simultaneously, in im-
pelling the ball. This circumstance contributes, greatly,
to the safety of fire-arms ; for, if the whole charge of
powder exploded at once, the piece would be in danger
of bursting, before the inertia of the ball would be over-
come. It is on account of the suddenness of their deto-
nation, that the various fulminating powders are inappli-
cable to use, in fire-arms. The bursting of a gun may be
occasioned, by the defective condition of the metal, the
disproportionate amount of the charge, the adhesion and
inertia of the shot, or the inertia of some other body, op-
posing the escape of the charge. It is from this last cir
cumstance, that a gun is hable to burst, if fired with its
muzzle under water.
To enable gunpowder to exert its full efi:ect, the pro-
portions of the cavity of the piece, to the charge, should
be such, as to allow all the grains to explode, before they
leave the cavity ; and, also, to permit the elastic fluid to
expend as much of its pressure, as is capable of acceler-
ating the ball. The superiority of a musket, over a pis-
tol, arises from its prolonging the action of the powder in
this way. But, for reasons already stated, there are hm-
its to the length of the barrel, which cannot be usefully
* Young's Natural Philosophy, vol. i p. 350.
II. 12 XII
134 MOVING FORCES USED IN THE ARTS.
exceeded ; and these have been nearly settled, by com-
mon practice.
Blasting. — The splitting of rocks, by gunpowder, is
performed by drilling holes, to a certain depth, and in-
serting a charge of powder, at the bottom. The hole is
then filled up, by ramming in fragments of stone, bricks,
or other hard substances, keeping in a steel wire, which is
afterwards withdrawn, to furnish a passage for the prim-
ing, by which fire is communicated to the charge. To
prevent the danger of a spark, copper wire is often used,
instead of steel. And, to prevent the small fragments
from flying about, it is found useful to cover the rocks
with brush-wood, or some other elastic substance.
Rocks may be blasted, at a considerable depth under
water, by means of the diving-bell, which enables work-
men to drill and charge them in safety. In the method
practised at How^th, in Ireland, after the charge is insert-
ed, a tin tube is carried up from the rock, to the surface
of the water. It is kept empty, and made water-tight,
by screwing the joints to each other, as the bell ascends.
The powder is ignited, by dropping pieces of red-hot iron,
through the tube, from a boat at the surface. When the
depth exceeds twelve feet, no danger or inconvenience is
experienced by the boats, beyond a violent, eruptive, ebul-
lition of the w^ater.
Magnetic Engines. — Since the discovery of electro-
magnetism, by aid of which, very powerful magnets have
been obtained, various persons have introduced machines,
which revolve, and act upon a small scale, by magnet-
ic power. But a radical difficulty has hitherto attended
them, that the magnetic force acts at distances, so ex-
tremely small, and diminishes, in such a rapid ratio, as
the distance increases, that these machines have not been
found convertible to any very important use.
Works of Reference. — Smeaton's Miscellaneous papers
4to. 1814 ; — Robison's Mechanical Philosophy, vols. ii. and iii. ; —
Gregory's Mechanics ; — Brewster's Ferguson's Mechanics ; —
Nicholson's Operative Mechanic, 8vo. ; — Farey's Treatise on the
Steam Engine, 4to 1827 ; this is the most extensive work, on its sub-
ject ; — Tredgold, on the Steam Engine, 4to. 1828 ; this is the most
philosophic work, on the subject ; — Stuart, on the Steam Engine,
ARTS OF CONVEYING WATER. 135
Svo. 1824 ; — ^Partixgdox, on the Steam Engine, 8vo. 1825 ; — .
R,EiVwicK, on the Steam Engine, Svo. New York, 1830 ; — Bossut,
Traite Theoretique et Experimental d' Hydrodynamique, 1771 ; —
Dr BuAT, Traite d' Hydraulique, &c. 1786, &c. ; — Playfair's
Outlines of Natural Philosophy, Svo. 1819 ; — Ure's Dictionary of
Chemistry ; — Works of Coulomb, Desaguliers, De La Hire,
DePARCIEUX, HuTTON, RoBIXS, RuilFORD, &c.
CHAPTER XVII.
ARTS OF CONVEYING WATER.
Of Conducting Water, Aqueducts, Water Pipes, Friction of Pipes,
Obstruction of Pipes, Syphon. Of Raising XFa/e/-, Scoop Wheel,
Persian Wheel, Noria, Rope Pump, Hydreole, Archimedes' Screw,
Spiral Pump, Centrifugal Pump, Common Pumps, Forcing Pump,
Plunger Pump, De La Hire's Pump, Hydrostatic Press, Lifting Pump,
Bag Pump, Double-acting Pump, Rolling Pump, Eccentric Pump,
Arrangement of Pipes, Chain Pump, Schemnitz Vessels or Hunga-
rian Machine, Hero's Fountain, Atmospheric Machines, Hydraulic
Ram. Of Projecting Water, Fountains, Fire Engines, Throwincr
Wheel.
The employment of water, as an agent for producing
motion, has already been considered. It remains to at-
tend to the various modes, by which this fluid may be
conveyed, from one place to another, either for use in the
arts, or for apphcation to the necessary purposes of life.
The principal circumstances which require attention, un-
der this head, are the following. 1. The conducting of
water, from one place to another, having the same, or a
lower, level. 2. The raising of water, to a higher level.
3 The projection of water, through the atmosphere.
OF CONDUCTING WATER.
Aqueducts. — When water flows in a current, or stream,
as in rivers or canals, it does so in obedience to gravita-
tion, and in consequence of the surface being lower at the
end towards which it is flowing, than in that from which
it proceeds. Its motions are governed by laws, some-
what different from those of sohd bodies, descending upon
136 ARTS OF COxWEYING WATER.
inclined planes, and this difference is owing to the want
of cohesion among the particles. Instead of moving si-
multaneously, the particles continually change their rela-
tive position ; so that, while one portion of the fluid may
be moving rapidly, another may be stationary, or even
moving, by an eddy, in a contrary direction. The motion,
however, will continue, both in open channels, and in
properly constructed pipes, until an equilibrium is pro-
duced, by the surface, at both ends of the channel,
arriving at the same level. Aqueducts are artificial chan-
nels, or conduits, for the conveyance of water, in a hori-
zontal, or descending, direction. The aqueducts, con-
structed by the ancient Romans, were among the most
costly monuments of their arts. Several of these were
from thirty to a hundred miles in length, and consisted of
vast covered canals, built of stone. They were carried
over valleys, and level tracts of country, upon arcades,
which were sometimes of stupendous height and solidity.
A similar method has been practised, in some modern
cities, of warm, or temperate, climates.
In colder latitudes, if the course of the aqueduct is
above the ground, the water is liable to be interrupted, by
freezing, in winter. It has, therefore, become common,
to resort to subterranean passages for water, which are
placed so deep, as to be below the reach of frost, and are,
also, favorably situated, both for convenience and econ-
omy. Culverts, and drains, which are intended merely
to remove and expend Vv'ater, are usually made of brick,
or stone ; but, for conveying water with the smallesl
expenditure by loss, icater-pipes are most frequently re-
sorted to.
Water Pipes. — The pipes, by which water is conveyed
beneath the ground, are, generally, of small, or moderate,
size, and are intended to be water-tight. In consequence
of a well-known law of fluids, a water-pipe may possess
any degree of flexure, and any number of curvatures, be-
low the level of the fountain-head ; yet, if it be not ob-
structed by air, or any other internal obstacle, it will rise,
at the discharging end, and may be delivered, at the height
of the original level. Pipes, for transmitting water, have
IRON PIPES. 137
been made from a great variety of materials.* It is desir-
able that they should possess strength, tightness, and du-
rability, and that the material, of which they are composed,
should not be caj-able of contaminating the water. Wood-
en pipes are, commonly, hollow logs, perforated, by bo'ring
through their axis, and connected together, by making the
end of one log conical, and inserting it into a conical cav-
ity in the next. When large trunks are required, they
are composed of thick staves and hoops, like a cask.
They should, where practicable, be imbedded in clay,
and buried at a greater depth, than the frost is ever know^n
to penetrate. Wooden pipes are in common use, in this
country, but are liable to decay, especially at the joints,
where their thickness is smallest. In salt marshes, they
are more durable, though still liable to decay, from the
attrition, and decomposing effect, of the water within
them.
Iron pipes are, at the present day, considered prefera-
ble to those of wood, being stronger, and, in most situa-
tions, more durable. They are made of cast-iron, with
a socket, or enlarged cavity, at one end, into which the
end of the next pipe is received. The joints, thus form-
ed, are rendered tight, either by fiUing the interstices with
lead, or by driving in a small quantity of hemp, and fill-
ing the remainder of the socket with iron cement, made
of sulphur, muriate of ammonia, and chippings of iron.
Copper pipes are extremely durable, and are made of
sheet copper, with the edge turned up, and soldered.
They require to be tinned, inside, on account of the poison-
ous character of some of the compounds, which are hable
to be formed in them. Lead pipes are much employed, for
small aqueducts, owing to the facility with which they can
be soldered, and bent in any direction. They are com-
monly cast in short pieces, and afterwards elongated, by
drawing them through holes, in the same manner as wire.
Leaden pipes, in general, are supposed not to contaminate
the water contained in them^ because the carbonate of
* It appears, that the use of water-pipes was not unknown to the
ancients. Some rules, respecting the use of leaden and earthen pipes
are given by Vitruvius de Architectura, Lib. viii.
13*
138 ARTS OF CONVEYING WATER.
lead, which is sometimes formed in them, is insoluble in
water. They are not safe, however, for pumps and pipes,
intended to convey acid liquors. Stone pipes preserve
the water, contained by them, in a very pure state. They
are, however, expensive, on account of the labor of work-
ing them, with the exception of soap-stone, which, being
easily shaped and bored, may be usefully appHed to the
purpose of conveying w^ater, in those places where it is
easily procured. Earthen pipes, made of common pottery
ware, and glazed on the inside, are sometimes used, but
are more liable to be broken, than most of the other kinds.
Friction of Pipes. — In a river, or open channel, it is
observable, that the water flows most rapidly, in the mid
die of the upper surface, while it is most retarded, at the
edges, and at the bottom. In like manner, in a cylin-
drical pipe, the fluid has the greatest velocity, at the cen-
tre, or axis, and the smallest velocity, at the surface, or
where it is in contact with the pipe. The force, by w^hich
this retardation is occasioned, is commonly called fric-
tion. It differs, in many respects, from the friction of
solids ; and more resistance is occasioned, by the internal
action of the fluid particles upon each other, than by the
contact of the solid surface, in which they are contained.
The investigation of the laws which govern the move-
ments of fluids is intricate, and the results of experiment
have not agreed with the previous conclusions of theory.
Various writers, on the science of hydraulics, have treated
this subject with an extensiveness of research, which can
only be understood from their own works. Among the
more simple, practical, facts, to which it is useful to at-
tend, the following may be briefly stated. 1. The veloci-
ty of water is greater in a large pipe, than in a small one,
having the same position ; and hence, a large pipe will
discharge more water, in a given time, than a number of
small ones, having, jointly, the same capacity. A pipe,
of two inches diameter, will give more water, than five
pipes, of one inch diameter ; it being ascertained, that the
squares of the discharges are, very nearly, as the fifth pow-
ers of the diameters.* 2. Irregularities and inequalities,
* Robison's Mechcinical Philosophy, vol. ii. p 578.
OBSTRUCTION OF PIPES. 139
in the iiiameter of the pipe, dmiinish the amount of water
which they transmit, by ahering the direction of the par-
ticles, and by changing their velocity, so as to renew the
resistance of inertia. 3. In like manner, all curves and
angles, which occur in the pipe, have a similar retard-
ing effect, by creating new motions, or counter currents.
4. The form of the end of the pipe, which communicates
with the fountain-head, or reservoir, greatly affects the
quantity of water received by it. If it be gradually en-
larged, like a trumpet mouth, a larger quantity of water
will be received, than by any of the modes which follow,
because the direction, given to the particles by this form,
is most favorable to their admvssion. If the entrance to
the pipe be abrupt, in consequence of the cavity being
wholly cylindrical, the particles will have a tendency to
cross each other, and less water will enter the pipe, in a
given time. And, if the end of the pipe projects into
the reservoir, a variety of opposing forces will be pro-
duced, among the particles moving toward the entrance ;
so that a smaller quantity will be received by the pipe,
than in either of the preceding cases.
The form of the discharging orifice, also, influences the
quantity of water delivered by a pipe, in a given time.
If the end of the pipe be enlarged, by adding to it a frus-
tum of a hollow cone, the amount of w^ater discharged, in
some cases, may be prodigiously increased.* This fact,
described by Venturi, appears to be the result of the
pressure of the atmosphere, aided by the inertia and co-
hesiveness of the water.
Obstruction of Pipes. — Water pipes are liable to be
obstructed, chiefly, by the following circumstances. 1.
By the freezing of the water, in winter, if the pipe has
not been laid sufiiciently deep. 2. By the deposition of
sand and mud, in the low^er parts of the pipe. To obvi-
ate this, the water should pass through a strainer, before
it enters the pipe. And, if plugs are placed at the lower
parts of the bendings, then, whenever these are opened,
the water rushes out with sufficient rapidity, and carries
* See Edinburgh Encyclopedia, Art. Hydrodynamics, pp. 494, 495
140 ARTS OF CONVEYING WATER.
the deposition with it. 3. By the penetratwn of rootj,
or the growth of aquatic vegetables, in the cavity of the
pipe This principally happens in wooden pipes, after
they begin to decay. 4. By the collection of air, in the
upper parts of the bendings. This is a serious evil, and
may take place in all pipes, which have an undulating
course, or more vertical curvatures than one. When air
is thus confined in the pipes, the water will not rise to the
same height, at the discharging end, as at the fountain
head. The air, being the lighter fluid, tends to occupy
the highest part of the bendings. Any pressure, applied
at the fountain-head, tends to push this air a little beyond
the highest part, so as to make it occupy a portion of the
descending side of the curve. Of course, the sum of the
weights, in the descending sides, will be less than the sum
of the weights, in the ascending sides, and the fluids will
not be in equilibrium, except when the water, at the foun-
tain-head, is higher than that at the discharging end. The
conditions, upon which this equilibrium is produced, are
the same as- those which sustain the fluid, at different lev-
els, in Hero's fountain, the spiral pump, and the hydro-
static lamp.
The prevention of this evil consists, in avoiding ver-
tical curves, and in laying the pipe, if possible, w ith an
uninterrupted slope, or, at least, with only one slope in
each direction. When this is done, the air will escape
at one, or both, ends of the pipe. But, w^hen vertical
curves are unavoidable, an open tube, the height of which
is equal to that of the fountain-head, should be attached
to the highest part of the curve. By this arrangement,
the air will readily escape. In like manner, if a tight air-
box be fastened upon the upper part of the curve, and
filled with water, the air will escape into this box, and
displace the water, without interrupting the current in the
pipe. The air-box may be made to regulate itself, and
to discharge the air, when it is full, by means of a valve
in the top, connected with a floating, hollow^, copper ball.
As the air increases, the copper ball will subside with the
water, till it opens the valve, for the air to escape. In
Fig. 160, AB, represents an undulating pipe, of which
141
A, is the fountain-head, and B, the discharging end.
The water and air will arrange themselves, as represented
by the darker and lighter parts of the tube, and, being
in equilibrium, no water will be discharged. If an up-
right tube, C, be attached to either of the upper flex-
ures, it will discharge the air from that flexure. Or, if
a tight box, or vessel, D, be substituted, with a copper
float and valve, it will have a similar eflect. Simple
punctures, made in the upper part of the pipe, also answer
a temporary purpose.
Syphon. — The syphon may be regarded as an instru-
ment for the lateral conveyance, rather than the rising, of
water ; since the fluid must always be delivered, at a low-
er level than that at which it is received. The syphon
is a bent tube, of which one extremity, or leg, is longer
than the other. If the shorter leg be inserted in a fluid,
and the air be exhausted from the longer leg, by suction,
or otherw^ise, till the syphon is full of water, then the col-
umn of fluid in the longer leg will preponderate, and the
current will take place. This will continue, either till the
water, in the feeding vessel, sinks below^ the end of the
syphon, or that in the receiving vessel rises to the same
height with the other. As the movement depends upon
the pressure of the atmosphere, water cannot be raised,
in a syphon, to a greater height than thirty-four feet.
For practical use, the longer leg of the syphon is often
closed with a stop-cock, and the air exhausted from it, by
a small pump, till the leg is full. The stop-cock is then
opened, and the fluid immediately flows through the sy-
phon.
1.4.2 ARTS OF CONVEYING WATER.
OF RAISING WATER.
The lateral conveyance of water is effected, in the
modes already described, by the aid of its own gravity.
The raising of water is effected, against gravity, by the
employment of some moving force. Hydraulic machines,
for raising water, may be impelled by a current, or fall,
of the water itself, or by any other moving agent. Among
a great variety of machines, which have been constructed
for this use, the following are some of the most noticeable.
(Scoop Wheel. — If a water-wheel is provided with a
hollow axle, and if, in the place of spokes, or radii, it is
furnished with crooked tubes, or cavities, of a suitable
curvature, it will raise water to the height of its own axis,
whenever it revolves in the direction of the mouths of
the tubes. Each spoke, or curved tube, as it dips its
extremity in the water, lifts a certain portion of the fluid :
and, as the revolution continues, this water will flow-
through the tube, approaching nearer to the axis, until it
is discharged into the central hollow. To prevent the
water from regurgitating, the inner ends of the tubes must
be guarded by valves, or else made to project, for a
short distance, into the central cavity, as seen at A, in
Fig. 161. In the latter case, it is necessary, that thev
Fig. 161.
should enter, at different distances from the end of the
axle. The axle may also be divided into as many lon-
gitudinal compartments, as there are tubes in the wheel.
PERSIAN WHEEL. NORIA. ROPE PUMP. 14^3
This was done in the ancient tympanum, a machine de-
scribed by Vitruvius, which was somewhat similar, in its
principle, to the scoop-wheel.
Persian Wheel. — The Persian wheel, in certam re-
spects, resembles the scoop-wheel, and is sometimes
combined with it, in the same machine. It differs from it,
hi its effect, by raising the water through the whole di-
ameter of the wheel. Its form is easily understood, by
supposing a number of buckets to be hung round the cir-
cumference of a water-wheel, upon pivots, at equal dis-
tances. As the wheel turns, the buckets are successively
immersed in the water, at the bottom, and filled. They
then pass upwards, till they arrive at the top of the wheel,
where they strike a fixed obstacle, and are overset, dis-
charging their water into a trough, placed at the top, to
receive it. This machine is saidto be-in common use,
in several of the Oriental countries.
J^oria. — The machine used in Spain, under the name
of noria, consists of revolving buckets, like the Persian
wheel. But, instead of a single wheel, two drums, or
trundles, are employed, and the buckets are attached to
ropes, or chains, passing round them. In Spain, earthen
pitchers are said to be used; but, in other countries,
wooden buckets are employed, like those of an over-
shot-wheel. A sufficient idea of the form of the noria
may be obtained, by inspecting the figure of the chain-
wheel, on page 89, and supposing the motion reversed.
Rope Pump. — Instead of a series of buckets, connec-
ted by ropes, or chains, a similar effect is, sometimes, pro-
duced by a simple rope, or a tundle of ropes, passing
over a wheel above, and a pulley below, moving with a
velocity of about eight or ten feet in a second, and draw-
ing up a certain quantity of water, by its friction. It is
probable, that the water commonly ascends, with about
half the velocity of the rope. While the water is, prin-
cipally, supported by the friction of the rope, its own co
hesion is sufficient to prevent it from wholly falling, oi
being scattered, by any accidental inequality of the mo
tion. The portion raised is collected in a trough, at
the top.
144 ARTS OF CONVEYING WATER.
Hydreole. — This name is given by M. Mannoury
Dectot, to an invention for raising water, by the admix-
ture of atmospheric air. If a column of water be inti-
mately mixed with air, in small bubbles, the air will or
cupy some time in ascending to the surface; and the
meanwhile, the collective specific gravity of the whole
colinnn will be much less, than if it consisted of water
alone. If a vertical tube be placed in a reservoir of wa-
ter, and if a quantity of air be injected into the bottom of
the tube, by a bellows, or forcing pump, the water in the
tube will immediately rise to a higher level, and remain,
until the air has escaped at the top. And, if the tube be
of proper height, the water will overflow, in the same
manner as it does during the ebullition of boihng liquids.
This appears, however, not to be a very economical mode
of applying force.
Jlrchimedes'' Screw. — This name is given to a machine,
formed by one or more pipes, wound spirally round a
cylinder, which revolves on an axis, in an oblique situa-
tion. It is used, in some places, under the name of wa-
ter-snail. Its mode of operation may be easily conceiv-
ed, by supposing a tube, formed into a hoop, to be rolled
up an inclined plane, in which case, the fluid would be
forced, by the elevation of the tube behind it, to run, as
it were, up hill. The screw is usually turned, by a water-
wheel. During each revolution, the lower end of each
spiral tube is immersed in the water, and dips up a cer-
tain quantity. This water, by its gravity, keeps to the
lower side of 'lie screw,, as seen in Fig. 162 ; but, at the
Fig. 162.
WATER-SCREW. SPIRAL PUMP. 145
same time, in consequence of the revolutions of the screw,
it passes continually upward, until it is delivered, at the
highest end.
This instrument is sometimes made, by fixing a spiral
partition round a cylinder, and covering it with an exter-
nal coating, either of wood, or of metal. It should be
so placed, with respect to the surface of the water, as to
fill, in each turn, one half of a convolution ; for, when
the orifice remains always immersed, its effect is much
diminished. It is generally inclined to the horizon, in an
angle of between forty-five and sixty degrees ; hence it
is obvious, that its utility is limited to those cases, in
which the water is only to be raised to a moderate height.
The spiral is seldom single, but usually consists of three
or four separate coils, forming a screw, which rises, more
rapidly, round the cylinder.
A icater-screw, which operates in a similar manner,
may be made, by a spiral partition, wound upon a central
axis, and revolving, by itself, within a smooth hollow
cylinder, to the cavity of which it is nearly fitted. In
this form, however, there is some loss, by the leakage
between the screw, and the cyHnder which contains it.
Spiral Pump. — This machine is formed, by a spiral
pipe, consisting of many convolutions, arranged either in
a single plane, as in Fig. 163, or in a cylindrical, or con-
Fi?. 163.
ical, surface, and revolving round a horizontal axis. The
pipe is connected, at one end, by a central water-tight
joint, to an ascending pipe, while the other end receives,
during each revolution, nearly equal quantities of air and
II. 13 XII.
146 ARTS OF CONVEYING WATER.
water. It was invented, about 1746, by Andrew Wirtz,
a pewterer, at Zurich ; whence it is often called the Zu-
rich machine. It is said to have been used, with great
success, at Florence, and in Russia. Dr. Young states,
that he has made use of it, for raising water, to a height
of forty feet. The end of the pipe is furnished with a
spoon^ containing as much water as will fill half of one of
its coils. The water enters the pipe, a httle before the
spoon has arrived at its highest situation, the other half
remaining full of air. The air communicates the pres-
sure of the column of water to the preceding portion ;
and, in this manner, the efiect of nearly all the water in
the wheel is united, and becomes capable of supporting
the column of w^ater, or of water mixed with air, in the
ascending pipe. The air, nearest the joint, is compressed
into a space, much smaller than that which it occupied at
its entrance ; so that, where the height is considerable, it
becomes advisable to admit a larger portion of air than
would, naturally, fill half the coil. This lessens the quan-
tity of water raised, but it lessens, also, the force requir-
ed to turn the machine. The joint should be conical, in
order that it may be tightened, when it becomes loose ;
and the pressure ought to be removed from it, as much
as possible. The loss of power, supposing the machine
well constructed, arises only from the friction of the wa-
ter on the pipes, and the friction of the wheel on its axis ;
and, where a large quantity of water is to be raised to a
moderate height, both of these resistances may be ren-
dered inconsiderable. But, when the height is very great,
the length of the spiral must be much increased, so that
the weight of the pipe becomes extremely cumbersome,
and causes a great friction on the axis, as well as a strain
on the machinery.
Centrifugal Pump. — The centrifugal force has some-
times been employed, in conjunction with the pressure
of the atmosphere, as an immediate agent, in raising wa-
ter, by means of a rotary pump. The machine, called
centrifugal-pump, consists of a vertical pipe, capable of
revolving round its axis, and connected, above, with a hor-
izontal pipe, which is open at one, or at both, ends ; the
COMMON PUMPS.
147
whole being furnished with proper valves, to prevent the
escape of the water, when the machine is at rest. As
soon" as the rotation becomes sufficiently rapid, the cen-
trifugal force of the water, in the horizontal pipe, causes
it to be discharged, at the ends, its place being supplied,
by means of the pressure of the atmosphere on the reser-
voir below, which forces the water to ascend, through
the vertical pipe. This machine may be so arranged,
that, according to theory, very Httle of the force applied
is lost ; but it has failed of producing, in practice, a very
advantageous effect. In Fig. 164, a centrifugal pump is
Fig. 164.
represented. The machine is first filled witn water,
through the funnel. A, while the valve, at D, prevents the
water from descending. The whole is then made to
turn rapidly, and the water is discharged, from the ends
of the horizontal part, into a circular trough, a section of
which is seen at B, and C.
Common Pumps. — A pump is a machine, so well
known, and so generally used, that the denomination has
sometimes been extended to hydraulic machines of all
kinds. The term, however, in its strictest sense, is to
be understood of those machines, in which the water is'
raised, by the motion of one sohd within another ; and this
motion is usually alternate, but sometimes continued, so
as to constitute a rotatior. In the pumps most com
148
ARTS OF CONVEYING WATER.
monly used, a cavity is enlarged and contracted, by turns,
the water being admitted into it through one valve, and
discharged through another.
The common household-pump has otherwise been call-
ed the sucking-pump, from the circumstance, that the
water is raised in it, by the pressure of the atmosphere.
In this country, pumps are made for common use, both
in wells, and in ships, by boring logs, so as to produce a
large hollow, and inserting two hollow wooden plugs, cal-
led boxeSj at different heights, both of which are furnish-
ed with valves, or clappers, opening upw^ards. The
lower box is made stationary, and serves merely to pre-
vent the water, which is raised, from running back. The
upper box is a hollow movable piston, attached, by its
rod, to the handle, or brake, of the pump. "When the
pump is full of water, every stroke of the handle raises
this box, together with the column of water above it.
When the handle is hfted, the box is pushed further down
hito the water, while its valve opens, to allow the w^ater
to pass through. In Fig. 165, this pump is represented,
Fig. 165.
with the box just beginning to dtscend. The valve then
shuts, and the second stroke of the pump raises another
column of water to the spout. As the action of this
pump depends upon the pressure of the atmosphere, wa-
FORCING-PUMP. PLUNGER-PUMP.
149
ter cannot be raised by it, from a depth of more than thir-
ty-four feet below the upper valve ; and, in practice, a
much shorter limit is commonly assigned.
Forcing Pump. — The forcing-pump differs from the
common sucking-pump, just described, in having a sohd
piston, without a valve, and the spout, or discharging
orifice, placed below the piston. When the piston is
raised, the lower valve of the pump rises, and admits the
water from below, as in the common pump. But when
the piston is depressed, the water is thrown out, through
a spout in the side, which has a valve opening outward,
at [a,] in Fig. 166. In a forcing-pump, the whaler cannot
Fiff. 166.
be brought from a depth, of more than thirty-four feet be-
low the piston ; but it can afterwards be sent up, to any
height desired, in a pipe, [«t,] because the pressure, com-
municated by the downward stroke of the piston, is not
dependent on the pressure of the atmosphere, but upon
the direct force applied to the piston.
Plunger Pump. — A very effectual pump, for raising a
large quantity of water, to a small height, is shown in
Fig. 167, on the following page.
It is made, by fitting two upright beams, or plungers,
A and B, of equal thickness, throughout, into cavities,
13*
150
ARTS OF CONVEYING WATER.
Fig. 167.
nearly of the same size, allowing them only room to move
without friction, and connecting the plungers together, by
a horizontal beam, moving on a pivot. The water being
admitted, during the ascent of each plunger, by a large
valve, in the bottom of the cavity, at C and D, it is
forced, when the plunger descends, to escape through a
second valve, at E or F, in the side of the cavity, and to
ascend, by a wide pipe, to the top of the machine. The
plungers ought not to be, in any degree, tapered ; be-
cause, in this case, a great force would be unnecessarily
consumed, when they descend, in throwing out the water,
with great velocity, from the interstice formed by their
elevation. This pump may be worked by a laborer,
walking backwards and forwards, either on the beam, or
on a board, suspended below it. By means of an ap-
paratus of this kind, described by Professor Robison, an
active man, loaded with a weight of thirty pounds, has
been able to raise five hundred and eighty pounds of water,
every minute, to a height of eleven and a half feet, for
ten hours a day, without fatigue. This, says Dr. Young,
is the greatest effect produced by a laborer, that has ever
been correctly stated, by any author ; it is equivalent to
somewhat more than eleven pounds, raised through ten
feet, in a second, instead of ten pounds, which is a fair
estimate of the usual force of a man, without any deduc-
tion for friction.
OE LA hire's pump.
151
i>6 Z^ Htrtrx Pump. — A pump, partaking of the nature
til a forcing and a sucking pump, is sometimes called a
mixed pump. In De La Hire's pump, which is of this kind,
and shown in Fig. 168, the same piston is made to serve
Fig. 168.
a double purpose ; the rod woiking in a collar of leathers,
and the water being admitted and expelled, in a similar
manner, above and below the piston, by means of a double
apparatus of valves and pipes. When the piston is de-
pressed, the water enters the barrel at the valve. A, and
goes out at B. When the piston is elevated, it enters at
C, and escapes at D.
For forcing-pumps, of all kinds, the common piston,
with a collar of loose and elastic leather, is preferable to
those of a more complicated structure. The pressure of
the water, on the inside of the leather, makes it sufficiently-
tight, and the friction is inconsiderable. In some pumps,
the leather is omitted, for the sake of simpHcity, the loss
of water being compensated by the greater durability of
the pumps ; and this loss will be the smaller, in propor-
tion, as the motion of the piston is more rapid.
Hydrostatic Press. — This powerful machine is essen-
tially a forcing-pump, aided, in its action, by the well-known
properties of hydrostatic pressure. It appears to have
been invented by Pascal, previously to 1664, and recom-
mended by him, as a new mechanical power. It was,
however, practically, lost sight of, till it was re-invented by
152
ARTS OF CONVEYING WATER.
Mr. Bramah, more than a century afterwards. In tlin
press, the water is forced, by a small pump, into a strong
iron cylinder, in which it acts on a much larger piston ;
consequently, this piston is urged by a force, as much
greater than that which acts on the first pump-rod, as its
surface is greater than that of the small one. In Fig.
169, the water is forced, by the pump. A, through the
Fig. 169.
FrTnl rnpl.
pipe, B, into the cylinder, C, in which it acts, very pow-
erfully, upon the large piston, D, and raises the bottom of
the press, E. The upward force, by which the material,
above E, is compressed, exceeds the force, which is ap-
plied to the pump, as much as the surface of the piston,
D, exceeds that of the piston of the pump. In practice,
the cylinder, C, requires to be made much thicker than
here represented.-
Lifting Pump. — Where the height, through w^hich the
water is to be raised, is considerable, some inconvenience
might arise, from the length of the barrel, through which
the piston-rod of a sucking-pump would have to descend,
in order that the piston might remain within the hmits of
atmospheric pressure. This may be avoided, by placing
the movable valve, below the fixed valve, and introducing
the piston, at the bottom of the barrel. It is then w^orked,
by means of a frame, on the outside. Such a machine
is called a lifting-pump. In common with other forcing-
pumps, It has the disadvantage of thrusting the piston be-
fore the rod, and thus tending to bend the rod, and pro-
duce an unequal friction on the piston, while, in the suck-
BA.a-PUMP. DOUBLE-ACTING PUMP.
153
ing-pump, the principal force always tends to straighten
the rod.
Bag Pump. — A bag of leather has sometimes been
employed, for connecting the piston of a pump with the
barrel, and, in this manner, nearly all friction is avoided.
It is probable, however, that the want of durability would
be a great objection to such a machine. In Fig. 170, A,
represents a leathern bag, attached to a number of hoopb.
This bag is alternately extended and contracted, like a
bellows, by every stroke of the piston, and raises the wa-
ter, without friction against the pump.
Double-acting Pump. — The rod of a sucking-pump,
may also be made to work in a collar of leather, at the
top, as at A, in Fig. 171, and the water may be forced
Fisr. 171.
154 ARTS OF CONVEYING WATER.
through a valve, into an ascending pipe, B. By applying
an air-vessel to this, or to any other, forcing-pump, as is
done in fire-engines, its motion may be equalized, and its
performance improved ; for, if the orifice be large enough,
the water may be forced into the air-vessel, during the
stroke of the pump, with any velocity that may be re-
quired, and with little resistance, from friction ; whereas,
the loss of force, from the frequent accelerations and re-
tardations of the w^hole body of water, in a long pipe,
must always be considerable. The condensed air, re-
acting on the w^ater, expels it more gradually, and in a
continual stream, so that the air-vessel has an effect, anal-
ogous to that of a fly-wheel, in mechanics.
Fig. 172.
Rolling Pump. — A pump of this kind is formed, by a
bavrel, or hollow cylinder, shown in section, in Fig. 172,
naving two partitions. One of these, iVB, is fixed, and
the other, CD, is composed of two wings, or valves, ca-
pable of an alternate motion, about the axis of the cylin-
der. When the partition, CD, turns in one direction,
the water, in the cavity, C, is driven out at the orifice, [a,]
and will rise in a pipe, attached to that orifice. At the
eane time, the water, in the cavity, D, is forced out at
the orifice, [d]. While this is taking place, fresh por-
tions of water enter the remaining cavities, [at mand z].
When the partition, CD, has moved, as far as possible, it
then returns, in the opposite direction, and drives out the
water, through [y and a;,] and receives fresh water,
through [b and c]. The orifices, which receive the
water, have valves, opening inward, and those, which dis-
charge it, have valves, opening outward. The machine
ECCENTRIC-PUMP.
155
is worked by arms, attached to the axis of the cylinder,
which, for this purpose, projects through a collar, in the
ends of the vessel.
For the sake of simplicity, a sector of a cylinder is
sometimes used ; in which case, a single partition, or
valve, like a door on hinges, traverses the whole cavity,
and only half the number of orifices are necessary, to ad-
;*.it and discharge the water. Fire-engines, for project-
ing water, have been constructed, in byoih these methods,
by different inventors.
Fig. 173.
Eccentric Pump. — The eccentric pump, a section of
which is shown at Fig. 173, consists of a hollow cylinder,
[a(?,] in the interior of which, a solid cyhnder, [6,] of the
same length, but of about half the diameter, is made to
revolve, by its axle, passing through water-tight collars,
in the ends of the exterior cylinder. The internal cyl-
inder is so placed, that its surface comes in contact with
some part of the internal surface of the larger cylinder.
The surface of the small cylinder, is also furnished with
four large valves, or flaps, turning on hinges, and par-
takir.g of its own curvature ; so that, when they are, shut
down, they form no projections, but appear as parts of
the same cylinder. These valves are made to open, by
springs, or otherwise ; so that, when one of them is
brought, by the revolution of the internal cylinder, into
the narrowest part of the internal space, it is pressed
down, and shut ; but, as the inner cylinder moves on, tha
156 ARTS OF CONVEYING WATER.
valve, being gradually carried forward, will continue to
open, until it arrives at the widest part of the cavity. It
is then pressed down again, by a continuation of the rev-
olution. In this way, the water behind the valve is drawn
up, from the feeding-pipe, by the atmospheric pressure,
while that before the valve is forced upward, into the
delivering pipe. As each of the valves performs the
same operation, in its turn, this pump affords a constant
supply of water.
Rotative steam-engines have been constructed, by dif-
ferent projectors, on the principle of this pump, as well
as the following.
Fig. 174.
Another form of an eccentric pump, is seen in Fig.
174. The roller, or solid cylinder. A, revolving within
the reservoir, or hollow cylinder, BF, carries with it the
slider, DE, which is made to sweep the internal surface
of this cyhnder, by revolving, in the direction from C to
F, so that the water is drawn up, by the pipe, C, and dis-
charged, by the pipe, F.
An objection to all pumps of this sort is, that, if they
are made tight enough to hold water, they occasion a
great degree of friction, on account of the extensive con-
tact.of the moving surfaces. The continual change, also,
which takes place, both in the direction and velocity of
the water, is productive of great resistance from inertia.
The stream, at the delivering orifice, although never whol-
ly intermitted, is, by no means, uniform in its velocity.
Arrangement of Pipes. — The pipes, through which wa-
ter is raised, by pumps of any kind, ought to be as short,
and as straight, as possible. Thus, if we have to raise
CHAIN-PUMP, ETC. 157
water, to a height of twenty feet, and to carry it, to a hor-
izontal distance of one hundred, by means of a forcing-
pump, it will be more advantageous to raise it first, ver-
tically, into a cistern, twenty feet above the reservoir,
and then to let it run along horizontally, or find its level in
a bent pipe, than to connect the pump immediately with a
single pipe, carried to the place of its destination. And,
for the same reason, a sucking-pump should be placed as
nearly over the well as possible, in order to avoid a loss
of force, in working it. If very small pipes are used, they
will much increase the resistance, by the friction which
they occasion.
Chain Pump. — Water has sometimes been raised by
stuffed cushions, or by oval blocks of wood, connected
with an endless rope, or chain, and caused, by means of
two wheels, or drums, to rise, in succession, in the same
oarrel, carrying the water in a continual stream before
them. The magnitude, however, of the friction, appears
to be an objection to this method. From the resemblance
of the apparatus to a string of beads, it has been called a
bead-pump^ or paternoster-work. When flat boards are
united by chains, and employed, instead of these cushions,
the machine has been denominated a cellular pump ; and,
in this case, the barrel is usually square, and placed in
an inclined position. There is, however, a considerable
loss, from the facility with which the water runs back.
The chain-pump, used in the Navy, is a pump of this
kind, with an upright barrel, through which leathers, strung
on a chain, are drawn in constant succession. These
pumps are only employed, when a large quantity of water
is to be raised, and they must be w^orked with considera-
ble velocity, in order to produce any effect at all.
The Chinese work their cellular pumps, or bead-
pumps, by walking on bars, which project from the axis
of the wheel, or drum, that drives them ; and, whatever
objection may be made to the choice of the machine, the
mode of communicating motion to it, must be allowed to
be advantageous.
Schemnitz Vessels, or Hungarian Machine. — The
mediation of a portion of air is employed for raising wa-
ll. 14 XII.
158
ARTS OF CONVEYING WATER.
ter, not only in the spiral-pump, but also in the air-ves-
sels of Schemnitz, in the manner, shown in Fig. 175. A
column of water, descending through a pipe, C, into a
closed reservoir, B, containing air, obliges the air to act,
by means of a pipe, D, leading from the upper part of
the reservoir, or air-vessel, on the water in a second res-
ervoir, A, at any distance, either below or above it, and
forces this water to ascend, through a third pipe, E, to
any height less than that of the first column. The air-
vessel is then emptied, the second reservoir filled, and
the whole operation repeated. The air must, however,
acquire a density, equivalent to the pressure, before it can
begin to act ; so that, if the height of the columns were
thirty-four feet, it must be reduced to half its dimensions,
before any water would be raised ; and thus, half of the
force would be lost. But, where the height is small, the
force lost in this manner is not greater, than that which is
usually spent in overcoming friction, and other imperfec-
tions, of the machinery employed ; for the quantity of
water, actually raised by any machine, is not often greater
than half the power which is consumed. The force of
the tide, or of a river, rising and falling with the tide,
might easily be applied, by a machine of this kind, to the
purpose of raising water. Thus, if, at low tide, the ves-
HERO S FOUNTAIN, ETC
159
sel, A, was filled with air, then, at high tide, the w^ater,
dewing down the tube, E, would cause the water in the
vessel, B, to ascend in the pipe, C.
Heroes Fountain, — The fountain of Hero, precisely re-
sembles, in its operation, the hydrauHc vessels of Schem-
nitz, which were probably suggested to their inventor, by
(he construction of this fountain. It may be used, simply,
to raise water, or to project it upwards, in the form of a
pt, as in Fig. 176. The first reservoir, C, of the foun-
Fig. 176.
tain, is lowe^ 'han the orifice of the jet. A pipe descends
horn it, to the air-vessel, B, which is at some distance
below, and the pressure of the air is communicated, by
dn ascending tube, D, to a third cavity. A, containing the
water which supplies the jet. 1r this form of the ma
chine, the water will continue to spout from the pipe, E,
sintil all the water in the reservoir, C, has descended into
the vessel, B. The principle of Hero's fountain has
been applied, to raise oil in lampi- ; and one of its most
simple forms has already been desofibed, under the head
of Hydrostatic Lamp,, page 334, vol. I.
Atmospheric Machines. — The spontaneous vicissitudes
of the pressure of the air, occasioned by changes in the
weight and temperature of the atmosphere, have been ap-
plied, by means of a series of reservoirs, furnished wit^
proper valves, to the purpose of raising water, by degrees,
to a moderate height. But it seldom happens, that such
160
ARTS OF CONVEYING WATER.
changes are capable of producing an elevation m the
water of each reservoir, of more than a few inches, or,
at most, a foot or two, in a day ; and the whole quantity
raised must therefore be inconsiderable.
Hydraulic jRam.— The momentum of a stream of wa-
ter, flowing through a long pipe, has also been employed,
for raising a small quantity of water, to a considerable
height. The passage of the pipe, being stopped by a
valve which is raised by the stream, as soon as its mo-
tion becomes sufficiently rapid, the whole column of fluid
must necessarily concentrate its action, almost instantan-
eously, on the valve. In this manner, it loses the charac-
teristic property of hydraulic pressure, and acts, as if it
were a single solid ; so that, supposing the pipe to be per-
fectly elastic, and inextensible, the impulse may overcome
any pressure, however great, that might be opposed to it.
If the valve opens into a pipe, leading to an air-vessel, a
certain quantity of the water will be forced in, so as to
condense the air, more or less rapidly, to the degree that
may be required, for raising a portion of the water, con-
tained in it, to a given height. Mr. Whitehurst appears
to have been the first that employed this method. It was
afterwards improved by Mr. Boulton ; and the same ma-
chine has attracted much attention, in France, under the
denomination of the hydraulic ram of M. Montgolfier.
Fig. 177.
Fig. 177, represents this machine. When the water in
the pipe, AB, has acquired sufficient velocity, it raises
the valve, B, which immediately stops its further passage.
The momentum, which the water has acquired, will ther
OF PROJECTING WATER. FOUNTAINS. 161
force a portion of it, through the valve, C, into the air-
vessel, D. The condensed air, at D, causes the water to
rise into the pipe, E, as long as the effect of the horizon-
tal column continues. When the water becomes quies-
cent, the valve, B, will open again, by its own weight, and
the current will be renewed, until it acquires force enough
to shut the valve, and repeat the operation.
OF PROJECTING WATER.
If a degree of force, or pressure, be applied to water,
sufficient to raise it, through a tube, to a given height, the
same force would also cause it to spout through an ori-
fice, in a continued stream, or jet, to nearly the same
height, in common cases. The height, however, can
never be fully as great, for various reasons. One of
these is found, in the friction of the ajutage, or discharg-
ing orifice, which acts as a retarding force. Another
obstacle is, the resistance of the atmosphere, which in-
creases, in a rapid ratio, as the velocity of the water be-
comes greater, and which is also greatly augmented, as
the w^ater divides, and spreads out a greater surface to
the resistance of the air. A third obstacle consists, in
the resistance which the water offers to itself. The parts
first projected, being constantly retarded in their ascent,
by gravity, and atmospheric resistance, oppose the pro-
gress of the parts, which are last projected, and which
have the greatest velocity. And, as fluids move, in all
directions, this impulse, of different parts of the water,
against each other, tends to widen, and, consequently, to
shorten, the column. In a vertical jet, moreover, the
weight of the falling water opposes the ascending col-
umn ; and, hence, a fluid will spout higher, if the jet be
turned a little to one side, than if it be perpendicular.
Fountains. — Artificial fountains, which throw a per-
petual jet of water, usually act by the pressure of a res-
ervoir of water, situated at a greater height than that of
the jet produced. The w^ater is conveyed from the res
ervoir, to the place of the fountain, in pipes ; and, if the
orifice, from which it issues, be directed upward, it will
spout, to a height approaching tnat of the reservoir. Ii
14*
162 ARTS OF CONVEYING WATER.
will always, however, fall short of this height, for the
reasons already stated ; and the difference will be great-
er, in jets of great height, than it is in lower ones ; since
it is found, by experiment, that the differences between
the heights of the jets and of the reservoirs, are as the
squares of the heights of the jets themselves.* Foun-
tains are chiefly used, for purposes of ornament, and, when
of large size, require to be fed from the elevated parts
of rivers, or bodies of water, having a high level. At
Peterhoff, in Russia, there are two fountains, which spout
a column of water, nine inches in diameter, to the height
of sixty feet, and the fall of the returning water produces
a concussion, sufficient to shake the ground.
Fire Engines: — The engines used for extinguishing
fires, in buildings, are, in effect, a species of forcing
pumps, in which the water is subjected to pressure suffi-
ciently strong to raise it, by a jet, or otherwise, to- the re-
quired height. But, if the forcing pump were used alone,
the water would issue only in intermitting jets, in conse-
quence of the reciprocating motion of the pump, and
thus, a great part of it would become ineffectual. In or-
der to make the discharge uniform, and thus keep up a
continual stream, a strong vessel, filled with air, is at-
tached to the engine. Into this vessel, the water is forced,
by the pumps ; and, as the air cannot escape, it is con-
densed, in proportion as the water accumulates, until it
reacts upon the surface of the water, with great power.
If the air be condensed, into half the space which it orig-
inally occupied, it will act upon the water with a pressure,
equal to that of two atmospheres, and will be adequate
to raise water, through a tube, to the height of thirty-three
feet, or to project it, through the atmosphere, to nearly
the same height. When the air is condensed, to one
third of its former volume, in consequence of the air-
vessel being two thirds filled with water, its elasticity will
be three times greater than that of the atmosphere. It
will therefore raise water, in a tube, to the height of six-
ty-six feet, and would throw, it to nearly the same height,
* Ascertained by Mariotte. — Bossut, Tom. ii § 615.
THROWING-WHEEL. 163
were it not for the resistances, which have already been
explained.
The foregoing principle of the fire-engine has been
variously modified, by adapting different kinds of pumps
to the air-vessel, and by altering various details. In the
engines of Newsham, and others, two cylinders, con-
structed like forcing-pumps, are worked by the recipro-
cating motions of transverse levers, to which the handles
are attached. In this way, the water is forced into the
air-vessel, from which it afterwards spouts, through a
movable pipe. In some other engines, a single cylin-
der is used, the piston-rod passing through a tight collar,
as it does in Watt's steam-engine, thus alternately receiv-
ing and expelling the water, at each end of the cylinder.
In Rowntree's engine, and some others, a mechanism is
used, hke that of the rolHng-pump, a part of the inside of
a cylinder being traversed by a partition, like a door,
hinged upon the axis of the cylinder, which drives the
water, successively, from each side of the cyhnder, into
the air vessel.
A long flexible tube, made of leather, and known
among firemen by the name of hose, is of great use in
carrying the spouting orifice near to the flames, and thus
preventing the water from being scattered too soon. It
also serves an important purpose, in bringing water from
distant reservoirs, by suction, created in the pumps of
the engine.
Throioing Wheel. — A throwing-wheel, otherwise call-
ed a flash-wheel, or fen-wheel, is used for raising water,
both by lifting and projecting it. Its structure resembles
that of an undershot water-wheel, or, more properly, of
a breast-wheel. Its under surface is received in a trough,
or channel, which curves upward. When the wheel is
made to revolve, it drives the water before it, and throws
it out from the trough, at a considerable elevation. These
wheels are used, for draining ponds, marshes, &c., and
are turned by wind-mills, or any other power. If their
movement is slow, they simply lift the water, and cause
it to overflow, at the end of the trough. But, if they
164 COMBINING FLEXIBLE FIBRES.
revolve vv'th much velocity, they are capable of throw-
ing the water to a still higher level.
VV^ORKs OF Reference. — Robison's Mechanical Philosophy, ar-
ticles. Theory of Rivers, Water Works, &ic.; — Gregory's Mechan-
ics, vol. i. ; — Young's Natural Philosophy, vol. i.; — Ilydraulia, or an
Account of the Water Works of London, 8vo. 1835 ; — Bossut, Traitc
Theoretique et Experimental d^ Hydrodynumique, 1771, &c. ; — Du
BuAT Trait'ed^ Hydravlique, et Pyrodynamiquc, 1786, &c.; — Ven-
TURi, Rlcherches Experimentales sur Ics Fluides, 1797; — Rees'
Cyclopedia, article Water; — Edinburgh Encyclopedia, article Hydro-
dynamics ; — and the Hydraulic Works of Mariotte, Guglielmi-
Ni, MiCHALOTTi, D. and J. Bernoulli, D' Alembert, Fon-
TANA, M. Young, Prony, Vince, Juan, Eytelwein, &c.
CHAPTER XVIII.
ARTS OF COMBINING FLEXIBLE FIBRES.
Theory of Twisting, Rope Making, Hemp Spinning. Cotton Man
nfacture. Elementary Inventions, Batting, Carding, Drawing, Rov-
ing, Spinning, Mule Spinning, Warping, Dressing, Weaving, Twil-
ling, Double Weaving, Cross Weaving, Lace, Carpeting, Tapestry,
Velvets, Linens. Woollens. Felting. Paper Making. Book-
binding.
Theory of Tivisting. — The strength of cordage, which
is employed in uniting bodies, and the utility of flexible
textures, which serve for furniture, or for clothing, de-
pend, principally, upon the friction, or lateral adhesion,
produced by the twisting and intermixture of their constit-
uent fibres.
A twisting cord is not so strong as the fibres which
compose it, supposing the fibres and cord to be of the
same length. The object of twisting is, to connect sue
cessive numbers of short fibres, in such a manner, that
besides the mutual pressure which their own elasticity
causes them to exert, any additional force, applied in the
direction of the length of the aggregate, may tend to bring
their parts into closer contact, and augment their adhesion
.0 each other. The simple art of tying a knot, and the
ROPE-MAKING. 165
more complicated processes of spinning, rope-making,
weaving, and felting, derive most of their utility from this
principle.
By considering the effect of a force, which is counter-
acted by other forces, acting obliquely, it will be seen,
that the operation of twisting has a useful effect, in bind-
ing the parts of a rope, or thread, together ; and also, that
it has an inconvenience, in causing the strength of the
fibres to act with a mechanical disadvantage. The great-
er is the obliquity of the fibres, the greater will be their
adhesion to each other, but the greater, also, will be their
immediate strain, or tension, when a force acts upon them,
in the direction of the whole cord. From this, it follows,
that, after employing as much obliquity, and as much ten-
sion, as is sufficient to connect the fibres firmly together,
all that is superfluously added tends to w-eaken the cord,
by overpowering the primitive cohesion of the fibres, in
the direction of their length.
The mechanism of simple spinning is easily understood.
Care is taken, where the hand is employed, to intermix
the fibres sufficiently, and to engage their extremities, as
much as possible, in the centre ; for, it is obvious, that, if
any fibre were wholly external to the rest, it could not be
retained in the yarn. In general, however, the materials
are, previously, in such a state of intermixture, as to ren-
der this precaution unnecessary.
Rope Making. — A single thread of yarn, consisting of
fibres twisted together, has a tendency to untwist itself,
the external parts being strained, by extension, and the
internal parts, by compression ; so that the elasticity of all
the parts resists, and tends to restore the thread to its
natural state. But, if two such threads, similarly twisted,
are retained in contact, at a given point of the circumfer-
ence of each, this point is rendered stationary, by the
opposition of the equal forces, acting in contrary direc-
tions, and becomes the centre, round which both threads
are carried, by the forces which remain ; so that they con-
tinue to twist round each other, till the new combination
causes a tension, capable of counterbalancing the remain-
ing tension of the original threads. Three, four, or more,
166 COMBINING FLEXIBLE FIBRES.
threads may be united, nearly in the same manner. A
strand^ as it is called by rope-makers, consists of a con-
siderable number of yarns, thus twisted together, gener-
ally from sixteen to twenty-five ; a halser consists of three
strands ; a shroud^ of four ; and a cable^ of three halsers,
or shrouds. Shroud-laid cordage has the disadvantage
of being hollow in the centre, or else of requiring a great
change of form in the strands, to fill up the vacuity ; so
that, in undergoing this change, the cordage stretches,
and is unequally strained. The relative position, and the
comparative tension, of all the fibres, in these complicated
combinations, are not very easily determined by calcula-
tion ; but, it is found, by experience, to be most advan-
tageous for the strength of ropes, to twist the strands,
when they are to be compounded, in such a direction, as
to untw^ist the yarns, of w^hich they are formed ; that is, to
increase the twist of the strands themselves ; and, proba-
bly, the greatest strength is obtained, when the ultimate
obhquity of the constituent fibres is least, and the most
equable.*
A very strong rope may, also, be made, by twisting
five or six strands round a seventh, as an axis. In this
case, the central strand, or heart, is found, after much
use, to be chafed to oakum. • Such ropes are, however,
considered unfit for rigging, or for any use, in which they
are liable to be frequently bent.
Ropes are most commonly made of hemp ; but various
other vegetables are occasionally employed. The Chi-
nese even use w^oody fibres ; and the barks of trees fur-
nish cordage to other nations. In spinning the yarn, in
the piocess of rope-making, the hemp is fastened round
the waist of the workman ; one end of it is attached to a
wheel, turned by an assistant, and the spinner, walking
backwards, draws out the fibres with his hands. When
one length of the walk has been spun, it is immediately
reeled, to prevent its untwisting. The machines, employ-
ed in continuing the process of rope-making, are mostly
of simple construction ; but both skill and attention are
* Young's Natural Philosophy, vol. i. Lect. xvi.
HEMP-SPINNING. COTTON MANUFACTURE. 167
required, in applying them, so as to produce an equable
texture, in every part of the rope. The tendency of two
strands to twist, in consequence of the tension, arising from
the original twist of the yarns, is not sufficient to produce
^n equilibrium, because of the friction and rigidity to be
overcome. Hence, it is necessary to employ force, to
assist this tendency, and the strands, or ropes, will after-
wards retain, spontaneously, the form which has thus been
given them. The largest ropes, even, require external
force, in order to make them twist at all.
The constituent ropes of a common cable, w^hen sepa
rate, are stronger than the cable, in the proportion of about
four to three ; and a rope, worked up from yarns, one hun-
dred and eighty yards in length, to one hundred and thirty-
five yards, has been found to be stronger, than when reduc-
ed to one hundred and twenty yards, in the ratio of six to
five. The difference is owing, partly, to the obliquity of
the fibres, and, partly, to the unequal tension, produced
by twisting.*
Hemp Spinning. — The desideratum of spinning hemp,
by machinery, has been attained by Mr. Treadwell, in his
machines for that purpose, now at work, at the Charles-
town Navy Yard, and elsewhere. By this invention, the
hemp is drawn out to the requisite size, by a long series
of teeth, fixed upon a revolving belt, and afterwards twist-
ed, by the revolutions of the machine. The equality, or
uniform size, of the yarn, is ensured, by a roller, or small
wheel, which rests upon the part just twisted, and which
rises, or is pushed up, if the twist becomes too large, and
moves a comb, which immediately falls, and intercepts
the superfluous part of the fibres. On the other hand, if
the twist becomes too small, the roller descends, and, in
so doing, increases the rapidity of the machine, and causes
it to supply the hemp faster.
COTTON MANUFACTURE.
When the fibres of cotton, wool, or flax, are intended
to be woven, they are reduced to fine threads, of uniform
* Young's Natural Philosophy, vol. i. Lect. xvL
168 COxMBINING FLEXIBLE FIBRES.
Size, by the well-known process o( spinning. Previous-
ly to the middle ot the last century, this process was per-
formed by hand, with the aid of the common spinning-
wheel. Locks of cotton, or wool, previously carded,
were attached to a rapidly-revolving spindle, driven by
a large wheel, and were stretched or draw^n out by the
hand, at. the same time that they were twisted by the
spindle, upon which they were afterwards wound. Flax,
the fibres of which are longer, and more parallel, was
loosely wound upon a distaft', from which the fibres were
selected, and drawn out by the thumb and finger, and, at
the same time, were twisted by flyers, and wound upon
a bobbin, which revolved with a velocity, somewhat less
than that of the flyers.
The manufacture of flexible stufls, by means of machin-
ery, operating on a large scale, is an invention of the last
century. Ahhough of recent date, it has given birth to
some of the most elaborate and wonderful combinations
of mechanism, and already constitutes, especially in Eng-
land, and in this country, an important source of national
wealth and prosperity.
Elementary Inventions. — The character of the machin-
ery which has been applied to the manufacture of cotton,
at different times, has been various. There are, howev-
er, several leading inventions, upon which most of the
essential processes are founded, and which have given to
their authors a greater share of celebrity than the rest.
These are, 1. The spinning-jenny. This machine was
invented by James Hargreaves,* in 1767, and, in its
simplest form, resembled a number of spindles, turned by
a common wheel, or cylinder, which was worked by
hand. It stretched out the threads, as in common spin-
ning of carded cotton. 2. The water spinning-frame^
'nvented by Richard Arkwright, in 1769. The essen-
tial, and most important, feature in this invention con-
sists in the drawing out, or elongating, of the cotton, by
causing it to pass between successive pairs of rollers,
which revolve, with different velocities, and which act as
* Mr. Guest, in a late work, attributes the invention, botli of the jen-
»y, and water spinning-frame, to Thomas Highs, of Leigh, England
BATTING. 169
substitutes for the finger and thumb, as applied in common
spinning. These rollers are combined with the spindle
and flyers of the common flax wheel. 3. The mule.
This was invented by Samuel Crompton, in 1779. It
combines the principles of the two preceding inventions,
and produces finer yarn, than that which is spun in either
of the other machines. It has now nearly superseded
the jenny. 4. The power-loom for weaving, by water or
steam power, which was introduced about the end of the
eighteenth century, and has received various modifica-
tions.
The foregoing fundamental machines are used in the
same, or different establishments, and for different pur-
poses. But, besides these, various auxiliary machines are
necessary, to perform intermediate operations, and to pre-
pare the material, as it passes from one stage of the man-
ufacture to another. The number of these machines, and
the changes, and improvements, which have been made in
their construction, from time to time, render it impossible
to convey, in a work hke the present, any accurate idea
of their formation, in detail. A brief view, however, of
the offices which they severally perform, may be taken, by
following the raw material, through the principal changes
which it undergoes, in a modern cotton-factory, founded
and improved upon the general principles of Arkwright.
Batting. — The cotton, after having been cleared from
its seeds, at the plantation, by the operation of ginning.,
described on page 111, Vol. I., is compressed into b^gs,
for exportation, and arrives at the factory, in a dense and
matted mass. The first operation to which it is submitted
has, for its object, to disentangle the fibres, and restore the
cotton to a light, open, and uniform, state. For this pur-
pose, after being weighed out, it is submitted to the ope-
ration of a machine, called a picker., or of another, de-
nominated a batter. In some of these machines, it is
subjected to the action of a series of pins ; in others, to a
sort of blunt knives, revolving with great rapidity ; the
effect of which is, to beat up and separate the fibres, to
disengage their unequal adhesionS; and to reduce the whole
to a very light, uniform, flocculent, mass.
II. In XII.
170 COMBINING FLEXIBLE FIBRES.
Carding. — The cotton next passes to the carding-ma-
chines, of which, when there are two, the first is called
the breaker, and the second, ihe finisher. In this opera-
tion, the cotton is carried over the surface of a revolving
cylinder, which is covered with card-teeth of wire, and
which passes in contact with an arch, or part of a con-
cave cylinder, similarly covered with teeth. From this
cylinder, it is taken off by another, called the doffing cyl-
inder, which revolves in an opposite direction ; and from
this, it is again removed, by the rapid vibrating movement
of a transverse comb, otherwise called the doffing -plate,
moved by cranks. It then exists in the state of a flat,
uniform, fleece, or lap, which, after passing the breaker,
undergoes the process of plying, or doubling, by causing
it to perform a certain number of revolutions upon a cyl-
inder, or a perpetual cloth. It is then carded a second
time, by the finisher, and the fleece, after being taken off
from this machine, is draw^n by rollers, through a hollow
cone, or trumpet mouth, which contracts it to a narrow
band, or sliver, and leaves it coiled up in a tin can, ready
for the next operation. The process of carding serves to
equalize the substance of the cotton, and to lay its fibres
somewhat in a more parallel direction.
Drawing. — The slivers of cotton are next elongated,
by the process of drawing. This operation is the ground-
work, or principle, of Arkwright's invention, and is used
in the roving, and spinning, as well as in the drawing-
frame. It is an imitation of what is done by the finger
and thumb, in spinning by hand, and is performed, by
means of two pairs of rollers. The upper roller, of the
first pair, is covered with leather, w^hich, being an elastic
substance, is pressed, by means of a spring, or weight.
The lower roller, made of metal, is fluted, in order to
keep a firm hold of the fibres of cotton. Another similar
pair of rollers are placed near those which have been de-
scribed. The second pair, moving with a greater veloc-
ity, pull out the fibres of cotton from the first pair of rol-
lers. If the surface of the last pair move at twice, or
thrice, the velocity of the first pair, the cotton will be
di-awn twice, or thrice, finer than it was before. Thij
ROVING. 171
relative velocity is called the draught ot the machine,
This mechanism being understood, it will be easy to con-
ceive the nature of the operation of the drawing-frame.
Several of the narrow ribands, or slivers, from the cards,
(sometimes termed card-ends ,) by being passed through
a system of rollers, are thereby reduced in size. By
means of a detached, single pair of rollers, the several re-
duced ribands are pliedj or united into one sliver.
The operations of drawing and plying serve to equalize,
still further, the body of cotton, and to bring its fibres
more into a longitudinal direction. These slivers are
again combined, and drawn out, so that one sliver of the
finished drawing contains many phes of card-ends. Hith-
erto, the cotton has acquired no twist, but is received into
movable tin cans, or canisters, similar to those used for
receiving the cotton from the cards.
Roving. — The operation of roving communicates the
first twist to the cotton. It is performed by a machine,
called the roving-frame ^ or double-speeder. The tin cans,
containing the shvers of cotton, are placed upon this ma-
chine, and are made to revolve, slowly, about their axes,
so as to produce a shght degree of twisting. The slivers
then pass again, through several pairs of rollers, moving
with different speeds, and are thus still further attenuated,
by drawing. They are then slightly spun, by the revolu-
tion of flyers, and are wound upon the bobbins of the
spindles, in the form of a loose, soft, imperfect, thi-ead,
denominated the roving.
