• *
liftWi
Bl
L.R.I.
Vol. 33.
January 1809
129.
• -
Published lift Last Day of every Monlb, [PRICE 2s. Q ]
If -•;
55
THE
PHILOSOPHICAL MAGAZINE
CO MP HE H ENDING
THE VARIOUS BRANCHES OF SCIENCE,
THE LIBERAL AND FINE ARTS,
AGRICULTURE, MANUFACTURES,
AND
COMMERCE.
JEfa.
NUMBER CXXIX. For JANUARY 1809.
CONTAINING -LLC WING ENGRAVINGS:
M. James Elmes's Portable Bridj
Mr. Knight's new Method of training Fruit Trees j— and iell's Figure:? of the Comet of 1807.
BT ALEXANDER TIL L O C Ht
M.R.I. A. F.S.A. EDIN. AND PERTH. &C.
..'
LONDON.-
PRINTED BY RICHARD TAYLOR AND CO,, SHOE LANE:
\ndgoldby Richardsoksj Cadsll. and Daviesj Longman, Hurst, Bees, and Orme; Vernor, Hood, and Sharpe; Murray} Highleyj Sherwood andCo.j Harding; London : Bell and Bradfutb, and Constable and Co. Edinburgh: Brash andREiD, and 1). NlVEtf, Glasgow: and Gilbert and Hodges, Dublin.
:
m
ENGRAVINGS.
Vol. XXII. is Illustrated with a Quarto Plate containing magnified Rer presentations of the Parasitic Plant which causes the Blight in Corn : engraved, by P of the Right Hon. Sir Joseph Banks, P. U.S.
from the original Drawings. — A Plate containing Mathematical Figures to illustrate the best Form to he given to a Plough-ear; to illustrate a Paper by President Jefferson — A Portrait of Dr. Pries iley, from a Model taken from the Life. Engraved by E. Mackenzie — A nondescript Aquatic Insect, and microscopic Views of the Parts — Also Figures to illustrate a Paper on Elasticity — A Plate respecting the Physiology of Vegetables — Mr. Sepp: hod of vSuspending Ships — Figures to illustrate Messrs.
Humbuli! ry of Terrestrial Magnetism — Trie Hydromis
Coypou — The Yellow- b ' — The White bellied Hydromis.
Vol. XXLii. is illustrated with a Plate representing a Variety of the Genus Acarus — Mr. Davy's Apparatus for the Analysis of Soils — An Ap- paratus for the Use of Aquatinta Engravers, to prevent them from being annoyed with the Acid Fumes liberated in the Process — A Skeleton of the tian Ibis — The Planet Saturn, according to the Form ascertained by Dr. Herschel — A Portrait of. James Watt, Esq. F. R.S.; engraved by Mackenzie from an original Fainting — Machine to enable Shoemakers tq perform th<-.ir Work in a sian 1 ire — A Plate illustrating Dr. Her?
SCHEl's Paper on the Motions of the Heavens — Mr. Charles's Machine lor laying Land level — Apparatus for making Gaseous Oxide of Carbon.
Vol. XXIV. is embellished with a Plate of Figures to illustrate Mr. Dal- ton's Theory of the Absorption of Gases by Liquids — On the same ; — also a Refrigeratory for Distillation, acting on the Principle of the Syphon — The EtTects produced by Mr. Ez. Walker's newly invented Cometarium — A Quarto Plate illustrative of Experiments by Sir James Ha el, Bart., on the Effects cf Compression in modifying the Action of Pleat — Mr. Stee- vens's improved Gasometer, for Purposes where uniform Pressure is essen- tial— A Plate illustrating Mr. Walker's Paper on the apparent Magnitude of the horizontal Moon — A Quarto Plate illustrative of Sir James Hall's rimtflts on the Effects of Heat modified by Compression — A Portrait of Mr. Aueert: engraved by tVlr. E. Mackenzie- — A Quarto Plate of Na- tural History, viz. the Fishes EremqphiJus Mutisii, Astrobhpus Grixalvn, and Pimelodus Gyehpumi and a South American Monkey, the Simia leonina : engraved by Lowry.
Vol. XXV. contains an Octavo Plate illustrative of Experiments by S.ir James FI all on the Effects of Compression in modifying the Action of Heat — A Quarto Plate on the same Subject — A Quarto Plate to illustrate Sir James Hall's Paper on the Effects of Heat modified by Compression — .\']r. Salmon's improved Geometrical Quadrant, Level, and Calculator, for ascertaining inaccessible Distances on Land or at Sea. — M. Montgol- fier's new Calorimeter, for determining the comparative Quantities of Ca'oiic evolved by the Combustion of different Kinds of Fuel — Mr. Gil- bert Gilpin's improved Crane with Flexible Chains — Mr. 'Herbert's Book-case Bolt, and Mr. Le Caan's Check for Carriage Wheels on Rail- Roads — Salmon's Improvement on Canal Locks Figures to illustrate
M. Giiotthiuss Memoir on the Decomposition of Water by Galvanism — A Bust in Silex, found coated over with Chalcedony.
Vol. XXVI. is illustrated with a Quarto Plate of M. Le Roy's Chrono- meter— Mr. Syi.v b. her :s improved Air-Pump — A large Plate relating to Le Roy's Chronometer — An Octavo Plate on the same Subject — The Irish Canal Track-Boat — Mr. SteevenVs Autocratic Cock for large Reservoirs- Mr. V improved Pioton for Steam-Engines — -Another Plate relating to the same Snbj.jt.
Vol. 33.
February 1809.
No. ISO.
Published the Last Day of every Month, [PRICE 2s. 6d.]
THE
I PHILOSOPHICAL' MAGAZINE:
COMPREHENDING
THE VARIOUS BRANCHES OF SCIENCE,
THE LIBERAL AND FINE ARTS,
AGRICULTURE, MANUFACTURES,
AND
COMMERCE.
NUMBER CXXX. For FEBRUARY 1809.
CONTAINING THE FOLLOWING ENGRAVINGS:
Two Plates to illustrate Dr. William Richardson's Paper -S^on the Basaltic Surface of the Counties of Derry and Antrim : viz.
I. A View of Portmoon.
'f\'$L 2. A View of Pleskin, on the N. W. side of Bengore Pro- * montory.
BT ALEXANDER TILLOCH,
M.R.I.A. F.S.A. EDIN. AND PERTH. &C.
LONDON:
PRINTED BY RICHARD TAYLOR AND CO., SHOE LANE:
And sold by Richardson's; Cadell and Da vies; Longman, Burst, Rers, and Orme; Vrrnor, Hood, and Sharpe; Murray; Highley; Sherwood and Co.; Harding; London : Bell and Bradl-utr, and Constable and Co. Edinburgh: Brash andREin, and D. Niven, Glasgow : and Gilbert and Hodges, Dublin.
^wtffr*
ENGRAVINGS
Vot Will, is illustrated with a Plate representing a Variety of the Genus Acarus—- Mr. Davy's Apparatus for the Anal). —An Ap-
paratus tor the Use of Aquatinta l-ngravers, to prevent them from being annoyed with the Acid fumes l/berated in the Process — A Skeleton of the ;:in Ibis — Xhe Planet Saturn, according to the Form ascertained by Herschel — A Portrait of JampsWatt, Esq. F;R.S.: en
o'm an original Painting — Machine to enable Shoemakers to
• n their Work in a standing Posture — A Plate illustrating Dr. Hek-
, rtiona of the Heavens — Mr. Chm i tchine.
for laying Land level — Apparatus for making Gastous Oxide of Carbon.
Vol. XXI V. ia embellished with a Plate of Figured to illustrate Mr. Bal-
Theory of the ion of Gases by I iquids— -On the same; — also
a Refrigeratory for Distillation, acting on the Pri c'rple of the Syphon— The
s produced \>y Mr. Ez. Walker's newly invented Cometarium —
A Gtuarto Plate illustrative of Experiments by Sir Jamrs Hall, Bart., on
the Effects of Compression in modifying the Action of Heat — Mr, Stee-
's improved Gasometer, for Purposes where uniform Pressure is
tial A Plate illustrating Mr. WaLker's Paper on the apparent Magnitude
of the horizontal Moon — A Quarto Plate illustrative of Sir James Hall's ] rimeiHS on the Effects of Heat modified by Compression— A Portrait i : engraved by Mr. E. Mackenzie — A Quarto Plate of Na- tural History, viz. the Fishes Eremoph'tlui Mutisil, Astrobhpus Grixalvu, and lodus Cyclopum; and a South American Monkey, the Simla Icoiiina : engraved by Lowry.
Vol. XXV. contains an Octavo Plate illustrative of Experiments by Sir s Hall on the Effects of Compression in modifying the Action of
LTeat A Quarto Plate on the same Subject — A Quarto Plate to illustrate
Sir James Hall's Paper on the Effects of Heat modified by Compression
Mr. Salmon's improved Geometrical Quadrant. Level, and Calculator,
lining inaccessible Distances on Land or at Sea. — M. MoNTGOL- 's new Calorimeter, for determining the comparative Quantities of Caloric evolved by the Combustion of different Kinds Of Fuel — Mr. Gil- bert improved Crane with Flexible Chains — Mr. Herbert's Book -case Bolt, and Mr. Lk Caan's Check for Carriage Wheels on Raif-
p,.oads — Salmon's Improvement on Canal Locks Figures to illustrate
jM. Gkotthius s Memoir on the Decomposition of Water by Galvanism — A Bust in Silex, found coated over with Calcedouy.
Vol. XXVI. is illustrated with a Quarto Plate of M. Le Roy's Chrono- meter— Mr. Sylvester's improved Air-Pump — A large Plate relating to L« i' mometer — An Octavo Plate on the same Subject — The Irish
Canal Track-Boat — Mr. StREVENs'S Autocratic Cock for large Reservoir, — Mr. Wooi f's improved Piston for Steam- Engines — Another Plate relating to the same Subject.
Vol. X >'.\ II. is illustrated with a Quarto Plate of Mr. Stf.f.vkns's Com- pound er — Mr. Maslres's Fire-Escape — Mfc, Walker's new Optical Instrument called the Phant.ismtucopc — Mr. Ssodgk ass's Method ; Fmildings and Apartments by Means of Steam — Mr. Trotter's Curvilinear Rawing, and Mr. Hardje's Improved Book- :/s Stove for Heating Rooms, and Living vatious Articles — Figures illustrating the Manner of using Mr. • Instrument — Dr. Wollasion's Camera Luckla for IK in Perspective.
THE
PHILOSOPHICAL MAGAZINE:
COMPREHENDING
THE VARIOUS BRANCHES OF SCIENCE,
THE LIBERAL AND FINE ARTS,
AGRICULTURE, MANUFACTURES,
AND
COMMERCE.
BY ALEXANDER TILLOCH,
M.R.I.A. F.S.A. Edin. and Perth, &c.
" Nee aranearum sane textus ideo melior quia ex se fila gignunt, nee noster vilior quia ex alienis libamus uNapes." Just. Lips. Monk. Folit. lib. i. cap. i.
VOL. XXXIII.
For JANUARY, FEBRUARY, MARCH, arid APRIL, 1809.
L OND ON:
PRINTED BY RICHARD TAYLOR AND CO., SHOE LANE:
And sold by Richardson?; Cadell and Da vies; Longman, Hurst,
Kixs, md Orme; Vernor, Hood, and Sharpe; Murray;
Higulet; Sherwood and Co.; Harding; Loudon :
Bell and Bradfut£, and Constable and Co.
Edinburgh: Brash and rL?iD, and Niven,
Glasgow: & Gilbert & Hodges, Dublin. '
» •
^^>
MINERAL DEPT.
CONTENTS
OP THE
THIRTY-THIRD VOLUME.
RESULT of some Experiments on the Distillation of vari- ous Vegetable and Animal Substances .. .. 3, 116
Description of a Portable Bridge .. . 10
Analysis of some Iron Ores in Burgundy and Franche-Comte ; to which is added an Examination of the Pig Iron, Bar
Iron, and Sconce, produced from them 12
On Hydrophobia . . . . • . 24
On Deal Pendulum Rods 30
Method of hastening the Maturation of Grapes . . 32
New Method of training Fruit Trees 35
Proposed Improvement of the Hygrometer .. .. .. 39
Materials for a History of the Prussiates 42
Observations of a Comet, made with a View to investigate Us Magnitude, and the Nature of its Illumination . . 56
On Commerce .; ' .. 68
Memoir upon t/ie Vineyards and Wines of Champagne in,
France 77,142,227
Mr. Davy's Theory 86, 87
On Barometrical Measurements . . 97
A Letter on the Alterations that have taken place in the Structure of Rocks, on the Surface of the basaltic Coun- try in the Counties of Derry and Antrim . . 102, 194 Hydraulic Investigations, subservient to an intended Croo- nian Lecture on the Motion of the Blood . . . . 1 23 Analysis of the Schist that accompanies the Menilite near
Paris ., » 134
Comparative Analysis of some Varieties of Steatite . . 136
Method of painting Linen Cloth in Oil Colours, to be more
pliant, , durable, and longer impervious to Water, than in
the usual Mode 151
Experiments , on various Earths, undertaken with the View of ascertaining whether they are metallic Oxides .. 157 Proposal for altering the Scale of the Thermometer .. 166 On the Difference "between the Products obtained by Distil- lation of recent and of dried Vegetables . . . . 167 Report on a Manuscript Work of M* Andre, formerly Vol. 33. 1809, a known
CONTENTS.
known under the Name ofV. Chrysologue de Gy, en- titled A Theory of the actual Surface of the Earth. By MM. Hauy, Levierre, and Cuvter .. 170,312
Remarks on Hygrometry, and tlte Hygrometer oj J. Berze- lius 177
Hydraulic Investigations, subservient to an intended Croonian Lecture on the Motion of the Blood 182
On the Icy Crust formed on Glass Windows during a se- vere Frost . ♦ .. 191
A Letter on the Alterations that have taken place in the Structure of Rocks , on the Surface of the basaltic Coun- try in the Counties of Deny and Antrim . . . . J 94
Method of Preserving Fruit without Sugar . . . . 20S
Method of raising large Stones out of the Earth .. 214
Description of an Apparatus for making Carbonated Hydro- gen Gas from Pit Coal 217
Report of Dr. M. Garthshore and Patrick CoLarjHOUN, Esq., to the Society for bettering the Condition of the Poor 221
On the Affinity existing between Oxides of Carbon and Iron.
234, 273
Some Circumstances relative to Merino Sheep, ivilh Parti- culars respecting that great National Acquisition ; and also respecting the Sheep of the Flock of Negrete, imported from Spain 241,287
On the Motion of Floating Bodies 249, 300
Observations on a late Paper by Dr. Wm. Richardson, re- specting the basaltic District in the North of In' land, and on the Geological Facts thence deducible; in Conjunction with others observable in Derbyshire and other English Counties : with the Application of these Facts to the Ex- planation of some of the most difficult Points in the Natural History of the Globe 257
Analysis of the Mecanique Celeste ofM. La Place 264, 47 1
Description of a new Fence made of' tort clastic IV ire y which becomes invisible at a comparatively short Distance
270
On the native Gold Dust found in the Hills in (he Environs of the Commune of St. George, in the Department of Le Loire 281
Remarks on M. Burckhardt's Contrivance for shortening Reflecting Telescopes; with anew Method of making Re- fracting Telescopes with a Tube only one-third of the focal Length of the Object-glass 290
A Reply to Earl Stanhope, on his Defence of certain Prin- ciples and Fads erroneously stated in his Stereotyped
CONTENTS.
u Principles of the Science of Tuning Instruments with fixed Tones." . . . . 292
Memoir upon the Formation of the Phosphoric Ether, by Means of a particular Apparatus. By M. Boullay, Chemist, in Paris 302
Memoirs of the late Erasmus Darwin, M. D. . . 305
Observations upon Subterraneous Heat, made in the Mines of Poullaouen, and of Hnelgoat, in Br it any, in France 320
Method of ascertaining the Value of Growing Timber Trees, at different and distant P&riods of Time . . 327, 350
Report on the ponderous Flint Glass intended for the Ma- nufacture of Achromatic Glasses. Ptesented to the Insti- tute by M. Doufourgkrais • 337
Description of an improved Telegraph 343
Description of an Improvement in Jury Masts . . , . 346
Improvement in Anchors, to render them more durable and safe for Ships ; and an improved Mode of Fishing Anchors
348
On the intended Thames Archway between Rot her hit he arid Lirilehouse 372
On the Fibres used in Micrometers: With an Account of a Method of removing the Error arising from the Inflection of Light, by employing Hollow Fibres of Glass . . 383
Observations suggested by the Geological Paper of Mr. John Farey 385
Introduction to the Study of Mineralogy. By M. Hauy
38y, 45(>
A new Method for detecting Arsenic 401
On the present Mode tf finding the Rates of Timekeepers 402
Thoughts on Atmospheric Density and Pressure . . 417
On Geometrical Proptfi'tion 426
A few Hints concerning the Benefit that may be expected from the Nature of Coal Gas 432
On the fertilizing Properties of Manures which contain Ammonia .. .. .. ?. .. 43 S
Geological Observations on the Excavation of Valleys^ and local Denudations of the Strata of the Earth in particular Districts, &c, in Reply to Mr. Jqhn Carr's Letter in the last Number, p. 385 442
Contrivance for preventing Doors from Dragging on Carpets
448
Description of an Improved Screw Wrench to fit different- sized Nuts or Heads of Screws 450
On the Natural Causes which operate in the Formation of Valleys 452
Reply to Mr. Barlow's Article on Floating Bodies . . 4] 6
CONTENTS.
The Bakerian Lecture, An Account of some new analytical Researches on ths Nature of certain Bodies, particularly the Alkalies, Phosphorus, Sulphur, Carbonaceous Matter, and the Acids hitherto undecomposed ; with some general
Observations on Chemial Theory . . 479
On the Agency of Electricity on Animal Secretions . . 488 Keport of Surgical Cases in the City and Finsbury Dispen- saries for October, November and December, 1S0S„ With
the Dissection of' a singular Foetus 490
Proceedings of Learned Societies 88, 173, 250, 332, 408, 493 Intelligence and Miscellaneous Articles 91; 334, 41 2, 501 List of New Patents . . . . 90, 173, 253, 414, 502" Meteorological Tables . . . . 96, 176, 25(5, 336, 416, 50:>
THE
THE
PHILOSOPHICAL MAGAZINE.
I. Result of some Experiments on the Distillation of va- rious Vegetable and Animal Substances in the dry Way* By David Mushet, Esq.
J. he following are some of the experiments promised in my last communication to the Philosophical Magazine*.
Experiment I.
Haw Sugar. — 270 grains, being distilled till all volatile matter was separated, were found to have been reduced in weight to 38 grains, having lost 232 grains.
100 parts therefore contained: Volatile matter 85*9
Oxide of carbon 14*1
The charcoal obtained in this experiment was light and spongy, and possessed the most fascinating prismatic co- lours ; gold, purple, blues, and indigos. It occupied about three times the bulk it possessed when raw.
Experiment II. Loaf Sugar , single refined, 264 grains. — This in distilla- ion also swelled greatly in bulk, and discharged a pure white flame edged with blue. The coal had in forming en- tered into complete fusion, and resembled the former pro- duct, though not possessed of the same brilliant shades. — It weighed 39 grains. Loss by distillation 225 grains. Component parts of loaf sugar : Volatile matter 85*26
Oxide G*" carbon 1 4* 74
100 parts.
From these experiments it is evident that sugar possesses
* See Vol. axxii.
Vol. 33. No. 129. Jan, 1809. A 2 -similar
4 Some Experiments on the Distillation
similar properties with some varieties of pit-coal, in so far as it cakes or welds in distillation. (See Phil. Mag. vol. xxxii.)
Experiment III. White Silk Stuff, 200 grains. — These were distilled with a violent discharge of bituminous flame and smoke. The residuum was formed into a caked coal of a dense compact structure; cellular, though not in the least brittle. The colour was iron-gray, with a faint shade of copper. When struck, it was sonorous in a great degree. — It weighed 62 grains. Loss in distillation 138 grains.
Component parts : Volatile matter 69 Oxide of carbon 31
100 parts.
Experiment IV. Pure White Wool, 180 grains. — After being distilled, there was found a residuum coal of a dark shining gray colour, welded, or rather caked into one mass, adhering in part to the sides of the retort. — It was found to weigh 43 grains. Loss in distillation 137 grains.
Component parts : Volatile matter 76* 1 1 Oxide of carbon 23-89
100 parts.
Experiment V. Rice, very clean, 240 grains. — This substance distilled with a good deal of flame. The result was found to be a dense coal that had entered completely into fusion, and possessed no remains of the original grains of rice.-^-It now weighed 42 grains. Loss by distillation 198 grains. Component parts : Volatile matter 82*5 Oxide of carbon 1 7*3
100 parts.
Experiment VI. Barley, well dried, 200 grains. — This flamed violently, *nd burnt like coal or fat wood. The result was a firmly
welded
of various Vegetable and Animal Suh stances. 5
Welded mass of the same shape' w'y\h the interior of the re- tort. Each grain of barley preserved its' original form, but firmly welded to each other by a porous cement of silvery- coloured coal, which in some places was prismatic. — It weighed 38 grains. Loss in distillation 162 grains. Component parts : Volatile matter 81 Oxide of carbon 19
100 parts.
Experiment VIT. Eggs. — An egg was boiled hard and the shell taken off, the core was then allowed to dry till it had attained the con- sistency of a horse's hoof, which it greatly resembled. In this state it was found to weigh 333 grains. In distillation it yielded a great quantity of white flame of a dazzling colour. The residuum had passed by fusion into a silvery bright po- rous coal that weighed 21 grains. Loss by distillation 312 grains.
Component parts : Volatile matter 93-7 Oxide of carbon 6*3
100 parts.
Experiment VIII. Goose Feathers, 107 grains. — This substance in distilling yielded at first a heavy smoke, which was afterwards suc- ceeded by a pale blue flame. The residuum coal was un- commonly light and spongy. It had caked into one mass during the exposure, and now weighed 1 1 grains, having lost in distillation 96 grains.
Component parts : Volatile matter 90 Oxide of carbon 10
100 parts.
Experiment IX. Cork, in small pieces, 200 grains. — These united together and swelled into three times their original volume, similar to a caking coal. The charcoal obtained from this sub- stance, when pounded, was nearly ten times the bulk of
A3 common
6* Some Experiments on the Distillation
common vegetable charcoal. The mass was found to weigh 32 grains. Loss by distillation 168 grains.
Component parts : Volatile matter 84 Oxide of carbon 1 6
1 00 parts.
Experiment X. Horse-Hoof, 180 grains. — The coal afforded by the distil- lation of hoof was light, spongy, and of a silver- gray co- lour. It was formed by a perfect fusion of the pieces into one mass, and weighed 24 grains. Loss by distillation 156 grains.
Component parts : Volatile matter 86*6 Oxide of carbon 13-4
100 parts.
Experiment XI. White Horse Hair, 202 grains-. — This operation was car- ried on with a small discharge of flame. The hair was- found resolved by fusion into a light porous coal, of a silvery-gray colour, which weighed 28 grains, having lost by distillation. 1 74 grains.
Component parts : Volatile matter 86*13 Oxide of carbon 13-87
100 parts,
Experiment XII. Black Horse Hair, 200 grains yielded by distillation a very fine coal largely honeycombed, and of a silvery-gray colour, weighing 38 grains, having lost in distillation l.fi£*
grains.
Component parts : Volatile matter 8 1 Oxide of carbon 1 9
100 parts.
A portion of hair taken from the mane of the same horsey yielded of oxide of carbon 25"14 per cent.
The subjects of these experiments all afford coal, which
partakes
of various Vegetable and Animal Sulstances. J
partakes of the nature of welding or caking pit-coal, and most of them in distillation exhibited similar phaenomena.
The substances operated upon in the following experi- ments yield a carbonaceous residuum, more of the nature of wood, in so far as the original masses are seldom, or but slightly, altered in shape or appearance during the operation of distilling.
Experiment XIII.
Sivedish Turnip that had remained in the ground during the winter, washed clean, and separated from the skin, 500 grains, emitted during distillation a strong smell of vege- table matter, and towards the close of the operation a minute portion of flame. A fine prismatic coal was ob- tained which weighed 20 grains. — Loss by distillation 480 grains.