The mechanism of the double speeder is complicated,
and interesting, and great ingenuity has been displayed, in
overcoming the difficulties of hs construction. In order
that the yarn, or roving, may be wound upon the bobbins,
in even, cylindrical, layers, it is necessary, that the spindle
rail, or horizontal bar, which supports the spindles, should
continually rise and fall, with a slow alternate motion
This is effected by heart-wheels, or cams, in the interio*
of the machine. Again, since the collective size of tht
Dobbin is augmented, by the addition of each layer oi
roving, it is obvious, that, if the axis of the bobbin re
volved, always, with the same velocity, the thread of rov
172 COMBINING FLEXIBLE FIBRES.
ing would be broken, in consequence of being wound up
too fast. To prevent this accident, the velocity of the
spindles, and, likewise, the motion of the spindle-rail, is
obliged gradually to diminish, from the beginning to the
end of an operation. This diminution of speed is effect-
ed, by transmitting the motion, both to the spindle-rail,
and to the bobbins, through two opposite cones, one of
which drives the other with a band, the band being made
to pass, slowly, from one end to the other of the cones,
and thus continually to alter their relative speed, and
cause a uniform retardation of the velocity of the moving
parts.* As the roving is not strong enough to bear any
violence, the spindles, which support the bobbins, are
geared to each other, so as to prevent any deviation from
the proper velocity.
A more simple form of the roving-frame has been in-
vented,! in which the gearing is dispensed with, as well
as the pair of cones, which regulates the motion of the
bobbins. In this machine, the bobbins are not turned by
the rotation of their axes, but by friction, applied to their
surface, by small wooden cylinders which revolve in con-
tact with them. In this way, the velocity of the surface
of the bobbin will always be the same, whatever may be
its growth, from the accumulation of roving, so that the
winding goes on, at an equable rate. To prevent the rov-
ing from being stretched, or broken, in its passage from
the drawing rollers to the bobbins, it is made to pass
through a tube, w^hich has a rapid rotation, and which
twists it, in the middle, into a cord of some firmness. It
is again untwisted, as fast as it escapes from the tube, and
is wound upon the bobbins, in the form of a dense, even,
cord, but without any twist.
Spinning. — The bobbins, which contain the cotton, in
A state of roving, are next transferred to the spinning-
frame. It is here once more drawn out by rollers, and
twisted by flyers, so that the spinning is little more than
* Instead of band c-oi.es, an ingenious mode of using geared cones,
now introduced in several American factories, has already been de
escribed, page 60.
t By Mr. Danforth, of Massachusetts.
MULE-SPINNING. 175
•
a repetition of the process gone through, in making the
roving, except that the cotton is now twisted into a strong
thread, and cannot any longer be extended, by drawing.
The flyers of the spinning-frame are driven by bands,
which receive their motion, in some cases, from a hori-
zontal fly-wheel, and, in others, from a longitudinal cylin-
der.* As the thread is sufliciently strong not to break
with a slight force, the resistance of the bobbins, by fric-
tion, is rehed on to wind it up, instead of having tlie spin-
dles geared together, and turned with an exact velocity,
as they are in the common double-speeder. In the spin-
ning frame, the heart-motion is retained, to regulate the
rise and fall of the rail ; and, in those frames which spin
the woof, or filling, it is applied, by a progressive sort of
cone, the section of which is heart-shaped, and which
acts, remotely, to distribute the thread, in conical layers,
upon the bobbins, that it may unwind the more easily,
when placed, afterwards, in the shuttle.
Mule Spinning. — The processes of water-spinning,
already described, are adequate to produce yarns, of suf-
ficient fineness for ordinary fabrics. But, for producing
threads of the finest kind, another process is necessary,
which is called stretchings and which is analogous to that
which is performed, with carded cotton, upon a commr^n
spinniiag-wheel. In this operation, portions of yarn, sev-
eral yards long, are forcibly stretched, in the direction r^
their length. It differs, therefore, from the operation €>*'
drawing, in which a few inches, only, are extended at •
time. The stretching is performed, with a view to elop-
gate and reduce those places in the yarn, which have ^
greater diameter, and are less twisted, than the other parts
so that the size and twist of the thread may become uni-
form throughout. To effect the process of stretching,
the spindles are mounted upon a carriage, which is moved,
back and forwards, across the floor ; receding, when the
tln-eads are to be stretched, and returning, when they are
to be wound up. The yarn, produced by mule-spinning,
is more perfect than any other, and is employed in the
* The latter method, which had gone into disuse, is beginnmg to be
revived, and to be considered most advantageous.
15*
174 COMBINING FLEXIBLE FIBRES.
m
fabrication of the finest artiJes. The sewing-thread,
>pun by mules, is a combination of two, four, or six, con-
stituent threads, or phes. Threads t>ave been produced,
of such fineness, that a pound of cotton has been calculat-
ed to reach one hundred and sixty-seven miles.
IVarping. — The first step, preparatory to weaving, is
to form a warp^ which consists of parallel threads, con-
tinued through the whole length of the intended piece, and
sufficient, in number, to constitute its breadth. It was,
formerly, the practice to attach the threads to as many
pins, and to draw them out, to the required length. But,
as this method required too much room, a warping ma-
chine was subsequently used, in which the mass of threads,
intended to constitute a warp, w^as wound in a spiral course,
upon a large revolving frame, which rose and fell, so as
to produce the spiral distribution.
These methods are now superseaeu, n this countiy
by Moody's warping-machine,* an ingerious piece ot
mechanism, in which a number of bobbins, eqjal to one
eighth part of the number of threads in the intended warp,
are arranged upon the surface of a con ".ave frame. The
threads pass through a reed, which separates the alternate
threads, as they are to be kept in the loom ; after which,
they are wound upon a beam, with rods interposed at the
end, to preserve the separation. But the most ir4/erest-
ing part of the mechanism is a contrivance for stopping
the machine, if a single thi^ead of the warp breaks. To
effect this object, a small steel weight, or flattened wire,
is suspended, by a hook, from each thread, so that it falls,
if the thread is broken. Beneath the row of weights, a
cylinder revolves, furnished with several projecting ledges .
extending its whole length, parallel to the axis. Whe.
one of the w^eights falls, by the breaking of its thread, i
intercepts one of the ledges, and causes the cyhnder to
exert its force upon an elbow, or toggle-joint, which dis-
engages a clucch, and stops the machine. After the thread
is tied, and the weight raised, the machine proceeds.
* Mr. Paul Moody, formerly of Walthara, and now of Lowell, is the
inventor of this machine ; likewise of the spinning-frame, which winda
the woof in conical layers ; and of great improvements in the roving
frame, the dressing-frame, &c.
DRESSING. WEAVING. 176
Dressing. — As the threads, which constitute the warp,
are Hahle to much friction, in the process of weaving, they
are subjected to an operation, called dressing, the object
of which is, to increase their strength and smoothness, by
agglutinating their fibres together. To this end, they are
pressed between rollers, impregnated with mucilage, made
of starch, or some gelatinous material, and, immediately
afterwards, brought in contact with brushes, which pass
repeatedly over them, so as to lay down the fibres in one
direction, and remove the superfluous mucilage from them.
They are then dried, by a series of revolving fans, or by
steam-cylinders, and are ready for the loom.
Weaving. — Woven textures derive their strength from
he same force of lateral adhesion, which retains the twis-
ed fibres of each thread in their situations. The man-
ner, in which these textures are formed, is readily under-
stood. On inspecting a piece of plain cloth, it is found
to consist of two distinct sets of threads, running perpen-
dicularly to each other. Of these, the longitudinal threads
constitute the warp., while the transverse threads are called
the woof., t^^ft, or fillings and consist of a single thread,
passing backwards and forwards. In weaving with the
common loom, the warp is wound upon a cylindrical beam,
or roller. From this, the threads pass through a har-
ness,- composed of movable parts, called the heddles, of
which there are two or more, consisting of a series of
vertical strings, connected to frames, and having loops,
through which the warp passes. When the heddles con-
sist of more than one set of strings, the sets are called
leaves. Each of these heddles receives its portion of the
alternate threads of the warp ; so that, when they are
moved, reciprocally, up and down, the relative position
of the alternate threads of the warp is reversed. Each
time that the warp is opened, by the separating of its al-
ternate threads, a shuttle, containing the woof, is thrown
across it, and the thread of a w^oof is immediately driven
into its place, by a frame, called a lay, furnished with thin
reeds, or wires, placed among the warp, like the teeth of
a comb. The woven piece, as fast as it is completed, is
wound up on a second beam, opposite to the first.
176
COMBJNING FLEXIBLE FIBRES.
Power looms, driven by water, or steam, although a
late invention, are now universally introduced into manu-
factories of cotton and woollens. As the motions of the
loom are, chiefly, of a reciprocating kind, they are produ-
ced, in some looms, by the agency of cranks, and in oth-
ers, by cams, or wipers, acting upon weights, or springs.
Twilling. — In the mode of plain weaving, last describ-
ed, it will be observed, that every thread of the warp
crosses at every thread of the woof, and vice versa. In
articles, which are twilled^ or 'ticeeled^ this is not the case ;
for, in this manufacture, only the third, fourth, fifth, sixth,
&c., threads cross each other, to form the texture. In
the coarsest kinds, every third thread is crossed ; but, in
finer fabrics, the intervals are less frequent, and, in some
very fine twilled silks, the crossing does not take place, till
the sixteenth interval. In Fig 178, is shown a magnified
Fig. 178.
section of a piece of plain cloth, in which the woof passes,
alternately, over and under every thread of the warp. In
Fig. 79, is a piece of twilled cloth, in which the thread
Fk. 179.
r<y:
ro
toz
ro
of the woof passes, alternately, over four, and under one,
of the threads of the warp, and performs the reverse, in
its return. To produce this effect, a number of leaves
of heddles are required, equal to the number of threads
contained in the interval, between each intersection, in-
clusive. By the separate movements of these, the warp
is placed in the requisite positon, before each stroke of
the shuttle. A loom, invented in this country, by Mr.
Batchelder, of Lowell, has been applied to the weaving
-jf twilled goods, by water-power.
Twilled fabrics are thicker than plain ones, when of the
same fineness, and more flexible, when of the same thick-
ness. They are also more suceptible of ornamental va
DOUBLE-WEAVING. CROSS-WEAVlMr.
J 77
riajions. Jeans, dimities, serges, &c.,are specimens of
this kind of texture.
Double Weaving. — In this species of weaving, the fa-
bric is composed of two webs, each of which consists of
a separate warp, and a separate woof. .The two, however,
are interwoven, at intervals, so as to produce various fig-
ures. The junction of the two webs is formed, by pass-
ing them, at intervals, through each other ; so that each
particular part of both is sometimes above, and sometimes
below. It follows, that, when different colors are employ-
ed, as in carpeting, the figure is the same, on both sides,
but the color is reversed. A section of double cloth is
shown in Fig. 180.
F\2. 180.
The weaving of double cloths is commonly performed,
by a complicated machine, called a draw-loom., in which
the w^eaver, aided by an assistant, or by machinery, has
the command of each particular thread, by its number.
He works by a pattern, in which the figure before him is
traced, in squares, agreeably to which the threads to be
moved are selected, and raised, before each insertion of
the woof. Kidderminster carpets, and Marseilles quilts,
are specimens of this mode of weaving.
Cross Weaving. — This method is used, to produce the
lightest fabrics, such as gauze, netting, catgut, &c. In the
kinds of weaving which have been previously described,
the threads of the warp always remain parallel to each oth-
er, or without crossing. But, in gauze-weaving, the two
threads of warp, which pass between the same splits of the
reed, are crossed over each other, and partially twisted like
a cord, at every stroke of the loom. They are, however,
twisted to the right and left, alternately, and each shot, or
insertion of the woof, preserves the twist which the warp
has received. A great variety of fanciful textures are pro-
178 COMBINING FLEXIBLE FIBRES.
duced, by variations of the same general plan. Fig. 1.81,
represents the cross-weaving, used in comnaon gauze.
Fig. 181.
Lace. — Lace is a complicated, ornamental, fabric,
formed of fine threads of linen, cotton, or silk. It consists
of a net- work of small meshes, the most common form
of which is hexagonal. In perfect thread-lace, four sides
of the hexagon consist of threads which are twisted, while,
in the remaining two, they are simply crossed. Lace has
been commonly made upon a cushion, or pillow, by the
slow labor of artists. A piece of stiff parchment is stretch-
ed upon the cushion, having holes pricked through it, in
which pins are inserted- The threads, previously wound
upon small bobbins, are woven round the pins, and twist-
ed, in various ways, by the hands, so as to form the requir-
ed pattern. The expensiveness of the different kinds of
lace is proportionate to the tediousness of the operation.
Some of the more simple fabrics are executed with rap-
idity, while others, in which the sides of the meshes are
plaited, as in the Brussels lace, and that made at Valen-
ciennes, are difficult, and bear a much greater price.
The cheaper kinds of lace have long been made by
machinery ; and, recently, the invention of Mr. Heath-
coat's lace-machine has effected the fabrication of the
more difficult, or twisted lace, with precision and des
patch. This machine is exceedingly compHcated and
ingenious, and is now in operation in this country, and in
France, as well as in England.
Carpeting. — Carpets are thick textures, composed,
wholly or partly, of wool, and wrought by several dissimi-
lar methods. The simplest mode is that used in weav-
ing the Venetian carpets, which is a plain texture, com-
Dosed of a striped woollen warp, on a thick woof of
linen thread. Kidderminster carpeting is composed by
two woollen webs, which intersect each other, in such a
manner, as to produce definite figures. Brussels carpet
TAPESTRY. VELVETS. ' 179
mg has a basis, composed of a warp and woof, of strong
linen thread. But, to every two threads of linen, in the
warp, there is added a parcel of about ten threads of
woollen, of different colors. The linen thread never
appears on the upper surface ; but parts of the woollen
threads are, from time to time, drawn up in loops, so as
to constitute ornamental figui^es, the proper color being,
e:.ch time, selected from the parcel to which it belongs.
A sufficient number of these loops is raised, to produce a
uniform surface, as seen in Fig. 182 ; and to render them
Fk. 182.
equal, each row passes over a wire, which is subsequent-
ly withdrawn. In some cases, the loops are cut through
with the end of the wire, which is sharpened for the pur-
pose, so as to cut off the threads, as it passes out. Ir
forming the figure, the weaver is guided by a pattern,
which is drawn in squares, upon a paper. Turkey car-
pets appear to be fabricated upon the same general prin-
ciples, as the Brussels, except that the texture is all wool-
len, and the loops larger, and always cut.
Tapestry. — The name of tapestry is given to certain
deUcate and complicated fabrics, in which the forms and
colors of natural objects are produced, with such accura-
cy, as to resemble fine paintings. The mode of texture
used, to produce this effect, is, in many respects, analo
gous to that by which the finer carpetings are made. The
minuteness, however, of the constituent parts, causes the
sight of the texture to be lost, in the general effect of the
piece. The fabrication of tapestry is slow, intricate, and
very expensive. The most celebrated manufactory is that
established by the family of Gobelins, and kept up by
their successors, at Paris.
Velvets. — The fine soft nap, by which velvet is cov-
ered, is produced by a method, not unhke that which is
used in carpeting and tapestry. It is formed of a part
180 COMBINING FLEXIBLE FIBRES.
of the threads of the warp, which the workman puts, in
loops, on a long, channelled wire. Before the wire is
withdrawn, the row of loops is cut open, by a sharp steel
nistrument which is drawn along the channel of the wire.
Various other fabrics of silk, cotton, and wool, such as
thicksets, plushes, corduroys, velveteens, &c., are cut in
a similar manner.
Cotton counterpanes are woven with two shuttles, one
containing a much coarser woof than the other. The
coarser of the threads is picked up, at intervals, with an
iron pin, whtch is hooked at the point, thus forming knobs^
which are made to constitute regular figures.
In cotton fabrics, the web, when taken from the loom.
IS covered with an irregular nap, or down, formed by the
projecting ends of the fibres. This is removed, in the
finest articles, by burning it off, the heat being so man-
aged, as not to injure the texture of the cloth. The oper-
ation is performed, by drawing the web, very rapidly, over
an iron cylinder which is kept constantly red hot, by a
fire within it. The velocity of the cloth prevents it from
burning, while the loose filaments, which constitute the
nap, are singed off. The flame of coal-gas has, of late,
been applied to the same purpose.
Linens. — This name belongs to fabrics, which are man-
ufactured from flax ; but those made of hemp are similar
in their properties, except in fineness. The length and
comparative rigidity, of the fibres of flax, present difli-
culties, in the way of spinning it, by the machinery which
is used for cotton and wool. It cannot be prepared, by
carding, as these other substances are, and the rollers
are capable of drawing it but very imperfectly. The
subject of spinning flax, by machinery, has attracted
much attention, and the Emperor Napoleon, at one time,
oflered a reward of a million of francs, to the inventor of
the best machine, for this purpose. Various individuals,
both in this country, and in Europe, have succeeded in
constructing machines, which spin coarse threads of linen,
sufficiently well, and with great rapidity. But the manu-
facture of fine threads, such as those used for cambrics
and lace, continues to be performed, by hand, upon the
ancient spinning-wheel.
WOOLLENS. 181
Linen was manufactured by the Egyptians, probably,
one thousand five hundred years before Christ. Some
of it was of exceeding fineness. Vast quantities, in the
form of mummy-cloths, still remain.
WOOLLENS.
The fibres of wool, being contorted and elastic, are
drawn out and spun, by machinery, in some respects sim-
ilar to that used for cotton, but differing in various partic-
ulars. Independently of the quality of fineness, there
are two sorts of wool, which afford the basis of different
fabrics, the long wool, and the short. Long wool is that,
in which the fibres are rendered parallel, by the process
of combing. It is also known by the name of icorstedj
and is the material, of which camlets, bombazines, &c.,
are made. Short wool is prepared, by carding, like cot-
ton, and is used, in different degrees of fineness, for broad-
cloths, flannels, and a multitude of other fabrics. This
wool, when carded, is formed into small, cylindrical rolls,
which are joined together, and stretched, and spun, by a
slubbing, or roving, machine, and a jenny, or mule ; in
both of which, the spindles are mounted on a carriage,
which passes backwards and forwards, so as to stretch
the material, at the same time that it is twisted. On ac-
count of the roughness of the fibres, it is necessary to
cover them with oil, or grease, to enable them to move
freely upon each other, during the spinning and weaving.
After the cloth is woven, the oily matter is removed, by
scouring, in order to restore the roughness to the fibres,
preparatory to the subsequent operation of fulling.
In articles which are made of long wool, the texture
is complete, when the stuff issues from the loom. The
pie,ces are subsequently dyed, and a gloss is communica-
ted to them, by pressing them between heated melalhc
surfaces. But, in cloths made of short wool, the weav-
ing cannot be said to have completed the texture. When
the web is taken from the loom, it is too loose and open,
and, consequently, requires to be submitted to another op-
eration, called fulling. This is performed by a fulling-
mill, in which the cloth is immersed in water, and subject-
II. 16 XII.
182 COMBINING FLEXIBLE FIBRES.
ed to repeated compressions, by the action of large beaters,
formed of wood, which repeatedly change the position of
the cloth, and cause the fibres to felt, and combine more
closely together. By this process, the cloth is reduced
in its dimensions, and the beauty and stability of the tex-
ture are greatly improved. The tendency to become
thickened, by fulling, is peculiar to wool and hair, and
does not exist in the fibres of cotton, or flax. It depends
on a certain r€ughness of these animal fibres, which per-
nits motion, in one direction, while it retards it, in anoth-
er. It thus promotes entanglements of the fibres, which
serve to shorten and thicken the woven fabric. Before
the cloth is sent to the fulling-mill, it is necessary to
cleanse it from all the unctuous matter, which was ap-
plied, to prepare the fibres for spinning.
The nap, or downy surface, of broadcloths, is raised,
by a process, which, while it improves the beauty, tends
somewhat to diminish the strength, of the texture. It is
produced, by carding the cloth, with a species of burrs,
the (ruit of the common teazle, {Dipsacus fullonum^)
which is- cultivated for the purpose. This operation ex-
tricates a part of the fibres, and lays them in a parallel
direction. The nap, composed of these fibres, is then
cut off, to an even surface, by the process of shearing.
This is performed in various ways ; but in one of the
most common methods, a large spiral blade revolves,
rapidly, in contact with another blade, while the cloth is
stretched over a bed, or support, just near enough for
the projecting filaments to be cut off, at a uniform length,
while the main textur^^ remains uninjured.
FELTING.
The texture of modern hats, which are made of fur and
wool, depends upon the process oi felting^ which is sim-
ilar to that of fulling, already described. The fibres of
these substances are rough, in one direction only ; a cir-
cumstance which may be perceived, by passing a hair
through the figures, in opposite directions. This rough-
ness allows the fibres to glide among each other, so that,
when the mass is agitated, the anterior extremities shde
PAPER-MAKING. 183
forward, in advance of the body, or posterior half of the
hair, and serve to entangle, and contract, the whole mass
together. The materials, commonly used for hat-making,
are the furs of the beaver, seal, rabbit, and other animals,
and the wool of sheep. The furs of most animals are
mixed with a longer kind of thin hair, which is obliged to
be first pulled out, after which, the fur is cut off, with a
knife. The materials to be felted are intimately mixed
together, by the operation of bowings which depends on
the vibrations of an elastic string ; the rapid alternations
of its motion being pecuHarly well adapted to remove all
irregular knots and adhesions, among the fibres, and to
dispose them in a very hght and uniform arrangement.
This texture, when pressed under cloths and leather,
readily unites into a mass of some firmness. This mass
is dipped into a liquor, containing a little sulphuric acid ;
and, when intended to form a hat, it is first moulded into
a large conical figure, and this is afterwards reduced in
its dimensions, by working it, for several hours, with the
hands. It is then formed into a flat surface, with several
concentric folds, which are still further compacted, in or-
der to make the brim, and the circular part of the crown,
and forced on a block, wiiich serves as a mould, for the
cylindrical part. The nap, or outer portion of the fur,
is raised with a fine wire brush, and the hat is subsequent-
ly dyed and stiffened, on the inside, with glue.
An attempt has been made, and, at one time, excited
considerable expectation in England, to form woollen
cloths by the process of felting, without spinning or weav-
ing. Perfect imitations of various cloths, were produced ;
but they were found deficient in the firmness and dura-
bihty, which belongs to woven fabrics.
PAPER-MAKING.
The combination of flexible fibres, by which paper is
produced, depends on the minute subdivision of the fibres,
and their subsequent cohesion. Linen and cotton rags
are the common material, of which paper is made ; but
hemp, and some other fibrous substances, are used for
the coarser kinds. These materials, after being washed,
184 COMBINING FLEXIBLE FIBRES
are subjected to the action of a revolving cylinder, the
surface of which is furnished with a number of sharp teeth,
or cutters, which are so placed, as to act against other cut-
ters, fixed underneath the cylinder. The rags are kept
immersed in water, and continually exposed to the action
of the cutters, for a number of hours, till they are minute-
ly divided, and reduced to a thin pulp. During this pro-
cess, a quantity of chloride of lime is mixed with the
rags, the effect of which is to bleach them, by discharging
the coloring matter, with which any part of them may be
dyed, or otherwise impregnated. Before the discovery
of this mode of bleaching, it was necessary to assort the
rags, and select only those which were white, to consti-
tute white paper. If, however, the bleaching process be
carried too far, it injures the texture of the paper, by cor-
roding and weakening the fibres.
The pulp, composed of the fibrous particles, mixed with
water, is transferred to a large vat, and is ready to be made
into paper. The workman is provided with a mouldy
whiqh is a square frame, with a fine wire bottom, resem-
bling a sieve, of the size of the intended sheet. With
this mould, he dips up a portion of the thin pulp, and holds
it in a horizontal direction. The water runs out through
the interstices of the wires, and leaves a coating of fibrous
particles, in the form of a sheet, upon the bottom of the
mould. The sheets, thus formed, are subjected to pres-
sure, first between fehs, or woollen cloths, and afterwards
alone. They are then sized, by dipping them in a thin so-
lution of gelatin, or glue, obtained from the shreds and par-
ings of animal skins. The use of the size is to increase
the strength of the paper, and, by filling its interstices,
to prevent the ink from spreading among the fibres, by
capillary attraction. In blotting paper, the usual sizing is
omitted.
The paper, after being dried, is pressed, examined,
selected, and made into quires and reams. Hot-pressed
paper is rendered glossy, by pressing it between hot plates
of polished metal.
Paper is also manufactured by machinery ; and one
of the most ingenious methods is that invented by the
BOOKBINDING. 185
Messrs. Fourdrinier. In this arrangement, instead oi
moulds, the pulp is received in a continual stream, upon
the surface of an endless web of brass wire, which extends
round two revolving cylinders, and is kept in continual
motion forwards, at the same time that it has a tremulous,
or vibrating, motion. The pulp is thus made to form a
long, continual sheet, which is wiped off from the wire
web, by a revolving cylinder, covered with flannel, and,
after being compressed between other cylinders, is finally
wound into a coil, upon a reel, prepared for the purpose.
Another machine for making paper, consists of a hori-
zontal revolving cyhnder of wire web, which is immersed
in the vat, to the depth of more than half its diameter.
The water penetrates into this cylinder, being strained
through the wire web, at the same time depositing a coat
of fibrous particles on the outside of the cylinder, w^hich
constitute paper. The strained water flows oiF, through
the hollow axis of the cylinder, and the paper is wound
off, from the part of the cylinder which is above water,
in the form of a continued sheet.
As a specimen of the rapidity with which paper may
now be manufactured, Mr. Passey, of Birmingham, has
in his possession, a document, the material of which was
in a state of rags, was made into paper, dried, and printed,
in the space of five minutes, in the presence of many
witnesses.
Bookbindings according to the present mode, is per-
formed in the following manner. The sheets are first
folded into a certain number of leaves, according to the
form in which the book is to appear ; viz., two leaves for
fohos, four for quartos, eight for octavos, twelve for duo-
decimos, &c. This is done with a slip of ivory or box-
woodj called a folding-stick. In the arrangement of the
sheets^ the workmen are directed by catchwords or sig-
natures, at the bottom of the pages. When the leaves
are thus folded, and arranged in proper order, they are
usually beaten upon a stone, with a heavy hammer, to
make them solid and smooth, and are then condensed in
a press, or by passing through iron rollers. After this
preparation, they are sewed in a sewing-press, upon
16*
IS6 COMBINING FLEXIBLE FIBRES.
transverse cords, or packthreads, called bands, to receive
which, notches are previously sawed in the back.
The number of bands is usually six to a folio, and
five for quartos, or any smaller size. The backs are
now brushed over with glue, and the ends of the bands
opened, and scraped with a knife, that they may be more
conveniently fixed to the pasteboard sides ; after which,
the back is turned with a hammer, the book being fixed
in a press, between boards, called backing-boards, in
order to make a groove, for admitting the pasteboard
sides.
When these sides are applied, holes are made in them,
for drawing the bands through, the superfluous ends are
cut off, and the parts are hammered smooth. The book
is next pressed, for cutting, which is done by a particu-
lar machine, called the plough, to which is attached a
knife. It is put into a press, called the cutting-press,
betwixt two boards, one of which lies even with the
press, for the knife to run upon ; and the other above,
for the knife to cut against. After this, the pasteboards
are cut square, with a pair of iron shears ; and the colors
are sprinkled on the edges of the leaves, with a brush,
made of hog's bristles.
The pasteboard sides are now covered, by pasting
upon them leather, or whatever other material is intend-
ed to form the outside. The sprinkling, or marbling, of
the covers is performed, with a brush and a coloring li-
quid. The covers are glazed, by applying to them the
white of an egg, and rubbing them with a heated steel-
polisher. A thin piece of morocco is glued upon the
back, to receive the lettering, which is impressed with
gold-leaf and heated types.
Cloth Binding is a recent improvement, in which a
piece of cloth, usually dyed cotton, is embossed with
ornamental figures, bypassing it through a roller-press, be-
tween engraved steel cylinders. It is afterwards pasted
upon the volume, in the same manner as leather. Cloth
binding is executed with more despatch, and at less ex-
pense, than that with leather.
ARTS OF HOROLOGY. 187
Works of Reference. — Gray's Treatise on Spinning Machin-
ery, 8vo. 1819 ; — Duncan's Essay on the Art of Weaving, Svo.
1808 ; — Guest's History of the Cotton Manufacture, 4to. 1823 ; —
BoRGNis' Mechanique Appliquee aux Arts, 1818 ; torn. 7, Machines
a Confectionner les Etoffes ; — Ure, The Cotton Manufacture of Great
Britain, 8vo. 1836 ; — Lardners' Cabinet Cyclopedia, 12mo. vol.
xxii. entitled Silk Manufacture ; — Rees' Cyclopedia, articles Cotton
Manufacture, Woollen Manufacture, &c. ; — ^Edinburgh Encyclope-
dia, articles Cotton Spinning, Cloth Manufacture, &c. Much of the
machinery, invented in this country, is not described in European works.
CHAPTER XIX.
ARTS OF HOROLOGY.
Sun Dial, Clepsydra, Water Clock, Clock Work, Maintaining Power,
Regulating Movement, Pendulum, Balance, Scapement, Descrip-
tion of a Clock, Striking Part, Description of a Watch.
Horology, or the art of measuring time, has received
the attention, and exercised the ingenuity, of mankind,
from the earhest periods. The lapse of thought, and the
routine of ordinary occupation, afford but imperfect indi-
cations of the real passage of time ; and the only exact
standard, by which periods of duration can be estimated,
is that of governed and regular motion.
Sun Dial. — The diurnal movement of the earth, with
relation to the heavenly bodies, is the most perfect stand-
ard of admeasurement, for large periods of time. It is
the only one, by which the brute creation, and the unciv
ilized part of mankind, govern their habits of life. This
motion has been converted to practical use, for measuring
small periods, by the employment of the sun-dial, an in-
vention, apparently, of great antiquity, in which the falling
of a shadow, on a surface opposite to the sun, indicates
the hour of the day. The sun-dial was known to the
ancient Egyptians, Chinese, and Bramins, and was used,
My the latter, for astronomical purposes. It appears,
also, to have been known to the Jews, in the time of
Ahaz, about seven hundred and forty years before Christ.
188 ARTS OF HOROLOGY.
The first sun-dial at Rome was set up by Papiriiis Cur-
sor, about three hundred years before Christ ; previously
to which time, Pliny tells us, there is no mention of any
account of time, but by the sun's rising and setting.
At Athens, there is now standing an octagonal build-
ing, erected by Andronicus Cyrrhestes, and commonly
called the Tower of the Winds. It is shown in Fig. 44
Vol. I. Upon each of the eight sides of this building,
is a flying figure, carved in relief, representing the partic
ula; wind which blew against that side. Upon each side,
was also placed a vertical sun-dial ; the gnomon^ or index,
which cast the shadow, projecting from the side, while the
lines, indicating the hour, were cut upon the wall. On the
top, according to Vitruvius, was the figure of a Triton,
which turned with the wind, in the same manner as a mod-
ern weathercock. The lines of the dial, upon the wall, are
distinctly extant, at the present day ; and, although the
gnomons have disappeared, the places w^here they were
inserted are still visible.
Clepsydra. — Since the sun-dial could be used, only in
the day time, and in clear weather, a different instrument
was invented by the ancients, to be used within doors, at
all times ; and to this was given the name of clepsydra.
The clepsydra was formed by a vessel of water, having a
minute perforation in the bottom, through w^hich the water
issued, drop by drop. It fell into another vessel, in which
a light body floated, having attached to it an index, or
graduated scale. As the water increased in the receiv-
ing vessel, the floating body rose, and, by its regularly
increasing height, furnished an approximation to the cor-
rect indication of time.*
The original clepsydra was but a rude instrument, and
must have given imperfect indications of the true divisions
of time. When the vessel was first filled, the drops must
have fallen faster, owing to the greater height and pres-
* This instrument was invented in Egypt, but was brought into Rome
from Athens. Pompey, while Consul, introduced it into the Roman
Senate House ; and the orators were obliged to limit the length of their
speeclies, by its divisions of time, so that Pompey is designated, by one
of th\e historians, as the first Roman who put bridles upon eloquence.
WATER-CLOCK. CLOCK-WORK. 189
sure of the fluid ; and, in proportion as it became empty,
the dropping would be slower, in consequence of the di-
minution of this pressure. The disadvantage, however,
was remedied, in various ways, by the employment of
two vessels, one of which was kept constantly full, by a
supply from the other ; and thus the water, being always
at the same height, furnished its drops, under an equable
pressure.
Water Clock. — x\n instrument, called a water-clock,
was in use, at a much later date, and was a subject of
extensive manufacture, in some parts of Europe, a few
centuries ago. Several modes of constructing this instru-
ment were devised ; but the following is one of the most
ingenious. A tight, hollow cyhnder, PI. IV. Fig. 4, is
suspended by cords, wound round its axis, which will
unwind, as it runs down. It has its interior divided into
several compartments, situated like the buckets of a wa-
ter-wheel. These compartments communicate with each
other, by a minute aperture, through which water can
pass slowly, from one compartment to another. Before
the machine is put in motion, a small quantity of water
is introduced into the lower compartments. As the cyl-
inder descends, by the unwinding of the cords, it is obliged
to revolve on its axis, until the lower compartments, which
contain the water, have risen so far on the ascending side,
as to produce an equilibrium. It can then unwind no
faster than the water escapes, from one compartment to
another, through the minute apertures. As this requires
a considerable time, the cylinder may occupy a day, if
required, in descending from the top to the bottom of the
frame, to wkich it is attached. And, if the sides of the
frame be marked with the hours of the day, the axis of
the cylinder, as it passes by them, will indicate the time
of the day, with as much accuracy as so imperfect a
machine permits.
Clock Work. — In modern days, all other methods of
measuring time have given place to the equable motion,
produced by the action of machinery on the pendulum
and balance. Timekeepers, constructed on this princi-
ple, began to be known in Europe, about the fourteenth
190 ARTS OF HOROLOGY.
century, but were formed in a rude and imperfect man
ner, until the middle of the seventeenth. Since that pe-
riod, the learning of philosophers, and the ingenuity of
artists, have been extensively applied to their improve-
ment *> and few subjects, connected with the mechanic
arts, have called forth more inventive c.cuteness, elabor-
ate experiment, and exact calculation.
Before proceeding to a description of the entire me-
chanism of a clock, or watch, it will be useful to attend
to some of the general principles, and essential parts, of
a timekeeper. These will be most easily made intelligi-
ble, by directing the attention to the following subjects.
1. The maintaining power. 2. The regulating move-
ment. 3. The method of connection.
Maintaining Power. — The force, which is employed
to sustain the motions of timekeepers, does not require to
be of a pow^erful kind. It must, however, be steady and
uniform, in its action. Gravity and elasticity, applied
through the medium of weights and springs, are the only
means now employed, to communicate motion to these
machines. In clocks, the maintaining force is usually
derived from a iceight. A weight acts with perfect uni-
formity, from the beginning to the end of its descent, pro-
vided the line, which suspends it, is of equal size through-
out, and that this line is w^ound upon a true and perfect
cylinder. In portable timekeepers, the weight, for ob-
vious reasons, cannot be employed ; and the springs al-
though a less perfect and equable power, is obliged to
be substituted. From the oldest clocks which remain, it
appears, that the spring was in use before the weight ; and
one of the first, ever made, is still preserved at Brussels,
in which the spring is an old sword-blade, from which a
piece of catgut is wound upon the cylinder of the first
wheel. The principal difficulty in the use of the spring
is, that its action is unequal, and that the more it is bent,
the greater force it exerts, to return to its natural situa-
tion. The spring of a watch, as it is now used, is a
long plate of steel, coiled up into a spiral form. From the
outside of this, proceeds a chain, which is attached, not to
a cylinder, as is done" willi ihc weight, but to a spiral
REGULATING MOVEMENT. PENDULUM. 191
roller, called a fusee, which, by its conical form, gives- to
the spring an increased mechanical advantage, in propor-
tion as its power diminishes. The fusee has already been
described, on page 62.
In some of the watches which are now made, the fusee
and the chain are dispensed with. The barrel, which
incloses the spring, has a toothed circle on its outside,
which turns round, as the spring unwinds, and gives mo-
tion t:> the machinery. But, in this case, the spring is
made larger than common, and only the middle part of
its action is used, it being never wound up so far, as to
call forth its greatest strength, nor suffered to run down,
so far as to be materially weakened.
Regulating Movement. — In the mechanism of clocks
and watches, it is necessary, so far to retard the move-
ment of the maintaining force, i. e., of the weight or
spring, that it may be hours and days in expending itself,
and that the timekeeper may require to be wound up, only
at distant and convenient periods. This is, in part, ef-
fected, by the successive combination of wheels and pin-
ions, the last of which turns round many hundred times,
while the first turns round once. But, if a timekeeper
possessed only wheels and pinions, it would run down,
with a rapidly accelerated motion, in the course of a few
seconds. It becomes, therefore, necessary, to connect
with it another motion, which cannot be accelerated, be-
yond a certain degree, by any given force. This mo
tion is obtained, in clocks, from the pendulum^ and, in
watches, from the balance ; and it is the one which it
was proposed to consider, as the second head, under the
name of the regulating movement.
Pendulum. — A pendulum is a weight, capable of vi-
brating about a point, from which it is suspended. If the
curve, in which the pendulum moves, be a circular arc,
it is necessary, that the length of the vibrations should be
exactly equal ; otherwise, the pendulum will not keep true
time. But, if the curve be a cycloidal one, the pendulum
will move, back and forward, in equal times, whatever be
the length of its vibrations. In practice, it is found diffi-
cult to make a pendulum move in a cycloidal path, with-
l92 ARTS OF HOROLOGY.
out too much friction. It is, therefore, customary, ni
clocks, to use pendulums, moving in circular arcs, these
arcs being made to approximate to cycloids, by being as
short as possible.
Pendulums, when set in mot'on, would continue to vi-
brate forever, were it not for the retarding effect of fric-
tion, and the resistance of the atmosphere. The former
of these is partly obviated, by hanging the pendulum upon
a thin spring, and the latter, by forming it with a sharp
edge. Still, a considerable force is requisite to sustain
the motion, and this force, in clocks, is derived from the
weight.
That pendulums may vibrate in equal periods, and thus
furnish a correct measure of time, it is necessary, that
they should always be of uniform length ; for pendulums
of different lengths differ in their vibrations, as the square
roots of their lengths. Now, such is the effect of heat,
in expanding all known substances, particularly metals,
that the same pendulum is always longer in summer than
it is in winter, and sufficiently so, to affect the correctness
of the timepiece, to which it is attached. To remedy this
difficulty, various ingenious contrivances have been resort-
ed to, the most common of which are, combinations of
metals, so connected, as to expand in opposite directions,
counterbalancing each other, so as to keep the centre oi
oscillation in one place. This is sometimes effected, in
the gridiron pendulum, by combining bars, or rods, of
steel and brass ; and, in the mercurial pendulum, by en-
closing a quantity of quicksilver, in a tube, near the bot-
tom of the pendulum.
Balance — As the pendulum depends upon the force of
gravity, for its motions, it obviously cannot be employed
for watches, or portable timekeepers, which are liable to
change their position. A substitute is found in the bal-
ance^ which is commonly a wheel, moving on an axis,
and which, when thrown, backward and forward, by oppo-
site appHcations of the moving force, performs its vibra-
tions in equal times. The balance is liable to the same
irregularities, from expansion and contraction, as the pen-
dulum, and is corrected in a similar manner ; and watches
SCAPEMENT. i93
go best, when they are kept in the uniform heat of the
body.
The quantity of matter, accumulated in the balance-
wheel of a common watch, is so extremely small, that it
seems impossible, that it should exert a perfect regula-
ting power. The want of weight, however, is, in some
measure, made up, by causing it to perform large vibra-
tions, and to move with great velocity. The rim of
the balance-wheel, in a good watch, frequently moves
through ten inches in every second. This velocity is
produced by the hair-spring, which throws the balance
back to the point of equilibrium, as fast as it is thrown
out, in either direction, by the moving force ; thus per-
forming for the balance, what gravity does for the pen-
dulum. If the hair-spring be taken away, a watch will
lose more than twelve hours in twenty-four, and go much
more irregularly. The operation of the common regula-
tor of a watch is, to tighten, or relax, this hair-spring, by
making its effective part longer or shorter, thus accelera-
ting, or retarding, the speed of the balance.
Scapement. — It remains to consider the third part, or
scapement, by which the rotary motion of the wheels is
converted into the reciprocating one of the pendulum and
balance. In the scapement, a certain part, connected
with the pendulum, or balance, is put in the way of the
last, or most rapid, wheel, so that only one tooth of this
wheel can escape by it, during each vibration. Thus, the
pendulum, or balance, while it receives its motion from
this wheel, becomes, in its turn, the regulator of its velo
city.
The crutch, or anchor-scapement, used in clocks,
and the common pailet-scapement with a contrate-wheel,
which is the kind most extensively used in watches, have
been already explained, under the head of Machinery,
page 72. The horizontal scapement. Fig. 183, con-
sists of a wheel, A, with elevated teeth, the outer surface
of which is curved obliquely. These teeth act upon the
edges of a hollow half cylinder, C, the axis of which is
parallel to that of the wheel, and carries the balance upon
one of its extremities. When a tooth of the scape-wheel
11= 17 xn.
194 ARTS OF HOROLOGY.
Fig. 183
Strikes the first edge of the cylinder, it causes it to re-
cede, moving the balance in one direction. The tooth
then enters the hollow part of the cylinder, and strikes
upon the opposite side. Before it can escape, the cylin
der is obliged to turn in the opposite direction, and thus
a vibrating movement is kept up, in the cylinder and bal-
ance.
A multitude of other scapements have also been in
troduced, by different artists, varying from each other, in
the complication of their structure, and accuracy of their
movements. But these must, necessarily, be omitted.
The operation of the simpler forms, already described,
will be more intelligible, taken in connexion with the
wheel-work, next to be noticed.
Description of a Clock. — In PI. IV. several views are
given of the mechanism of a clock, consisting of the go-
ing part^ which moves constantly, and carries the hands ;
and the striking part., which announces the hour. Fig.
1, PI. IV. is an elevation of the clock, with the wheels
seen edgewise, showing the going part ; the striking
movements being omitted, in this figure, to avoid confu-
sion. Fig. 2, is a front view of the wheel-work of both
going and striking parts ; and Fig. 3, is the dial-work., or
mechanism, immediately under the dial, or face of the
clock, and is that part which puts the striking train in mo-
tion, every hour. A clock of this kind contains two in-
dependent trains of wheel-work, each with its separate
first mover. One is constantly going, to indicate time, by
the hands on the dial-plate ; the other is put in motion,
once in an hour, and strikes a bell, to tell the hour at a
distance. The part, marked [a,] in Figs. 1 and 2, is
DESCRIPTION OF A CLOCK. 195
the barrel of the going part ; it has a catgut band, [6,]
wound round it, suspending the weight, which keeps the
clock in motion. The part, marked 96, is a wheel, call-
ed the first, or great "u'lieel, of ninety-six teeth upon the
end of a barrel, turning a pinion, 8, of eight leaves, on
an arbor,* which carries the minute-hand ; also, 64, is
a wheel of sixty-four teeth, on the same arbor, called the
centre-wheel, turning the wheel, 60, by a pinion of eight
leaves on its arbor. This last wheel gives motion to the
pinion of eight, on the arbor of the swing-wheel, 30,
which has thirty teeth. The parts [c?/i] are the pallets
of the scapement, fixed on an arbor, [e,] Fig. 1, going
through the back plate of the clock's frame, and carrying
a long lever, [/.] This lever has a small pin, projecting
from its lower end, going into an oblong hole, made in
the rod, B, of the pendulum.
The pendulum consists of an inflexible metalhc rod, sus
pended by a very slender piece of steel spring, D, from
a brass bar, E, screwed to the frame of the clock, having
a weight at its lower end, not seen in the figure ; in the
present case, thirty-nine and one eighth inches from the
suspension, D. When this pendulum is moved from the
perpendicular line, in either direction, and suffered to fall
back again, it swings nearly as much beyond the perpen-
dicular, on the contrary side, and then returns. This it
will continue to do, for some time ; and each of these vi-
brations will be performed in one second of time, when
the pendulum is of the above length. This is the meas-
urer of the time ; and the office of the clock is only to in-
dicate the number of vibrations it has made, and to give
it a small impulse, each time, to keep it going, as the re-
sistance of the air, and elasticity of the spring, D, would
otherwise, in a short time, cause it to stop. By the ac-
tion of the weight, appHed to the cord, [6,] which is called
the maintaining power, the wheels are all turned round ;
* The terms arbor, shaft, axle, and axis, are synonymously used by
mechanics, to express the bar, or rod, which passes through the centre
of a wheel. The terminations of a horizontal arbor are called gud-
geons, and of an upright one, frequently, pivots. The term axis, in
a more exact sense, may mean merely the longest central diameter, or
a diameter about which motion takes place.
I9b ARTS OF HOROLOGY.
and if the pallets [c? and h] were removed, the swing-
wheel, 30, would revolve, with great velocity, in the direc-
tion from 30 to [f/,] until the weight reached the ground.
The teeth of these pallets are so placed, that one of them
always engages the wheel, and prevents it from turning
more than half a tooth at a time. In the figure, the pallet
[d] has the nearest tooth of the w^heel resting on it, and
the pendulum is on the side [/i] of the perpendicular.
When it returns, it moves the pallet, [c/,] so as to allow the
tooth of the wheel to slip off; but, in the mean time, the
pallet [/i] has interposed its point, in the way of the tooth
next it, and stops the wheel, till the next vibration, or
second. The distance between the two pallets [d and
/i] is so adjusted, that only half a tooth of the wheel
escapes, at each vibration ; and, as the wheel has thirty
teeth, it will revolve once in sixty vibrations, of one second
each, or in one minute ; consequently, a hand, on the arbor
of this wheel, will indicate seconds, on the dial-plate, F,
which is a circle, divided into sixty. The pinion of eight,
on its arbor, is turned by a wheel of sixty, which, conse-
quently, will turn once in seven turns and a half of the
other, or in seven minutes and thirty seconds, or, in one
eighth of an hour. Its pinion of eight is moved by a wheel
of sixty-four, or eight times itself, which will turn in one
eighth part of the time. This will be an hour ; and, there-
fore, the arbor of this wheel carries the minute-hand of
the clock. The great wlieel of 96, being twelve times the
number of the pinion eight, will turn once in twelve hours,
and the barrel, [a,] with it. The cord of catgut goes
round sixteen times, so that the clock w^ill go eight days.
The hour-hand of the clock is turned by the wheel-
work, shown in Figs. 1 and 3. On the end of the arbor
of the centre wheel, 64, a tube is fitted, so as to go round
with it, by friction. This carries the minute-hand ; and,
if the clock should require correction, the hand may be
slipped round, without moving the wheels. This tube
has a pinion of forty teeth on its lower end, indicated by
a dotted circle. This turns another wheel, 40, of forty
teeth, which has a pinion of six teeth on its arbor, turning
a wheel, 72, of seventy-two teeth. The two wheels, 40,
STRIKING PART. 197
will both turn in an hour ; and 72, in twelve hours. The
arbor of this wheel has the hour-hand, and is a tube, going
over the arbor of the minute-hand, so that the two hands
are concentric. The barrel [a] is fitted to an arbor, com-
ing through the plate of the clock, and filed square, to put
on a key, to wind up the weight. The great wheel, 96,
is not fixed fast to the arbor, but has a click on it, which
takes the teeth of a ratchet-wheel, cut on the barrel ; so
that the barrel may be turned in one direction, to wind up
the weight, without the wheel ; but, by the descent of the
weight, the wheels will be turned with the barrel, by the
click.
Striking Part. — Having now considered the going part
of the clock, it remains to dfscribe the mechanism by
which the hour is struck. In Fig. 2, 78, is a great wheel
of seventy-eight teeth, provided with a barrel and chck,
as in 96 ; it turns a pinion of eight. On the same arbor
is a wheel, 64, turning a pinion of eight, on the arbor of
the wheel [o] of forty-eight. This turns another pinion
of eight, and w-heel [j)] of forty-eight, which turns a pin-
ion of six, on the sam.e arbor, with a thin vane of metal,
seen edgewise, which is called the fly, and which, by the
resistance of the air to its motion, regulates the velocity
of the wheels.
The wheel, 64, has eight pins projecting from it, which
raise the tail [n] of the hammer, as they revolve. The
hammer is returned, violently, when the pins leave its tail,
by a spring; [?7i,] pressing on the end of a pin, put through
ts arbor, and strikes the bell. The hammer and bell are
behind the plate, and, therefore, unseen. There is a short
spring, [/,] which the other end of the pin through the ar-
bor touches, just before the hammer strikes the bell. Its
use is, to lift the hammer off the bell, the instant it has
struck, that it may not stop the sound. The pins in the
wheel, 64, must pass by the hammer-tail seventy-eight
times, in striking the twelve hours, l-f2-t-3+4-f-5-|-6+
7+8+9+10+11+12=78 ; and, as its pinion has eight
leaves, each leaf of the pinion answers to a pin in the
wheel, 64. Now, as the great wheel has seventy-eight
teeth, it will turn once in twelve hours, the same as the
17*
108 ARTS OF HOROLOGY.
Other great wheel, 96. In the wheel, 64, eight of its teeth
correspond to one of the pins of the hammer, and, as the
pinion of the wheel [oj has eight teeth, it (wheel o) will turn
once, for each stroke of the hammer. By the remaining
wheels, one, [o,] multiplying six times, and the other, [p, ]
eight times, the fly will turn 6X8=48 times, for one turn
of [o,] which answers to one stroke of the hammer.
Fig. 3, is also mechanism, relating to the striking part.
Behind [r,] there is a small pinion, of one tooth, called the
gathering-pallet J on the arbor of the wheel, [o,] which,
consequently, turns once, for each stroke of the hammer.
The part, marked [Sra;,] is a portion of a large wheel,
and is called the rack. The part [t] is an arm attached
to the rack, whose end r«sts against a spiral plate, V,
called the snail, which is fixed on the tubular arbor, be-
fore described, of the hour-hand and wheel, 72, and turns
round with it once in twelve hours. The snail is divided
into twelve equal angles, of thirty degrees each, and, as
it turns, each of these answers to an hour. The circular
arcs, forming the circumference of the snail, are struck
from the centre of the arbor, between each division, with a
different radius,' decreasing a certain quantity, each time,
in the order of the hours. The circular part of the rack,
14, is cut intx) teeth, each of which is of such a length,
that every step upon the snail shall answer to one of them.
At [^0,] is a spring, pressing against the tail of the rack, and
acting to throw the arm of the rack against the snail. The
part Ig] is a click, called the hawk's-bill, taking into the
teeth of the rack, and holding it up, in opposition to the
spring, [io.~\ The part [ik'] is a three-armed detent,
called the warning-piece. The arm [/c] is bent at its
end, and passes through a hole, in the front plate of the
clock, so as to catch a pin, placed in one of the arms of
the wheel, [p,] Fig. 2, and which describes the dotted
circle, in Fig. 3. The other arm [i~\ stands, so as to
fall in the way of a pin, in the wheel, 40. In the pre-
sent position of the figure, the wheels of the striking train
are in motion, and would continue turning, until the gath-
ering-pallet at \r] which turns once, at each stroke of
the hammer, by its tooth lifts the rack, [s,] in opposition
STRIKING PART. 199
to ihe spring, [tc,] one tooth, each turn ; and the hawk's-
bill [g] retains the rack, until a pin, in the end of the
rack, is brought in the way of the lever of the gathering-
pallet, [r,] and stops the wheels from turning any further.
It is in this position, with the rack wound up, till its pin
arrests the tail, [r,] that we shall begin to describe the
operation of the striking of the clock.
The wheel, 40, as has been said before, turns'once in
an hour ; and, consequently, at the expiration of every
hour, the pin in it takes the end, [i,] and moves it to-
wards the spring near it. This depresses the end, [/c,]
until it falls in the circle of the motion of the pin, in the
wheel, [p,] Fig. 2. At the same time, the short tail de-
presses one end of the hawk's-bill, and raises the other,
[^,] so as to clear the teeth of the rack, [5.] Immedi-
diately, the spring [10] throws the rack back, until the
end of its tail [f] touches that part of the snail which is
nearest it. When the rack falls back, the pin in it is
mov^d clear of the gathering-pallet, [r,] and the wheels
are set at hberty. The maintaining power puts them in
motion ; but, in a very short time, before the hammer has
struck, the pin in the wheel [p] falls against the end of
[fc,] and stops the whole. This operation happens, a
few minutes before the clock strikes, and this noise of the
wheels turning is called the warning. When the hour is
expired, the wheel, 40, has turned so far, as to allow the
end of [i] to slip over its pin, as in the figure. The small
spring, pressing against it, raises the end, [/c,] so as to
be within the circle of the pin, in the wheel, [p,] Fig. 2.
Every obstacle is now removed, and the w^heels run on
the pinion ; the wheel, 64, raises the hammer, [r,] and
it strikes on the bell ; the gathering-pallet [r] takes up
the rack, one tooth at each turn, the hawk's-bill [g] re-
taining it, until the pin [x] in the rack, comes under the
gathering-pallet, [r,] and stops the motion of the whole
machine, till the pin in the wheel, 40, at the next hour,
takes the warning piece, [i/c,] and repeats the operation
we have now described. As the gathering-pallet turns
once, for each blow of the hammer, and its tooth gathers
up one tooth of the rack, at each turn, it is evident, that
200 ARTS OF HOROLOGY.
the number of teeth, which the rack is allowed to fall
back, hmits the number ot strokes the hammer will rauke.
This is done by the rack's tail, [f,] resting on the snail.
Each step of the snail answers to one tooth of the rack,
and one stroke of the hammer. At each hour, a fresh
step of the snail is turned to the tail of the rack, and, by
tliis means, the number of strokes is made to increase one,
at each time, from one to twelve.
Description of a Watch. — In PI. V., several views
are given of the construction of a common portable watch.
Fig. 1, represents the wheel-work, immediately beneath
the dial-plate, and also its hands, the circles of hours and
minutes being marked, though the dial, on which these are
engraved, is removed. Fig. 2, is a plan of the wheel-
work, all exhibited at one view, for which purpose, the
upper plate of the watch is removed. Fig. 3, is a plan
of the balance, and the work situated upon the upper plate.
Fig. 4, shows the great wheel, and the pottance-wheel,
detached. Fig. 5, the spring-barrel, chain, and fusee,
detached ; and Fig. 6, is an elevation of all the move-
ments together, the works being supposed to be opened
out into a straight line, to exhibit them all at once. Fig.
7, is a detached view of the balance, together with the
scapement, in action.
The principal frame, for supporting the acting parts of
the watch, consists of two circular plates, marked C and
D, in the figures. Of these, the former is called the
upper plate, and the latter, the pillar-plate, from the cir-
cumstance that the four pillars, EE, which unite the two
plates, and keep them a proper distance asunder, are fas-
tened firmly into the lower plate ; while the other ends
pass through holes, in the upper plate, C, and have small
pins put through the ends of the pillars, to keep the whole
together. By drawing out these pins, the watch may be
taken to pieces. The pivots of the several wheels being
received in small holes, made in these plates, they, of
course, fall to pieces, as soon as the plates are separated.
The maintaining power is a spiral steel spring, which
is coiled up close, by a tool used for the purpose, and put
into a brass box, called the barrel. It is marked A, in
DESCRIPTION OF A WATCH. 201
all the figures, and is shown separate, in Fig. 5, with the
spring in it. The spring has a hook, at the outer end of
its spiral, which is put through a hole, [a,] Fig. 5, in the
side of the barrel, and riveted fast to it. The inner end
of the spiral has an oblong opening, cut through it, to
receive a hook upon the barrel arbor, B, Fig. 5. The
pivots of this arbor pass through the top and bottom of
the barrel, and one of them is filed square, to hold a
ratchet-wheel, [6,] Figs. 1 and 6, which has a click, and
keeps the arbor from turning round, except in one direc-
tion. The two pivots of the arbor are received in pivot-
holes in the plates, CD, of the watch, and the pivot, which
has the ratchet-wheel upon it, passes through the plate.
The wheel marked [6,] Figs. 1 and 6, with its chck, is,
therefore, on the outside of the pillar-plate, D, of the
watch. The top of the barrel has a cover, or lid, fitted
into it, through which the upper pivot of the arbor pro-
jects ; thus, the arbor of the barrel is to be considered as
a fixture, the click of the ratchet-wheel preventing it from
turning round, while the interior end of the spiral spring,
being hooked, assists in rendering it stationary. The
barrel, thus mounted, has a small steel chain, [f/,] Figs.
2 and 6, coiled round its circumference, and attached to
it by a small hook of the chain, which enters a little hole,
made in the circumference of the barrel, at its upper end.
The other extremity of this chain is hooked to the lower
part of the fusee, marked F, Figs. 2, 5, and 6, and the
chain is disposed, either upon the circumference of the
barrel, or in the spiral groove, cut round the fusee for its
reception, the arbor of which has pivots at the ends, which
are received into pivot-holes, made in the plates of the
watch. One pivot is formed square, and projects through
the plate, to fit the key, by which the watch is wound up.
It is evident, that, when the fusee is turned by the
watch-key, it will wind the chain, off the circumference
of the barrel, on itself; and, as the outer end of the spring
is fastened to the barrel, and the other is hooked to the
barrel-arbor, which, as before mentioned, is prevented
from turning, by the click of the ratchet-wheel, [a^,] the
spring will be coiled up into a smaller compass than be-
202 AKTS OF HOROLCȴ.
fore. Its reaction, therefore, when the key is taken off,
will turn the barrel, and, by the chain, turn the fusee, and
give motion to the wheels of the watch. The fusee has
a spiral groov^e cut round it, in which the chain lies ; this
groove is cut by an engine, in such a form, that the chain
shall pull from the smallest part, or radius, of the fusee,
when the spring is quite wound up, and, therefore, acts
with its greatest force on the chain. From this point,
the groove gradually increases in diameter, so that, as the
spring unwinds, and acts with less power, the chain oper-
ates on a larger radius of the fusee ; and the effect, upon
the arbor of the fusee, or the toothed wheel attached to
it, will always be equal, and cause the watch to go with
regularity.
To prevent too much chain being wound upon the fu
see, and, by that means, breaking the chain, or over-
straining the spring, a contrivance, called a guard-gut^ is
added. It is a small lever, [e,] Fig. 2, moving on a
stud, fixed to the upper plate, C, of the watch, and press-
ed downwards by a small spring, [/.] As the chain is
wound up, upon the fusee, it rises in the spiral groove, and
lifts up the lever, until it touches the upper plate. It is
then in a position to intercept the edge, or tooth, [^,] of
the spiral piece of metal, seen on the top of the fusee, and
thus stops it from being wound up any further.
The power of the spring is transmitted to the balance,
by means of several toothed wheels, which multiply the
number of revolutions, which the chain makes on the fu-
see, to such a number, that, though the last, or balance-
wheel, turns nine and one half times every minute, the fu-
see will, at the same time, turn so slowly, that the chain
will not be drawn off from it, in less than, twenty-eight or
thirty hours, and it will make only one turn, in four hours
This assemblage of wheels is called the train of the
watch. The first toothed wheel, G, is attached to the
fusee, and is called the great wheel. It is shown separa-
ted from the fusee, in Fig. 4, having a hole through the
centre, to receive the arbor of the fusee, and a projecting
ring upon its surface. The under surface of the base of
the fusee is shown in Fig. 5, at F, having a circular
DESCRIPTION OF A WATCH. 203
cavjiy cut in it, to receive the corr^|ponding ring upon
the great wheel, G, Fig. 4. A ratchet-wheel [i] is
fixed fast upon the fusee arbor, and sunk within the cav-
ity, excavated in the lower surface of the fusee. When
the wheel and fusee are put together, a small chck, [/i,]
Fig. 4, takes into the teeth of the ratchet, [i.] As the
/iisee is turned by the watch-key, to wind up the watch,
tl.s click slips over the sloping slides of the teeth, with-
out turning the great wheel ; but, when the fusee is turned
the other way, by drawing the chain from the spring-bar-
rel, the click catches the teeth of the ratchet-wheel, and
causes the toothed wheel to turn with the fusee.
The great wheel ^ G, has forty-eight teeth on its cir-
cumference, which take into, and turn, a pinion of twelve
teeth, fixed on the same arbor with the
Centre-wheel^ H, so called, from its 5atuation in the
centre of the watch ; it has fifty-four teeth, to turn a pin-
ion of six leaves, on the arbor of the
Third wheel, I, which has forty-eight teeth. It is sunk
ni a cavity, formed in the pillar-plate, and turns a pinion
of six, on the arbor of the
Contrate-wheel, K, which has forty-eight teeth, cut
parallel with its axis, by which it turns a pinion of six
leaves, fixed to
The halance-wheel, L. One of the pivots of the arbor
of this wheel turns in a frame, M, called the pottance, or
potence, fixed to the upper plate, and shown separately, in
Fig. 4. The other pivot runs in a small piece, fixed to
the upper part, called the counter potlance, not shown in
any of the figures ; so that, when the two plates are put
together, the balance-wheel pinion may work into the
teeth of the contrate- wheel, as shown in Fig. 6. The
balance-wheel, L, has fifteen teeth, by which it impels
the balance, [op.] The arbor of the balance, which is
called the verge, has two small leaves, or pallets, projec-
ting from it, nearly at right angles to each other. These
are acted upon by the teeth of the balance-wheel, L, in
such a manner, that, at every vibration, the balance re-
ceives a slight impulse to continue its motion ; and every
vibration, so made, suffers a tooth of the wheel to escape,
204 ARTS OF HOROLOGY.
or pass by ; whMpjB this part is called the scapement oi
the watch, and constitutes its most essential part. The
wheel, L, is sometimes called the scape-wheel^ or crown-
wheel. Its action is explained by Fig. 7, which shows
the wheel, and balance, detached. Suppose, in this view,
the pinion [h] on the arbor of the balance-wheel, or
crown-wheel, [i/c,] to be actuated by the main-spring,
which forms the maintaining- power, by means of the train
of wheel-work, in the direction of the arrow, while the
pallets, [m and n,] attached to the axis of the balance,
and standing at right angles to each other, or very nearly
so, are long enough to fall in the way of the ends of the
sloped teeth of the wheel, when turned round, at an angle
of forty-five degrees, so as to point to opposite directions,
as in the figure. Then a tooth in the wheel below, for
instance, meets with the pallet, [n,] supposed to be at
rest, and drives it before it, a certain space, till the end
of the tooth escapes. In the meantime, the balance,
[ospr,'] attached to the axis of the pallets, continues to
move in the direction [rosp,] and winds up the small
spiral, or hair-spring, [9,] one end of which is fast to
the axis, and the other to a stud, on the upper plate of
the frame. In this operation, the spring opposes the mo-
mentum, given to the balance, by this push of the tooth
upon the pallet, and prevents the balance going quite
round ; but, the instant the tooth escapes, the upper pal-
let [m] meets with another tooth, at the opposite side
of the wheel's diameter, moving in an opposite direction
to that below. Here, this pallet receives a push, which
carries the balance back again, its momentum, as yet,
being small in the direction [ospr,'] and aids the spring,
which now unbends itself, till it comes to its quiescent
position, then swings beyond that point, partly, by the im-
pulse from the maintaining powder on the pallet, [m,] and
partly, by the acquired momentum of the moving balance,
particularly when this pallet [m] has escaped. At length,
the pallet [w] again meets with the succeeding tooth, and
is carried backward by it, in the direction in which the
balance is now moving, till the maintaining power and
force of the unwound spring, together, overcome the mo-
DESCRIPTION OF A WATCH? 205
mentum of the balance, during which time, the recoil of
the balance-wheel is apparent, and, also, of the second-
hand, if the watch has one, its place being on the arbor
of the contrate-wheel. Then the wheel brings the pallet
[n] back again, till it escapes ; and the same process takes
place w^ith the pallet, [??i,] as has been described with re-
spect to pallet, [n.] Thus, two contrary excursions, or
oscillations, of the balance take place, before one tooth
has completely escaped ; and, for this reason, there must
always be an odd number of teeth in this wheel, that a
space on one side of the wheel may always be opposite
to a tooth on the other, in order that one pallet may be
out of action, while the other is in action.
The upper pivot of the verge is supported in a cover,
screwed to the upper plate, as shown at N, in Fig. 6,
which extends over the balance, and protects it from vio-
lence. The lower pivot works in the bottom of the pot-
tance, M, at [?,] Fig. 4. The socket, for the pivot of
the balance-wheel, is made in a small piece of brass, [v,]
which slides in a groove, made in the pottance, as shown
in Fig. 4 ; so that, by drawing the slide in or out, the
teeth of the balance-w^heel shall just clear one pallet, be-
fore it takes the other ; and, upon the perfection of this
adjustment, which is called the scaping of the watch, the
performance of it very greatly depends.
It now remains to show the communication of this mo-
tion to the hands of the watch, which indicate the time
on the dial-plate. The hands are moved by the central
arbor, which comes through the pillar-plate, and projects
a considerable length. It has a pinion of twelve leaves,
called
The common pinion, \_w,] Fig. 6, fitted upon it, the
axis of which is a tube, formed square at the end, to fix
on the minute-hand, W. It fits tight upon the projecting
arbor of the centre-wheel ; and, therefore, turns with it,
but will slip round to set the hands, wlien the watch is
wrong, and requires to be rectified. The common pin-
ion is situated close to the pillar-plate, and its leaves en-
gage the teeth of
The minute-wheel, X, Figs. 1 and 6, of forty-eight
II. 18 XII.
206 ARTS OF HOROLOGY.
teeth, \^hich is fitted on a pin fixed in the plate, and Its
pinion, [x,] of sixteen leaves, which is fixed to it, turns
The hour-icheel, Y, of forty-eight teeth. The arboi
of this is a tube, which is put over the tube of the cannon-
pinion^ carrying the minute-hand, and has the hour-hand,
Z, fixed on it, to indicate the time upon the dial-plate.
Thus, by the cannon-pinion, [lo,] which is to the minute-
wheel, X, as one is to four, and the pinion [x] of this,
which is to the hour-wheel, Y, as one is to three, the hour-
wheel, Y, and its hand, [2:,] though concentric with the
cannon-pinion and minute-hand, make but one revolution,
during twelve revolutions of the other ; therefore, one
turns round in an hour, and the other turns round once in
twelve hours, as the figures on the dial show.
It is necessary to have some regulation^ by which the
rate of the watch's movement may be adjusted ; for, hith-
erto, we have only spoken of making the watch keep al-
ways to a uniform, or certain rate of, motion ; but it is
necessary to make it keep true time. This can be done
by two means ; either by increasing or diminishing the
force of the main-spring, which increases or diminishes
die arc which the balance describes ; or it may be done,
by strengthening or weakening the hair-spring, which will
cause the balance to move quicker or slower.
The hair-spring, otherwise called the pendulum- springs
[</,] Fig. 3, is fixed to a stud, upon the plate, [c,] by
one end, and is attached to the verge of the balance, by
the other.
The regulation is effected by means of what is called
the curb. This is a small lever, [r,] Fig. 3, projecting
frorr. a circular ring, [rr,'] which may be considered as
its centre of motion, but perforated with a hole through
the centre, large enough to contain the hair-spring within
it. A circular groove is turned out in the upper plate,
nearly concentric with the balance, and the ring [rr]
fits into this. Both are turned rather largest at the bot-
tom, in the manner of a dove-tail ; but the ring, being
divided at the side, opposite to the lever, [r,] can be
sprung up, and rendered so much smaller, as to get it
into the groove ; and, being once in, the elasticity of the
DESCRIPTION OF A WATCH. 207
ring expands it, so as to fill the groove completely. In
this state, it may be considered as a lever, which describes
a circuit romid the verge, as a centre ; and the end of it
points to a divided arc, engraved on the upper plate, one
end of which is marked F, and the other, S, denoting that
the index, or lever, [r,] is to be moved towards one or
the other, to make the watch move faster or slower, as
its regulation requires.
The manner of its operation is thus ; the end of the
lever, or index, [2:,] continues within the circle, a small
distance towards its centre, and, passing beneath the outer
turn of the spiral spring, [^,] has two very small pins
rising up from it, which include the spring between them.
The actual length of the hair-spring is, therefore, to be
estimated from these pins, to the place of its connexion
with the verge. Now, by altering the position of the in-
dex, this acting length can be regulated, at pleasure, to
produce such vibration of the balance, as will make the
watch keep true time. By shortening the length, the
spring becomes more powerful, and returns the balance
quicker, so that it will vibrate in less time. This is effec-
ted by moving the index towards F. On the other hand,
turning the index towards S, lengthens the spring, by
which it becomes more delicate, and less powerful, re-
turning the balance slower than before.
Many watches, instead of the arc and index, have a
circular curb, or regulator, which is turned by a central
arbor, to which the watch-key is applied, when it is ne-
cessary to move it.
Delicate watches have jewelled pivot-holes, for the top
and bottom of the verge, to diminish the friction. These
jewels are diamonds, rubies, and other stones, which unite
great hardness with durabihty. Each consists of two
pieces, one of which has a cylindrical hole drilled through
it, to receive the pivot, the other is a flat piece, making
the rest, or stop, which forms the bottom of the hole
Both stones are ground circular on the edge, and are fit-
ted and burnished into small brass rings, which are fast-
ened into the bearings, above and below, by two small
screws, applied to each. The addition of jewels to a
208 ART OF METALLURGY.
watch is a great advantage, as they do not tendto thicken
the oil, which brass is apt to do, in consequence of the
oxidation of the metal.
Mr. Dent, a lecturer before the Royal Institution, ex-
hibited to his audience, a dissected watch, showieg the
complicated nature of this little machine. It appears, that
the number of pieces, in a complete lever watch, is nine
hundred and ninety-two, and the number of separate trades,
employed in manufacturing these pieces, and in putting
them together, is forty-three.
Works of Referek-ce. — Cummings's Elements of Clock and
Watch Work, 4to. 1766 ; — Berthoud, Historie de la Mesure du
Temps par les Horloges, 2 torn. 4to. 1802 ; — Harrison, on Clock
Work and Music, 8vo. 1775 ; — Robison's Mechanical Philosophy,
article Watch Work,\o\. iv. ; — Martin's Circle of Mechanical Arts,
4to. 1818 ; — and the Encyclopedias of Brewster, Rees, and Nich-
olson, under various heads.
CHAPTER XX.
ARTS OF METALLURGY.
Extraction of Metals, Assaying, Alloys. Gold, Extraction, C^ipeha
tion. Parting, Cementation, Alloy, Working, Gold Beating, Gilding
on Metals, Gold Wire. Silver, Extraction, Working, Coining, Plat-
ing. Copper, Extraction, Working. 2?rass, Manufacture, Buttons,
Pins, Bronze. Lead, Extraction, Manufacture, Sheet Lead, Lead
Pipes, Leaden Shot. Ti?i, Block Tin, Tin Plates, Silvering of Mir-
rors. Iroii, Smelting, Crude Iron, Casting, ^Malleable Iron, Forg-
ing, Rolling and Slitting, Wire Drawing, Nail Making, Gun Ma'-ing.
Steel, Alloys of Steel, Case Hardening, Tempering, Cutlery.
The term metallurgy, in its most comprehensive sen«e,
signifies the art of working metals, in every different way.
In a more precise and limited sense, it is confined to the
separating of metals from their ores, and assaying them,
to ascertain their value. In the present chapter, it is pro-
posed to make use of the term in its more general mean-
ing ; so far, at least, as to comprehend certain processe*^
EXTRACTION OP METALS. 209
in the management and manufacture of metals, which are
sufficiently interesting, to merit the attention of the general
student.
Extraction of Metals. — Metals are found in Nature, m
various states. When uncombined, or when combined
only with each other, they are said to be in a native state.
When combined with other substances, so that the me-
tallic properties are., in some measure, disguised, they
are said to be mineralized, or in the state of ore. The
substance, with which the metal is combined, is termed
its mineralizer. The most common states of combina-
tion, in which the metallic ores are found, are oxides,
combinations of oxides with carbonic, sulphuric, muriatic,
and phosphoric, acids and sulphurets. These ores oc-
cur, under various forms, sometimes crystallized, and often
destitute of any regular figure. They are met with, gen-
erally, in veins, penetrating the strata ; and, in this case,
are usually blended, or intermixed, with various earthy
fossils, as calcareous spar, fluor spar, quartz, &c. The
accompanying fossil is termed the gangue^ or matrix, of
the metal. Some metallic ores occur in beds, or in large
insulated masses.
To separate the metal, after it is dug from the mine,
the mass is broken up, and subjected to the operations
of sorting, stamping, washing, roasting, smelting, and re-
fining. Sorting consists merely in the separation of the
different pieces of ore, into lots, according to the products
they are expected to afford, and the treatment they are
likely to require. After the ore is sorted, it is carried to
the stamper, or stamping-mill, which has been described
in a former chapter. The process of stamping, breaks
and pounds up the ore, together with its gangue, into a
coarse powder. From the stamping-mill, the pounded
ore is conveyed to the icashing ; a process, in which ad-
vantage is taken of the difference of specific gravity. The
operation of w^ashing is sometimes performed by hand, in
wooden vessels, or in troughs, which cross a current of
water ; and, sometimes, if the ore is rich, and valuable,
upon inclined tables, covered with cloth. In this pro-
cess, the heavier parts, consisting of the metaUic ore,
18*
210 ARTS OF METALLURGY
sink first to the bottom, while the stony matter, which is
lighter than the ore, being longer in sinking, is carried
further down the current, and thus separated from the rest.
The next operation, which is that of roasting^ is em-
ployed to drive off the sulphur, arsenic, and other volatile
parts, which the mineral may contain. It is performed
in a variety of ways, and by different processes, accor-
ding to the nature of. the ore, and the degree of heat re-
quired. The roasting is sometime performed in the air,
and sometimes, in furnaces, among the fuel. Smelting
consists, in general, in fusing the roasted ore, with a view
to extract the metal ; though the term is sometimes ap-
plied to the melting of metal, in any state, especially iron
The immediate object of this process is to reduce the
metal, or to separate the oxygen, with which the metal
has either been naturally combined, or has united, during
the operation of roasting. This is done, by placing in a
furnace, alternate layers of charcoal, or coke, and of the
metallic matter ; a strong heat is then excited by bellows ;
the carbonaceous matter attracts the oxygen, while the
metal is reduced, melted, and run out, at the bottom of
the furnace. The volatile metals are obtained by subli-
mation, or distillation. Even after these operations, the
metal is seldom pure, but is combined with some other
metal or metals, which have been present in the ore. If
these are in small quantity, and do not injure the metal,
they are in general disregarded. If it is necessary, how-
ever, to separate them, or if, from their value, the sep-
aration is an object of importance, different processes are
followed, adapted to each particular metal. All the op-
erations, subsequent to smelting, are comprehended under
the general name of refining^ because their effect is always
to obtain a purer metal. The difierent metals are refined
by different processes.
Assaying. — The art of assaying metallic ores is that
of analyzing them, in small quantities, so as to discover
their component parts. It requires a knowledge of the
relations of the metals to the other chemical agents, and
is varied, in its different stages, as applied to each. The
general process consists, in selecting proper specimens of
ALLOYS. 211
the ore, which is done, by taking equal portions of that
which appears to be the richest, the poorest, and of me-
dium value, and reducing these to coarse powder, w^hich
is washed, to carry off any earthy or stony matter. It
is then roasted in a shallow earthen vessel, under a muffle,
to expel the volatile principles. It is lastly reduced, by
mixing it with fluxes, and applying a more or less intense
heat, as the metal is more or less refractory. The me-
tallic matter, existing in the ore, is thus obtained. This,
it is obvious, may consist of various metals ; and, if there
is reason to beheve this, 'and it be of importance to ascer-
tain it, it is submitted to operations, adapted to the metals
which may be supposed present. Sometimes, an accu-
rate analysis is made, at once, of the metalhc ore, in the
humid way ; the metal being dissolved by the different
acids, and precipitated by the alkalis, earths, and other
re-agents. The assaying of the precious metals is usual-
ly confined to ascertaining the quantity of gold or silver,
in any alloy or compound, without regard to the other
constituents.
Alloys.-^The metals are capable of combining with
each other, by fusion ; and to these combinations, the name
of alloy is given. They all retain the general metalhc
properties, — lustre, opacity, and density ; and even, in the
greater number of cases, the properties of the constituent
metals remain in the combination, only somewhat modi-
fied. In general, alloys are more hard and brittle than
the individual metals of which they consist, though this,
as well as the other changes of properties, is considerably
influenced by the proportions, in which the. ingredients are
combined. They have also, in general, a greater fusi-
bility, than the mean fusibihty of the respective metals.
The alloys of quicksilver, called amalgams^ are usually
soft, or liquid, according to the proportions. The metals
combined in alloys, are generally more susceptible of ox-
idizeraent, than in their separate state ; owing, probably,
to the diminution in the power of cohesion, by the com-
bination, or, perhaps, to an electrical action. From their
peculiar properties, some of the alloys are extensively
used, as brass, which is an alloy of copper and zinc ; and
Dewter, which is an alloy of tin and zinc or lead.
212 ARTS OF METALLURGY.
A degree of condensation usually attends these combi-
nations, so that the specific gravity of the alloy is greater,
than the mean specific gravity of its constituent metals.
In brass, for example, it is one tenth greater, and, in
some cases, the condensation is such, that the density is
even greater than that of the heavier metals combined, as
in the alloy of silver and quicksilver. Sometimes, how-
ever, the particles assume such an arrangement, that the
density is less than the mean, as in the examples of the
alloy of copper with silver, and of gold with tin, and gold
with iron.
In these combinations, there exists a certain order of
attractions, by which one metal is more disposed to unite
with another, than a third is. The difference, however, is
not very considerable ; hence, three, four, or more, metals
can be combined together. Some, however, are difficult
to unite, as iron and lead, and iron and quicksilver. The
combination seems to be, in some measure, regulated by
the relations of fusibility and specific gravity ; so that, the
affinities being equal, the metals are less disposed to com-
bine, as they differ more in their fusibihty and specific
gravity ; and, where the affinity is weak, a considerable
difference of this kind may prevent any combination what-
ever.
GOLD.
Gold exists in various minerals ; but the greatest part
of the gold, in the possession of mankind, has been found
in the form of grains and small masses, among the alluvial
sands, which constitute certain plains, and margins of riv-
ers. In this state, it is usually alloyed with small por-
tions of other metals, particularly silver and copper.
Extraction. — When native gold is found in a state of
m'lxture with foreign matters, its extraction is commonly
performed by amalgamation with quicksilver. After hav-
ing been freed, by pounding and washing, from most of the
stony matter mixed with it, it is triturated with ten times
its weight of quicksilver, until an amalgam is formed.
This is separated from any superfluous earthy matter, and
subjected to pressure, enclosed in leather, by which the
CUPELLATION. PARTING. 213
more fluid part is separated, and forced through the leath-
er, while the more consistent amalgam, containing the
greater part of the gold, remains. It is then subjected to
distillation, in retorts of earthen ware, to separate the
quicksilver, and the remaining gold is afterwards fused.
When the gold is contained in other ores, the ore is
roasted, to drive off the more volatile principles, and to
oxidize the other metals. The gold is then extracted, by
amalgamation, by liquefaction with lead, by the action of
nitric acid, or other methods, adapted to each ore, accor-
ding to its constituent parts.
Cupellation. — Gold, obtained in any of these ways, is
always more or less alloyed, particularly with silver or
copper. The first step in its purification is the process
of cupellation. To explain the nature of this, it is neces-
sary to observe, that lead is a metal very fusible, and ex-
tremely easy of oxidizement, forming an oxide, which easi-
ly vitrifies, and which favors the oxidizement and vitrifica-
tion of other metals. A portion of lead, therefore, is ad-
ded to the impure gold, more or less, according to the
quantity of alloy which it contains, of which the work-
man judges by the color, hardness, elasticity, and specific
gravity, of the gold. They are melted together, and ex-
posed to heat on a cupel, which is a vessel made of bone-
ashes, or, sometimes, of wood-ashes, under a muffle, or,
in the large way, on the hearth of a refining furnace.
The lead passes to the state of oxide, is vitrified, and, at
the same time, promotes the oxidizement and vitrification
of the foreign metals. The vitrified oxide is absorbed
by the porous cupel, or, in the large way, the greater
part is driven off by the blast of bellows, and removed.
When the greater part of the foreign metals is abstracted,
the remaining fused metal exhibits various prismatic col-
ors, which succeed each other quickly. It at length sud-
denly brightens, and its surface becomes highly luminous.
This IS regarded as the completion of the process. The
metal is allowed to become solid, and, while yet hot, is
detached.
Parting. — The gold, even after having been submitted
to this process, may still be alloyed with silver, which,
214 ARTS OF METALLURGY.
being nearly as difficult of oxidizement, is not removed
by the action of the lead. It is, therefore, lastly sub-
jected to the operation of parting. The metal is rolled
out thin, and cut into small pieces. These are digested
with a moderate heat, in diluted nitric acid, which dis-
solves the silver, leaving the gold, undissolved, in a por-
ous mass. It has been found, however, that, when the
proportion of silver is small to that of gold, the latter
protects the former from the action of the acid The
previous step of quartation, as it is named, is therefore
employed, which consists in fusing three parts of silver
with one of the gold, and then subjecting this alloyed
metal, rolled out, to the operation of the acid. These
are the operations employed in commerce. To obtain
gold, perfectly pure, still another process is, perhaps, nec-
essary,— dissolving it in nitro-muriatic acid, and adding
to the solution, a solution of sulphate of iron, which, at-
tracting the oxygen, precipitates the gold, in the metallic
state.
Cementation. — The process of cementation is per
formed, by beating the alloy into thin plates, and placing
these in alternate layers, with a cement, containing nitrate
of potass, and sulphate of iron. The whole is then ex-
posed to heat, until a great part of the alloying metals
are removed, by the action of the nitric acid, which is
liberated by the nitre. Cementation is sometimes em-
ployed, by goldsmiths, to refine the surface o^ articles, in
which gold is alloyed with baser metals.
Alloy. — There is a peculiar language, established in
commerce, and often referred to, by WTiters, to denote
the purity of gold, or the degree of its alloy with other
metals. The mass is supposed to consist of twenty-four
equal parts, these imaginary parts being termed carats.
If perfectly pure, or unalloyed, it is said to be gold twen-
ty-four carats fine ; if alloyed with one part of any other
metal, or mixture of metals, it is said to be twenty-three
caiats fine. In this way, the proportion of alloy is ex-
pressed. The standard gold coin of the United States,
and Great Britain, is twenty- two carats fine ; or contains
one twelfth part of alloy.
WORKING. GOLD-BEATING. 215
Gold, when perfectly pure, is not so fit for coin, on
account of its softness, in consequence of which, the im-
pression is soon obliterated, and it sustains loss from fric-
tion. Hence, it is always alloyed, to give it hardness.
The metals, that have been used for this purpose, are sil-
ver or copper. Gold, made standard by an alloy, con-
sisting of equal parts of silver and copper, has a color,
approaching more to that of pure gold, than any other
alloy. This color also remains uniform, while that with
copper, after a certain degree of wear, becomes une-
qual.* •
Working. — Common goldsmiths' work is performed,
by casting in moulds, beating with hammers, and rolling
between polished steel rollers. Works, that have raised
or embossed figures, are commonly cast in moulds, and
afterwards polished ; or, they are struck in dies, cut for
the purpose. Vessels, both of gold and silver, are beat
out from flat plates. When the form is difficult, they
are made of several plates, and soldered together. The
solder used for this purpose, is an alloy of gold with si.
v^er, copper, or brass. Small ornamental works are
commonly executed, by enchasing. This process is per-
formed upon thin plates of gold, W'ith a block and ham-
mer. It consists, in driving in portions of the metal, on
one side, in such a manner, that they stand in relief, form-
ing the figures required, on the opposite side. Many
small articles are also made from gold wire, variously
ft^rought and ornamented.
Gold Beating. — The great utility of gilding, in the
urts, in furnishing an incorruptible covering to various
* Mr. Hatchet, with Mr. Cavendish, subjected the different alloys
ihat have been used as coin, to friction, as similar as possible to that
to which they must be subjected, in the course of circulation. The
loss was by no means considerable ; and it appeared, as the general
result, that the present standard of gold, or an alloy of one part in
twelve, is, all circumstances considered, the best, or at least, as good
as any, that could be chosen. If the copper be in larger proportions,
more loss is sustained, from friction. The same alloy is employed in
the fabrication of plate, and of trinkets, and lace, and, by other addi-
tions, various shades of color are obtained. Its alloy with a fifth of
silver forms the green gold of the jewellers^ and the addition of iron
gives a blue tint.
216 ARTS OF METALLURGY.
substances, has given rise to an extensive consumption of
qold-leaf^ which is formed, by beating the metal to a
state of extreme tenuity. The gold is first forged into
plates, on an anvil, and then reduced, by passing it be-
tween polished steel rollers, till it becomes a riband, as
thin as paper. This riband is divided into small pieces,
which are again beat upon an anvil, till they are about an
inch square, after which, they are thoroughly annealed.*
Two ounces of gold make one hundred and fifty of these
squares. All these squares are interlaid with leaves, first
of vellum, and afterwards, of gold-beater's sfcin, a thin
membraneous substance obtained from the intestines of
animals. The whole is then beaten with a heavy ham-
mer, till the gold is extended to the same size as the
pieces of skin. The gold leaves are then taken out, and
each cut into four parts ; and the six hundred pieces,
thus produced, are again interlaid, in the same manner,
with skins, and the beating repeated, with a hghter ham-
mer. They are afterwards. re-divided, as before, and
formed into parcels, which are separately beat, at one
or more operations, until the leaf has attained the requi-
site thinness. The use of the membranes, which are in-
terposed between the leaves, is, to prevent them from co-
hering together, at the same time that they are permitted
to expand ; and, also, to soften the blows of the hammer.
Notwithstanding the vast extent, to which gold is beaten
between these skins, and the great tenuity of the skins
themselves, yet they are said to sustain continual repeti-
tions of the process, for a long time, without receiving inju-
ry. The kind of leaf, called party-gold, is formed, by lay-
mg a thin leaf of gold upon a thicker one of silver. They
are then heated, and pressed together, till they unite and
cohere ; after which, they are beaten into leaves, as before.
Gilding on Metals. — Gilding on cc^per is commonly
performed with an amalgam of gold and mercury. The
surface of the copper, being freed from oxide, is covered
* The process of annealing is applied to metals, and some other
substances, to diminish their brittleness, or increase their flexibility
and ductility. It is performed, by heating the substance, and suffering
it to cool, in a very gradual n)anner.
GOLD-WIRE. SILVER EXTRACTION. 217
with the amalgam, and afterwards exposed to heat, till the
mercury is driven off, leaving a thin coat of gold. It is
also performed, by dipping a linen rag in a saturated solu-
tion of gold, and burning it to tinder. The black pow-
der, thus obtained, is rubbed on the metal to be gilded,
with a cork dipped in salt water, till the gilding appears.
Iron or steel is gilded, by applying gold-leaf to the met-
al, after the surface has been well cleaned, and heated,
until it has acquired the blue color, which, at a certain
temperature, it assumes. The surface is previously bur-
nished, and the process is repeated, when the gilding is
required to be more durable. It is also performed, by di-
luting the solution of gold in nitro-muriatic acid, with al-
cohol, and applying it to the clean surface.*
Gold Wire. — The common gold or gilt wire is, in
reahty, silver wire covered with gold. In making it, a
silver rod is enclosed in thick leaves of gold. It is then
drawn, successively, through conical holes, of different
sizes, made in plates of steel, in a manner similar to that
pursued in making iron wire. The wire may thus be re-
duced to an extreme degree of fineness, the gold being
drawn out with the silver, and constituting a perfect
coating to the wnre. When it is intended to be used In
forming gold-thread, the wire Is flattened, by passing it
between rollers of polished steel. The coating of gold
remains unbroken, though so far reduced, by these pro-
cesses, as not to occupy the millionth part of an inch in
thickness. The gold-thread, commonly used in embroi-
dery, consists of threads of yellow silk, covered by flat-
tened gilt wire, closely wound upon them by machinery.
SILVER.
Extraction. — Silver is, in general, extracted without
* This last process has been improved by Mr. Stoddart. A satura-
ted solution of gold in nitro-muriatic acid, being mixed with three times
its weight of sulphuric ether, dissolves the muriate of gold, and the
solution is separated from the acid beneath. To gild the steel, it is
merely necessary to dip it, the surface being previously well polished
and cleaned, in the etherial solution, for an instant ; and, on with-
drawing it, to wash it instantly, by agitation in water. By this method,
steel instruments are very commonly gilt.
II. 19 XII.
218 ARTS OF METALLURCr.
much difficulty. When native, it is separated from the
eartliy matter, by washing, and amalgamation with mer-
cury ; the latter being separated again, by distillation.
When alloyed with antimony, or arsenic, or when mineral-
ized, the ore is roasted, to expel these metals, with the
sulphur, or other volatile principles ; and the residual mat-
ter is fused with lead, and refined by cupellation, in a
manner similar to that described under the head of gold ;
the alloy of lead and silver being exposed to heat, on the
hearth of the refining furnace, the lead being oxidized
along with the foreign metals, the oxidizement and vitrifi-
cation of which it promotes, and the vitrified oxide being,
in part, absorbed, and, in part, driven off by the blast of
the bellows. The appearance of a vivid incandescence,
or brightening, denotes when the silver has become suffi-
ciently pure. It retains a little gold in combination, but
this does not alter its quahties ; and the quantity is seldom
such, as to render its separation, by the operation of
parting, an object of importance.
If the ore which is wrought contain only a small por-
tion of silver, the previous operation of eliquation is
sometimes performed on it. This consists in adding a
certain portion of lead to the metalhc matter which re-
mains, after roasting, and fusing the ore. This alloy is
then exposed to a degree of heat, just sufficient to melt
the lead, which runs out, and, from its affinity to the sil-
ver, carries it along with it, leaving the copper, or other
metals, with which the silver had been combined. The
alloy of silver and lead is then subjected to the usual re-
fining process.
Working. — Silver is cast into bars, or ingots, and af
ter wards wrought, by hammering and rolling. The bars
are beaten upon anvils, being heated, from time to time,
to render them more ductile. The hammering is con-
ducted, while the heat is below redness. They are then
passed between polished steel rollers, until they are re-
duced to plates of a suitable thickness. To form uten-
sils of different kinds,- these plates are hammered in
moulds, till they acquire the proper shape. Vessels are
often made in pieces, which ar© afterwards united by sol
COINING. 219
derlng. The solder, used for silver, consists of an alloy
of silver, with more than an equal part of copper or brass.
Figures, which are raised upon the silver, are produced
by hammering the metal upon steel dies, in which the
figure is cut, or by passing it through engraved rollers.
Silver is polished, by burnishing it with steel instruments,
or with hard polished stones ; and by rubbing it with the
oxide of iron, called colcothar^ in fine powder.
Silver, in the arts, is usually alloyed with a little cop
per, which increases its hardness, and renders it more
sonorous, without debasing its color. The standard sil-
ver of the British coins contains eighteen pennyweights
of copper, in a pound Troy of silver ; and, in the Uni-
ted States, sixteen hundred and sixty-four grains of silver
contain one hundred and seventy-nine grains of copper.
Coining. — The coining of silver, and other metals,
was originally performed by the hammer, in matrices, or
dies, engraved for the purpose. At the present day,
coins, of every description, are more commonly milled.
In coining by the mill, the bars or ingots, of gold or sil-
ver, after having been cast, are taken out of the moulds,
and their surfaces cleaned. They are then flattened by
rollers, and reduced to the proper thickness, to suit the
species of money, about to be coined. To render the
plates more uniform, they are sometimes wire-drawn, by
passing them through narrow holes, in a steel plate. The
plates, whether of gold, silver, or copper, when reduced
to their proper thickness, are next cut out into round
pieces, called blanks, or planchets. This cutting is per-
formed by a circular steel punch, of the size of the coin,
which is driven downward, by a powerful screw, and
passes through a corresponding circular hole, carrying
before it the piece of metal which is punched out. The
pieces, which are thus cut, are brought to the standard
weight, if necessary, by filing or rasping ; and the defi-
cient pieces, together with the corners, and pieces of the
plates, left by the circles, are returned to the melter.
The milling, by which the inscription, or other impres
oion, is given to the edge of the coin, is perfornied, by
rolling the coin edgewise, between two plates of steel, in
220 ARTS OF METALLURGY.
the form of rulers, each of which contains half of the en
graved edging. One of these plates is fixed, and the
other is movable, by a rack and pinion. The coin, being
placed between them, is carried along by the motion of the
rack, till it has made half a revolution, and received the
whole impression on its edge. The most important part of
the coining still remains to be done, and consists in stamping
both sides, with the appropriate device, or figure, in relief.
For this purpose, the circular piece is placed between
two steel dies, upon which the figures to be impressed are
sunk, or engraved, in the manner of an intaglio. The
two dies are then forcibly pressed together, by the action
of a powerful screw, to which is attached a heavy trans-
verse beam, which serves the purpose of a fly, and con-
centrates the force at the moment of the impression. The
coin is now finished, and is thrown out, when the screw
rises.
In the coining machinery erected by Boulton and Watt,
and introduced at the mint in England, the process is per-
formed by steam-power, and both the edges and faces ol
the money are coined at the same time.* By means of
this machinery, eight presses, attended by boys, can
strike nineteen thousand pieces of money in an hour, and
an exact register is kept by the machine, of the number of
pieces struck.
For the coining of medals, the process is nearly the
same as for that of money. The principal difference
consists in this, that money, having but a small relief, re-
ceives its impressions at a single stroke of the engine ;
whereas, in medals, the high reUef makes several strokes
necessary ; for which purpose, the piece is taken out from
between the dies, heated, and returned again. This
process for medallions is sometimes repeated, as many as
a dozen or more times, before the full impression is given
them. Some medallions, in a very high relievo, are
obHged to be cast in sand, and afterwards perfected by be-
ing sent to the press.
Plating. — The great value of silver, and the useful
* A particular account of this machinery is given in the London
Mechanic's Magazine, vol. iii.
PLATING. 221
property which it possesses, of resisting oxidation, has
given rise to the art oi platings in which vessels and uten-
sils of other metals, but, chiefly, of copper, are covered
with a thin coating of silver, so as to protect them from
the influence of the atmosphere. Plating is sometimes
executed by heating the articles, which are to be coated,
and rubbing on them portions of leaf-silver, with a steel
burnisher, till it adheres. But it is performed, in a better
manner, by plating solid ingots of, copper, and afterwards
working these into any shape desired. The ductihty of
the coating of silver causes it to be extended, and drawn
out with the copper, so that the latter metal never appears
at the surface. The copper, used in plating, is alloyed
with a httle brass. Great care is taken, in casting, to
form the ingots sound, and free from pores, or flaws.
The surface of the ingot is cleaned with a file, and a thin
plate of silver is apphed to one or to both sides, accord-
ing to the article to be manufactured. A saturated so-
lution of borax is then insinuated between the edges, the
object of which is, to protect the copper from oxidation,
which would otherwise prevent the silver from adhering.
The ingot is then carried to the furnace, and exposed to
lieat, until the metals adhere to each other. Their adhe-
sion is owing to the formation of an alloy between the
silver and copper, which, being fusible at a lower tem-
perature than either of the metals, acts as a solder, to
unite them together. The ingot is then rolled into sheets,
by passing it, repeatedly, between iron rollers, annealing
it, from time to time, as it becomes hard and brittle.
The plated sheets, which are thus obtained, are form-
ed into articles of different kinds, by hammering them in
moulds, corresponding to the intended shape. When
vessels are to be made, they are formed in pieces of a
convenient shape, and these are soldered together, with
an alloy of silver, copper, and brass. Mouldings, and
other ornamental parts, are made by hammering the met-
al in steel dies, or rolling it between steel rollers, upon
which the pattern is cut. As the edges of plated ware
are most hable to be injured by wear, they are common-
ly protected by what are called silver edges. These are
19*
222 ARTS OF METALLURGY.
formed of a shell of silver, rolled out, or hammered m
dies, and having its inside filled up with a mixture of tin
and lead. When finished, these edges are soldered to
the vessel. The handles, feet, and solid parts, of vessels
are often made in the same way. Plated baskets, and
other light articles, are made from copper cyhnders, cov-
ered with silver, and afterwards drawn into wire.
Plating on iron, as it is used for the buckles of har-
nesses, and other ornaments, is executed, by first covering
the iron with a coating of tin, and then applying, closely
to the surface, a thin plate of silver. The union is effect-
ed by a moderate heat, suflicient to melt the tin, and form
an alloy ; and it is aided by the use of a resinous flux.
COPPER.
Extraction. — The various sulphurets of copper are
the most abundant of its ores ; and of these, the most so
is copper pyrites. The malachite, red copper ore, and
others, are generally associated with these, in small quan-
tities. Copper mines are wrought in many countries,
but those of Sweden are said to furnish the purest cop-
per of commerce. The sulphurets are the ores from
which copper is usually extracted. The ore is roasted
by a low heat, in a furnace, with which flues are connec-
ted, in which the sulphur, that is volatilized, is collected.
The remaining ore is then smelted, in contact, with the
fuel. The iron present in the ore, not being so easily
reduced, or fused, as the copper, remains in the scoria,
while the copper is run out. It often requires repeated
fusions ; and, even after these, it may be still alloyed with
portions of metals, which are not volatile, and are of
easy fusion. Hence, the copper of commerce is never
altogether pure, but generally contains a little lead, and
a smaller portion of antimony.
The carbonates of copper, reduced by fusion, in con-
tact with the fuel, afford a purer copper, as does also the
solution of sulphate of copper, which is met with in some
mines, the copper being precipitated in its metalhc state,
by immersing iron in the solution. The precipitate, which
is thus formed, is afterwards fused.
WORKING. BRASS. 223
fVorking. — Copper, being ductile and easily wrought,
IS applied to many useful purposes. It is formed into
thin sheets, by being heated in a furnace, and subjected
to pressure between iron rollers. These sheets, being
both ductile and durable, are applied to a variety of uses,
such as the sheathing of the bottoms of ships, the cover-
ings of roofs and domes, the constructing of boilers and
stills, of a large size, &c. Copper is also fabricated
into a variety of household utensils, the use of which,
however, for preparing or preserving articles of food, is
by no means free from danger, on account of the oxidize-
ment, to which copper is liable. It has been attempted
to obviate this danger, by tinning the copper, or apply-
ing to its surface a thin covering of tin. This method
answers the purpose, as long as the coating of tin re-
mains entire.
Copper may be forged into any shape, but will not bear
more than a red heat, and, of course, requires to be heat-
ed often. The bottoms of large boilers are frequently
forged with a large hammer, worked by machinery. The
bolts oi copper, used for ships, and other purposes, are
either made by the hammer, or cast into shapes, and
roFed. The copper cylinders, used in calico printing,
are either cast sohd, upon an iron axis, or are cast hollow,
and fitted upon the axis. The whole is afterwards turn
ed, to render the surface true.
BRASS.
Brass is an alloy of copper and zinc. The propor-
ons of these two metals differ, in almost every place
n which brass is manufactured : and the proportion of
zinc is found, in different specimens, to vary from twelve
to twenty-five parts, in a hundred. The alloy is com-
nonly made from the ores of zinc mixed with copper,
and with a sufficient quantity of charcoal, to reduce
them to a metallic state. The volatihty of the zinc gives
it a tendency to escape in vapor, on which account, the
combination is effected at a lower heat, than that which
would be necessary to melt the copper. Several other
alloys, of the same metals, are also known in the arts, dif-
224 ARTS OF METALLURGY.
fering in the proportions of the ingredients ; such as pinch
beckj prince' s-metal^ tombac^ Bath-metal^ &c.
Manufacture. — The value of brass, in the arts, con-
sists, in its bright color, in its being more fusible than
copper, and in its being more easily wrought with com-
mon tools. In the working of brass, the larger articles,
as well as those of comphcated forms, are cast in moulds.
When it is intended, for economy of the metal, that the
aiticle shall be hollow, as in the case of andirons, &c.,
it is cast in halves, or pieces, which are afterwards sol-
dered together, and turned in a lathe, or otherwise pol-
ished. Brass is also rolled into thin sheets, and drawn
into wire. A variety of figured and ornamental articles
are made, by stamping it in dies, or moulds. Brass
knobs and similar implements, if large, are made in pieces,
and soldered. The wheel-work of time-pieces, and of
other machinery, which is not subjected to great strain or
wear, is usually made of brass. The comparative softness
of this alloy permits it to be cut with thin saws, and to be
turned in a lathe, with much greater ease than iron.
Buttons are either struck out of sheets of brass, with
a circular punch, driven by a fly-press, or they are cast,
in large numbers at once, in a mould, or flask of sana.
The e?/e, or shank, of the button, is made separately, by
a machine, and soldered on, if the button has been cut
out by the punoh. If the button is cast, the eye is pre-
viously placed in the mould, so that its extremity is im-
marsed in the centre of the melted metal. If the button
is to be plain, its surface is planished by the stroke of a
smooth die ; and, if figured, it is stamped with an en
graved die. The edges are afterwards turned off, in a
lathe. The gilding of brass buttons is performed, by cov-
ering them with an amalgam of gold and mercury, fro...
which the mercury escapes, when heated, and leaves the
gold. White-metal buttons are made of an alloy of brass
and tin, and subsequently coated with tin. The brass
eyes of pearl buttons are inserted, by drilling a conical
hole, which is largest on the inside, in the mother of
pearl, or shell, of which the button is made. The eye,
naving an extremity like a hollow cone, is then driven in,
till it spreads, and fills the cavity.
PINS. BRONZE. 225
Pins are made of brass wire, cut into proper lengths.
The pieces are pointed, by turning them with the fingers,
upon stones or steel mills. The heads are cut from a
spiral coil of wire, in pieces of a suitable length ; and, af-
ter being placed upon the pins, are shaped and fastened,
by the stroke of an instrument like a hammer. Several
machines have been invented for this manufacture, one of
which makes a solid head, from the body of the pin itself.
Pins are whitened, by immersing them in a vessel, con-
taining tin and lees of wine, and are polished, by agita-
ting them with bran, in a revolving cask.
Bronze. — A series of alloys is formed, from the com-
bination of copper with tin. The combination appears
to have a tendency to form in certain proportions, regulat-
ed, in some measure, by the specific gravities and fusibil-
ities of the metals ; for, when kept in fusion, and allowed
to cool without agitation, two alloys are formed, the under
part of the mass being one of copper, with a small portion
of tin, and the upper part tin, with a small proportion of
copper, while, between these, there is, probably, a grada-
tion. By agitation, this separation is counteracted. In
general, tin lessens the ductility of copper, while it ren-
ders it more hard, rigid, and sonorous ; these qualities
being possessed, in various degrees, by the different alloys,
according to their proportions ; the hardness and brittle-
ness being greater, as the tin predominates. The densi-
ty of the compound is, also, always greater than the mean
density ; the contraction, from the combination, being
about one eighth. The principal of these alloys are bronze,
gun-metal, from which pieces of artillery are cast, bell-
■metal, and speculum-metal, which has been used for the
mirrors of reflecting telescopes. Bronze is one of those,
in which the proportion of tin is least,. not exceeding ten
or twelve parts in one hundred. It is of a grayish yellow
color, harder than copper, less liable to rust, and more
fusible, so as to be easily cast in moulds. Hence it is
employed in the casting of statues. The metal, from
which pieces of artillery are cast, is of a similar compo-
sition, containing rather less tin. It appears that an al-
loy, very similar to bronze, was much in use among the
226 ARTS OF METALLURGY.
ancients ; and swords, darts, and other warlike instru-
ments, were formed of it, as were also various utensils.*
When the proportion of tin is increased, the alloy is
rendered more brittle and elastic, and, at the same time,
highly sonorous. Bell-metal is an alloy of this kind, in
which the proportion of tin varies from one third to one
fifth of the weight of the copper, according to the size of
the bell, and the sound required.
When the proportion of tin is still greater, an alloy is
formed, called speculum-metal , which is of a white color,
and which, from the closeness of its texture, and its sus-
ceptibility of a fine polish, exceeds most metals in the
property of reflecting light. Hence it is used in forming
the speculum of reflecting telescopes. It has, also, the
advantage of not being liable to tarnish, on exposure to
the air. The proportion in which these quahties w^ere
best attained, appeared, from the experiments of Mr.
Mudge, to be a little less than one part of tin, with two
parts of copper. The Chinese pakfong^ or white cop-
per, which is sometimes imported from that country, is
an alloy, according to Dr. Fyfe, of copper, zinc, nickel,
and iron. The article used in this country, and in Europe,
under the name of German silver^ is essentially an alloy
of copper, zinc, and nickel.
LEAD.
Extraction. — Lead, mineralized by sulphur, forms by
far the most abundant ore of the metal, and has been long
known to mineralogists by the name of galena. This is
the ore which is generally wrought, and from which nearly
* According to Dr. Pearson's experiments, made on various instru-
ments of this kind, the alloy appears to have consisted of about eight
or nine parts of copper, with one of tin ; and, as he justly remarks,
this alloy still affords the best substitute for iron or steel. While the
art, therefore, of manufacturing malleable iron was imperfectly known,
and difficult to be practised, it must have been much used. The hard-
ness of this alloy, observed in ancient arms, had even given rise to an
opinion, that the ancients were acquainted with a method of hardening
copper, which had been lost. Of this alloy, medals and coins were
also often formed, as appears from the experiments of Dize, on sever-
al Greek, Roman, and CJallic coins, which c?)nsisted of copper and tin
alone.
SHEET-LEAD. LEAL- PIPES. 227
all the lead of commerce is procured. The ore, after
being pounded, and freed from the admixture of any stony
matter, by washing, is fused in a furnace, with the addi-
tion of lime, which combines with the sulphur of the sul-
phuret ; the lead is melted, and run out by an aperture,
towards the bottom of the furnace. When the native salts
of lead are found with the galena, so as to render it of
in..portance to work them, they are selected, until a suffi-
cient quantity be obtained. They are then roasted, to
expel the volatile matter, and are afterwards fused, in con-
tact with the fuel, with an addition of lime. The lead ob-
tained from galena, sometimes contains so much silver, as
to be subjected to an additional process to separate the
silver. In this case, the lead is oxidized in a furnace ;
a current of air being directed on its surface, when in fu-
sion, by bellows. Towards the end of the operation, the
silver remains, with a small portion of lead, from which
it is freed, by cupellation ; and the oxide of lead is either
applied to the purposes for which it is used, or is reduced
to the metallic state.
Manufacture. — Lead, being fusible at a low tempera-
ture, requires only to be cast in smooth moulds, to form
weights, bullets, and other articles of small size. The
linings of cisterns, and the coverings of roofs, gutters,
&c., are made of sheet-lead ; pumps, and aqueducts, of
leaden pipes.
Sheet Lead, of the thicker kinds, is cast upon large
tables, covered with sand, and having an elevated rim.
The melted lead is poured upon the surface, out of a box,
which moves upon rollers across the table, and is spread
out with a uniform thickness, by passing over it a straight
piece of wood, called a strike. The sheets, thus cast,
are afterwards rendered thinner, by reducing them between
rollers. The sheet-lead with which tea-chests are lined,
is an alloy of lead and tin, and is made by the Chmese,
by suddenly compressing the melted metal between flat,
polished stones.
Lead pipes, for conveying water, may be made in vari-
ous ways. They were at first formed of sheet lead, bent
round a cylindrical bar, or mandrel, and soldered ; but
228 ARTS OF METALLURGY.
these pipes are liable to crack and leak, especially when
bent. A second method is, to cast a short tube of lead
in a cylindrical mould, with a core. This tube, when
cold, is drawn nearly out of the mould, and a fresh por-
tion of melted lead poured in, at apertures in the sides
of the mould. The melted lead unites with the tube,
])reviously formed, so as to increase its length ; and by
repeating the process, any length of pipe may be pro-
duced. But pipes, cast in this manner, are found to have
imperfections, arising from flaws and air bubbles. A
third method, which is now most commonly practised, is
to cast a short, thick tube of lead, upon one end of a
long, polished, iron cylinder, or mandrel, gf the size of
the bore of the intended pipe. The lead is then reduced
in size, and drawn out in length, either by drawing it on
the mandrel, through circular holes, of different sizes, in
a steel plate ; or by rolling it between contiguous rollers,
which have a semi-circular groove, cut round the circum-
ference of each. A fourth mode, invented by Mr. Bra-
mah, consisted in forcing melted lead, by means of a
pump, into one end of a mould ; while it was discharged,
in the form of a pipe, at the opposite end. 'Care was
taken, so to regulate the temperature, that the lead should
chill, just before it left the mould.
Leaden shot consist of drops of metal, which are dis-
charged, in a melted slate, from small orifices, and cool
in falling. The best shot are cast in high towers, built
for the purpose. The lead is previously alloyed with a
portion of arsenic, which increases the cohesiveness of its
particles, and causes it to assume, more readily, the glob
ular form. It is melted, at the top of the tower, and
poured into a vessel, which is perforated at bottom, with
numerous small holes. The lead, after running through
these perforations, immediately separates into drops, which
cool, in falling through the height of the tower, and are
received in a reservoir of water, at bottom, to break the
force of the fall. The shot are then proved, by rolling
them down an inclined board. Those which are irregulai
m shape roll off at the sides, or stop, while the spherical
ones continue to the end. They are then assorted, by
TIN. BLOCK TIN. TIN PLATES. 229
passing them through wire sieves of different fineness.
The glazing is given, by agitating them with small quan-
tities of black lead.
Shot is sometimes made, mechanically, by cutting sheets
of lead into cubes, and agitating these, for a long time, in
a cylindrical vessel, turned upon an axis. The attrition,
thus produced, communicates a globular form to the cubes.
TIN.
Native oxide of tin, or tinstone^ as it is commonly nam-
ed, is the only ore that is wrought, to obtain this metal.
Being freed, by washing, from the intermixture of any
stony matter, it is roasted, and then fused, in contact with
the fuel, by a moderate heat. The tin of Cornwall is
supposed to be purer than the German tin, though it is
still inferior to the tin from India.
Block-tin^ consisting of the metal in its solid state, is
used for vessels which are not exposed to a temperature
much exceeding that of boiling water. Vessels of this
kind, being not readily tarnished, form a cheaper substi-
tute for silver and plated ware. A kind of ware, de-
nominated Biddery ware, consists of tin vessels, alloyed
with a litde copper, and having their surface made black
by the application of substances, containing nitre, com
mon salt, with sal ammoniac. Tin-foil is made by rol
ling, in the same way as the plates for tinned iron here-
after described. It is also sometimes hammered. The
most extensive use, however, to which metalhc tin is ap-
pHed, is to form a coating for other metals, which are
stronger than itself, but at the same time more liable to
oxidation by exposure to the air.
Tin plates, which constitute the material of the com-
mon tin ware, so extensively used, are thin sheets of iron,
coated with tin. The mode of rolling these sheets wil]
be described under the head of Iron. To prepare them
for tinning, they are steeped in water, acidulated with
muriatic acid, and then heated, scaled, and rolled, to re-
move all oxide, and enable the tin to adhere to the iron.
The (in is kept melted in oblong, rectangular vessels, and
to preserve its surface from oxidation, a quantity of melt-
II. 20 XII.
230 ARTS OF METALLURGY.
ed fat and oil is kept floating upon it. The iron plates
are taken up with pincers, and immersed in the tin for
some time. When withdrawn, they are found to have
acquired a bright coating of the tin, which adheres closely,
owing to the formation of an intermediate alloy. The
dipping is repeated twice, or more times, according to
the thickness of the coat intended to be given, and also to
produce a smooth surface, and, between these processes,
the tin is equahzed with a brush.*
Various other articles of iron, such as spoons, nails,
bridle-bits, small chains, &ic. are coated with tin, by im-
mersing them in that metal, while in a state of fusion.
From the affinity between tin and copper, a thin layer of
the former metal can be easily applied to the surface of
the latter ; and this practice of tinning, as it is named, is
often employed, to prevent the erosion, or rusting, of
copper vessels, and the noxious impregnation which they
would otherwise communicate to liquors kept in them.
The surface of the copper is polished, so as to be quite
bright ; sal-ammoniac is applied to it, when hot, by which
the oxidation appears to be prevented ; or pitch is some-
times used, for the same purpose. The melted tin, or,
sometimes, an alloy of tin and lead, is then applied to the
surface of the copper, to which it readily adheres.
Silvering of Mirrors. — The surfaces, best adapted for
reflecting light, are those of polished metals. To con-
stitute a good reflector, it is necessary that a metal should
be susceptible of an equal, unbroken, and exquisite, pol-
ish, and that it should retain this polish, without being
tarnished by the atmosphere. Speculum-metal is, chiefly,
employed for reflecting surfaces, in telescopes ; but, for
common purposes, an amalgam of tin and mercury is used,
m a state of adhesion to glass. The use of the glass is,
in the first place, to produce a smooth surface, in the
amalgam ; and, afterwards, to protect it from oxidation by
the atmosphere.
In the silvering of plain looking-glasses, a flat, hori-
* For a full account of tho present mode of manufacturing tin plate,
gee Parkes's Chemical Essays, vol. ii.
IRON. 231
tontal slab of stone is used, as a table. Phis is smoothly
covered with paper, and a sheet of tin-foil, equal to the
size of the glass, is extended over it. A quantity of
mercury is then laid upon the tin-foil, and immediately
spread over it, with a roll of cloth, or a hare's foot. Af-
terwards, as much mercury, as the surface will hold, is
poured on. While this mercury is yet in a fluid state,
the plate of glass is slid on, at the edge of the table, so as
to pass over the tin-foil, driving the superfluous mercury
before it. In this way, any bubbles of air and particles
of dust are prevented from getting between the glass and
the metal, and an uninterrupted coating is formed. In
order to force out the remaining liquid mercury, the glass
is placed in a sloping position, to allow the mercury to
drain ofl', after which, heavy weights are placed upon the
glass, and suffered to remain, for some time. The por-
tion, which is left, amalgamates with the tin, and forms a
permanent reflecting surface, the smoothness and perfec
fion of which depend upon the degree of regularity and
polish, which the glass possesses.
In silvering concave and convex mirrors, instead of
A stone table, the tin-foil is spread upon a plaster mould,
previously cast on the surface of the glass hself. The
inside of glass globes is silvered, by pouring into them a
fusible alloy of tin, lead, bismuth, and mercury, the heat
of which, when liquid, is not sufficient to break the glass
By turning the globe about, a thin metallic coating is de-
posited on the whole interior surface.
IRON.
The properties which iron possesses, in its various
forms, render it the most useful of all the metals. The
toughness of malleable iron adapts it to purposes, where
great strength is required ; while its combination of diffi-
cult fusibility with the property of softening by heat, so
as to admit of forging and welding, renders it capable of
being easily worked, and of withstanding an intense heat.
Cast-iron, from its cheapness, and the facility with which
Jts form is changed by fusion, is made the material of
numerous structures and machines. Steel, which is the
232 ARTS OF METALLURGY.
most important compound of iron, exceeds all other me-
tals, in the combination of hardness and tenacity ; and
hence, it is particularly adapted to the fabrication of cut-
ting instruments. It is equally superior in elasticity, a
quality by which it is suited to be the spring of motion,
in various machines.
Smelting. — The principal ores, which are wrought for
the extraction of iron, are the different species of the na-
tive oxides. The process is somewhat different, as car-
ried on, in different countries, and as adapted to different
ores ; but the following is the general outline of it, as it
is conducted on the haematite bog-ores, and other oxides
of iron.
The blast-furnace, in which the operation is conducted,
is a large pyramidal stack, made of brick or hewn stone,
from twenty to sixty feet high, having its internal cavity
shaped like an egg, with its large end downwards, and
lined with fire-brick or stone.
The ore is first roasted, with a strong heat, to expel
the carbonic acid, and any portion of sulphur, or other
volatile matter, that may be present. The remaining ore
is put into a furnace, of a conical form, with charcoal, or
with coke, and exposed to a heat, rendered sufficiently
intense by a blast of air, urged through the furnace. A
quantity of lime is, at the same time, added to the ore
and fuel ; the advantage of which appears to be, that in
combination with the argillaceous and sihcious substances,
generally contained in the iron ores, it acts as a flux, to
vitrify the foreign matter, and thus facilitate the separation
of the melted metal. The proportions of these are ex-
tremely various, according to the nature of the ore. When
the furnace is once charged, the charge is renewed at
the upper part, as fast as the materials sink, and the pro-
cess is carried on, for a long time, without interruption.
During this process, the oxygen of the oxide of iron unites
with one portion of the carbon, and the metal with anoth-
er, producing carbonic acid, and carburet of iron ; while
the earthy substances, together with a little oxide of iron,
enter into combination, forming a vitreous substance call-
ed slag, or scoria, and which, being lighter than the me
CRUDE IRON. CASTING. 233
tal, rises upon its surface. The slag is drawn oiF, by an
opening, and the melted metal is collected in a cavity, at
bottom, from which, as it accumulates, it is conveyed off,
at intervals, into moulds.
A vast improvement, in regard to the saving of fuel,
has been produced, in late years, by the introduction of
the hot blast, in smelting furnaces. The fire, in this case,
is blown by air, previously heated ; the combustion be-
comes more effective ; and a saving of tw^o thirds of the
fuel is said to be produced.
Crude Iron, — The metal thus obtained, is named pig-
iron, and crude, or cast-iron. It is far from being pure,
containing, always, more or less oxygen and carbon ; and,
often, several other heterogeneous ingredients, such as
manganese, and the metaUic bases of lime, clay, and silex,
with portions of unreduced ore and charcoal. The oxy-
gen is, partly, a portion of what was originally combined
with the metal, in the ore, and partly, perhaps, derived
from the blast of air, which is driven through the furnace,
and necessarily presented to the metal, in a state of fusion
Hence, the qualities of cast-iron are very various, accord
ing as one or other of the principles predominates.
Iron, in this state, is readily capable of being fused,
and cast into moulds. It is, however, much more brittle,
than w^hen pure, and cannot be wrought or flattened, un-
der the hammer. Hence, it is altogether unfit for many
purposes, to which pure or malleable iron is, from its te-
nacity and softness, w^ell adapted.
Casting. — Iron, as well as brass, and other metals,
which melt at temperatures above ignition, is cast in
moulds, made of sand. The kind of sand, most employ
ed, is loam, which possesses a sufficient portion of argil-
laceous matter, to render it moderately cohesive, when
damp. The mould is formed, by buryniti, in the sand, a
wooden pattern, having exactly the shape of the article
to be cast. The sand is most commonly enclosed in
flasks, which are square frames, resembling wooden box-
es, open at top and bottom. If the pattern be of such
form, that it can be lifted out of the sand, without derang-
ing the form of the mould, it is only necessary to make
20*
234 ARTS OF METALLURGY.
an impression of the pattern, in one flask.; and articles
of this kind are sometimes cast in the open sand, upon
the floor of the foundry. But when the shape is such,
that the pattern could not be extracted, without breaking
the mould, two flasks are necessary, having half the mould
formed in each. The first flask is filled with sand, by
ramming it close, and is smoothed ofl*, at the top. The
pattern is separated into halves, one half being imbedded
m this flask. A quantity of white sand, or burnt sand,
IS sprinkled over the surface, to prevent the two flasks
from cohering. The second flask is then placed upon
the top of the first, having pins to guide it. The other
half of the pattern is put in its place, and the flask is filled
with sand, which, of course, receives the impression of
the remaining half of the pattern, on its under side. After
one or more holes are made in the top, to permit the met-
al to be poured in, and the steam and air to escape, the
flasks are separated, and the pattern withdrawn. When
the flasks are again united, a perfect cavity, or mould, is
formed, into which the melted metal is poured.
The arrangement of the mould is, of course, varied,
for different articles. When the form of the article is
complex and diflicult, as in some hollow vessels, crooked
pipes, &c., the pattern is made in three or more pieces,
which are put together, to form the moulds, and after-
wards taken apart, to extract them. In some other ir-
regular articles, as andirons, one part is cast first, and
afterwards inserted in the flask which is to form the other
part.
The metal for small articles is usually dipped up, witli
iron ladles coated with clay, and poured into the moulds.
In large articles, such as cannon, the mould is formed in
a pit, dug in the earth, near the furnace, and the melted
metal is conveyed to it, in a continued stream, through a
channel communicating with the bottom of the furnace.
Cannon balls are sometimes cast in moulds, made of
iron ; and to prevent the melted metal from adhering, the
inside of the mould is covered with powder of black lead.
Rollers for flattening iron are also cast in iron cases.
This; method is called chill- castings and has, for its ob
MALLEABLE IRON. FORGING. 235
ject, the hardening of the surface of the metal, by the
sudden reduction of temperature, which takes place in
consequence of the superior conducting power of the iron
mould. These rollers are afterwards turned smooth, in a
powerful lathe, which has a slow motion, that the cutting
tool may not become heated by the friction.
Malleable Iron. — To obtain pure iron, that is, to free
crude iron from the oxygen, carbon, and other foreign
substances, contained in it, it is subjected to two opera-
tions,— melting, and forging. The fusion is performed
in. difl'erent furnaces. The melted metal is, in some cases,
run out, to free it from the scoria which has separated ;
and this process is repeated, until the iron attains a degree
of consistence, sufficient to be submitted to the action of
the forge-hammer. But, more commonly, the metal is
kept in fusion, in a reverberatory furnace, called a pud-
dling-furnace, where it is raised to a very high tempera-
tur-e. The liquid is stirred frequently, to facilitate the
combination of the carbon and oxygen. At length, a
lambent blue flame appears on its surface, probably from
the formation and disengagement of carbonic oxide ; and,
after some time, the fluidity of the metal diminishes, until
it, at length, assumes the consistence of a stiff paste. It
IS then suDjected to the action of a very large hammer,
or to the more equable pressure of rollers, by which a
portioa of oxide of iron, carbon, and other heterogeneous
substances, not consumed during the fusion, are forced
out. The iron, in this state, is no longer granular in its
texture, but is soft, ductile, and malleable, and much less
fusible. It is then named wr ought-iron., forged., or bar
iron, as it is generally formed into long bars. A consid-
erable loss of weight attends the process, from the dissi-
pation of the foreign substances, contained in the crude
iron, and from the oxidation of the surface of the metal.
The operation is generally perform.ed on the varieties
called white, or gray, crude iron.
Forging. — Forging consists in changing the form of
iron, and other malleable metals, by percussion, applied
to them, while they are softened by heat. Iron, when
exposed to the action of great heat, becomes highly mal-
236 ARTS OF METALLURGY.
leable and ductile. It is also capable of welding, at a
sufficiently high temperature. Most other metals have
their malleabihty improved, by a certain degree of heat,
but become brittle, if the heat is carried near to then- fu-
sing point. The strength and quality of iron, on the
contrary, are improved, by forging at a strong white heat,
since the parts become consolidated, and the flaws oblit
erated, by hammering, at a welding temperature.
The joint action of the heat and current of air. used ii
forges, tends to oxidate, rapidly, the surface of iron. Th'
oxide which is formed has some tendency to vitrification
when combined w^ith silicious matter. Hence it is a com
mon practice among workmen, to immerse the iron in sand .
when it is near to a welding heat. A vitreous coating is,
by this means, formed, which protects the surface of th •
iron from further oxidation. This coating would prevent
the different pieces from uniting, by welding, were it not
that its fluidity causes it to escape, while under the action
of the hammer.
The forging, at the furnaces, of large masses of iron,
called blooms, is performed by the aid of tilt-hammers, as
is also that of anchors, and various other massive imple-
ments, and parts of machines. Bars of iron are common-
ly rolled, and when heavier articles, such as anchors, are
to be made, a sufficient number of bars, for the purpose,
are welded together.
. A tih-hammer, of the kind used in iron-works, is shown
in PI. III., Fig. 2. x\B, is the hammer, which turns
upon the fulcrum, C. At D, is a wheel, or cyhnder,
furnished w^ith wipers, [abc, &c.,] each of which, as it
passes, strikes the end. A, of the helve, and causes the
liammer-end, B, to rise. The hammer then desornds,
with its own weight, and is accelerated by the recoil of
the end. A, from the fixed obstacle, E. The wipers
may be indefinitely varied, in number and position, and
are sometimes apphed, on the other side of the fulcrum.
The recoil, likewise, is sometimes produced by a spring,
placed over the end, B, of the hammer. The motion
of these engines is extremely rapid, and is commonly reg
ulated by a fly-wheel.
ROLLING AND SLITTING. 237
Rolling and Slitting, — Malleable iron is commonly-
wrought into those shapes which have flat, parallel sur-
faces, by submitting it to compression, between rollers.
Bars, plates, and sheets, of iron are formed, in this way.
A pair of heavy cylindrical rollers, made of iron, chill-
cast, and turned snwoth, are connected together by strong
iron bearings, a space being left between them, equal to
the intended thickness of the metal, which is to be rolled.
This distance is varied, by adjusting it with powerful
screws. The iron, which is to be rolled, is prepared,
by heating it red hot, and, in this state, it is presented to
the rollers. As soon as any part has entered, so as to
fill the space between the rollers, the friction, or adhesion,
becomes sufficient to draw in the remainder, in opposition
to the force with which the metal resists cqmpression.
The iron, in passing through, is compressed into a uni-
form plate, of equal thickness, and is, at the same time,
extended in length, but is very little increased in breadth.
As the rollers usually move with considerable velocity,
the heated iron may be passed, several times, between
different pairs of rollers, before it cools. To prevent the
rollers from becoming heated, a continual stream of water
is let fall upon their surface.
As the principal extension, w'hich plates receive, is in
I longitudinal direction, it is necessary to vary their po-
sition, when it is desired to increase their width. This is
sometimes done, by passing them in an obhque direction ;
but, in making sheet-iron and wide plates, it is necessary
to pass the pieces through the rollers, in the direction of
their breadth, as well as length, that they may be extend-
ed in both directions. Very thin plates, like those used
for tinned iron, are repeatedly doubled, and passed be-
tween the rollers, so that, in the thinnest plates, sixteen
thicknesses are rolled, together, care being taken to change
their relative positions, and to interpose oil, to prevent
them from cohering. The last rollings are performed,
while the metal is cold. Bars which are square, round;
and of various other shapes, are formed, between rollers
which have grooves cut upon their circumferences, cor-
responding, in shape, to half the bar to be made. Even
238 ARTS OF MFTALLURGY
rails of malleable iron, for rail-roads, have lately been
made between rollers, formed for the purpose. . And, at
some furnaces, where malleable iron is made, the forge-
hammer is dispensed with, and reliance is placed on the
rollers, alone, to consolidate anc^ equalize the masses of
metal.