Component parts : Volatile matter 96 Oxide of carbon 4
100 parts.
The skins were distilled in a similar manner, and with a similar result as to coal. The product was only equal to 3-4 parts in 100.
Experiment XIV.
Potatoe. — A well washed potatoe dried, weighed 697 grains. After distillation, a beautiful prismatic coal was found. The original shape of the potatoe was still preserved, but the internal structure was materially changed ; a regular arrangement, of delicately coloured cavities h*d succeeded the vegetable organization, and the whole considerably re- sembled a honeycomb. The product was found to weigh 36 grains, having lost in distillation 661 grains.
Component parts : Volatile matter 94*83 Oxide of carbon 5*17
100 parts,
Experiment XV. Garden Beans, 330 grains. — In distillation these yielded a small portipn of grayish blue flame. The beans were found
A 4 possessed
8 Some Experiments on the Distillation
possessed of the same shape as when first introduced. They were quite detached from each other, contained "many line prismatic shades upon their surface, and weighed 40 grains. Loss in distillation 290 grains.
Component parts: Volatile matter 87 8 Oxide of carbon 12-2
100 pari
Experiment XVI. Common Field Pease, 2 40 grains, exhibited the same ap- pearances both durino- and after the distillation, and yielded of prismatic coal 48 grains, having lost in distillation 192 grains.
Component parts : Volatile matter 80 Oxide of carbon 20
loo parts.
Experiment XVII. Oats deprived of their husk, 240 grains. — A considerable portion of whitish blue flame was disengaged during the distillation. The grains were found in the state of coal, of a black coppery colour, free, and possessed of their original shape. — Weight of the coal oO grains. Loss in distillation 1 90 grains.
Component parts : Volatile matter 79' 16* Oxiue oi parboil ^lt84
100 parts.
Experiment XVI I L Flax, 397 grains. — After a copious discharge of white flame, a soft inflammable coal was found. The original vegetable fibre was entire, and equally compact as to shape and bulk as when first introduced. — It weighed 65 grains, having lost in distillation 332 grains.
Component parts: Volatile matter 83-6*2 Oxide of carbon 16-38
100 parts. Experiment
of various Vegetable and Animal Substances. 9
Experiment XIX. Cotton Cloth, well bleached, 263 grains.-— A considerable portion of pale blue flame was discharged during the opera- tion of distilling. A light friable coal was obtained, pos- sessed of the ordinal shape and texture of the cloth. — It was found to weigh 39 grains. Loss in distillation 124 grains.
Component parts : Volatile matter- 85*16 Oxide of carbon 14*84
100 parts,
Experiment XX. English Apple, cut into square pieces, 620 grains. — The distillation of this substance afforded but a small poftio F flame towards the clo,se of the operation. A light prismatic coai was ob'aincd. The shades chiefly blues with orange, and so vivid as to bear an intimate resemblance to the same colours upon policed steel. The individual masses were much shrivelled, but nxit in the least adhering together. — Weight 20 grains. Loss by distillation 600 grains.
Component parts : Volatile matter 96*77 Oxide of carbon 3 '23
100 parts.
Experiment XX F. Cinnamon, 150 grains. — This substance yielded a small portion of white flame edged with pale blue. The cnal was partially prismatic, but the shades were few, and dull in point of colour. It possessed no symptoms of welding or caking, and weighed 36 grains, having lost by distillation 1 14 grains.
Component parts: Volatile matter 76 Oxide of carbon 24
100 parts.
Experiment XXII. Sweet Almonds, 240 grains. — These in distilling dis* charged a great quantity of oily flame resembling the pro- duct of pit-coal. The almonds were found entire, and in
the
10 Description of a Portable Bridge.
the state of a prismatic coal. — Their weight was 33 grams, Loss in distillation 207 grains.
Component parts : Volatile matter 86*23 Oxide of carbon 13*75
100 parts.
[To be continued.]
II. Description of a Portable Bridge, invented hy Mr. James Elmes, Architect, of College-Hill, Queen-Street, Cheap side, London *.
JlSiudges upon this construction may be rendered either permanent or otherwise. The only difference will be, that for the former the parts may be strongly bohed and fastened together, instead of being joined by contrivances which ad- mit of the parts being separated, for the convenience of re- moval, as in the drawing now sent. (See Plate I.)
The component parts shall be first described, and after- wards the manner of applying them. A is a strong iron frame that forms the bottom. B is a square frame of the same metal, fastened by hinges, to the ends of A, for the purpose of falling down flat upon the bottom for conve- niency of packing, as shown by the figure C. A skirting of iron plate marked D, is also strongly fixed to the bottom, as in the elevation of the whole P, and in the figure B. Two spring catches are attached to this skirting to keep the sides steady when erected. One of these catches E on a larger scale is shown in the drawing'. The remaining detached parts are marked F and G. F is a square iron link separated in the middle, and each part opening by a spring. G is a kind of staple opening and closing by a double worm de- scribed round its superficies working in an interior screw, contained in a box, opening and closing very considerably by a single revolution of the box round the screw, by the means of a small handspike H.
* Communicated by the inventor.
As
Description of a Portable Bridge. 11
As many of each of the above described parts as are neces- sary, according to the width of the river or valley intended to be passed, with a sufficient quantity of planking posts, chains, &c, according to the existing circumstances of the case, are the whole of its component parts.
A bridge on this principle for a river, Sec, of a consider- able width is very portable ; for several of the square frames may be packed upon each other in carriages or waggons of the dimensions of eight feet three inches long, three feet four inches wide, and as many feet high as it may be wished to pack a number of frames ; two of them rising one foot. The links and staples can be packed in cases, each sort se- parate.
The method to be used in passing a river with this bridge shall now be described. (A valley is passed in the same man- ner ; but there being no water to pass, the bridge will be easier supported from the under side.) First, two sufficient holes are to be dug on one side the river, at the distance apart of the width of the bridge, which in this plan is nine feet, and the posts I, are first to be prepared with prongs, Sec, -as in the dotted figure K: next the four smaller ones L, properly secured and well rammed. Then taking any one of the pieces C, fix it on the posts I and L as drawn," and support it en two well driven piles, if the shore will permit : and hooking on the next piece with one of the links F through the eyes at the bottom of the piece, and one of the staples G, fixed into the holes of the upright piece or parapet, it will there hang. Several more are to be hanged on the same way, leaving under them, where necessary, barges or other craft, moored with supporters under them pro tempore. When completed to the opposite shore, the same process of fixing the posts, &e., is to be repealed, and when fastened to these posts, the under supports may be taken away, and the whole left suspending by itself. No- thing now remains but for the superintendant of the work to screw the staples, by the handspike II, till the brido-e rises by a small curvature by opening the interstices N at the top. It is not required to rise more than a small degree above level, only just enough to stiffen the whole, and cau*e
it
Analysis of Iron Ores, &c\
[ie like a stiff plank, and rather to occasion a thrust
than otherwise, which when the weight has
| may be again raised by the same operation.
ilks ace now to be laid on to meet at the intervals as
hnograpbic plan O, of which P is the elevation
ripletc. O is a perspective view of three joints looking
the bridge with the planks, &c, drawn faintly.
III. Analysis of some Iron Ores in Burgundy and Franchc- ComtC' ; to which is added an Examination of the Pig Iron, Bar Iron, and Scoriae, produced from them. By
M. \'Al*aUKLLN *.
In the year 1805, M. Vauquelin having visited various iron works in Burgundy, collected specimens of ores, pig iron, bar iron, scoria, and fluxes; intending to subject them to chemical analyses, to ascertain whether it might be possible to learn, from a comparison of their composition, what takes place in the processes to which iron ores and cast iron are subjected. The following are the principal results of this able chemist's labours, and the particulars of some of the processes he employed to obtain them.
I. Chemical Exaimnatmi of some Fluor Spars.
The spar used as a (lux at the mine of Drambon, -in the department of Cote-d'Or, is yellowish white, and tolerably hard. It dissolves with effervescence in nitric acid, and leaves a yellowish residuum, amounting to about a fifth of its weight, which is composed chiefly of fine sand, with a minute quantity of alumine and iron. The solution, which is colourless, gives with ammonia a light, fiocculcnt, semi- transpaienf, yellowish- white precipitate, in which was de- lected iron, a little alumine, and phosphate of lime. It likewise exhibited some traces of silex.
The spar of Pesine is compact, of a grayish white, and' dissolves in nitric acid, leaving a residuum of about a Iwen-
* From Journal det Minn, No. I 19 — being an abr'dgment of a paper 'given ux the Memoirs of the National Institute.
ticth
Analysis of Iron Ores, &c. 13
tieth of its weight. A little iron, alumine, and phosphate of lime, were found in the solution.
From these two analyses it appears, that the fluors ana- lysed consist almost wholly of calcareous matter, but that or Pesme is the most pure. They show at the same tune, that the stones examined contain a small quantity of phos- phate of lime, which certainly does not amount to a five- hundredth part.
II. Analysis of the Scoria? of the Iron Works at Dramhon. M* Vauqueiin began with these scoriae, rather than with the ores and smeltings, because these scoriae include more' foreign matters in a smaller bulk.
They have a shining blackish colour, nearly resembling some oxides of manganese. Their weight indicates that a considerable quantity of metallic matter is left in them. Some parts exhibit blebs of different sizes, others are com- pact. Their fracture is crystallized, either needly or laminar. Five grammes (77 grains) of scoria?, fused twice in suc- cession, with an equal weight of caustic potash, communi- cated to the alkali a very deep green colour, when the mass had been washed with water.^-This green colour is known to be an unequivocal proof of the presence of manganese, and it is the best method we can "employ to discover the slightest trace of this metal in any substance.
All the washings of the scoriae thus treated were put together, and boiled, to separate the manganese. In pro- portion as this took place, the liquor lost its green colour, and the metal floated in it in the form of brown flocks, which, when collected, washed, and dried, weighed two decig. (three grains) amounting to four per cent — The al- kaline liquor, freed from the manganese and filtered, still retained an orange yellow colour, which led M. Vauqueiin to suspect the presence of chrome.
To verify this suspicion, it was necessary, in order to facilitate the operations requisite for detecting the chrome, to separate the alumine and silex, that were in the alkaline lixivium : and to avoid the presence of muriatic acid, which would have thwarted the end he proposed, M. Vauqueiin
employed
Id Analysis of Iron Ores, &c.
employed very pure nitrate of ammonia, instead of the mu- riate. Thus be obtained two percent. (0*3 grains) of a mix- ture of silcx and alumine.
He next saturated the liquor with pure nitric acid, added a little in excess, and boiled it for a quarter of an hour, in order to dissipate entirely the carbonic acid.
To a portion of the liquor thus prepared he added a few- drops of the solution of nitrate of mercury at a minimum : but instead of yielding a red colour, as is usual with chrome, they threw down a white precipitate, which at first he took for muriate of mercury, but it afterwards appeared to be phosphate of mercury. — Instructed by this trial, he added to the remainder of the liquor limewater, which, when the aeid was saturated, produced a rloceulent precipitate. This had a slight tint of yellow, which changed to a green on drying, a circumstance that indicated some foreign matter in the phosphate of lime.
Anxious to discover the cause of this colour, he made the precipitate red-hot in a silver crucible ; but the green tint, instead of disappearing, became more intense. He then fused a little with borax by the blowpipe, and the fine eme- rald green colour which the salt assumed, confirmed his first suspicion of the existence of chrome in the scoriae from the refining furnace.
The remaining precipitate, being treated with nitric acid, did not entirely dissolve ; a portion being left of a very deep green colour, which was nothing but oxide of chrome mix- ed with a little silex, the particles of which being brought together and hardened by the heat had lost the capacity of being soluble.
The solution was colourless ; and oxalate of ammonia threw down from it a granulous precipitate, which, when washed and dried, weighed two decig. (three grains), and was true oxalate of lime.
The liquor from which the oxalate of lime was thus pre- cipitated, being evaporated to dryness, and the residuum ned, yielded an acid, which had all the properties of the phosphoric.
The first liquor, to which the limewater had been added
to
Analysis of Iron Ores, &c. 15
to precipitate the phosphoric acid, being mixed with nitrate of mercury recently prepared, a brown yellow precipitate was formed, which assumed a green tinge by drying in the air. This precipitate fused with borax gave it a very fine green colour, which proved it to be a chromate of mercury with excess of oxide.
The presence both of chrome and phosphoric acid in the scoriee from the refining furnace was thus demonstrated. These matters, as well as those that will be mentioned be- low, existed in the pig iron, and previously in the ore, for nothing was added during the processes of working them, from which these could have been produced.
After chrome, phosphoric acid, manganese, and a por- tion of the silex and alumine, had been separated, M. Vau- quelin dissolved in muriatic acid the ferruginous part, which had then a yellowish red colour. He observed, that, though the alkali had taken from it a great deal of oxide of manga- nese, a perceptible portion of oxygenized muriatic acid was produced, as the dissolution went on.
A white powder remained at the bottom of the liquor, which, when washed and dried, weighed 88 cent. (13-6 gr.), or about a fifth of the weight of the scoriae. During the evaporation of the liquor, which was carried to dryness, a portion of the same substance was precipitated, which was freed by means of muriatic acid from a little iron that fell down with it. This contained some traces of chrome, for it communicated to borax a decidedly green colour. It was silex.
M. Vauquelin precipitated the iron from its solution by ammonia, and added to the fdtered solution oxalate of am- monia, which formed in it a pretty copious precipitate of oxalate of lime.
The iron, still moist and in an attenuated state, was treat- ed with acetous acid, the mixture evaporated to dryness, and the residuum redissolved in water. In the clear and colour- less liquor was detected by different means the presence of oxide of manganese and of alumine, which had escaped the action of the alkali in the first operation, and of a pretty
large
16 Analysis of Iron Ores, &c.
large quantity of lime, which the volatile alkali had precipi- tated with the'help of" the oxide of iron.
From these experiments, and the results they furnished, it is evident, that the scoriae of the refining furnace, on which .they were made, are formed of, 1st, a larce quantity of iron oxided at a minimum ; 2d, oxide of manganese ; 3d, phosphate of iron ; 4th, chrome, probably in the state of oxide) 5th, silex ; 6th, aluminc; 7th, lime, part of which is perhaps combined with phosphoric acid.
A doubt can hardly be entertained, that all these matters were contained, at least in part, in the pig iron that fur- nished Ihe scoria? : the charcoal might have imparted to them at most some lime, silex, and manganese ; but the analysis of the ores, and .of the pig iron itself, will soon teach us what we ought to think on this point.
III. Examination of the Bog Ores* The ores subjected to analysis by M. Vauquelin were, 1st, those employed at the forge of Drambon. These are in spherical nodules of different sizes. Some irregular frag- ments of limestone are observed among them. 2d, those of Chamfont and Grosbois. These much resemble the former. Those of Grosbois contain a pretty large quantity of lime- stone. 3d, that of Chatillon-sur-Scine. This is of an ochrey yellow colour, in grains as small as millet-seed ; no lime- stone is seen among it, but it contains a pretty large quan- tity of clay,
M. Vauquelin gives at large his analysis of the ore of Drambon, observing, that the other ores include the same principles, though in different proportions ; at the same time the quantities he has assigned to its different component parts he gives only as approximations.
Ten grammes (154*5 grains) of the ore of Drambon, treated with caustic potash, assumed a very intense green colour, that communicated itself to the water in which it was lixiviated. The ore, on being subjected to the same ope- ration a second time, produced a similar effect, but less striking.
The
Analysis of Iron Ores, &c. 17
The liquors were boiled, and three decig. (4*6 grains) of manganese fell down, containing a little silex, and a minute, portion of iron.
The solution retained a slight yellow colour, as in that from the scoriae. M. Vauqueiin, supposing this colour to be produced by the same substance, saturated it with nitric acid. With this liquor he mixed a solution of nitrate of mercury made without heat; when it became colourless, and a white precipitate fell down, which did not give any tinge to glass of borax.
As the liquor contained an excess of acid, it was suspect- ed, that, if any chromate of mercury had been formed, it was held in solution. Accordingly a few drops of a solu- tion of pure potash were added, and a brown red precipitate was obtained, which, being fused with borax, gave in a fine emerald green. This indicated, that it was chromate of mer- cury, perhaps with a little phosphate of the same metal.
The liquor being still acid, and retaining some mercury in solution, M. Vauqueiin imagined it still contained chrome. He therefore added a few drops of nitrate of sil- ver, in hopes of obtaining a crimson red precipitate; but what fell down was of an orange yellow, and did not give a green colour to borax. It was phosphate of silver. Potash added to the remaining liquor produced a very bulky, floc- culent, lemon-coloured precipitate. This acquired a green hue as it dried, and was chromate of mercury, containing silver, with a small quantity of alumine and si lex,
The mercury was separated from the silver in a gentle heat by means of muriatic acid, diluted with two parts of water, that it might not dissolve the muriate of silver. At once the. precipitate became white, and the acid green. The solution being evaporated to dryness left a blackish matter, which gave a very fine green colour to borax.
Afterward, by employing sulphuric acid, and precipitating by limewater, M. Vauqueiin obtained 1 *5 per cent, of magnesia. Though this earth was found in the pig iron from each of the five bog ores, he does not venture to assert that it exists in all : but he observes, he has much more rea- t Vol. 33. No. J 29-. Jan. 1809. B so*
18 Analysis of Iron Ores, &c.
son to think that chrome and phosphoric acid are constantly found in it.
Reflecting that oxide of manganese, chrome, and mag- nesia, which he had just obtained, were found likewise in aerolites, or meteoric stones, he questioned whether it were not possible for iron ores to have contributed in some way or other to the formation of these stones. This idea led him to examine, whether nickel likewise did not occur in bog ores ; but his researches were fruitless.
From what has been said it follows, that the bog ore* analysed were composed of, 1st, iron; 2d, manganese; 3d, phosphoric acid; 4th, chrome; 5th, magnesia; 6th, silex; 7th, aluniine; and 8th, lime. The chrome, phosphoric acid, and magnesia had not before been noticed in these ores.
D
IV. Examination of the Iron thai sublimes and collects in the Chimneys of the refining Furnace.
This iron is found adhering to the sides of the chimneys of the refining furnace in the shape of stalactites, which are sometimes more than a foot long and three or four inches in diameter. They are formed of agglutinated grains, red in their fracture, leaving great intervals between them, and having but a slight action on the magnet.
We shall omit the particulars of M. Vauquelin's analysis, which he concludes with the following words :
" In this sublimed iron, then, there are oxide of manga- nese, silex, phosphoric acid, and above all a great deal of chrome. These matters therefore have been volatilized by the caloric, either by being dissolved in this fluid, or by yielding to the impulse of the current of air; but in either case they have issued from the pig iron during the process of refining/'
V. Examination of the Pig Iron of Dr ami on.
Having found oxide of manganese, chrome, phosphoric
acid, and earths, in the scoriae of the refining furnace, it
was natural for M. Vauquelin to infer, that he should find
the same substances in the pig iron ; since it is this that
furnishes
Analysis of Iron Ores, &c. 1 9
Furnishes these scoriae, at Jeast for the most part, in the pro- cess of refining. This fact was fully confirmed by analysis.
He proceeded thus. Ten grammes (154*5 grains) of gray pig iron of Drambon reduced to filings were dissolved in sulphuric acid diluted with six parts of water. The hydro- gen gas evolved during the solution was collected. It had an extremely fetid smell, very much resembling that of phos- phuretted hydrogen gas, though it had a certain pungency, which the phosphuretted hydrogen has not. The nature of this gas will be noticed presently.
The residuum was of a very deep black, and diffused an extremely strong smell of phosphorus. It weighed 53 cent. (8*2 grains), or a little more than a twentieth of the iron employed. The upper part of the bottle in which the solution was made, and the tube through which the hydro- gen had passed, being so greasy that water would not ad- here to them, M. Vauquelin suspected that oil had been formed ; a fact fist announced by M. Proust a few years ago on a similar occasion, and which M. Vauquelin adds he had himself observed before that, when dissolving certain kinds of tin. — To know whether any of this oil remained in the residuum of the pig iron dissolved in the sulphuric acid, he boiled it with highly dephlegmated alcohol, and filtered the liquor hot.
On the addition of water this alcohol became milky ; and being exposed to a gentle heat, drops of oil separated from it as the alcohol evaporated. This oil was clear and trans- parent; it had a slight yellow tinge ; its taste was hot and a little pungent. It appeared to be of a middle kind between the volatile and fat oils.
When the oil it contained was separated from the resi- duum of the pig iron, this residuum was deflagrated in a silver crucible with a little very pure nitrate of potash, the matter was washed with distilled water, and a light yellow liquor was obtained. This was mixed with a solution of the nitrate of ammonia, to precipitate the silex and alumine supposed to be contained in it ; and a small quantity of these was separated. Limewater added to the filtered liquor formed
B 2 in
20 Analysis of Iron Ores, &c.
in it a copious precipitate, which had all the characters of phosphate of lime.
To ascertain whether chrome was contained in this liquor, it was first boiled to volatilize the ammonia, and a few drops of nitrate of mercury were added, which was precipitated of a brown yellow, owing to a little lime remaining. This precipitate, however, gave a green colour to borax, which proves that it contained chrome.
The lixivium from the residuum of the solution calcined with nitrate of potash then contained phosphoric acid, chrome, and silex mixed with a little alumine. There was likewise in it a minute portion of manganese. — The resi- duum, when thus treated and lixiviated, was in the form of a reddish powder, which was dissolved for the greater part by muriatic acid. There remained, however, a small quan- tity of grayish matter, which was silex mingled with chrome, fbr it gave a very decided green colour to borax. — The mu- riatic solution contained a large portion of iron. It assumed the consistence of a jelly on evaporation, which proves that it contained silex. it is probable that a little chrome and manganese were also concealed in it.
It appears then that this pig iron, besides carburet of iron, contains phosphuret of iron, manganese, chrome, si- Jex, and alumine. Next jto the iron and carbon, it appeared to M. Vauquelin that the phosphorus was most abundant. It is then in the residuums of the solutions of pig and bar iron that we must henceforward look for phosphorus, rather than in the solutions themselves, as has hitherto been done. Probably the neglecting to examine these residuums with sufficient attention is the reason of our remaining so ignorant of the causes of the bad quality of iron.
M. Vauquelin admits that there is likewise a small quan- tity of phosphorus converted into acid, and dissolved in the liquor, probably in the state of phosphate of iron, by means of the sulphuric acid. It appears to him, that, when the sulphuric acid is less diluted with water, a larger quantity of phosphorus dissolves in the liquor. To separate this phos- phate of iron, he dilutes the solution with seven or eight
part*
Analysis of Iron Ores, &c. 21
farts of water, and mixes with it carbonate of potash, tilj almost the whole of the acid is saturated. A white preci- pitate is formed, more or less copious according to the kind of iron employed; and at the expiration of a few days it grows yellowish. This precipitate, washed and dried, he treats with potash in a silver crucible at a red heat : he then, lixiviates the matter with water, and, after having saturated the liquor with nitric acid, and boiled it to expel the carbo- nic acid, he adds hmewater, which commonly forms a white flocculent precipitate, or semitransparent if phosphorc acid be present. He has likewise found a large quantity of chrome in the precipitate produced by carbonate of potash in the solution of pig iron by sulphuric acid. It follows therefore, that chrome as well as phosphorus is oxygenized and dissolved in sulphuric acid.
The alkaline liquor should be tested with nitrate of am- monia, previously to saturating it, in order to know whether it holds any silex or alumine in solution. If it does, a suf- ficient quantity should be added to. precipitate these earths, after which they mu6t be separated by the filter ; as without this precaution they would be precipitated by the lime, and might be mistaken for phosphate of lime. M. Vauquelin has found very evident traces of this salt in the pig iron of the works at Drambon, though he employed sulphuric acid diluted with six parts of water to dissolve it ; there was much less, however, than remained in the residuum of the solution. This was the only kind of pig iron he examined, but he conceives it probable that all the irons from bog ores con^ tain the same foreign matters.