Slitting rollers, or those intended for dividing plates
of iron into narrow rods, are formed with elevated rings
upon their circumferences, which reciprocally enter be-
tween each other, their edges being angular, and passing
in close contact with each other, so as to cut like shears.
These rings are separately made, so tha* tbey can be re-
moved from the rollers, for the purpose of sharpening
them, when necessary.
Wire Drawing. — The manufacture of w^ire consists, in
drawing a piece of metal through a conical hole in a
steel plate, which forms it into a regular cylindrical fila-
ment. The size of this filament may be reduced, and
the length extended, indefinitely, by passing it through
successive holes, which gradually diminish in diameter.
To prepare the iron for drawing, it is first subjected to
the action of the hammer, till it is reduced to a size tha*
will admit of its being drawn through the plate. Some
times, the iron is prepared by rolling ; but the best wire i
produced, when the metal has been thoroughly hammered
The rod of iron which has been prepared, in this man
ner, is next drawn through one of the larger holes in thi
steel plate. Various machines are employed, to over
come the resistance which the plate opposes to the com
pression and passage of the wire. In general, the end
of the wire is held by pincers, and as fast as the wire is
drawn through the plate, it is wound upon a roller, by the
action of a wheel and axle, or other power. Sometimes,
a rack and pinion is employed, for this purpose, and
sometimes, a lever, which acts at intervals, and takes fresh
hold of the wire, each time that the force is applied.
The finer kinds of wire are made from the larger, by
repeated drawings, each of which is performed through a
smaller hole than the precedin^o'. As the metal becomes
stiff and hard, by the repetition of this process, it is nee-
NAIL-MAKING. GUN-MAKING. 239
essary to anneal it, from time to time, to restore its duc-
tility. It is also occasionally immersed in an acid liquid,
to loosen the superficial oxide which is formed, in the
process of annealing.
JVai7 Making. — Nails are made, both by hand, and
by machinery. Wrought-nails are made, singly, at the
forge and anvil, by workmen who acquire, from practice,
great despatch in the operation. Machines have been
made, for making these nails perfectly, and with rapidi-
ty ; yet they have not come into general use, owing to
the cheapness of the product "by manual labor. Cut-
nails are made, almost wholly, by machinery, invented
in this country. The iron, after having been rolled, and
slit into rods, is flattened into plates, of the thickness in-
tended for the nails, by a second rolling. The end of
this plate is then presented to the nail-machine, by a work-
man, who turns the plate over, once, f6r every nail. The
machine has a rapid reciprocating motion, and cuts oiT,
at every stroke, a wedge-shaped piece of iron, constitu-
ting a nail without a head. This is immediately caught,
near its largest end, and compressed between gripes.
At the same time a strong force is applied to a die, at the
extremity, which spreads the iron, sufficiently to form a
head to the nail. Some nails are made of cast-iron, but
these are always brittle, unless afterwards converted into
malleable iron, by the requisite process.
Gun Making. — Cannon, carronades, &c., whether of
iron or brass, are cast in sand, and afterwards bored.
Muskets and fowhng-pieces are forged from bars of mal-
leable iron. The bar is first flattened by hammering,
till it attains the requisite width. It is then made into a
tube, by turning it over a mandrel, or cylindrical rod, of
a size which is smaller than that of the intended bore.
The edges are made to overlap each other, about half an
inch, and are firmly welded together. The whole is then
consolidated and strengthened, by hammering it, for some
time, in semi-circular grooves, on a swage, or anvil, which
is furrowed for the purpose. To render the barrel smooth,
on (he inside, and perfectly true, it is afterwards bored
out, with an instrument somewhat larger than the man
240 ARTS OF METALLURGY.
drel ; and several such instruments, of different sizes, ar«
employed, in succession. The breech of the barre is
closed, by a strong plug, which is firmly screwed in, at
the extremity. The projecting parts of the barrel, such
as the sight, and the loops which confine it to the stock,
are soldered on. The construction of the lock, and oth-
er appendages, is readily understood, from inspection.
Steel. — When malleable iron is re-combined with car-
bon, in a much smaller proportion, it forms steel. Differ-
ent methods are followed, to form this combination. The
product varies, according to the method pursued, and is
also effected, by the introduction of other substances into
the combination. The best steel is made from Swedish
and Russian iron.
The general method of forming steel is, by the process
of cementation. A furnace is constructed, of a conical
form, in which are two large cases, or troughs, of fire-
brick, capable of holding some tons of iron. Beneath
these, is a long grate, on which the fuel is placed. On
the bottom of the case, is placed a layer of charcoal dust ;
over this, a layer of bars of malleable iron ; over this,
again, a layer of charcoal powder ; and the series of
alternate layers of charcoal and iron is thus raised to a
considerable height. The whole is covered with clay,
to exclude the air ; and flues are carried through the pile
from the furnace, so as to communicate the heat more
completely and equally. The fire is kept up, for eight
or ten days. The progress of the cementation is dis-
covered, by withdrawing a bar, called the test-bar, from
an aperture in the side. When the conversion of iron
into steel appears to be complete, the fire is extinguished ;
the whole is left to cool, for six or eight days longer, and
is then removed.
The iron, prepared in this manner, is named blistered-
steel, from the blisters which appear on its surface. To
render it more perfect, it is subjected to the action of the
hammer, in nearly the same manner which is practised
with forged iron ; it is beat very thin, and is thus ren-
ered more firm in its texture, and more convenient in its
^orm. In this state it is often called tilted-steel. When
ALLOCS OF STEEL. 241
the bars are exposed to heat, in a furnace sufficient to
soften them, and afterwards doubled, drawn out, and
welded, the product is called shear-steel. Cast-steel is
made, by fusing bars of common blistered-steel, with a
flux of carbonaceous and vitreous substances, in a large
crucible, placed in a wind-furnace. When the fusion is
complete, it is cast into small bars, or ingots. Cast-steel
is harder and more elastic, has a closer texture, and re-
ceives a higher polish, than common steel. It is capable
of still further improvement, by being subjected to the
action of the hammer.*
Steel is generally prepared from malleable iron. It can
also be formed from crude cast-iron, as in Mr. Lucas's
method, hereafter described. Several varieties of cast-
iron have been used for this purpose. The crude iron
from certain ores, as the sparry iron ore, is capable of this
conversion. The steel, thus obtained, is named natural
steel, but is inferior to that obtained by cementation.
Alloys of Steel. — Messrs. Stodart and Faraday have
succeeded in making some useful alloys of steel with oth-
er metals. f Their experiments induced them to believe,
that the celebrated Indian steel, called icootz, is an alloy
of steel w^ith small quantities of silicium and aluminum ;
and they succeeded in preparing a similar compound,
possessed of all the properties of wootz. They ascer-
tained that silver combines with steel, forming an alloy,
which, although it contains only one five hundredth of its
weight of silver, is superior to wootz, or to the best cast-
steel, in hardness. The alloy of steel with one hundredth
part of platinum, though less hard than that with silver,
possesses a greater degree of toughness, and is, there-
fore, highly valuable, when tenacity, as well as hardness,
is required. The alloy of steel with rhodium even ex-
* Writers differ, Iq regard to the proportion of carbon contained in
cast-steel. Mr. Buttery, in Ure's Dictionary, states, that the amount
is less than in common steel, and that no charcoal is added, in making
it. He aUo states, that it does not melt, at a welding temperature,
but falls to pieces, like sand, under the hammer, and the parts refug«
to become again united.
t Philosophical Transactions, for 1822.
ir. 21 XII.
242 ARTS OF METALLURGY.
ceeds the two former, in hardness. The compound of
steel with palladium, and of steel with iridium and osmi-
um, is likewise exceedingly hard ; but these alloys cannot
be applied to useful purposes, owing to the rarity of the
metals of which they are composed. M. Berthier has
also produced a useful alloy, by combining with the steel
a small portion of chromium.
Case Hardening. — The process of case-hardening con-
sists in converting the surface of iron into steel, and is used
for giving a superficial hardness to various instruments.
It is effected, by enclosing the article which is to be case-
hardened, in a box, with some carbonaceous substance,
usually animal charcoal, and exposing it to heat, until the
surface is converted into steel. The same term is some-
times improperly applied to the method of chill-casting,
which has been already mentioned.
Tempering. — The most remarkable, as well as the
most useful, of the properties of steel is the power which
it has of changing, permanently, its degree of hardness, by
undergoing certain changes of temperature. No other
metal, says Thenard, is known to possess this properly,
and iron itself acquires it, only when it is combined with
a minute portion of carbon. If steel is heated to redness,
and suddenly plunged in cold water, it is found to become
extremely hard, but, at the same time, it is too brittle for
use. On the other hand, if it be suffered to cool very
gradually, it becomes more soft and ductile, but is defi-
cient in strength. The process of tempering is intended
to give to steel instruments a quality, intermediate between
brittleness and ductility, which shall insure them the propei
degree of strength, under the uses to which they are ex-
posed. For this purpose, after the steel has been suffi-
ciently hardened., it is partially softened, or let down to the
proper temper, by heating it again, in a less degree, or to
a particular temperature, suited to the degree of hardness
required ; after which, it is again plunged in cold water.
Different methods have been pursued, for determining
the temperature, proper for giving the requisite temper to
different instruments. One method is, to observe the
shades of color which appear on the surface of the steel
TEMPERING. 243
and succeed each other, as the temperature increases.
Thus, at four hundred and thirty degrees of Fahrenheit,
the color is pale, and but slightly inclining to yellow. This
is the temperature at which lancets are tempered. At
four hundred and fifty degrees, a pale straw-color appears,
which is found suitable for the best razors and surgical in-
struments. At four hundred and seventy degrees, a full
yellow is produced, suitable for penkives, common razors,
&c. At four hundred and ninety degrees, a brown color
appears, which is used to temper shears, scissors, garden-
hoes, and chisels intended for cutting cold iron. At five
hundred and ten degrees, the brown becomes dappled
with purple spots, which show the proper heat for tem-
pering axes, common chisels, plane-irons^ &c. At five
hundred and thirty degrees, a purple color is established ;
and, at this degree, the temper is given to table-knives
and large shears. At five hundred and fifty degrees, a
bright blue appears, used for swords and watch-springs.
At five hundred and sixty degrees, the color is a full blue,
and is used for fine saws, augers, &c. At six hundred
degrees, a dark blue, approaching to black, has become
settled, and is attended with the softest of all the grades
of temper, used only for the larger kinds of saws.
Another method of giving the requisite temper has
been practised upon various articles. The pieces of
steel are covered with oil or tallow, or put into a vessel
containing either of these ingredients, and heated over a
moderate fire. The appearance of the smoke, from the
oil or tallow, indicates the degree of heat. If the smoke
just appear, the temper corresponds with that indicated
by the straw-color, when the metal is heated alone. If
so much heat is applied, that a black smoke arises, this
points out a different degree of hardness ; and so on, till
the vapor catches flame. By this method, a number of
pieces may be done, at once, with comparatively littip
trouble, and the heat is also more equally applied.
A still more accurate method of producing any desired
degree of temper is, to immerse the steel in some fluid
medium, the temperature of which is kept regulated, by
the thermometer. Thus oil, which boils at about six
244 ARTS OF METALLURGY
hundred degrees, may be used, for this purpose, at any
degree of heat which is below that number of degrees.
Mr. Parkes has recommended the employment of metal-
lic baths, chiefly composed of lead and tin, in different
proportions, which pass into fusion, at definite tempera-
tures, and which can be used for tempering steel, as soon
as they arrive at their melting points.* f
* The following table of metallic baths is given, in Parkes's Cheni
ical Essays, Appendix to vol. ii.
No. Edge Tools to be tempered in the various Composition Temper-
Baths. of the Bath. Fahren.
1 Lancets, in a bath, composed of 7 lead 4 tin 420^
2 Other surgical instruments, 7^ lead 4 tin 430
3 Razors, &c., 8 lead 4 tin 442
4 Penknives, gnd some implements of
surgery, 8^ lead 4 tin 450
5 Larger penknives, scalpels, &c., 10 lead 4 tin 470
6 Scissors, shears, garden-hoes, cold
chisels, &c., 14 lead 4 tin 490
7 Axes, firmer chisels, plane-irons,
pocket-knives, &c., 19 lead 4 tin 509
8 Table-knives, large shears, &,c., 30 lead 4 tin 530
9 Swords, watch-springs, &c., 48 lead 4 tin 550
10 Large springs, daggers, augers, small
fine saws, &c., 50 lead 2 tin 558
11 Pit-saws, band-saws, and some par-
ticular springs. Boiling linseed oil 600
12 Articles which require to be still
somewhat softer. Melting lead 612
t Formerly, no man in Great Britain knew how to temper a sword
m such a way, that it would bend, for the point to touch the heel and
spring back again uninjured, except one Andrew Ferrara, who resided
in the Highlands of Scotland. The demand which this man had for hi<
swords was so great, that he employed workmen to forge then), and
spent all his own time in tempering them ; and found it necessary,
even in the day time, to work in a dark cellar, that he might be better
able to observe the progress of the heat, and that the darkness of his
workshop might favor him in the nicety of the operation.
The swords, which were formerly in the highest repute, were made
at Damascus, in Syria. The method, by which these were made, has
long been lost, or perhaps it was never thoroughly known to Europe-
ans ; but from their striated appearance, it has been supposed that
they were formed by alternate layers of extremely thin plates of iron
and steel, bound together with iron wire, and then firmly cemented
together by welding. These weapons never broke, even in the hard-
est conflict, and retained so powerful an edge, as to be capable of cut-
ting through armor. Various other explanations have been given in
regard to the character and structure of the Damascus, or damasked
steel.
CUTLERY. 245
Cutlery. — Under the head of cutlery, are comprehend-
ed numerous instruments, designed for cutting or penetra-
tion, and which are made of steel, mostly, by the proces-
ses of forging, tempering, grinding, and polishing. The
inferior kinds of cutlery are made of bhstered-steel, weld-
ed to iron. Tools of a better quahty are manufactured
from shear-steel, while the sharpest and most dehcate in-
struments are formed of cast-steel.
The first part of the process consists in forging, and is
varied, according to the kind of article to be formed.
Common table-knives ., have the blade forged of steel, and
welded to a piece of iron, out of which the shoulder, and
part which entei*s the handle, are made, the shape being
given to them by hammering in a die and swage. They
are afterwards tempered and ground. Forks are made
by forging the shank, and flattening the other end to the
length intended for the prongs. The prongs are made,
by stamping the metal, at a white heat, between two dies,
the uppermost of which is attached to a heavy weight,
and falls from a height. The shape is thus given to the
fork, leaving, however, a flat thin piece of metal between
the prongs, w^hich is afterwards cut out with a fly-press.
They are subsequently filed, bent, hardened, and pol-
ished.
Blades of penknives are forged from the end of a rod
of steel, and cut qfl*, together with metal enough to form
the joint. The smal! recess, in which the nail is insert-
ed, to open the knife, is made with a curved chisel, while
the steel is hot. Razors are forged from cast-steel,
much in the same manner as knives. The anvil is com-
monly a httle rounded, at the sides, for the purpose ol
making the sides of the razor a little concave, and the
edge thinner. In forging scissors^ the shape is given to
the different parts, by hammering them upon different in-
dented surfaces, called bosses. The bows which receive
the finger and thumb are made, by punching a hole in the
metal, and enlarging it, by hammering it round a tool,
called a beak iron. The halves are finished by filing and
grinding, and afterwards united by a joint. Saws are
made from steel-plates, rolled for the purpose, and have
21*
246 ARTS OF METALLURGY.
their leeth cut and finished by fiHng, and set by a suita-
ble instrument. Axes^ adzes, and other large tools, are
forged from iron, and have a steel piece welded on, of
the proper size, to form the edge.
To enable the steel to be wrought, it is brought to its
softest state ; but after the shape is given to the instrument,
the steel is hardened and tempered, by the methods al-
ready described. The remaining part of the manufacture
consists in grinding, polishing, and setting the instrument,
to produce a smootli surface and a sharp edge. The
grinding is performed upon stones, of various kinds,
among which, freestone is, perhaps, the most common.
These stones are made to revolve by machinery, and
move with prodigious velocity, so that the surface, in
some cases, passes over six or seven hundred feet, in a
second, and stones have been burst by their own centri-
fugal force. For grinding flat surfaces, hke those of
saws, the largest stones are used ; while, for concave
surfaces, hke the sides of razors, smaller stones are used,
on account of their greater convexity. The internal sur-
faces of scissors, forks, &c., which cannot be apphed to
the stone, are ground with sand and emery, applied with
instruments of wood, leather, and other elastic substan-
ces. The last polish is given by the impure oxide of
iron, called colcothar-crocus, and by the French, Rouge
c?' Angleterre. The edges are lastly set with hones and
whetstones, according to the degree of keenness required.
The test, used by cutlers, for determining the goodness
of the edge and point of a lancet, is, that it shall pass
through a piece of soft leather, without sensible resis-
tance. JVeei/esare polished, by tying them in large bun-
dles, with emery and oil, and rolling them under a heavy
plank, till they become smooth, by mutual attrhion. The
shape is previously given, and the eye made with a steel
punch.
A process has been invented by Mr. Lucas, for con-
verting edge-tools, nails, &c., made of cast-iron, into
good steel. It consists in stratifying the cast articles,
in cylindrical metalHc vessels, with native oxide of iron,
and then submitting the whole to a regular heat, in a fur-
ARTS OF VITRIFICATION. 247
nace built for the purpose. It is not, however, necessary
that the oxide employed should be a native oxide, any
artificial oxide being equally efFectual.
The cast-iron, of which this cutlery is made, is brittle,
in the first instance, hke other cast-iron, in consequence
of the carbon contained in it ; but the great heat which it
undergoes, aided by the pulverized oxide, separates a part
of the carbon. This, uniting with the oxygen of the
ground oxide of iron, is dissipated in the state either of
carbonic oxide, or carbonic acid gas, and the articles are*
then converted into a state nearly similar to that of good
cast-steel cutlery. They do not, however, receive so
fine an edge, and do not bear hardening and tempering, in
the common manner.
Works of Reference. — Murray's System of Chemistry, 4
vols. 8vo. 1806 ; — Parkes's Chemical Essays, 2 vols. Svo. 1823 ; —
Gray's Operative Chemist, Svo. 1828 ; — Dumas, Traite de Chi/nie
Appliquee aux Arts, SfC, 4 torn. 8vo. 1828-9 ; — Fourcroy, Sys-
ieme des Connaissances Chimiques, 11 tom. 1801 ; — Aiken's Dic-
tionary of Chemistry and Mineralogy, 2 vols. 4to. 1807 ; — Martin's
Circle of Mechanic Arts, 4to. 1818 ; — Emporium of Arts and Scien-
ces, Philadelphia, 1812-14 ; Franklin Journal, Philadelphia, 1826, and
after ; — Rees' Cyclopedia, various heads ; — Ure's Dictionary of
Chemistry ; — Thenard, Traite de Chimie, 5 tom. Svo. 1824 ; —
Works of Bergman, Klaproth, Lewis, &c. ; — LardnerN
Cabinet Cyclopedia, 3 vols. 12 mo. entitled, Manufactures in Metal
CHAPTER. XXI.
ARTS OF VITRIFICATION.
Glass, Materials, Crown Glass, Fritting, Melting, Blowing, Anneahng,
Broad Glass, Flint Glass, Bottle Glass, Cylinder Glass, Plate Glass,
Moulding, Pressing, Cutting, Stained Glass, Enamelling, Artificial
Gems, Devitrification, Reaumur's Porcelain, Crystallo-Ceramie.
Glass Thread, Remarks.
A GREAT number of earths, and other mineral bodies,
after being fused, do not resume their original character,
upon cooling, but pass into a dense, hard, shining, and
248 ARTS OF VITRIFICATION.
brittle, state, having the character of glass ; and are thus
said to be vitrified. Most of these substances do not
immediately become hard, upon the reduction of their
temperature, but go througa an intermediate, or ductile,
state, in which a combination of softness with tenacity, en-
ables them to be wrought into articles of use and orna-
ment. Of these, common glass is the most important,
while enamels, artificial gems, &c., belong to the same
s})ecies of manufacture.
Glass. — Glass is a compound substance, artificially
produced, by the combination of silicious earth with al-
kalies, and, in some cases, with other metallic oxides.
These substances, being melted together at a high tem-
perature, unite, lose their opacity, and are fused into a
homogeneous mass, which, on cooling, has the. properties
of hardness, transparency, and brittleness.
Materials.* — The most important ingredient, and, in
fact, the basis, of transparent glass, is silica, or oxide of
silicium. This earth, nearly in a state of purity, is found
in the sand of certain situations, and also in common flint,
and quartz pebbles. Sand has the advantage of being
already in a state of minute division, not requiring to be
pulverized. Pure silicious sand, proper for the glass fur-
nace, is found in many localities. A great portion of
that used in the United States is taken from the banks
of the Delaware. When flints, or quartz, are employed,
they must be first reduced to powder, which is done by
heating them red hot, and plunging them in cold water.
This causes them to whiten and fall to pieces ; after which,
they are ground and sifted, before they are ready for the
furnace.
An alkaline substance, either potash or soda, is the
second ingredient in glass. For the finer kinds of glass,
pure pearlash is used, or soda, procured by decomposing
* The term metals^ which appears to be a corruption of materials,
13 in common use, among glass-manufacturers, to express the ingredi-
ents, or substances, upon which their operations are performed. The
same term is employed, in a similar sense, by other manufacturers and
artists, and by some writers on road-making. The term metal, in the
singular, is applied to glass, in a state of fusion
CROWN-GLASS. 249
sea-salt ; but, for the inferior sorts, impure alkalies, and
even wood-ashes, are made to answer the purpose. Lime
is often employed, in small quantities ; also borax, a salt
which facihtates the fusion of the silica.
Instead of the common alkalies, the sulphate of soda
may be employed, in glass-making. But, in this case,
it is necessary to liberate the alkali, by decomposing the
sulphuric acid of the salt. This may be done, by char-
coal, or, in flint-glass, by metallic lead. Lime is also
used with this salt.
Of the metaUic oxides, which are added in different
cases, the deutoxide of lead (red lead) is the most com-
mon. This substance renders flint-glass more fusible,
heavy, and tough, and more easy to be ground and cut.
At the same time, it imparts to it a greater brilliancy, and
refractive power. Black oxide of manganese, in small
quantities, has the effect of cleansing the glass, or of ren-
dering it more colorless and transparent. This effect it
seems to produce, by imparting oxygen to the carbona-
ceous impurities, thus forming with them carbonic acid,
which subsequently escapes. Common nitre produces a
similar effect. If too much manganese be added, it com-
municates a purple tinge to the glass, which, however,
may be destroyed, by a little charcoal or wood. Arsen-
ious acid, (white arsenic,) in small quantities, promotes
the clearness of glass ; but, if too much be used, it com-
municates a milky whiteness. Its use, in drinking-ves-
sels, is not free from danger, when the glass contains
so much alkali, as to render any part of it soluble in
acids.
Crown Glass. — Glass is of various kinds, which are
named, not only from the character of their ingredients,
but from the mode in which they are wrought. The name
of croicn-glass is given to the best kind of window-glass,
that which is hardest, and most free from color. It is
made almost entirely of sand and alkali, and a litde lime,
without lead, or any other metallic oxide, except a minute
quantity of manganese, and sometimes of cobalt, which are
added, to counteract the effect of any impurities, in giving
color to the glass. Crown-glass requires a 2;reatpr heat,
250 ARTS OF VITRIFICATION.
to melt its ingredients, than those kinds, which contain a
larger quantity of metaUic oxide, especially of lead.
Frilting, — After the materials have been intimately
mixed, they are subjected to the operation, called/n/^i?i^.
This consists in exposing them to a dull, red heat, which
is not sufficient to produce their fusion. The use of this
process is, to drive off the carbonic acid, and other gase-
ous and volatile matters, which would otherwise prove
troublesome, by causing the materials to swell up in the
glass-pots. The heat is gradually increased, and the ma-
terials constantly stirred, for some hours, until they unite
into a soft, adhesive mass ; the alkali having gradually
combined with the silicious earth. The reason why the
fritting is conducted at a low heat is, that, if a high tem-
perature were applied, at once, the alkali would be driven
off, before it had time to combine with the silica.
Melting. — The homogeneous mass, or frit^ is next
transferred to the glass-pots of the melting furnace. These
are crucibles, made of the most refractory clays and sand.
A quantity of old glass is commonly placed upon the
top of the frit, and the heat of the furnace is raised to
its greatest height, at which state it is continued for thirty
or forty hours. During this time, the materials become
perfectly united, and form a transparent, uniform, mass,
free from specks and bubbles. The whole is then suf-
fered to cool a little, by slackening the heat of the fur-
nace, until it acquires sufficient tenacity to be wrought.
Blowing. — The formation of window-glass is effected,
by blowing the melted matter, or metal., as it is called,
jnto hollow spheres, which are afterwards made to ex-
pand into circular sheets. The workman is provided
with a long, iron tube, one end of which he thrusts into
the melted glass, turning it round, until a certain quantity,
sufficient for the purpose, is gathered.^ or adheres to the
extremity. The tube is then withdrawn from the furnace,
the lump of glass, which adheres, is rolled upon a smooth
iron table, and the workman blows strongly, with his
mouth, through the tube. The glass, in consequence of
its ductility, is gradually inflated, like a bladder, and is
prevented from falling off, by a rotary motion, constantly
ANNEALING. BROAD-GLASS. 251
communicated to the tube. The mflation is assisted by
the heat, which causes the air and moisture of the breath
to expand, with great power. Whenever the glass be-
comes so stiff, from coohng, as to render the inflation
difficuh, it is again held over the fire to soften it, and the
blowing is repeated, until the globe is expanded to the
requisite thinness. It is then received, by another work-
n'jr.n, upon an iron rod,* while the blowing-iron is detach-
ed. It is now opened at its extremity, and, by means of
the centrifugal force, acquired from its rapid whirling, it
spreads into a smooth, uniform sheet, of equal thickness
throughout, excepting a prominence at the centre, where
the iron rod was attached.
Annealing. — After the glass has received the shape
which it is to retain, it is transferred to a hot chamber, or
annealing furnace, in which its temperature is gradually
reduced, until it becomes cold. This process is indis-
pensable to the durability of glass ; for, if it is cooled too
suddenly, it becomes extremely brittle, and flies to pieces,
upon the slightest touch of any hard substance. This
effect is shown^n the substances called Rupert's-drops,
which are made, by suddenly cooHug drops of green glass,
by letting them fall into cold water. These drops fly to
pieces, with an explosion, whenever their smaller extrem-
ity is broken off. The BGlogna-phials, and some other
vessels of unannealed glass, break into a thousand pieces,
if a flint, or other hard and angular substance, is dropped
Into M^em. This phenomenon seems to depend upon
some permanent and strong inequality of pressure ; for
when these drops are heated so red as to be soft, and
left to cool, gradually, the property of bursting is lost, and
the specific gravity of the drop is increased.
Broad Glass. — This is a coarser kind of window-glass,
and is made from sand, with kelp and soap-boilers' waste
It is blo\\Ti into hollow cones, about a foot in diameter,
and these, while hot, are touched on one side with a cold
iron, dipped in water. This produces a crack, which
runs through the length of the cone, nearly in a right line
* Called a punt, or punting-iron.
252 ARTS OF VITRIFICATION.
The glass then expands into a sheet, in its form resemb-
ling, somewhat, the shape of a fan. This appears to have
been one of the oldest methods of manufacturing glass.
Flint Glass. — Flint-glass, so called, from its having
been originally made of pulverized flints, differs from win-
dow-glass, in containing a large quantity of the red oxide
of lead. The proportions of its materials differ ; but, in
round numbers, it consists of about three parts of fine
sand, two of red lead, and one of pearlash, with small
quantities of nitre, arsenic, and manganese. It fuses at a
lower temperature than crown-glass, has a beautiful trans-
parency, a great refractive power, and a comparative soft-
ness, which enables it to be cut and polished, with ease.
On this account, it is much used for glass vessels, of every
description, and especially those which are intended to be
ornamented, by cutting. It is also employed for lenses,
and other optical glasses. Flint-glass is worked, by blow-
ing, moulding, pressing, and grinding. Articles of com-
plex form, such as lamps and wine-glasses, are formed
in pieces, which are afterwards joined, by simple contact,
while the glass is hot. It appeal's, that the red lead, used
in the manufacture of flint-glass, gives up a part of its oxy-
gen, and passes to the state of a protoxide.
Bottle Glass. — Common green glass, of which bottles
are made, is the cheapest kind, and formed of the most
ordinary materials. It is composed of sand, with lime,
and sometimes clay, and alkaline ashes, of any kind, such
as kelp, barilla, or even wood-ashes. The green color
is owing to the impurities in the ashes, but chief!}', to
oxide of iron. This glass is hard, strong, and well vitri-
fied. It is less subject to corrosion, by strong acids, than
flint-glass ; and is superior to any cheap material, for the
purposes to which it is ordinarily applied.
Cylinder Glass. — The plates of crown-glass, which
^re obtained in the common manner, by blowing them in
circular plates, afford the common material for window-
glass ; being cut into squares, by first marking the surface
deeply, with a diamond, and then breaking the glass, m
the same directions ; the crack always following the exact
course of the incision, made by the diamond. But there
PLATE-GLASS. 253
is always a loss, or waste, in cutting squares, from a cir~
cular plate ; besides which, they can never be very large,
owing to the protuberance, or bulVs-eye, which fills the
centre of the plate ; so that a square can never be larger,
than can be described within less than half the circle.
To remedy this disadvantage, plates for looking-glasses,
and others, of large size, are executed in a different way,
either by blowing them in cyhnders, or by casting them
in plates, at first.
Cyhnder glass is blown, at first, in spheres, like window-
glass. These are elongated into spheroids, by a swinging
motion, which the workman gives to his rod. The ends
of this spheroid are successively perforated, thus conver-
ting it into an irregular cylinder. One side of this cylinder
is cut through, with shears, and the glass is laid upon a
flat surface, where it expands into a uniform plate, with-
out any protuberance. It is then annealed, by diminishing
the heat, in the common way. When the plates are in-
tended for looking-glasses, the finest materials are used,
and the heat kept at its greatest height, for a long time,
to dissipate all impurities, and remove any specks or bub-
bles.
Plate Glass. — Looking-glass plates may be blown in
cyhnders, when they do not exceed about four feet in
length. But they cannot well be blown, of a larger size
than this, from such a quantity of glass as the rod will
take up, without becoming too thin to bear pohshing.
Plates, however, may be made of more than double this
size, by another process, which is called casting, and
which is the only mode by which very large plates are
produced.
When glass is to be cast, it is melted, in great quanti-
ties, in large pots, or reservoirs, until it is in a state of
perfect fusion, in which state it is kept for a long time.
It is then drawn out, by means of iron cisterns, of consid-
erable size, which are lowered into the furnace, filled, and
raised out, by machinery. The glass is poured out from
these cisterns, upon tables of polished copper, of a large
size, having a rim elevated as high as the intended thick-
ness of the plate. In order to spread it perfectly, and tc
II. 22 . XII.
254 ARTS OF VITRIFICATION.
iniike the two surfaces parallel, a heavy roller of polished
copper, weighing five hundred pounds, or more, is rolled
over the plate, resting upon the rim, at the edges. The
glass, which is beginning to grow stift\ is pressed down,
and spread equally, the excess being driven before the rol-
ler, till it falls oft' at the extremity of the table. The plate
is then ready to be annealed.
As the plates, which are cast for looking-glasses, are
always uneven and dull, at their surface, it is necessary
to grind and polish them, before they are fit for use.
The process, employed for producing a perfectly even
and smooth surface, is very similar to that employed in
polishing marble ; except that the glass, being the harder
substance,- requires more labor and nicety, in the oper-
ation. The plate to be polished is first cemented to a
table of wood or stone, vv'ith plaster of Paris. A quan-
tity of wet sand or emery is spread upon it, and anoth-
er glass plate, similarly cemented to another wooden sur-
face, is brought in contact with it. The two plates are
then rubbed together, until the surfaces have become mu-
tually smooth and plane. The emery, which is first used,
is succeeded by emery of a finer grain, and the last polish
is given by colcothar or putty. When one surface has
become perfectly polished, the cement is removed, the
plate turned, and the opposite side pohshed in the same
manner.
As the grinding of glass causes an expenditure of a
considerable portion of its substance, a great waste of
glass takes place, when foreign materials are employed,
in the manner which has been described. To prevent
this loss, a more economical mode has been introduced,
in which the glass is ground with pure flint, reduced to
powder. The mixture of glass and flint, which is left,
after the operation, is valuable, for forming fresh glass.
JMoulding. — A variety of ornamental forms are pro-
duced, upon the surface of glass vessels, by impressions
given to them with a metallic mould, while the glass is in
a hot state. Flint-glass is the kind which is used for
articles, intended to possess much brilliancy ; but coarser
kinds, even of colored glass, are also subjected to the
PRESSING. CUTTING. 255
same process. The simplest manner, in which the ope-
ration is conducted, consists, in blowing the glass into the
mould, till it receives the impression, on its outside. For
this purpose, a quantity of glass, sufBcient to form the
intended vessel, is taken up on the end of a pipe, and in-
serted at the top of the mould. The workman then blows,
with his mouth, till a hollow portion of glass is driven into
the mould, and expands, so as to fill every part, and re-
ceive an impression on its outside. The mould is usual-
ly made of copper, with the figure cut on its inside, and
opens with hinges, to permit the glass to be inserted, and
taken out. As the mould is, of necessity, much cold-
er than the glass, the latter substance is chilled, at its
surface, as soon as it comes in contact with the cop-
per ; hence its ductility is impaired, and the impression
given is never so sharp as that w^iich is obtained with
substances, which are nearly at the same temperatures.
Moulded bottles, phials, decanters, &c., are made in this
way.
Pressing. — An improvement has been made, in the
process of moulding glass, by subjecting the material to
pressure, on the inside and outside, at the same time, by
different parts of a mould, which are brought suddenly
together, by mechanical power. This process has been
carried to great perfection, in several of the manufacto-
ries in this country,* and produces specimens, which
compare with cut glass, in the accuracy and beauty of
the workmanship. It is applied only to solid articles,
and to vessels which are not contracted at top. The
hot glass being dropped into the mould, a part, called the
follower, answering to the inside or top of the vessel, or
other article,_is immediately pressed down upon it, by a
lever, and the glass is thus stamped with a very distinct
impression of the figure, on both sides at once. The
glass vessel is sometimes transferred from the mould to
another receptacle, called the receiver, in order to pre-
serve its shape, till it is cool enough to stand.
Cutting. — The name of cut-glass is given, in com
* Particularly, at Lee Anere's Point, and Sandwich
256 ARTS OF VITRIFICATION.
merce, to glass which is ground and polished, in figures,
with smooth surfaces, appearing as if cut by incisions of
a sharp instrument. This operation is chiefly confined
to flint-glass, which, being more tough, soft, and brilliant,
than the other kinds, is more easily WTOught, and pro-
duces specimens of greater lustre. An establishment for
cutting glass, contains a great number of small wheels, of
stone, metal, and wood, which are made to rev^olve rap-
idly, by a steam-engine or other power. The cutting
of the glass consists entirely, in grinding away successive
portions, by holding them upon the surface of these wheels.
The first, or rough cutting, is sometimes given by wheels
of stone, resembling grindstones. Afterwards, wheels
of iron are used, having their edges covered with sharp
sand, or with emery, in different states of fineness. The
last polish is given by brush-wheels, covered with putty,
which is an oxide of tin and lead. To prevent the fric-
tion from exciting so much heat, as to endanger the glass
a small stream of water continually drops upon the sui
face of the wheel.
Stained Glass. — The name of staining has been ap
plied to the process, by which painting, with vitrifiable
colors, is executed upon the surface of glass. The pig-
ments used are, chiefly, metallic oxides, which do not ex-
hibit their full color, until they have been exposed to the
heat of the furnace. This art has been repeatedly des-
cribed, as being no longer known ; but this is not the
fact, except in respect to some particular colors, which
are found in the windows of the ancient cathedrals.
The metallic oxides, used in staining glass, are difficult
of fusion ; on which account, it is necessary to mix them
with a flux, composed of glass, with lead or borax. This
renders the oxide fusible, at a temperature which does
not injure its color ; also, by enveloping the particles, it
causes them to adhere to the glass, and afterwards pro-
tects them from the atmosphere.
A very beautiful violet, but liable to turn blue, is made
from a flux, composed of borax and flint-glass, colored
with one sixth part of the purple of Cassius^ precipitated
from muriate of gold, by protomuriite of tin.
ENAMELLING. 257
A fine red is made from red oxide of iron, prepared by
nitric acid and heat, mixed with a flux of borax, and a
small proportion of red lead.
A yellow, equal in beauty to that produced by the an-
cients, may be made from muriate of silver, oxide of
zinc, white clay, and the yellow oxide of iron, mixed to-
gether, without any flux. A powder remains on the sur-
iace, after the glass has been baked ; but this is easily
cleaned off.
Blue is produced by oxide of cobalt, with a flux, com-
posed of fine sand, purified pearlash, and red lead.
Black is produced, by mixing the composition for blue,
with the oxides of manganese and iron.
ToiStain glass green, it may be painted blue, on one
side, and yellow^, on the other.
The colors, ground with water, being laid upon the
glass, must be exposed to heat, under a mufile, so as to
be heated equally, until the color is melted upon the sur-
face. To prevent the panes of glass from bending, they
are placed upon a bed of bone-ashes, of quicklime, or of
unglazed porcelain. A bed of gypsum has been recom-
mended ; but the sulphuric acid, exhaling fron^j^ it, is apt
to injure the glass.
Among ancient specimens of painted glass, some pieces
have been found, in which the colors penetrate through
the glass, so that the figure appears in any section, made
parallel to the surface. It is supposed, that such pieces
can only have been made in the manner of mosaic, by ac-
cumulating transverse filaments of glass, of different col-
ors, and uniting them by heat, 'the process being one of
great labor. They are described by Winckelmann, and
Caylus, from some specimens brought from Rome.
Enamelling. — Enamels are compositions of various
substances, which, when vitrified upon the surface of
opaque bodies, communicate their colors, and produce
the effect of painting. Enamels differ from stained glass,
as a common picture differs from a transparency ; the
former producing its effect, when viewed by reflected,
and the latter by transmitted, light. Enamels are exe-
cuted upon the surface of copper, and other metals, bv
22*
258 ARTS OF vitrificatAn.
a method, similar to painting. One coat, or color, often
requires to be vitrified, before another is laid upon it ;
and thus the plate, to be enamelled, is obliged to be ex-
posed to heat, several successive times.
Transparent enamels are usually rendered opaque, by
adding putty, or the white oxide of tin, to them. The
basis of all enamels is, therefore, a transparent and fusi-
ble glass. The oxide of tin renders this of a beautiful
white, the perfection of which is greater, when a small
quantity of manganese is likewise added. If the oxide
of tin be not sufficient to destroy the transparency of the
mixture, it produces a semi-opaque glass, resembling the
opal.
The metals, employed as coloring materials, are, 1.
Gold. The purple of Cassius imparts a fine ruby tint.
2. Silver. Oxide, or phosphate, of silver, gives a yellow
color. 3. Iron. The oxides of iron produce green, yel-
low, and brown, depending upon the state of oxidizement,
and quantity. 4. Copper. The oxides of copper give a
rich green ; they also produce a red, when mixed with
a small proportion of tartar, which tends, partially, to re-
duce the» oxide. 5. Antimony imparts a rich yellow.
6. Manganese. The black oxide of this metal, in large
quantities, forms a black glass ; in smaller quantities, vari-
ous shades of purple. 7. Cobalt, in the state of oxide,
gives beautiful blues, of various shades ; and, with the yel-
low of antimony, or lead, it produces green. 8. Chrome
produces fine greens and reds, depending upon its state of
oxidizement.
Artificial Gems. — The great value of the precious
stones has led to artificial imitations of their color and
lustre, by compositions in glass. In order to approximate,
as near as possible, to the briUiancy, and refractive power,
of native gems, a basis, called a paste, is made from the
finest flint-glass, composed of selected materials, combin-
ed, in different proportions, according to the preference
of the manufacturer. This is mixed with metallic oxides,
capable of producing the desired color. A great num-
ber of complex recipes are in use, among manufacturers
of these articles.
DEVITRIFICATION. REAUMUR's PORCELAIN. 259
Devitrification. — It is found, that, if certain kinds of
glass be exposed to heat, sufficient to keep them in a soft
state, for some hours, and are suffered to cool, gradually,
they lose their transparency, and pass into the state of an
opaque substance, of a grayish white color. M. Dartri-
gues,* who has examined the cause of this change, as-
serts, that it is owing to a real crystallization of the vitreous
siHcate. Common bottle-glass is most easily changed, in
this manner ; while those varieties, which contain neither
lime, nor alumina, are the most difficult to devitrify. In
all cases, glass, which has undergone this change, requires
a stronger heat to melt it, than before.
Reaumur^s Porcelain. — It has been frequently observ-
ed, that, during the anneahng of green glass, some parts of
it become white, and opaque. M. Reaumur made experi-
ments on this apparent devitrification of glass, and found
it was owing to the alkali flying off, by the too long con-
tinuance, or too great degree, of the heat, and that the
opaque, changed glass, had acquired the quality of bear-
ing sudden transitions of heat and cold, as well as the
best porcelain.
For the purpose of making vessels, of this kind, com-
mon bottle-glass is chosen, and blown into the proper
form. The vessfel is then to be filled to the top, with a
mixture of white sand and gypsum, and is set in a large
crucible, upon a quantity of the same mixture, with which
the glass vessels must also be surrounded, and covered
over, and the whole pressed down, rather hard. The
crucible is then to be covered with a Hd, the junctures
well luted, and put into a potter's kiln, where it remains,
during the whole time that the pottery is baking ; after
which, the glass will be found changed into a milk-white
porcelain.
An imitation of porcelain, which is lately introduced
into our shops, and which combines whiteness with a
beautiful semi-transparency, is made of flint-glass, con-
taining a portion of white arsenic, on which its opacity
depends.
♦Journal de Physique, 1804.— Thenard, Chimie, ii. 473
260 ARTS OF VITRIFICATION.
Crystallo Ceramie. — This name is given loan elegant)
but difficult, species of manufacture, in which medallions,
portraits, and other subjects, executed in an opaque mate-
rial, are enclosed, or encrusted, with glass. This art was
first attempted, by enclosing, in glass, smafi figures, made
of a peculiar kind of clay ; but these experiments were
only in few instances successful, owing to the unequal ex-
pansion and contraction of the two substances, and theii
consequent fracture. More recently, a composition has
been employed, for the opaque figure, which is less liable
to these accidents. It is necessary, that the substance,
employed in these devices, should be less fusible than
glass, incapable of generating air, and, at the same time,
susceptible of expansion and contraction, as the glass
becomes hot or cold. The ornamental figures are intro-
duced into the glass while hot, and thus become incorpor-
ated with it.
Glass Thread. — The great ductility of glass is one
of its most remarkable properties. When heated to a
sufficient degree, i't may not only be moulded, into any
possible form, with the utmost facility, but it can be drawn
out into the finest fibres. The method of spinning glass
is very simple. The operator holds a piece of glass over
the flame of a lamp, w^ith one hand ; he then fixes a hook
to the melted mass, and, by withdrawing it, obtains a thread
of glass, attached to the hook. The hook is then fixed in
the circumference of a cylindrical drum, which can be
turned round by the hand ; and a rapid, rotary motion
being given to the drum, the glass is drawn in the finest
threads, from the fluid mass, and coiled round the cylin-
drical circumference. M. Reaumur supposed, with great
reason, that the flexibility of glass increased with the fine-
ness of the threads, and he therefore conjectured, that, if
they were drawn to a sufficient degree of fineness, they
might be used in the fabrication of stufl^s. He succeeded
in making them as fine as a spider's web ; but he was nev-
er able to obtain them of a sufficient length, when their di-
ameter was so much reduced. The circumference of
these threads is generally a flat oval, about three or four
times as broad as it is thick. By using opaque and
REMARKS 261
transparent glass, of different colors, artists have been
able to produce many beautiful ornaments. M. Bonnet,
and others, have succeeded in obtaining glass fibres, of
such fineness and flexibility, af to admit of being woven
into cloth, of a very brilliant, silvery appearance.
Remarks. — Pure glass possesses the remarkable prop-
erty, of sufi:ering no change by the application of an intense
heat. The effect of great heats is only to melt the glass,
or to dissipate it in vapor ; but, as long as any of the glass
remains, it still preserves its transparency, and other dis-
tinguishing properties.
Of all the solid substances, whose expansibility has
been accurately examined, glass possesses the property
of being least affected by heat or cold. Its expansion,
according to General Roy, with an increase of heat, equal
to one hundred and eighty degrees of Fahrenheit's
thermometer, is only 0.000776, while that of platina is
0.000S56, and that of hammered zinc, 0.003011. On
account of this property, glass is peculiarly fitted for con-
taining fluids, whose expansions are under examination, as
its own change of form may, in ordinary cases, be neglec-
ted. For the same reason^ it is better than any other
substance, for the simple pendulum of a clock.
The invention of glass seems to have been extremely
ancient, and some curious specimens are found, in the sar-
cophagi of Egyptian mummies. Glass windows appear
not to have been in use, among the Romans of the Augus-
tan age ; though vessels and plates of glass are found at
Herculaneum, and Pompeii. Most of the important im-
provements, in the manufacture of this substance, have
been made by the moderns.
W^RKs OF Reference. — Parkes's Chemical Essays, 8vo. voL
ii.; — LoYSEL, Essai sur VArt de la Verrerie, 8\'o. 1800; — Brog-
NiART, Art de V Emailleur, Annales de Chimie, torn. ix. and other
works ; — Franklin Journal, v. 80 ; — Article Glass in Rees' Cyclope-
dia, and in the Edinburgh Encyclopedia ; — Lardxer's Cabinet Cy-
clopedia, 12mo. vol. xxvi ; — Chaptal, Chimie Appliquee aux Arts,
4 vols. 8vo. 1806 ; — Gray's Operative Chemist, 8vo. 1828; — Thex-
ARD, Traite de Chimie, vol. ii. ; — Brande's Chemistry ; — Beck-
man's History of Inventions, 4 Tols. 8vo. translated 1797; — Works of
Neri, Blancourt, Kunckbi., Reaumur, &c.
262 ARTS OF INDURATION BY HEAT.
CHAPTER XXII.
ARTS OF INDURATION BY HEAT.
Brickrf, Pressed Bricks, Tiles, Terra Cotta, Crucibles, Pottery, Opera-
tions, Stone Ware, White Ware, Throwing, Pressing, Casting,
Burning, Printing, Glazing, China Ware, European Porcelain,
Etruscan Vases.
Common clay, with its varieties, consisting essentially
of alumina and silica, also, the artificial imitations of clay,
into which these earths enter, possess properties, adapted
to render them highly useful in the arts. When mixed
with water, they form a ductile and tenacious paste, ca-
pable of being moulded into various forms, and of acquir-
ing, when exposed to the heat of a furnace, a durable
and stony hardness. These compounds are used in dif-
ferent states, to form the materials, both for the largest
structures, and the most delicate ornaments ; and they
are surpassed by few substances, in the power of resisting
the effects of exposure and time. Bricks, tiles, terra-
cotta, pottery, and porcelain, are the most noticeable pro-
ducts of the branch of industry, in the operations of which
indurated \:lay is the material."
Bricks. — The use of bricks, in building, may be traced
to the earhest ages, and they are found among the ruin-
of almost every ancient nation. The walls of Babylon,
some of the ancient structures of Egypt, and Persia, the
walls of Athens, the Rotunda of the Pantheon, the Tem-
ple of Peace, and the Thermae, at Rome, were all of brick.
The earliest bricks were dried in the sun, and were never
exposed to great heat, as appears from the fact, that thev
contain reeds and straws, upon which no mark of burning
is visible. These bricks owe their preserviation to the
extreme dryness of the climate, in which they have re-
mained ; since the earth, of which they are made, often
crumbles to pieces, when immersed in water, after having
kept its shape for more than two thousand years. This
PRESSED BRICKS. 263
is the case, with some of the Babylonian bricks, with in-
scriptions in the arrow-headed character, which have been
brought to this country. The ancients, however, at a later
period, burnt their bricks ; and it is these, chiefly, which
remain at the present day. The antique bricks were
larger than those employed by the moderns, and were al-
most universally of a square form. Besides bricks made
of clay, the ancients also employed a kind of factitious
stone, composed of a calcareous mortar.*
Modern bricks receive their hardness from exposure to
heat, in the process of burning. The common clay, of
which they are made, consists of a mixture of argillaceous
earth, and sand. Most of our common clays contain, also,
oxide of iron, which causes the bricks to turn red, in burn-
ing, l^ure clays become white in the furnace, such as
that of which pipes are made, and common crockery-ware.
Clay, after it is taken from the earth, requires to be
thoroughly mixed, incorporated, and mellowed, before it
is fit for the manufacture of bricks. For this purpose, a
is to be dug in the summer, or autumn, and exposed to the
influence of the frost, through the winter. It should be
worked over repeatedly, whh the spade, and not made into
bricks, till the ensuing spring, previously to which, it is
well tempered, either by treading it, with oxen, or by a
horse-mill, till it is reduced to a tough, homogeneous
paste. In proportion to the labor bestowed on this pro-
cess, the bricks become solid, hard, and strong. The
clay, after being thus prepared, is forced into moulds, to re-
ceive the shape of bricks, and afterwards dried in the sun.
Pressed bricks^ which are used to form the facing of
walls, in the better kinds of structures, are finished in a
machine. The roughness, and change of form, to which
common bricks are liable, is owing, in part, to the evap-
oration of a portion of the water, which the clay contains.
To remedy the difiiculty, arising from this cause, the
bricks, after being moulded, in the common manner,
are exposed to the sun, till they are nearly dried ; retain-
ing, however, sufficient plasticity, to be still capable of a
*Some travellers have even advanced an opinion, that the Py amijg
of Egypt are constructed with an artificial stone.
264 ARTS OF INDURATION BY HEAT.
slight change of form. In this state, they are placed in
an iron mould, and subjected to a strong pressure, by
which they become regular in shape, and very smooth.
A machine usually contains a number of moulds, arranged
in a circle, or otherwise ; so that the power is applied to
them in succession, and the bricks pressed with rapidity.
The burning of bricks is commonly performed, in this
country, by forming them into large, square piles, de-
nominated clamps, or, with us, kilns, having flues, or
cavities, at the bottom, for the insertion of the fuel, and
interstices between the bricks, for the fire and hot air to
penetrate. A fire is kindled in these cavities, and grad-
ually increased, for the first twelve hours, after which, it
is kept up, at a uniform height, for several days and
nights, till the bricks are sufiiciently burned. Much care
and experience are necessary, in regulating the fire, since
too much heat vitrifies them, and too little, leaves them
soft and friable. In some places, the burning of bricks
is conducted in permanent kilns, erected for the purpose.
Tiles. — Tiles are plates ofburnt clay, resembling bricks,
in their composition and manufacture, and used for the
covering of roofs. They are necessarily made thicker
than slates or shingles, and thus impose a greater weight
upon the roofs. Their tendency to absorb water pro-
motes the decay of the wood-work beneath them. Tiles
are usually shaped in such a manner, that the edge of
one tile receives the edge of that next to it, so that water
cannot percolate between them.* Tiles, both of burnt
clay, and marble, were used by the ancients ; and the for-
mer continue to be employed in various parts of Europe.
Floors, made of flat tiles, are used in many countries,
particularly in Italy.
Terra Cotta. — The Italian name, terra-cotta, in French,
terre-cuite, in its most general sense, implies clay, in-
durated by heat. In the arts, however, its use seems to
be restricted to the finer clays, in which ornamental de-
signs have been executed, both by the ancients and mod-
erns. Not only vases, but imhations of sculpture, and
* For different forms of tiles, used at Florence, Trieste, &c., see
Cadoll's Journey in Italy, and Carniola, Plate X.
CRUCIBLES. POTTERY. 205
architectural decorations, are successfully made, froir
this material. Among other things, a complete restoia-
tion of the Choragic monument of Lysicrates, at Athens,
has been made from terra-cotta, in the court of the Lou
vre, at Paris. From the facihty with which it is mould-
ed into any form, this substance would be of great use in
architecture, were it not for the unequal shrinking of the
clay, from heat, and the difficulty of preserving, accurate-
ly, the original proportions.
Crucibles. — Crucibles, melting-pots, and other vessels,
intended for use in the furnace, require to be made of
substances, which sustain a high temperature, without
fusion. When they are made of about one part of pure
clay, mixed with three of sand, and slowly dried, and
annealed, they are found to bear a great heat, and will re-
tain mo^t of the metals which are melted for use in the
arts. Such crucibles, however, are hable to be acted
upon and destroyed, at high temperatures, if the metals
are suffered to become oxidized, or if saline fluxes are
used. To prevent this accident, some crucibles are
made entirely of clay, which is burnt, coarsely powdered,
and mixed with fresh clay. These are found very re-
fractory in the furnace. Crucibles are also made of plain
Stourbridge clay, of Wedgewood's ware, of graphite, and
of platina.
Pottery. — In manufactures of vessels, from argilla-
ceous compounds, the different degrees of beauty, and
costliness, depend upon the quahty of the raw material
used, and upon the labor and skill, expended in the op-
eration. The cheapest products of the art, are those
made of common clay, similar to that of which bricks are
formed, and which, from the iron it contains, usually turns
red, in burning. Next to this, is the common crockery-
ware, formed of the purer and whiter clays, in which
iron exists, only in minute quantities. Porcelain, which
is the most beautiful and expensive of all, is formed
only from argillaceous minerals, of extreme dehcacy,
united with sihcious earths, capable of communicating to
them a semi-transparency, by means of its vitrification.
Clay, although it is a compound body, and possesses
II. 23 XII.
266 ARTS OF INDURATION BY HEAT.
more silica than alumina, neverlneless, derives character?
from the latter, which abundantly distinguish it from mm-
erals, which are more purely silicious. The processes of
its manufacture are, in most respects, the reverse of those
applied to glass, that substance being softened by heat,
and wrought at a high temperature, whereas, the clay 's
wrought while cold, and afterwards hardened by heat.
Operations. — Though the various kinds of pottery
and porcelain differ from each other, in the details of
their manufacture, yet there are certain general principles,
and processes, which are common to them all. The first
belongs to the preparation of the clay, and consists in di-
viding and washing it, till it acquires the requisite fine-
ness. The quahty of the clay requires the intermixture
of a certain proportion of sihcious earth, the effect of
which is to increase its firmness, and render it less hable
to shrink and crack, on exposure to heat. In common
clay, a sufficient quantity of sand exists, in a state oi
natural mixture, to answer this purpose. But in the finer
kinds, an artificial admixture of silica is necessary. The
paste, which is thus formed, is thoroughly beaten and
kneaded, to render it ductile, and to drive out the air.
It is then ready to receive its form. The form of the
vessel, intended to be made, is given to the clay, either
by turning it on a wheel, or by casting it in a mould.
When dry, it is transferred to the oven, or furnace, and
there burnt, till it acquires a sufficient degree of hardness,
for use. Since, however, the clay is still porous, and,
of course, penetrable to water, it is necessary to glaze it.
This is done, by covering the surface with some vitrifiable
substance, and exposing it, a second time, to heat, until
this substance is converted into a coating of glass.
In the coarse earthen ware, which is made of common
clay, the clay, after being mixed and kneaded, until it
has acquired the proper ductility, is transferred to a sort
of revolving table, called the wheel. A piece of clay, of
sufficient size, being placed liTthe centre of this table, a
rotary motion is communicated to it, by the feet. The
potter then begins to shape it, with his hands, which are
previously wet, to prevent its adhering to the fingers
STONE-WARE. WHITE-WARE. 267
The rotary motion gives it a circular form, and it is
gradually wrought up to the intended shape, a tool being
occasionally used, to assist the finishing. The vessels
are now set aside, to dry ; after which, they are baked
in the oven, or kiln. The glazing, of this kind of pottery,
is given by metallic oxides, which vitrify at a low heat.
A yellow glazing is communicated, by the oxide of lead ;
black, by the oxide of manganese ; and white, by the
oxide of tin. Unglazed ware is porous, and permeable
to water, as is seen in common flower-pots, and coolers.
Stone Ware. — The kinds of pottery, denominated
stone-ware, may be formed of the clays, which are used
for other vessels, by applying to them a much greater
degree of heat, the effect of which is, to increase, very
much, their strength and solidity. These vessels do iiot
require to be glazed, with any metallic oxides, but afibrd
the material of their own glazing, by a vitrification of their
surface. When the furnace, in which they are burnt, has
arrived at its greatest heat, a quantity of muriate of soda,
or common salt, is thrown into the body of the kiln.
The salt rises in vapor, and envelopes the hot ware, and,
by the combination of its alkali with the silicious particles
on the surface of the ware, a perfect vitrification is pro-
duced. This glazing, consisting of an earthy glass, is in-
soluble in most chemical agents, and is free from the ob-
jections, to which vessels, glazed with lead, are liable,
that of communicating an unwholesome quality to liquids
contained in them, by the solution of the lead in common
acids, which they frequently contain.
White Ware. — The better sorts of earthen ware are
made of white clay, or of clay containing so little oxide
of iron, that it does not turn red in burning, but, on the
contrary, improves its whiteness in the furnace. This
kind, commonly called pipe clay, is found very pure in
Devonshire, and Dorsetshire, in England. In the manu-
factory of Mr. Wedgewood, to whose industry and in-
genuity the pubHc are indebted, for some of the finest
specimens of the art, the clay is prepared, by first bring-
ing it to a state of minute division, by the aid of machine-
ry. This machinery consists of a series of iron blades,
268 ARTS OF INDURATION BY HEAT.
or knives, fixed to an upright axis, and made to revolve
in a cylinder, and intersecting, or passing between, anoth-
er set of blades, which are fixed to the cylinder. The
clay, by the continual intersection of these blades, is
minutely divided, and, when sufficiently fine, is transferred
to a vat. It is here agitated, with water, until it assumes
the consistence of a pulp, so thin, that the coarser or
stony particles can subside to the bottom, after a little
rest, while the finer clay remains in suspension. This
last is poured ofi:', and suffered to subside, after which it
is passed through sieves, of different fineness, and be-
comes sufficiently attenuated for use.
To this clay is added a certain quantity of flint, re-
duced to powder, by heating it red hot, and throwing it
into cold water, to diminish the cohesion of its parts.
Afterwards, it is pounded by machinery, ground in a mill,
sifted, and washed, precisely as the clay is treated, and
made into a similar pulp. In this state, the two ingredi-
ents are intimately mixed together, in such quantities,
that the clay bears to the flint the proportion of about
five to one.
The object of adding flint to the clay is two-fold. It
lessens the shrinking of the clay, in the fire, and thus ren-
ders it less liable to warp and crack, in the burning. At
the same time, by its partial fusion, it communicates to
the ware that beautiful translucency, which is so much
admired in porcelain, and of which the simple clay-wares
are destitute.
The fine pulp of flint and clay, being intimately mixed,
is then exposed to evaporation, by a gentle heat, until
the superfluous water- is dissipated, and the mass reduced
to a proper consistency to work. To produce a unifor-
mity, in the thickness of the material, it is taken out, in
successive pieces, which are repeatedly divided, struck,
and pressed together, till every part becomes blended with
the rest.
Throioing. — The formation of circular vessels is done
by the process called throwing, performed on the potter's
wheel, in the manner already described ; except that, in
large manufactories, the wheel is not turned by the oper-
PRESSING. CASTING. BURNING. 269
ator himself, but by an assistant, or a steam-engine. The
handles, and similar appendages, are made, by forcing
the clay with a piston, through an aperture, of the size
and shape which it is desired to produce. When formed,
the handles are cemented to the ware, by a thin mixture
of the clay with water, which the workmen call slip.
The vessels, when complete, are dried, with a gradual
heat, in a room, heated to eighty or ninety degrees, and,
after being smoothed from any irregularities of surface,
they are conveyed to the kiln.
Pressing. — The only vessels which can be made in
the wheel, or lathe, are those of a circular form. When
the form is different, the vessel must be made, either by
press-work, or casting. The press-work is executed in
moulds, made of plaster of Paris, one half the figure be-
ing on one side of the mould, and the other half, on the
other side. These fit accurately together. The clay is
first made into two flat pieces, of the thickness of the ar-
ticles ; one of these is pressed into one side of the mould,
and the other into the other side. The superfluous clay
being cut away, the two sides of the mould are brought
together, to unite the two halves of the vessel. The
mould is now separated from the clay, and the article is
finished, as to form. When dry, it is completed by the
addition of handles or other parts, belonging to it. All
vessels, of an oval form, or which have flat sides, may
be made in this way.
Casting. — In the third method, called castings the clay
is used in the state of pulp, sufficiently thin to flow. It
is poured into moulds, made o{ plaster, by which the su-
perfluous water being rapidly absorbed, the clay is depos-
ited, and acquires sufficient solidity to preserve the shape
communicated by the mould. It is then taken out, and
dried, and transferred to the kiln.
Burning. — All vessels, when formed, are in a very
tender and frangible state, before they are submitted to
the action of fire. The burning, or hardening, is per
formed in kilns ; and to preserve the ware from injury,
it is enclosed in cases, or boxes, of burnt clay, called
saggarsy m which it is heated red hot, by the flame cir
23*
270 ARTS OF INDURATION BY HEAT.
culating among the cases. The fire is kept up, from twen
ty-four to forty-eight hours, and the saggars suffered to
cool, before they are removed. The ware is then found
to have acquired great hardness, and is converted into a
dry, sonorous, and extremely bibulous, solid. In this state,
it is called the biscuit. It adheres strongly to the tongue,
and absorbs water in such quantities, that vessels, in this
state, are used as coolers, being kept saturated with wa-
ter, which, as it passes constantly to the outer surface,
generates cold, by its evaporation.
Printing. — When colors, or designs, are to be im-
pressed upon the vessels, it is necessary, in most cases,
that it should be done, before the ware is glazed. In
China, the drawings on the surface of porcelain, and oth-
er wares, are executed by hand, with the pencil ; and the
same method is pursued in Europe, in elaborate pieces of
workmanship. But, in the common figured white-ware,
the designs are first engraved upon copper, and an im-
pression taken on thin paper, in the common mode of
copperplate-printing, except that the color is a metallic
oxide. The paper is then moistened, apphed closely to
the biscuit, and rubbed on ; by w^hich process, the color-
ing matter is absorbed, in consequence of the porosity of
the earthen material. The paper is then w^ashed off,
leaving the printed figure transferred to the sides of the
vessel. Blue and white ware is printed with oxide of
cobalt,* and a black color is imparted, by an admixture
with the oxides of n\anganese and iron.
Glazing. — To prevent the penetration of fluids, it is
necessary, that vessels should be glazed, or covered, with
a vitreous coating. The materials of common glass
would afford the most perfect glazing to crockery-ware,
were it not that the ratio of its expansion and contrac-
tion, is not the same with that of the clay ; so that a
glazing of this sort is liable to cracks and fissures, when
exposed to changes of temperature. A mixture, of equal
parts of oxide of lead and ground flints, is found to be a
* Mr. Parkes informs us, that such improvements are made in the
manufacture of this article, that the Chinese potters are now supplied
from England, with all the cobalt they consume.
CHINA-WARE. EUROPEAN PORCELAIN. 271
durable glaze, for the common cream-colored ware, and
is generally used for that purpose. These materials are
first ground to an extremely fine powder, and mixed with
water, to form a thin liquid. The ware is dipped into
this fluid, and drawn out. The moisture is soon absorb-
ed by the clay, leaving the glazing particles upon the sur-
face. These are afterwards melted, by the heat of the kiln,
and constitute a uniform and durable vitreous coating.
The English and French manufacturers find it neces-
sary to harden their vessels, by heat, or to bring them to
the state of biscuit, before they are glazed ; but the com-
position used by the Chinese resists water, after it has
been once dried in the air, so as to bear dipping in the
glazing Hquid, without injury. This gives them a great
advantage, in the economy of fuel.
China Ware. — The Chinese porcelain excels other
kinds of ware, in the delicacy of its texture, and the par-
tial transparency which it exhibits, when held against the
hght. It h^s been long known and manufactured, by the
Chinese, but has never been successfully imitated, in Eu-
rope, until within the last century. In China, porcelain
is made by the union of two earths, to which they give
the name o^ petuntze, and kaolin^ the former of which is
fusible in the furnace, the latter, not. Both these earths are
varieties of feldspar, the kaolin being feldspar, in a state of
decomposition, and which is rendered infusible, by having
lost the small quantity of potass, w^hich originally entered
into its composition. The petuntze is feldspar, undecom-
posed. These earths are reduced to an impalpable pow-
der, by processes, similar to those already described, and
intimately blended together. When exposed to a strong
heat, the petuntze partially melts, and, enveloping the in-
fusible kaolin, communicates to it a fine serai-transparen-
cy. The glazing is produced by the petuntze alone, ap-
plied in minute powder to the ware, after it is dry.
European Porcelain. — Since the nature of the Chi-
nese earths has been understood, materials, nearly of the
same kind, have been found, in different parts of Europe,
and the manufacture of porcelain has been carried on in
several countries, but particularly at Sevres, in France,
2"?2 AP/a OF INDURATION BY HEAT.
^•ith great success. The European porcelains, in the
elegance and variety of their forms, and the beauty of
the designs which are executed upon them, excel the
manufactures oi the Chinese. But the Oriental porcelain
has not yet been equalled, in hardness, strength, durabili
ty, and the permanency of its glaze. Several of the
processes, which are successfully practised by the Chi
nese, remain still to be learnt by Europeans. The man
ufacturers in Saxony are said to have approached mos^
nearly, in their products, to the character of the Asiatic
porcelain.
The porcelain earths are found in various parts of the
United States, and will, doubtless, hereafter constitute
the material of important manufactures.
The finer and more costly kinds of porcelain derive
their value, not so much from the quality of their mate-
rial, as from the labor bestowed on their external decora-
tion. When the pieces are separately painted by hand,
with devices of different subjects, their value, as speci-
mens of art, depends upon the size of the piece, the num-
ber and brilliancy of the colors employed, and, more
especially, upon the skill and finish exhibited by the ar-
tist, in the design. The manual part of the operation
consists, in mixing the coloring oxide with a fluid medi-
um, commonly an essential oil, and applying it with cam-
els' hair pencils. The colors used are the same, as those
employed in other kinds of enamelling. When one color
requires to be laid over another, this is performed by a
second operation ; and it often happens, that a piece of
porcelain has to go into the enamel-kiln, four or five times,
when a great variety of colors is contained in the painting.
Gilding upon porcelain is performed, by applying the
gold, after its solution in nitro-muriatic acid, ground up
with oil of turpentine, and mixed with a flux. W^hen
exposed to heat, the oxygen, if any is present, escapes,
and a coating of metallic gold remains fixed to the porce-
lain. This has, at first, the appearance of dead gold ;
jut is subsequently burnished, with an instrument of pol-
ished steel, or with an agate, or blood-stone.
The articles, called lustre-ware^ are of two kinds. The
ETRUSCAN VASES. 273
first of these, called gold-lustre, is made of red clay, and
is brushed over with a thin coating of gold, obtained frono
its solution in nitro-muriatic acid, the acid being driven
off by heat. The other kind is called silver-lustre, and
is made of the cream-colored ware, covered, in the same
manner, with a film of platinum.
Etruscan Vases. — This name is given to a kind of
painted antique vases, of great beauty, lightness, and
delicacy, which are dug up in the graves of lower Italy.
Many of them are supposed to be of Grecian, and not of
Etruscan, origin. Some of these vases are entirely black,
and, in this case, there is no separate glazing ; but the m-
terior of the mass has the same appearance with the out-
side. Other vases are furnished with a simple black
coating, but unhke the modern glazing. It appears, from
analysis, that this black color is produced by a carbona-
ceous substance, perhaps bitumen ; but the art of apply-
ing it is unknown to the moderns.
The celeh^ted Portland vase, discovered in the tomb
of xA.lexande^^everus, and for w^hich the Dutchess of
Portland paid a thousand guineas, is said to be made, not
of porcelain, but of glass. The body of the urn consists
of a deep-blue glass, over which is applied a coating of
white semi-transparent glass. The white covering ap-
pears to have been cut away, by the lapidary, in the same
way as the subjects of antique cameos on colored grounds.
Mr. Wedgewood, at a great expense, produced imitations
of this vase, in porcelain.
Among the curiosities of this art, may be mentioned
the magic porcelain of the Chinese. The figures upon
the surface of this ware are executed in such a manner,
that they are said to be invisible, when the vessels are
empty,* but become apparent, when the vessels are filled
with water.
WoivKs ofReferbnce. — Parkks's Chemical Essays, vol ii. ; —
Rees' Cyclopedia, and Edinburgh Encyclopedia, articles Pottery, Por-
celain, &c. ; — Chaptal, Chimie Appliquee aux Arts, torn. iii. ; —
Gray's Operative Chemis-t, 8vo. 1828. — Lardner's Cabinet Cy-
clopedia, 12mo. vol. xxvi.
* See the article Porcelain^ in the Edinburgh Encyclopedia, ascribed
to M. Brogniart.
APPENDIX
I. — Artesian Wells.
Under this name, is designated a cylindrical perfora-
tion, bored vertically down through one or more of the
geological strata of the earth, till it passes into a porous
gravel bed, containing water placed under such incum-
bent pressure, as to make it mount up through the per-
foration, either to the surface, or to a height convenient
for the operation of a pump. In the first case, these
wells are called spouting, or overflowing. This property
is not directly proportional to the depth, as might at first
sight be supposed, but to the subjacent pressure upon the
water. We do not know exactly the period, at which
the borer, or sound, was applied to the investigation of
subterranean fountains, but we beheve the first overflow-
ing wells were made in the ancient French province of Ar-
tois, whence the name of Artesian. These wells, of such
importance to agriculture and manufactures, and which
cost nothing to keep them in condition, have been in use,
undoubtedly, for several centuries, in the northern depart-
ments of France, and in the north of Italy ; but it is not
more than fifty or sixty years, since they became known
in England and Germany. There are now many such
wells in London and its neighborhood, perforated through
the immensely thick bed of the London clay, and even
through some portions of the subjacent chalk. The bor-
ing of such wells has given much insight into the geologi-
cal structure of many districts.
The formation of Artesian wells depends on two things,
essentially distinct from each other ; 1. On an acquain-
tance with the physical constitution, ornature, of the min-
276 APPENDIX.
eral structure of each particular country ; and, 2. On the
skilful direction of the processes, by which we can reach
the water-level, and of those by which we can promote its
ascent in the tube. We shall treat of the best method of
making the well, and then offer some general remarks on
the other subjects.
The operations employed for penetrating the soil are
entirely similar to those daily practised by the miner, in
boring to find metallic veins ; but the well-excavator must
resort to peculiar expedients to prevent the purer water,
which comes from deep strata, mingling with the cruder
waters of the alluvial beds near the surface of the ground,
as also to prevent the small perforation getting eventually
filled with rubbish.
The cause of overflowing wells has been ascribed to
various circumstances. But, as it is now generally ad-
mitted, that the numerous springs. w^hich issue from the
ground proceed from the infiltration of the waters, pro-
gressively condensed in rain, dew, snow, &c., upon the
§urface of our globe, the theory of these interior stream-
lets becomes by no means intricate ; being analogous to
that of syphons and water-jets, as expounded in the trea-
tises of physics. The waters are diffused, after conden-
sation, upon the surface of the soil, and percolate down-
wards through the various pores and fissures of the geo-
logical strata, to be again united subterraneously in veins,
rills, streamlets, or expanded films, of greater or less mag-
nitude or regularity. The beds traversed by numerous
disjunctions will give occasion to numerous interior cur-
rents, in all directions, which cannot be recovered and
brought to the day ; but when the ground is composed
of strata of sand or gravel very permeable to water, sep-
arated by other strata nearly impervious to it, reservoirs
are formed to our hand, from w^hich an abundant supply
of water may be spontaneously raised. In this case, as
soon as the upper stratum is perforated, the waters may
rise, in consequence of the hydrostatic pressure upq^ the
lower strata, and even overflow the surface in a constant
stream, provided the level from which they proceed be
proportionably higher.
ARTESIAN WELLS. 277
The sheets of water occur, principally, at the separa-
tion of two contiguous formations ; and, if the succession
of the geological strata be considered, this distribution of
the water will be seen to be its necessary consequence.
In fact, the lower beds are frequently composed of com-
pact sandstone or hmestone, and the upper beds of clay.
In level countries, the formations being almost always in
horizontal beds, the waters which feed the Artesian wells
must come from districts somewhat remote, where the
strata are more elevated, as towards the secondary and
transition rocks. The copious streams, condensed' upon
the sides of these colder lands, may be therefore regarded
as the proper reservoirs of our wells.
Th^ situation of the intended well being determined
upon, a circular hole is generally dug in the ground, about
six or eight feet deep, and five or six feet wide. In the
centre of this hole, the boring is carried on by two work-
men below, assisted by a laborer above.
The tools used are variously formed, in the shape of
drills, chisels, picks, &:c., screwed upon the end of a
handle which is capable of being lengthened, as the work
proceeds. The whole is suspended from an elastic hori-
zontal pole, which is firmly fixed, at one end, while the
other end can be moved, up and down, by a workman,
producing a vibrating, or picking, motion. At the same
time, other workmen turn or vary the position of the
drill, by means of a cross-bar, so that it acts as in the
common mode of drilling rocks. The dirt and broken
stones are drawn up, by an instrument shaped somewhat
like an auger, which is inserted, from time to time, when
the drill is withdrawn.
It is obvious, that placing and displacing the lengths
of rod, which is done every time that the auger is required
to be introduced or withdrawn, nust, of itself, be ex-
tremely troublesome, independent Df the labor of boring ;
but yet the operation proceeds, when no unpropitious
circymstance attends it, with a facihty almost incredible.
Sometimes, however, rocks intercept the way, which re-
quire great labor to penetrate ; but this is always efiectec
by pecking, w^hich slowly pulverizes the stone. The most
II. 24 XII.
278 APPENDIX.
unpleasant circumstance attendant upon this business is the
occasional breaking of a rod into the hole, which some-
times creates a delay of many days, and an incalculable
labor in drawing up the lower portion.
When the water is obtained, in such* quantities and of
such quality as may be required, the hole is dressed or
finished, by passing down it a diamond chisel, funnel-
mouthed, with a triangular bit in its centre ; this makes
the sides smooth, previous to putting in the pipe. This
chisel is attached to rods, and to the handle, as before
described, and in its descent, the workmen continually
walk round, by which the hole is made smooth and cy-
lindrical. In the progress of the boring, frequent veins
of water are passed through ; but, as these ai'e small
streams, and perhaps impregnated with mineral substances,
the operation is carried on, until an aperture is made into
a main spring, which will flow up to the surface of the
earth. This must, of course, depend upon the level of
its source, which, if in a neighboring hill, will frequently
cause the water to rise up, and produce a continued foun
tain. But, if the altitude of the distant spring happens to
be below the level of the surface of the ground, where the
boring is effected, it sometimes happens, that a well of
considerable capacity is obliged to be dug down to that
level, in order to form a reservoir, into which the water
may flow, and whence it must be raised by a pump ;
while, in the former instance, a perpetual fountain may
be obtained. Hence, it will always be a matter of doubt,
in level countries, whether water can be procured, which
would flow near to, 6r over, the surface ; if this cannot be
effected, the process of boring will be of litde or no ad-
vantage, except as an experiment, to ascertain the fact.
In order to keep the strata pure, and uncontaminated
A^ith mineral springs, the hole is cased, for a considerable
lepth, with a metallic pipe, about a quarter of an incli
mailer than the bore. This is generally made of tin,
viiough sometimes of copper or lead, in convenient
lengths ; and, as each length is let down, it is held by a
shoulder resting in a fork, while another length is sol-
dered to it ; by which means a continuous pipe is carried
MINES. 279
through the bore, as far as may be found necessary, to
exclude land-springs, and to prevent loose earth or sand
from falling in, and chdking the aperture. — Ure^s ^Diction-
ary of Arts, ^&ic.
II. — Mines.
Amidst the variety of bodies, apparently infinite, which
compose the crust of the globe, geologists have demon-
strated the prevalence of a few general systems of rocks,
to which they have given the names of formations, or de-
posits. A large proportion of these mineral systems con-
sists of parallel planes, Vvhose length and breadth greatly
exceed their thickness ; on w^hich account, they are called
stratified rocks ; others occur in very thick blocks, with-
out any parallel stratification, or horizontal seams, of con-
siderable extent.
The stratiform deposits are subdivided into two great
classes ; the primary, and the secondary. The former
seem to have been called into existence, before the crea-
tion of organic matter, because they contain no exuviae of
vegetable or animal beings ; while the latter are more or
less interspersed, and sometimes replete, with organic re-
mains. The primary strata are characterized, moreover,
by the nearly vertical, or highly inclined, position of their
planes ; the secondary lie, for the most part, in a nearly
horizontal position.
Where the primitive mountains graduate down into the
plains, rocks of an intermediate character appear, which,
though possessing a nearly vertical position, contain a few
vestiges of animal beings, especially shells. These have
been called transition, to indicate their being the passing
links between the first and second systems of ancient de-
posits. They are distinguished by the fractured and ce-
mented texture of their planes, for which reason they are
sometimes called, conglomerate.
Between these, and the truly secondary rocks, another
very valuable series is interposed, in certain districts of
the globe ; namely, the coal-measures, the paramount for-
mation of Great Britain. The coal strata are disposed
in a basin form, and alternate with parallel beds of sand-
280 APPENDIX.
Stone, slate-clay, iron-stone, and occasionally limestone.
Some geologists have called the coal-measures the medi-
al formation. •
In every mineral plane, the inchnation and direction are
to he noted ; the former, being the angle ^vhich it forms
with the horizon, the latter, the point of the azimuth, or
horizon, towards which it dips, as west, northeast, south,
&c. The direction of the bed is that of a horizontal line
drawn in its plane ; and which is also denoted by the point
of the compass. Since the lines of direction and inclina-
tion are at right angles to each other, the first may always
be inferred from the second ; for when a stratum is said
to dip to the east or west, this implies, that its direction
is north and south.
The smaller sinuosities of the bed are not taken into
account, just as the windings of a river are neglected, in
stating the line of its course.
Masses are mineral deposits, not extensively spread m
parallel planes, but irregular heaps, rounded or oval, en-
veloped, in whole or in a great measure, by rocks of a
different kind. Lenticular masses being frequently placed
between two horizontal, or inclined, strata, have been
sometimes supposed to be stratiform themselves, and
have been accordingly denominated by the Germans,
liegende stocke^ ^^**^^ heaps, or blocks.
The orbicular masses often occur in the interior of un-
stratified mountains, or in the bosom of one bed.
.A'es^s, concretions, nodules, are small masses found* in
the middle of strata ; the first being commonly in a fria-
ble state ; the second often kidney-shaped, or tuberous ;
the third nearly round, and encrusted, like the kernel of
an almond.
Lodes, or large veins, are flattened masses, with their
opposite surfaces not parallel, which consequently termi-
nate like a wedge, at a greater or less distance, and do
not run parallel with the 'rocky strata in which they lie,
but cross them, in a direction not far from the perpendic-
ular ; often traversing several different mineral planes.
The lodes are sometimes deranged in their course, so as
to pursue, for a little way, the spEce between two con-
MINES. 281
t^guous strata ; at other times they divide, into several
branches. The matter which fills the lodes is, for the
most part, entirely different from the rocks they pass
through ; or, at least, it possesses peculiar features.
This mode of existence, exhibited by several mineral
substances, but which has been long known with regard to
metallic ores, suggests the idea of clefts, or rents, having
been made in the stratum, posterior to its consolidation
and of the vacuities having been filled with foreign matter,
either immediately, or after a certain interval. There
can be no doubt, as to the justness of the first part of the
proposition, for there may be observed, round many lodes,
undeniable proofs of the movement or dislocation of the
rock ; for example, upon each side of the rent, the same
strata are no longer situated in the same plane as before,
but make greater or smaller angles with it ; or the stratum
upon one side of the lode is raised considerably above, or
depressed considerably below, its counterpart, upon the
other side. Whh regard to the manner in which the rent
has been filled, different opinions may be entertained. In
the lodes which are widest, near the surface of the ground,
and graduate into a thin wedge, below, the foreign matter
would seem to have been introduced, as into a funnel, at
the top, and to have carried along with it, in its fluid state,
portions of rounded gravel and organic remains. In oth-
er cases, other conceptions seem to be more probable ;
since many lodes are largest, at their under part, and be-
come progressively narrower, as they approach the sur-
face ; from which circumstance it has been inferred, that
the rent has been caused by an expansive force, acting
from within the earth, and that the foreign matter, having
been injected in a fluid state, has afterwards slowly crys-
tallized. This hypothesis accounts, much better than the
other, for most of the phenomena observable in mineral
veins, for the alterations of the rock at their sides, for the
crystaUization of the different substances interspersed in
them, for the cavities bestudded with little crystals, and
for many minute peculiarities. Thus, the large crystals
of certain substances, which line the walls of hollow veins,
have sometimes their under surfaces besprinkled with
24*
282 APPENDIX.
small crystals of sulphurets, arseniurets, &c., while their
upper surfaces are quite smooth ; suggesting the idea ol a
slow sublimation of these volatile matters from below, by
the residual heat, and their condensation upon the under
faces of the crystalline bodies, already cooled. This phe-
nomenon affords a strong indication of the igneous origin
of metalliferous veins.
In the lodes, the principal matters which fill them are
to be distinguished from the accessory substances ; the
latter being distributed, irregularly, amidst the mass of
the first, in crystals, nodules, veins, seams, &c. The
non-metalliferous exterior portion, which is often the
largest, is called gangue, from the German gang^ vein.
The position of a vein is denoted, like that of the strata,
by the angle of inclination, and the point of the horizon
towards which they dip, whence the direction is deduced.
Veins are merely small lodes, which sometimes tra-
verse the great ones, ramifying, in various directions, and
in different degrees of tenuity.
A metalliferous substance is said to be disseminated ,
when it is dispersed in crystals, spangles, scales, globules,
&c., through a large mineral mass.
Certain ores, which contain the metals most indispensa-
ble to human necessities, have been treasured up by the
Creator in very bountiful deposits ; constituting either
great masses in rocks of different kinds, or distributed in
lodes, veins, nests, concretions, or beds, with stony and
earthy admixtures ; the w^hole of which become the ob-
jects of mineral exploration. These precious stones occur
in different stages of the geological formations, but their
main portion, after having existed, abundantly, in the sev-
eral orders of the primary strata, suddenly cease to be
found, towards the middle of the secondary. Iron ores
are the only ones which continue among the more mod-
ern deposits, even so high as the beds immediately beneath
the chalk, when they also disappear, or exist merely as
coloring miitters of the tertiary earthy beds.
The strata of gneiss and mica-slate constitute, in Eu-
rope, the grand metallic domain. There is hardly any
kind of ore, which does not occur there in sufficient abun-
MINES. 283
dance, to become the object of mining operations, and
many are found nowhere else. The transition rocks,
and the lower part of the secondary ones, are not so rich,
neither do they contain the same variety of oyes. But
this order of things, which is presented by Great Britain,
Germany, France, Sweden, and Norway, is far from
forming a general law ; since in Equinoctial America, the
gneiss is but little metalliferous ; while the superior b.Tata,
such as the clay-schists, the sienitic porphyries,' the lime-
stones, which complete the transition series, as also sev-
eral secondary deposits, include the greater portion of.
the immense mineral wealth of that region of the globe.
All the substances, of which the ordinary metals form
the basis, are not equally abundant in Nature ; a great
proportion of the numerous mineral s])ecies, which figure
in our classifications, are mere varieties, scattered up and
down in the cavities of the great masses, or lodes. The
workable ores are few in number, being mostly sulphurets,
some oxides, and carbonates. These occasionally form,
of themselves, very large masses ; but, more frequently,
they are blended with lumps of quartz, feldspar, and car-
bonate of lime, which form the main body of the deposit ;
as happens, always, in proper lodes. The ores, in that
case, are arranged in small layers, parallel to the strata oi
the formation, or in small veins, which traverse the rock
in all directions, or in nests, or concretions, stationed ir-
regularly, or finally disseminated, in hardly visible parti-
cles. These deposits sometimes contain, apparently,
only one species of ore, sometimes several, which must
be mined together, as they seem to be of contemporane-
ous formation ; whilst, in other cases, they are separable,
havmg been probably formed at different epochs.
Lodes, or mineral veins, are usually distinguished, by
English miners, into at least four species. 1. The rake-
vein ; 2. The pipe-vein ; 3. The flat, or dilated, vein ;
and 4. The interlaced mass, (stock-tDerke^) indicating the
union of a multitude of small veins, mixed, in every possi-
ble direction, with each other and with the rock.
1. The rake vein is a perpendicular mineral fissure ;
and is the form best known among practical miners. It
284 APPENDIX.
commonly runs in a straight line, beginning at the super-
ficies of the strata, and cutting them downwards, generally
further than can be reached. This vein sometimes stands
quite perpendicular ; but it more usually inclines, or hangs
over, at a greater or smaller angle, or slope, which is
called, by the miners, the hade, or hading, of the vein.
The line of direction in which the fissure runs is called,
the bearing of the vein.
2. Tlie pipe vein resembles, in many respects, a huge,
irregular cavern, pushing forward into the body of the
earth, in a sloping direction, under various inclinations,
from an angle of a (ew degrees to the horizon, to a dip of
forty-five degrees, or more. The pipe does not, in general,
cut the strata across, like the rake-vein, but insinuates
itself between them ; so that, if the plane of the strata be
nearly horizontal, the bearing of the pipe-vein will be con-
formable ; but if the strata stand up at a high angle, the
pipe shoots down, nearly headlong, like a shaft. Some
pipes are very wide and high, others are very low and
narrow, sometimes not larger than a common mine, or
drift.
3. The^a^, or dilated, vein is a space or opening, be-
tween two strata or beds of stone, the one of which lies
above, and the other below, this vein, like a stratum of
coal between its roof and pavement ; so that the vein and
the strata are placed in the same plane of inclination.
These veins are subject, like coal, to be interrupted,
broken, and thrown up or down, by slips, dykes, or other
interruptions of the regular strata. In the case of a me-
tallic vein, a slip often increases the chance of finding
more treasure. Such veins do pot preserve the parallel-
ism of their beds, characteristic «^f coal-seams ; but vary,
excessively, in thickness, within a moderate space. Flat
veins occur, frequently, in limestone, either in a horizontal
or declining direction. The flat, or strata, veins open and
close, as the rake-veins also do.
To these may be added, the accumulated vein, or ij-
regularmass, {hutzenwerke,) a great deposit, placed, with-
out any order, in the bosom of the rocks, apparently
filling up cavernous spaces.
MINES. 28b
The interlaced masses are more frequent in primitive
formations, than in the others, and tin is the ore which
most commonly affects this locality.
These gangues, such as quartz, calcareous spar, fluor
spar, heavy spar, &c., and a great number of other sub-
stances, although of little or no value in themselves, be-
come of great consequence to the miner, either by point-
ing out, by their presence, that of certain useful *hiinerals,
or by characterising, in their several associations, difier-
ent deposits of ores, of which it may be possible to follow
the traces, and to discriminate the relations, often of a
comphcated kind, provided we observe assiduously the
accompanying gangues.
Mineral veins are subject to derangements, in their
course, which are called shifts, or faults. Thus, when a
transverse vein throws out, or intercepfs a longitudinal one,
we must commonly look for the rejected vein on the side of
the obtuse angle, which the direction of the latter makes
with that of the former. When a bed of ore is deranged
by a fault, we must observe, whether the shp of the strata
be upwards or downwards ; for, in either circumstance, it
is only by pursuing the direction of the fault, that we can
recover the ore ; in the former case, by mounting, in the
latter, by descending, beyond the dislocation.
When two veins intersect each other, the direction of
the offcast is a subject of interest, both to the miner and
the geologist. In Saxony, it is considered as a general
fact, that the portion thrown out is always upon the side
of the obtuse angle, a circumstance which holds also in
Cornwall ; and the more obtuse the angle, the out-throw
is the more considerable. A vein may be thrown out, on
meeting another vein, in a line which approaches either
towards its inclination, or its direction. The Cornish
miners use two different terms, to denote these two modes
of rejection ; for the first case, they say the vein is
heaved ; for the second, it is started.
GENERAL OBSERVATIONS ON THE LOCALITIES OF ORES
AND ON THE INDICATIONS OF METALLIC MINES,
1. Tin exists, principally, in primitive rocks, appearing
286 APPENDIX.
either in interlaced masses, in beds, or as a constituent
part of the rock itself, and, more rarely, in distinct veins.
Tin ore is found indeed, sometimes, in alluvial land, filling
up low situations between lofty mountains.
2. Gold occurs either in beds, or in veins, frequently
in primitive rocks ; though, in other formations, and par-
ticularly in alluvial earth, it is also found. When this
metal exfsts in the bosom of primitive rocks, it is partic-
ularly in schists ; it is not found in serpentine, but it is
met with in gray-wacke, in Transylvania. The gold of
alluvial districts, called gold of washing, or transport, oc-
curs, as well as alluvial tin, among the debris of the more
ancient rocks.
' 3. Silver is found, particularly in veins and beds, in
primitive and transition formations ; though some veins of
this metal occur in 'secondary strata. The rocks, richest
in it, are, gneiss, mica-slate, clay-slate, gray-wacke, and
old alpine limestone. Localities of silver ore itself are not
numerous, at least in Europe, among secondary forma-
tions ; but it occurs in combination with the ores of cop'
per, or of lead.
4. Copper exists in the three mineral epochas : 1. in
primitive rocks, principally in the state of pyritous copper,
in beds, in masses, or in veins ; 2. in transition districts,
sometimes in masses, sometimes in veins of copper py-
rites ; 3. in secondary strata, especially in beds of cupre-
ous schist.
5. Lead occurs, also, in each of the three mineral epo-
chas ; abounding, particularly, in primitive and transition
grounds, where it usually constitutes veins, and occasion-
ally beds, of sulphuretted lead, (galena.) The same ore
is found in strata, or in veins, among secondary rocks, as-
sociated, now and then, with ochreous iron-oxide and cal-
amine, (carbonate of zinc,) and it is sometimes dissemi-
nated, in grains, through more recent strata.
6. Iron is met with, in four different mineral eras, but
in different ores. Among primitive rocks, magnetic iron
ore and specular iron ore occur chiefly in beds, some-
times of enormous size ; the ores of red, or brown, oxide
of iron (haematite) are found generally in veins, or, occa-
MINES. 287
sionally, in masses with sparry iron, both in primitive and
transition rocks ; as also, sometimes, in secondary strata ;
but, more frequently, in the coal-measure strata, as beds
of clay-ironstone, of globular iron-oxide, and carbonate
of iron. In alluvial districts, we find ores of clay-iron-
stone, granular iron-ore, bog-ore, swamp-ore, and mead-
ow-ore. The iron ores, which belong to the primitive
period, have almost always the metallic aspect, wiih a
richness amounting even to eighty per cent, of iron, while
the ores in the posterior formations become, in general,
more and mo're earthy, down to those in alluvial soils,
some of which present the appearance of a common stone,
and afford not more than twenty per cent, of metal, though
its quahty is often excellent.
7. Mercury occurs principally among secondary stra-
ta, in disseminated masses, along with combustible sub-
stances ; though the metal is met with, occasionally, in
primitive countries.
8.* Cobalt belongs to the three mineral epochas ; i.6
most abundant deposits are veins in primitive rocks.
Small veins, containing this metal, are found, however, in
secondary strata.
9. Antimony occurs in veins, or beds, among primitive
and transition rocks.
10, 11. Bismuth and nickel do not appear to consti-
tute the predominating substance of any mineral deposits ;
but they often accompany cobalt.
12. Zinc occurs in the three several formations ; name-
ly, as sulphuret or blende, particularly in primitive and tran-
sition rocks ; as calamine, in secondary strata, usually along
with oxide of iron, and sometimes with sulphuret of lead.
An acquaintance with the general results, collected and
classified by geology, must be our first guide in the inves-
tigation of mines. This enables the observer to judge,
whether any particular district should, from the nature
and arrangement of its rocks, be susceptible of including
within its bosom, beds of workable ores. It indicates,
also, to a certain degree, what substances may probably
be met with in a given series of rocks, and what locality
these substances will preferably affect For want of a
288 APPENDIX.
knowledge of these facts, many persons have gone blindly
into researches, equally absurd and ruinous.
Formerly, indications of mines were taken from very
unimportant circumstances ; from thermal waters, the heat
of which was gratuitously referred to the decomposition
of pyrites ; from mineral waters, whose course is, howev-
er, often from a far distant source ; from vapours incum-
bent over particular mountain groups ; from the snows
melting faster in one mineral district than another ; from
the difterent species of forest trees, and from the greater
or less vigor of vegetation, &c. In general, all such in-
dications are equally fallacious with the divining rod, and
the compass made of a lump of pyrites, suspended by a
thread.
Geognostic observation has substituted more rational
characters of metallic deposits, some of which may be
called negative^ and others positive.
The negative indications are derived from that peculiar
geological constitution, which, from experience, or getieral
principles, excludes certain metallic matters ; for example,
granite, and, in general, every primitive formation, forbids
the hope of finding within them combustible fossils, (pit-
coal,) unless it be beds of anthracite ; there also it would be
vain to seek for sal gem. It is very seldom that granite
rocks include silver ; or limestones, ores of tin. Volcanic
territories never afford any metallic ores worth the work-
ing ; nor do extensive veins usually run into secondary ana
alluvial formations. The richer ores of iron do not occur
in secondary strata ; and the ores of this metal, peculiar
to these localities, do not exist among primary rocks.
Among positive indications, some are proximate, and
others remote. Tne proximate are, an efflorescence, so
to speak, of the subjacent metallic masses ; magnetic at-
traction, for iron ores ; bituminous stone, or inflammable
gas, for pit-coal ; the frequent occurrence of fragments
of particular ores, &c. The remote indications consist
in the geological epocha and nature of the rocks. From
the examples previously adduced, marks of this kind ac-
quire new importance, when, in a district susceptible of
including deposits of workable ores, the gangues, or vein-
• MINES. 289
stones, are met with, which usually accompany any partic
ular metal. The general aspect of mountains, whose
flanks present gentle and continuous slopes, the frequency
of sterile veins, the presence of metalliferous sands, the
neighborhood of some known locality of an ore, for in-
stance, that of iron-stone, in reference to coal ; lastly,
the existence of salt springs and mineral waters may fur-
nish some indications.
In speaking of remote indications, we may remark, that,
in several places, and particularly near Clausthal, in the
Hartz, a certain ore of red oxide of iron occurs above the
most abundant deposits of the ores of lead and silver ;
whence it has been named by the Germans, the iron-hat.
It appears that the iron ore, rich in silver, which is worked
in America, under the name of pacos, has some analogy
with this substance ; but 'iron ore is, in general, so plen-
tifully diffused on the surface of the soil, that its presence
can be regarded as only a remote indication, relative to
other mineral substances, except in the case of clay-iron-
stone with coal.
Of the instruments and processes of subterranean op-
erations.— It is by the aid of geometry, in the first place,
that the miner studies the situation of the mineral depos-
its, on the surface, and in the interior, of the ground ; de-
termines the several relations of the veins and the rocks ;
and becomes capable of directing the perforations towards
a suitable end.
The instruments are, 1. The magnetic compass, which
is employed to measure the direction of a metallic ore,
wherever the neighborhood of iron does not interfere with
:ts functions. 2. The graduated semicircle, which serves
to measure the inchnation, which is also called the cli-
nometer. 3. The chain, or cord, for measuring the dis-
tance of one point from another. 4. When the neighbor-
hood of iron renders the use of the magnet uncertain, a
plate, or plane table, is employed.
The. dials of the compasses, generally used in the most
celebrated mines, are graduated into hours ; most com-
monly into twice twelve hours. Thus the whole limb is
divided into twenty-four spaces, each of which contains
II. 25 XII
290 APPENDIX.
fifteen degrees, equal to one hour. Each hour is subdi-
vided into eight parts.
Means of penetrating into the interior of the earth. — >
In order to penetrate into the interior of the earth, and to
extract from it the objects of his toils, the miner has at
his disposal several means, which may be divided into three
classes ; 1. manual tools, 2. gunpowder , and 3. fire.
The tools used by the miners of Cornwall and Devonshire
are the following :
The pick. It is a light tool, and somewhat varied in
shape, according to circumstances One side, used as a
hammer, is called the poll, and is employed to drive in the
gads, or to loosen and detach prominences. The point
is of steel, carefully tempered, and drawn under the ham-
mer to the proper form. The French call it pointerolle.
The gad. It is a wedge of steel, driven into crev-
ices of rocks, or into small openings made with the point
of the pick.
The minerh shovel. It has a pointed form, to ena-
ble it to penetrate among the coarse and hard fragments
of the mine rubbish. Its handle being somewhat bent, a
man's power may be conveniently applied, without bend-
ing his body. The blasting, or shooting, tools are, a
sledge or mallet, borer, claying-bar, needle or nail, scra-
per, tamping-bar. Besides these tools, the miner requires
a powder-horn, rushes to be filled with gunpowder, tin car-
tridges, for occasional use in wet ground, and paper rubbed
over with gunpowder, or grease, for the smifts, or fuses.
The borer is an iron bar, tipped with steel, formed
like a thick chisel, and is used by one man holding it
straight in the hole, with constant rotation on its axis, while
another strikes the head of it, with the iron sledge, or
mallet. The hole is cleared out, from time to time, by
the scraper, which is a flat iron rod, turned up at one end.
If the ground be very wet, and the hole gets full of mud,
it is cleaned out by a stick, bent at the end into a fibrous
brush, called a swab-stick.
The hole must be rendered as dry as possible, which is
effected very simply, by filling it partly with tenacious
flay, and then driving into it a tapering iron rod, which
MINES. 291
nearly fills its calibre, called the claying-har. This be-
ing forced in with great violence condenses the clay into
all the crevices of the rock, and secures the dryness of
the hole. Should this plan fail, recourse is had to tin
cartridges, furnished with a stem, or tube, through which
the powder may be inflamed. When the holt is dry, and
the charge of powder introduced, the nail^ a small taper
rod of copper, is inserted, so as to reach the bottom of the
hole, which is now ready for tamping. By this difficult
and dangerous process, the gunpowder is confined, and
the disruptive effect produced. Different substances are
employed for tamping ^ or cramming the hole, the most
usual one being any soft species of rock, free from sili-
cious, or flinty, particles. Small quantities of it only are
introduced at a time, and rammed very hard, by the tamp-
ing-bar^ which is held steadily by one man, and struck
with a sledge by another. The hole being thus filled, the
nail is withdrawn, by putting a bar through its eye, and
striking it upwards. Thus, a small perforation, or vent,
is left for the rush which communicates the fire.
Besides the improved tamping-bar, faced with hard cop-
per, other contrivances have been resorted to, for dimin-
ishing the risk of those dreadful accidents that frequently
occur in this operation. Dry sand is sometimes used as
a tamping material ; but there are many rocks, for the
blasting of which it is ineffective. Tough clay will answer
better, in several situations. For conveying the fire, the
large and long green rushes, which grow in marshy ground,
are selected. A slit is made in one side of the rush,
along which the sharp end of a bit of stick is drawn, so as
to extract the pith, when the skin of the rush closes again,
by its own elasticity. This tube is filled up with gunpow-
der, dropped into the vent-hole, and made steady with a
bit of clay. A paper smift., adjusted to burn a proper
time, is then fixed to the top of the rush tube, and kindled,
when the men of the mine retire to a safe distance.
Gunpowder is the most valuable agent of excavation ,
possessing a power which has no limit, and which can act
every where, even under water. Its introduction, in 1615,
caused a great revolution in the mining art.
292 APPENDIX.
It is employed in mines, in different manners, and in
different quantities, according to circumstances. In all
cases, however, the process resolves itself into boring a
hole, and enclosing a cartridge in it, which is afterwards
made to explode. The hole is always cylindrical, and is
usually madf by means of the borer, a stem of iron ter-
minated by a blunt-edged chisel. It sometimes ends in a
cross, formed by two chisels set transversely. The work-
man holds the stem in his left hand, and strikes it w^ith an
iron mallet, held in his right. He is careful to turn the
punch a very little round, at every stroke. Several punches
are employed, in succession, to bore one hole ; the first
shorter, the latter ones longer, and somewhat thinner.
The rubbish is whhdrawn, as it accumulates at the bottom
of the hole, by means of a picker, which is a small spoon,
or disc of iron, fixed at the end of a slender iron rod.
When holes of a large size are to be made, several men
must be employed ; one, to hold the punch, and one or
more, to wield the iron mallet. The perforations are sel-
dom less than an inch in diameter, and eighteen inches
deep ; but they are sometimes tw^o inches wide, with a
depth of fifty inches.
The gunpowder, when used, is most commonly put up
in paper cartridges. Into the side of the cartridge, a small
cylindrical spindle, or piercer^ is pushed. In this state,
the cartridge is forced down to the bottom of the hole,
which is then stuffed, by- means of the tamping-bar, with
bits of dry clay, or friable stones coarsely pounded. The
peircer is now withdrawn, which leaves in its place a
channel, through which fire may be conveyed to the charge.
This is executed, either by pouring gunpowder into that
passage, or by inserting into it, reeds, straw-stems, quills,
or tubes of paper, filled with gunpowder. This is explod-
ed by a long match, which the workmen kindle, and then
retire to a place of safety.
As the piercer must not only be slender, but stiff, so
as to be easily withdrawn when the hole is tamped, iron
spindles are usually employed, though they occasionally
give rise to sparks, and, consequently, to dangerous acci-
dents, by their friction against the sides of the hole. Brass
MINES 5?^3
piercers have been sometimes tried, but they twist and
break too readily
Each hole bored in a mine should be so placed, in ref-
erence to the schistose-structure of the rock, and to its
natural fissures, as to attack and blowup the least resisting
masses. Sometimes, the rock is prepared, beforehand, for
splitting in a certain direction, by means of a narrow chan
nel, excavated wath the small hammer.
The quantity of gunpowder should be proportional to
the depth of the hole, and the resistance of the rock ; and
merely sufficient to spht it. Any thing additional w^ould
serve no other purpose than to throw the fragments about
the mine, without increasing the useful effect. Into the
holes of about an inch and a quarter diameter, and eigh-
teen inches deep, only two ounces of gunpowder are put.
It appears, that the effect of the gunpowder may be
augmented, by leaving an empty space above, in the mid-
dle of, or beneath, the cartridge. In the mines of Sile-
sia, the consumption of gunpowder has been eventually
reduced, without diminishing the product of the blasts,
by mixing saw^dust with it, in certain proportions. The
hole has also been filled up with sand, in some cases, ac-
cording to Mr. Jessop's plan, instead of being packed
with stones, which has removed the danger of the tamp-
ing operation. The experiments, made in this way, have
given results very advantageous, in quarry blasts, with great
charges of gunpowder ; but less favorable, in the small
charges employed in mines.
Water does not oppose an insurmountable obstacle to
the employment of gunpowder ; but when the hole cannot
be made dry, a cartridge bag, impermeable to water, must
be used, provided with a tube, also impermeable, in which
:he piercer is placed.
After the explosion of each mining charge, wedges and
levers are employed, to drag away, and break down, what
has been shattered.
Wherever the rock is tolerably hard, the use of gun
powder is more economical, and more rapid, than any tool'
work, and is, therefore, always preferred. A gallery, for
example, a yard and a half high, and a yard wide, the
25*
294 APPENDIX.
piercing of which, by the hammer, formerly cost from five
to ten pounds sterling the running yard, in Germany, is
executed, at the present day, by gunpowder, at from two
to three pounds. When, however, a precious mass of
ore is to be detached ; when the rock is cavernous, which
nearly nullifies the action of gunpowder ; or when there is
reason to apprehend that the shock, caused by the explo-
sion, may produce an injurious fall of rubbish, hand-tools
alone must be employed.
In certain rocks and ores, of extreme hardness, the use,
both of tools and gunpowder, becomes very tedious and
costly. Examples to this effect are seen in the mass of
quartz, mingled with copper pyrites, worked at Rammels-
burg, in the Hartz ; in the masses of stanniferous granite
of Geyer and Altenberg, in the Erzgebirge of Saxony, &c.
In these circumstances, fortunately very rare, the action
of fire is used with advantage, to diminish the cohesion of
the rocks and the ores. The employment of this agent
is not necessarily restricted to these difficult cases. It
was formerly applied, very often, to the working of hard
substances ; but the introduction of gunpowder into the
mining art, and the increase in the price of wood, occa-
sion fire to be little used as an ordinary means of excava-
tion, except in places, where the scantiness of the popula-
tion has left a great extent of forest-timber, as happens at
Kongsberg in Norway, at Dannemora in Sweden, at Fel-
sobanya in Transylvania, &c.
The action of fire may be applied to the piercing of a
gallery, or to the advancement of a horizontal cut, or to
the crumbling down of a mass of ore, by the successive
upraising of the roof of a gallery already pierced. In any
of these cases, the process consists in forming bonfires,
the flame of which is made to play upon the parts to be
attacked. All the workmen must be removed from the
mine, during, and even for some time after, the combus-
tion. When the excavations have become sufficiently
cool to allow them to enter, they break down with levers
and wedges, or even by means of gunpowder, the masses
which have been rent and altered by the fire.
To complete our account of the manner in which man
MINES. 295
may penetrate into the interior of the earth, we must point
out the form of the excavations that he should make in it.
In mines, three principal species of excavations may
be distinguished, viz.; shafts, galleries ^ and the cavities
of greater or less magnitude, which remain in the room
of the old workings.
A shaft, or pit, is a prismatic, or cylindrical, hollow
space, the axis of which is either vertical, or much inclin-
ed to the horizon. The dimension of the pit, which is
never less than thirty-two inches in its narrowest diameter,
amounts, sometimes, to several yards. Its depth may ex-
tei]yd to one thousand feet, and more. Whenever a shaft
is opened, means must be provided to extract the rubbish,
which continually tends to accumulate at its bottom, as
well as the waters, which may percolate down into it ; as
also to facilitate the descent and ascent of the workmen
For some time a wheel and axle, erected over the mouth
of the opening, which serve to elevate one or two buckets,
of proper dimensions, may be sufficient for most of these
purposes. But such a machine becomes, ere long, inad-
equate. Horse-whims, or powerful steam-engines, must
then be had recourse to ; and effectual methods of support
must be employed, to prevent the sides of the shaft from
crumbling, and falling down.
A gallery is a prismatic space, the straight or winding
axis of which does not usually deviate much from the hor-
izontal line. Two principal species are distinguished ;
the galleries of elongation, which follow the direction of
a bed, or a vein ; and the transverse galleries, which in-
tersect this direction under an angle, not much different
from ninety degrees. The most ordinary dimensions of
galleries are a yard wide, and two yards high ; but many,
still larger, may be seen, transversing thick deposites of
ore. There are few, whose width is less than twenty-four
inches, and height less than forty; such small drifts serve
merely as temporary expedients in workings. Some gal-
leries are several leagues in length. We shall cescribe,
in the sequel, the means which are, for the most part,
necessary to support the roof and the walls. The rubbish
is removed by wagons, or wheel-barrows, of various kinds;
296 APPENDIX.
It is impossible to advance the boring of a shaft, or gal
lery, beyond a certain rate ; because only a limited set of
workmen can be made to bear upon it.
There are some galleries which have taken more than
thirty years to perforate. The only expedient for accel-
erating the advance of a gallery, is, to commence, at sev-
eral points of the line to be pursued, portions of galleries,
which may be joined together on their completion.
Whether tools, or gunpowder, be used, in making the
excavations, they should be so applied, as to render the
labor as easy and quick as possible, by disengaging the
mass out of the rock, at two or three of its faces. The
effect of gunpowder, wedges, or picks, is then much more
powerful. The greater the excavation, the more impor-
tant is it to observe this rule. With this intent, the work-
ing is disposed in the form of steps, (gradins,) placed
like those of a stair ; each step being removed, in succes-
sive portions, the whole of which, except the last, are
disengaged on three sides, at the instant of their being at-
tacked.
The substances to be mined occur in the bosom of
the earth, under the form of alluvial deposits, beds, pipe-
veins or masses, threads or small veins, and rake-veins.
When the existence of a deposit of ore is merely sus-
pected, without positive proofs, recourse must be had to
labors of research, in order to ascertain the richness, na-
ture, and disposition, of a supposed mine. These are
divided into three kinds ; open workings, subterranean
workings, and boring operations.
1 . The working by an open trench has for its object
to discover the outcropping, or basset edges of strata, or
veins. It consists in opening a fosse of greater or less
width, which, after removing the vegetable mould, the
alluvial deposits, and the matters disintegrated by the at
mosphere, discloses the native rocks, and enables us to
distinguish the beds, which are interposed, as well as the
veins which traverse them ; the trench ought always to be
opened in a direction perpendicular to the line of the sup
posed deposit. This mode of investigation costs little
DEPTH OP MINES. 297
Dut it seldom gives much insight. It is chiefly employed
for verifying the existence of a supposed bed, or vein.
The subterranean workings afibrd much more satisfac-
tory knowledge. They are executed by different kinds
of perforations ; viz. by longitudinal galleries^ hollowed
out of the mass of the beds or veins themselves, in fol-
lowing their course ; by transverse galleries, pushed at
right angles to the direction of the veins ; by inclined
shafts, which pursue the slope of the deposits, and are
excavated in their mass ; or, lastly, hy perpendicular pits.
If a vein or bed unveils itself on .the flank of a moun-
tain, it may be explored, according to the greater or less
slope of its inclination, either by a longitudinal gallery,
opened in its mass from the outcropping surface, or by
a transverse gallery, falling upon it in a certain point,
from which either an oblong gallery, or a sloping shaft,
may be opened.
If our object be to reconnoitre a highly inclined stra-
tum, or a vein in a level country, we shall obtain it, with
sufficient precision, by means of shafts, eight or ten yards
deep, dug at thirty yards distance from one another, ex-
cavated in the mass of ore, in the direction of its depo-
sit. If the bed is not very much inclined, only forty-five
degrees, for example, vertical shafts must be opened in
the direction of its roof, or of tffe superjacent rocky stra
tum, and galleries must be driven from the points in
which they meet the ore, in the line of its direction.
When the rocks, w^hich cover valuable minerals, are not
of very great hardness, as happens generally with the coal
formation, with pyritous and aluminous slates, sal gem,
and some other minerals of the secondary strata, the bor-
er is employed with advantage, to ascertain their nature.
This mode of investigation is economical, and gives, in
such cases, a tolerably exact insight into the riches of the
interior. The method of using the borer has been de-
scribed under Artesian Wells. — Ure''s ' Diet. ofJlrts,'^ Sf^c.
III. — Depth of Mines.
At the third meeting of the British Association, Mr.
Taylor exhibited a section, showing the depths of shafts
298 APPENDIX.
of the deepest mines in the world, and their position in
relation to the level of the sea.
The absolute depths of the principal ones were :
Feet.
1. The shaft, called Roehrobichel, at the Kitspiihl mine,
in the Tyrol, 2764
2. At the Sampson mine, at Andreasberg, in the Hartz, .... 2230
3. At the Valenciana mine, at Guanaxuato, Mexico, 1770
4. Pearce's shaft, at the Consolidated mines, Cornwall, .... 1464
5. At Wheal Abraham mine, Cornwall, 1452
6. At Dolcoath mine, Cornwall, 1410
7. At Ecton mine, Staffordshire, 1380
8. Woolf's shaft, at the Consolidated mines, 1350
These mines are, however, very differently situated,
with regard to their distance from the centre of the earth ;
as the last on the list, Woolf's shaft, at the Consolidated
mines, has twelve hundred and thirty feet of its depth be-
low the surface of the sea ; while the bottom of the shaft
of Valenciana, in Mexico, is near six thousand feet in
absolute height above the tops of the shafts in Cornwall.
The bottom of the shaft, at the Sampson mine, in the
Hartz, is but a few fathoms under the level of the ocean ;
and this, and the deep mine of Kitspiihl, form, therefore,
intermediate links between those of jSlexico and Cornwall.
Mr. Taylor stated, that, taking the diameter of the
earth at eight thousand miles, and the greatest depth un-
der the surface of the se^ being twelve hundred and thir-
ty feet, or about one fourth of a mile, it follows, that we
have only penetrated to the extent of ^^^-^tj P^^^t of the
earth's diameter.
IV. — Canals in the United States.
The Americans have not rested satisfied with the nat-
ural inland navigation afforded by their rivers and lakes,
nor made the bounty of Nature a plea for idleness, or want
of energy ; but, on the contrary, they have been zealously
engaged in the work of internal improvement ; and their
country now numbers, among its many wonderful artifi-
cial lines of communication, a mountain rail-way, which,
in boldness of design, and difficulty of execution, I can
compare to no modern works I have ever seen, except-
ng, perhaps, the passes of the Simplon, and MontCenis,
CANALS IN THE UNITED STATES. 299
in Sardinia ; but even these remarkable passes, viewed
as engineering works, did not strike me as being more
wonderful than the Alleghany rail-way, in the United
States.
The objects, to which that enterprising people have
chiefly directed their exertions for the advancement of their
country in the scale of civilization, are, the removal of ob-
s-rructions in navigable rivers ; the junction of different
tracts of natural navigation ; the connection of large towns ;
and the formation of lines of communication from the At-
lantic ocean to the great lakes, and the valleys of the
Mississippi, Missouri, and Ohio. The number and ex-
tent of canals and rail-ways which they have executedj in
effecting these important objects, sufficiently prove, that
their exertions, during the short time they have been so
engaged, have been neither small nor ill-directed. The
aggregate length of the canals, at present in operation in
the United States alone, amounts to upwards of two thou-
sand seven hundred miles, and that of the rail-ways, already
completed, to sixteen hundred miles. Nor are the labors
of the people at an end ; for, even now, there are no few-
er than thirty-three rail-ways in an unfinished state, whose
aggregate length, when completed, will amount to upwards
of two thousand five hundred miles.
The zeal with which the Americans undertake, and the
rapidity with which they carry on, every enterprise, which
has the enlargement of their trade for its object, cannot
fail to strike all, w^ho visit the United States, as a charac-
teristic of the nation. Forty years ago, that country was
almost without a lighthouse, and now, no fewer than two
hundred are nighdy exhibited on its coast ; thirty years
ago, it had but one steamboat, and one short canal, and
now, its rivers and lakes are navigated by between five and
six hundred steamboats, and its canals are upwards of two
thousand seven hundred miles in length ; ten years ago,
there were but three miles of rail-way in the country, and
now, there are no less than sixteen hundred miles in oper-
ation." These facts appear much more wonderful, when
it is considered, that many of these great lines of commu-
nication are carried for miles in a trough, as it were, cut
300 APPENDIX.
through thick and almost impenetrable forests, where it is
no uncommon occurrence to travel for a whole clay, with-
out encountering a village, or even a house, excepting,
perhaps, a few log-huts, inhabited by persons connected
with the works.
The routes of the principal canals and rail-roads in
North America are not wholly confined to the seaward and
more thickly-peopled States, but extend far into the in-
terior. The stupendous canals, which have already been
executed, enable vessels, suited to the inland navigation
of the country, to pass from the Gulf of St. Lawrence to
the Gulf of Mexico, and also from the city of j\ew York
to Quebec, on the St. Lawrence, or to New Orleans, on
the Mississippi, without encountering the dangers of the
Atlantic ocean. But, that the reader may be able fully
to understand the nature of lines of inland navigation, so
enormous, I shall give, in detail, the route from New
York to New Orleans, which is constantly made by per
sons travelling between those places.
Miles.
From New York to Albany, by the River Hudson, the dis-
tance is, ....... . 150
♦' Albany to Buffalo, by the Erie Canal, . . . .363
♦' Buffalo to Cleveland, by Lake Erie, . ... 210
" Cleveland to Portsmouth, by the Ohie Canal, . . 309
■ ' Portsmouth to New Orl^ns, by the Ohio and Mississippi
Rivers, . 1670
Total distance, . . 2702
This extraordinary inland journey, of no less than two
thousand seven hundred and two miles, is performed en-
tirely by means of water-communication ; six hundred
and seventy-two miles of the journey are performed on
canals, and the remaining two thousand and thirty miles
of the route is river and lake navigation.
The internal improvements of the United States are
placed under the management either of the Legislatures of
the States, in which the works are situate, or of joint-
stock companies. The works constructed by the Legis-
latures of the States, are called State Works, and are
conducted by commissioners, chosen from the different
CANALS IN THE UNITED STATES. 301
Legislatures, who publish annual reports on the works
committed to their charge. The joint-stock companies,
on the other hand, are composed of private individuals,
who receive a charter from the Government, investing
them with powe'r to execute the work, and afterwards to
conduct the affairs and transact the business of the com-
pany. The public works in the British dominions in
North America have been executed, partly, at the ex-
pense, and under the direction, of the British Govern-
ment, and partly, by companies of private individuals.
It is believed that canals, which were, until very lately,
the only mode of conveyance employed in North Ameri-
ca, were in use in Egypt, China, Ceylon, Italy, and Hol-
land, before the Christian era ; but the period, at which
the first artificial water-communication w^as formed, and
the country, in which the construction of a canal was first
attempted, are equally unknown. The earliest canal con-
structed in France was the Languedoc, connecting the
Bay of Biscay with the Mediterranean Sea, w^hich was
completed in the year 1681 ; and the first formed in
Great Britain was that of Sankey Brook, in Lancashire,
completed in 1760. Several short canals were made,
for improving the river navigation, in the United States,
about the end of the last century ; but the first work of
any importance, in that countr^jr, was the Santee canal,
in the State of South Carolina, which was opened in the
year 1802 ; and the first, in the British dominions in Amer-
ica, was the Lachine canal, in Lower Canada, opened in
the year 1821. At the end of this chapter is a table of
the principal canals in the United States. The table,
which is compiled from the American a/manacs, and the
annual reports of the canal commissioners, contains the
names of all the canals of any importance, now in opera-
tion in the country ; together with such information, regard-
ing their size and expense, as these documents contain.
The great length of many of the A-merican canals is
one remarkable feature in these astonishing works. In
this respect, they far surpass any thing of the kind hith-
erto constructed in Europe. The longest canal in Eu-
rope is the Languedoc, which has a course of one hun-
II. 26 XII.
302 APPENDIX.
dred and forty-eight miles ; and the most extensive in the
United States is the Erie canal, which is no less than
three hundred and sixty-three miles in length. But the
cross-sectional area of the American canals is by no means
so great as that of many in Europe. The North Holland
Ship canal, for example, between the Zuyder Zee, at
Amsterdam, and the Holder, which I lately visited, has a
larger cross-sectional area, than any other European work
of the same description. It measures one hundred and
twenty-four feet six inches, at the water-line, and affords
sufficient breadth to allow large vessels to pass each other
with perfect ease. It is fifty-six feet in breadth, at the
bottom, and has a depth of water of no less than twenty-
one feet. This remarkable canal, which is nearly fifty
miles in length, undoubtedly ranks as one of the greatest
works of the kind that has ever been executed. It was
constructed for the purpose of facihtating the passage of
vessels to and from the port of Amsterdam ; and, by means
of the sheltered inland passage which it affords, the intri-
cate and dangerous navigation of the Zuyder Zee is avoid-
ed. At the time when canals were introduced into Amer-
ica, however, the trade of the country was small, and did
not warrant the expenditure of large sums of money in
their construction, the chief object being to form a com-
munication, with as little loss of time, or outlay of capital,
as might be consistent with a due regard for the safety and
stability of the work. It is not to be expected, therefore,
that the American works, although on an extensive scale,
should be constructed in the same spacious style as those
of older and more opulent countries. The dimensions of
many of the canals in the United States are no-w found
to be inconveniently small, for the increased traffic which
they have to support ; and the great Erie canal, as well
as some others, is at present undergoing extensive altera-
tions, by which its breadth will be increased from forty to
sixty feet, and its depth from four to seven feet. It is
doubtful whether the increased depth will, on the whole,
j)rove advantageous, especially for quick transport. Ac-
cording to Mr. Russell, the velocity of the wave due to a
depth of four feet, making allowance for the sloping sides
CANALS IN THE UNITED STATES. 303
of the canal, is about seven miles an hour ; and if the boat
is dragged in the top of the wave, the horses must travel
at somewhat more than this rate, in order to keep before
Jt. If, on the other hand, the depth of the canal be seven
feet, the velocity of the wave will be about nine miles an
hour ; a speed which it would be difficult for horses regular-
ly to keep up. The boat would, consequently, travel at
a less speed than the wave, which is shown by Mr. Rus-
sell, in his ' Researches in Hydrodynamics,' to be very
disadvantageous.
English and American engineers are guided by the
same principles in designing their works ; but the differ-
ent nature of the materials employed in their construc-
tion, and the climates and circumstances of the two coun-
tries, naturally produce a considerable dissimilarity in the
practice of civil-engineers in England and America. At
the first view, one is struck with the temporary and ap-
parently unfinished state of many of the American w^orks,
and is very apt, before inquiring into the subject, to im-
pute to want of ability what turns out, on investigation,
to be a judicious and ingenious arrangement to suit the
circumstances of a new country, of which the climate is
severe, — a country, where stone is scarce, and wood is
plentiful, and where manual labor is very expensive. It
is vain to look to the American works for the finish, that
characterizes those of France, or the stability, for which
those of Britain are famed. Undressed slopes of cut-
tings and embankments, roughly-built rubble-arches, stone
parapet-walls coped with timber, and canal-locks whol-
ly constructed of that material, every where offend the
eye accustomed to view European workmanship. But it
must not be supposed that this arises from want of knowl-
edge of the principles of engineering, or of skill to do
them justice in the execution. The use of wood, for
example, which may be considered, by many, as wholly
inapplicable to the construction of canal-locks, where it
must not only encounter the tear and wear occasioned by
the lockage of vessels, but must be subject to the destruc
tive consequences of alternate immersion in water and
exposure to the atmosphere, is yet the result of delioer-
304 APPENDIX.
ate judgement. The Americans have, in many cases,
been induced to use the material of the country, ill adapt-
ed though it be, in some respects, to the purposes to
which it is applied, in order to meet the wants of a ris-
ing community, by speedily, and perhaps superficially,
completing a work of importance, which would otherwise
be delayed, from a want of the means to execute it in a
more substantial manner ; and, although the works are
wanting in finish, and even in sohdity, they do not fail
for many years to serve the purposes for which they were
constructed, as efficiently as works of a more lasting de-
scription.
When the wooden locks on any of the canals begin to
show symptoms of decay, stone structures are generally
substituted ; and materials, suitable for their erection, are
with ease and expedition conveyed from the part of the
country where they are most abundant, by means of the
canal itself to which they are to be applied ; and thus
the less substantial work ultimately becomes the means
of facilitating its own improvement, by affording a more
easy, cheap, and speedy transport of those durable and
expensive materials, without the use of which, perfectioi
is unattainable.
One of the most important advantages of constructing
the locks of canals, in new countries, such as America,
of wood, unquestionably is, that, in proportion as improve
ment advances, and greater dimensions, or other changes,
are required, they can be introduced at little cost, and
without the mortification of destroying expensive and
substantial works of masonry. Some of the locks on
the great Erie canal are formed of stone ; but, had they
all been made of wood, it would, in all probability, have
been converted into a ship-canal, long ago.
But the locks are not the only parts of the American
canals in which wood is used. Aqueducts, over ravines
or rivers, are generally formed of large wooden troughs,
resting on stone pillars ; and even more temporary expe-
dients have been chosen, the ingenuity of which can hard-
ly fail to please those who view them as the means of
carrying on improvements, which, but for such contriv-
CANALS IN THE UNITED STATES. 305
ances, might be stopped by the want of funds necessary
to complete them.
Mr. M'Taggart, the resident engineer for the Rideau
canal in Canada, gave a good example of the extraordi-
nary expedients often resorted to, by suggesting a very
novel scheme for carrying that work across a thickly
wooded ravine, situate in a part of the country where
materials for forming an embankment, or stone for build-
ing the piers of an aqueduct, could not be obtained but
at a great expense. The plan consisted of cutting across
the large trees in the line of the works, at the level of
the bottom of the canal, so as to render them fit for sup-
porting a platform on their trunks, and on this platform the
trough containing the water of the canal was intended to
rest. I am not aware whether this plan was carried into
effect ; but it is not more extraordinary than many of the
schemes to which the Americans have resorted, in con-
structing their pubhc works ; and the great traffic sus-
tained by many of them, notwithstanding the temporary
and hurried manner in which they are finished, is truly
wonderful. The number of boats navigating the Erie
canal, in 1836, was no less than three thousand one hun-
dred and sixty-seven, and the average number of lockages,
one hundred and eighteen per day ; facts which clearly
prove the efficiency, as well as the utihty, of the work.
With the exception of some few works, in the most
southern States of the Union, the artificial navigation of
North America, as well as that of the northern rivers
and lakes, is completely suspended during a period of
from three to five months, every year. During that time,
the water is always withdrawn from the canals and feed-
ers. This precaution is absolutely necessary, as the in-
tense frost, with which the country is then visited, very
soon proves destructive to the locks and aqueducts, by
the expansion of the water, which, if permitted to re-
main in them, is speedily converted into a mass of ice.
The rate of travelling, which has been adopted on
the American canals, the charges for the conveyance of
passengers and goods, and the general laws for regulating
canal transport, are fixed by the commissioners who have
26*
306 APPENDIX.
charge of the different works, and are not exactly the
same in every State. The following observations, how-
ever, regarding the mode of travelling on the Pensylva-
nia State canals, are generally applicable to all others in
the country.