VI. Examination of the Bar Iron of Drmnhon and Pcsmes. M. Vauquelin dissolved five grammes (77*2 grains) of cold short iron of Drambon in sulphuric acid diluted with five parts of water. The hydrogen gas evolved during the dis- solution had exactly the same smell as that of the gas from the pig iron, but not quite so powerful. — The residuum left by these five grammes was much less copious than that of the pig iron, and appeared likewise not to be of so deep a black. While wet, it emitted a very strong fetid smell,
B 3 analogous
22 Analysis of Iron Ores, &c.
analogous to that of hydrogen gas. It weighed 15 cent. (-2-3 grains), amounting to three per cent. The solution of the iron had the same smel], which was not dissipated but by evaporation.
A kw particles of this residuum, thrown on a burning coal, emitted a white vapour, with a smell resembling that of arsenic and phosphorus. Heated red-hot in a silver cru- cible, it burned with flame, and left behind a yellowish powder. This was mixed with a little caustic potash, cal- cined, and lixiviated. The liquor being filtered, saturated- with nitric acid, and subjected for a few minutes to heat, limewater was added, which threw down a white fiocculent precipitate, consisting chiefly of phosphate of lime, but with a minute portion of silex, and perhaps of alumine.
It is certain from these experiments, which M. Vauquelin repeated several times, that the iron of Drambon, though it is considered as of pretty good quality, contains very per- ceptible traces of phosphorus. He likewise found some slight traces of it in the solution by sulphuric acid.
The iron of Pesmes afforded nearly the same results. The residuum, however, was less by one half, amounting only to lj per cent.; and it contained less phosphorus. This iron is very tough, and is reckoned one of the best in Franche-Comte.
VII. Of the Hydrogen Gas. Various experiments, which M. Vauquelin made by the help of oxygenated muriatic acid on the hydrogen gas evolved from the pig and bar iron, led him to conclude that phos- phorus is the chief cause of its fetid smell.
VIII. Recapitulation and Inferences. From the experiments I have related, says M. Vauquelin, it follows :
1. That the five sorts of bog ore I analysed are composed of the same principles, which, beside iron, are silex, alu- mine, lime, oxide of manganese, phosphoric acid, magne- sia, and chromic acid.
2. That the five sorts of ore having been taken without
selection
Analysis of Iron Ores, b'c. 23
selection from places tolerably distant from each other, it is probable that all ores of the same kind contain the same substances.
3. That these ores want only nickel, to contain the same substances as the stones that have fallen from the atmo- sphere.
4. That part of these substances remains in the bar iron, and probably in larger quantity in pig iron, which may be the cause of its greater hardness and brittleness.
5. That the greater part of these substances is separated during the refining of the pig iron, when this operation is well executed ; since they are found in the scoriae, and in the sublimed iron that adheres to the insides of the chim- neys of the refining furnaces.
6. That traces of them, however, are found in bar iron of good quality ; and that probably chrome, phosphorus, and manganese are the chief causes that render iron hot short or cold short.
7. '('hat the process of refining merits the greatest atten- tion from iron-masters, since it appears that the good quality of iron depends on its skilful execution.
8. That the presence of phosphorus and of chrome is to be sought for not in the solutions of pig and bar iron alone, but also in the residuums of their solutions.
9. That by the union of hydrogen and carbon during the dissolution of iron, and particularly of gray cast iron, an oil is formed, which, in conjunction with a small quantity of phosphorus, communicates a fetid smell to the hydrogen gas that dissolves them.
10. That it is to these two substances the hydrogen gas owes its properties of burning with a blue flame, and being heavier than when pure.
11. Lastly, That the oil and the phosphorus are separated from the hydrogen gas by oxygenized muriatic acid, which destroys them.
B4 IV. On
[ 21 ]
IV. On Hydrophobia.
To Mr. Tilloch.
SIR,
The following Paper, with some other MSS., lately fell into my hands. The Paper now sent appears to have been written se- veral years ago. If you think it worthy of insertion in your valuable Journal, it is very much at your service.
I am your very obedient servant, Greville street, John Taunton.
Jan. 10, 1809.
XVabies canina, or, as it is more commonly called, Hydro- phobia, the subject of the following dissertation, is a disease as little understood, yet as serious in its consequences, and dreadful in its effects, as any with which the human body is affected.
It may be defined a painful and difficult state of degluti- tion, attended with great anxiety and horror of countenance, with occasional convulsive paroxysms ; and these the conse- quence of the bite of a mad animal.
History of the Disease.
The symptoms take place at very irregular and uncertain intervals of time after the bite, having been known to occur as early as the third week, and as late as nine or twelve months ; but for the most part the commencement of the disease may be placed at four or six weeks from the time of the accident. In most cases, the first symptom is a painful and uneasy sensation in the part where the bite was in- flicted ; but this is not to be considered as a constant or in- variable occurrence.
Among the earliest appearances are to be ranked languor, depression of spirits, timidity, disturbed sleep, frightful dreams, sighing, and loss of appetite ; sometimes with nausea, weight at the stomach, and rigor.
In a short time the unhappy object becomes extremely sensible to all external impressions, the sense of touch, of hearing and seeing, being more or less affected in different cases. Upon attempting to swallow the smallest quantity cither of solids or fluids, but especially the latter, although
frequently
On Hydrophobia. 55
frequently excited to it by thirst, the greatest agitation and horror are produced, with an apparently strong convulsive affection of the pharynx and oesophagus, difficulty of breath- ing, tremor, great anxiety and impatience, and remarkable quickness of circulation.
The patient is not so much agitated by the sight of solids or fluids in the early state of the disease, as is commonly imagined ; watery liquors being sometimes carried to tho mouth with fortitude and composure ; but, immediately on touching the lips, are rejected with a violent and frightful agitation, the mind being at that time more particularly conscious of the inability of swallowing.
Solids are, notwithstanding, in some cases, got down, -even in the advanced stage of the disease, but never without pain and agitation, being thrust into the mouth in a pecu- liar hurried and greedy manner, and invariably exciting or in- creasing the convulsions, which constitute so formidable a part of the disease.
After these symptoms have continued 12, 18, or 24 hours (the progress being somewhat different in different cases), the disorder puts on the most distressing and melancholy appearance ; the convulsive attacks, which were before ex- cited chiefly by the attempt to swallow, now occur spon- taneously every 10 or 15 minutes, the whole body being so violently agitated as to require several assistants to support the patient. The countenance is wild, the eyes red and staring, and large drops of sweat pour from the head and face. In the intervals of these paroxysms, the miserable sufferer becomes somewhat composed, complains of an uneasy sen- sation across the breast, and also in the throat, often ascrib- ing it to wind, and wondering that he is not able to dis^ charge it, so as to obtain relief.
The secretion of saliva is now much increased, but of such a thick viscid quality, that the patient is obliged to exert considerable force to discharge it from his mouth. The manner of doing this, and the frequency with which it is repeated, joined to the peculiar anxious state of the coun- tenance already mentioned, so strongly characterize the disease, that the most superficial observer, having seen one
case
f<5 On Hydrophohla.
case of it, can scarcely afterwards be at a loss to distinguish another. As the disease draws towards a conclusion, the intellectual faculties, which had before remained wonderfully perfect, give way, the patient being affected with delirium of the fiercest and most unmanageable kind, especially du- ring the paroxysms of convulsion, which become so fre- quent as scarcely to have any interval.
The strength is at length exhausted; the pulse is extremely smalJ, weak, quick, and intermitting ; cold clammy sweats supervene; the countenance is somewhat livid and fright- fully distorted; and in this state a general return of convul- sion puts an end to one of the most melancholy and affect- ing scenes that the human mind can well form an idea of. This fatal termination happens most commonly about the end of the third day from the first attack, though it has sometimes occurred as early as the seeond, and at other times as late as the fourth day.
No anatomical examination that has hitherto been made on this subject, seems to have thrown any light upon it. Different parts of the fauces, pharynx, and oesophagus have been frequently found slightly inflamed, probably owing to the exertions to which these parts are subjected in the course of the disease. The lungs have also been generally found distended with blood, and in some cases the vessels of the brain likewise ; both of which may be supposed to depend on the irregular action of the heart. The only disease with which this is likely to be confounded is tetanus ; the painful and difficult deglutition, witri the convulsive paroxysms, being common to both ; but the continued stiffness of the jaws, or the spasm of the muscles by which the jaws are kept fixed, which is essential to tetanus, will at once lead to a satisfactory distinction, independent of the circumstances of infection, which we always annex to hydrophobia.
With regard to the theory of this disease, there are several important questions which naturally present themselves for consideration, each requiring a separate and perhaps exten- sive discussion, viz., To what is the origin of the infection to be ascribed ? To what animals is it confined ? Is any country exempted from it, and in what climates is it most
1 frequent ?
On Hydrophobia. 27
frequent ? Ts the infection confined to the saliva? Is ab- sorption necessary to the production of the disease ? At how late a period is the destruction of the part on which the bite was inflicted, effectual in preventing the disorder? Are the symptoms accompanied by a state of increased excitement, or by debility ?
The limits of this paper will not permit me to enlarge on these interesting topics ; but we may shortly observe, that, whatever may be the origin of the infection, it does not ap^ pear to be confined to any particular class of animals, or any particular country or climate ; that, with regard to absorption as necessary to the production of the disease, it is difficult to form a decided opinion ; for while on the one hand we have the analogy of other poisons, as that of lues venerea, in fi*- vour of absorption, we must observe on the other, that this disease bears a great resemblance to tetanus, where there is not the most distant suspicion of any thingkabsorbed to ac- count for the mischief; and further, that the lymphatic glands in the course of absorption have never, as far as I know, been found diseased.
Could this point be settled, we should have less difficulty in determining the next, namely, the period at which the de- struction of the part bitten would be effectual in preventing the occurrence of the disease; for, were it clearly shown to be produced by absorption, we should be inclined to think that the operation would be successful any time before the com- mencement of the pain in the part mentioned in the history.
As to the question whether the hydrophobia be a disorder accompanied by increased excitement or debility, it is ne- cessary to say, that, by increased excitement, I mean not only a greater frequency of action in the heart and arteries, but of strength likewise. In some cases of this disease, the symptoms seem to have indicated such a condition; as, for example, the rapid and apparently strong state of circula- tion, and the fierce and unmanageable delirium. Bleeding has seemed to be strongly indicated from these circum- stances, and has accordingly had a full and fair trial ; but the effects have by no means tended to confirm the idea on which the practice wa^s founded. The delirium and frequency
of
25 On Hydrophobia,
of circulation have rather, on the contrary, been increased by it. It is not unlikely, when we take a view of the action of the other poisons, that there may be a difference in differ- ent cases ; thus, the small-pox is sometimes attended with strong inflammatory symptoms; at other times with great debility ; and this difference not depending on any variety in the poison itself, but on the state of the constitution and other accidental circumstances. I am not able to determine how far the analogy will apply to hydrophobia. That it is sometimes connected with debility cannot be doubted, having occurred in delicate children, in whom the pulse has been weak throughout the whole of the disease. This weak- ness, too, must necessarily be increased by the unhappy state of deglutition, which precludes all nourishment by the mouth. There are several other circumstances also, which are fa- vourable to the idea of debility as connected with this com- plaint : thus, it is well known that some of the most violent convulsive disorders are attended with great debility, and the only method of removing them effectually, is by strengthening the constitution. Again, a fierce and very unmanageable state of delirium occurs in some cases of low fever, where every other symptom points out weakness, and the free use of wine at such times has produced the happiest effects. Although then it is far from my intention to pro- pose debility as explanatory of the symptoms of hydrophobia, yet it appears to be that condition of the body which most generally accompanies it, and which should not be lost sight of in the treatment.
Method of Treatment.
I have no hesitation in affirming, that there is no well- marked case of this disorder in which a cure has been ob- tained after the symptoms have made thtair appearance ; and even with regard to the prevention, that there is no method of treatment (that of removing the part excepted) which can in any degree be depended on.
The disorder has repeatedly occurred after the fullest trial of theOrmskirk and other boasted specifics. And no favour- able conclusion can be drawn from those, instances in
which
On Hydrophobia. 29
which patients having taken such remedied have escaped. First, because many bites are inflicted by animals which are not diseased, but only supposed to be so. Secondly, If the animal be decidedly mad, all of those on whom the bite is inflicted are not the subjects of the disease, some of them escaping independently of any medicine. \
After the symptoms have made their appearance, there are some remedies which appear to have had so full a trial, that their exhibition should be totally laid aside in future. Of these are the Ormskirk medicine, musk, mercurials, bleeding, warm bath, and opium ; and therefore, in con- ducting the treatment hereafter, I would propose in the first place, that we should seek for a specific among those articles of the materia medica which are known to exert strong effects upon the body. Among the metallic prepa- rations, I would more particularly recommend a trial of those- of lead, copper, zinc, and lastly of arsenic. Among the vegetables, tobacco, cicuta, aconite, henbane, &c. Several remedies of this description may be administered at the same time.
But while we are endeavouring in this way to find out a specific for the poison of hydrophobia, I would not neglect other objects, which appear to be of consequence, and which do not interfere with it. Thus, I should en- deavour to administer frequent clysters composed of broth, milk, and other nutritious articles. Various antispasmodics may be combined and employed in the same form, for it is in vain to expeet that the patient can swallow so frequently as would be necessary to the fair trial of such remedies. Camphor, asa foetid a, castor, aether, Sec, may all be com- bined in the form of clyster, and injected every second or third hour. When these different plans have been tried, if the disease should still baffle our endeavours, let us not continue tame witnesses of so melancholy a spectacle, but proceed to methods which no other situation could jus- tify— I mean that of injecting into the blood vessels va- rious active remedies, having previously tried upon animals (as some kind of guide) in what quantities they can be re- ceived
30 On t)cal Pendulum Rods*
ceived into circulation without fatal effects. If ihese should be found unsuccessful, to expose the patient for a certain length of time to one or other of the mephitic gases.
V. On Deal Pendulum Rods.
Lynn, Dec. 17th, 1808.
SIR) - To Mr. Tilloch.
XT has been frequently observed, that clocks with wooden pendulum rods vary considerably in their rates of going, at different seasonstof the year ; but the cause of this irregula- rity still remains in some obscurity, for want of a greater number of observations.
Mr. Ludlam says, " That such a pendulum rather loses in cold and gains in warmer weather*." Mr. Wollaston had a clock with a pendulum rod of deal, and he says, " It ap- pears as if the clock gained in warm and lost in cooler weather : but this is not clear. It began to gain before the weather grew warm. Whether this be owing to damp, or any other causes, longer experience and abler observers may discover f."
My clock, of the rate of which the following table contains a short abstract from 1798 to 1807, has a deal pendulum rod, a dead escapement, and goes when winding up. The daily rate was ascertained by a transit instrument which stands in the same room with the clock, and the observations were taken at all convenient opportunities, as an exact rate cannot be found from observations taken only once in a fort- night or three weeks.
It appears from this table, that pendulums with wooden rods gain most in the driest, and lose most in the dampest weather. I could never discover that heat or cold had any effect upon my clock, further than that it went very regularly during hard frosty weather, which I suppose was owing to the moisture in the pendulum being frozen. And it also ap- pears, that moisture does not affect the wood so much ai
* Ludlam's Observatioas, p. 40. + Phil. Trans, abridged, No. 50, p. 216.
the
On Deal Pendulum Rods, 31
the contrary*extreme, but the greatest rate of gaining was only of short duration : hence it may be supposed, that the wood imbibed moisture rapidly as soon a9 the dry season, was over. I am, sir, your humble servant,
Ez. Walker,
Table of (he greatest Variations in the daily Rates of thres Clocks with Deal Pendulum Rods,
Greatest varia- Greatest an-
Time of the year when the greatest los^ and gain in the daily rate of the clock took place.
1798. 1799- 1800. I SOI.
1802. 1803.
1804. 1S06.
1806. 1807.
1770 1771
1767. 1768.
Feb. Sep. Feb. July Feb.
4th and the
14th
24 th
25th
4th
l<
23
Aug. 18th Jan. 7th July lMh March 7 th Oct. 11th Feb. 1 8th ijSep. 25 th
6th, 15th, 25th, 26th,
5th, «7th,
8th, 14th,
9th, 13th, 23d, 29th,
ion in the daily •ate of the lock in twelve nonths.
nual varia- ion, in the ate of the
clock.
+
-f
+
+
73" \ 10 /
} I
59 \ 51 /
} }
4S 16 33
48
4-83"
3*67
6-4
6-1
5-64
5-81
Another pend, with a ivoffden rod put to the same clock.
Between Jan. 24 tb and the 25th,
Do. June 20th 22d,
Do. Dec. 27 & Jan. 1, 1807, Do. Auo-. 7th and the 9th,
5-39
4*22
The Rev, Francis Wollaston's Clock*. Between Dec. 22d and the 30thj— 1-9 Do. June 1st 18th1 + 2-4
}|
From Lvdlam's Observations, p. 44
Between Oct. 30th &Nov. 13th, Do. May 1 8th and the 3 1 st
— 2-2 + 3*2
}
4*3
54
* Philosophical Transactions abridged, No. 50, p. 21$.
VI. An
[ 32 ]
VI. An Account of a Method of hastening the Maturation of Grapes, .% John Williams, Esq., 'in a Letter to the Rt. Hon. Sir Joseph Banks, Bart. K.B. P.R.S.*
SIR,
At is a fact well known to gardeners, that vines, when ex- posed in this climate to the open air, although trained to walls with southern aspects, and having every advantage of judicious culture, yet in the ordinary course of our seasons ripen their fruit with difficulty. This remark, however, though true in general, admits of some exceptions ; for I have occasionally seen trees of the common white muskadlne , and Hack cluster grapes, that have matured their fruit very well, and earlier by a fortnight or three weeks than others *>f the same kinds, and apparently possessing similar advan- tages of soil and aspect.
The vines that ripened the fruit thus early, I have gene- rally remarked, were old trees having trunks eight or ten feet high, before their bearing branches commenced. It occurred to me, that this disposition to ripen early, might be occasioned by the dryness and rigidity of the vessels of the old trunk obstructing the circulation of that portion of the sap which is supposed to descend from the leaf. And to prove whether or not my conjectures were correct, I made incisions through the bark on the trunks of several vines growing in my garden, removing a circle of bark from each, and thus leaving the naked alburnum above an inch in width completely exposed ; this was done in the months of June and July. The following autumn the fruit growing on these trees came to great perfection, having ripened from a fortnight to three weeks earlier than usual: but in the succeeding spring the vines did not shoot with their ac- customed vigour, and I found that I had injured them by exposing the alburnum unnecessarily.
Last summer these experiments were repeated ; at the end of July and beginning of August, I took annular excisions 9f bark from the trunks of several of my vines, and that the.
* From Transactions of the Horticultural Society, vol. i.
exposed.
A Method of hastening the Maturation of Grapes, 33
exposed alburnum might be again covered with new bark by the end of autumn, the removed circles were made rather less than a quarter of an inch in width. Two vines of the white Frontiniac, in similar states of growth, being trained near to each other on a south wall, were selected for trial ; one of these was experimented on (if I may use the term), the other was left in its natural state, to form a standard of comparison. When the circle of bark had been removed about a fortnight, the berries on the experimented tree be- gan evidently to swell faster than those on the other, and by the beginning of September showed indications of ap- proaching ripeness, while the fruit of the unexperimented tree continued green and small. In the beginning of Octo- ber, the fruit on the tree that had the bark removed from it was quite ripe, the other only just began to show a dispo- sition to ripen, for the bunches were shortly afterwards de- stroyed by the autumnal frosts. In every case in which, circles of bark were removed, I invariably found that the fruit not only ripened earlier, but the "berries were consi- derably larger than usual, and more highly flavoured.
The effects thus produced, I can account for only, by adopting Mr. Knight's theory of the downward circulation of the sap, the truth of which these experiments, in my opinion, tend strongly to confirm. I therefore imagine by cutting through the cortex and liber without wounding the alburnum, that the descent of that portion of the sap which has undergone preparation in the leaf is obstructed and con- fined in the branches situated above the incision ; conse- quently the fruit is better nourished and its maturation hast- ened. It is certainly a considerable point gained in the cul- ture of the vine, to be able to bring the fruit to perfection, by a process so simple, and so easily performed. But lest there should be any misconception in the foregoing state- ment, I will briefly describe the exact method to be follow- ed by any person who may be desirous of trying this mode of ripening grapes. The best time for performing the ope- ration on vines growing in the open air, is towards the end of July, or beginning of August ± and it is a material point,
Vol. 33. No. 129. Jan. 1809. C not
31 A Method of hastening the Maturation of Grapes,
not to let the reniovvd circle of bark be too wide : from one to i wo eighths of an inch will be a space of sufficient width ; the exnoscd alburnum will then be covered again with new bark hi' fore the folk) wing winter, so that there will be no danger of injuring the future health of the tree.
It is not of much consequence in what part of the tree the incision is made, but in case the trunk is very large, I should then recommend, that the circles be made in the smaller branches.
It is to be observed that all shoots which come out from the root of the vine, or from the front of the trunk situated below the incision, must be removed as often as they appear, unless bearing wood is particularly wanted to fill up the lower part of the wall, in which case one or two shoots may be left.
Vines growing in forcing houses are equally improved in point of size and flavour, as well as made to ripen earlier by taking away circles of bark : the time for doing this, is when the fruit is se|f and the berries- are about the size of small shot. The removed circles may here be made wider than ^on vines growing in the open air, as the bark is sooner re- newed in forcing houses, owing to the warmth and moisture in those places. Half an inch will not be too great a width to take off in a circle from a vigorous growing vine, but I do not recommend the operation to be performed at all in weak trees. _
I tlunk that this practice may.be extended to other fruits, so as to l}«\sj.e.n their maturity,, especially^.?, in which there is a most abundant flow of, 'returning sap; and it demon- strates to us,; why old trees are more disposed to bear fruit than young ones. Miller informs us, that the vineyards in Italy are thought, to improve every year by age, till they arc 50 years old. It therefore appears: to me, that nature, in the course of time, produces effects similar to what I have above recommended to be done by art. For, as trees be- come old,., tfy.e returning vessels do not convey the sap into the roots, ;with the, same -facility they did when young: thus, Jly removing circles of bark, we only anticipate
the
On a new Method of training Fruit Trees. 35
the process of nature ; in both eases a stagnation of the true sap is obtained in the fruiting branches, and the redundant nutriment then passes into the fruit.
I have sometimes found that after the circle of bark has been removed, a small portion of the inner bark has adhered to the alburnum : it is of the utmost importance to remove this, though ever so small, otherwise in a very short space of time, the communication is again established with the root, and little or no effect produced. Therefore in about ten days after the first operation has been performed, 1 generally look at the part from whence? the bark was re- moved, and separate any small portion, which, may have escaped the knife the first time.
T am, sir, yoqr obedient servant,
Pltmaston, Worcestershire, JOHN WlLLlAMS.
April 20, 1803.
, ■ 1 — ,.
VII. On a new Method of training Fruit Trees.; -By Thos. Andrew Knight, Esq.> F.R.S., &cY*-
Jb rom the result of experiments I have made to ascertain the influence of gravitation on the descending sap of trees, and the cause of the descent of the radicle, and ascent of the expanding plumule of germinating seeds f, T have been induced to believe that none of the forms, in which fruit trees are generally trained, are those best calculated to pro- mote an equal distribution of the circulating fluids ; by which alone permanent health and vigour, and power to aflbrd a succession of abundant crops, can be given. I have therefore been led to try a method of training which is, I believe, different from any mat has been practised; and as the success of this method has fully answered every expec- tation I had formed, I have thought a concise account of it might not be unacceptable™ the Horticultural Society. I confine my account to the peach tree, though, with a little variation, the method of training and pruning, that I re-
* From Transactions of the Horticultural Society, vol. i. f PhilosophicalTramactvons, 1806 and 1807.
C 2 commend,*
36 Ow anew Method of trailing Fruit Trees,
commend, is applicable, even with superior advantages, to the cherry, plum, and pear tree; and I must observe, that when trees are by any means deprived of the motion, which their branches naturally receive from winds, the forms in which they are trained, operate more powerfully on their per* manent health and vigour, than is generally imagined.