The tolls paid to the State, by the persons who have
boats on the§e canals, are three halfpence per mile for
each boat, and three farthings per mile for each passenger
conveyed in them. The passenger-boats vary from twelve
to fifteen feet in breadth, and are eighty feet in length ;
the large-sized boats weigh about twenty tons, and cost
£250 each, and, when loaded with a full complement of
passengers, draw twelve inches of w^ater. They are
dragged by three horses at once, which run ten-mile sta-
ges. The length of the tow-hne, generally used, is about
one hundred and fifty feet, and the rate of travelling is
from four to four and a half miles per hour.
The works, which have been employed in forming
the inland lines of water-communication in America, are
of two kinds, called slackwater-navigation, and canals.
The slackw^ater-navigation is the more simple of these
operations, and can generally be executed at less expense.
It consists in improving the navigation of a river by the
erection of dams, or mounds, built in the stream, which
have the effect of damming up the water, and increasing
its depth. If there be not a great fall in the bed of the
river, a single dam often produces a stagnation in the run
of the water, extending for many miles up the river, and
forming a spacious navigable canal. The tow-path is
formed along the margin of the river, and is elevated above
the reach of flood- water. The dams are passed by means
of locks, such as are used in canals. This method of
forming water-communication, has been extensively and
successfully introduced in America, where limited means,
and abundance of rivers, rendered it peculiarly applicable.
One of the most extensive works, on this principle, in the
country, was constructed by the Schuylkill Navigation
Company, in the State of Pennsylvania, and consisted in
damming up the water of the river Schuylkill. It ex-
tends from Philadelphia to Readii^, and is situate in the
CANALS IN THE UNITED STATES. 307
lieart of a country abounding in coal, from the transport
of which, the Company derives its chief revenue. It is
one hundred and eight miles in length, and its construc-
tion cost about .£500,000. This line of navigation is
formed by numerous dams thrown across the stream, with
twenty-nine locks, which overcome a fall of six hundred
and ten feet. It is navigated by boats of from fifty to
sixty tons burden. These dams are constructed some-
what on the same principle as that erected on the Schuyl-
kill, at Fairmount Water-works, near Philadelphia.
One great objection, to this mode of forming inland
navigation, is the necessity of constructing works of great
strength, sufficient to enable them to withstand the floods
and ice, to which they are exposed, and by which they are
very apt to be damaged, or even carried away. Acci-
dents of this kind, however, may be in a great measure
guarded against, by making a judicious selection of situa-
tions for the dams and locks, and placing them in such a
manner in the bed of the river, that the current may act
on them in the direction least detrimental to their sta-
bility, as has been done in the dam at Fairmount Water-
works, just alluded to.
The number of boats, which passed through the locks
of the Schuylkill navigation, in 1836, was twenty-four
thousand four hundred and seventy, the tolls on which
amounted to £14,043. The various articles taken up
the river, during that year, weighed sixty-one thousand
and seventy-nine tons, and those brought towards the sea,
five hundred and seventy thousand and ninety-four tons, of
which four hundred and thirty-two thousand and forty-five
tons were anthracite coal, from the State of Pennsylvania.
Slackwater-navigation also occurs at intervals on many
of the great lines of canal. About seventy-eight miles of
ihe Rideau canal, in Canada, are formed in this way ; and
in the United States, it is met with on the Erie, Oswego,
Pennsylvania, Frankston, Lycoming, and Lehigh canals.
The works which have been executed, in forming most
of the water-communications, in America, however, are
not generally of the slackwater kind, but resemble the
canals in use in Europe, being, in fact, artificial trenches
308 APPENDIX.
or troughs, with locks to enable vessels to pass from one
evel to another. The locks are furnished with boom--
gates, which are opened and shut by a long lever fixed to
the tops of the quoin and mitre posts. The sluices, by
which the water is admitted into the locks, are placed in
the lower part of the gates. They are, in general, com-
mon hinge-sluices, opened by means of a rod extending
to the top of the gates, and worked by a crank handle.
The canals of this construction, in the United States,
are so very numerous, and resemble each other so much,
that I do not consider it necessary to give a detailed de-
scription of the various works which have been executed
on all of them, but shall content myself with giving a briel
sketch of the Erie canal, which was the first in America,
on which the conveyance of passengers was attempted,
and is the longest canal in the world, regarding wdiich we
possess accurate information.
The Erie canal was commenced in 1817, and com-
pleted in 1825. The main line, leading from Albany, on
the Hudson, to Buffalo, on Lake Erie, measures 363
miles in length, and cost about ^1,400,000 sterling.
The Champlain, Oswego, Chemung, Cayuga, and Crook-
ed Lake, canals, and some others, join the main line,
and, including these branch canals, it measures five hun-
dred and forty-three miles in length, and cost upwards
of £2,300,000. This canal is forty feet in breadth, at
the water line, twenty-eight feet, at the bottom, and four
fpet in depth. Its dimensions have proved too small for
the extensive trade which it has to support, and workmen
are now employed in raising its banks, so as to increase
the depth of water to seven feet, and the extreme breadth
of the canal to sixty feet. The country through which
it passes, is admirably suited for canal-navigation, and
there are only eighty-four locks on the main line. These
locks are each ninety feet in length, and fifteen in breadth,
and have an average lift of eight feet two inches. The
total rise and fall is six hundred and ninety-two feet.
The tow-path is elevated four feet above the level of the
water, and is ten feet in breadth. The Erie canal begins
at Buffalo, on Lake Erie, and extends for a distance of
CANALS IN THE UNITED STATES. 309
about ten miles along the banks of Lake Erie and the
river Niagara, as far as Tonawanda creek. By means
of the slackwater-navigation, formerly described, the
channel of the Tonawanda is rendered navigable for the
distance of twelve miles, and the canal is then carried
through a deep cutting, extending seven and a half miles,
to Lockport. Here it descends sixty feet, by means of
five locks excavated in solid rock, and afterwards pro-
ceeds, on a uniform level, for a distance of sixty-three
miles, to Genesee river, over which it is carried on an
aqueduct having nine arches, of fifty feet span, each.
Eight and a half miles from this point, it passes over the
Cayuga marsh, on an embankment two miles in length, and,
in some places, seventy feet in height. It then passes
through Lakeport and Syracuse, and, at this place, the
" long level" commences, which extends for a distance
of no less than sixty-nine and a half miles, to Frankfort,
without an intervening lock. After leaving Frankfort,
the canal crosses the river Mohawk, first by an aqueduct,
of seven hundred and forty-eight feet in length, supported
on sixteen piers, elevated twenty-five feet above the sur-
face of the river, and afterwards, by another aqueduct,
one thousand one hundred and eighty-eight feet in length,
and at last reaches the city of Albany.
Albany is the capital of the State of New York, and con-
tains a population of about thirty thousand. It is situate
on the west, or right, bank of the Hudson, at the head of
the natural navigation of the river ; but some improve-
ments have been made, which enable vessels of smaP
burden to ascend as far as Waterford, thirteen miles above
Albany. One of these improvements has been efi^ected by
the erection of a dam across the Hudson, eleven hundred
feet in length, and nine feet in height, at a cost of up-
wards of ^£18,000. The lock, connected with this dam,
measures one hundred and fourteen feet in length, and
thirty feet in breadth. Albany, however, may be said
to monopolize the trade of the river, and, in addition to
the interest it possesses as a place of great commerce, it
is important from its position at the outlet of the Erie
canal, and as the seat of a large basin, or depot, for the
310 APPENDIX.
accommodation of the boats navigating it. This basin,
which has an area of thirty-two acres, is formed by an
enormous mound, placed lengthwise with the stream of
the river Hudson, and enclosing a part of its surface.
The mound is composed, chiefly, of earth, and is four
thousand three hundred feet in length, and eighty feet m
breadth, and, being completely covered with large warp-
houses, it now forms a part of the city of Albany, w^itn
which it is connected by means of numerous drawbridges
The place has, in consequence, very much the same ap-
pearance as many of the Dutch towns. The lower ex-
tremity of the mound is unconnected with the shore, ?
large passage being left for the ingress and egress of ves-
sels ; but its upper end is separated from the bank oi
the river, by a smaller opening, which is closed, when
necessary, to prevent ice from injuring the craft lying in
the basin. A stream of water is generally allowed to
enter at the upper end, which, flowing through the basin,
acts as a scour, and prevents it from silting up. The
mound is surrounded by a wooden wharf, like those of
New York and Boston, at which vessels discharge and
load their cargoes. This admirable basin forms a part
of the Erie canal works, and cost about £26,000.
According to the Report of the Canal Commissioners,
dated March, 1837, the number of boats, registered in
the Comptroller's office, as navigating the Erie canal and
its branches, was.
In 1834, . 2,585
" 1835, . 2,914 Increase, 329
" 1836, . 3,167 " 253
The total number of clearances, or trips made during
the same years, was,
In 1834, . 64,794
*' 1835, . 69,767
" 1836, . 67,270
The average number of lockages, per day, at each
lock was.
In 1834, . 95i
" 1835, . 112
" 1836. . lis
CANALS IN THE UNITED STATES. 311
The whole tonnage, transported on the canal, during
the year 1836, was 1,310,807 tons, the value of which
amounted to §67,643,343, or £13,526,868. The pro-
portion between the weight of freight, conveyed from
the Hudson to the interior of the country, and that con-
veyed from the interior of the country to the Hudson,
was in the ratio of one to five. The tolls, collected in
1836, for the conveyance of goods and passengers,
amounted to £322,867. The rates of charge, accord-
ing to which the tolls are collected, are annually changed,
to suit the circumstances of the trade, and are not the
same throughout the whole line of the canal, which ren-
ders it difficult to give a view of them. In 1836, the
passage-money from Albany to Buffalo, in the packet-
boat, w^as £S 35., being at the rate of nearly 2d. per mile ;
and in a line-boat, which is an inferior conveyance, £1
1 8s., being at the rate of one penny and two tenths per
mile. The expenditure for keeping the canal and iis
branches in repair, during 1836, w'as §410,236, or about
£82,047 ; which, taking the whole length at five hundred
and forty-three miles, gives an average of £151 per mile.
The average cost of repairs, for the six preceding years,
amounted to £136 per mile.
Before leaving the subject of canals, I must not omit
to mention the Morris canal, in the State of New Jer-
sey. This canal leads from Jersey, on the Hudson, to
Easton, on the Delaware, and connects these two rivers.
The breadth, at the water hne, is thirty-two, and at the
bottom, sixteen, feet, and the depth is four feet. It is
one hundred and one miles in length, and is said to have
cost about £600,000. It is peculiar, as being the only
canal in America, in which the boats are moved from dif
ferent levels by means of inclined planes, instead of locks ,
a construction, which was first introduced on the Duke
of Bridgewater's canal, in England. The whole rise and
fall, on the Morris canal, is one thousand five hundred
and fifly-seven feet, of w^hich two hundred and twenty-
three feet are overcome by locks, and the remaining one
thousand three hundred and thirty-four feet, by means of
twenty- three inclined planes, having an average lift of
312 APPENDIX.
fifty-eight feet each. The boats, which navigate this
canal, are eight and one half feet in breadth of beam,
from sixty to eighty feet in length, and from twenty-five
to thirty tons burden. The greatest weight ever drawn
up the planes is about fifty tons. The boat-car used on
this canal, consists of a strongly made wooden crib, or
cradle, on which the boat rests, supported on two iron
wagons running on four wheels. When the car is wholly
supported on the incHned plane, or is resting on a level,
the four axles of the wagons are all in the same plane ;
but when one of the w^agons rests on the inclined plane,
and the other on the level surface, their axles no longer
remain in the same plane, and their change of position
produces a tendency to rack the cradle, and the boat
which it supports ; but this has been guarded against, in
the construction of the boat-cars on the Morris canal, by
introducing two axles, on which the whole w^eight of the
crib and boat are supported, and on which the wagons
turn, as a centre. The cars run on plate-rails, laid on
the inclined planes, and are raised and lowered by means
of machinery driven by water-wheels. The rail-way, on
which the car runs, extends for a short distance from the
lower extremity of the plane, along the bottom of the
canal. When a boat is to be raised, the car is lowered
into the water, and the boat being floated over it, is made
fast to the part of the framework which projects above the
gunwale. The machinery is then put in motion ; and the
car, bearing the boat, is drawn by a chain to the top of
the inclined plane, at which there is a lock for its recep-
tion. The lock is furnished with gates, at both extremi-
ties ; after the car has entered it, the gates next the top
of the inclined plane are closed, and, those next the canal
being opened, the w^ater flows in and floats the boat off
the car, when she proceeds on her way. Her place is
supplied by a boat travelling in the opposite direction,
which enters the lock, and the gates next the canal being
closed, and the water run off, she grounds on the car.
The gates next the plane are then opened, the car is gen-
tly lowered to the bottom, when it enters the w^ater, and
the boat is again floated. The principal objection, urged
CANALS IN THE UNITED STATES. . 313
against the use of inclined planes, in canal navigation, for
moving boats from different levels, is founded on the in-
jury which the boats are apt to sustain in supporting great
weights, while resting on the cradle, during its passage
over the planes. It can hardly be supposed that a shm-
ly-built canal-boat, measuring from sixty to eighty feet in
length, and loaded with a weight of twenty or thirty tons,
can be grounded, even on a smooth surface, without strain-
ing and injuring her timbers ; a circumstance which is a
decided objection to this mode of construction, and has
operated powerfully in preventing its introduction in many
situations, both in this country and in America. But,
notwithstanding this objection, the twenty-three inclined
planes on the Morris canal are in full operation, and act
exceedingly well. No pains have been spared to render
the machinery connected with them as perfect as possible,
and the greatest credit is due to the engineer for the suc-
cess which has hitherto attended the operation. — Steven-
son^s ' Sketches of Civil Engineering in Mrth America.^
II. 27 XII.
314
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318 APPENDIX.
V. — Rail-ways in the United States.
Within a very (ew years, a wonderful change has been
effected in land-communication throughout Great Brit-
ain and America, where rail-ways have been more ex-
tensively and successfully introduced than in any other
parts of the world. As early as the sixteenth century,
wooden tram-roads were used in the neighborhood of
many of the collieries of Great Britain. In the year
1767, cast-iron rails were introduced at Colebrookdale, in*
Shropshire. In IS 11, malleable iron rails were, for the
first time, used in Cumberland, and the locomotive en-
gine, on an improved construction, was successfully in-
troduced on the Liverpool and Manchester line, in 1830.
Little progress has hitherto been made in the formation
of rail- ways on the Continent of Europe. A small one
has been in existence, for some time, in the neighborhood
of Lyons ; but the only rail-road, constructed in France,
for the conveyance of passengers by locomotive power,
is that from Paris to St. Germains, which was opened
only in 1837. In Bohemia, the ChevaHer Gerstner,
about eight years ago, constructed a rail-way of eighty
miles in length, leading from the river Muldau to the Dan-
ube. In Belgium, the rail-way from Antwerp to Ghent
has been in use for some time ; and some lines are at pres-
ent being constructed in Holland and Russia. But the
purpose of the present article is to describe the state of
this wonderful improvement in communication, in the
United States.
The Quincy rail-road, in Massachusetts, .was the first
constructed in America. It was intended for the con-
veyance of stone from the Quincy granite-quarries to a
shipping port, on the river Neponset, a distance of about
four miles. At the end of this article is given a tabular
list of the principal rail-roads which are already finished,
and also of those that have been begun in the United
States, which show the rapid increase of these works
since 1827, the date at which the Quincy rail-road was
completed. From these tables it appears that, in 1840,
there were no fewer than seventy-one rail-ways completed.
RAIL-WAYS IN THE UNITEL STATES. 319
and in full operation, whose aggregate length amounts to
about twenty-three hundred miles ; and also, that twenty-
three rail-ways were then in progress, which, when com-
pleted, will amount to about twenty- eight hundred miles.
In addition to this, upwards of one hundred and fifty rail-
way companies have been incorporated ; and the works
of many of them will, in all probability, be very soon
commenced.
The Boston and Lowell rail-way, in Massachusetts, is
twenty-six miles in length, and is laid with a double line
of rails. The breadth between the rails, which is four
feet eight and a half inches, is the s.ame in all the Ameri-
can rail-roads, and the breadth between the tracks is six
feet.
The supporters are granite blocks, six feet in length,
and about eighteen inches square. These are placed
transversely, at distances of three feet apart, from centre
to centre, each block giving support to l30th of the rails.
This construction was first introduced in the Dublin and
Kingstown rail-way, in Ireland, but was found to pro-
duce so rigid a road, that great difiiculty was experienced
in securing the fixtures of the chairs. From the difficulty,
also, of procuring a solid bed for stones of so great di-
mensions, most of them, after being subjected for a short
time to the traffic of the rail-way, were found to be split.
Another construction has been tried on this line, con-
sisting of longitudinal trenches, two feet six inches
square, and four feet eight and a half inches apart, from
centre to centre, formed in the ground, and filled with
broken stone, hard punned down with a wooden beater,
as a foundation for the stone blocks on which the rails
rest. These blocks measure two feet square, and a foot
in thickness, and a transverse sleeper of wood, two feet
eight inches and a half in length, one foot in breadth, and
eight inches in th'ckness, is placed between the blocks,
to prevent them from moving.
The plan of resting the rail-way on a foundation of brok
en stone was adopted, in the expectation that it might be
sunk to a sufficient depth below the surface of the ground,
to prevent the frost from affecting it ; bat subsequent
320 APPENDIX.
experience has shown that many of those rail-ways, whose
construction was more superficial, have resisted the ef-
fects of frost much better.
The New York and Patterson rail-way is sixteen and
a half miles in length, and extends along a marshy tract
of ground. The foundation of the road consists of a
line of pits under each rail, eighteen inches square,. and
three feet in depth. They are placed three feet apart,
from centre to centre, and filled with broken stones. On
this foundation, transverse wooden sleepers, measuring
eight inches square, and seven feet in length, are firmly
bedded, on w^hich rest the longitudinal sleepers, measur-
ing eight inches by six. To these, plate-rails of mallea-
ble iron, two and a half inches wide, and half an inch
thick, weighing about thirteen pounds per lineal yard, are
fixed by iron spikes.
In the Saratoga and Schenectady rail-way, the paral-
lel trenches are eighteen inches square, and four feet
eight and a half inches apart, from centre to centre. They
extend throughout the whole line of the rail-way, and are
firmly punned full of broken stones. Longitudinal sleep-
ers of wood, measuring eight by five inches, are placed
on these trenches, which support the transverse wooden
sleepers, measuring six inches square, and placed three
feet apart, from centre to centre. Longitudinal runners,
measuring six inches square, are firmly spiked to the
transverse sleepers, and the whole is surmounted by a
plate-rail, half an inch thick, and two and a half inches
wide, weighing about thirteen pounds per lineal yard.
The Newcastle and Frenchtown rail- way, which is
sixteen miles in length, and forms part of the route from
Philadelphia to Baltimore, is constructed in the same way
as that between Schenectady and Saratoga, excepting
that the plate-rail is two and a half inches broad, and five
eighths of an inch thick, and weighs nearly sixteen pounds
per lineal yard. The Baltimore and Washington rail-
way is also constructed in the same manner, as regards the
foundation and arrangement of the timbers ; but edge-rails
are employed on that line, three and a half inches in
breadth at the base, and two inches in height.
RAIL-WAYS IN THE UNITED STATES. 321
Several experiments have been made on the Columbia
rail-road, in Pennsylvania, which is eighty-two miles in
length, and is under the management of the State. Part
of the road is constructed with trenches measuring two
feet six inches in breadth, and two feet in depth, excava
ted in the ground, and filled with broken stone. In these,
the stone blocks, two feet square, and a foot in thickness,
are imbedded, at distances of three feet apart, to which
the chairs and rails are spiked, in the ordinary manner.
The rails on each side of the track are connected togeth-
er by an iron bar. This attachment is rendered absolute-
ly necessary, on many parts of the Columbia rail-road,
by the sharpness of the curves, which, at the time when
the work was laid out, were not considered so prejudicial
on a rail-way, as experience has shown them to be.
Another plan tried on this road has a continuous line ot
stone curb, one foot square, resting on a stratum of broken
stone, instead of the isolated stone blocks. A plate-rail,
half an inch thick, and two and a half inches broad, is
spiked down to treenails, of oak or locust wood, driven
into jumper-holes bored in the stone curb.
The Boston and Providence rail-way is forty-one miles
in length. Pits, measuring eighteen inches square, and
one foot in depth, are excavated under each hne of rail,
at intervals of four feet apart. They are filled with broken
stone, and form a foundation for the transverse wooden
sleepers, measuring eight inches square, on which the
chairs and rails are fixed in the usual manner.
One of the tracks, in very general use in America, is
met with on the Philadelphia and Norristown. the New
York and Haerlemand the Buffalo and Niagara rail-roads ;
and has been mtroduced on many others. It consists
of two lines of longitudinal wooden runners, measuring
one foot in breadth, and from three to four inches in
thickness, bedded on broken stone, or gravel. On these
^runners, transverse sleepers are placed, formed of round
timber, with the bark left on, measuring about six inches
in diameter, and squared at the ends, to give them a prop-
er rest. Longitudinal sleepers, for supporting the rails,
are notched into the transverse sleepers. The rail is flat.
322 APPENDIX.
made of wrought-iron, and varies in weight from ten to fif-
teen pounds per lineal yard. It is fixed down to the sleep-
ers, at every fifteen or eighteen inches, by spikes four or
five inches in length, the heads of which are countersunk
in the rail.
The rails used on the Camden and Amboy rail-way,
w^hich is sixty-one miles in length, are parallel edge-rails,
and are spiked to transverse sleepers of wood, and, in
some places, to w^ood treenails driven into stone blocks.
Their breadth is three and a half inches at the base, and
two and a half at the top, and their height is four inches.
They are formed in lengths of fifteen feet, and secured at
the joints by an iron plate on each side, with two screw-
bolts passing through the plates and rails. On the Phila-
delphia and Reading rail-road, rails of the same form
have been adopted.
On several of the rail-roads, with a view to counteract
the effects of frost, round piles of timber, about twelve
inches in diameter, are driven into the ground as far as
they will go, at the distance of three feet apart, from cen-
tre to centre. The tops are cross-cut, and the rails are
spiked to them in the same way as in the Camden and
Amboy Rail-way. The heads of the piles are furnished
with an iron strap, to prevent them from splitting ; and
the rails are connected together, at every five feet, by an
iron bar.
The Brooklyn and Jamaica rail-road is exceedingly
smooth, and is said to resist the effects of frost very suc-
cessfully. It consists of transverse sleepers, measuring
eight by six inches, supported on slabs of pavement, two
feet square, and six inches thicli. The wooden runner
;s spiked on the inside of the chairs, to render tnem firm
This rail rests on the cheeks^ or sides, of tne cnair, ana
not on the bottom, as is generally the case.
The rail-road between Charleston and Augusta, and
many others in the southern States, where there is a scar-
city of materials for forming embankments, are carried
over low-lying tracts of marshy ground, elevated on struc-
tures of wooden truss-work. The framing is nsed in sit-
uations where the level of the rails does not require to be
RAIL-WAYS IN THE UNITED STATES. o2o
raised more than ten or twelve feet above the surface of
the ground. Piles, from ten to fifteen inches in diameter,
are driven into the ground by a piling engine, and, in
places where the soil is soft, their extremities are not
pointed, but are left square, which makes them less liable
to sink under the pressure of the carriages. The struts
are attached to the tops of the piles, and are also fixed
i*> dwarf piles driven into, the ground. Their effect is to
prevent lateral motion. It is evident, however, that these
structures are by no means suitable or safe, for bearing
the weight of locomotive engines or carriages ; and, as
may naturally be expected, very serious accidents have
ocjasionally occurred on them. They are, besides, gen-
erally left quite exposed, and, in some situations, when
they are even so much as twenty feet high, no room
is left for pedestrians, who, if overtaken by the en-
gine, can save themselves only by making a leap to the
ground.
These varieties of construction were all in use in the
United States in 1837 ; but the American engineers had
not, at that time, come to any definite conclusion, as to
which of them constituted the best rail-way. It seemed
to be generally admitted, however, that the wooden struc-
tures were, in most situations, more economical than those
formed of stone, and were also less liable to be affected
by the frost. Structures of wood also possess a great
advantage over those of stone, from the much greater ease
with which the rails supported by them are kept in repair.
Wooden rail-roads are more elastic, and bend under great
weights, while the rigid ana unyielding nature of the rail
roads laid on stone blocks causes the impulses, producec
oy the rapia motion of locomotive carriages, or heavily
loaded wagons, over the surface, to be much more severe-
ly felt, both by the machinery of the engine, and by the
rails themselves. Experience, both in this country and
in America, has shown the truth of these remarks. On
the Liverpool and Manchester rail-way, for example, on
which a large sum is annually expended in keeping the rails
in order, the part of the road which requires least repair
!s that extending over Chat Moss, where the rails are laid
324 APPENDIX.
on wooden sleepers, and the weight of passing trains ol
loaded wagons produces a sensible undulation in the sur-
face of the rail-way, which at this place actually floats on
the moss. These considerations are worthy of attention ;
and, since the introduction of Kyan's patent anti-dry-rot
preparation, wood is beginning to be more generally em-
[)loyed for the construction of rail-ways in this country.
The rails of the Dublin and Kingstown road are now laid
on wood, and it has also been extensively employed on the
Great Western rail-way, now in progress.
The rails used in the United States are of British man-
ufacture. They are often taken to iVmerica as ballast ;
and the Government of the United States having remov-
ed the duty from iron imported for the purpose of forming
rail-ways, the rails are laid down on the quays of New York
nearly at the same cost, as in any of the ports of Great
Britain. Those of the Brooklyn and Jamaica road, which
are in lengths of fifteen feet, and weigh thirty-nine pounds
per lineal yard, are of British manufacture, and cost at New
York, when they were landed, in 1836, £S per ton ; the
cast-iron chairs, which are also of British manufacture,
weigh about fifteen pounds each, and cost <£9 per ton.
There is a great abundance of iron ore in America, and
some of the veins in the neighborhood of Pittsburg are at
present pretty extensively worked ; but the Americans
know that it would be bad economy to attempt to manufac-
ture rails, so long as those made at Merthyr Tydvil Iron-
works, in Wales, can be laid down at their sea-ports at
the present small cost.
The stone blocks, in use on some of the rail-wavs. are
inade of granite, which is found in many parts of the
United States. Yellow pine is generally employed for
tne longitudinal sleepers, and cedar, locust, or white-oaK,
for the transverse sleepers on which the rails rest. Cedar,
however, if it can be obtained, is generally preferred for
the transverse sleepers, because it is not liable to be split
by the heat of the sun, and is less affected than perhaps
any other timber, by dampness and exposure to the at-
mosphere. The cedar sleepers used on the Brooklyn
and Jamaica rail-way, measuring six inches by five, and
RAIL-WAYS IN THE UNITED STATES. 325
seven feet in length, notched, and in readiness to receive
the rails, cost ^s. S^d. each, laid down at Brooklyn. It
is a costly timber, and is not very plentiful in the United
States. It has also risen greatly in value, since the intro-
duction of rail-ways, for the construction of which it is
peculiarly applicable. For all treenails, locust-wood is
universally employed.
The American rail-roads are much more cheaply con-
structed than those in England, which is owing chiefly to
three causes ; firsts they are exempted from the heavy
expenses often incurred in the construction of English rail-
ways, by the purchase of land, and compensation for dam-
ages ; second, the works are not executed in so substantial
and costly a style ; and, third, wood, which is the prin-
cipal material used in their construction, is got at a very
small cost. The first six miles of the Baltimore and
Ohio rail-road, which is formed "in an expensive man-
ner, on a very difficult route," has cost, on an average,
about £12,000 per mile. The rail-roads in Pennsylva-
nia cost about £5000 per mile ; the Albany and "Sche-
nectady rail-road, upwards of £6000 per mile ; the Sche-
nectady and Saratoga rail- way, £1800 per mile ; and the
Charleston and Augusta rail-road, about the same.* Mr.
Moncure Robinson, in a report relative to the Philipsburg
and Juniata rail-road, states, that the first ten miles of
the Danville and Pottsville rail-road, formed for a double
track, but on which a single track only was laid, cost, on
an average, £4400 per mile, and that the Honesdale and
Carbondale rail-road, sixteen and one third miles in length,
laid with a single track, and executed for a considerable
Dortion of its length on truss-work, is understooa, wiin
niacnmery, to have averaged £3600 per mile. The
average cost of these rail-ways, constructed m diflx;renk
parts of the United States, is £4942 per mile.
This contrasts, strongly, with the cost of the rail-ways
constructed in Great Britian. The Liverpool and Man-
chester rail-way cost £30,000 per mile ; the Dublin and
* Facts and suggestions relative to the New York and Albany rail
way. New York, 1833.
II. 28 XII.
326
APPENDIX.
Kingstown, £40,000 ; and the rail- way between Liverpod
and London is expected to cost upwards of £25,000.
The following extract, embodying an estimate from Mr.
Robinson's Report, will give some idea of the cheapness
with which many of the American works are construc-
ted : —
" The following plan," says Mr. Robinson, '-is pro-
posed for the superstructure of the Philipsburg and Juni-
ata rail-road.
" Sills of white or post oak, seven feet ten inches long,
and twelve inches in diameter, flattened to a width of
nine inches, are to be laid across the road, at a distance
of five feet apart, from centre to centre. In notches
formed in these sills, rails of white-oak or heart-pine, tive
inches wide by nine inches in depth, are to be secured,
four feet seven inches apart, measured within the rails.
On the inner edges of these rails, plates of rolled iron,
two inches wide by half an inch thick, resting at their
points of junction on plates of sheet iron, one twelfth of
an inch thick and four and a half inches long, are to be
spiked, with five-inch wrought-iron spikes. The inner
edges of the wooden rails to be trimmed slightly level-
ling, but flush at the point of contact with the iron rail,
and to be adzed down, outside the iron, to pass off rain-
water.
" Such a superstructure, as that above described, would
be entirely adequate to the use of locomotive engines of
from fifteen to twenty horses' power, constructed without
surplus weight, or similar to those now in use on the little
Schuylkill rail-road in this State. (Pennsylvania,) or tne
Petersburg rail-road m Virgmia : and it will be observea
mat only tlie sills, which constitute but a very slight item
in its cost, are much exposed to the action of those causes
which induce decay in timber. It is particularly recom-
mended for the Philipsburg and Juniata rail-road, by the
great abundance of good materials, along the line of the
improvement, for its construction, and the consequent
economy wuth which it may be made.
" The following may be deemed an average estimate
of the cost of a mile of superstructure, as above described.
RAIL-WAYS IN THE UNITED STATES. 327
1056 trenches, 8 feet long, 12 inches wide, and 14 inches Uolls.
deep, filled with broken stone, at 25 cents each, . 264
Same number of sills, hewn, notched, and imbedded, at
50 cents each, ....... 528
10,912 lineal feet of rails, (allowing 33^ per cent, for
waste,) at 4 cents per lineal foot, delivered, . . 436.43
2112 keys, at 2^ cents each, 52.80
10,560 lineal feet of plate rails, 2 inches by ^ inch, weight
3^ lb. per foot, ISy'^^g- tons, delivered at 50 dollars
(£10) per ton, 785 50
1509 lbs. of 5-inch spikes, at 9 cents per pound, . . 135 81
Sheet iron under ends of rails, ..... 30.21
Placing and dressing wood, and spiking down iron rails, 280
Filling between sills with stone, or horse-path, . . 180
2692 dollars, or about £540. , 2692.80
It was found rather difficult to obtain much satisfactory
information regarding the expense of upholding the Amer-
ican rail-ways. It is stated in a report made by the Di-
rectors of the Boston and Worcester rail-road, that Mr.
Fessenden, their engineer, estimates the annual expendi-
ture for repairing the road, carriages, and engines, and pro-
viding fuel and necessary attendance for forty-three and a
half miles of rail-way, at £6829 per annum, which is at the
rate of £157 per mile. The expense of the repairs on the
Utica and Schenectady rail-road, which is about seventy-
seven miles in length, amounts to £23,000 per annum, be-
ing at the rate of about £363 per mile. These sums for
keeping rail-roads in repair are exceedingly small, compar-
ed with the amount expended in this country for the same
purpose. On the Liverpool and Manchester rail-way, for
example, the expense annually incurred, in keeping the
engines in a working state, and the rail-wav in repair.
amounts to upwards of £30,000, or £1000 per miJt^
This difference in the cost arises, m a a^reat measure, iron,
tne comparatively slow speed at which the engines work-
ing on the American rail-ways are propelled, which, in the
course of my own observation, never exceeded the aver-
age rate of 6fteen miles per hour. On the State rail-ways,
and also on many of those under the management of in-
corporated companies, fifteen miles an hour is the rate of
travelling fixed by the administration of the rail-way, and
•his speed is seldom exceeded.
328 APPENDIX.
On some of the American rail-ways, where the line is
short, or the traffic small, horse power is employed ; but
locomotive engines for transporting goods and passen-
gers, are in much more general use. In New Ycrk,
Brooklyn, Philadelphia, Baltimore, and other places,
which have lines of rail-way leading from them, the depot,
or station for the locomotive engines, is generally placed
at the outskirts, but the rails are continued through the
streets, to the heart of the town, and the carriages are
dragged over this part of the line by horses, to avoid the
inconvenience and danger, attending the passage of loco-
motive engines, through crowded thoroughfares.
The fuel used on most of the rail-ways is wood, but
the sparks vomited out by the chimney are a source of
constant annoyance to the passengers, and occasionally
set fire to the wooden bridges on the line, and the houses
in the neighborhood. Anthracite coal, as formerly no-
ticed, has been tried, but the same difficulties which at-
tend its use in steam-boat furnaces, are experienced, to
an equal extent, in locomotive engines.
In situations where the summit-level of a rail-way can-
not be attained, by an ascent sufficiently gentle for the
employment of locomotive engines, or where the forma-
tion of such inclinations, though perfectly practicable,
would be attended with an unreasonably large outlay,
transit is generally effected by means of inclined planes,
worked by stationary engines. This system has been
introduced on the Portage rail-way, over the Alleghany
Mountains, in America, on a more extensive scale, than
in any other part of the world. The Portage or Alle-
ghany rail-way forms one of tiie links of the great Penn
sylvania canal and rail-road communication, from Phila-
delphia to Pittsburg, — a work ot so difficult and vast a
nature, and so pecuhar, both as regards its situation and
details, that it cannot fail to be interesting to every engi-
neer, and I shall, therefore, state at some length the
facts which I have been able to collect regarding it.
This communication consists of four great divisions, the
Columbia rail-road, the Eastern Division of the Penn-
sylvania canal, the Portage or Alleghany railroad, and
RAIL-WAYS IN THE UNITED STATES. 329
the Western Division of the Pennsylvania canal. These
works form a continuous line of communication from Phil-
adelphia, on the Schuylkill, to Pittsburg, on the Ohio, a
distance of no less than three hundred and ninety-five miles.
Commencing at Philadelphia, the first Division of this
stupendous work is the Philadelphia and Columbia rail-
road, which was opened in the year 1S34. It is eighty-
two miles in length, and was executed at a cost of about
£666,025, being at the rate of £8122 per mile. There
are several viaducts of considerable extent on this rail-way,
and two inclined planes worked by stationary engines.
One of these inclined planes is at the Philadelphia end
of the line. It rises at the rate of one in 14.6 for two
thousand seven hundred and fourteen feet, overcoming an
elevation of one hundred and eighty-five feet. The other
plane, which is at Columbia, rises at the rate of one in
21. '2 for a distance of one thousand nine hundred and
fourteen feet, and overcomes an elevation of ninety feet.
A very large sum is expended in upholding the inclined
planes, and surveys have lately been made with a view
to avoid them. The cost of maintaining the stationary
power, and superintendence of the Philadelphia inclined
plane, is said to be about £8000 per annum, and that of
the Columbia plane, about £3498 per annum. Locomo-
tive engines are used between the tops of the inclined
planes. The steepest gradient on that part of the line is
at the rate of one in one hundred and seventeen ; but
the curves are numerous, and many of them very sharp,
the minimum radius being so small as three hundred and
fifty feet. This line of rail-way was surveyed and laid
out, before the application of locomotive power to rail- way
conveyance had attained its present advanced state, — at
a period when sharp curves and steep gradients were not
considered so detrimental to the success of rail-ways, as
experience has since shown them to be.
The passenger-carriages on the Columbia rail-road are
extremely large and commodious. They are seated for
sixty passengers, and are made so high in the roof, that
the tallest person may stand upright in them, without in-
convenience. There is a passage between the seats ex-
28*
330 APPENDIX.
tending from end to end, with a door at both extremities '
and the coupling of the carriages is so arranged, tha*
the passengers may walk from end to end of a whole
train, without obstruction. In winter, they are heated by
stoves. The body of each of these carriages measures
from fifty to sixty feet in length, and is supported on two
four-wheeled trucks, furnished with friction-rollers, and
moving on a vertical pivot, in the manner formerly alluded
to, in describing the construction of the locomotive en-
gines. The flooring of the carriages is laid on longitudinal
beams of wood, strengthened with suspension-rods of iron.
At the termination of the rail-way at Columbia, is the
commencement of the Eastern Division of the Pennsyl
vania canal, which extends to HolHdaysburg, a town s'lU
uate at the foot of the Alleghany Mountains. This
canal is rather more than one hundred and seventy-two
miles in length, and was executed at an expense of
£918,829, being at the rate of <£5342 per mile. There
are thirty-three aqueducts, and one hundred and eleven
locks, on the line, and the whole height of lockage is
585.8 feet. A considerable part of this canal is slack-
water-navlgatlon, formed by damming the streams of the
Juniata and Susquehanna. The canal crosses the Sus-
quehanna at its junction with the Juniata, at which point
it attains a considerable breadth. x\ dam has been erec-
ted in the Susquehanna, at this place, and the boats are
dragged across the river by horses, which walk on a tow-
path attached to the outside of a wooden bridge, at a lev-
el of, about thirty feet above the surface of the water.
HolHdaysburg is the western termination of the East-
ern Division of the Pennsylvania canal. The town
stands at the base of the Alleghany Mountains, which ex-
tend in a southwesterly llrectlon, from New Brunswick,
to the State of Alabama, a distance of upwards of eleven
hundred miles, presenting a formidable barrier to commu-
nication between the eastern and western parts of the
United States. The breadth of the Alleghany range va-
ries from a hundred to a hundred and fifty miles, but the
peaks of the mountains do not attain a greater height than
four thousand feet above the medium level of the sea.
RAIL-WAYS IN THE UNITED STATES. 331
They rise with a gentle slope, and are thickly wooded
to their summits. " The Alleghany Mountains present
what must be considered their scarp, or steepest side,
to the east, where granite, gneiss, and other primitive
rocks, are seen. Upon these repose, first, a thin forma-
tion of transition rocks dipping to the westward, and next,
a series of secondary rocks, including a very extensive
coal formation."* The National road, which has al-
ready been noticed, was the first line of communication
formed by the Americans over tliis range ; and in the
year 1831, an Act was passed for connecting the Eastern
and Western Divisions of the Pennsylvania canal, by
means of a rail-road. This important and arduous work,
which cost about £526,871, was commenced within the
same year in which the Act for its construction was grant-
ed, and the first train passed over it on the 26th of Novem-
ber, 1833 ; but it was not till 1835, that both the tracks
were completed, and the rail-way came into full operation.
The rail-way crosses the mountains by a pass called
*' Blair's Gap," where it attains its summit-level, which is
elevated two thousand three hundred and twenty-six feet
above the mean level of the Atlantic ocean. Mr. Robin-
son surveyed a line of rail-way from Philipsburg to the
river Juniata, which is intended to cross the Alleghany
Mountains by the pass called " Emigh's Gap." The
summit-level of this line is stated, in a report by the di-
rectors, to be two hundred and ninety-two feet lower than
that of the Portage rail- way.
The preliminary operation of clearing a track for the
passage of the rail-way, from a hundred to a hundred and
fifty feet in breadth, through the thick pine forests with
which the mountains are clad, was one in which no small
difiiculties were encountered. This operation, which is
called grubbing, is litde know^n in the practice of engi-
neering in this country, and is estimated by the Ameri-
can engineers, in their various rail- w^ay and canal reports,
at from £40 to £80 per mile, according to the size and
quantity of the timber to be removed ; an estimate which,
from the appearance of American forests, must, in many
* Encyclopaedia Britannica, article America.
332 APPENDIX.
instances, be much too low. The timber removed from
the line of the Alleghany rail-way is chiefly spruce and
hemlock pine, of very large growth.
The line is laid with a double track, or four single lines
of rails, and is twenty-five feet in breadth. For a con-
siderable distance, the rail-way is formed by side-cutting
along steep sloping ground, composed of clay-slate, bitu-
minous coal, and clay, part of the' breadth of the road be-
ing obtained by cutting into the hill, and part by raising
embankments, protected by retaining walls of masonry.
The rail-way is consequently liable to be deluged, or even
entirely swept away, by mountain torrents, and the thor-
ough drainage of its surface has been attended with great
expense and difficulty. The retaining walls,- by which
the embankments are supported, are in some places not
less than a hundred feet in height ; they are built of dry-
stone masonry, and have a batter of about one half to
one, or six inches horizontal to twelve inches perpendic-
ular. There are no parapet or fence walls on the rail-
way, and on many parts of the line, especially at the tops
of several of the inclined planes, the trains pass within
three feet of precipitous rocky faces, several hundred
feet high, from which the large trees, growing in the ra-
vines below, almost resemble brushwood. One hundred
and fifty-three drains and culverts, and four viaducts, have
been built on the rail-way. One of the viaducts crosses
the river Conemaugh, at an elevation of seventy feet above
the surface of the water. There is also a tunnel on the
line nine hundred feet in length, twenty feet in breadth,
and nineteen feet in height.
The inclined planes are, however, the most remarka-
ble works which occur on this line. The rail- way extends
from Hollidaysburg on the eastern base, to Johnstown on
the western base, of the Alleghany Mountains, a distance
of thirty-six miles ; and the total rise and fall, on the whole
length of the line, is 2571.19 feet. Of this height, 2007.02
feet are overcome by means of t^n inclined planes, and
564.17 feet by the slight inclinations given to the parts
of the railway which extend between these planes. The
distance from Hollidaysburg to the summit-level is about
RAIL-WAYS IN THE UNITED STATES. 333
ten miles, and the height is 1398.31 feet. The distance
from Johnstown to the same point is about twenty-six
miles, and the height 1172.88 feet. The height of th?
summit-level of the rail-way, above the mean level of the
Atlantic, is 2326 feet.
The machinery by which the inclined planes are work
ed consists of an endless rope passing round horizontal,
grooved wheels, placed at the head and foot of the planes
which are furnished with a powerful break, for retarding
the descent of the trains. The ropes were originall}'
made seven and a half inches in circumference, but they
have lately been increased to eight inches, to prevent a
tendency, which the)' formerly had, to slip in the grooved
wheels, occasioned by their circumference being too small
for the size of the groove, or hollow in the wheel. Two
stationary engines, of twenty-five horses' power each, are
placed at the head of the inclined planes, one of which is
in constant use in giving motion to the horizontal wheels
round which the rope moves, while the trains are passing
the inclined planes. Two engines have been placed ar
each station, that the traffic of the rail-w^ay may not be
stopped, should any accident occur to the machinery of
that which is in operation ; and they are used alternately,
for a week at a time. Water for supplying the boilers
has been conveyed, at a great expense, to many of the sta-
tions, in wooden pipes upwards of a mile in length.
The planes are laid with a double track of rails, and an
ascending and a descending train are always attached to
the rope at the same time. Many experiments have been
made, to procure an efficient safety-car, to prevent the
trains from running to the foot of the inclined plane, in
the event of the fixtures, by which they are attached to
to the endless rope, giving way. Several of these safety-
cars are in use, and are found to be a great security. The
trains are attached to the endless rope simply by two ropes
of smaller size made fagt to the couplings of the first and
last wagons of the train, and to the endless rope by a
hitch or knot, formed so as to prevent it from slipping.
Locomotive engines are used on the parts of the road
between the inclined planes. — Stevenson^ s ' Sketch of
Civil Engineering in J^orth America.''
334
APPENDIX,
Table of the Principal Rail-ways in operation in the
United States, in 1840.
NAME.
counsE.
When
Length
Whole
length
a.
opened
Miles.
in each
State.
Maine.
Bangor and Orono, .
From Bangor to Orono,
1836
10
10
New Hampshire.
Nashua and Lowell,
Nashua to Lowell,
Massachusetts.
1838
15
1
15 !
Quincy,
C Quincy Quarries to Nepon-
l set River, .
J 1827
4
Boston and Lowell, .
Boston to Lowell, .
1835
26
Andovcr and Wilmington,
C Andover to the Boston and
I Lowell Rail-road,
|l836
n
Andover and Haverhill,
Andover to Haverhill, .
1838
10
Boston and Providence,
Boston to Providence,
1835
41
Dedham Branch, .
C Boston and Providence R.
\ Road to Dedham, .
|l835
2
Taunton Branch,
C Boston and Providence
I Rail-road to Taunton,
1 1836
11
Boston and Worcester,
Boston to Worcester, .
1835
45
Western Rail-way, .
Worcester to Springfield,
1839
54
Worcester and Norwich,
Worcester to Norwich,
1839
59
Eastern Rail-road,
Boston to Newburyport,
1839
36
2951
Rhode Island.
Providence & Stonington,
Providence to Stonington,
1837
47
47
Connecticut.
Hartford and New Haven,
Hartford to New Haven,
1839
40
Housatonic,
Bridgeport to New Milford,
• •
40
New York.
80
1 Mohawk and Hudson,
C Between the Rivers Mo-
l hawk and Hudson, .
|l832
16
Saratoga & Schenectady,
Saratoga to Schenectady,
1832
22
Rochester, .
Rochester to Carthage,
1833
3
Ithaca and Oswego,
Ithaca to Oswego, .
1834
29
1 Rensselaer and Saratoga,
Troy to Ballston,
1835
24^
iUtica and Schenectady,
Utica to Schenectady, .
1836
77
j Buffalo and Niagara, .
Buffalo to Niagara Falls,
1837
21
'Haerlem,
New York to Haerlem,
1837
7
iLockport and Niagara,
Lockport to Niagara Falls,
1837
24
i Brooklyn and Jamaica,
Brooklyn to Jamaica,
1837
12
JAuburn and Syracuse,
Auburn to Syracuse,
. .
26
jCatskill and Canajoharie,
Catskill to Canajoharie,
68
Hudson and Berkshire,
C Hudson to the Boundary of
I Massachusetts,
i'
30
Tonawanda,
Rochester to Attica,
45
404^
New Jersey.
Camden and Amboy,
Camden to Amboy,
1832
61
Paterson, .
Paterson to Jersey, .
1834
16i
1 New Jersey, .
C Jersey City to New Bruns-
l wick,
Morristown to Newark,
jl836
31
Morris and Essex,
. .
20
PennsylvanA..
128i
jColumbia, .
Philadelphia to Columbia,
.
82
Alleghany, ...
CHollidaysburg to Johns-
\ town, over the Alleghanies,
}• •
36
Mauch Chunk, .
C Mauch Chunk to the Coal-
l mines, ....
J 1828
5
Room Run, .
Mauch Chunk to the mines,
Carried forward,
■ ■
5k
128i
1980*
RAIL-WAYS IN THE UNITED STATES.
335
NAME.
COURSE.
When
Length
in
Whole
length
opened
Miles.
in each
State.
Brought forward,'"
■• .
12Si
960J
Pennsylvania, contirf^ed.
Mount Carbon, .
MountCarbon to the mines, 1830
7^
Schuylkill Valley, .
(Port Carbon to Tuscarora,' )
I with numerous branches, 5 " *
30
Schuylkill, .
13
Mill Creek, . .
Port Carbon to Mill Creek,
,
7
xMinehill and Schuylkill,
20
Pine-grove,
Pine-grove to Coal-mines,
4
Little Schuylkill, .
Port Clinton to Tamaqua,
isai
23
Lackawaxen,. .
C Lackawaxen Canal to the
I River Lackawaxen,
I- •
16J
Westchester,
C Westchester to Columbia
I Rail-road, .
h832
9
Philadelphia and Trenton,
Philadelphia to Trenton,
1833
26i
Philadelphia&Norristown
Philadelphia to Xorristown
1837
19
Central Rail-way,
Pottsville to Danville,
51J
Philadelphia and' Reading,
Philadelphia to Reading,
• •
40 i
Philadelphia & Baltimore,
Philadelphia to Baltimore,
93
489
Delaware.
Newcastle & Frenchtown,
Newcastle to Frenchto^m,
1832
16
16
Maryland.
Baltimore and Ohio,
C Completed to Harper's
I Ferry, with branches,
J 1835
86
Winchester,
C Harper's Ferry to Win-
l Chester,
30
Baltimore & Port-Deposit,
Baltimore to Port-Deposit,
34i
Baltimore & Washington,
Baltimore to Washington,
i83.5
40
Baltimore & Susquehanna,
Baltimore to York, .
Virginia.
(Richmond to Chesterfield
( Coal-mines, .
1837
59i
249*
Chesterfield,
13
Petersburg and Roanoke,
( Petersburg to Blakely, on
I the Roanoke, .
59
Winchester and Potomac,
(Winchester to Harper's
\ Ferry, ....
Portsmouth to Weldon,
30
Portsmouth and Roanoke,
T7i
Richmond, Fredericks- ?
burg, and Potomac, j
(Richmond to Fredericks-
l burg, ....
58
Manchester,
Richmond to Coal-mines,
South Carolina.
13
250i
South Carolina Rail-road,
( Charleston to Hamburg on
I the Savannah,
Georgia.
|l833
136
136
Alatamaha «fe Brunswick,
Alatamaha to Brunswick,
• •
12
12
Alabama.
Tuscumbia and Decatur,
( Mussel-Shoals, Tennessee
I River,
Louisiana.
46
46
Pen tchar train,
( New Orleans to Lake Pont-
\ chartrain.
|l831
5
Carrollton,
New Orleans to Carrollton,
Kentucky.
'
6
11
Lexington and Ohio, .
Lexington to Frankfort,
29
Frankfort and Louisville,
1
Frankfort to Louisville,
Total length in miles,
50
79
2270
S36
APPENDIX.
List of the other Rail-ways now in progress in ths
United States.
Haverhill and Exeter,
Newburyport and Ports-
mouth,
Old Colony,
Western,
Western, .
Long Island,
New York and Erie,
Saratoga and Washington,
Elizabethtown&Belvidere
Burlington &Mount Holly.
Oxford,
Tioga,
Greensville and Roanoke,
Charleston and Cincinnati,
Augusta and Athens, .
Macon and Forsyth,
Central Rail-road,
Montgomery and Chat- i
tahoochee, . . . '
Mississippi Rail-road. .
Bowling Green and Bar- )
ren River, . . >
Mu-i River and Lake Erie,
Sandusky & Monroeville,
Detroit and St. Joseph,
New Hampshire.
Haverhill to Exeter,
Newburyport to Portsmouth, .
Massachusetts.
Taunton to New Bedford,
Springfield to New York line, .
Connecticut.
Hartford to Springfield,
New York.
Jamaica to Greenport,
New York to Lake Erie,
Saratoga to Whitehall,
New Jersey.
Elizabethtown to Belvidere,
Burlington to Mount Holly, .
Pennsylvania.
Columbia Rail-road to Port Deposit,
Chemung Canal to Tioga Coal-mines,
Virginia.
South Carolina.
Charleston to Cincinnati, .
Georgia.
Augusta to Athens, . . . .
Macon to Forsyth, ....
Savannah to Macon, . . . .
Alabama.
Mississippi.
Natchez to Canton,
Kentucky.
Bowling Green to Barren Biver, .
Ohio.
Dayton to Sandusky, ....
Sandusky to Monroeville,
Michigan.
Detroit to the River St. Joseph,
Total length,
MANUFACTURE OF MAPLE SUGAR. 337
VI. — Manufacture of Maple Sugar.
The following account of the manufacture of sugar,
from the sap of the maple tree, is copied from the
North American Sylva of Michaux.
The work is commonly taken in hand in the month of
February, or in the beginning of March, while the cold
continues intense, and the ground is still covered with
snow. The sap begins to be in motion at this season,
two months before the general revival of vegetation. In
a central situation, lying convenient to the trees, from
which the sap is drawn, a shed is constructed, called, a
sugar-camp, which is destined to shelter the boilers, and
the persons who attend them, from the weather. An
auger, three quarters of an inch in diameter, small troughs
to receive the sap, tubes of elder or sumac, eight or ten
inches long, corresponding in size to the auger, and laid
open for a part of their length, buckets for emptying the
troughs and conveying the sap to the camp, boilers of
€fteen or eighteen gallons capacity, moulds to receive the
sirup when reduced to a proper consistency for being
<"ormed into cakes, and, lastly, axes to cut and split the
fuel, are the principal utensils employed in the operation.
The trees are perforated in an obliquely ascending di-
rection, eighteen or twenty inches from the ground, with
two holes, four or five inches apart. Care should be tak-
en that the augers do not enter more than half an inch
within the wood, as experience has shown the most abun-
dant flow of sap to take place at this depth. It is also
recommended to insert the tubes on the south side of the
tree ; but this useful hint is not always attended to.
The troughs, which contain two or three gallons, are
made in the Northern States, of white pine, of white
or black oak, or of maple ; on the Ohio, the mulberry,
which is very abundant, is preferred. The chestnut,
the black walnut, and the , butternut should be rejected,
as they impart to the liquid the coloring matter and bitter
principle, with which they are impregnated.
A trough. is placed on the ground, at the foot of each
tree, and the sap is, every day, collected and temporarily
II. 20 XII.
338 APPENDIX.
poured into cask J, from which it is drawn out to fill the
boilers. The evaporation is kept up by a brisk fire, and
the scum is carefully taken ojBf during this part of the ])ro-
cess. Fresh sap is added, from time to time, and the
heat is maintained, till the liquid is reduced to a sirup,
after which it is left to cool, and then strained through a
blanket, or other woollen stuff, to separate the remaining
impurities.
Some persons recommend leaving the sirup, twelve
hours, before boiling it for the last time ; others proceed
with it immediately. In either case, the boilers are only
half filled, and by an active, steady heat, the hquor is
rapidly reduced to the proper consistency for being poured
into the moulds. The evaporation is known to have pro-
ceeded far enough, when, upon rubbing a drop of the
sirup between the fingers, it is perceived to be granular.
If it is in danger of boihng over, a bit of lard or of but-
ter is thrown into it, which instantly calms the ebullition.
The molasses being drained off from the moulds, the
sugar is no longer dehquescent, like the raw sugar of the
West Indies. Maple sugar, manufactured in this way, is
lighter colored, in proportion to the care with which it is
made, and the judgement wnh which the evaporation is
conducted. It is superior to the brown sugar of the
Colonies, at least, to such as is generally used in the
United States ; its taste is as pleasant, and it is as good
for culinary purposes. When refined, it equals in beauty
the finest sugar consumed in Europe.
The sap continues to flow for six weeks ; after which,
it becomes less abundant, less rich in saccharine matter,
and sometimes even incapable of crystallization. In this
case, it is consumed in the state of molasses, which is
superior to that of the West India Islands. After three
or four days exposure to the sun, maple sap is converted
into vinegar, by the acetous fermentation.
The amount of sugar manufactured in a year varies,
from different causes. A cold and dry winter renders
the trees more productive than a changeable and humia
season. It is observed, that when a frosty night is follow-
ed by a dry and brilliant day, the sap flows abundantly :
MANUFACTURE OF BEET SUGAR 339
and two or three gallons are sometimes yielded oy a single
tree, in twenty-four hours. Three persons are found
sufficient to tend two hundred and fifty trees, which give
one thousand pounds of sugar, or four pounds from each
tree. But this product is not uniform, for many farmers
on the Ohio do not commonly obtain more than two
pounds from a tree.
Trees, which grow in low and moist places, afford a
greater quantity of sap, than those, which occupy rising
grounds, but it is less rich in the saccharine principle.
That of insulated trees, left standing in the middle of
fields, or by the side of fences, is the best. It is also re-
marked, that in districts which have been cleared of othei
trees, and even of the less vigorous sugar maples, the pro-
duct of the remainder is proportionally more considerable.
VII. — Of the Manufacture of Beet Sugar.
The following account of this manufacture, in France,
is extracted from a work compiled, in 1836, by Mr. Ed-
ward Church.
Cleansing of the Beet Roots.
The object of this operation is, to separate from the
loots the green parts of the neck, w^hich may not have
been removed, the radicles, the defective parts, and the
earth and the gravel which may adhere to these ; when
this is properly done, the washing, should it be required,
(which is not the case in many places,) is easily and
quickly performed. In all cases, the cleansing should be
effectually done, otherwise the gravel and earth (should
there any remain) will injure the rasps. "Women and
children perform this operation in France. For this pur-
pose, each hand is provided with a sharp knife, from two
to three inches broad, and ten long. With this tool,
seated near a pile of beets, the laborer takes the beets one
after another, scrapes them lengthwise, to detach the earth
and stones, takes off the neck all round, and even a thin
shce, when this has not been already done.
When a beet is too large to be applied conveniently to
the rasp, the workmen should cut it in two, or in quarters,
340 APPENDIX.
according to its dimeisions. This must always be done
longitudinally.
The cleaning of the beets should always take place in a
room near the rasps and presses, in order that these dif-
ferent operations may follow conveniently and quickly.
The place should be, w^hen possible, a building sufficient-
ly large to contain beets enough for the consumption of
the works for at least four or five days, and leave room
enough besides for the laborers to do their w^ork easily.
As fast as the roots are cleansed, they should be thrown
into baskets about eighteen inches high, and a foot w-ide,
of a conical shape, with handles. When several of these are
filled they are carried to the rasp ; there they leave the
full baskets and take back the empty ones. Two women,
in France, who understand their business, can clean easily
from three to three and one half tons of roots in twelve
hours' work, and carry them to the rasp. The wages of
these women, in some parts of France, do not exceed
twelve or fifteen cents each, per day ; at this rate, the
cleaning of a ton of beets would not cost over ten cents.
It, of course, reduces the weight of the beet ; the loss is
estimated, usually, at from six to seven per cent.
The operation of washing the roots is, (as we before
said,) by no means generally requisite ; and a careful
cleansing, as described above, is decidedly preferable, and
it is not always, that water in sufficient quantity can be con-
veniently obtained. When a little stream is at hand, and
they can be placed in baskets in the water, and remain till
the earth is washed off by its motion, such a peculiar ad-
vantage should never be neglected ; but this of rare occur-
rence.
This washing is the more difficult, too, as it must be
executed in the winter, and the water frequently may be
frozen. A general opinion once prevailed, that the cleans-
ing with water was indispensable, and that the manufacture
of sugar could not be undertaken without a locality which
supplied an abundance of it ; but this supposed necessity
is groundless, for there are few spots where a sufficiency
of water may not be found for the inconsiderable wants of
a beet sugar manufactory.
MANUFACTURE OF BEET SUGAR. 341
Rasping the Beets.
The first idea of the famous Achard, when in search of
the best mode of extracting the sugar from beets, was to
boil them and reduce them to paste ; but he soon found
insuperable difficulties in the way of this process. The
simple pressure without rasping has been repeatedly tried,
and recently again by an improved press, and the rasp is
as yet the only effectual mode employed, and too much
care cannot be used in having this operation well done, as
on it depends, in a great measure, the more or less sugar
that is obtained. The^e is a great diversity in the con-
struction of this machine, but the cylindrical rasp'of Mo-
lard appears to have the preference. The cylinder is of
cast-iron, into which one hundred and twenty saw plates
are inserted. Asa description of this would probably be
unintelligible without a representation of it by an engrav-
ing, I will not attempt it. A man presses the beets en-
closed in a box against the circumference of the cyhnder,
another w^orkman, on the opposite side of the machine, re-
moves the pulp, and, with the ladle with which he removes
it, fills bags, as we shall more particularly explain hereaf-
ter. From eighty to one hundred pounds of beet are re-
duced to pulp, in one minute.
The rasping requires, as well as every other operation
of this manufacture, great activity ; and, as much as possi-
ble, the rasping more beets than are immediately wanted,
must be avoided, as a prejudicial change takes place in
the pulp, from a quarter to a half hour, at most, after it is
'produced. A blackish color, which gradually increases, is
the indication of this change. It is therefore prudent that
no more should be rasped than can be immediately pressed.
The rasp must be kept perfectly clean by repeated wash-
ings. Once a day, at least, every part of the machine, and
all the tools appertaining to it, should be carefully cleansed,
because every portion of juice, or pulp, which is suffered
to remain on them, would soon serve as a leaven to excite
fermentation.
It is immaterial what power is used to drive the rasps ;
29*
342 APPENDIX.
animal, water, and steam, power, and even wind, is some-
limes used in France.
Extraction of the Beet Juice.
A variety of machines, and of power, has been used,
for the pressing of the pulp, as well as for raspjng the
roots. Of late the Hydraulic press has superseded almost
every other, for this last operation, at least, in large man-
ufactories. The pulp, enclosed in bags, is submitted to
the action of this machine ; the bags are usually made of
Russia duck. The cloth, though required to be strong,
must not be so close that the juice cannot easily pass
through it, or they will otherwi^ burst ; on the other
hand, it must be sufficiently so, to prevent the pulp
passing through the tissue.
This last defect, however, is less to be feared than the
first, so that the caution, most to be attended to, is, to
avoid too close a texture ; and it must be recollected that
it will become-closer when saturated with the juice. The
size of the bags may be varied, but, generally speaking,
half a yard wide and one yard long is a convenient di-
mension ; they should not be more than three fourths filled.
The bags must be kept perfectly clean, and they should
be washed every day in boiling water^ with a small addi-
tion of the-sub-carbonate of soda. Wicker-work frames,
on which the bags are to be piled, must be provided ;
they should be made strong, and proportioned to the size
of the platform of the press, that is, of the same dimen-
sions ; they serve to support the piles of bags in their
vertical position, on the hand-wagon, with which they are
removed from the rasp to the press, and are themselves
kept in place, when on the press, by stanchions, fixed to
the platform of the press at the lower end, the other
sliding through a groove fixed to the frame-work. These
wicker- frames and bags are placed alternately under the
press, usually to the number of thirty of each. As re-
gards these frames, the caution of the cleanliness is re-
newed, and, in a word, must be applied to every branch
of this manufactory.
A Reservoir is next to be provided, to receive the
MANUFACTURE OF BEET SUGAR. 343
juice from the press, to be subsequently conveyed to the
defecating boiler ; it must be supplied with pipes of com-
munication with the press, and a pump to convey the
juice it contains to the defecating boiler ; it should be
placed on a lower level than the press, and receive the
juice by an inclined plane. It must be made substantial-
ly of wood, and lined wnth copper, having a concavity in
the centre, into which the bottom of the pump must be
inserted, so as to empty it completely. The capacity
must, of course, depend on the extent of the manufactory.
Mode of operating with the Press.
When the bags and wicker-frames have been pded as
before described, alternately, to the number of thirty or
more of each, on the platform, and the stanchions placed,
the weight of the pulp alone causes a pretty plentiful flow
of juice ; if the press used is a screw press, a workman
takes hold of the lever, and turns it, then a second man
assists, and then a third. When they have exerted their
united strength on the lever, the job is done, and, after al-
lowing the bags to drain, whilst they are filling others,
the press is unscrewed, the bags removed, the pulp cakes
disposed of, the bags cleansed, and the operation first de-
scribed is continued, till the whole quantity of pulp pre-
pared is disposed of.
Defecation of the Juice.
The juice of the beet, as it comes from the press, car-
ries with it all the soluble parts of the root. It contains,
in this state, not only sugar and icater, but other compo-
nent parts, which cannot be separated by evaporation
alone ; they must be precipitated by chemical agents. Ma-
ny and experfiive experiments were made in search for
these, which I shall not here attempt to explain. The
present process is as follows : Suppose a boiler contain-
ing four hundred gallons of juice ; add,^e/o?'e lighting the
fire, eight pounds sulphuric acid at sixty-six degrees, one
part acid, three parts water, diluted, mix quickly and
thoroughly with the juice, then take nine pounds of quick-
lime, weighed before it is slaked, then slake with warm
344 APPENDIX.
water to the consistency of milk, throw this also into the
juice, and stir the whole completely ; the fire is now to
be kindled under the boiler, and its contents raised to the
temperature of one hundred and ninety degrees of Fah-
renheit ; then animal carbon, that has been employed in
clarification, is added, and well mixed, and a portion of
diluted ox blood stirred in carefully ; the fire is withdrawn,
the juice allowed to settle, and is drawn off clear, through
a cock placed near the bottom of the boiler. It is im-
portant to observe that the juice, when the sulphuric acid
is added, must not be warm. This process has failed in
the hands of some imitators of M. Crespel, from a mis-
take on this point. M. Dubrunfaut acknowledges that he
himself committed it.
Concentration of the Juice.
For this purpose, one or more boilers are necessary,
with which the evaporation is begun and finished ; in these
the juice from the defecating boiler is received clear ;
then a slow fire is kept up m the beginning, and some al-
buginous matter, (white of eggs, or blood,) added, if it
should seem to be required. After this, a man must at-
tend closely to the boiler, and manage the fire. When froth
appears, it will be his duty to throw a small piece of but-
ter, or other grease, (which he should have near him,) into
the vessel, which will immediately cause it to subside ; he
should also have a ladle to stir it when required. When
th() juice has reached the proper point, that is to say,
twenty-six degrees of Baumes's areometer, when boiling,
that is thirty degrees, when cold, it is time to proceed to
the operation of clarifying.
Clarifying.
The object of this is, to separate the sirup concen-
trated to thirty degrees, or near it, from the extraneous
matter which it Rolds in suspension, and moreover to de-
prive it, by clarifying agents, of all coloring matter, and
other foreign substances which ivere in the juice, or have
formed there whilst under the preceding operation, all
which matter is injurious to the sugar. Clarification mav
MANUFACTURE OF BEET SUGAR. 345
be divided into two distinct branches, the one chemical,
having for its object, by clarifying agents, such as animal
carbon, albumine, &c., to purify the sirup ; the other, me-
chanical, having for its object to separite from the same,
the carbon and other sohd bodies agglomerated by the al-
bumine.
The first is managed with a boiler, only because the
action of the chemical agents employed require to be
aided by heat
Of all the means hitherto devised for clarification, none
has been found so simple and so effective as that offered
by the use of animal carbon, and albuginous or caseous
matter.*
We will here suppose that the object in view is to
clarify the portion of sirup, supphed by the defecation of
one hundred gallons of juice, that is, sixteen and a half
gallons of sirup concentrated to twenty-six degrees boil-
ing and thirty degrees cold ; (it follows that for any other
quantity it is only required to follow the same proportion ;)
to do this, we must proceed to weigh eight pounds of ani-
mal carbon, and throw it into the boiler ; the sirup, when
boiling, should be well stirred with the ladle, then with the
skimmer ; the black agglomerated matter which rises to
the surface should be broken up, and mixed again with the
liquid ; when it is apparent that the carbon is sufficiently
separated and mixed with the sirup, it may be left to boil
for a few minutes. The sirup now assumes a turbid and
murky appearance ; whilst this operation is proceeding, s
quart of ox blood, or the white of four eggs, should be
beat up, and diluted with water, or otherwise, two quarts-
of skimmed milk- This mixture must now be thrown into
the boiler, taking care to mix the whole, well together.
The ebullition will, of course, have been stopped by this
addition ; and it is proper, till it begins again to boil, tiiat it
should be constantly stirred, to prevent the precipitation
of the ingredients ; the ebullition must be kept up for a
few minutes, and the sirup is then prepared for filtration.
* The process we are about to describe is varied by different man
ufacturers. By some, the acid is omitted altogether, and other agents
■ubstituted.
vM6 APPENDIX.
Filtration.
This is an exceedingly simple operation ; a flannel cloth
fixed to a frame is all that is required.
Sirup at the density of thirty degrees cold, as it comes
from the filterer, is not sufficiently concentrated to crystal-
lize ; it is therefore necessary to submit it to another boil-
ing, to evaporate the superabundant water it still contains,
and so to produce the required crystallization.
This operation is only a continuation of the concentra-
ting process, and also its completion ; the same boiler,
which is suitable for the first part of this process, is the
one now again required, the fire must be carefully attend-
ed to, the sirup skimmed when required, and, if it rises in
foam, must be stopped, as before, by a piece of grease ;
when the proof shows ninety and one half to ninety-one
of Reaumer, two hundred and thirty-six degrees Fahren-
heit, which point it may reach, if the sirup is very good,
it is time to stop and empty the boiler. It would be more
prudent to do so at eighty-nine and one half; the sugar
would purify more easily, and, as the molasses must neces-
sarily be reboiled, this supports the operation, all the bet-
ter, for being a little richer in sugar.
The sixteen and one half gallons, with which we began
our experiment, will new be reduced to ten and one half
gallons. In this state it may be turned into a vessel, to
cool gradually, where it may stay for ten or twelve hours,
when it will fall to the temperature of one hundred and
seventy degrees, or one hundred and eighty degrees, Fah-
renheit, and then may be put into the pots for crystalliza-
tion. These usually contain six to eight gallons. In turning
It 'nto these, masses of the crystals will be found, already,
at the bottom and sides of the vessel. If the sirup is good,
some attention is necessary in this operation, that the sirup
should not be left to get too cold, before it is turned into
die pots ; as this would, in some degree, impede the crys-
tallization. These should be kept in a close room, and at a
steady temperature. The pots are of a conical form, with
a hole in the bottom, which is stopped with a cork or clay.
Thirty-six or forty hours after the sirup has remained in
MANUFACTURE OF BEET SUGAR. 347
them, and when the temperature is reduced to seventy-
seven degrees, Fahrenheit, or thereabout, the cork is re-
moved, and the point of the cone placed over a vessel into
which the molasses (which begins immediately to run) is
received. In about fifteen days, in a temperature of from
sixty to sixty-five degrees, Fahrenheit, they have furnished
above two thirds of their molasses. In this degree of heat
L e ichole of the molasses will not separate from the sugar ;
the pots are therefore removed to another room, where the
temperature is kept at from one hundred and twenty to one
hundred and forty degrees, Fahrenheit. There they are
again placed over the recipients ; but, before doing. this, a
rod is. thrust through the hole in the point of the cone, to
break the incrustation of sugar within, and facilitate the
draining of the molasses. After remaining here fifteen
days, the sugar must be completely freed from the molas-
ses, and must now be taken out. For this purpose, the
cone is placed on its base, shook against the platform on
which it stands, and, in an hour or so, the sugar is de-
tached in the form of the cone ; the point of this is im-
pregnated with molasses, and is to be removed. It makes
an inferior sort of brown sugar. The rest of the product
will be generally fine, light colored sugar, which is found
to produce a larger proportion of refined sugar to the
weight, than any made from the cane, and is, therefore,
much preferred by refiners. The sugar made at the be-
ginning of the season is easier made, and better than that
made later.
The molasses collected in the process of crystallization,
is reboiled, and subjected to the same process as the sir-
up, and a certam portion of sugar is the result ; the re-
siduum is used for many purposes, and is especially use-
ful for cattle.
For further particulars, see the w'ork cited ; also, a man-
ual translated from portions of the treatise of M. M.
Blachette, Zoega, and J. De Fontenelle, and published
by Marsh, Capen, Lyon, and Webb, and a more recent
work, on the same subject, by David Lee Child.
348 APPENDIX.
VIII. — Voltaic Electrical Engraving.
The following account of the process of engraving in
relief, upon copper-plates, by means of voltaic electricity,
is from the London Atheneum, for October 27, 1839.
A previous number of this paper contained a letter from
M. Jacobi, detailing his experiments on the subject ; and
it appears that Mr. Thomas Spencer, of Liverpool, had
also devoted much attention to the subject, and had noi
only succeeded in doing all that M. Jacobi had done, but
had surmounted difficulties which M. Jacobi could not.
Mr. Spencer proposes, by means of voltaic electricitv,
" to engrave in rehef upon a plate of copper ; deposit a
voltaic copper-plate, having the lines in relief; obtain a
facsimile of a medal, reverse or obverse, or of a bronze'
cast ; to obtain voltaic impression from plaster, or clay ,
and to multiply the number of already-engraved copper-
plates." The results which he has already obtained are
said to be very beautiful.
Take a plate of copper, such as is used by an engrav-
er ; solder a piece of copper wire to the back part of it,
and then give it a coat of wax; (this is best done by heat-
ing the plate, as well as the wax ;) then write or draw the
design on the wax, with a black lead pencil, or a point.
The wax must now be cut through with a graver, or steel
point, taking special care that the copper is thoroughly
exposed, in every line. The shape of the tool or graver
employed must be such, that the lines made are not V-
shape, but, as nearly as possible, with parallel sides. The
plate should next be immersed in dilute nitric acid ; say
three parts water to one of acid. It will at once be seen
whether it is strong enough, by the green color of the so-
lution, and the bubbles of nitrous gas evolved from the
copper. Let the plate remain in it long enough for the
exposed lines to get slightly corroded, so that any minute
portions of wax, which might remain, may be removed.
The plate, thus prepared, is placed in a trough, separat-
ed into two divisions by a porous partition of plaster of
Paris, or earthenware ; the one division being filled with
a saturated solution of sulphate of copper, and the othei
VOLTAIC ELECTRICAL ENGRAVING. 349
with a saline, or acid, solution. The plate to be engrav-
ed is placed in the division containing the solution of the
sulphate of copper, and a plate of zinc, of equal size, is
placed in the other division. A metallic connection is
.hen made between the copper and zinc plates, by means
of the copper wire soldered to the former ; and the vol-
taic circle is thus completed. The apparatus is then left
for some days. As the zinc dissolves, metalhc copper
is precipitate J, from the solution of the sulphate on the
copper-plate, wherever the wax has been removed by
the engraving tool. After the vohaic copper has l^en
deposited in the lines engraved in the wax, the surface
of it will be found to be more or less rough, according to
the quickness of the action. To remedy this, rub the
surface with a piece of smooth flag, or pumice-stone, with
water. Then heat the plate, and wash off the wax
ground, with spirits of turpentine and a brush. The
plate is now ready to be printed from, at an ordinary
press.
In this process, care must be taken that the surface of
the copper in the lines be perfectly clean, as otherwise,
the deposited copper will not adhere with any force, but
is easily detached w^hen the wax is removed. It is in
order to insure this perfect cleanness of the copper, that
it is immersed in dilute nitric acid. Another cause of
imperfect adhesion of the deposited copper, which Mr.
Spencer has pointed out, is the presence of a minute
portion of some other metal, such as lead, which, by be-
ing precipitated before the copper, forms a thin film,
which prevents the adhesion of the subsequently deposit-
ed copper. This circumstance may, however, be turn-
ed to advantage, in some of the other applications of
Mr. Spencer's process, where it is desirable to prevent
the adhesion of the deposited copper.
In copying a coin, or medal, Mr. Spencer describes
two methods. The one is by depositing voltaic copper on
the surface of the medal, and thus forming a mould, from
which, facsimiles of the original medal may readily be ob-
tained, by precipitating copper into it. The other is
even more pxpeditious. Two pieces of clean milled
II. 30 XII.
350 APPENDIX.
sheet lead are taken, and the medal being placed between
them, the whole is subjected to pressure in a screw-press,
and a complete mould, of both sides, is thus formed in .
the lead, showing the most delicate lines, (in reverse.)
Twenty, or even a hundred, of these, may be so formed
on a sheet of lead, and the copper deposited by the vol-
taic process, with the greatest facility. Those portions
of the surface of the lead, which are between the moulds,
may be varnished, to prevent the deposition of the lead,
or, a whole sheet of voltaic copper having been deposi-
teci^ the medals may afterwards be cut out. When cop-
per is to be deposited on a copper mould, or medal, care
must be taken to prevent the metal deposited adhering.
This Mr. Spencer effects by heating the medal, and
rubbing a small portion of wax over it. This wax is then
wiped off, a sufficient portion always remaining to pre-
vent adhesion.
Enough has been said, to enable any one to repeat,
and follow up, Mr. Spencer's interesting experiments.
The variations, modifications, and adaptations, of them,
are endless ; and many new ones will naturally suggest
themselves to every scientific reader.
IX. — Photogenic Drawing.
Some account of Photography, or Photogenic drawing
has been introduced in the previous pages of this work
The following article, containing a description of the pro-
cess, is from a work on this subject, published by M. Da-
guerre, and translated by Mr. Memos, in 1839.
The designs are executed upon thin plates of silver,
plated on copper. Although the copper serves princi-
pally to support the silver foil, the combination of the two
metals tends to the perfection of the effect. The silver
must be the purest that can be procured. As to the cop-
per, its thickness ought to be sufficient to maintain the
perfect smoothness and flatness of the plate, so that the
images may not be distorted by the warping of the tablet;
but unnecessary thickness, beyond this, is to be avoided,
on account of the weight. The thickness of the two
metals united ought not to exceed that of a stout card
PHOTOGENIC DRAWING. 351
The process is divided into five operations.
1. The first consists in polishing and cleaning the
plate, in order to prepare it for receiving the sensitive
coating, upon which the light traces the design.
2. The second is to apply this coating.
3. The third is the placing the prepared plate, proper-
ly, in the camera obscura, to the action of hght, for the
purpose of receiving the image of Nature.
4. The fourth brings out this image, which, at first, is
not visible, on the plate being withdrawn from the camera
obscura.
5. The fifth, and last, operation has, for its object, to
remove the sensitive coating on w^hich the design is first
impressed, because this coating would continue to be af-
fected by the rays of light, a property w^hich would ne-
cessarily and quickly destroy the picture.
First Operation. — Preparing the Plate.
The requisites, for this operation, are,
A small phial containing olive oil.
Some very finely-carded cotton.
A small quantity of very fine pumice powder, ground
with the utmost care, tied up in a bag of muslin, suffi-
ciently thin to allow the powder to pass through, when the
bag is shaken.
A phial of nitric acid, diluted with water, in the pro-
portion of one pint of acid, to sixteen pints of distilled
water. These proportions express volume, not weight.
A frame of iron wire, upon which to place the plate,
in order that it may be heated by means of a spirit-lamp.
Lastly, a small spirit-lamp.
As already stated, these photographic delineations are
executed upon silver, plated on copper. The size of the
plate will depend, of course, on the dimensions of the
camera. We must begin, by polishing it carefully. To
accomplish this, the surface of the silver is powdered all
over with the pumice, by shaking the bag, without touch-
*ng the plate.
Next, with some cotton dipped in a little olive oil, the
operator rubs die plate gently, rounding his strokes. Dur-
352 APPENDIX.
«
ing this operation, the plate must be laid flat upon several
folds of paper, care being taken to renew these, from time
to time, that the tablet be not twisted from any inequality
in the support.
The pumice must be renewed, and the cotton changed^
several times. The mortar, employed for preparing the
pumice, must be of porphyry. The powder is afterwards
finished, by grinding upon polished glass with a glass
muller, and very pure water. And lastly, it must be
perfectly dried. It will be readily apprehended, of what
importance it is to attend to these directions, since upon
the high polish of the silver, depends, in a great measure,
the beauty of the future design. When the plate is well
polished, it must next be cleaned, by powdering it all
over, once more, with pumice, and rubbing with dry cot-
ton, always rounding and crossing the strokes, for it is
impossible to obtain a true surface by any other motion
of the hand. A little pledget of cotton is now rolled up,
and moistened with the diluted acid already mentioned,
by applying the cotton to the mouth of the phial, and in-
verting it, pressing gently, so that the centre only of the
cotton may be wetted, and but slightly, care being taken,
not to allow any acid to touch the fingers. The surface
of the plate is now rubbed equally, all over, with the
acid, applied by the pledget of cotton. Change the cot-
ton, and keep rubbing, rounding as before, that the acid
may be equally spread, yet in so small a quantity, as just
to skim the surface, so to speak. If, as frequently hap-
pens, the acid run into small drops, from the high polish,
change the cotton repeatedly, and break down the glob-
ules as quickly as possible, but always by gently rubbing,
for if allowed to rest, or to run upon the plate, they will
leave stains. It will be seen when the acid has been
properly diffused, from the appearance of a thin veil,
spread regularly over the whole surface of the plate. Once
more powder over pumice, and clean it with fresh cotton,
rubbing as before, but very slightly.
The plate is now to be subjected to a strong heat. It
is placed upon the wire frame, the silver upwards. The
spirit-lamp is applied below the hand, moving it round.
PHOTOGENIC DRAWING. 353
the flame touching and playing upon the copper. This
operation being continued at least five minutes, a white
strong coating is formed all over the surface of the silver,
if the lamp has been made to traverse with proper regu-
larity. The lamp is now withdrawn. A fire of charcoal
may be used instead of the lamp, and is, perhaps, prefera-
ble, the operation being sooner completed. In this latter
case, the wire frame is unnecessary, because the plate
may be held by one corner with pincers, and so held over
the fire, moving it at the same time, till all is equally heat-
ed, and the veil appear, as before described.
The plate is now to be cooled, suddenly^ by placing it
on a cold substance, such as a mass of metal, or stone, or,
best of all, a marble table. When perfectly cold, it is to
be again polished, an operation speedily performed, since
the gummy appearance merely has to be removed, which
is done by the dry pumice and cotton, repeated several
times, changing the cotton frequently. The polishing
being thus completed, the operation of the acid is to be
repeated three diiferent times, dry pumice being powder-
ed over the plate, each time, and polished off very gen-
tly with the cotton, which must be very clean, care being
taken not to breathe upon the plate, or to touch it with the
fingers, or even with the cotton upon which the fingers
have rested ; for the slightest stain upon the surface will
be a defect in the drawing.
When the plate is not intended for immediate use, the
last operation of the acid is not performed. This allows
any number of plates to be kept prepared, up to the last
slight operation ; and they may be purchased in this state,
if required. It is, however, indispensable, that a last
operation by acid, as described, be performed on every
plate, immediately before it be placed in the camera.
Lastly, every particle of dust is removed, by gently
cleaning the whole edges, and back, also, with cotton.
Second Operation. — Coating the Plate.
For this operation, we require,
A box.
A small board.
30*
354 APPENDIX.
Four small metallic bands, the same substance as the
})lates.
A small handle, and a box of small tacks.
A phial of iodine.
The plate is first to be fixed on the board, by means
of the metallic bands, with their small catches and tacks.
The iodine is now put into a little dish at the bottom of
the box. It is necessary to divide the iodine into pieces,
in order to render the exhalation the more extensively
and more equally diffused ; otherwise, it would form cir-
cles in the centre of the plate, which would destroy this
essential requisite. The board is now fitted into its po-
sition, the plate face downwards, the whole being support-
ed by small brackets projecting from the four corners of
the box, the lid of which is then closed. In this posi-
tion, the apparatus remains till the vaporization of the
iodine, which is condensed upon the plate, has covered
its surface with a fine coating of a yellow gold color. If
this operation be protracted, the gold color passes into
violet, which must be avoided ; because in this state the
coating is not so sensitive to the impressions of hght.
On the contrary, if the coating be too pale, the image of
\ature in the camera will be too faint to produce a good
picture. A decided gold color, — nothing more, nothing
less, — is the only assurance that the ground of the future
picture is duly prepared. The time for this cannot be
determined, because it depends on several circumstances.
Of these, the two principal are the temperature of the
apartment, and the state of the apparatus. The opera-
tion should be left entirely to spontaneous evaporation of
the iodine ; or, at all events, no other heat should be used,
than what can be applied through the temperature of the
room, in which the operation takes place. It is also very
important, that the temperature of the inside of the box
be equal to that of the air outside ; for, otherwise, a depo-
sition of moisture takes place upon the plate, a circum-
stance most injurious to the final result. Secondly, as
respects the state of the apparatus ; the oftener it has
been used, the less time is required, because, in this case,
the interior of the box being penetrated with the vapors
PHOTOGENIC DRAWING. 355
of iodine, these arise from all sides, condensing thus more
equally and more rapidly upon the surface of the plate ; a
very important advantage. Hence, it is of consequence
to leave always a small quantity of iodine in the cup, and
to protect this latter from damp. Hence, likewise, it is
obvious, that an apparatus of this kind, which has been
some time in use, is preferable to a new box ; for, in
the former, the operation is always more expeditiously
performed.
Since, from these causes, the time cannot be fixed, a
priori, and may vary from five minutes to half an hour,
rarely more, unless the weather be too cold, means must
be adopted for examining the plate, from time to time.
In these examinations, it is important not to allow the
fight to fall directly upon the plate. Also, if it appear
that the color is deeper on one side of the plate than the
other, to equalize the coating, the board must be re-
placed, not exactly in its former position, but turned one
quarter round, at each inspection. In order to accom-
plish these repeated examinations, without injuring the
sensibility of the ground, or coating, the process must be
conducted in a darkened apartment, into which the light
is admitted sideways, never from the roof ; the door left
a little ajar answers best. When the operator would
inspect the plate, he raises the lid of the box, and, lifting
the board with both hands, turns up the plate quickly,
and very fittle fight suffices to show him the true color
of the coating. If too pale, the plate must be instantly
replaced, till it attain the proper gold tone ; but if this
tint be passed, the coating is useless, and the operations
must be repeated from the commencement of the first.
From description, this operation may, perhaps, seem
difficult ; but with a little ])ractice, one comes to know,
pretty nearly, the precise interval necessary to produce
the true tone of color, and also to inspect the plate with
great rapidity, so as not to allow time for the light to act.
When the coating has reached the proper tone of yel-
low, the plate, with the board to w^hich it is fixed, is slip-
ped into the frame, and thus adjusted, at once, in the ca-
mera. In this transference, care must be taken to protect
356 APPENDIX.
the plate from the light. A taper should be used ; and
even with this precaution, the operation ought to be per-
formed as quickly as possible, for a taper will leave traces
of its action, if continued for any length of time.
We pass now to the third operation, that of the ca
mera. If possible, the one should immediately succeed
the other ; the longest interval between the second and
third ought not to exceed an hour. Beyond this space,
the action of the iodine and silver no longer possesses the
requisite photogenic properties.
Observanda. — Before making use of the box, the oper-
ator should clean it thoroughly, turning it bottom upwards,
in order to empty it of all the particles of iodine which
may have escaped from the cup, avoiding, at the same
time, touching the iodine with the fingers. During the
operation of coating, the cup ought to be covered with a
piece of gauze stretched on a ring. The gauze regulates
the evaporation of the iodine, and also prevents the com-
pression of the air, on the lid being shut, from scattering
the particles of iodine, some of which, reaching the plate,
would leave large stains on the coating. For the same
reason, the top should always be let down with the great-
est gentleness, not to raise the dust in the inside, the par-
ticles of which, being charged with the vapor of the io
dine, would certainly reach and damage the plate.
Third Operation. — The Camera.
The apparatus, required in this operation, is limited tt
the camera obscura.
This third operation is that, in which, by means ol
light, acting through the camera. Nature impresses an
image of herself on the photographic plate, enlightened
by the sun, for then the operation is more speedy. It
is easy to conceive that this operation, being accom-
plished only through the agency of light, will be the more
rapid in proportion as the objects, whose photographic
images are to be delineated, stand exposed to a strong
illumination, or in their own nature present bright lines,
and surfaces.
After having placed the camera in front of the land
PHOTOGENIC DRAWING. 357
scape, or facing any other object of which it may be desi-
rable to obtain a representation, the first essential is a per-
fect adjustment of the focus, that is to say, making your
arrangements, so as to obtain the oudines of the subject
with great neatness. This is accomplished, by advancing
or withdrawing the frame of the obscured glass, which re-
ceives the images of natural objects. The adjustment
being made with' satisfactory precision, the movable part
of the camera is fixed by the proper means, and the ob-
scured glass being withdrawn, its place is supplied by the
apparatus, with the plate attached, as already described,
and the whole secured by small brass screws. The light
is, of course, all this time excluded by the inner doors.
These are now opened, by means of two semicircles, and
the plate is disposed, ready to receive its proper impres-
sions. It remains only to open the aperture of the ca-
mera, and to consult a watch.
This latter is a task of some nicety, inasmuch as noth-
ing is visible, and it is quite impossible to determine
the time necessary for producing a design, this depending
entirely on the intensity of the light on the objects, the
imagery of which is to be reproduced. At Paris, for ex-
ample, this varies from three to thirty minutes.
It is likewise to be remarked, that the seasons, as well
as the hour of the day, exert considerable influence on
the celerity of the operation. The most favorable lime
is from seven to three o'clock ; and a drawing which, in
the months of June and July, at Paris, may be taken in
three or four minutes, will require five or six, in May or
August ; seven or eight, in April and September ; and so
on, in proportion to the progress of the season. These
are only general data for very bright, or strongly illumin-
ated, objects ; for it often happens, that twenty minutes
are necessary, in the most favorable months, when the
objects are entirely in shadow.
After what has just been said, it will readily occur to
the reader, that it is impossible to specify, with precision,
the exact length of time necessary to obtain photographic
designs. Practice is the only sure guide ; and, with this
advantage, one soon comes to appreciate the required
358 APPENDIX.
time, very correctly. The latitude is, of course, a fixed
element in this calculation. In the south of France, for
example, and generally in all those countries, in which
light has great intensity, as Spain, Italy, &c., we can
easily understand that these designs must be obtained with
greater, promptitude, than in more northern regions. It
is, however, very important, not to exceed the time nec-
essary, in different circumstances, for producing a design ;
because, in that case, the lights in the drawing will not be
clear, but will be blackened by a too-prolonged solariza-
tion. If, on the contrary, the time has been too short, the
sketch will be very vague, and without the proper details.
Supposing that he has failed in a first trial, by with-
drawing the tablet too soon, or by leaving it too long ex-
posed, the operator, in either case, should commence
with another plate immediately ; the second trial, being
corrected by the first, almost insures success. It is even
useful, in order to acquire experience, to make some es-
says of this kind.
In this stage of the process, it is the same as for the
coating ; we must hasten to the next operation. When
the plate is withdrawn from the camera, it should imme-
diately be subjected to the subsequent process ; there
ought, at most, not to be a longer interval than an hour,
between the third and fourth operations ; but one is al-
ways surest of disengaging the images, when no space
has been allowed to intervene.
Fourth Operation. — Mercurialj or Disengaging, Process.
Here are required, a phial of mercury, containing at
least three ounces.
A lamp, with spirit of wine.
An iron vessel, prepared with apparatus for receiving
he plate, and submitting it to the vapor of mercury.
A glass funnel with a long neck.
By means of the funnel, the mercury is poured into
the cup, at the bottom of the larger vessel. The quan-
tity must be sufficient to cover the bulb of a thermome-
ter. Afterwards, and throughout the remaining opera-
nons, no light, save a taper, can be used.
PHOTOGENIC DRAWING. iibi
The board, with the plate affixed, is now to be with-
drawn from the frame already described, as adapted to
the camera. The board and plate are placed within the
ledges of the black iron vessel, at an angle of forty-fire
degrees, the tablet with sketch downwards, so that it can
be seen through the glass. The top is then gently put
down, so as not to raise up particles of the mercury.
When all things are thus disposed, the spirit lamp is
lighted, and placed under the cup containing mercury.
The operation of the lamp is allowed to continue till the
thermometer, the bulb of which is covered by the mer-
cury, indicates a temperature of sixty degrees centigrade,
[140°, Fahrenheit.] The lamp is then immediately with-
drawn. If the thermometer has risen rapidly, it will con-
tinue to rise without the aid of the lamp ; but this elevation
ought not to exceed seventy-five degrees centigrade, [167°
Fahrenheit.]
The impress of the image of Nature existy upon the
plate, but it is invisible. It is not till after the lapse cf
several minutes, that the faint tracery of objects begins to
appear, of which the operator assures himself, by looking
through the glass, by the light of a taper, using it cau-
tiously, that its rays may not fall upon, and injure, the nas-
cent images of the sketch. The operation is continued
till the thermometer sink to forty-five degrees centigrade,
[113°, Fahrenheit;] the plate is then withdrawn, and this
operation completed.
When the objects have been strongly illuminated, or
when the action in the camera has been continued rather
too long, it happens that this fourth operation is completed
before the thermometer has fallen even to fifty-five degrees
centigrade. One may always know this, however, by ob-
serving the sketch through the glass.
It; is necessary, after each operation, to clean the inside
of the apparatus carefully, to remove the slight coating of
mercury adhering to it. When the apparatus has to be
packed, for the purpose of removal, the mercury is with-
drawn by a small cock, inclining the vessel to that side.
One may now examine the sketch, by a feeble light, in
order to be certain that the processes hitherto have sue-
360 APPENDIX.
ceeded. The plate is now detached from the board, and
the little bands of metal, which held it there, are carefully
cleaned with pumice and water, after each experiment ;
a precaution rendered necessary from the coating both of
iodine and mercury, which they have acquired. The plate
is now deposited in the grooved box, until it undergoes the
fifth and last operation. This may be deferred, if not con-
venient ; for the sketch may now be kept for months, in
its present state, without alteration, provided it be not too
frequently inspected by the full daylight.
Fifth Operation. — Fixing the Impression.
The object of this final process, is to remove from the
tablet the coating of iodine, which, continuing to decom-
pose by light, would otherwise speedily destroy the de-
sign, when too long exposed. For this operation, the re-
quisites are,
A saturated solution of common salt, or a weak solu-
tion of hyposulphite of pure soda.
An apparatus of japanned white iron, for washing the
designs.
Two square troughs, of sheet copper.
A vessel for distilled w^ater.
In order to remove the coating of iodine, common salt
is put into a bottle, with a wide mouth, which is filled
one fourth with salt and three fourths with pure water.
To dissolve the salt, shake the bottle, and, when the
whole forms a saturated solution, filter through paper.
This solution is prepared in large quantities, beforehand,
and kept in corked bottles. «
Into one of the square troughs, pour the solution, filling
it to the height of an inch ; into the other, pour, in like
manner, your water. The solution of salt may be re-
placed by one of hyposulphite of soda, which is even
preferable, because it removes the iodine entirely, which
the saline solution does not always accomplish, especially
when the sketches have been laid aside for some time, be-
tween the fourth and fifth operations. It does not require
to be warmed, and a less quantity is required.
First, the plate is placed in common water, poured into
PHOTOGENIC DRAWING. 361
a trough, plunging and withdrawing it immediately, the
surface merely requiring to be moistened ; then plunge it
into the saline solution, which latter would act upon the
drawing, if not previously hardened by the washing in
pure water. To assist the effect of the sahne solutions,
the plate is moved about in them, by means of a little hoop
of coppei wire. When the yellow color has quite disap-
peared, the plate is lifted up with both hands, care being
taken not to touch the drawing, and plunged again into
the first trough of pure water.
Next, the apparatus and the bottle having been previ-
ously prepared, made very clean, and the bottle filled with
' distilled water, the plate is withdrawn from the trough, and
being instantly placed upon the inclined plane, distilled
water, hot, but not boiling, is made to flow in a stream
over its whole surface, carrying away every remaining
portion of the saline wash.
If hyposulphite has been used, the distilled water need
not be so hot, as when common salt has been em-
ployed.
Not less than a quart of distilled water is required,
when the design is, in its dimensions, eight and a half by
six and a half inches. The drops of water, remaining on
the plate, must be removed by forcibly blowing upon it,
for otherwise, in drying, they would leave stains on the
drawing. Hence, also, will appear the necessity of using
very pure water ; for if, in this last washing, the liquid con-
tain any admixture of foreign substances, they will be de-
posited on the plate, leaving behind numerous and per-
maq^nt stains. To be assured of the purity of the wa-
ter, let a drop fall upon a piece of polished metal ;
evaporate by heat, and if no stain be left, the water is
pure. Distilled water is always sufficiently pure, without
this trial.
After this washing, the drawing is finished ; it remains
only to preserve it from the dust, and from the vapors
that might tarnish the silver. The mercury, by the ac-
tion of which the images are rendered visible, is par-
tially decomposed ; it resists washing, by adhesion to tho
silver, but cannot endure the slightest rubbing.
II. 31 • XII.
362 APPENDIX.
To preserve these sketches, then, place them in squaies
of strong pasteboard, with a glass over them, and frame
the whole in wood. They are thenceforth unalterable,
even by the sun's light.
In travelling, the collector may preserve his sketches
in a box ; and, for greater security, may close the joints
of tlie lid with a collar of paper.
It is necessary to state, that the same plate may be em-
ployed for several successive trials, provided the silver be
not polished through to the copper. But it is very im-
portant, after each trial, to remove the mercury immedi-
ately, by using the pumice powder with oil, and changing
the cotton frequently during the operation. If this be
neglected, the mercury finally adheres to the silver ; and
fine drawings cannot be obtained, if this amalgam be pres-
ent. They always, in this case, want firmness, neatness,
and vigor of outline, and general effect.
\
A number of experiments, with prepared paper, have
been made by different individuals, with various degrees
of success, in Great Britain. From among the notices
■)f these experiments, as they have appeared in different
ournals, the following selections have been made.
In the spring of 1834, Mr. Talbot began a series of
experiments, with the hope of turning to useful account
the singular susceptibility evinced by the nitrate of silver,
when exposed to the rays of a powerful light. He says,
" In the course of my experiments directed to that end,
I have been astonished at the variety of effects, whk^ I
have found produced, by a very limited number of differ-
ent processes, when combined in various ways ; and also,
at the length of time, which sometimes elapses, before
the full effect of these manifests itself with certainty.
For I have found, that images formed in this manner,
which have appeared in good preservation, at the end of
twelve months from their formation, have nevertheless
somewhat altered, during the second year." He was in-
duced, from this circumstance, to watch more closely the
progress of this change, fearing that, in process of time.
PHOTOGENIC DRAWING. 363
all his pictures might be found to deteriorate. This, how
ever, was not the case, and several have withstood the
action of the Hght, for more than five years.
The images, obtained by this process, are themselves
white, but the ground is differently and agreeably color-
ed ; and, by slightly varying the proportions, and some tri-
fling details of manipulation, any of the following colors
were readily obtained ; light blue, yellow, pink, brown,
black, and a dark green, nearly approaching to black.
The first objects, to which this process was applied,
were leaves and flowers, which it rendered with extraor-
dinary fidelity, representing even the veins and minute
hairs with which they were covered, and which were fre-
quently imperceptible, without the aid of a microscope.
Mr. Talbot goes on to mention, that the following con-
siderations led him to conceive the possibility of discov-
ering a preservative process. Nitrate of silver, which
has become darkened by exposure to the light, is no lon-
ger the same chemical substance as before ; therefore, if
chemical re-agents be applied to a picture, obtained in the
manner already mentioned, the darkened parts will be
acted upon in a different manner from those which re-
tain their original color, and, after such action, they will
probably be no longer affected by the rays of the sun,
or, at all events, will have no tendency to assimilate b}
such exposure ; and, if they remain dissimilar, the pic-
ture will continue distinct, and the great difficulty be over
come.
The first trials of the inventor, to destroy the suscepti-
bility of the metallic oxide, were entirely abortive ; but
he has at length succeeded, to an extent equal to his most
sanguine expectations. The paper, employed by Mr.
Talbot, is superfine writing-paper ; this is dipped into a
weak solution of common salt, and dried with a towel,
till the salt is evenly distributed over the surface ; a solu-
tion of nitrate of silver is then laid over one side of the
paper, and the whole is dried by the heat of the fire.
It is, however, necessary to ascertain, by experiment,
the exact degree of strength requisite in both the ingredi-
ents ; for, if the salt predominates, the sensibility of the
364 APPENDIX.
paper gradually diminishes, in proportion to this excess,
till the effect almost entirely disappears.
In endeavoring to remedy this evil, Mr. Talbot discov-
ered, that a renewed application of the nitrate not only
obviated the difficulty, but rendered the preparation more
sensitive than ever ; and, by a repetition of the same pro-
cess, the mutability of the paper will increase to such a
degree, as to darken of itself, without exposure to the
light. This shows, that the attempt has been carried too
far, and the object of the experimentalist must be to ap-
proach, without attaining this condition. Having prepar-
ed the paper, and taken the sketch, the next object is, to
render it permanent, by destroying the susceptibility of
the ingredients for this purpose. Mr. Talbot tried am-
monia, and several other re-agents, with little success, till
the iodine of potassium, greatly diluted, gave the desired
result : this hquid, when applied to the drawing, produ-
ced an iodine of silver, a substance insensible to the ac-
tion of light. This is the only method of preserving the
picture in its original tints ; but it requires considerable
'licety, and an easier mode is sufficient for ordinary pur-
poses. It consists in immersing the picture in a strong
solution of salt, wiping ofi' the superfluous moisture, and
drj^ing it by the heat of the fire ; on exposure to the sun,
the white parts become of a pale lilac, which is per-
manent and immovable. Numerous experiments have
shown the inventor, that the depth of these tints depends
on the strength of the solution of sah. He also mentions,
that those prepared by iodine become a bright yellow, un-
der the influence of heat, and regain their original color ^on
cooling. Without the application of one of these preserv-
atives, the image will disappear, by the action of the sun ;
but, if enclosed in a portfoho, will be in no danger of altera-
tion : this, Mr. Talbot remarks, will render it extremely
convenient to the traveller, who may take a copy of any
object he desires, and apply the preservative at his leisure.
In this respect, Mr. Talbot's system is superior to that
of M. Daguerre, since it would be scarcely possible for a
traveller to burden himself with a number of metallic plates,
which, in the latter process, are indispensable.
PHOTOGENIC DRAWING. 365
An advantage of equal importance exists in the rapid-
ity with which Mr. Talbot's pictures are executed ; for
which half a second is considered sufficient ; a circum-
stance that gives him a better chance of success in delin-
eating animals, or fohage. — Foreign Quarterly Review.
J^otice of a cheap and simple method of preparing pa-
per for Photograpic Drawings in which the use of any
salt of silver is dispensed with : by Mungo Ponton,
Esq., F. R. S. E., Foreign Secretary Society of Arts
for Scotland. Communicated by the Society of Arts.*
While attempting to prepare paper with the chromate
of silver, for which purpose I used first the chromate of
potash, and then the bichromate of that alkah, I discov-
ered, that, when paper was immersed in the bichromate
of potash alone, it was powerfully and rapidly acted on
b'y the sun's rays. It accordingly occurred to me, to try
paper so prepared, to obtain drawings, though I did not
at first see how they were to be fixed. The result ex-
ceeded my expectations. When an object is laid in the
usual way on this paper, the portion exposed to the light
speedily becomes tawny, passing more or less into a deep
orange, according to the strength of the solution, and the
intensity of the light. The portion covered by the ob-
ject retains the original bright yellow tint, which it had
before exposure, and the object is thus represented yellow
upon an orange ground, there being several gradations of
shade, or tint, according to the greater or less degree of
traasparency in the difierent parts of the object.
In this state, of course, the drawing, though very beau-
tiful, is evanescent. To fix it, all that is required is
careful immersion in water, when it will be found that
those portions of the salt, which have not been acted on
by the light, are readily dissolved out, while those which
have been exposed to the light are completely fixed in
the paper. By this second process, the object is obtained
white, upon an orange ground, and quite permanent. If
exposed, for many hours together, to strong sunshine, the
* Read before the Society of Arts for Scotland, 29th May, 1839.
31*
366 . APPENDIX.
color of the ground is apt to lose in depth, but not moie
so than most other coloring matters.
The action of light, on the bichromate of potash, dif-
fers from that upon the salts of silver. Those of the lat-
ter, which are blackened by light, are of themselves in-
soluble in water ; and it is difficult to impregnate paper
with them, in an equable manner. The blackening seems
to be caused by the formation of oxide of silver. In the
case of the bichromate of potash, again, that salt is ex-
ceedingly soluble, and paper can be easily saturated with
it. The agency of light not only changes its color, but
deprives it of solubility, thus rendering it fixed in the pa-
per. This action appears to me to consist in the disen-
gagement of free chromic acid, which is of a deep red
color, and which seems to combine with the paper. This
is rendered more probable, from the circumstance, that
the neutral chromate exhibits no similar change.
The active power of the light, in this instance, resides
principally in the violet rays, as is the case with the black-
ening of the salts of silver. To demonstrate this, three
similar flat bottles w^re filled, one with ammoniuret of
copper, which transmits the violet rays, one with bichro-
mate of potassa, transmitting the yellow rays, the third,
with tincture of iodine, transmitting the red rays. The
paper was readily acted on through the first, but scarcely,
if at all, through the seconc and third ; although much
more light passed through the bottle filled with bichromate
of potassa, than through the one filled with ammoniuret
of copper.
The best mode of preparing paper with bichromate of
potash is, to use a saturated solution of that salt ; soak
the paper well in it, and then dry it rapidly, at a brisk
fire, excluding it from daylight. Paper, thus prepared,
acquires a deep orange tint, on exposure to the sun. If
the solution be less strong, or the drying less rapid, the
color will not be so deep.
A pleasing variety may be made, by using sulphate of
indigo along with the bichromate of potash, the color of
the object, and of the paper, being then of different shades
PHOTOGENIC DRAWING. 367
of green. In this way, also, the object may bq repre-
sented of a darker shade than the ground.
Paper, prepared with bichromate of potash, is equall}/
sensitive with most of the papers, prepared with salts of
silver, though inferior to some of them. It is not suffi
ciently sensitive for the camera obscura, but answers quite
well for taking drawings from dried plants, or for copying
prints, &c. Its great recommendation is, its cheapness,
and the facility with which it can be prepared. The price
of the bichromate of potash is 2s. 6d. per lb., whereas,
of the nitrate of silver, only half an ounce can be obtained
for that sum. The preparing of paper, with the salts of
silver, is a work of extreme nicety, whereas, both the
preparing of the paper with the bichromate of potash, and
the subsequent fixing of the images, are matters of great
simplicity ; and I am therefore hopeful, that this method
may be found of considerable practical utility, in aiding
the operations of the lithographer. — Jameson's Journal^
Apiil to July, 1839
GLOSSARY.
Many words, not contained in this Glossary, will be found de*
fined or described, in the body of the Work, in their proper places.
For these, see Index.
Acescent, becoming sour.
Acetate, a salt, containing acetic acid.
Acetic acid, a vegetable acid which exists in vinegar.
Acetous, having the character of vinegar.
Acetous fermentation, the fermentation which produces vinegar.
Acicular, shaped like needles.
Acid, a substance, or fluid, which turns vegetable blues to a red, and
forms saline compounds with alkalies, &c. Most of the acids con-
tain oxygen.
Albumen, a. fluid found in living bodies, which coagulates by heat.
White of egg is an example.
Alkali, a substance in chemistry, which turns vegetable blues to a
green, and combines with acids, forming salts.
Alloy, a compound of different metals.
Alumine, an earth, which exists in clay, alum, &c.
Aluminium, a metal, which is the basis of alumine.
Amalgam, a compound of mercury with another metal.
Ammonia, volatile alkali.
Amorphous, not having a determinate or certain form.
Argillaceous, containing clay, or resembling it.
Argillaceous schist, common slate.
Arseniuret, a compound with arsenic.
Barilla, the ashes of certain maritime plants.
Barometer, an instrument for measuring the weight of the atmosphere.
Base, an ingredient in a chemical compound. Thus, sulphuric acid is
found combined with various bases, such as soda, magnesia, &c.
Bichloride, a double chloride. A compound, having two proportionals
of chlorine.
Boracic acid, a compound of oxygen and boron, which last is a simple
combustible substance.
Borates, compounds of boracic acid with a base.
Brake, or Break, a lever, which is occasionally pressed down upon the
wheel of a carriage, to retard its velocity.
Bromide, a compound of bromine and some other substance.
Bromine, an elementary substance, related to iodine and chlorine, and
found in sea water.
370 ' GLOSSARY.
Camera lucida, > optical instruments, by which the images of ob-
Cainera obscura,) }ects, as, for example, buildings or trees, are
thrown upon a paper, or other plane surface.
Carbonaceous, containing carbon or coal.
Carbon, a simple inflammable body, forming the principal part of wood
and coal, and the whole of the diamond.
Carbonate, a compound or a salt, containing carbonic acid.
Carbonic acid, a compound gas, consisting of carbon and oxygen. It
has lately been obtained in a solid form.
Carbonic oxide, a gas composed of carbon combined with the smal-
lest quantity of oxygen.
Carbojiization, conversion into coal.
Carburetted hydrogen, a gas, composed of carbon and hydrogen ; as
coal gas.
Carburet, a name given to certain compound substances, of which
carbon forms a part.
Caseous, having the consistence of cheese.
Centre of gravity, that point in a body, about which all the parts are
equally balanced.
Centrifugal, tending to fly off" from the centre.
Chloride, a compound of chlorine and some other substance.
Chlorine, a simple substance, formerly called oxymuriatic acid. In
its pure state, it is a gas, and, like oxygen, supports the combustion
of some inflammable substances.
Chromate, a combination of chromic acid.
Chromium, a brittle metal, of a yellowish white color.
Chromic acid, an acid of which chromium is the basis.
Chromate, a compound of chromic acid with some other substance, or
base.
Clay schist, common slate.
Cohesive attraction, the force by which the particles of a body cohere
together.
Coluber, a snake, having plates on the belly and scales on the tail.
Comparative anatomy, the science which treats of the structure of
other animals, compared with that of man.
Concentric, having the same centre.
Conic sections, the curves produced by cutting across a cone, in diff*er
ent directions.
Cupreous, containing copper.
Cycloid, the curve described by a point in the circumference of a cir-
cle, \^hile the circle rolls along a straight line.
Cylinder, a figure with circular ends and straight, parallel sides. A
round ruler and a wafer box are rough examples of the cylindrical
Debris, fragments, or remains, of disintegrated rocks.
Deliquescent, dissolving by fluid absorbed from the atmosphere.
Disintegrated, broken up or crumbling, for the most part, by the ac-
tion of air and moisture.
Eccentric, or excentric. This term is applied to a wheel, the axis of
which is not in its centre.
Effervescence, a motion resembling boilini;.
GLOSSARY. * 371
Efflorescence, the conversion of crystals into powder by the loss of
their water of crystallization.
Electro-magnetism, a science which shows the connexion of elec-
tricity and magnetism.
Epicycloid, the curve described by a point in the circumference of
one circle, while rolling upon the circumference of another.
Flange, or Flanch, a rim, or part projecting from the whole circum-
ference. Flanges are used in the wheels of rail-road cars, to pre-
vent them from slipping off the track ; also, at the ends of iron pipes,
to enable them to be screwed together.
Flocculent, resembling locks of down, or cotton.
Fluate of lime, or Fluor spar, lime combined with fluoric acid. At
Derbyshire, in England, it is found in crystalline masses, beautifully
variegated with purple.
Flush, even, or in the same surface.
Friction, the rubbing of surfaces together.
Friction rollers, little wheels, or cylinders, used to diminish friction.
Fulcrum, the point of support on which a lever rests.
Gallate, a salt, formed of gallic acid and a base.
Gallic acid, an acid obtained from nutgalls.
Gear, the teeth of wheels, by which one moves another.
Gelatin, an animal substance which is dissolved by hot water, ana
which forms common glue.
Geognostic, appertaining to a knowledge of the earth's structure.
Geological strata, the natural layers which are met with in penetra
ting the earth.
Gneiss, stratified granite.
Gobelins, the name of a celebrated manufactory of tapestry in Paris ,
so called, after two brothers of that name, who founded the manufac-
tory in the reign of Francis I.
Gravity, the general property by which bodies are attracted towards
each other, as seen in a stone falling towards the earth.
Graywacke, a kind of rock, of a gray or brown color, comp >sed of
grains and fragments of different materials.
HcBmatite, an ore of iron.
Hydrate, a solid compound with water.
Hydrate of lime, a solid compoimd of lime with water.
Hydraulics, the science which treats of the motion of fluids.
Hydraulic cement^ mortar, which hardens underwater.
Hydrochlorate, a salt containing hydrochloric, or muriatic, acid.
Hydrochloric acid, see Muriatic acid.
Hydrodynamics, the science which treats of the power or force of
water.
Hydrogen, a very light, inflammable gas, of which water is, in part,
composed. It is used to inflate balloons.
Hydrostatic pressure, the property of fluids by which they press
equally in all directions.
Hydrostatics, the science which treats of the pressure of fluids.
Hydrosulphuret, a compound of hydrogen and sulphur with another
body.
Hyperbola, one <f the conic sections.
372 * GLOSSARY.
Hyposulphite, a combination of hyposulphurous acid with a oase , as,
for example, with soda.
Inclination, slant, slope, or obliquity.
Inertia, the tendency which a body has to continue at rest, or to
move in a straight line, if it moves at all.
Infiltration^ the penetration of a fluid into the pores of a solid, as m
soaking.
Infusion, a solution of a vegetable substance, made without boiling.
Initial, that which exists at the first moment. Primary, incipient.
Inspissated, thickened, as when the juice of a plant is partly dried.
Iodine, a simple substance, of a grayish black color, and metallic lus-
tre, having a violet-colored vapor. It is obtained from marine
plants.
Iridium, a metal, found in minute quantities in the ores of platinum.
Kelp, the ashes of seaweed.
Larv(B, the name given to certain insects in their primary state, be-
fore they acquire wings ; as the caterpillar.
Litharge, an oxide of lead partly vitrified, or converted into glass.
Magnesia, a kind of earth, light and white, with alkaline properties.
Malachite, an ore of copper.
Malic acid, a vegetable acid which exists in cider.
Minimum, the smallest quantity.
Momentum, the force possessed by a body in motion, made up of its
weight and velocity.
Muffle, a vessel resembling a little oven, placed in furnaces to contain
crucibles and other objects, which require to be protected from
smoke and ashes.
Muriate, a salt, containing muriatic or hydrochloric acid.
Muriatic acid, an acid, composed of chlorine and hydrogen ; called,
also, hydrochloric acid, and spirit of salt.
JVitrate, a salt, containing nitric acid.
JVitric acid, an acid composed of oxygen and nitrogen.
JVitrogen, or azote, a simple substance, which exists, in the form of
gas, in the atmosphere. It does not support respiration nor flame.
Ochre, an earth colored yellow or red by oxide of iro«.
Ochreous, containing ochre.
Orrery, a machine, constructed to show the motions of the heavenly
bodies.
Osmium, a metal, found in minute quantities in the ores of platinum.
Oxalic acid, a vegetable acid which exists in sorrel.
Oxidable, capable of being oxidized.
Oxidation, combination with oxygen ; as in the rusting and tarnishing
of metals.
Oxide, a compound (which is not acid) of a substance with oxygen : —
Example, ox'de of iron.
Oxygen, a simple and very important substance, which exists in the
atmosphere, and supports the breathing of animals and the burning
of combustibles.
Oxymuriatic acid, see Chlorine.
Parallelogram, an oblong square.
Parallelopiped, a solid body, of which the four sides are parallelo-
grams, and the two ends square.
GLOSSARY. .. 373
Piles, large wooden posts or timbers, driven into the mud, to st4ppo»^
bridges and other structures.
Piling engines, engines for driving piles.
Plasticity, the property or capacity of being moulded.
Pontoon^ a kind of flat-bottomed boat, used to support bridges, float-
ing machinery, &c.
Potass, an alkali, composed of potassium and oxygen.
Potassium, a light and very inflammable metal, discovered in potass,
by Sir H. Davy.
Power of a number, the product obtained by multiplying a number by
itself. The product obtained by the first multiplication is called the
square. If this be again multiplied by the same number, it gives
the cube ; and so on, for the higher powers.
Precipitation. When a substance, dissolved in a liquid, is afterwards
separated, in a solid state, by the addition of another substance, it
is said to be precipitated.
Purple of Cassius, a purple powder, precipitated from a solution of
gold.
Pyrites, a compound of a metal with sulphur, having a metallic lus-
tre, and often crystallized.
Pyritous, having the charactes of pyrites.
Pyrometer, an instrument for measuring high degrees of heat, as in
furnaces, &c.
Radicles, small roots.
Radius, a line drawn from the centre of a circle to its circumference.
Reticulated, resembling the appearance of a net.
Rhodium, a metal found in minute quantities in the ores of platinum.
Salt, a compound, produced by the union of an acid with a base.
Saturated solution, a liquid, holding so much of a substance dissolv
ed, that it can dissolve no more.
Scalpel, a dissecting knife.
Schist, or Schistus, slate.
Sector of a circle, a part contained between two radii and an arc.
The sector of a cylinder is a longitudinal part which bears the same
relation to the whole, as a sector does to a circle.
Silica, or silex, an earth which exists in flint, sand, &c.
Silicium, a metal, or simple substance, which is the basis of silica
Sinuosities, windings.
Soda, an alkali, obtained from the ashes of marine plants.*
Spar, a general name given to crystallized minerals.
Stanniferous, containing tin.
Stratification, disposal in layers.
Stratum, plural strata, a layer of earth, rock, or (ther mineral sud»
stance.
Striated, marked with fine parallel lines.
Sulphate, a salt, containing sulphuric acid.
Sulphur, or brimstone, a simple, inflammable substance, well knowa
Sulphuret, a compound of sulphur with another body.
Sulphitretted hydrogen, a gas, composed of sulphur and hydrogen.
Sulphuret of carbon, a compound of sulphur and carbon.
Sulphuric acid, an acid composed of oxygen and sulphur.
II. 32 XII.
374 GLOSSARY.
Summit level, the highest part of a canal, or rail-roacr.
Tangent, an external straight line, which touches, but does not cross,
a circle.
Tartaric acid, a vegetable acid which exists in wine.
Thermae, baths of the Romans, which were large and magnificent
buildings.
Thermal waters, warm or hot springs.
Thermometer, an instrument, for measuring heat.
Traction, the act of drawing a load. Draught.
Treenails, (pronounced trunnels,) the wooden pins which confine the
planking to the sides of vessels. Also, similar pins, employed for
other purposes.
Vacuum, empty space. A perfect vacuum is rarely, if ever, pro-
duced. The vacuum of the air pump, and that of the barometer,
are approximations only, in which some gas or vapor is present.
Vaporization, conversion into vapor, commonly at a boiling temper
ature.
Velocipede, a carriage with two wheels, one before the other, on
which a person rides, pushing himself forward with his feet.
Viaduct, a piece of masonry built across a stream or valley, to support
a road, or a rail-way.
Vice versa, the side being changed, or the question reversed.
Vitreous, glassy.
Water-joint, a movable joint, made so tight as to exclude water
INDEX TO VOLUME IL
A.
Accumulated veins, 284.
Adjustment of sails for windmills,
98.
Adzes, 246.
Aerial ascents in balloons, 49.
Aerostation, 48.
Ahaz, sun-dials in the time of, 187.
Aids to locomotion, 12.
Air, escape of, and of water,
through a hole, 88. See Atmos-
phere.
Air-boxes for water pipes, 140.
Air-pumps of steam-engines, 118.
Albany, facts as to, 309. Basin
of the Erie canal at, 310.
Albany and Schenectady rail-way,
cost of the, 325.
Alkalies, in glass, 248.
Alleghany Mountains, passes across
the, 331.
Alleghany rail-way, 299, 334.
Facts respecting the, 328. See
Rail-ways.
Alloys, of metals, 211. Of gold,
214. Experiments of Hatchet
and Cavendish with, 215, note.
With silver, 219. Brass, 223.
Bronze, 225. Gun-metal, 225.
Bell-metal, 225, 226. Specu-
lum-metal, 225, 226.
Alternate, or reciprocating, motion,
62.
Amalgams, 211. Gold extracted
by, 212.
Amboy and Camden rail-road,
322, 334.
American, enterprise, 298. Rail-
ways, 298, 299, 318, 334. Ca-
nals, 299, 301, 314.
Ancient coins, experiments on, by
Dize, 226, note.
Animal power, 82. Of men, 82.
Of horses, 84.
Animals, motion of, 9, 10.
Annealing, metals, 216, note.
Glass, 251.
Antimony, used for coloring glass,
258. Localities of, 287.
Appendages to steam-engines, 110.
Apron, 87.
Aqueducts, canal, 33, 304. Con
veying of water in, 135. Ro
man, 136.
Arbor, meaning of, 195, note.
Arch of the Schuylkill bridge, 22.
Archimedes' screw, 144.
Arcs, line of, described in walk
ing, 10.
Arkwright, Sir Richard, water
spinning-frame by, 168.
Arrago, experiments by, on steam,
102, note.
Arrangement of pipes, 156.
Arrow-headed character, 263.
Artesian wells, 275. Operations
in forming, 276. Cause of the
overflowing of, 276. Tools
used in digging, 277. Finish-
ing of, 278.
Artificial, fountains, 161. Gems,
258.
Artillery, metal for, 225.
Artois, overflowing wells in, 275.
Arts, of locomotion, 9. Moving
forces used in the, 81. Of con-
376
INDEX.
veying water, 135. Of com-
bining flexible fibres, 164. Of
horology, 187. Of metallurgy,
208. Of vitrification, 247. Of
induration by heat, 262.
Ascents in balloons, 49.
Assaying metallic ores, 210.
Athens, sun-dials on the Tower of
the Winds at, 188. Brick walls
of, 262.
Atmosphere, effect of, on overshot
wheels, remedied, 88. Pres-
sure of, upon steam, 101, 102.
See Air.
Atmospheric elastic force, 104.
Atmospheric engine of Newco-
men, 115, 120.
Atmospheric machines, 159.
Attaching of horses, 14, 18, 84.
Augusta and Charleston rail-road,
322. Cost of the, 325.
Axes, 244, 246.
Axis, meaning of, 195, note.
Axle, meaning of, 195, note.
Axletrees, 17.
B.
Babylon, the walls of, brick, 262.
Back-water, remedies for, 92, 93.
Bag pumps, 153.
Balance-wheels of watches, 191,
192, 203.
Ballast,of aship, 41. Of balloons,
48.
Balloons, 48. Ascents in, 49.
Baltimore and Ohio rail-way, 325,
335.
Baltimore and Washington rail-
way, 320, 335.
Band, 73.
Band wheels, 51
Bar-iron, 235.
Barker's mill, 96.
Barrels, of watches, 191,200,201.
Of clocks, 195, 197.
Barton's pistons, 122.
Basin of the Erie canal, at Alba-
ny, 310.
Baskets, plated, 222.
Batchelder, loom by, for weaving
twilled fabrics, 176.
Bath-metal, 224.
Baths, Parkes's metallic^ 244
Roman, of brick, 262.
Bailer, cotton, 169.
Batting cotton, 169.
Bayonets of couplings, 76.
Bead pumps, 157.
Beak iron, 245.
Beam, wind upon the, 39.
Beating, gold, 215.
Beet sugar, manufacture of, 339 ,
cleansing of the beet roots, 339 ;
rasping the beets, 341 ; extrac-
tion of the juice, 342 ; mode of
operating with the press, 343 ;
defecation of the juice, 343 ;
concentration of the juice, 344.
Clarifying, 344. Filtration, 346.
Belgium, rail-way in, 318.
Bell-metal, 225, 226.
Belt and segment, 71.
Bernouilli, oblique planes recom-
mended by, 42.
Berthier, alloy produced by,
242.
Besant's wheel, 93.
Bevel-gear, 56.
Biddery-ware, 229.
Binding, See Bookbinding.
Birds, the flying of, 10. Swim-
ming of, 11.
Biscuit, in pottery, 270.
Bismuth, localities of, 287.
Blades of cutlery, 245.
Blair's gap, pass through, 331.
Blanks, in coining, 219.
Blast, hot, in smelting furnaces,
233.
Blasting, with gunpowder, 134,
292. Tools of miners for, 290.
In mines, 292. Sawdust used
in, 293.
Blast-furnaces, 232.
Bleaching rags for paper, 184.
Blistered-steel, 240.
Block-tin, 229.
Blooms, 236.
Blotting paper, 184.
Blowing glass, 250.
Blow-valves, 118.
Boats, transferring, on canals, 36
INDEX.
377
Canal, 36. Powers in, which
act against the inertia of water,
42. Passenger canal, 306.
Bobbins, 171, 172.
Bohemia, rail-way in, 318.
Boilers of steam-engines, 108.
Strongest form for, 108. Flue,
108. In large low-pressure en-
gines, 109. Bursting of, 112.
Other forms for, 113. Mate-
rials for, 117.
Bologna-phials, 251.
Bonnet, glass fibres obtained by,
261.
Bookbinding, the process of, 185.
Cloth, 186.
Borers, use of, in digging Artesian
wells, 277. Used by miners,
290, 297.
Bosses, 245.
Bossut, on the inclination of float-
boards, 92.
Boston and Lowell Railroad, 319,
334.
Boston and Providence rail-road,
321, 334.
Boston and Worcester rail-road,
327, 334.
Bottle-glass, 252.
Boulton, coining machinery by,
220.
Bow of a ship, 38.
Bowing materials for hats, 183.
Boxes, pump, 148.
Brakes, retarding wheels by, 31.
Of a pump, 148.
Bramah, re-inventor of the hy-
drostatic press, 152. Lead
pipes by, 228.
Bramins, sun-dials among, 187.
Branca, engine of, 103, note.
Brass, composition of, 223. Man-
ufacture of, 224. Buttons, 224.
Pins, 225.
Brathwaite and Ericsson's steam-
engines, 113.
Breakers, in caniing machines,
170.
Breast-wheels, 85, 94.
Brewster, Dr., on the adaptation
of wheels to falls, 88, 7Wte.
32*
Brick-kilns, 264.
Bricks, ancient, 262. Modern,
263. Pressed, 263. Burning
of, 264.
Bridges, 21. Wooden, 21. The
Schuylkill, 22. Stone, 22.
Cast-iron, 23. Suspension, 23.
At Menai, 23, 125. Floating,
23.
Bridgewater, Duk3 of, tunnel in
the canal of the, 34.
British Queen steam-ship, 45.
Broadcloths, nap of, 182.
Broad glass, 251.
Broad wheels, 15.
Bronze, 225.
Brooklyn and Jamaica rail-road,
322,334. Cost of iron for, 324,
Sleepers on the, 324.
Brown's gas engines, 128.
Brush wheels, 58.
Brussels, watch-spring preserved
at, 190.