My peach trees, which were plants of one year old only, were headed down, as usual, early in the spring, and two shoots only were trained from each stem in opposite direc- tions, and in lan elevation of about five degrees ; and when rhe two shoots did not grow with equal luxuriance; I de- pressed the strongest, or gave a greater elevation to the weakest, by which means both were made to acquire and to preserve an equal degree of vigour. These shoots, receiving . the. whole sap of the plants, grew with much luxuriance, and in the course of the summer each attained about the length of four feet. Many lateral shoots were of course emit- ted from the young luxuriant branches; but these were p'nehed off at the first or second leaf; and were in the suc- ceeding winter wholly destroyed ; when the plants, after being pruned, appeared as represented in Plate II. Fig. 1 ► This form, I shall here observe, miyht with much ad van* tage be given to trees whilst in the nursery ; and perhaps it is the only form which can be given, without subsequent injury to the tree : it is also a form that can be given, with very little trouble or expense to the nurseryman.
In the succeeding seascln as many branches were suffered to spring from each plant as could be trained conveniently, without shading each other; and by selecting the strongest zndearlicst buds towards the points of the year old branches, and the weakest and latest near their bases, I was enabled to give to each annual shoot Nearly an equal degree of vi- gour; and the plants appeared in the autumn of the second year nearly as represented in Fig- 2. The experienced gar- dener will here observe, that I exposed a greater surface of leaf to the light, without placing a|iy of the leaves so as to' shade others, than can probably be) done in any other mode of training ? and in consequence of this arrangement, the growth of the trees was bo great, 'that at two years old some * of
On a new Method of training Fruit Trees. 3*1
of them were fifteen feet wide; and the young wood in every part acquired the most perfect maturity. In the win- ter, the. shoots of the last season were alternately shortened, and left their whole length, and they were then prepared to afford a most abundant and regular blossom in the succeed- ing spring.
In the autumn of the third year the trees were nearly as represented in Fig. 3, the central part of each being formed of very fine bearing wood ; and the size and general health of the trees afford evidence of a more regular distribution of the sap, than I have witnessed in any other mode of training.
In the preceding method of treating peach trees very little use was made of the knife during winter ; and I must re- mark that the necessity of winter pruning should generally be avoided as much as possible ; for by laying in a much " larger quantity of wood in the summer and autumn than can be wanted in the succeeding year, the gardener gams no. oiher advantage than that of having a w great choice of fine bearing wood to fill his walls/' and I do not see any ad- vantage in his having much more than he wants ; on the contrary, the health of the tree always suffers by too much use of the knife through successive seasons.
To enier into the detail of pruning, in the manner in which I think it might be done with most advantage, would of necessity lead me much beyond the intended limits of my present communication; but I shall take this opportunity of offering a few observations on the proper treatment of luxu- riant shoots of the peach tree, the origin and office of which, as well as the right mode of pruning them, are not at all ' understood either by the writers on gardening of this coun- try, or the Continent.
I have shown in the Philosophical Transactions of 1805, that the alburnum or sip wood of oak trees loses a consi- derable part of its weight during the period in which its leaves are formed in the spring ; and that any portion of the alburnum affords less extractive matter after the leaves have been formed than previously. I have also shown that the aqueous fluid which ascends in the spring in the birch and C 3 - sycamore
58 On a new Method of training Fruit Trees.
sycamore becomes specifically heavier as it ascends towards the buds ; which, I think, affords sufficient evidence that the alburnum of trees becomes during winter a reservoir of the sap or blood of the tree, as the bulb of the hyacinth, tulip, and the tuber of the potatoe, certainly do of the sap or biood of those plants. Now a wall-tree, from the advantageous position of its leaves relative to the light, probably generates much more sap, comparatively with the number of its buds, than a standard tree of the same size ; and when it attempts to employ its reserved sap in the spring, the gardener is compelled to destroy (and frequently does so too soon and too abruptly) a very large portion of the small succulent shoots emitted, and the aphis too often prevents the growth of those which remain. The sap in consequence stagnates, and appears often to choke the passages through the small branches ; which in consequence become incurably un- healthy, and stunted in their growth : and nature then finds means of employing the accumulated sap, which, if retained, would generate the morbid exudation, gum, in the produc- tion of luxuriant shoots. These shoots, our gardeners, from Langley to Forsyth, have directed to be shortened in sum- mer, or cut out in the succeeding spring ; but I have found great advantages in leaving them wholly unshortened ; when they have uniformly produced the finest possible bearing wood for the succeeding year ; and so far is this practice from having a tendency to render naked the lower or in- ternal parts of the tree, whence those branches spring, that the strongest shoots they afford invariably issue from the buds near their bases. I have also found that the laterals that spring from these luxuriant shoots, if stopped at the first leaf, often afford very strong blossoms and fine fruit in the succeeding season. Whenever therefore space can be found to train in a luxuriant shoot, I think it should rarely or never be either cut out, or shortened : it should, how^ ever, never be trained perpendicularly, where that can be avoided,
VIII. Pm<
[ 39 ]
VIII. Proposed Improvement of the Hygrometer, By J. Berzelius*.
Ualton's admirable researches have at last decided the dispute respecting the water of the atmosphere, which had lasted for nearly a whole century. The least absurd of the ideas advanced on the subject was, that the water became dissolved by the air, much in the manner as other solid bo- dies are dissolved by water, and that the aqueous meteors depended on alterations in the solvent capacity of -the air, whereby the water is sometimes precipitated, producing clouds and rain, and at times dissolved, producing exhalations. But Dalton has proved, that the water of the atmosphere is independent of the air; and that if the earth were deprived of the latter, it would nevertheless be surrounded by aqueous vapour, the extent of which would depend upon the degree of heat only ; its increase in an increase of temperature being rather hindered than promoted by the air. The water con- tained in the air is in a gasiform state, mixed with the at- mospheric air, just as in this the oxygen is mixed with the nitrogen, or as water is mixed with any other fluid. The quantity of water-gas in the air (as we have said) is in pro- portion to the temperature*; and if the latter were immu- table, the former would also continue the same ; but per- petual changes of sitifations, circumstances, and tempera- ture, produce continual alterations in this gas of the air, and from this alone are most of the aqueous meteors derived. Dalton, by a series of experiments, has calculated the, quan- tity of water capable of maintaining a gasiform state, cor- respondent with every degree of the thermometer ; and in a separate, table determined these quantities according to the different columns of mercury they support. For instance, at _ i5°f it is equivalent to a column of 0-064 inches, at — 5° to 0-120, at OMo 0-183, at + 15° to 0*422, at + 50° to 2*90, and at the boiling point to 25-0 inches, and this in vacuo as well as in the open air. But it seldom happens
* Translated from Berzclius's Philosophical Journal, 1808. f What Thermometer does M. Berzelius use ? Edit.
C 4 that
40 Proposed Improvement of the Hygrometer.
that the air is charged with water to the maximum of its temperature — a circumstance which renders the indications of the hygrometer highly useful and necessary. The hy- grometer should express— To what column of mercury the water-gas of the air corresponds ? and at the same time de- termine the absolute quantity of the gas ; and, the tempe- rature of the air being known — How much of this gas it can take up beyond what it already holds, and how soon t,he exhalation thereof can take place? Our usual hygro- meters of hair, and of whalebone, are, in this respect, very imperfect : the results from them are not much to be relied on, having always a relation to the temperature in which the examination is made. v
Dalton made use of a very plain instrument for his hy- grometrical essays : he filled a long cylindrical glass vessel with cold well water, and when the dew appeared to coat the outside, he decanted the water, and wiped the glass well with linen, after which he returned the water, and this he repeated until the glass ceased to appear moist upon the in- troduction of the water ; when he, by means of the ther- mometer, examined the temperature of the water so pour- ed in : he then found the degree of heat at which the air might prove saturated (if I might so say) with the contained water-gas, and in consulting his tables he learned what co- lumn of mercury coincided therewith, he being already ac- quainted with the temperature of the air. This simple ap- paratus served all his purposes.
We nevertheless may easily see, that although this me- thod is built upon a true principle, yet it will prove to be both inconvenient, tedious, and defective, as the precise temperature at which the glass should cease to appear moist cannot possibly be attained. Therefore, to obtain a greater certainty in the result, though scarcely with less trouble, I altered Dalton's plan in the following manner :
Let us suppose that the air which we are about to exa- mine is at 20°, and that a glass of ordinary spring water, generally at 7° when recently taken from the spring, is be- dewed in this air. The difference between the temperature of the air and the water is then equal to 13°. Should we take
12 glass
Proposed Improvement of the Hygrometer. 41
1 2 glass vessels, in the first of which we mix 12 parts of this spring water with one part of water which has acquired the temperature of the air; in the second, 1 1 parts of the former with two of the latter, and so in a decreasing ratio through- out, we then obtain fluids which differ from each other by one degree of temperature. Of these we examine the first which does not bedew, and its temperature then precisely indicates the expansive capacity of the water-gas of the air. Should the air happen to be too dry, so as not to yield a deposition of water, then we might render it cooler by the addition of sal ammoniac which dissolves in it ; and in winter we can increase the cold by snow, with salt or sal ammoniac. But even this method is slow and troublesome for hygro- metrical investigations. I therefore determined to precipi- tate the water from the air by the thermometer itself, as follows :
The bulb, defended by a case of oiled silk, being immersed in the cold water, was taken up after having acquired the temperature of the water. It then became covered with va- pour of water; I observed also the degree of the thermometer when the dew disappeared, and found the expansive capa- city of the water-gas, according to Dalton's tables, tolerably near. But I also found that a very damp air at -f 18° to -f- 20° produced a somewhat greater result than what it ought to be, because the thermometer, when much water is deposited on its bulb, proceeds little beyond the true point before all is evaporated. Besides, there is another circum- stance which renders the use of the ordinary thermometer less certain, that, namely, a small portion of deposit is not accurately distinguished on the bulb. I therefore caused a thermometer bulb of steel to be made, greatly oblongated, its outside highly polished, and thereto attached a steel tube an inch long, wherein I closely cemented a thermo- meter tube, and made thereof an actual thermometer. This instrument completely answered my purpose. When the bulb with its oil case was immersed in the cooling mixture, and taken up as the mercury fell an inch, or every other inch according to circumstances, I at last arrived at a pe- riod when the bulb became covered with a quickly-passing
coat
42 Materials for a History of the Prussiates.
coat of aqueous vapour, and the scale then expressed the degree of expansive capacity of the water-gas of the air with the greatest precision possible. This kind of hygrometer, besides the nicety of its results, also has the advantage that an experiment may be made without loss of time and trouble, and does not lire the observator like the former methods.
JX. Materials for a History of the Prussiates, By Af. Proust*.
Part Second. Some Precipitations by the simple Prussiate.
J- ins prussiate yields, with metallic solutions, results dif- ferent from those of the triple prussiate. Scheele had already remarked some of them, and the following came under my observation :
Silver. Triple prussiate : a white precipitate which soon became blue, on account of the white prussiate of iron which is mixed with that of silver.
Silver. Simple prussiate : a white curd which does not change.
Gold. Triple prussiate : nothing.
Gold. Simple : white precipitate, which becomes of a fine yellow.
If we heat the mixture, this precipitate, when heated, does not fulminate ; it is a true prussiate of gold. When heated in a retort, it gives water, abundance of empyreu- matic oil, carbonic acid gas, which burns with a blue flame, and a residue of gold mixed with chareoal powder. Upon looking over my notes I do not find ammonia mentioned, perhaps from neglect.
Molybdic Acid and Oxide of Tungsten. — The two prus- siates yielded nothing in either of these cases.
Titanium. Triple prussiate : Prussian blue proceeding from the iron always retained by this oxide.
• From Annates de Chimie, tome Ix. p. 225. — For M, Proust's first paper, H t the preceding volume.
Titanium*
Materials for a History of the Prussiales. 43
Titanium. Simple ditto: yellow oxide of iron, such as the prussiate gives with the solution* of red oxide. I have never yet been able to obtain titanium exempt from iron.
Uranium. Triple prussiate : precipitate of a blood colour.
Uranium. Simple: whitish yellow. v
Cobalt. Triple prussiate : precipitate of a grass green.
Cobalt. Simple : clear cinnamon colour.
Nickel. Triple prussiate : greenish white precipitate.
Nickel. Simple : yellowish white.
Manganese. Triple prussiate : precipitate of a pea-bloom colour.
Manganese. Simple : dirty yellow.
Copper. Triple prussiate : a fine crimson.
Copper. Simple : yellow.
White muriate of copper, or muriate the oxide of which is at the minimum dissolved in muriatic acid. — Triple prus- siate: white precipitate, red inclined to crimson. We find that if this muriate was perfectly exempt from oxide at the maximum, the precipitate would be white. The solution of this muriate is like that of iron ; it is difficult to keep it at the zero of hyper-oxidation, on account of the air.
The same muriate : simple prussiate : curdled precipitate, perfectly white. Some drops of potass take the prussic acid from it, and restore the yellow colour to it, which is the colour of the oxide of copper at the minimum*
Platina and the two prussiales : nothing.
Prussiate of Mercury .• — This is obtained, as we already know, by treating the red oxide of mercury with Prussian blue. This salt crystallizes easily in tetrahedral prisms.
It is always opaque. It may contain potash, as we shall see presently, if there was any in the Prussian blue. It also contains oxide of iron ; we may perceive this from the fol- lowing experiment :
Heat some grains with muriatic acid in a small matrass, and white prussiate is precipitated.
In order to purge it from iron, we must boil its solution over red oxide several times : at every boiling it deposits oxide of iron ; but this depuration is very tedious.
The prussiate of mercury changes its state on passing over
the
44 Materials for a History of the Prussiutes.
the red oxide, and seems to take .a surcharge of it : for it does not any longer crystallize in prisms, but in small groups of very fine needle-like crystals. Their solutions also require more concentration : new solutions do not re- store them to their first form.
This salt heated in a retort is very easily decomposed, and indeed totally, if we be not too hasty in heating it. It is sufficient to heat some grains of it in a tube three or four lines in diameter closed at one end. If, while it is heated, we present the open end to the flame, the prussic gas mixed with gaseous oxide takes fife. Its flame is red and blue, terminated by a vellowish aureola. One hundred grains of prismatic prussiate distilled yielded 72 grains of mercury, and on another occasion 72-£.
The residue, being from eight to nine grains, was a mix- ture of charcoal and carbonate of potash. This is not sur- prising; the alkali cannot (it-compose the prussiate of mer- cury : it certainly belongs to the Prussian blue, which was that used in commerce.
The products from this distillation are ammonia and oil in abundance, besides a mixture of carbonic acid gas and carbonic acid.
There was apparently no prussiate with a base of oxide at the i7iinimiim ; for the prussic acid, applied to mild mer- cury, and to the nitrate with a minimum, base, eliminates a portion of mercury, and gives prussiate with a base of red oxide, the same as that obtained by treating this acid di- rectly with red oxide.
The red oxide also decomposes the simple prussiate. Po- tass is also separated from it ; and as it has no action upon the prussiate of mercury, the latter crystallizes in the mass. It also completely decomposes the triple prussiate, which requires long ebullitions : in this case the black oxide, the clement of this salt, passes to the state of red oxide, and is deposited in ochre. A part of the mercury gives up to it the oxygen which it requires for this : hence it hap- pens that we find it native with the ochre which is precipi- tated ; but without the hyper-oxidation of the iron, which, as we know, diminishes the affinities of this metal, the ox- ide /
Materials for a History of the Prussiates. ^ 45
ide of mercury would not succeed perhaps in decomposing a combination so strong as that of the triple prussiate.
Diluted sulphuric acid has no action upon the prussiate of mercury even with heat, and not the slightest smell of prussic gas is perceived.
Potass saturates the sulphuric acid as the excipient of the prussiate, but precipitates nothing.
Concentrated sulphuric acid destroys the prussic acid, gives sulphureous acid, and thereby puts an end to every mean of comparison.
The nitric acid is not more successful, even after ebul- lition. We perceive very early a little nitrous gas, but it is certainly the black oxide containing the prismatic prussiate which occasions it : to conclude, the prussiate crystallizes in the mass of the acid. The alkalis saturate this last, and also precipitate nothing from it.
It does not elude the muriatic acid in the same way, how- ever. There is a separation of prussic gas, a complete de- composition, and the prussiate is totally changed into corro- sive sublimate. Alcohol also dissolves entirely the saline residue of this operation : finally, examined by the reagents, we find no longer any sublimate. Alcohol, as we know already, does not dissolve the prussiate of mercury.
Potash dissolves in abundance the prussiate of mercury by means of heat. This salt crystallizes in it upon cooling. Alcohol separates it from it, and we recover it entirely.
The muriate of tin at the minimum, and hydro-sulphu- retted water instantly decompose this prussiate, and the prussic acid becomes free.
We have seen that the muriatic acid acted efficaciously upon this prussiate. From this it should seem that the sal ammoniac which presents to the prussic acid a principle ca- pable of uniting with it, should be able to exchange the oiher with the mercury : this does not happen, however. If we heat a solution of mercurial prussiate, and of muriate of ammonia, there is nothing new. Alcohol separates them entirelv. Potash and limewater precipitate nothing from them ; not an atom of corrosive sublimate; and the green Sulphate, which could uot fail to form prussiate of iron
with
46 Materials for a History of the Prussiates.
with that of ammonia, were the latter present, does not undergo the least change.
Prussic Gas. — Twenty drachms of triple prussiate heated in a.retort with a sufficient quantity of weak sulphuric acid, charged four ounces of alcohol with about twenty -four grains. I kept flic alcohol in a bell glass over the bath of mercury: the gas is dissolved rapidly, but it would have taken much more. The water of the intermediate receiver was also surcharged with it : the smell was pungent and suffocating, and its taste very strong of almond kernel. This water did not disturb barytcs. The gas always tends to se- parate from it, and continually elevates the stopper : if we plunge a small matrass of it into hot water, it is rapidly se- parated, and burns at the opening of it : if we bring the flame of a candle to it, \\e perceive smoke; doubtless because a part of the carbon escapes, as in the combustion of the vo- latile oils.
The prussic acid dissolved in water and well corked is de- composed by itself. It is coloured yellow in four or five months. It loses its smell gradually, becomes turbid, and deposits a sediment of a coffee colour, which, after having been heated, presents all the characters of carbon.
It gives by distillation a little water, with prussic and ammoniacal acid. The carbon is azotized ; and it has resumed one of the principles which the acid abandons by its destruction ; for I have heated it with carbonate of pot- ash, and it gave me a lixivium proper for making Prussian blue.
But while the carbon is separated by retaining azote, the greatest part of this last, added to the hydrogen, is consti- tuted in ammonia : we also find it in the yellow liquor, with the rest of the acid which has escaped its destruction.
The prussic gas, dissolved in water, does not disturb the solution of green sulphate: but when it has passed through the changes we are about to mention, it disturbs it and gives a blue, because the ammonia of new formation concurs to it. Lastly, this liquor when distilled gives prussiate of am- monia, and there is no longer any thing in it but atoms of a charry matter which are deposited. It would have been
important
Materials J or a History of the Prussiates. 47
important to have ascertained if the carbonic acid existed there with ammonia, but I neglected it at the time. I shall, however, return to that subject.
Prussic alcohol is preserved extremely well : we might even conclude from this, with some foundation, that if al- cohol is more proper than water for its solution and preser- vation, the prussic gas, considered besides in its qualities of being aromatic and inflammable, is perhaps more visibly allied to oily combustible products, and of a complex na- ture, than to saline substances.
It results from these facts, in the first piace, that there is only one prussiate of mercury, being that of which the base is at the maximum. Secondly, that all this exaltation of affi- nities which the prussic acid borrows from the black oxide, when it is requisite to use potash, or the red oxide. of iron, and upon which Berthollet has insisted with so much jus- tice, ceases to be necessary to it, if it is in contact with oxides of gold, silver, copper, cobalt, nickel, uranium, mercury, &c. We see, in fact, that with regard to the lat- ter, this acid, the affinities of which are so indolent, and so little deserve the title of affinities, has however no oc- • casion for black oxide, in order to furnish with mercury a saline combination, very soluble, very crystallizable, en- dowed, in a word, with all the characters which distinguish the most perfect compounds. Add to these mysterious cir- cumstances, its preference to mercury over all the alkalis, and its not yielding its oxide either to the nitric acid or to the sulphuric acid, which their power raises so much above it; and lastly, its only yielding 4o the muriatic acid, which we know to be in so many respects inferior to the sulphuric and nitric acids.
Lixivium of Animal Charcoal. -^Equal parts of charcoal of blood, and of carbonate of potash, made red-hot in a covered crucible, have always furnished me with the richest lixivium.
Thinking that the carbonic acid might be an obstacle, to the saturation of the potash, I added lime to the mixture, but the lixivium was not improved by it.
I kept red-hot for half an hour, a mixture of 144 grains
cf
4ft Materials for a History of the P r us slates.
of charcoal, and the same quantity of carbonate. The lix- ivium hem? finished, the charcoal extracted was only 104 grains : 40 grains were destroyed.
Thc.'e 104 grains were again treated with 144 of carbonate: they were reduced to 62 ; loss 42.
The lixivium of these two experiments was saturated with the solution of the sulphate of iron used in commerce : the blue of the first, after the colour was struck, was double in volume to that of the second.
In order to ascertain the influence of temperature, I tried three mixtures of equal quantities. The first was kept red- hot for half an hour, the second one hour, and the third an hour and a quarter. The first lixivium gave very little blue; the two last gave a great deal, and much about the same quantity. These results prove either that the simple prus- siate, being that which predominates in the lixiviums, is preserved in the midst of the carbonaceous alkaline mass, or that it is reproduced in proportion as it is destroyed.
Tue charcoal of blood, pulverized, liquefies in the air : when washed, it gives sea salt, and carbonate of soda hold- ing a little prussic acid in solution.
The charcoal of blood, when treated in this way a second time, still yields blue, but in small quantity ; a third, less sensibly; a fourth, not at all. This charcoal, when made red-hot, is incinerated with much facility without exhaling the ammoniacal smell. It appears, that in proportion as it loses the azote, it becomes more combustible, and resem- bles more closely vegetable charcoals : the nitric acid, how- ever, does not inflame it. The azote being susceptible of forming concrete combinations capable of resisting a high temperature, what would be the influence of animal char- coal in the formation of steel ?
Equal parts of charcoal of blood, washed, and of pot- ash rendered caustic by lime, yielded, by the distillation of the simple prussiate of ammonia, plenty of gas, which had the same smell with the prussic, and which burns red. - Equal parts of this same charcoal, and of oxide of manga- nese, yielded carbonate and prussiate of ammonia. ■ The desire of forming ammonia to some profit, led me to
the
Materials for a History of the Prussiates. 49
the following experiment : I distilled the following mix- ture i charcoal of blood, six drachms; argil and sea salt, each two drachms; but the produce in sal ammoniac was much below my expectations.
All the vegetable charcoals azotized are proper for making Prussian blue. Thus those of gluten, of chick peas, indigo, and of pit-coal, have yielded dyeing lixiviums, sometimes mixed with hydro-sulphuret : those of sugar-cane and of milk do not give any indication of blue.
Charcoal of chesnuts and of ^rush-wood, which are preferred at the foundcries to any other kind, because they have the advantage of being extinguished the moment the bellows cease, do not owe this to a2ote, for their Irxiviums do not contain any thing prussic in them.
Cream of tartar made red-hot gives a lixivium, which does not give the least blue : nor did two parts of cream of tartar and one of sal ammoniac ; but one part of sal am- moniac with four of cream of tartar yield a lixivium which contains simple prussiate. It gives blue with the green sul- phate of commerce. Cream of tartar and nitre of soda, nothing.
This result proves clearly that it is by the azote alone that animal are preferable to vegetable charcoals. It also results from this, that if we can at any time discover some azotized combination, more capable of supporting a strong heat than the ammoniacal salts, we might succeed in forming the prussic acid in a manner perhaps less laborious than by ihe animal charcoals.
Examination of the Lixiviums. — By distillation they give continually prussic acid and ammonia: we have seen the origin of this a little higher.
They contain carbonate of potash in a great quantity.
Simple prussiate of potash.
Triple ditto.
Sulphate of potash.
Phosphate of lime.
Sulphur.
They deposit phosphate of lime in proportion as we eva- porate them : I know not how it is formed,
Vol. 33. No. 129. Jan. 1809* D If
SO Materials for a History of the Vrussiales.
If we saturate a portion of lixivium with sulphate of iron, and examine the blue liquor formed by it, we discover phos- phate of iron. This phosphate induced Westrumb to think- that the prussic acid was phosphoric.
Alcohol applied to concentrated lixiviums takes simple prussiate from them ; but it appears difficult to purify them by this means. The triple prussiate remains in the lixivium with the carbonate.
Of these two prussiates, one only can give Prussian blue with solutions of red oxide ; namely, the triple prussiate, be- cause it is provided with black oxide. The other cannot, because it has not the black oxide: but it does so, and becomes triple prussiate, as soon as we mix the lixiviums with the sulphate of iron of commerce: and consequently, if we use sulphate completely red, we shall have infinitely less Prussian blue, because, the black oxide being wanting, it could not become triple prussiate and give blue with this sulphate. Two experiments will render this apparent.
I divided a lixivium into two equal parts; one part was precipitated with red sulphate, and the other with the green sulphate of commerce. The excess of oxides being separated, the blue of the second was in proportion to that of the first as four to one.
The first lixivium, when filtered, exhaled a strong smell of almonds. I saturated it with potash, in order to fix once more the free prussic acid : when tried afterwards with red sulphate, it did not give one atom of blue; but with the green sulphate it gave abundance. We may therefore con- clude that, without the aid of black oxide, a carbonaceous lixivium would not give with solution of red oxide the whole of the blue which it might. From this would arise the Joss that might be suffered of all the simple prussiate contained in a lixivium if we only used a sulphate the oxide of which was completely red •> and from this proceeded the mistake into which 1 fell when I advised it. I did not reflect that, if the green sulphate has the inconvenience of giving pale prus- siate, the oxygen of the air soon remedies this defect ; but it has the essential advantage of furnishing to the simple prussiate the portion of black oxide which it requires in
order
Materials for a History of the Prussiates. 51
order to convert it into a triple salt, and may afterwards furnish blue with the red solutions. In this way practice had preceded theory in accomplishing an object; but practice also becomes in its turn a rational formula, from the moment that it is confirmed by theory. Two other experiments strengthen this demonstration.
The lixiviums are generally precipitated with a solution of four parts of alum, and one of the sulphate of commerce.
I divided one of these solutions into two parts : the one was hyper-oxidated by the oxy-muriatic acid, and the other not. I afterwards saturated them with carbonaceous lixi- vium. The common solution furnished blue in abundance, but the hyper-oxidated gave a very pale precipitate, which was only a little blue mixed with a great deal of alumine. This experiment does not differ essentially from the pre- ceding. It has only the advantage of showing that the alum is but a passive ingredient in the formation of Prussian blue.
It is not the same therefore with the lixiviums of the ma- nufacturer, as it is with an alkali passed over Prussian blue: the latter will always give blue in abundance, because it comes out of the operation tripled, but the lixiviums do not-. They could not give it but in proportion to the triple prus- siate which they contain : it is in order to increase it, or to raise their simple prussiate to the same degree, that it is in- dispensable to use, if not a sulphate rigorously green, at least one which contains a certain quantity of green ; and this is preciselv the usual quality of that of commerce, how- ever old it may be.
These details also explain to us, that if the lixiviums contain a portion only of tripled prussiate, it is because charcoal of blood has not iron enough to furnish for rais- ing all the simple prussiate formed during calcination to the triple degree, or rather because a part of the latter again becomes simple prussiate by the loss of its oxide, is we have seen happen to it when heated alone. Of these two opinions, however, I adhere to the last, because I have remarked, that the charcoal which served the lixiviums gives ashes which always contain much iron : thus, in the calcination of the alkaline- carbonaceous mixtures, we cannot presume with
D 2 reason,
52 Materials for a History of the Prussiates,
reason, that it is iron which is wanting in the prussiate; and even if we reflect on it, it is astonishing to see that the triple prussiate, which certainly exists in the lixiviums, could defend its oxide against the effects of the charcoal, which tends to reduce it continually. In short, all this part of the subject is very obscure. We do not know the period at which the prussic acid is formed, if it be destroyed in order to be reproduced, nor finally the degree of heat to be applied to the boilers, in order to obtain the greatest possible quantity of the one or the other of the prussiates which it is the object of the manufacturer to obtain.
The existence of the triple prussiate is clearly demon- strated in the lixiviums, by the following experiment :
Saturate a lixivium with dilute sulphuric acid : carbonic acid is first set free, afterwards comes prussic acid from the free prussiate : but it must be afterwards heated : we then obtain the triple prussiate, and the white prussiate of iron i» set free. Besides this, the old concentrated lixiviums de- posit octahedral crystals of triple prussiate.
The prussic lixivium has two distinct tastes ; the one of potash, and the other of kernels : and from this latter taste we judge of its quality. If it perfumes the mouth but feebly it is not good; and either the mixture has not been sufficient- ly heated, or the charcoal has been used too sparingly. I think also, that the calcination of the mixtures in the open air ought not to contribute to the augmentation of the prus- siates, and that it would perhaps be more advantageous, and less troublesome, to heat them in close crucibles placed in a reverberating furnace, since it is in other respects certain that agitation is by no means necessary to the success of this operation.
When we have occasion to concentrate the lixiviums, in order to diminish their volume, or in order to preserve them, we should begin before every thing, as observed by Cura- dcau, in placing the simple prussiate beyond the reach of destruction : this may be at once effected by pouring green aulphate into it by small portions at a time. The green sul- phate is completely dissolved ; the lixivium at first becomes red, and then yellow : an excess of sulphate does not alter
it
Materials for a History of the Prussiates* 53
it at all, because the potash which predominates reduces it to oxide. The latter is then deposited without passing to the state of prussiate. To attain this, it must be accom- panied by an acid, for the oxide in question (being only at the minimum) has no effect upon the triple prussiate. The following experiment clearly demonstrates the advantages of this method :
I divided a lixivium into two equal parts: the one was prepared or tripled by green sulphate, the other not. I af- terwards distilled them : the former gave no suspicion of the presence of ammonia, and the latter furnished it as usual. It is indispensable, therefore, to prepare lixiviums be- fore concentrating them. Lastly, neither the red oxide, nor its sulphate, as Scheele experienced, can be dissolved in the simple prussiate, and give it the quality of triple prussiate : this oxide, although fit to become the base of Prussian blue, cannot decompose the triple prussiate : it must necessarily be used when dissolved in an acid.
Recapitulation,
The pru6sic acid is composed of carbon, azote, and hy- drogen, in proportions with which we are not yet acquaint- ed. Considering the great Quantity of charcoal, however, which it leaves after its destruction in several eases, we mav conjecture that it contains carbon in a greater proportion than the two other substances. No person has supposed that oxygen entered into its composition ; and in truth the well-known affinities of its three elements, added to the cir- cumstances attending its formation, have not as yet per- mitted us to hazard the opinion.
The prussic acid, when by itself, has very few of the general qualities of the acids. It has not a sour taste : it does not redden turnsole : it is not so easily dissolved in water (the true solvent of the acids) as it is in alcohol : in this last solvent it is decomposed even spontaneously, and without the assistance of the external air. It forms with the alkali* combinations so imperfect, that we find in them, almost in a state of perfect separation, the specific proper- ties of the component parts, and the carbonic acid, the
D 3 weakest
5% Materials for a History of the Prussiates*
V akest of all, is sufficient to decompose them. In a word, its combustibility, taste, aromatic smell, its being gene- rated in the m; st of volatile oils, and its preservation in alcc.hol, exhibit qualities which much more strongly re- semble oily and inflammable productions than saline sub- stances.
The prussic acid, notwithstanding its trifling saline energy, has a powerful action on the major oxide of mer- cury : it furnishes with this oxide a saline combination, so well characterized in its attributes, that we are compelled to acknowledge that it acts in certain circumstances like the most powerful acid. Nothing in fact is wanting to the prus- siate of mercury, to entitle it to be ranked among the most perfect of metallic salts : it will perhaps astonish some che- mists, to see that it refuses to be united to the minor oxide; but by a concurrence of affinities, of which we have other examples, it raises it to the state of major oxide, by elimi- nating a part of the metal, in order to form, with the other, prussiate of mercury.
The prussic acid has no action upon the red oxide of iron ; but it attacks the black oxide, and produces white prussiate with it. This prussiate, it is true, is not absolutely white, the difficulty of preparing, with green sulphate, a pre- cipitate at the zero of hvper-oxidation, not permitting it : thus, it is always greenish ; but as, upon drying, it becomes perfect Prussian blue, we cannot doubt that the prussic acid, plus the base of the green sulphate, will give, all perturba- tion being out of the question, a prussiate equally white with that which we obtain by more easy means.
Prussian blue is not a simple combination, as has been thought. The following observation will sufficiently prove this assertion : We know, for instance, that the basis of this blue is red oxide : but if this oxide be sufficient of itself for Making Prussian blue, why should not the prussic acid and the red oxide furnish it? Why should not the solutions of this rxide, and the simple alkaline prussiates, giveitalso? T re must necessarily be another element in Prussian blue: the f /.lowing facts clearly demonstrate this : When we apply potash to Prussian blue we obtain a yellow crystal-
lizablc
Materials for a History of the Prussiates, "55
Jizable salt, which has always a constant proportion of black oxide.
If we employ the yellow prussiate in reproducing Prussian blue, this oxide re-enters with the prussic acid into the new combination. The black oxide is therefore an element ne- cessary to the formation both of the crystallizable prussiate and of the Prussian blue, and likewise of all the metallic prussiates prepared with the triple prussiate of potash.
There are metals which are susceptible of forming simple and triple prussiates, such as copper, silver, manganese, cobalt, nickel, uranium, &c. There are some which give simple prussiate, such as gold, mercury, &c. There are some also which give triple prussiate only, such as iron, &c. Lastly, some of them do not appear susceptible either of the one or the other. But, with the exception of Prussian blue and prussiate of mercury, all the rest arc little known, and merit examination. The black oxide united to the prussic acid may pass from the one combination to the other without- changing its state : the base of this combination may even be raised from the minimum to the maximum, without the black oxide on that account taking any part in this change. The combination of the acid with this oxide is maintained by so powerful an affinity that the aikalinehydro-sulphurets cannot separate them, or rather they cannot touch the oxide in the triple prussiate of potash, or in Prussian blue.
The prussic acid united to this portion of black oxide, which enables it to form triple, alkaline, or metallic prus- siates, is a peculiar combination, the existence of which is not doubtful ; but with which we are not as yet acquainted, except in these prussiates alone.
The triple prussiate of potash cannot undergo a red heat without losing the black oxide, and consequently without being reduced to the state of simple prussiate.
The simple prussiate is also decomposed, but by a far lower temperature : its acid is destroyed, and reduced to am- monia and carbonic acid : it is the destruction of this salt by the heat of ebullition, which degrades the lixiviums for preparing Prussian blue. >
The simple prussiate assumes the character of triple prus-
D 4 siate,
56 Observations of a Comet.
siate, as soon as we present to it either the black oxide, or a salt with a base of black oxide, and acquires, besides the advantage of crystallizing, that of being no longer decom- posable by the heat of ebullition.
This prussiate, which was the test liquor so long wanted by chemists, does not give Prussian blue with solutions of red oxide; but it gives them if ihey contain black oxide, be- cause its acid is attached immediately to that portion of the same oxide, which ought to serve as an intermedium be- tween it and the red oxide.
The triple prussiate of iron, or Prussian blue, strongly heated, is reduced to ammonia, to the two gases of carbonic acid and gaseous oxide, to iron (feracerc) and to charcoal.
The prussiate of mercurv gives the same products by its decomposition, besides a certain portion of oil.
The charry lixiv'mms contain but little triple prussiate, and a great deal of simple prussiate. They must not be con- centrated without having in the first place strengthened the constitution of the simple prussiate by an addition' of black qxide, or of green sulphate.
In order to obtain from these lixiviums the whole of the Prussian blue which they are susceptible of giving, it is in- dispensably requisite to use a sulphate, a portion of which at least is green : without this precaution, the simple prussiate contained in them could not furnish blue with a sulphate, the base of which was completely red.
To conclude, if this memoir be compared with that of Scheele, it will be found that all the facts above stated were perfectly well known to him : but they appeared to me to require some further elucidation ; and with this view I lay rny present memoir before the public.
X. Observations of a Comet, made with a View to investi- gate its Magnitude i and the Nature of its Illumination , By William Hekschel, LL.D. F.R.S*
X he comet, which We have lately observed, was pointed out to me by Mr. Piggot, who discovered it at Bath the
* From Philosophical Transactions for 1308, Part H.
2Sth
Ohservat ions of a Comet . 5 7
28th of September; and the first time T had an opportunity of examining it was the 4th of October, when its brightness to the naked eye gave me great hopes to find it of a different construction from many I have seen before, in which no solid body could be discovered with any of my telescopes.
In the following observations, my attention has been di- rected to such phaenomena only, as were likely to give us some information relating to the physical condition of the comet: it will therefore not be expected that I should give an account of its motion, which I was well assured would be most accurately ascertained at the Royal Observatory at Greenwich.
The different parts of a comet have been generally ex- pressed by terms lhat may be liable to misapprehension, such as the head, the tail, the coma, and the nucleus ; for in reading what some authors say of the head, when they speak of the size of the comet, it is evident that they take it for what is often called the nucleus. The truth is, that inferior telescopes, which cannot show the real nucleus, will give a certain magnitude of the comet, which may be called its head ; it includes all the very bright surrounding light ; nor is the name of the head badly applied, if we keep it to this meaning ; and since, with proper restriction, the terms which have been used may be retained, I shall give a short account of my observations of the comet, as they re- late to the above-mentioned particulars, namely, the nucleus, the head, the coma, and the tail, without regarding the or- der of the time when they were made. The date of each observation, however, will be added, that any person who may hereafter be in possession of more accurate elements of the comet's orbit, than those which I have at present, may repeat the calculations in order to obtain a more accurate
result.
Of the Nucleus.
From what has already been said, it will easily be under- Stood, that, by the nucleus of the comet, I mean that part of the head which appears to be a condensed or solid body, and in which none of the very bright coma is included. It should be remarked, that from this definition it follows, that
when
58 Observations of a Comci.
when the nucleus is-very small, no telescope, but what has light and power in an eminent degree, will show it di- stinctly.
Observations.
Oct. 4, 1807 . IO-feet reflector. The comet has a nu- cleus, the disk of which is plainly to be seen.
Oct. 6. I examined the disk of the comet wit-h a proper 6et of diaphragms, such as described in a former paper*, iu order to see whether any part of it were spurious; but when the exterior light was excluded, so far from appearing larger, as would have been the case with a spurious disk, it appeared rather diminished for want of light; nor was its diameter lessened when I used only the outside rays of the mirror. The visible disk of the comet therefore is a real one.
Oct. 4. I viewed the comet with different magnifying powers, but found that its light was not sufficiently intense to bear very high ones. As far as 200 and 300, my 10-feet reflector acted very well, but with 400 and 500 there was nothing gained, because the exertion of a power depending on the quantity of light was obstructed f, which I found was here of greater consequence than the increase of mag- nitude.
Illumination of the Nucleus.
Oct. 4, 6h. \o. The nucleus is apparently round, and equally bright all over its disk. I attended particularly to its roundness.
Oct. 18. The nucleus is not only round, but also every where of equal brightness.
Oct. 19, I see the nucleus again, perfectly round, well defined, and equally luminous. Its brilliant colour in my ten-feet telescope is a little tinged with red ; but less so than that of Arcturus to the naked eye.
Magnitude of the Nucleus, Oct. 20. In order to see the nucleus as small as it really Isj we should look at it a long while, that the eye may gra-
* See Phil. Trans, for 1805, p. 53. Use of :he Criterion, f See Phil Tram, kn 1800, p. 78.
dually
Observations of a* Comet. 5#
dually lose the impression of the bright coma which sur- rounds it. This impression will diminish gradually ; and when the eye has got the better of it, the nucleus will then be seen most distinctly, and of a determined magnitude.
Oct. 4. With a ia ven-i'eet reflector I estimated the dia- meter of the nucleus of the Comet at first to be about five Seconds ; but earni after I called it four, and by looking at it Ion c-r, t supposed it could uot exceed, three seconds.
Oct. 6. W I •.; -ctor, power 221. The apparent disk of the comet is much less than that of the Georgian planet, which being an object I have seen so often with the same in- strument, and magnifying power, this estimation from me- mory cannot be very erroneous.
Oct. 5. Micrometers for measuring very small diameters, when high magnifying powers cannot be used, being very little to be depended upon, I erected a s?t of sealing-wax globules upon a post at 2422 inches from the object mirror of my ten-feet reflector, and viewed them with an eye glass, which gives the instrument a power of 221, this being the same which I had found last night to show the nucleus of the comet well. I kept them in their place all the day, and reviewed them from time to time, that their magnitudes might be more precisely remembered in the evening, when I intended to compare the appearance of the nucleus with them.
On examining the comet, I found the diameter of its nu- cleus to be certainly less than the largest of my globules, which, being '0166 of an inch, subtended an angle of 3"*97 at the distance of the telescope in the day time.
Comparing the nucleus also with the impressions which the view of the second and third had left in my memory, and of which the real diameters were '0325 and -0290 of an inch, and magnitudes at the station of the mirror 2"* 77 and 2"*4 7, I found, that the comet was almost as large as the second, and a little larger than the third.
Oct. 18. The nucleus is less than the globule which sub- tends 2-7 7.
Oct. 19. The air being uncommonly clear, I saw the co-» met 40 mmutes after five ; and being now at a considerable
altitude^
60 Ohservations of a Comet.
altitude, I examined it with 289, and having but very lately reviewed my globules, T judged its diameter to be not only less than my second globule, but also less than the third : that is, less than 2"'4 7.
Oct. 6. The 20-feet reflector, notwithstanding its great light, does not show the nucleus of the comet larger than the ten-feet, with an equal magnifier, makes it.
Oct. 28. My large ten-feet telescope, with the mirror of 24 inches in diameter, dots not increase the size of the nu- cleus.
Oct. 6. Being fullv aware of the objections that may be made against the method of comparing the magnitude of the nucleus of the comet with objects that cannot be seen together, I had recourse to the satellites of Jupiter for a more decisive result, and with my seven-feet telescope, power 202, I viewed the disk of the third satellite and of the nucleus of the comet alternately. They were both already too low to be seen very distinctly ; the diameter of the nucleus however appeared to be less than twice that of the satellite.
Oct. 18. With the ten-feet reflector, and the power 221, a similar estimation was made ; but the light of the moon would not permit a fair comparison.
Oct. 19. I had prepared a new ten-feet mirror, the deli- cate polish of my former one having suffered a little from being exposed to damp air in nocturnal observations. This new one being uncommonly distinct, and the air also re- markably clear, I turned the telescope from the comet to Jupiter's third satellite, and saw its diameter very distinctly larger than the nucleus of the comet, i turned the telescope again to the comet, and as soon as I saw it distinctly round and well defined, I was assured that its diameter was less than that of the satellite.
6h. 20'. I repeated these alternate observations, and al- ways found the same result. The night is beautifully clear, and the moon has not yet risen to interfere with the light of the comet.
Nov. $0. With a seven-feet reflector, and power only 75, I can also see the nucleus; it is extremely small, being little more than a mere point.
Of
Observations of a Comet, 61
Of the Head of the Comet.
Whfen the comet is viewed with an inferior telescope, or if the magnifying power, with a pretty good one, is either much too low, or much too high, the very bright rays im- mediately contiguous to the nucleus will seem to belong to it, and form what may be called the head.
Oct. 19. T examined the head of the comet with an indif- ferent telescope, in the manner [ have described, and found it apparently of the size of the planet Jupiter, when it is viewed with the same telescope and magnifying power.
With a good telescope, I saw in the centre of the head a very small well-defined round point.
Nov. CO. The head of the comet is now less brilliant than it has been.
Of the Coma of the Comet.
The coma is the nebulous appearance surrounding the head.
Oct. 19. By the field of view of my reflector, f estimate the coma of the comet to be about six minutes in diameter.
Dec. 6. The extent of the coma, with a mirror of 24 inches diameter, is now about 4' 45".
Of the Tail of the Comet. Oct. 18. 7h. With a night glass, which has a field of view of nearly 5°, I estimated the length of the tail to be 3°-*-; but twilight is still very strong, which may prevent my see- ing the whole of it.
Nov. 20. The tail of the comet is still of a considerable length, certainly not less than 2f degrees.
Oct. 26. The tail of the comet is considerably longer on the south-preceding, than on the north-following side.
Tt is not bifid, as I have seen the comet of 1769 delineated bv a gentleman who had carefully observed it*.
Oct. 28. 7-feet reflector. The south-preceding side of the tail in all its length, except towards the end, is very well defined ; but the north-following side is every where hazy
* Dr. Lind of Windsor.
and
65 Observations of a Comet.
and irregular, especially towards the end ; it is also shorter than the south -preceding one.
The shape of the unequal length of the sides of the tail, when attentively viewed, is visible in a night glass, and even to the naked eye.
Oct. 31. 10-feet reflector. The tail continues to be better defined on the south -preceding than on the north-follow- ing side.
Dec. 6. The length of the tail is now reduced to about 23' of a degree.
Of the Density of the Coma and Tail of the Comet.
Many authors have said, that the tails of comets arc of so rare a texture, as not to affect the light of the smallest stars that are seen through them. Unwilling to take any thing upon trust, that may be brought to the test of observation, I took notice of many small stars, that were occasionally covered by the coma and the tail, and the result is as follows.
Oct. 26. 6h. l.i'. Large 10-feet reflector, 24 inches aper- ture. A small star within the coma is equally faint with two other stars that are on the north-following side of the comet, but without the coma.
7h. 30'. The coma being partly removed from the star, it is now brighter than it was before.
Oct. 31. 6h. 5'. 10- feet reflector. A star in the tail of the comet, which we will call a, is much less bright than two others, b and c, without the tail.
Two other stars, d and e, towards the south of h and r, are in the following skirts of the tail, and are extremely faint.
7h. 20'. The star e is now considerably bright, the tail having left it, while d, which is rather more involved than it was before, is hardly to be seen.
7h. 50'. The star a, toward which the comet moves, is involved in denser nebulosity than before, and is grown fainter.
d is involved in brighter nebulosity than before, but being near the margin, it will soon emerge.
' Sh.
Observations of a Comet. 63
Sh. 35.'. Being still more involved, the star a is now hardly visible.
e is quite clear of the tail, and is a considerable star ; d re- mains involved.
9h. 10'. The star d is also emerged, but the comet is now too low to estimate the brightness of stars properly.
Nov. 25. 7h. 35'. There is a star a within the light of the tail, near the head of the comet, equal to a star b situate without the tail, but near enough to be seen in the field of view with a. The path of the head of the comet leads to- wards a, and a more intense brightness will come upon it.
8h. 46'. The start/ is now involved in the brightness near the head of the comet, and is no longer visible, except- now and then very faintly, by occasional imperfect glimpses; but the star b retains its former light. ,
Nebulous Appearance of the Comet. Dec. 6. The head of the comet, viewed with a mirror of 24 inches diameter, resembles now one of those nebulae, which in my catalogues would have been described, " a very large, brilliant, round nebula, suddenly .much brighter in the middle. "
Dec. 16. 7 -feet reflector. The night being fine, and the moon not risen, the comet resembles " a very bright, large, irregular, round nebula, very gradually much brighter in the middle, with a faint nebulosity on the south- preceding side."
Jan. 1, 1808. 7-feet. " Very bright, very large, very gra- dually much brighter in the middle."
If I had not known this to be a comet, I should have ad- ded to my description of ii as a nebula, that the centre of it might consist of very small stars ; but this being impossible, I directed my ten-feet telescope with* a high power to the comet, in order to ascertain the cause of this appearance; in consequence of which I perceived several small stars shining through the nebulosity of the coma.
Jan. 11. 7-feet. "Bright, pretty large, irregular round, brighter in the middle. "
Feb. 2. 10-feet, 24-inch aperture. ff Very bright, larg<*,
irregulaF
64 Observations of a Comet.
irregular round, very gradually much brighter in the mid- dle." There is a very faint diffused nebulosity on the north- preceding side; I take it to be the vanishing remains of the comet's tail.