Brussels carpets, 178.
Buchanan, on the application of
human power, 83.
Buckets, of overshot wheels, 86.
Of chain wheels, 89. In breast
wheels, 95.
Buffalo and Niagara rail-road, 321,
- 334.
Burning, of bricks, 263, 264. Of
pottery, 269.
Burns, buckets of, in the overshot
wheel, 87. Method of getting
rid of back-water by, 92.
Bursting of boilers, 112.
Bushnell's machine for submarine
navigation, 47.
Buttery, on carbon in steel, 241,
note.
Buttons, manufacture of brass,
224 ; of the eye or shank, 224.
White-metal, 224. Brass-eyes
of pearl, 224.
Cables, 166.
Caledonian canal, 36.
Camden and Amh.y raiUway,
322, 334.
37S
INDEX.
Camera obscura, use of the, in
photogenic drawing, 356.
Cams, 63. Curves for, 64, note.
Canal boats, 36. On the Erie
canal, 305. Passenger, 306.
Canals, rail-roads and, 24. Feed-
ers of, 32. Embankments of, 32.
Aqueducts in, 33, 304. Tun-
nels for, 33. Gates and weirs
for, 34, 308. Locks in, 34,
303, 308. Economizing water
in, 35. Boats for, 36, 305,
306. Size of, 36. The Great
Dutch, 36. The Caledonian,
36. Languedoc, 37, 301. New
York, or Erie, 37, 300, 308,
315. In the United States, 298,
314 ; their extent, 299 ; routes
of the principal, 300. Historical
facts respecting, 301. Length of
the American, 301, 314 ; their
cross-sectional area, 302. Ve-
locity of wave in, 302. Dis-
similarity in American and Brit-
ish, 303. Suspension of the
American, in winter, 305; mode
of travelling on them, 306.
Slackwater-navigation in the
lines of, 307. Details respec-
ting the Erie, 308, 315. The
Morris, 311, 315. Table r«-
specting the United States', 314.
Eastern division of the Pennsyl-
vania, 315, 330.
Cannon, casting of, 239.
Cannon-balls, 234.
Cannon-pinion of watches, 206.
Carats of gold, 214.
Card-ends, 171.
Carding, 170.
Carpets, Kidderminster, 177, 178.
Venetian, 178. Brussels, 178.
Turkey, 179.
Carriages, 12. Retarding, 31,
note. Steam, 129.
Carronades, manufacture of, 239.
Cartridges, use of, in mining, 292.
Cartwright's steam-engine, 67,
122.
Case-hardening, 242.
Casting, the process of, 233.
Moulds for, 233. Chill, 234.
Of glass, 253. Of pottery, 269
Cast-iron, bridges of, 23. Con-
dition of, 233. Converted into
good steel, 246. Rails, intro-
duced, in Great Britain, 318.
Cast-steel, 241.
Cavendish experiments with al-
loys, 215, note.
Cayuga canal, 308, 315.
Cellular pumps, 157.
Cementation, of gold, 214. Of
steel, 240.
Cenis, Mount, and Simplon, 298.
Centre-wheel of a watch, 203.
Centres, line of, 54.
Centrifugal pumps, 146
Ceramic, crystallo, 260.
Chain, wheels, 88. Pumps, 157.
Chains of watches, 190, 191, 200,
201.
Chairs on rail-ways, 25.
Champlain canal, 308, 315.
Change, of velocity, in machinery,
60. Of direction, in motion,
74.
Chariots, 12. See Carriages.
Charleston and Augusta rail-way,
322. Cost of the, 325.
Chat Moss, rail-way across, 323.
Cheeks of rail-road chairs, 322
Chemung canal, 308, 315.
Chill-casting, 234.
Chinese, substitute for canal locks
by, 35. Working of pumps by,
157. Make ropes of woody
fibres, 166. Sun-dials known
to the, 187. Pakfong, or white
copper, 226. Drawings on por
celain by the, 270. Porcelain,
271. Magic porcelain of the,
273.
Choragic monument of Lysicrates,
265.
Chrome, used for coloring glass,
258.
Church, Edward, compilation
from a work of, on beet sugar,
339.
Circles, the moving of horses in,
while drawing, 85.
INDEX
379
Circular motion, 51. Distant, 59.
In Barker's mill, 96.
Circumferences, primitive, 54.
Clack valves, 122.
Clamps of bricks, 264.
Clarification of beet sirup, 344.
Clay, valuable properties of, 262.
Products from indurated, 262.
Pipe, 267
Claying-bars, 291.
Cleansing beets for sugar, 339.
Clepsydra, construction of the,
188. Invented in Egypt, 188,
note. Brought to Rome from
Athens, 188, note.
Clocks, 189. Water, 189. Gene-
ral principles of, 190. Maintain-
ing power of, 190. Weights of,
190, 195. Regulating move-
ment of, 191. Pendulums, 191,
195. Scapements of, 193. De-
scription of, 194. Going part
of, 194. Striking part of, 194,
197. Wheel-work of, 194.
Dial-work of, 194. Barrels of,
195, 197. Pallets in, 196, 198.
Hands of, 196. Hawksbill in,
198. Warning-pieces in, 198.
Close-hauled, 39.
Cloth-binding of books, 186.
Cloths, woollen, manufacture of,
181. Felting, 182. See Cotton.
Clutches to couplings, 76.
Coals, mechanical virtue of, 125.
Coal-strata, 279.
Cobalt, used for coloring glass,
258. Printing ware with the
oxide of, 270. Furnished to
Chinese potters, 270, note. Pla-
ces for finding, 287.
Coff'er-dams, 22.
CcfFer-valves of steam-engines,
117,
Coining, of silver and other me-
tals, 219. At the mint in Eng-
land, 220. Of medals, 220.
Coin=-posts, for canal-gates, 35.
Coins, experiments of Dize on an-
cient, 226, note. Copying, by
voltaic electrical engraving, 349.
Colcothar, polishing silver with,
219. Polishing cutlery with,
246.
Colors for staining glass, 256,
258.
Columbia and Philadelphia rail-
road, 321, 329, 334.
Combining flexible fibres, arts of,
164.
Combs in carding 'tnachines, 170.
Common pinion in watches, 205.
Common pumps, 147.
Compass, magnetic, used by mi-
ners, 289 ; dial of, 289.
Concentration of beet juice, 344.
Concretions, in geology, 280.
Condensation, application of steam
by, 104, 120.
Condensers, invented by Watt,
116, 120. Remarks on, 118,
120. Treadwell's, 121.
Condensing engines, boilers in,
108, 109. Construction of,
115.
Conducting water, 135. By aque-
ducts, 135. By water pipes,
136. By syphons, 141.
Conemaugh river, viaduct across
the, 332.
Cones, 60.
Consolidated mines, depth of the,
- 298.
Continued rectilinear motion, 73.
Contrate wheels , 56. Of watches,
203.
Convoys, retarding by, 31.
Copper, gold alloy, 215, and 215,
note. Gilding on, 216. Plating
on, 221. Extraction of, 222.
Mines of, 222. Working, 223
Tinning, 223. Articles made
of, 223. An alloy in brass,
223 ; in bronze, 225. White,
226. Used for coloring glass,
258. Places for finding, 286.
Copper pipes, 137.
Cordage, 155. See Ropes.
Cornwall, steam-engine at St.
Austle in, 125. Depth of minea
in, 298.
Cost of American rail-ways, 325,
326; of English, 325.
380
INDEX.
Cotton, manufacture of, 167; ele-
mentary inventions for the, 168.
Batting, 169. Ginning, 169.
Carding, 170. Drawing, 170.
Roving, 171. Spinning, 172.
Mule-spinning, 173. Warping,
174. Dressing, 175. Weaving,
175. Twilling, 176. Double
weaving, 177. Cross-weaving,
177.
Cotton rags, paper made of, 183.
Counterpanes, 180.
Couplings, 75. Clutches, or glands
to, 76. Bayonets to, 76.
Cranks, 59, 65.
Crockery-ware, 265.
Crompton, Samuel, invented the
mule, 169.
Crooked Lake canal, 308, 315.
Crossing points in rail-ways,
28.
Cross-weaving, 177.
Crown-glass, 249.
Crown-wheels, 56. Of watches,
204.
Crucibles, materials for, 265.
Crude-iron, 233.
Cruikshanks, on water from com-
bustion of gunpowder, 131.
Crutch scapements, 72.
Crystallo ceramie, 260.
Culverts under canals, 33.
Cupellation of gold, 21.3.
Cupels, described, 213.
Curb, in watches, 206.
Cursor, Papirius, sets up a sun-
dial at Rome, 188.
Curves upon rail-ways, 28.
Curves, for cams and wipers, 64,
note. In pipes, to be avoided,
139, 140.
Cut-glass he operation of making,
255.
Cutlery, 245. Grinding, 246. Pol-
ishing, 246. Setting, 246.
Cut-nails, 239.
Cutting glass, 256.
Cylinder-glass, 252.
Cylindrical wheels, 17.
Cyrrhestes, Andronicus, Tower of
the Winds erected bv, 188.
D.
Daguerre, description of photo-
genic drawing by, 350. See
Photogenic Drawing.
Damascus swords, 244, note.
Dams for slackwater-navigation,
306. Across the Schuylkill
307 ; the Hudson, 309.
Danforth's speeder, 172.
Danville and Pottsville rail-road,
325, 335.
Dartrigues, on devitrification, 259.
Davy, Sir Humphrey, on procuring
power from fluids, 128.
Dead pulleys, 76.
Dead water, 37.
Dectot, Mannoury, 144.
Deep cuts, 25.
Defecation of beet juice, for sugar,
343.
De La Hire's pump, 151.
Dent, on a dissected watch, 208.
Deparcieux, M., on the line of
traction, 15. Experiments by,
on the inclination of float-boards,
92.
Depots of American rail-roads,
328.
Depth of mines, 297.
Derangements, in mineral veins,
285.
Desaguliers, on man's and horse's
power, 84.
Detonation of gunpowder, 130.
Devitrification, 259.
Dials, sun, 187. Of compasses
used by miners, 289.
Dial-work of a clock, 194.
Diamonds, in watches, 207.
Dilated, or flat, veins, 283, 284.
Direction, change of, in machinery,
74. Of a mineral plane, 280.
Disengaging machinery, 75.
Disengaging process, in photogenic
drawing, 358.
Dishing wheels, 16, 17.
Disseminated metalliferous sub-
stances, 282.
Distances, in the route from New
York to New Orleans, 300.
Distant rotary motion, 59.
INDEX.
381
Diving-bells, 45. Account of, 45,
46. Sensations in, 46.
Dize, experiments by, 226, note.
Doffing-cylinders, 170.
Doffing-plates, 170.
Double-acting engines, description
of, 116.
Double-acting pumps, 153.
Double-speeders, 171. Mechan-
ism of, 171.
Double-weaving, 177.
Draught, line of, 14, 18, 84. Of
a cotton machine, 171.
Drawing, by animals, 15, 18, 84.
Of cotton, 170. Wire, 238.
See Photogenic drawing.
Drawing-frames, 170, 171.
Draw-looms, 177.
Dressing, in weaving, 175.
Drops, Rupert's, 251.
Drymg of bricks, 262, 263.
Dry-rot, Kyan's preparation a-
gainst, 324.
Dublin and Kingstown rail-way,
319. Cost of the, 325, 326.
Ductility of glass, 260.
Dulong, M., on steam, 102, note.
Dust, on tram-roads, 29.
Dutch canal, the great, 36, 302.
Earth, means of penetrating into
the, 290 ; manual tools, 290 ;
gunpowder, 291 ; fire, 294.
See Mines.
Earthen, pipes, 137, note, 138.
Ware, 265 ; manufacture of,266.
Eccentric, wheels, 63. Pumps,
155.
Ecton mine, depth of, 298.
Edge rail-ways, 25.
Edges, silver, 221.
Eduction-pipes, 118.
Egyptians, the manufacture of
linen by the. 181. Sun-dials
known to the, 187. Clepsydra
invented by the, 188, note.
Glass among the, 261. Bricks
of the, 262. Sec-Pyramids.
Electrical engraving, voltaic, 348.
Elementary inventions for the cot-
ton manufacture, 168.
Elements of machinery, 50.
Eliquation of silver, 218.
Elongation, galleries of, 295, 297
Embankments of canals, 32.
Enamelling glass, 257. Enamels
for, 257. Colorbg materials
for, 258.
Enchasing, 215.
Endless screw, 57.
Engaging and disengaging ma-
chinery, 75.
Engines, gas, 128. Magnetic,
134. Fire, 162. See Steam-
engines.
England, Artesian wells in, 275
Wooden tram-roads introduced
into, 318. Cast-iron rails in-
troduced in, 318. Cost of rail-
ways in, 325.
Engraving, voltaic electrical, 348
Enterprise, American, 299.
Epicycloidal wheels, 69.
Equalizing motion, 76.
Ericsson's and Brathwaite's steam-
engines, 113.
Erie canal, 37,300. Length of
the, 300, 302, 315. Number of
boats navigating the, 305. Facts
respecting it, 308, 310, 315.
Basin of the, 310.
Etruscan vases, 273.
European porcelain, 271.
Evans, high-pressure expansion ei
gines of, 106.
Excavation, instruments for, 289.
Means of, 290 ; manual tools,
290 ; gunpowder, 291 ; fire,
294. Formsof the, to be made,
295. See Mines.
Expansion, application of steam-
power by, 106, 119. Of glass,
261.
Expansion engines, 119.
Expansiveness of water in steam,
100.
Explosions of steam-boats, 112.
Extraction, of metals, 209. Of
gold, 212. Of silver, 217. Of
copper, 222. Of lead, 226.
Of tin, 229. Of iron, 232
Of beet juice for sugar, 342.
Eyes of brass buttons, 224.
382
INDEX.
F.
Falls, adaptation of overshot
wheels to, 88, 7iote.
Faraday, experiments by, on steel,
241.
Faults, in mineral veins, 285.
Feed-pipes for steam-engines. 111.
Feeders of canals, 32.
Felting, hats, 182. Cloths, 183.
Fen-wheels, 163.
Ferrara, Andrew, tempering of
swords by, 244, note.
Ferry-boats, propulsion of, by
horses, 85.
Fibres, arts of combining flexible,
164. Woollen, 181. Of glass,
260, 261.
Filling of a web, 175.
Filtration of beet sirup, 346.
Finishers, in carding machines,
170.
Fire, employment of, in raining,
294.
Fire-arms, properties of, 132.
Fire-engines, 162.
Fishes, the swimming of, 10.
Swimming bladder in, 11, note.
Flanges on rail-way wheels, 25.
Flash-wheels, 163.
Flat, or dilated, veins, 283, 284.
Flax, reward offered for a machine
to spin, 180.
Flexible fibres, arts of combining,
164. .
Flint, use of, in glass-making, 248,
252. Glass ground with, 254.
In Wedgewood's ware, 268.
Flint-glass, 252. Moulding, 254.
Float-boards, propulsion of boats
by, 42. Affixed to a chain, 89.
In under-shot wheels, 90. Best
number of, 91. Position of, 91,
94. Breadth of, 92. In Be-
sant's wheels, 93. In Lambert's
wheels, 94. In breast-wheels^
95.
r'loating bridges, 23.
I loors, of tiles, 264.
Flue-boilers,in steam-engines, 108.
Fly, 78. In the striking part of a
clock, 197.
Fly-wheels, 78. Of steam-en*
gines, 117.
Flying, locomotion by, 10
Foil, tin, 229.
Followers, in moulds for pressing
glass, 255.
Force of gunpowder, 131.
Forces, see Moving Forces.
Forcing-pumps, 149.
Forged-iron, 235.
Forging, 235.
Forks, 245. Prongs of, 245.
Form of a ship, 37.
Formations, geological, 279.
Fountains, Hero's, 140, 159. Ar
tificial, 161.
Fourdrinier's paper-machine, 184,
185.
Fowling-pieces, manufacture of,
239.
France, canals in, 37, 301, 303.
IManufacture of porcelain in, 271.
Artesian wells in, 275. Rail-
ways in, 318.
Frenchtown and Newcastle rail
way, 320.
Friction, locomotion opposed by, 9.
Obviated, in walking, 10. Angle
for obviating, in drawing, 15,
18, 84. In machinery, 79
Of pipes, 138.
Frit, of glass, 250.
Fritting glass, 250.
Frost, prevention of, on rail-ways,
322.
Fuel, of engines, 125. Used on
rail-ways, 328.
Fulling cloths, 181.
Fulton, Robert, preferred planes
to canal locks, 35. Introduc-
tion of steam-navigation by, 42.
Experiments by, on submarine
navigation, 47. His torpedo,
48.
Furnaces, in steam-engines, 116.
Blast, 232. Puddling, 235.
Fusees of watches, 62, 191, 200—
202.
Fuses, used in blasting, 290.
Fyfe, on the Chinese pakfong,
226.
INDEX.
383
Gads, used by miners, 290.
Galena, 226.
Galleries, in mines, 295. Acceler-
ating the advance of, 296.
Gallic coins, experiments on, by
Dize, 226, note.
Gangues, of metals, 209. Of lodes,
282. Value of, to miners, 285,
288.^
Garnerin, M., parachute of, 49.
Aerial voyage of, 49, note.
Gas engines, 128.
Gates, in canals, 34.
Gathered, in glass-blovping, 250.
Gathering-pallet in a clock, 198,
199.
Gauge-cocks, in steam-engines,
111.
Gauze- vpeaving, 177.
Gay-Lussac, ascension of, 49, note.
Gear or gearing, meaning of, 53.
Spur, 53. Spiral, 55. Bevel,
56. Wheels thrown into and
out of, 76.
Gems, artificial, 258.
Generation, application of steam
by, 105.
Generators, in Perkins's engines,
113, note.
Geological formations, or deposits,
279.
Geology, value of, in investigating
mines, 287.
Geometry aids the miner, 289.
German silver, 226.
Germany, Artesian wells in, 275.
Gerstner, rail-way by, 318.
Gilding, on metals, 216. On por-
celain, 272.
Gilt wire, 217.
Ginning cotton, 169.
Glands of couplings, 76.
Glass, 248. Materials composing,
248. Metals of, 248, note.
Crown, 249. Fritting, 250.
Melting, 250. Blowing, 250.
Annealing, 251. Broad, 251.
Flint, 252. Bottle, 252. Cylin-
der, 252. Plate, 253. Casting,
253 Polishing plate, 254.
Ground with pure flint. 254.
Moulding, 254. Pressing, 255.
Cutting, 255. Stained, 256.
Enamelling, 257. Artificial gems
made of, 258. Devitrification
of, 259. Reaumur's porcelain
from, 259. Crystallo ceramie,
260. Thread, 260. Remarks
on, 261. Expansion of, 261.
Invention of, 261.
Glass globes, silvering the inside
of, 231.
Glass thread, 260.
Glass windows, 261.
Glazing ware, 267, 270.
Globes, glass, silvering the inside
of, 231.
Gneiss, metalliferousness of, 282,
283.
Gobelins, manufactory of tapestry
by the, 179.
Going part of clocks, 194.
Gold, 212. Extraction of, 212.
Cupellation of, 213. Parting,
213. Quartation of, 214. Ce-
mentation of, 214. Alloy in, 214.
Working, 215. Beating, 215.
Leaf, 216. Party, 216. Gilding
metals with, 216. Wire, 217.
Thread, 217. Improvements by
Stoddart, in gilding with, 217,
note. A coloring material for
glass, 258. Localities of,
286.
Gold-beating, 215.
Gold-leaf, 216.
Gold-lustre ware, 273.
Goldsmiths' work, 215.
Gold-thread, 217.
Gold wire, 217.
Governors, in steam-engines, 7b,
110, 117. In water wheels, 77.
In windmills, 99.
Grading rail-ways, 24.
Graduated semicircle, used by
miners, 289.
Granite, combustible fossils not
found in, 288.
Granite blocks, rail-roads on, 319,
323.
Gravity, an obstacle to locomotion,
384
INDEX
9, 11. Water and wind, appli-
cations of the force of, 85.
Great Dutch canal, in Hx)Iland,
36, 302.
Great Western steam-ship, Lieu-
tenant Hosken, commander of
the, 44, note. Size of the, 45.
Great wheel of a watch, 203.
Greek coins, experiments on, by
Dize, 226, note.
Gregory, Dr., on obviating friction,
15.
Grinding of cutlery, 246.
Gripes, in nail-machines, 239.
Grubbing rail-ways, 331.
Guanaxuato, depth of a mine in,
298.
Guard-gut of a watch, 202.
Gudgeons, meaning of, 195, note.
Gun-making, 239.
Gun-metal, 225.
Gunpowder, substitution of steam
for, 129. Manufacture of, 130.
Detonation of, 130. Force of,
131. Firing, 133. Blasting with,
134. Value and use of, in
mining, 291, 296. Augmenta-
tion of the effect of, 293. Saw-
dust with, 293.
Guns, steam, 129. Properties of,
132.
H.
Hair-springs of watches, 193, 204,
206.
Halsers, 166.
Hammers, tilt, used in iron-works,
236.
Hands of clocks, 196.
Hardening steel, 242.
Hargreaves, James, invention of
Iha spinning-jenny by, 168.
Haerlem rail-way, 321, 334.
Harness of a loom, 175.
Harnessing of horses, 14, 18, 84.
Hartz, depth of the shaft in the,
298.
Hatchet experiments with alloys,
215, note.
Hats, manufacture of, 182.
Hawk's-bill in clocks, 198.
Heart-wheels, 64. |
Heat, effect of, on pendulums, 192;
on glass, 261. Arts of indura-
tion by, 262.
Heathcoat's lace-machine, 178.
Heaved veins, 285.
Heddles of a loom, 175.
Hemp, ropes made of, 166. Spin-
ning, 167. Machines for spin-
ning, 167. Paper made of, 183.
Herculaneum, glass found at, 261.
See Pompeii.
Hero's fountain, 140, 159.
High-pressure engines, nature of,
105. Of Evans and Woolf, 106
Form of, 114. Operation of,
114. Steam-power applied to,
127.
High-temperatures, use of steam
at, 126.
Highs, Thomas, 168, note.
Highways, 19.
Holland, canals in, 36, 302.
Hollidaysburg canal, 315, 330
Railway from, to Johnstown,
332, 334.
Home, Sir Everard, on the loco
motion of serpents, 11.
Hooke's universal joint, 57.
Horizontal, wheels, 95. Wind
mills, 100. Scapements of time
keepers, 193.
Hornblower, application of expan
sive steam by, 120.
Horology, arts of, 187.
Horses, on attaching, to wheels,
14, 18, 84. The power of, 84;
compared with man's, 84.
Force and speed of, 84. The
drawing of, in circles, 85 ; on
revolving platforms, 85. On
American rail-ways, 328.
Hosken, Lieutenant, commander
of the Great Western steam-
ship, quotation from Redfield's
letter to, 44, note.
Hot blastjin smelting furnaces, 233.
Hot-pressed paper, 184.
Hour-hands of clocks, 196.
Hour-wheel of watches, 206.
Household pumps, 148.
Howth. diving-bell used at, 46
INDEX,
iSbb
Hubs of wheels, 16.
Hudson, dam across the, 309.
Human power, 82, 84. Buchan-
an on, 83. On estimatuag the
different applications of, S3.
Hungarian machines, 157.
Hydraulic rams, 160.
Hydreole, 144.
Hydrostatic press, 151.
I.
Inclination of a mineral plane, 280.
Inclined plane wheels, 55, note.
Inclined planes, canal boats moved
by means of, 35, 311.
Inclined planes and stationary en-
gines on rail-roads, 328, 332.
Machinery for working, 333.
Inclined shafts, in mining, 297.
Inclined wheels, 69.
Indian steel, experiments with, 241.
Indications of metallic mines, gen-
eral observations on the 285.
Negative and positive, 288.
See Lodes, Mines, Ores, and
Veins.
Induration by heat, 262.
Inertia, an obstacle to locomotion,
11.
Inland navigation of the United
States, 299.
Instruments used in subterranean
operations, 289. See Subterra-
nean.
Interlaced masses, 283, 285.
Inventions, elementary, for the
cotton manufacture, 168.
Iron, gilding on, 217. Plating on,
222. Articles of, tinned, 229,
Valuable properties of,
Extraction of, 232. Smelt-
232. Crude, 233. Cast-
233. Malleable, 235. For-
235. Rolling, 237. Slit-
ting, 237, 238. Wire-drawing,
238. Nail-making from, 239.
GuB-making, 239. Used for
coloring glass, 258. Places for
finding, 286. Ore, in America,
324.
Iron-hat,
II
230.
231.
ing.
ginS»
289.
33
Iron pipes, 137.
Iron rails, introduction of, 318.
America, 324.
Italy, Artesian wells in, 275.
Jamaica and Brooklyn rail-way,
322,334. Cost of rails and chaiVs
for, 324. Sleepers on the, 324.
Jenny, spinning, 168.
Jessop's pistons, 122.
Jewelling watches, 207.
Jews, sun-dials among the, 187.
Johnstown, rail-way to, 332, 334.
Joint, the universal, 57. The tog-
gle, 74.
Juniata rail-way, 325. Plan pro-
posed for the superstructure of
the, 326.
K.
Keel of a ship, 38.
Kidderminster carpets, 177, 178.
Kilns, for burning bricks, 264
For burning pottery, 269.
Kingstown rail-way, 819. Cost
of the, 326.
Kitspuhl mine, depth of, 298
Knee, or toggle, joint, 74.
Knives, 244, 245.
Kyan's anti-dry-rot preparation,
324.
L. ♦
Lace-machines, Heathcoat's, 178
Laces, 178.
Lachine canal, 301.
La Garousse, lever of, 74.
Lambert's wheels, 94.
Languedoc canal, 37, 301.
Lanterns to pinions, 54, 56.
Lap, cotton in, 170.
Lardner, on the power of the
steam engine, 124.
Lay of a loom, 175.
Lead, pipes of, 137, and 137, note,
227. Mineralized by sulphur,
226. Extraction of, 226. Man-
' ufacture of, 227. Sheet, 227.
Shot, 228. Places for finding,
286.
Leaf, gold, 216.
XII.
386
INDEX.
Leather, used about pumps, 1^3.
Leaves, of pinions, 54. In hed-
dles, 175.
Leeway of a ship, 41.
Lenticular masses, 280.
Leslie, on the force and speed of
horses, 84.
Lever, the universal, 74. Of La
Garousse, 74.
Lifting pumps, 152.
Lighthouses, American, 299.
Line, of traction, or draught, 14,
18, 84. Of centres, 54.
Linen rags, paper made of, 183.
Linens, 180. Machines for spin-
ning, 180. Manufactured by
the Egyptians, 181.
Live pulleys, 76.
Liverpool and Manchester rail-
way, locomotives on the, 80,
318. Crossing of Chat IMoss by
the, 323. Cost of the, 325. An-
nual expenses of the, 327.
Localities of ores, see Ores.
Locks, canal, 34, 303, 308. Sub-
stitute for, 35.
Locomotion, aids to, 12.
Locomotive engines, use of, on
rail-roads, 29, 318. Historical
facts respecting, 30. Premium
for, 30. Weight and power of,
30. Improvements in, 31. In-
ternal conduction of, 123. Op-
eration of, 124.
r.odes, 280. Origin of, 281. The
gangues in, 282, 285. Of four
species, 283. The rake-vein,
283. The pipe-vein, 283, 284.
Flat, or dilated, vein, 283, 284.
The interlaced mass, 283, 285.
Accumulated vein, 284. Faults,
or shifts, in, 285. See Mines
and Veins.
London, first paved, 20, 7ioie. Ar-
tesian wells in, 275.
Longitudinal galleries, 295, 297.
Looking-glasses, silvering of, 230.
Looms, 169, 176.
Low-pressure engines, boilers in,
108, 109. Construction of, 115.
Low temperature, use of vapors of,
127. Fluids boiling at, 127.
Lowell rail-road, 319, 334.
Lucas, conversion by, of toola
of cast-iron into good steel,
246.
Lustre-ware, 272. Gold and sil
ver, 273.
Lying heaps, 280.
Lyons, rail-way near, 318.
Lysicrates, choragic monument of,
265.
M.
McAdam roads, 20.
Machinery, elements of, 50. Ro
tary, or circular motion in, 51.
Distant rotary motion in, 59.
Change of velocity in, 60. Al-
ternate or reciprocating motion
in, 62. Parallel motion in, 65.
Rack and segment in, 70. Rack
and pinion, 70. Belt and seg-
ment in, 71. Scapements in,
71. Continued rectilinear mo-
tion in, 73. On engaging and
disengaging^ 75. Equalizing mo-
tion in, 76. Friction in, 79.
Moving forces of, 81. See Mov-
ing Forces.
Machines, 50. Remarks on sim-
ple and complex, 80. Zurich,
146. The Hungarian, 157. At-
mospheric, 159. For spinning
linen, 180. For manufacturing
paper, 184. For coining, 220.
See Machinery.
MTaggart, canal by, 305.
Magic porcelain, 273.
Magnetic compass, used in subter-
ranean operations, 289; the dial
of it, 289.
Magnetic engines, 134.
Magnetic iron-ore, 286.
Maintaining power of time-pieces,
190.
Malleability of metals, 235, 236
Malleable iron, 235.
IMan, power of, to produce motion,
82. See Human.
Manchester rail-way, see Iiiver
pool.
Manganese, used for coloring glass,
258.
INDEX.
387
Mangles, 71. i
Man-holes for steain-angines, 110.
Maple sugar, manufacture of, 337.
Marseilles quilts, 177.
Masses of mineral deposits, 280.
The interlaced, 283, 285.
Matrix of a metal, 209.
Medals, coining, 220. Of gun-
metal, 226, no^e. Copying, 349.
Melting the frit of glass, 250.
Melting-pots, materials for, 265.
Menai bridge, 23, 125.
Mercurial, or disengaging, process,
in photogenic drawing, 358.
VIercury, used in silvering, 230,
231., Places for finding, 287.
See Quicksilver.
Metallic baths, Parkes's, 244.
Metallic deposits, negative and
positive indications of, 288.
Metallic mines, general observa-
tions on the indications of, 285.
See Mines and Ores.
Metallic oxides, 249, 256.
Metallurgy, arts of, 208.
'Vietals, extraction of, 209. Na-
tive state of, 209. Mineralized,
or in the state of ore, 209.
Gangue, or matrix, of, 209. Sor-
ting, 209. Stampiag, 209.
Washing, 209. Roasting, 210.
Smelting, 210. Reducing, 210.
Refining, 210. Assaying, 210.
A-Uoys in, 211. Gilding on,
216. AnnerJ.ing, 216, .note.
Coining, 219. Platmg on, 220.
Gun, bell, and speculum, 225,
226. :>lould3 for casting, 233.
Meaning of the word, as ap-
plfed to glass, 248, note, 250.
Employed as coloring materials
for glass, 258. See Ores.
Mexico, depth of a mine in, 298.
Miea-slate, 232.
Milling coins, 219.
Mills, drawing in, by horses, 85.'
Barker's, or Parent's, 96.
Wind, 97. Post, 99. Hori-
zontal wind, 100. Fulling, 181.
Mineral veins, see Lodes and Veins.
Mineralized metals, 209
Mineralizer, 209.
Miners, distinction of mineral veins
by, 283. Aided by geology,
287. Means of, for penetrating
into the interior of the earth, 290.
Shovels of, 290. See Mines.
Mines, copper, 222, 286. Ure's
Dictionary on, 279. Indications
of metallic, 285. Geology a
guide in the investigation of,
287 — 289. Instruments em-
ployed in, 289. Tools used in,
290. Value and use of gun-
powder in, 291. Use made of
fire in, 294. Depth of several,
297, 298. See Earth, Excava-
tion, Lodes, Miners, Ores, and
Veins.
' Mint in England, 220.
Minute-hands of clocks, 196.
; Minute-wheels of watches, 205.
3Iirrors, silvering of, 230.
\ Mixed pumps, 151.
I Money, coinage of, 219.
I Montgolfier invented balloons, 48.
^Monument of Lysicrates, 265.
j Moody, Paul, 174, and l'^4, note
Moreys' engines, 123, 128.
3Iorris canal, 311, 315.
Motion, 51. Rotary, or circular,
i 51. Distant rotary, 59. Change
of velocity in, 60. Alternate,
I or reciprocating^2. Parallel,
i 65. Continuedrectilinear, 73.
i Change of direction in, 74. On
;j equalizing, 76. Rotary, in Bar-
' ker's mill, 96. Parallel, intro-
i duced into steam-engines, 122.
\Motion of animals, 9, 10.
I Moulding glass, 254.
Moulds, paper, 184. For casting
jj metals, 233. For glass, 254,
|| 255. For casting pottery, 269
' Saggars, 269.
Movement, the regulating, of time-
; pieces, 191.
I Moving forces used in the arts, 81;
kludge on speculum-metal, 226
Mule°s, 169.
|: Mule-spinning, 173.
ii Mummies, glass found with, 261
388
INDEX.
Murray's engine, 116, 123.
Muscular power, 82. Of men, 82.
Of horses, 84.
Muskets, manufacture of, 239.
N.
Nail, a rod used by, miners, 291.
Nail-making, 239.
Nap of broadcloths, 182.
Napoleon, reward offered by, 180.
National road, 331.
Native state of metals, 209.
Natural steel, 241.
Naves of wheels, 16, note.
Navigation, steam, 42, 45. Sub-
marine, 47. Inland, in Ameri-
ca, 299, 314. Slack-water, 306,
314.
Needles, polishing, 246.
Negative indications of metallic
deposits, 288.
Nests, in geology, 280.
Newcastle rail-way, 320, 335.
Newcomen's atmospheric engine,
115, 120.
New Orleans, see New York.
NewsUam's fire-engines, 163.
New York, route and distances
from, to New Orleans, 300.
New York canal, see Erie.
New York rail-way, see Haerlem
and Paterson.
Niagara andAiffalo rail-way, 321,
334,
Niokel, localities of, 287.
Nodules, in geology, 280.
Non-condensing engines, see High-
pressure engines.
Noria, 143.
No.ristown rail-road, 321.
O.
Oars, propulsion of boats by, 42.
Obstruction of pipes, 139.
Off-cast veins, direction of, 285.
Ohio rail-road, 325, 335.
Open trench, working by, in min-
ing, 296.
Open workings, in mining, 296.
Ores, 209. Locality of, 282, 285.
Value of geology for finding,
287. -See Mines.
Overflowing wells, see Artesian.
Overshot-wheels, 85. Pressure of
the atmosphere on, 88. Most
advantageous velocity of, 90.
Oxides metallic, 249, 256.
Pacos, 289.
Paddles, pro^^alsion of boats by,
42, 43.
Paddle-wheels, 42.
Painted glass, 257. See Stained
Pakfong, Chinese, 226.
Pallets, of scapements, 72. In
clocks, 196. Gathering, of a
clock, 198, 199.
Palmer, rail-way of, 27. On
dust on rail-ways, 29.
Pantheon, Rotunda of the, brick,
262.
Paper, materials for, 183. Man-
ufacture of, 183. Sized, 184.
Blotting, 184. Hot-pressed,
184. ^lachines for manufactur-
ing, 184. Rapidity of manufac-
turing, 185. Preparation of,
for photographic drawing, 365
Parachutes, 49.
Parallel motion, 65, 122.
Parent's mill, 96.
Paris, first paved, 20, note.
Parkes, metallic baths of, 244.
On supplying the Chinese with
cobalt, 270, note.
Parting gold, 213.
Party-gold, 216.
Pascal, hydrostatic press by, 151.
Passenger-boats, see Boats.
Passenger-cars, 329.
Passey, paper in the possession of,
185.
Passings, in rail-ways, 28.
Paste gems, 258.
Paternoster-work, 157.
Paterson rail-way, 320, 334.
Patterns, for castings, 233.
Pavements, 19. Wooden, 20. In
ancient cities, 20, note. Tel-
ford's, 20, 7wte.
Peace, Temple of, 262.
Pearl buttons, brass eyes of, 224.
Pearson, on gun-metal, 226, note.
[NDEX.
389
Pebbles, use of, in pavements, 20,
Pendulums of clocks, 191, 195.
Remedies for the effect of heat
on, 192. See Hair-springs.
Penknives, 244, 245.
Pennsylvania canal, 315, 328, 330,
331.
Pennsylvania State canals, travel-
ling'on the, 306.
Perkins, propelling wheel of, 43.
On getting rid of back-water,
92. Generators in the engines
of, 113, 7iote. Steam-gun by,
129. Inventions by, 129, note.
Perpendicular pits, 297.
Perpetual screws, 57.
Persia, ancient bricks in, 262,
Persian wheels, 143.
PeterhofF, fountains at, 162.
Phials, Bologna, 251.
Philadelphia rail-way, see Colum-
bia and Xorristown.
Photogenic drawing, 350, Prepar-
ing the plate for, 351. Coating
the plate for, 353. Use of the
camera obscura in, 356. Sea-
sons for, 357. 3Iercurial, or dis-
engaging, process in, 358. Fix-
ing the impression in, 360.
Talbot's experiments in, 362.
Ponton's method of preparing
paper for, 365.
Photography, 350. See Photo-
genic drawing.
Pick, used by miners, 290, 296.
Picker, cotton, 169.
Piercers, of cartridges, 292.
Piers, of bridges, 22.
Pig-iron, 2337
Piles, in rail-roads, 322, 323.
Pinchbeck, 224.
Pinion, 53. Leaves of, 54. Lan-
terns to, 54, 56. Rack and, 70.
In watches, 205. Cannon, 206.
Pins, 225,
Pipe clay, 267,
Pipe-veins, 283, 284.
P'lpes, steam, 117, Eduction, 118.
Water*, 136. Wooden, 137.
Iron, 137. Copper, 137. Lead,
137,227. Stone, 138. Earthen,
138. Friction of, 138. Quan-
tity of water conveyed in,
138, 139 . Velocity of water in ,
138, Size and form of, 138,
139. Curves in, to be avoided,
139,140. Obstruction of, 1.39.
Arrangement of, 156.
Pistons, of steanj-engnies, 117,
118, 122, 123. lor pumps,
151, 152.
Pitch lines, 54.
Pits, perpendicular, 297.
Pivots, meaning of, 195, yioie.
Planchets in coining, 219.
Planet wheels, 67,
Plate slass, 253.
Plated^ baskets, 222.
Plates, tin, 229, 230, 237.
Plating with silver, 220, 222.
Plunger pumps, 149.
Plyin^g cotton, 170, 171.
Po'interolle, 290.
Polishing, silver, 219. Cutlery
246. Plate glass, 254.
Poll of a pick, 290.
Pompeii, pavements in, 20, note.
Glass found at, 261.
Pompey introduces the clepsydra
into the Senate House, 188.
Ponton, 3Iungo, 365.
Porcelain, Reaumur's, 259. In-
gredients of, 265. Manufacture
of, 266. Drawings on, 270. Chi
nese, 271. Eultpean, 271.
Earths, in the United States,
272. Gilding, 272. Magic, 273.
Portage, see Alleghany.
Portland vase, 273. Imitated, 273.
Positive indications of metallic de-
posits, 288.
Post-mills, 99.
Potence, in a watch, 203.
Pottance, in a watch, 200, 203.
Pottery, 265. Operations in, 266
Glazing, 267, 270. Throwing,
268. Pressing, 269. Casting,
269. Burning, 269. Printing.
270. See Porcelain.
Pottsville rail-road, 325, 335.
Powder, see Gunpowder,
Power, sources of, 81, Vehicles
of, 81. x\nimal, 82. Water,
85, Viind, 97, Steam, 100
390
NDEX
Of the steam-engine, 124. Of
gunpowder, 130. The main-
taining, of time-pieces, 190.
Power-looms, 169, 176.
Powers acting within a boat, 42.
Precious stones, in watches, 207.
Press, hydrostatic, 151.
Pressed bricks, 263.
Pressingof glass, 255. Of pottery,
269.
Primary rocks, 279.
Primitive, radius, 54. Circum-
ferences, 54.
Prince's metal, 224.
Printing ware, 270.
Projecting water, 161.
Prongs of forks, 245.
Propelling power, on rail-ways, 29.
Propelling wheel of Perkins, 43.
Proportional radius, 54, 7iote.
Providence rail-way, 321, 334.
Proximate positive indications of
metallic deposits, 288.
Puddle for lining canals, 33
Puddling-furuaces, 235.
Pulleys, 76.
Pulp for paper, 184, 185.
Pumps, in steam-engines, 118.
Rope, 143. Spiral, 145. Cen-
trifugal, 146 Common, 147.
Household, or sucking, 148.
Forcing, 149. Plunger, 149.
De la Hi«s, 151. Mixed, 151.
Lifting, 152, Bag, 153. Dou-
ble-acting, 153. Rolling, 154.
Eccentric, 155. Chain, 157.
Bead, 157. Cellular, 157.
Punt, or punting-iron, 251, note.
Puppet valves, 121.
l*yramids, 125, 263, note.
Uuadrupeds, locomotion of, 10.
Swimming of, 11.
Quartation of gold, 214.
Ciuarter, wind upon the, 39.
Q,uicksilver, alloys of, 211. Ex-
traction of gold by amalgama-
tion with, 212. See Mercury.
Quilts, Marseilles, 177.
Quincy rail-way, 318, 334.
R
Rack, and segment, 70. And pin
ion, 70. Of a wheel in clocks,
198, 199.
Racks, 73.
Radius, 54, and 54, note.
Rag wheels, 52.
Rags for making paper, 183.
Rails, materials of, 25. Weigh*
of, 27. Introduction of cast-
iron, 318 ; of malleable iron,
318. In the United States, 324.
Rail-ways, object of, 24. Modern,
24. Compared with turnpikes,
and canals, 24. On the con-
struction of, 24, 323. The dif-
ferent varieties of, 25. Pas-
sings, or sidings, in, 28. Turn-
plates in, 28. Curves in, 28.
Crossing public roads, 29. Dirt
on, 29. Propelling power on,
29. Locomotives for, 29. Sta-
tionary engines, and inclined
planes on, 31, 328, 332. Am-
erican, 298, 299, 318, 334.
Foreign, 318. The sleepers
in, 324. Cost of American.
325, 326 ; of English, 32.5
Annual expenses of, 327, 329
Horses on, 328. Fuel, 328.
Grubbing, 331. Machinery for
working inclined planes on, 333.
Tables of, in the United States,
334—336.
Raising water, 142. See Water.
Rake-veins, 283,
Rams, hydraulic, 160,
Rasping beets for sugar, 341.
Ratchet wheels, 58.
Razors, 244, 245.
Reaumur, porcelain of, 259, On
glass thread, 260.
Receivers, in pressing glass, 255.
Reciprocating motion, 62.
Rectilinear motion, continued, 73.
Redfield, W. S., 44, 7iote.
Reduction of metals, 210,
Refining metal, 210,
Regulating movement of time-
pieces, 191
Regulator of a watch, 193
INDEX.
391
Remote positive indications of me-
tallic deposits, 288.
Rents, in geological strata, 281.
Reservoirs for beet juice, 342.
Retarding wheels, 31.
Rideau canal, 305, 307.
Roads, hints on, 19. Me Adam,
20. Loss of power on, 24.
The National, 331
Roasting ores, 210.
Robinson, Moncure, on the cost
of rail-ways, 325. Cited, 326.
Robison, John, on the overshot
wheel, 86. On the escape of
air and water through a hole, 88.
Describes a machine, 89.
Rocket engines, 30.
Rocks, 134. See Blasting.
Rollers, 13.
Rolling and slitting iron, 237.
Rolling pumps, 154.
Roman coins, 226, note.
Romans, aqueducts among the,
136. Windows among the, 261.
Rome, paved, 20, note. The first
sun-dial at, 188;, The clepsy-
dra brought to, 188, note.
Ancient bricks at, 262.
Roofs, covered with tiles, 264.
Rope-^umps, 143.
Ropes, 165.
Rotary, or circular,motion,51. Dis-
•tant, 59. In Barker's mill, 96.
Rotary valves, 121.
Rotative engines, 126.
Rotunda of the Pantheon, 262.
Rouge d' Angleterre, 246.
Routes of canals and rail-roads in
North America, 300, 314, 334.
Roving-frames, 170, 171. Sim-
pler form of, 172,
Ilovvutree's engines, 163.
Roy, on expansion of glass, 261.
Rubies, in watches, 207.
Rudder of a ship, 38.
Rupert's drops, 251.
Russel, on the velocity of wave in
canals, 302.
Russia, fountains in, 162.
S.
Safety gates in canals, 34.
Safety-valves, 112.
Saggars, 269.
Before the wind, 39
Sailing, 37.
Sails of windmills, 97. Angle for,
98. Adjustment of, 98.
St. Austle, steam-engine at, 125.
Sampson mine, shaft at the, 298.
Sand,formoulds,233. Inglas3,24S.
Sankey Brook canal, 301.
Santee canal, 301, 317.
Saratoga and Schenectady rail
way, 320, 334. Cost of the,325.
Sarcophagi, glass found on, 261.
Savannah, steam-ship, 44.
Sawdust, with gunpowder, 293.
Saws, 244, 245.
Saxony, the porcelain of, 272.
Scapements, 71. Pallets of, 72
Crutch, 72. Watch, 72. Of
time-pieces, 193, 200, 204.
Scape-wheels, 193, 204.
Schemnitz vessels, 157.
Schenectady, see Albany, Sarato
ga, and Utica.
Schists, gold found in, 286.
Schuylkill, bridge, 22. Slackwatei
navigation, 306, 316.
Scissors, 244, 245.
Scoop wheels, 142.
Scoria, 232.
Scotland, canal in, 36.
Screws, propulsion ^f boats by, 42
Perpetual, or endless, 57. De-
finition of, 74. Archimedes'
144. The water, 145.
Scudding before the wind, 39.
Secondary rocks, 279.
Segment,rack and.70 Beltand,71.
Semicircle, used by miners, 289.
Separating metal, 209.
Serpents, locomotion of, 11.
Setting the edges of cutlery, 246.
Severus, Alexander, Portland vase
discovered in the tomb of, 273.
Sevres, porcelain made at, 271.
Sewing-thread spun by mules, 174.
Shafts, to ventilate canal tunnels,
33. Means of, 195, note. In
mining, 295. Depths of, 297.
Shanks of brass buttons, 224
Shearing cloths, 182-
392
INDEX.
Shear-steel, 241.
Sheet lead, 227.
Sheldrake, T., inclit'.ed plane
wheels by, 55, note.
Shifts, in mineral veins, 285.
Ships, form of, 37. Bows of, 38.
Keels and rudders of, 38. Ef-
fects of wind on, 39. Stability
of, 41. Crank, 41. ToostifF,41.
Shooting tools of miners, 290.
Shot, manufacture of leaden, 228.
Shovels, miners,' 290.
Shrouds, 166.
Shuttles, 175.
Sidings, in rail-ways, 28.
Silesia, use of sawdust in, 293.
Silver, extraction of, 217. Eliqua-
tion of, 218. Working, 218.
Solder used for, 219. Polishing,
219. Alloyed, 219. Coining,
219. Milling, 219. Plating with,
220, 222. Edges, 221. Ger-
man, 226. Use of, for coloring
glass, 258. Localities of, 286.
Silvering of mirrors, 230. Of look-
ing glasses, 230. Of glass
globes, 231.
Silver-lustre ware, 273.
Silversmiths' work, 218.
Simplon and Mount Cenis, 298.
Singing cotton fabrics, ISO.
Single rail-wav'S, 27.
Size, of wheels, 13. Of canals, 36.
Sizing paper, 184.
Slackwater navigation, 306, 307.
In canals, 307, 314, 330.
Slag, 232.
Sleepers, used on rail-roads, 324.
Sliding valves, 121.
Slip, used in pottery, 269.
Slitting iron, 237, 238.
Sliver, cotton in, 170.
Slubbing machine, 181.
Smeaton, on muscular power, 84.
On the velocity of wheels, 90,
91. On float-boards, 91.
Smelting, metal, 210. Iron, 232.
Smifts, used in blasting, 290, 291.
Snails, water, 144. In clocks, 198.
Snifting-valves, 118.
Solder, for silver, 219. In pla-
ting copper, 221.
Sorting metal, 209.
Sources of power, 81. See Power
Sparry iron-ore, 241.
Speculum-metal, 225, 226, 230.
Speed, of steam-boats, 44, and
44, note. See Velocity.
Spencer, on voltaic electrical en-
graving, 348—350.
Spindle-rails, 171.
Spinning, mechanism of simple,
165, 168. Hemp, 167. Cotton,
172. Mule, 173. Glass, 260.
Spinning-frames, 168, 173.
Spinning-jenny, 168.
Spiral gear, 55, and 55, note. .
Spiral pumps, 145.
Spiral wheels and water-screws,
propulsion of boats by, 42.
Spoon, of the Zurich machine, 146.
Spouting wells, see Artesian wells.
Springs, of carriages, 17. Of
watches, 190,191,200,201,204.
Spur-gearing, 53.
Stability of a ship, 41.
Staffordshire, mine in, 298.
Stained glass, 256, 258.
Stamping metal, 209.
Started veins, 285.
State works, 300.
Stationary engines. See Inclined.
Steam, propulsion of vessels by,
42. Expansion of water, when
converted into, 100. Atnws-
pheric weight upon, 101, 102,
Increase of, after separation
from water, 101. Three meth-
ods of obtaining power from,
103. Application of, to engines,
114. Use of, at high tempera-
tures, 126 ; at low tempera-
tures, 127. Substitution of, for
gunpowder, 129.
Steam-boats, 42. Speed of, 44.
Steam-carriages, 129.
Steam-engines, 42. Cartwright's,
67,122. Governors in, 76, 110,
117. Estimation of the power
of, by horses' power, 84. Ear-
liest attempts at forming, 103.
Remarks on, 107. Boilers in,
108. Appendages to, 110
Brathwaite and Ericsson's, 113
INDEX.
S93
Application of steam to, 114.
Newcomen's atmospheric, 115,
120. Description of the double-
acting, 116. Expansion, 119.
Condensers in, 120. Valves of,
121. Pistons, 122. Parallel
motion in, 122. Estimates on
the power of, 124. At St.
Austle, in Cornwall, 125. Pro-
jected improvements in, 126.
Rotative, 126. See High-pres-
sure, Inclined plants. Locomo-
tive, and Low-pressure.
Steam-guages, 110.
Steam-guns, 129.
Steam-navigation, 42, 45.
Steam-pipes, 117.
Steam-power, 100.
Steam-ships, the Atlantic first cros-
sed by, 44. The Great Wes-
tern, 44, note, 45. The Brit-
ish Queen, 45.
Steel, gilding on, 217. Hardness
and tenacity of, 232. Iron re-
combined with carbon, 240.
The iron used in, 240, 241. Ce-
mentation of, 240. Blistered,
240. Tilted, 240. Shear, 241.
Cast, 241. Natural, 241. Al-
loys of, 241. Stodart's and
Faraday's experiments on, 241.
Indian, 241. Quantity of car-
bon in, 241, note. Case-har-
dening, 242. Tempering, 242.
Cutlery, 245. Conversion of
cast-iron into, 246.
Steps, in mining galleries, 296.
Stevenson, G., rocket-engine by,
30. On canals in North Ameri-
ca, 298. On rail-ways, 318.
Stodart, on steel, 241.
Stoddart, on gilding, 217, note.
Stone, bridges, 22. Pipes, 138.
Stones, factitious, employed by
the ancients, 263. Rail-ways
laid on, 319, 321, 323.
Stone-ware, manufacture of, 267.
Stop-gates, in canals, 34.
Stourbridge clay, crucibles of, 265.
Strainers, for water pipes, 139.
Strand of a rope, 166.
Stratiform deposits, 279.
Strength of man, 84, 150.
Stretching, the process of, 173.
Strikes, used in manufacturing
sheet-lead, 227.
Striking part of a clock, 194, 197.
Submarine navigation, 47.
Subteri-anean operations, instru-
ments for, 289. Wjrkings, in
mining, 296, 297. $ee Mines.
Sucking-pumps, 148.
Sugar, maple, 337. See Beet.
Sulphate of soda may be employed
in glass-making, 249.
Sulphur, lead mineralized by, 226.
Sun and planet wheels, 67.
Sun-dials, 187.
Superstructure for rail-roads, 326
Supporters of rail-ways, 319, 323.
Suspension bridges, 23.
Swab-sticks of borers, 290.
Sweden, copper mines in, 222.
Swimming, of fishes, 10. Of land
animals, 11. Of birds, 11.
Swimming bladders, 11, note.
Switch, in rail-roads, 28.
Swords, tempering of, 244, note.
Syphons, 141.
T.
Table, of canals in the United
States, 314 ; of rail-ways, 334.
Table-forks, 244, 245. Prongs of,
245. ^.
Table-knives, 244, 245.
Tail-water, remedies for, 92, 93.
Talbot, experiments by, 362.
Tamping, by miners, 291.
Tamping-bars, 291.
Tapestry, 179.
Taunton spindle, see Danforth's.
Taylor, on depths of mines, 297.
Teazles, 182.
Teeth of wheels, 53. The cut
of, 55, 56.
Telescopes, speculum-metal used
in, 225, 226, 230.
Telford, paved road by, 20, note.
Temperatures, use of steam at
high, 126; of vapors of low, 127.
Tempering steel, 242. By metallio
39'1
INDEX.
baths, 244. By Ferrara, 244,
note.
Temple of Peace, 262.
Tenders, see Locomotive.
Terra-cotta, 264.
Terre-cuite, 264.
Test-bars, 240.
Thames, bridges across the", 22.
Thenard, on steel, 242.
Theory of twisting flexible fibres,
164.
Thermae, of brick, 262.
Third wheel of a watch, 203.
Thread, gold, 217. Glass, 260.
Throttle-valves, 121.
Throwing, in pottery, 268.
Throwiug-wheels, 163.
Tides, velocity of, 44, note.
Tightening wheels, 76.
Tiles, 264.
Tilt-hammers, 236.
Tilted-steel, 240.
Timepieces, 189. Essential parts
of, 190. Maintaining power of,
190. Regulating movement of,
191. Pendulums of, 191. Bal-
ances of, 192. Scapemeuts of,
193, 200, 204. See Clocks and
Watches.
Tin, in bronze, 225. Extraction
of, 229. Block, 229. Foil, 229.
Plates, 229,237. Silvering with,
230, 231.- Localities of, 285.
Tin-foil, 229.
Tinning, copper, 223. Plates,
229, 230.
Tinstone, 229.
Toggle joint, 74.
Tombac, 224.
Toothed wheels, 53.
Torpedo, Fulton's, 48.
Tower of the Winds, 188.
Traction, line of, 14, 18, 84.
Train of a watch, 202.
Tram-roads, 27, 318.
Transition rocks, 279, 283.
Transit^ on rail-ways, 328.
Transverse galleries, 295, 297.
Trautwine, sections of rail by, 26.
Travelling, on canals, 306.
Tread well, on using steam, 113.
Condensers by, 121. Machines
by, for spinning hemp, 167.
Tredgold, 24, 43.
Trench, working by an open, in
mining, 296.
True radii, 54.
Trundles, in machinery, 54.
Tub-wheels, 95.
Tunnels, for rail-roads, 25. For
canals, 33. At Worsley, 34.
Turkey carpets, 179.
Turnpikes jnd rail-roads, 24
Turn-plates, on rail-ways, 28
Turn-tables, on rail-ways, 28.
Tweeled-cloth, 176.
Twilled fabrics, 176.
Twilling, 176.
Twisting, theory of, 164.
U.
Undershot wheels, 85, 90. Ve-
locity of, 91. Size of, 91.
Float-boards of, 91.
Universal, joint, 57. Lever, 74.
Utica and Schenectady rail-road,
327, 334.
Valenciana mine, depth of, 298.
Valves, in canal-gates, 35. Of
steam-engines, 112, 117, 118.
Different kinds of, 121.
Vapors of low temperature, 127.
Vases, 273.
Vehicles of power, 81.
Veins, 282. Rake, 283. Pipe,
283,284. Flat, or dilated, 283,
284. The interlaced mass, 283,
285. Shifts, or faults, in, 285.
Direction of offcast, 285.
Heaved, 285. Started, 235.
Exploring, 296. See Lodes
and Mines.
Velocity, change of, in machinery,
60. Of overshot-wheels, 90.
Of undershot-wheels, 91. Of
water in pipes, 138. In cotton
machines, 170.
Velvets, 179.
Venetian carpets, 178.
Ventilation of tunnels, 33.
INDEX.
395
Verge of a balance-wheel, 203,
207.
Vertical windmills, 97.
Vessels, Schemnitz, 157.
Viaducts, 25, 332.
Vitrification, arts of, 247.
Voltaic electrical engraving, 348.
W.
Wagons, 12. Retarding, 31, noie.
Wales, bridge in, 23, 125.
Walking, 10.
Ware, Biddery, 229. Wedge-
wood's, 265, 267. Earthen,
265, 266. Common crockery,
265. Glazing, 267, 270. Stone,
267. White, 267. Throw-
ing, 268. Pressing, 269. Cast-
ing, 269. Burning, 269. Print-
ing, 270. China, 271. See
Porcelain.
Warning-piece, in clocks, 198.
Warp, 175.
Warping cotton, 174.
Warping-machines, Moody's, 174.
Washing metal, 209.
Washington, see Baltimore.
Watch scapements, 72.
Watches, fusees of, 62, 191, 200
— 202. Essential parts of, 190.
Maintaining power of, 190.
Springs of, 190, 191, 200, 201
—204. Chains of, 190, 191,
200,201. Barrebin, 191, 195,
197, 200, 201. Regulating
movement of, 191, 206. Bal-
ances of, 191, 192, 203. Hair-
springs of, 198, 204, 206. Reg-
ulators of, 193. Scapements of,
193, 200. Description of, 200.
Wheel-work of, 200, 203.
Guard-gut of, 202. Train of,
202. Minute wheel in, 205.
Hour-wheel of, 206. Cannon-
pinion in, 206. Curb in, 206.
Addition of jewels to, 207.
Number of pieces in, 208.
Number of trades employed in,
208.
Water, movrnient of bodies
through, 3T. Dead, 37. Va-
riations in the fall of, 88. Great-
est effect of the action of, on
machinery, 91. Delivering, on
an undershot-wheel, ft2, 94.
Back, or tail, 92. On breast-
wheels, 94. On horizontal oi
«tub-wheels, 95. In Barker's,
or Parent's, mills, 96. Expan-
sion of, when converted into
steam, 100. For boilers of
steam-engines, 108. Arts of
conveying, 135. Subterranean
passages for, 136. Pipes for
transmitting, 136 Velocity of,
in pipes, 138. Obstruction of,
in pipes, 139. Conveyed in sy-
phons, 141. Raising, 142 ; by
the scoop-wheel, 142 ; by the
Persian wheel, 143 ; by the
noria, 143 ; by the rope-pump,
143 ; by hydreole, 144 ; by
Archimedes' screw, 144 ; by
the spiral pump, 145 ; by t!ic
centrifugal pump, 146 ; Lv
common pumps, 147 5 by the
forcing pump, 149 ; by the
plunger pump, 149 ; by De La
Hire's pump, 151 ; by the hy-
drostatic press, 151 ; by the
lifting pump, 152 ; by the bag-
pump, 153 ; by the double-act-
ing pump, 153 ; by the rolling
pump, 154 ; by the eccentric
pump, 155. Arrangement of
pipes for raising, 156. Raising
by the chain-pump, 157 ; by
Schemnitz vessels, or the Hun-
garian machine, 157 ; by He-
ro's fountain, 159 ; by atmos-
pheric machines, 159 ; by the
hydraulic ram, 160. Project-
ing, 161 ; by fountains, 161 ;
by fire-engines, 162. Lifted
and projected by throwing
wheels, 163. Rise of, in Arte-
sian wells, 276.
Water-clocks, 189.
Water-pipes, 136. See Pipes.
Water-power, 85.
Water-screws, 42, 145.
Water-snails, 144.
396
INDEX.
Water spinning-frame, 168.
Water-wheels, governors in, 77.
Watt, James, inventor of the sun
and planet wheel, 67. On a
horse's power, 84. Form of
boilers used by, 107. Conden-
ser invented by, 116, 120.
Double-acting engine of, 116.
Parallel motion introduced into
engines by, 122. Coining ma-
chinery by, 220.
Weaving, l''o. Double, 177.
Cross, 177.
Wedgewood, ware of, 265, 267.
Manufactory of, 267. Imitated
the Portland vase, 273.
Weft of cloth, 175.
Weight, animals draw through the
medium of, 15. Of rails for
rail-ways, 27. Of locomotives,
30.
Weights, raising of, by human
power, 84 ; by horse's power,
84. Of clocks, 190, 195.
Weirs, in canals, 34.
Wells, Artesian, 275.
Wheel-carriages, 12.
Wheel-work, of a clock, 194. Of
a watch, 200, 203.
Wheels, mechanical action of, 12.
Size of, 13. Attaching horses
to, 14, 18,84. Broad, 15. Form
of, 16. Cut of, 17. Perkins's
propelling, 43. Band, in ma-
chinery, 51. Rag, 52. Toothed,
53. Spiral gear, 55. Bevel
gear, 56. Crown, or contrate,
56. Universal joir.i instead of,
67. Perpetual screw, 57. Brush,
58. Ratchet, 58. Change of
velocity in, 60. Fusee, 62, 191,
200 — 202. Eccentric, 63. Cams
for, 63. Heart, 64. Cranks in,
65. Sun and planet, 67. In-
clined, 69. Epicycloidal, 69.
Rack and segment, 70. Rack
and pinion, 70. Thrown into, and
out of, gear, 76. Tightening, 76.
Fly, 78. Horses on, 85. Over-
shot, 85. Breast, 85, 94. Un-
dershot, 85, 90. Chain, 88.
Besant's, 93. Lambert's, 94.
Horizontal, or tub, 95. Scoop,
142. Persian, 143. Throwing,
flash, or fen, 163. Of clocks,
194. Of watches, 200—206.
For making ware, 266, 268.
White, inventor of the spiral gear,
55, note.
White-metal buttons, 224.
White ware, manufacture of, 267.
Wind, effect of the, on ships, 39.
Action of, on wind-mills, 97.
Windage, in guns, 132.
Windmills, vertical, 77. Hori-
zontal, 100.
Windows, 261.
Wind-power, 97.
Winds, Tower of the, 188.
Wipers, 64, Curves for, 64, 7iole
Wire, gilt, or gold, 217.
Wire-drawing, 238.
Wirtz, Andrew, machine by, 146.
Wooden, pavements, 20. Bridges,
21. Pipes, 137.
Woof, of cloth, 175.
Wool, remarks on, 181.
Woolf, engines of, 103, 106, 120.
Woolf's shaft, depth of, 298.
Woollens, 181.
Wootz, 241.
Worcester rail- way, 327, 334.
Working, of gold, 215. Of silver
218. Of copper, 223.
Worm, the, 57.
Worsley, tunnel at, 34.
Worsted, 181.
Wrought-iron, 235.
Wrought-nails, 239.
Y.
Young, Dr., spiral pump, used by,
146. On the greatest effect
produced by a laborer, 150.
Z.
Zinc, 223, 287.
Zurich machine, 146.
END OF VOL. li
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