Feb. 19. Considerably bright; about |th of the field = &' 26' ** in diameter, gradually brighter in the middle. " The faint nebulosity in the place where the tail used to be, still projects a little further from the centre than in other directions.
1 Feb. 21 . Less bright than on the 19th : nearly of the same size : gradually brighter in the middle. The nebulosity still a little projecting on the side where the tail used to be.
Result of the foregoing Observations, From the observations which are now before us, we may draw some inferences, which will be of considerable im- portance with regard to the information they give us, not only of the size of the comet, but also of the nature of its illumination.
A visible, round, and well defined disk, shining in every part of it with equal brightness, elucidates two material cir- cumstances ; for since the nucleus of this comet, like the body of a planet, appeared in the shape of a disk, which was experimentally found to be a real one, we have good reason to believe that it consists of some condensed or solid body, the magnitude of which may be ascertained by calculation. For instance, we have seen, that its apparent diameter, the 19th of October, <5h. 20', was not quite so large as that of the third satellite of Jupiter. In order therefore to have some idea of the real magnitude of our comet, we may ad- mit that its diameter at the time of observation was about 1", which certainly cannot be far from truth. The diameter of the third satellite of Jupiter, however, is known to have a permanent disk, such as may at any convenient time be measured with all the accuracy that can be used ; and when the result of such a measure has given us the diameter of this satellite, it may by calculation be brought to the di- stance from the Earth at which, in my observation, it was compared with the diameter of the comet, and thus more
accuracy,
Observations of a Cornel. 65
iabctiracy, if it should be required, may be obtained. The following result of my calculation, however, appears to me quite sufficient for the purpose of general information. From the perihelion distance 0 64 7<191> and the rest of the given elements of the comet, we find, that its distance from the ascending node on its orbit at the time of observation was 73° 45' 44"; and having also the Earth's distance from the same node, and the inclination of the comet's orbit, we compute by these data the angle at the sun. Then by cal- culating in the next place the radius vector of the comet, aud having likewise the distance of the Earth from the sun, we find by computation, that the distance of the comet from the Earth at the time of observation was 1 • 1 69 1 92, the mean distance of the Earth being 1. Now since the disk of the comet was observed to subtend an angle of 1", which brought to the mean distance of the Earth gives i'*l 69, and since we also know that the Earth's diameter, which, according to Mr. Dalby, is 7913-2 miles*, subtends at the same di- stance an angle of 17"*2, we deduce from these principles the real diameter of the comet, which is 53S miles.
Having thus investigated the magnitude of our comet, we* may in the next place also apply calculation to its illumina- tion. The observations relating to the light of the comet - were made from the 4th of October to the lyth. In all which time the comet uniformly preserved the appearance of a planetary disk fully enlightened by the sun : it was every where equally bright, round, and well defined on its borders* Now as that part of the disk which was then visible to us could not possibly have a full illumination from -the sun, I have calculated the phases of the comet for the 4th and for the 19th ; the result of which is, that on the 4th the illumi- ' nation was 119° 45' 9", as represented in Plate II. fig. 4, and that on the 19th it had gradually increased to 124° 22' 40", of which a representation is given in fig. 5. Both phases appear to me sufficiently defalcated, to prove that the comet did not shine by light reflected from the sun only; for, had
* Sec Philosophical Transactions for I 791, p. 239. Mr. Dalby gives the two semiaxes of the Earth, from a mean of which the above diameter 79 13-1682 is obtained. s
Vol. 33. No. 129. Jan. 1809, E this
t)6 Observations of a Comet,
this been the case, the deficiency, T think, would have been perceived, notwithstanding the smallness or' the object. Those who are acquainted with my experiments on smalls silver, globules-* will easily admit, that the same telescope which could show the spherical form of balls, that subtend- ed only a few tenths of a second in diameter, would surely not have represented a- cometary disk as circular, if it had! been as deficient as are the figures which give the calculated appearances.
If these remarks are well founded, we are authorised to conclude, that the body of the comet on its- surface is sclf- luminous, from whatever cause this quality may be derived.. The vivacity of the light of the comet also had a much greater resemblance to the radiance of the stars, than to the mild reflection of the spin's beams from, the moon, which i* an additional support of our former inference.
The changes- in the brightness of the small stars, when they are successively immerged in the tail or coma of the comet, or cleared from them, prove evidently, that they are sufficiently dense to obstruct, the free passage of star-light. Indeed if the tail or coma were composed of particles that reflect the light of the sun, to make them visible we ought rather to expect that the number of solid reflecting parti- cles, required for this purpose, would entirely prevent our seeing any stars through them. But the brightness of the head, coma, and tail alone, wilbsufficiently account for the observed changes, if we admit that they shine not by reflec- tion, but by their own radiance; for a faint object projected on a bright ground, or seen through itj will certainly appear somewhat fainter^ although its rays shointf meet with no ob- struction in coming to the eye. Now, as in this case we are sure of ths bright interposition of the parts of the comet,, but have no knowledge of floating particles, we ought cer- tainly not to ascribe an effect to a hypothetical caus^, when the existence of one, quite sufficient to explain the pheno- mena, is evident.
If we admit that the observed full illumination of the disk
* Phi!osoph"-al Transactions for ISOj, p. 58,. the. 5th experiment.
of
Observations of a Comet. 67
of the comet cannot be accounted for from reflection, we may draw the same conclusion, with respect to the bright- ness of the head, coma, and tail, from the following consi- deration. The observation of the 2d of February mentions, that not only the head and coma were still Very bright, but that also the faint remains of the tail were still visible ; but the distance of the comet from the Earth, at the time of observation, was nearly 240 millions of miles*, which proves, I think, that no light reflected from floating parti- cles could possibly have reached the eye, without supposing the number, extent, and density of these particles far greater than what can be admitted.
My last observation of the comet, on the 2 1st of February, gives additional support to what has been said ; for at the time of this observation the comet was almost 2*9 times the mean distance of the sun from the Earth f. It was also nearly 2*7 from the sun J. What chance then could ravs going to the comet from the sun, at such a distance, have to be seen after reflection, by an eye placed at more than 275 millions of miles § from the comet? And yet the in- stant the comet made its appearance in the telescope, it struck the eye as a very conspicuous object.
The immense tails also of some comets lhat have been observed, and even that of the present one^ the tail of which, on the 18th of October, was expanded over a space of more than nine millions of miles ||, may be accounted for more satisfactorily, by admitting them to consist of radiant mat- ter, such as, for instance, the aurora borealis, than when we unnecessarily ascribe their light to a reflection of the sun's illumination thrown upon vapours supposed to arise from the body of the comet.
By the gradual increase of the distance of our comet, we have seen, that it assumed the resemblance of a nebula; and it is certain, that had I met with it in one of my sweeps of the zones of the heavens, as it appeared on either of the
* 239894939.
f The sun's mean distance being 1, that gJ" the comet was 289797.
\ The comet's distance Irom the sun was 2*669100.
§ 27i077Sb«<. || 9160542.
E 2 days
6S On Commerce.
days between tlieGth of December and the. 21st of February, it would have been put down in the list I have given of ne- bulae. This remark cannot but raise a suspicion, that some comets may have actually been seen under a nebulous form, and as such have been recorded in my catalogues ; and were it not a task of many years' labour, I should undertake a re- view of all my nebulae, in order to see whether any of them were wanting, or had changed their place ; which certainly would be an investigation, that might lead to very interest- ing conclusions.
XI. On Commerce, Being a second Communication from M1\ Graham, in Answer to our Correspondent Lapis.
To Mr. Tilloch.
SIR,
Jn my last letter T endeavoured to prove, and illustrate from a variety of articles, that no country could produce all that was necessary for the comfort, health, protection, and se- curity of its inhabitants. I likewise showed, by a reference to very barren and uncomfortable situations, that the inha- bitants of such districts, so far from deserting those coun- tries, were rather more attached to the soil than the people of much more favoured climates. Without further recapi- tulation, I will pass on to another observation of your cor- respondent Mr. Lapis. I will not call it an objection, be- cause he does not give his opinion as positive; but he is apt to think, from the different languages spoken by the different nations of the world, as well as from the natural barriers of kingdoms, such as large rivers, long ridges of almost impassable mountains, and the still' more extended ocean, which rolls its mighty waves between different coun- tries, that the Author of the universe never intended that social intercourse between nations which I seemed to argue, but rather that they should be completely independent of each other. I am much pleased with this observation, not so much on account of giving me an opportunity of com- municating my ideas on the subject, but as I consider it a
matter
On Gqpmerce. <*9
scatter of great importance, as well as useful and curious disquisition. I hope some of your readers, who have more time and far superior abilities, will favour us with a more full illustration of the subject.
Jn order to prevent my being misunderstood, it may bs here necessary to observe that, in all I have written, I wish to keep in view this idea or leading principle, (viz.) That the Supreme Creator of this woriu is the universal parent of all its inhabitants ; that they are all alike his children ; and that all his laws have in themselves a natural tendency to promote the happiness of his creatures. At the same time it is necessary to observe that the benevolent Author of our existence was fully aware of all the weaknesses as well as imperfections of his creatures, and that it was impossible for the whole inhabitants of this earth to be under one go- vernment: he has therefore divided or separated different countries and kingdoms by such barriers as I have already mentioned : yet, notwithstanding these great impediments, and what would appear almost insurmountable difficulties, we find that the ambition of man is not fully restrained ; for some nations are constantly endeavouring to make inroads on their neighbours : now, if this is the case under the pre- sent formation of this world, surely it would have been much more so if nature had not fixed those strong bounda- ries. While on the one hand I admit this argument in its fullest latitude, on the other I can never enough admire the kind benevolence of our Creator, in giving such diversity in the productions of the earth to different countries, as to be a very strong incitement for friendly and social intercourse : even the principle of curiosity, which has so powerful an effect on the human mind, is a great inducement to visit distant countries ; but this can never be done with, cither pleasure orsatisfaction, unless such nations or people have a friendly communication with each other. T must like- wise observe how easily a social intercourse is maintained with all- the different parts of the earth when there is no hostile intention 5 — With what ease and facility can a few merchant-vessels carry the various productions of this coun- ty to another, and bring in exchange many articles of
E 3 which
76 On Commerce.
which we are in want ? But how many difficulties attend the fitting out of an armed fleet ! This requires all the united strength and energies of the nation. Thus, while the Su- preme Being has laid strong restraints on all the more dan- gerous passions of men, he at the same time has placed very powerful incitements in the human mind for sociability, and from the diversified productions of the earth has made it their interest to have a friendly intercourse with one an- other, to behave and act as subjects of one supreme go- vernor, and as the children of one kind and benevolent parent. Were I to call in the aid of the inspired writers, they would appear in full force in favour of my argument; but I only beg leave to recommend a serious perusal of the principles of Christianity to many who assume that name, while their ■whole conduct is diametrically opposite to its precepts, otherwise we should never have heard of that impious and unchristian maxim, Natural Enemies : from the general idea of the Devil such a supposition would be natural, but to im- pute such to our merciful Creator is surely horrid impiety.
J hope it will not for a moment be supposed that I here make any allusion to Mr. Lapis, — -No, not in the least; but that there are such as I describe is but too evident. As I would not willingly overlook any argument or objection brought forward by Mr. Lapis, I will beg leave to observe, that I fully agree with him in the manner in which he has slated the first beginning or principles of commerce, as be- longing to one nation or individual country: but he could not perceive that the same was rendered necessary between different kingdoms. Now I think I have shown in a variety of instances, that there is a greater necessity for an inter- change with different countries than with the distinct parts of the same nation ; and that, in the present system of the imiverse, every law or institution contrary to this order of nature may justly be said to counteract the benevolent dis- pensations of the Creator. The more I consider this sub- ject, the more I am convinced that it is a law or principle which runs through every department of society, from a single individual to that of nations. I am rather surprised that Mr. Lapis should mention (as part of his objection to
- X)n Commerce. 71
my statement) that that man who could excel in the manu- facture of any article in his own country, had more merit than he who imported it from another : — most certainly he 'has; and whoever will turn to my first Essay will find, that .to promote this spirit amongst the inhabitants I state to be one of the principle objects of a wise and patriotic politician or statesman. I think I have already proved to a demon- stration, that there is no country which can produce all that may be said to be of use, comfort, &c, &c, to the inhabi- tants,— I mean as far as the productions of the soil are con- cerned. I likewise contend that no exertions, either by individuals or united bodies, can bring the making or manufactctre of every article to the same degree of perfection to which it is sometimes brought in another country ; at least such a phenomenon has not yet appeared in the world, and,, for the happiness of the human race, I believe it never will. Nations, like individuals, if they possessed within them- selves every requisite which they found necessary or useful., would be too much puffed asp with vain-glory, pride, and ■presumption ; wou4d consider themselves as the only fa- vourites of Heaven, and look down with contempt on all their fellow-mortals as beings of an inferior order, and not alike the children of the same kind and benevolent parent. Nations, as well as individuals, with all their wants, weak- nesses, and imperfections, are but too apt to fall into this dangerous error: — How much more would it be so if every country did, or even could, by its exertions supply all its wants ! Would not such be apt to forget the Creator, and to exclaim, " My own right hand has gotten me the victory?** I am well aware that several foreign articles mav justly be termed luxuries, and that a very improper use is often made .of them ; but if some people will injure their health or hurt their constitution, by excess in that which ought only to be used as a medicine, or for the comfort and support of old age, the blame in all those cases lies with man, who only abuses the bounties of his benevolent Creator. I well know- that rice is more congenial to the support of the inhabitants of those countries where it is the natural produce, than it would be to an Englishman who has been accustomed to
K 4 bread
7 s On Commerce.
bread madofrqni flour*. But, even iti our years of greatest plenty, is not rice a very useful article ? From the gene^ ral reasonableness of the price, even the lower orders of the people find it pleasant, wholesome, and to them a luxuri^ ous treat: only a few years have passed away since all classes of people were happy to find in it a substitute for bread. I am apt to think that the Supreme Governor of the world saw that it was necessary so to constitute the order of nature, that years of scarcity might sometimes occur, to teach ungrateful men the value of his blessings, as well as to show them the necessity of a friendly intercourse with other countries : and I am persuaded that, if that social inter- course for which I contend were more generally adopted, even famine would be divested of half its horrors.
I have already said, that I would neither recommend wine nor foreign brandy, as a common beverage to an English labourer, in preference to good malt liquor; but however preferable this may be while youthful vigour blooms in the countenance, and manly strength braces every nerve : when old age weakens the limbs, bows down the body, and dries up every source of pleasure, Who will deny that a change is often useful, and that even a little wine as well as some other foreign cordial will make glad the heart of man, and occasionally help to cheer the languor of declining years ? If this be a true state of the matter, (and I think it will readily be admitted by every person who has made observations on these things.) was I not justified in saying, and now re- peating, that it is a cruel policy to deprive the great bulk of the people of any article which may be of such eminent use4 and more particularly when nature requires it -most ? I my- self have known several instances where the physician or apothecary have recommended wine: the attending relatives, of the patient answered (while the sympathetic tear startecj from their eyes) (A O sir, we have no money, it is too dear,
* It would be superfluous to enter into the disquisition whether the natural produce of every country being more proper for the inhabitants than any foreign substitute, did not proceed more from long habit than from any po- sitive law or order of nature: for it is a well known fact, that the stomach and constitution of man very soon assimilate to a great variety of food.
we
On Commerce. 73
We cannot afford it." But of this I forbear. I will only beg leave to mention one or two more article^ to show the great difficulty, if not utter impossibility, of -the people, even in the same country, making some things equal in quality or perfection at a very small distance from each other. London - porter is one article: — there is scarcely a town or village of any note in the kingdom, where the making of porter, in imitation of the London, has not been tried. Brewers and malt-makers have been brought from the metropolis at a very great expense, no money has been spared, every ef- fort which human ingenuity could contrive has been ex- erted,— but all in vain j the difference even to a superficial observer is very evident.
I will only mention one more :-r-the making of Cheshire and Glocester cheese, seemingly a very simple and well known operation ; yet I have never seen what could be call- ed a tolerable imitation, and have known great exertions inade by some wealthy farmers, both from a principle of emolument and curiosity ; but I have never known one who succeeded in any tolerable degree*.
I must now beg your indulgence while I offer a few re- marks on the bad policy of high duties. Whether I con- sider the present system as it affects the revenue, the morals, or the health of the people, it has the most dangerous ten- dency : it teenis with evils of the greatest magnitude. I will not here recapitulate the arguments I used in my first Essav, but will add some others.
To remove as far a3 possible every alluring incitement to transgress the laws of the country, to place at a distance " every temptation which might be supposed too strong for the general virtue of the people, 'has always been the care and study of every wise legislator, much more than to make severe laws or to inflict cruel punishments. I am fully persuaded that there is no person who has studied human
* I hope this will not be understood as meaning to damp ardour, or di- •pirit the exertions of those who wish to persevere in improvements: I only gnention the difficulty, without meaning to »et bounds to human ingenuity or persevering exertion*.
nature,
74 On Commerce.,
nature, whether by reading or from his own observations \vl the world, but will admit the wisdom and utility of this maxim.
I cannot here omit mentioning the great penetration and humanity of our ancestors in framing many of our laws.
The law is positive, " Thou shalt not steal •/' but very great' difference is made between the crime of breaking locks and -bars to commit theft, and when cash or other valuables are placed in very open exposed situations ; and for this very plain and humane reason, — the temptation is supposed to be much more strong in the one case than the other. Com- pare, this with our present system of excise laws, which are of a modern date : in these no allowance is made for the weakness of human nature placed under the strongest temp- tations, sometimes of poverty ; at other times the loss of business, by being undersold by some neighbour who is Jess scrupulous as to illicit connexions : — even that invaluable privilege, trial by jury, is denied to the great bulk of the people connected with the excise. I have often contem- plated with astonishment, that the greatest crimes which can disgrace human creatures are suffered to be tried by a jury the nearest to the place where the crime is connected 5 but this is denied to every offender against the excise laws, unless he is able, and will submit to the enormous expense, of having the cause tried in the Court of Exchequer at Lon- don. I could here adduce a great variety of arguments in •support of this proposition. I wish to prove, as well as re- late, some circumstances, the unavoidable consequence of the present system, which would astonish some, and excite feelings of pity in the breast of the most obdurate ; — but i forbear this.
Lest, however, some may think that I plead too much for the weakness of humanity, I will only beg leave to men- tion two cases, which, I think, -are in point. If the good and pious Agur so earnestly prayed against poverty, lest he should put forth his hands to steal, How necessary then to place, as for as possible, temptation from those whose minds are often little fortified- either by piety or morality ] If he
wbe
On Commerce. $5
who well knew the heart of man closed this petition, (<e Lead us not into temptation") with those, which we are commanded to offer up to our Creator, need I use any further arguments ? I must not, however, omit mentioning a well-known fact, which I am afraid is too little attended to hy those who fix such enormous duties to certain articles*, viz. There is not one amongst a thousand who considers what is called illicit *rade any breach either of religion or morality : if they pay the value of the article to those who sell, they think they have fulfilled every moral obligation. I will now mention a few particulars to show how the health of the people is in- jured by the present system of high duties. I agree with Mr. Lapis, (and I believe it is generally admitted,) that malt liquor is the most wholesome and best beverage for the great bulk of the people: But, since the present enormous imposts, where can it be obtained genuine? Far be it from me to im- peach every brewer of illicit practices ; but the public have had sufficient evidence," that, in different instances, various ingredients, and some of a very pernicious nature, besides malt and hops have been made use of. But, supposing no such practices to have been proved, is it not a well known fact, that not only in breweries, but likewise in distilleries, all the arts of chemistry, and the skill of the most eminent in the pro- fession, are called into action ? To produce the colour most likely to please the eye, to obtain the flavour in most gene- ral approbation, to cause the liquor to sparkle in the jilass, raise a fine head or adhere to the sides of the pot, are, with many other objects, constantly exercising the mind of the operator ; and to obtain such on the easiest terms, or at the least expense, his constant aim and study. It is really asto- nishing how easily some of these objects can be produced by artificial means, which ought only to be the effect of the genuine materials from which the .liquor is made. To ob- tain any foreign liquor in a true genuine state is likewise yery difficult and uncertain ; for in this the temptation is
* Taking the first price of tobacco at 5\d. per pound, while the duty it £$. 3d., it is evident that one cargo smuggled, yields a fortune to the adven- turer.
n equally
70 On Commerce,
equally strong. Even allowing that the first importer has strength of mind sufficient against all the allurements of gain, the article goes through so many hands before it reaches general consumption, that all the well known practices of mixing, (particularly when the flavour is strong,) reducing, and again bringing to lull proof, are too often carried to a great extent.
Even wine is well known to be often so much adulterated, that it is a mixture of no person can tell what. When we consider that this is often used as a medicine, how danger- ous and uncertain must the application often be !
Need I recall the attention of your readers to the various means used to adulterate tea before the reduction of the duty ? Ifsfow it is nearly back to its former high price, the very same consequences will naturally follow*, as soon as any of the countries on the continent shall be in a situation to get tea from China so as it "may be smuggled into this country. What with smuggling from abroad, adiflteration at home, the high price lessening the consumption, the diminution of the re- venue must follow. I should now point out some of the bad effects which high duties have on the morals of the people ; but the evils are so numerous, and the consequences so fa- tal to the peace of society as well as individuals, that the subject would require a separate Essay, and I have already intruded too much on your indulgence. Wishing every sue cess to your useful and entertaining Magazine,
I am, sir, yours, &c,
Berwick, JAMES GRAHAM.
Jan. 2, 1800.
* Before the reduction of the duty on ten took place, the revenue arising' from that article had dwindled to a mere trifle, and the same cause will cer- tainly produce the same cfll'ct.
XII. Memoir
t v l
XII. Memoir upon the Vineyards and Wines of Champdgiie in France : Written in answer to certain Queries circulated hj M. Chaptal. By M. Germon, of Epcrnay*.
PRELIMINARIES f.
JL he ancient province of Champagne, now divided into two departments under the names of La Marne andLaHaule- Marne, has been long celebrated as the vineyard of France. There are two kinds of wines which distinguish this di- strict. ; -
White wines : called Riviere de Marne wines. Red wines : called Montague de Rkeims wines. The white wines are produced from vineyards situated in the valleys and upon the sides of the hills in Epernay, Dizy, Avenay, Cramant, Lemesnil, Month'elon, Chouitly, Moussy, &c. : but in consequence of one of these varieties of nature, for which we cannot always account, the estate of Cumicres, in the midst of so many vineyards celebrated for white wines, and under the same exposure, produces red wines only, and of a quality far superior to the above wines. Among all the vineyards on the river Marne, the can- tons of Hautvillers, Mareuil, Cumieres, and Epernay, are the most advantageously situated : they extend along the river Marne, with this distinction, that the quality of the wine falls off in proportion as the vineyard is distant from tbe river : for this reason Hautvillers and Ay ~have always enjoyed a preference over Epernay and Pierry ; and the latter •wr Cramant, Lemesnil, &c, and these last over Mon- thelon, Moussy, &c.
South exposures produce upon the banks of the Marne ex- cellent white wines, but their declivities and posterior parts, which are called the mountains of Rheims, although situated
* Annates de Chimfc, Vol. Ixi. p. 5.
f The numerous facts contained in this Msmoir render it t'rulv valuable: although the author expresses himself in the language of a good practical cultivator, he does not always display the accuracy of* a modern chemist. We have not hitherto met with any rhin^ more comprehensive on the sub- ject ; and it form* the -materials of (VI. Chaptal's projected work, upon U L'Art dtfaire If l-'i/t." Note of the French Editor.
in
78 Memoir on the Vineyards and Wines
in general towards the north, and almost always to the east, also give red wines of a good quality, and of a fine taste and aromatic flavour.
The slope which overhangs Rheims is divided according to the quality of its wines ; hence we have wines of the mountain, of the lower mountain, and of the estate St. Thierry.
The mountain comprehends Verzy, St. Basle, Verznay, Mailly, Taissy, Ludes, Chigny, Rilly, and Villers-Allerand ; and among these vineyards, the most esteemed are Verzy, Verznay, and Mailly. The rest, although very good, are of a different quality.
The vineyard of Bouzy, which terminates the chain or the horizon between south and east, and which, therefore, belongs to the two divisions, ought not to be omitted. It produces excellent, fine, and delicate red wines, which, from its exposure, participate in the good qualities of Verz- nay and the good red wines of La Maine.
The lower mountain comprehends a great quantity of vineyard countries; among which we may distinguish Cha- mery, Ecueil, and Ville Demange : this last place in parti- cular, when the season is good, yields wine which will keep for ten or twelve years.
The lower mountain extends to the banks of the river Aisne. As the wines it produces are of a middling qualitv, it scarcely requires to be particularized.
The district of Saint Thierry has taken its name, with re- spect to its wines and vineyards, from a laroe extent of grounds containing large vineyards, such as Saint Thierry, Trigny, Chenay, Villefranquenx, Douillon, Hermon ville, and produce very agreeable red wines of "a pale colour, very much in request by the dealers.
But the wine properly called Clos Saint Thierry, and coming from the archbishopric of Rheims, is the only wine which unites the rich colour and flavour of Burgundy to the sparkling lightness of Champagne. Clos Saint Thierry hold* the same rank among Champagne wines, that Clos-vougeot does among those of Burgundy.
In the enumeration of the vineyards of the mountain,
some
of Champagne in France. • 79
gome readers may perhaps expect to find Slllery mentioned, once so remarkable for red and white wines : the truth is, that Sillery wine is in a great measure composed of the wines produced in the territories of Vcrznay, Mailly, and Saint Basle, once made, by a particular process, by the marechale d'Estrees, and for this reason long known by the name of Fins de la Marechal'e, At the revolution this estate was di- vided, and sold to different rich proprietors of Rheims : the senator of Valencia, however, the heir tq a great part of this vineyard, neglects no means of restoring Sillery to its former reputation.
Series of questions put by M. Chaptal, with their answers-
I. Which is the most advantageous Exposure for the Vine? The most advantageous exposure for the vine is, without
contradiction, the south and the east; hut it has been ascer- tained that certain advantages of soil and the nature of the plant must also concur : otherwise various districts, such as Damery, Vanteuil, •Retiil, &c, with the same exposure and; elimate, and also watered by the Maine, would enjoy the same celebrity as Cuinieres, Uautvillers, and Ay. It must be confessed tha»t the former districts produce interior kinds- of wine ; but it remains to be decided whether we ought to ascribe this difference to the culture, the plants, or the soil.
II. Are the high Exposures, the middle Elevations, or the-
lower Grounds, Lest adapted for Vineyards ?■ Of all situations, the middle grounds are. most esteemed : the heat being more eoueentraied in them, they are exempt from the variations of the atmosphere which prevail or eminences, and from the humidity and exhalations whic!> issue from the lower regions: the elaboration, of the sap or juice is therefore more complete in the middle grounds.
III. Does an East or West differ much from a Smith Expo- sure, in occasioning a sensible Difference in the Quality of the Wines?
A western exposure is unfavourable to vegetation : it burns and parches Without any advantage, nor does it give
time:
80 Memoir on the Vineyards and Wines
time for the juice to be elaborated, and spread through alt the channels of vegetation, when mists, humidity, or* dew> succeed : it is a certain fact, that there is a difference of one third in the quality and value between vines situated in east and west exposures.
1Y.' Describe the Nature of 'the Ufovtid or Soil which pro- duces the best fVM,
Next to exposure, the nature of the soil and of the ground influences the quality of the wine. It must be admitted^ however, that grounds with a northern exposure produce" wines of a generous and spirituous description; while an* other exposure, perhaps to the south, yields a poor and com*- inon sort of wine. It is therefore to the salts and the juices of the earth, combined with the influence of the atmosphere, that we must ascribe the goodness and qualities of soils, adapted for vineyards.
The most proper soil for v'mes is a sandy granitic carth> neither compact, nor too thick, nor clayey : frequently in the best exposures, we meet with stony soils, which give very strong wines; but warm and dry seasons are requisite in these cases, and a necessary maturity : beneath these stony soils, there are clayey and unctuous parts, and plenty o£ springs, which conduce to the elaboration of the juice.
In .gtmecal throughout Champagne the soils proper for vines rest upon banks of chalk. The vine, indeed, comes up slowly in this kind of soil, but when it has fairly taken root it grows to perfection : the heat of the atmosphere is tem- pered and modified by the coolness of the chalky beds, the moisture of which is constantly sucked up by the vegetative channels of the vine-plant.
CULTIVATION OP THE V/NE.
V. How is the Vine planted P tn November or December, when the season admits of it, the vine is planted by making an oblong hole or furrow, one foot and a half in depth, by two or three feet in length : the plant is introduced into it and covered with earth, slop- ing it in such a way as to uncover only two or three inches
of
of Champagne in France* Si
of the extremity o: the plant, to which a horizontal and erect position is also given. Each hole of this kind is one foot and a half from the one adjoining, and on the same line in vineyards where the soil is rich ; two feet being al- lowed in light soils. An interval of three feet is left between the rows of the plants, and care is taken when a new row is begun : the plants must not be placed perpendicularly, and directly above each other*
• VI. What is the Way in which tfte Shoots are made f
The plants are inserted into turfs, or in longuettes* The longuette is a mere naked twig, which had been left the year preceding, and which is now carefully raised and de* tached, leaving the young roots behind it.
The turf plant, or marcotte, consists in digging up a turf in the marshes, and introducing into it in spring, by means of a hole made in the middle of the turf, the longuette or slip intended to be planted : this shoot with its earthy ap- pendage is then fixed in the ground, sloping it as usual : the root is formed in the course of the year, and with a pruning-knife the longuette is cut close to the top of the shoot, and they are then removed by men, or on the backs of animals, in order to be afterwards planted : this last way is the most expensive, but it is the surest, and advances the vine very fast in respect to vegetation.
One hundred of longuettes or bare slips cost four or five livres, and turf plants cost from 12 to 14 livres.
But as two longuettes are requisite for each hole or fur- row, when they plant in this way there is a trifling saving, although the other method is far preferable.
VII. Is Grafting advantageous f Grafting is not in general use, except in the vines be- longing to the vine-dressers themselves, and in the large plant : these vines when grafted become yellow, and lan- guish. The graft remains for some years exposed to the air, humidity, and to bad management of the labourer, and in short to all the intemperance of the climate.
Vol. 33. No. 129. Jan, isoo. F VIII. How
S3 Memoir on the Vineyards and Wines
VIII. How long does a good Vine Plant last ?
A good vine plant lasts 50 or 60 years, and frequently longer, according to the care which has been taken of it.
A vine plant is deteriorated generally by the bad manage- ment of the vine-dressers with respect to the shoots or slips: if they are not sunk deep enough in the ground, the vine plant becomes overwhelmed with roots, which at last form a solid cake, and absorb all the juices from the ground : the vine being thus incapable of shooting, the evil ought to be instantly remedied.
IX. W hat Kind of Grapes are best adapted for White Wine? Black and white grapes are planted indiscriminately in the
same vineyard : and this is perhaps wrong ; for the term of maturity is not the same with both kinds of grape. The reason assigned for this practice is, that wine made from black grapes alone would be too vinous, and would become muddy {sujet d tacher) in hot seasons ; while wine mack from white grapes would be too soft : the latter kind of grapes would be too soft, as containing more mucilage (muqueux).
X. Is tlw Black Grape preferable to the White?— State the
Cause of tliis Superiority .
There is not much variety in the grapes of Champagne.
The black are generally preferred to the white grapes for several reasons ; Ln the first place, the black grapes resist much belter the rains and frost so common about vintage time. Secondly, because there is more vinosity and fine- ness in the black grape, and it gives more of what is called body to the wine; the white on the contrary is too muci- laginous, renders the wine soft, and exposes it to become yellow, or to thicken.
There are whole cantons, however, such as Chouilly, Cramauit:, Avise, Bisseuil, &c, where there are but very few black grapes, and yet their wine is in high estimation.
XI. Which of the Exposures is most suhjeet to tJie Hoar- frosts of Spring ? The effects of frost are only to be feared at sunrise: the
-■ eastern
of Champagne in France* 83
eastern exposures are consequently most apt to suffer, al- though it has been ascertained that vine plants freeze in every exposure.
Thus, all the preservative methods hitherto indicated, such as fumigations, or poles armed with long branches of foliage capable or' being agitated by the air, are mere reveries of the imagination : they have been employed indeed in small en- closures; but they never preserved a single cluster of grapes, and are incapable of being applied to a large vineyard.
XII. At wfiat Period is the Vine to he pruned P About the end of February or beginning of March, the most essential operation must be performed, namely, that of cutting the plant. When it is very strong, two branches or stumps only are left.
XIII. How many Eyes are left in the Plant P Three eyes upon each branch : when the vine is weak, one branch only is cut off.
XIV. At what Height from the Ground is the Plant pruned P When the plant is young and the rind is not marked with old prunings, the plant is cut at the height of three or four inches : the vine-dressers cut higher, because they frequently cultivate three branches, and leave four eyes.
XV. To what Height is the Vine allowed to rise P Not higher than a foot and a half, — to avoid dilating the sap too much.
XVI. At what Season does the first Operation in the Vine- yards commence P
After having pruned the vine, the first occupation it that of hoeing: this operation consists in digging up the earth around thv plants, so as to uncover their roots for a moment, and detach the earth from them which may have become clotted ; die hoe being always inserted into the earth about a foot from the plant.
At the end of March, or beginning of April, when the thaws have softened the ground, the hoeing commences.
F 2 XVII. What
i
84 Memoir on the Vineyards and Winei
XVII. What is the Period of Planting by Slips or Cultinsg P This kind of planting is performed at the time when the
vine is planted.
XVIII. In what Manner is this Kind of Planting managed? In pruning, the vine dresser reserves, in the barest and
most sterile places, certain slips, upon which he leaves only two or three stalks, according to the strength of the slip: the hole or furrow being made, the slip is gently inclined, by disengaging the roots, and by means of a pair of tongs the stalks are held while placing in the furrow, at from four to six inches distance from each other : the slip being thus fixed at the depth of a foot or thereabout, a hand-basketfull of manure is thrown at the root of the slip ; the hole is then filled up with natural earth in a loose manner, in order to ad- mit of the two or three stalks sending out their shoots with- out being bruised,
XIX. How many Operations are there to le performed le-
tween the Pruning and the Vintage Season ? The primings being over, as the same vines are not pruned every year, and even in those which have been pruned the earth has not been thoroughly stirred, the vines are trimmed at the beginning of May : this trimming is called labourage au bourgeon, and is followed by the tyting up of the vine plants.
XX. Which is the most favourable Moment for Tycing and
Paring the Vine?
While the vine is in flower, it must not be touched : it must be pared when the flower has nearly passed away, and at the height indicated in Art. XV.: it must afterwards be tied in such a way as to envelop the slip, without in- juring the circulation of the air or the growth of the suckers.
Finally ; about the middle of August, in order to clear away the grass from the roots of the plant, and to raise up the grapes which may have fallen to the ground, a third and last trimming takes place.
The following is the routine practised in the vineyards of Champagne :
J. They
cf Champagne in France. 85
1. They are cut in February or March.
2. Hoed in March.
3. Pruned in April and May.
4. Tied or propped up in April and May,
5. First trimming for the shoots.
6. Pare and tie in June.
7. Second trimming in July.
8. Third trimming in August.
XXI. How is it ascertained that the Grape is sufficiently ripe, in order to commence the Labours of the Mintage ?
At the end of September, or later if the season has been backward, — before proceeding to the labours of the vintage, in order to obtain the fruit at the most complete state of ripeness,
The stalk of the grape must be brown and woody ;
The grape pendent ;
The skin or pellicle of the grape tender, and not brittle when chewed ;
When a seed can be easily detached from the juice of the grape : which should in its turn present a vinous and trans- parent appearance, without having any green in it \
When the grape stones are brown, dry, and not glutinous.
OF THE VINTAGE.
XXTI. What Precautions are necessary for managing the Grapes so as not to injure the White Wines P
Many precautions, even of detail, are necessary in making white wine.
These consist in carefully picking the ripest and soundest grapes from all withered or bruised grapes : they are then put into panniers, and covered with cloths to prevent the effects of the sun's rays, and to avoid fermentation.
The panniers thus covered, being put upon the backs of horses, arc conveyed to the press ; into which they are not emptied, however, until afttr sun-set. From twenty to forty panniers full are put under the press at a time : the contents of two panniers produce half a piece of wine : forty pan- niers yield nine or ten pieces of white wine, and each piece contains two hundred bottles.
[To be continued.] ^
F 3 XIII. Mr.
SIR, <e -
[ 86 ]
XIII. Mr. Davy's Theory. To Mr. Tilloch.
1 thank you for your early insertion of my former com- munication, as by that means I was favoured by Mr. Davyfs observations on it in his lecture yesterday.
" It seems that I misunderstood him : it is fit therefore that I should state that T did so. He did not assert (in reference to the experiment of the decomposition of the sulphate of potash) that the sulphuric acid and the potash repelled each other in consequence of being in opposite states of electri- city, but in consequence of being brought into the same state, " I had understood him to say that the decomposition took place in consequence of the natural electricities of* the sulphuric acid and the potash being reversed by means of the Galvanic apparatus ; and I was less disposed to suspect that I was wrong, from observing the following passage in the Bakerian Lecture for 1807, which seemed to me to con- vey the same doctrine : e In the decompositions and changes presented by the effects of electricity, the different bodies naturally possessed of chemical affinities appear incapable of combining, or of remaining in combination, when placed in a state of electricity different from their natural order.' Philo- sophical Transactions, 1 807, p. 33; and as, in the experiment alluded to, both the sulphuric acid and potash seemed to me to be placed in a state of electricity different from their na- tural one, I was by this means confirmed in my mistake.
ff That I did misunderstand him, however, I am amply sa- tisfied by Mr. Davy's declaration, which is moreover shown by the following passage, which, had it occurred to me at the time, would probably have pointed out my error : it refers to the theory of the decomposition of the fixed alkalies, and is as follows : 'The oxygen being naturally possessed of the ne- gative energy, and the basis of the positive, do not remain in combination when either of them is brought into an electri- cal state opposite to its natural one.' Phil. Trans. 1808, p. o, " Hence, therefore, we are to understand, that in the expe- riment of the sulphat of potash to which I have so often re- ferred,
Mr. Davy's Theory. 87
ferred, upon this neutral salt being placed in the Galvanic circle, either the sulphuric acid or the potash, one or the other of them, is brought into an electrical state opposite to its natural one: consequently, into the name s,tate as the body with which it was united: hence a repulsion ensues, and the compound body is decomposed. This is Mr. Davy's expla- nation. / . N •
•* But I would still presume to request that my former proposed explanation may be considered (which is not in the least affected by my having misunderstood Mr. Davy's ex- planation); for the difficulties in the way of the present seem to be, that we must suppose that in the first instance one only of the parts of the compound body is affected by the battery, and has its natural state of electricity reversed ; and that, ultimately, both are affected ; for, the experiment being completed, the acid is found to be positive, and the potash negative.
ce Is there, however, any repulsion in the case ? Should we not rather consider it as a case of chemical decomposition, in which the attraction between the two constituents of the salt is overcome by more powerful affinities ?
I remain your obliged humble servant,
January 8, 1809. AUDITOR.
XIV. Mr. Daw's Theory. To Mr. Tilloch.
London, January 25, 1809. SIR,
X our correspondent 'Auditor/ notwithstanding his pene- tration, has, I think, misunderstood Professor Davy's rea- soning on electrochemical attraction. His remarks on the inconsistency of the theory and its explanation, such as he conceived them to be, must naturally occur to every consi- derate reader.
But if my memory does not deceive me, Mr. Davy stated : <e An acid that is artificially rendered positive will not com-
P 4 bine
88 Royal Society.
bine with an alkali that is naturally positive, and vice versa Hence it is evident that, if* the electrical state of either th : acid or alkali in the neutral salt is chanced, they cm fto longer remain in union, as they instantly exert towards each other a repulsive power proportionable to the inverse em iy of their natural electrical affinity. This principle oi de- composition, which Mr* Davy merely mentioned in the lec- ture referred to by Auditor, was fully explained and illus- trated in a subsequent one.
He showed, by refined applications of his principles, that in the decomposition of a neutra1 salt in solution the order of the arrangement varies. When popper wires, which rea- dily combine with oxygen, and are easily soluble in an acid, are used to transmit ti)e electricity, the positive wire attracts the oxygen and acid, and repels the hydrogen and alkali. But when platina wires are employed, which have but a very slight affinit- for oxygen and acid, the phenomenon is very different. Oxygen and acid, as before, are attracted by the positive pole; but as they are jnpapable of uniting with the platina, they instantly receive by contact its electric state, and exercise a repulsive power towards it : the same effect takes place with the hydrogen and alkali at the negative pole.
If we follow this course of reasoning, it is evident that the gaseous oxygen and hydrogen must diffuse themselves in the atmosphere as they are liberated from their combina- tions, and the acid and potash must find their states of rest at a little distance from the positive and negative poles.. I am, sir, with gre4 respect,
Your hurnble servant,
A.B.
XV. Proceedings of Learned Societies.
ROYAL SOCJETY.
January 12. — The conclusion of Mr. Davy's Bakerian Lecture was read. In this part of his communication Mr. Davy gave an account of the decomposition of the fluoric acid j detailed some curious experiments upon the muriatic
acid j
Royal Society, 89
acid ; and entered into various new views connected with chemical theory.
Potassium burns, as Mr. Davy discovered, in fluoric acid gas, and separates its hosts, which combines with the potash formed, or with the potassium, if this last be in excess; and this compound of the fluoric basis, and the alkali or alka- line basis, produces fluate of potash by combustion, or by the action of water.
Common muriatic acid gas, Mr. Davy has discovered, con- tains at least a third of its weight of water. Mr. D. has not been able to procure it free from water in an uncombined state ; but he has obtained combinations of muriatic acid with phosphorous acid, phosphoric acid, sulphuric acid, and with phosphorus, free from moisture; and these compounds, even when fluid, though constituted by matter supposed to be intensely acid, do not act on litmus paper nor dissolve alkalis, and are non-conductors of electricity ; but a very small quantity of water develops their energies, renders them conductors, and makes them capable of violently acting upon litmus and alkaline bodies. With these compounds of muriatic acid, potassium detonates violently even at com- mon temperatures. The energy of the explosion has hitherto prevented Mr. Davy from examining the results ; but he thinks it probable that the muriatic acid may undergo change or decomposition in the experiment.
In the course of his general inquiries Mr. Davy examined an experiment, (lately published in Mr. Nicholson's Journal) on the production of ammonia, from a pyrophorus moist- ened with water, by Professor Woodhouse; and states that he has found his results Accurate; but that the formation of the volatile alkali depends upon nitrogen absorbed from the atmosphere by the charcoal employed.
Mr. Davy, by exposing the pyrophorus whilst cooling to hydrogen gas, found that no ammonia could then be pro- duced by the affusion of water.
Mr. Davy, from experiments made upon a large scale, confirms his former analysis of potash, as consisting of about 1 4 of oxygen to 86 of metal.
He defends the theory of Lavoisier against the opinions of
some
90 IVemerian Natural History Society.
some of the disciples of this illustrious man, who suppose the metals to be compounds of hydrogen.
Jan. 19 and 26. — A. Marsden, esq., Vice-president, in the chair. Paxt of a long paper, illustrated with several draw- ings by Mr. Troughton, mathematical instrument maker, was read, describing his instruments and methods of gra- duating quadrants, sectious of circles, and other instruments for mathematical and philosophical experiments. Mr. Trough- ton's theoretical method consists in making o\it a table of errors, by which means he corrects the dots made on the graduated circle, previous to the application of his instru- ment for dividing it into 180 degrees. Of this instrument, invented by his brother, and improved by himself, no cor- rect idea can. be given without the drawings, which unfold the whole secret of the author's superior mode of manufac- turing mathematical instruments.
WERNERIAN NATURAL HISTORY SOCIETY.
At the meeting of this Society on the 14th of January, Dr. Thomas Thomson read an interesting description and analysis of a particular variety of copper-glance from North America.
At the same meeting Dr. John Barclay communicated some highly curious observations which he had made on the caudal vertebrae of the Great Sea Snake, (formerly men- tioned) which exhibit in their structure some beautiful pro- visions of Nature, not hitherto observed in the vertebrae of any other animal.
And Mr. Patrick Neill read an ample and interesting ac- count of this new animal, collected from different sources, especially letters of undoubted authority, which he had re- ceived from the Orkneys. He stated, however, that owing to the tempestuous season, the head, fin, sternum, and dorsal vertebrae, promised some weeks ago to the University Museum of Edinburgh, had not yet arrived ; but thaj; he had received a note from Gilbert Meason, esq., (the gen- tleman on whose estate in Stronsa the sea snake was cast,) intimating that they might be expected by the earliest ar- rivals from Orkney. In the mean time, he submitted to the
Society
Earthquake. 01
Society the first sketch of a generic character. The name proposed for this new genus was Hahydrus, (from a\$ the sea, and J^o; a water- snake) ; and as it evidently appeared to be the Soe-Oi'men described above half a century ago, by Pontoppidan, in his Natural History of Norway, it was sug- gested that its specific name should be H. Pontoppidani.
XVI. Intelligence and Miscellaneous Articles.
EARTHQUAKE.
X he following account of a shock of an earthquake felt at Dunning, in Perthshire, on the 18th of January, about two o'clock A- M. is given by Mr. Peter Martin, surgeon, in Dunning. — He was coming home at the time on horseback, when his attention was suddenly attracted by a seemingly subterraneous noise, and' his horse immediately stopping, he- perceived the sound to proceed from the north-west. After continuing the space of half a minute, it became louder and louder, and apparently nearer, when, all on a sudden, the earth gave a perpendicular heave, and with a tremulous wav- ing motion seemed to roll or move in a south-east direction. The noise was greater during the shock than before it, and for some seconds after it was so loud, that it made the cir- cumjacent mountains reeclio with the sound ; after which, in the course of about half a minute, it gradually died away. At this time the atmosphere was calm, dense, and cloudy, and for some hours before and after there was not the least motion in the air. Fahrenheit's thermometer, when examined (about half an hour after the shock), indicated a temperature of 15 degrees below the freezing point of water. The pre- ceding day was calm and cloudy ; thermometer, eight A. M. 14, eight P.M. 13. The morning of the 18th was calm and cloudy, but the day broke up to sunshine ; thermometer, eight A.M. 19, eight P. M. 16. This was a greater shock than that felt at the same place on the 9th of September, about s'.x A. M. several years ago]; and if it had been suc- ceeded by another equally violent, it must have damaged the houses : but fortunately we have heard of no harm being done.
Natural
92 Natural Hist Dry.
Natural History. — At day- break on the 3d of January I8O0, an enormous fish was descried at half cable's length from Ptnrynquay, steering towards the town, and three boats, under the direction of captain Dunn, were manned to attack him : the first he enclosed, as it were in a pond, formed by a circular curve from head to tail, without doing any injury, A man then courageously cut a hole in the dorsal fin, through which he rove a hooked rope. Upon feeling this, the fish attempted to put to sea, hut being diverted by some hard blows on his snout, he sheered towards the Falmouth road. A three-inch rope doubled was then parbuckled round him, which he instantaneously snapped. A hawser from the quay was next applied to him \ when, after dragging a sloop's anchor, tearing up a moorstone post on the quay, and stav- ing a "boat, he was brought into shoal water, and, it being ebb tide, subdued. He was afterwards towed round by three boats, and with the tackle of a sand-barge and the exertions of 20 men and three horses, he was drawn upon the slip of colonel Heame's quay, where he remained a few davs for the amusement of the curious. He measures 31 feet long, 19 feet round, 9\ feet high, f j feet mouth. It proved to be a male of the Squalus genus, being the Squalus maximus, the Basking Shark, or Sun-fish of Pennant. It abounds in the Irish Channel and on the west coast of Scotland. It is generaiiy seen in pairs. Accordingly the mate of this animal was observed in St. Keverne Bay, next day, by the Wal- singham packet. -
Mr. Taylor the Platonist announces, that he has made some very important discoveries in that branch of the mathe^ matics relating to infinitesimals and infinite series. One of these discoveries consists in the ability of ascertaining thu last term of a great variety of infinite series, whether such scries are composed of whole numbers or fractions. Mr. Taylor further announces, as the result of these dis- coveries, that he is able to demonstrate, that all the leading propositions in Dr. Wallis's Arithmetic of Infinites are false ; and that the doctrine of Fluxions is founded on false princi- ples, and, as well as the Arithmetic of Infinites, is a most -^niarkable instance of the possibility of deducing true con- 3 elusions
; Lectures.— Patents. 03
elusions from erroneous principles. Mr. T. is now com- posing a treatise on this subject, which will be published in the course of next year.
LECTURES.
5/. Thomas's and Guy's Hospitals.
The Spring Course of Lectures at these contiguous Hos- pitals will commence as usual the 1st of February, viz.
At St. Thomas's. Anatomy and Operations of Surgery, by Mr. Cline, and Mr. Cooper. — Principles and Practice of Surgery, by Mr. Cooper.
At Guy's. Practice of Medicine, by Dr. Babington and Dr. Curry.— Chemistry, by Dr. Babington, Dr. Marcet, and Mr. Allen. — Experimental Philosophy, by Mr. Allen. — Theory of Medicine, and Materia Medica, by Dr. Curry and Dr. Cholmeley. — Midwifery, and Diseases of Women and Children, by Dr. Haighton. — Physiology, or Laws of the Animal (Economy, by Dr. Haighton. — Occasional Clinical Lectures on Select Medical Cases, by Dr. Babing- ton, Dr. Curry, and Dr. Marcet. — Structure and Diseases of the Teeth, by Mr. Fox.
N. B. These sveral Lectures are so arranged, that no two of them interfere in the hours of attendance ; and the whole is calculated to form a complete Course of Medical and Chirurgical Instructions. Terms and other Particulars may be learnt at the respective hospitals.
Mr. Singer's extensive Course of Lectures on Electricity will commence at the Scientific Institution, 3, Princes- Street, Cavendish-Square, about the middle of February. They comprise a Historical View of the Progress of Elec- trical Discovery, from the earliest period to the present time; and an Exhibition of every interesting Experiment, with their Application to the Solution of Natural Phenomena, and to the Purposes of Philosophical Research : assisted by Original Illustrations on an Apparatus of considerable extent and power.
LIST OF PATENTS FOR NEW INVENTIONS.
To Phineas Andrews, of Haverstock Hill, in the parish «f Hampstead, in the county of Middlesex, gent., for
certain
04 List of Patents for New Inventions*
certain improvements in the construction of a machine for thrashing. of corn, grain, and pulse, and all kinds of seed. October 31.
To Samuel Crackles, of Kingston-upori-Hull, brush-ma- nufacturer, for a method of making brushes from whale- bone, formerly made from bristles. November 3.
To Samuel Brookes, of Bermondsey, tanner, for an in- vention for splitting raw bull, ox, and cow hides, so that each side of the hide so split, may be manufactured for the purposes for which an entire hide has been before used — as follows: the grain side for coach and chaise hides and other purposes, and the flesh side for losh hides, for white leather, for vellum, tor tanning, and for other purposes. Nov. 3.
To John Hartley, John Musgrave, and William Farmery, of Leeds, machine makers, for a machine for preparing roving, slubbing, spinning, twisting, and doubling of cotton, flax, hemp, tow, worsted, silk, or -any other substance, into threads, preparatory to their being manufactured or otherwise used. Nov. S.
To Nicholas Fairies, of South Shields, esq., for a windlass, windlass bitts, and metallic hawse hole chamber, whereby- great manual labour is saved, and a less space of time is necessary in heaviug-to and getting on board ships' anchors, either in moderate weather or in gales of wind. Nov. 15,
To Jonathan Dickson, of Christ- Church, Surrey, steam- engine maker, for improvements in the construction of tuns, coolers, vats, and backs, used by brewers, distillers, and others. Nov. 15.
To Charles Gostling Townley, of Ramsgate, esq., for improvements applicable to musical instruments of different descriptions. Nov. 26.
To Frederick Nolan, of Stratford, near Colchester, in the county of Essex, clerk, for improvements in the construc- tion of flutes, flageolets, hautboys, and other wind instru- ments now in use. Nov. 26.
To Charles Seward, of Lancaster, block-tin manufacturer, for improvements in the construction of lamps. Nov. 26.
To John Schmidt, of Saint Mary Axe, London, watch- maker, for a phantasmagoric chronometer or nocturnal dial,
representing
Patents. — Meteorology. 93
representing or making visible at night, to an enlarged size, the dial of a watch against the wall of a room ; the reflec- tion obtained by a light and optical apparatus being at the same time sufficient to give the room a pleasing illumina- tion. The nocturnal dial may, with little alteration, be con- structed of any watch or time-piece: but to render the whole as simple and useful as possible, he has also invented a me- chanism, or instrument, which is applicable to the above, on account of its peculiar action, which he calls the myste- rious circulator, or chronological equilibrium, requiring only one hand or nonius to show seconds, minutes, and hours : it is particularly useful, and may, if required, with little al- teration, represent an orrery. Dec. 20.
To John Frederick Archbold, of Great Charlotte-Slreet, Blackfriars-Road, for improvements in making brandy ; comprising, first, a new method in making wine as the worts Or must for the making the brandy, and a still applicable to the working off the same, and a new method of rectifying the spirit when worked off. Dec. 20.
To William Steel, of Liverpool, glass- dealer, for an en- tire new machine engine, or instrument for making white salt. Dec. 29.
To William Tompson, of Dent End, near Birmingham, in the county of Warwick, locksmith, for a lock, which acts in a perpeudicular and horizontal direction, with spring and tumblers, one part being at liberty whilst the other is in motion, the bolts of winch lock return into the body thereof when it is unlocked. Dec. 29.
METEOROLOGY.
lire weather during the present month has been the most severe that has been remembered for many years. The fall of snow has been excessive, and the degree of cold very in- tense. In Scotland the weather has been similar. At Edin- burgh on Saturday the 21st of January, at eleven o'clock P. M. a thermometer constructed by Crighton of Glasgow, stood at 17°. On the following morning, at half past eight o'clock, it stood at 12° ) and at eleven at night it was so low as 9°, On the 23d in the morning the temperature was 1 7°.
METEOaO-
$*
Days of the Month.
Meteorology.
METEOROLOGICAL TABt^
Br Mr. Carey, of the Strand^ For January 1809. Thermometer.
s*a
£
O be 0"S6
Height of
the P>a.om
Inches.
BJO c/j S^
Q 8 *
Weather.
Dec,
Jan.
28 *0
30 31
1
2 3
4 5
t>
7
9 10 II
12 13 14 15 16 17 16 U)
20 21
22 23 24 25 26
30< 37 38 40 39
38 9!
30 33 39
44
8 44
41 43
38 38 34 31 28 28 28 21 22
31 32 32 22 33 42 42
35°
38
42
45
37
38
40
32
33
33
46
44
44
43
46
45
40
38
33
29
30
28
26
28
32 34 34 30 35 36 48
36°
37
39
39
3/
38
33
30
32
33
44
42
41
42
37
41
35
37
30
29
27
25
22
31
32 33 33 31 40 37 45
29'52 •50 •40 •50 •58 •57 •42 •35 •65 '65 •50 •15
28*50
29-20 •14 •40 •50 •68 •80 '75
30-05 •01
29*85 •58
•44 •50 ■04 •70
•45 '75
20
0 0 4 4 0 0 5 0 0 5 4 O
o
0 8 8
12 0
16
o
25
27
25
0
0
q 0
4
0
24
0
Rain
Rain
Cloudy
Cloudy
Small Rain
Rain
Cloudy
Snow
Small Rain
Cloudy
Cloudy
Rain
Rain
Rain
Cloudy
Fair
Cloudy
Rain
Fair
Snow
Cloudy
Fair
Cloudy
Cloudy. In the
afternoon there
was a storm of
rain and sleet.
Cloudy
Cloudy
Snow
Fair
Rain
Cloudy:
Stormy
N. B. The Barometer's height is taken at one o'clock
[ 97 ]
XVII. On Barometrical Measurements*,
To Mr. Tilloch, — Sir, JM. De la Place in his Mtckanique Celeste, M. Ramond in the Memoires de V Institute vol. vi., and M. Daubisson in the Journal des Mines, February 1807, have recently brought to perfection, the method of measuring altitudes by means of the barometers. Their memoirs are highly deserv- ing of being translated into English : it is at least certain, however, that it would be agreeable to the geologists of this country, and to those of foreign nations who make use of instruments graduated in the English way, if the second of the two methods of M. Ramond was reduced into the mea- surements of this country. This second method has the ad- vantages over the first of being the most expeditious, and at the same time almost imperceptibly exact. I have under- taken this task, and shall be happy to see it inserted in your Journal, if you find it worthy of publication.
The principal part of this work consisted in the reduction of the table of M. Ramond ; the object of which is, to have a view in calculation, to the gravity at different parallels of latitude at which we take observations. His second method abridges considerably his first; and, in my opinion, all an- tecedent methods where exactitude was the object in view. I subjoin this table calculated upon the co-efficient 10057*6 fathoms, which corresponds to 18393 metres, being that of M. Ramond.
You will perceive that the result of the calculation, ac- cording to my reduction, gives the altitudes in fathoms in place of giving them in feet as in England. In this trifling change, I find two advantages : In the first place it renders the calculation a little shorter; and secondly, it presents the altitudes in numbers more easily fixed in the imagination than more complicated numbers. In short, we cannot form
* For this communication we are indebted to a learned foreigner now in London.
Vol. 33. No. 130. Feb. 1809. G a very
98 On Barometrical Measurements*
a very distinct idea of the height of a mountain, when we stale it as 1Q000 feet, whereas three miles and some fathoms will impress, the real height much more strongly on the mind. The examples subjoined show the method ; and I presume will require no further illustration to those who are ac- quainted with logarithms. I shall only observe, that in re- ducing the metre to fathoms, I have made use of the report which I found in the Memoirs of the Royal Institution, vol.i., namely, lni39*371 English inches : and with respect to the thermometer, I have made use of the well known re- port 100 : 1 SO, those two numbers marking the space of the scale comprehended between the freezing and boiling points : thus in calculation the degrees of Fahrenheit should be di-
o
minished 32° for the degrees above the freezing point, and on the contrary with respect to the degrees below melting ice, they must be retrenched from 32°.
I am your very obedient servant,
De J — =-.
January 1809.
Note — In the first of the following examples I have ap- plied to the least height of the barometer, the difference of the thermometers which are attached to them, because the thermometer was lower than in the other.
In the second example it is the contrary, because the thermometer attached was highest at the station where the barometer was lowest. The rule is to augment the height of the column of mercury, in the coldest station, by so much as ^-^ as there are degrees of different between the thermometers of correction. The perusal of JS^^lamond's Memoir will greatly assist the reader on this subject.
Example.
On Barometrical Measurements,
99
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On Barometrical Measurements,
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Table
On Barometrical Measurements* 101
Table of the Logarithms of the Coefficients calculated for different Latitudes — Supposing the coefficient equal to 10057*6 fathoms for the 45 degrees.
|
Latitude |
Logarithms. |
Latitude. |
Logarithms. |
|
1° |
4-0037276 |
37°, |
4*0028344 |
|
2 |
7254 |
38 |
7930 |
|
3 |
7215 |
39 |
7510 |
|
4 |
7164 |
40 |
7087 |
|
5 |
7097 |
41 |
6662 |
|
(> |
7014 |
42 |
6234 |
|
7 |
6917 |
43 |
5805 |
|
8 |
6816 |
44 |
5375 |
|
9 |
6683 |
45 |
4944 |
|
JO |
6540 |
46 |
4513 |
|
n |
6385 |
47 |
4083 |
|
12 |
6217 |
48 |
3654 |
|
13 |
6035 |
49 |
3226 |
|
14 |
5839 |
50 |
2801 |
|
15 |
5630 |
51 |
2378 |
|
16 |
5609 |
52 |
1958 |
|
17 |
5174 |
53 |
1544 |
|
18 |
4927 |
54 |
1131 |
|
19 |
4668 |
55 |
0723 |
|
20 |
4397 |
56 |
0321 |
|
21 |
4114 |
57 |
4-0019924 |
|
22 |
3820 |
58 |
9534 |
|
23 |
3516 |
59 |
9194 |
|
24 |
3201 |
60 |
8774 |
|
25 |
2876 |
61 |
8404 |
|
26 |
2541 |
62 |
7048 |
|
27 |
2197 |
63 |
7691 |
|
28 |
1845 |
64 |
7347 |
|
29 |
1484 |
65 |
7012 |
|
30 |
1114 |
66 |
6687 |
|
31 |
0737 |
67 |
6372 |
|
32 |
0354 |
68 |
6068 |
|
33 |
4-0029964 |
69 |
5774 |
|
34 |
9567 |
70 |
5491 |
|
35 |
9165 |
71 |
5220 |
|
36 |
,8757 |
90 |
£604 |
G3
XVIII. A
[ 102 ]
XVIII. A Letter on the Alterations that have taken place in the Structure of Rocks, on the Surface of the basaltic Country in the Counties of Derry and Antrim. Addressed to Humphry Davt, Esq.> Sec. M.S. By William Richardson, D.D, *
SIR,
i. request you will be so good as to lay before the Royal Society the following observations on the Natural History of that part of Antrim, (contiguous to the-Giant's Cause- way,) which you and I examined so carefully together. I know not any country that deserves so well to have its facts faithfully recorded; from the important conclusions to which they lead.
The basaltic area (taken in its whole extent) comprehends the greater part of Antrim, and the east side of Derry to a considerable depth.
In a geological point of view, nature f has been very kind to this district, for not content with assembling together in a small space so many of her curious productions, and ar- ranging them with more regularity and steadiness than in any other country described, she has condescended occa- sionally to withdraw the veil, and Jay herself open to view, often exhibiting a spectacle equally gratifying to the admirer of magnificence, and to the curious naturalist, who can here, by simple inspection, trace the arrangements which are to be discovered elsewhere, only by penetrating beneath the surface of the earth.
As soon as we enter the basaltic area, we begin to per- ceive traces of these arrangements; as we advance further north, they increase; and in the tract near the shore, and especially at the island of Utithliri, which seems to have come fresher from the hand of nature than the rest of our area, the stratification of the whole is perfectly visible, and
* From Philosophical Transactions for 1808.
•J- By the word nature, which frequently occurs in the course of this Me- moir, I always mean, according to Pvay's definition^ the wisdom of God in the creation of the world.
~ r-k the
On the basaltic Surface, &c. 103
the nature of the several strata laid open to us at their abrupt and precipitous terminations.
To the southward we perceive the distinctive features abate, and wear away ; the basaltic stratification indeed re- mains, but is no longer displayed to us in the same manner; the neat, prismatic, internal construction of the strata, which occurs so frequently on, and near, the coast, is scarcely to be met with at a distance from it ; a rude columnar ap- pearance is all we find, and that but rarely.
Tt is at the periphery of our area, and especially at its northern side, that every thing is displayed to the greatest advantage ; here we have perpendicular facades often con- tinuous for miles, and every separate stratum completely open to examination.
Of these facades, four are more distinguished by their grandeur and beauty than the rest, Magilligan Rock, Cave Hill, Bengore, and Fairhead.
The two former are at the extreme points of the north- west diagonal of our area, and nearly forty miles asunder ; they are at the summits of mountains, and accessible by land.
The precipitous faces of Fairhead and Bengore, to which I had the pleasure of attending you, and which are visible only from the sea, are the most beautiful, and the most curious ; for the strata, which at Magclligan and Cave Hill, are all nearly similar, at Fairhead and Bengore are much di- versified. Of Fairhead I have already published an account in Nicholson's Journal for December, 1801, and I now propose to execute an intention which I have had for some years of giving a minute account of Bengore.
I am aware that it will be extremely difficult to convey a clear and adequate idea of an assemblage of 16 strata, (for such is the number of which our promontory is composed,) appearing and disappearing at various altitudes, yet retaining each its own proper place, and forming together a most beautiful and regular whole, though never considered as such before.
But as I have the aid of very correct views of the most important parts of the facade, to the accuracy and fidelity
G4 of
104 On the lasaltic Surface of the Counties
pf which I have already obtained your testimony — I shall venture to proceed, for I am anxious to bring into notice the most complete exposure of the internal structure of a district, that I have seen or read of; as there i9 little likelihood that any other person will enjoy the opportunities which I have had for so many years, of exploring this interesting part of our coast, through a turbulent sea, and rapid tides.
Description of the Promontory of Bengore, and its Stratification.
This promontory commences at the termination of Bush- foot Strand, where the coast, the general direction of which for several miles had been due east and west, turns to the north-east, and, after being cut into several semi-circular bays, deflects to the S.S.E. and near the old castle of Dunseverick, resumes its former rectilineal and nearly eastern direction.
The promontory occupies the interval between Dunscve- rick, and the Black Rock, at the end of Bushfoot Strand, about four English miles; the facades commence at Black Rock, and increase in height until we reach Pleskin, where the perpendicular part at the summit is 170 feet, and the precipitous part from the bottom of the pillars to the sea 200. As we proceed on from Pleskin to Dunseverick, the height gradually abates, and is finally reduced to about 100 feet.
In this whole space, wherever the precipice is accurately perpendicular, the several strata are easily distinguished from each other, but where the slightest obliquity prevails, a grassy covering is formed that effectually conceals all beneath it; hence the face of the precipice seems much diversified ; the columnar strata in some places only exhibiting detached groups of pillars, while in others they form extensive colon- nades.
I shall now state the appearances as we approach, and coast the promontory from the westward, noticing in this first view of the precipice, every thing that may be consi- dered as general, and reserving (as I did with you) for my return in the contrary direction, a detailed account of the strata taken separately.
The first circumstance, that occurs to the attentive ob- server
of Derry and Antrim. 105
server on his approach, is, that although both the promon- tory itself, and the strata composing it, ascend to the north- ward, yet it is not in the same angle, the strata being more inclined to the horizon than the line tracing the surface of the promontory, a fact which I shall account for afterwards.
From the Black Rock to the Giant's Causeway (about a mile) the materials, and their arrangement, are similar to those of the coast to the westward, viz. strata of table basalt, generally separated by thinner strata of a reddish substance.
At the Giant's Causeway a new arrangement commences, one of the little systems I have mentioned in other memoirs, • by the aggregate of which our coast is formed ; nature having changed her materials, or their disposition, or both, every two or three miles. To the system of strata comprehended between the Giant's Causeway and Dunseverick I now limit myself, as all the strata composing it emerge between these two points.
As we proceed along the coast from the Giant's Cause- way eastward, we perceive the whole mass of strata ascend gradually, culminate at the northern point of the promon- tory, and then descend more rapidly, as the land falls away to the south-east, until having traced them across the face of the precipice we see them immerge separately at and be- yond Portmoon Whyn Dykes.
The western side of the promontory is cut down perpen- dicularly, by eleven IVhyn Dykes ; the intervals between them are unequal, but they all reach from the top of the precipice to the water, out of which some of them again emerge in considerable fragments ; they are all constructed of horizontal prisms, which are strongly contrasted with the vertical pillars of the strata through which they pass.
One of the dykes at Port Cooan, on Bengore, half a mile from the Giant's Causeway, is very beautiful; an insulated rock about 16*0 feet high, and 20 in diameter, stands per- pendicular in the middle of a small bay ; the main body of the rock is similar to the contiguous consolidated masses ; but on the east side a singular whyn dyke is joined to it, composed (as they often are) of several walls agglutinated together, with wall-like fragments of other parts of the dyke
emerging
\06 On the basaltic Surface of the Counties
emerging at their base ; the solid mass of dyke is seen cutting down the precipice to the southward at 150 yards distance.
Depression of the Strata,
Soon after we have passed the last of our wbyn dykes at Port Spagna, (a name derived from" a vessel belonging to the Spanish armada having been driven ashore in that creek,) we discover a new and curious circumstance, viz. that the western half of the promontory has sunk or subsided be- tween thirty and forty feet, without the slightest concussion or derangement of the parallelism of the strata.
Two other depressions appear as we proceed onwards, one at Porlmoon, and the other at the angle where the pro- montory begins to project from the rectilineal coast ; these however are far less considerable in thickness than the pre- ceding, neither of them exceeding five feet.
Such depressions occur at the collieries near Balk/castle, and generally on one side of a whyn dyke. We have also at Seaport, two miles west from the Giant's Causeway, a dyke oblique and undulating, with a depression of the strata of about four feet on one side ; but on Bengore promontory our dykes are unaccompanied by depressions of the strata, and where we have depressions we do not find a trace of a dyke.
The portions of tins extensive facade, which I have se- lected for explanatnrv views, are Portmoon, in or near which most of the strata emerge, and Plvskin, where the strata culminate : each of these views, too, exhibits one of our de- pressions ; but in that of Ple<kin the first apparent de- pression is purely- an optical effect arising from the position of my friend major O'Neal, of the 5Gth, who took his view from the water.
Enumeration of the sixteen Strata that compose the Promon- tory of Bengore, taken in their regular Order, and count- ing from above.
The country immediately to the southward of Bengore is like the promontory itself, a stratified mass, accumulated to the summits of Craig Park and Croaghmore, the first five hundred and the second seven hundred feet high; but with
those
of Derry and Antrim, \o?
these strata I have nothing to do, limiting myself to those alone of which the promontory is formed, and which' are exhibited in its facades.
The uppermost of these commences near half a mile to the eastward of the angle, where the coast deflecting from its due east and west course, turns to the north-west, and be- gins to form the promontory.
So far the course of this stratum is to appearance perfectly horizontal ; for the strata all ascending to the north, the in* tersection of their planes with the plane of the sea must run east and west, that is, in the present case it coincides with the direction of the coast. i
But when the coast changes its direction, this coincidence ceases, and the facade (that is the vertical section of the coast) losing its east and west course, its strata must appear to ascend towards the point it turns to ; therefore the strata at Porttnoojt, and along the north-east side of the promon- tory, should ascend obliquely along the facades, as they ac- tually do.
First Stratum, (m).
The stratum I commence with forms the whole facade, from its first appearance until it reaches the promontory ; it consists of massive pillars rather rude, and about sixty feet long, its course for half a mile (as I have stated) seems ho- rizontal, but on the face of the promontory it ascends, and continues to rise uniformly until it reaches the summit, which it lines as far as Portmoon, on the south side of which it loses some of its thickness^ then suddenly disappears and vanishes from that facade, receding westward in the form of a stony ridge, and is seen no more.
Second Stratum, (It). The stratum upon which the preceding rests, is red as- brick, and about nine feet thick; it appears in spots and patches just above high water mark, so long as the incum- bent stratum continues horizontal, but when that rises ob- liquely, the second ascends with it ; it is now completely displayed^ and having supported the preceding in its course
to
108 On the basaltic Surface of the Counties
to the summit, vanishes with it (at x in the view of Port" mnon), and is seen no more*
These ochreous matters, so common in all basaltic coun- tries, according to Mr. F. St. Fond's opinion, were once pure basalt, but have undergone some chemical process of nature we are unacquainted with, by which their colour has been changed.
Third Stratum , (i).
The next stratum is the last of those composing the pro- montory which appears beyond it; for so long as the first and second continue their horizontal course towards Bevgore, this third accompanies them, showing its upper surface be- tween high and low water- mark ; but when it ascends along with the others across the facades ir displays its whole thickness, above fifty feet.
This stratum is of that variety of basalt, I have on diffe- rent occasions distinguished by the name irregular prismatic ; it resembles the columnar basalt in grain, but differs from it totally in principle of internal construction, for its prisms are small, not articulated, and indifferent as to the position of their axes, which is perpetually changing.
The irregular prismatic basalt accompanies the columnar in most countries, as at Pont dti Baume, at Trezza, at Bol- sena in the Sound of Mull, and at Staffa. In Antrim, it is very common ; and here is a striking resemblance between the rock crowning the celebrated columns at Staffa, and a stratum covering a very neat colonnade at Crai galiullur , near Portrush.
This stratum (as is well exhibited in the view of Port- moon) is scolloped off irregularly from the point where it be- comes superficial (x), until it completely disappears at (?■)> a thin stripe of its lower edge alone is ever resumed again.
Fourth Stratum, (h). The next three strata will require only very short descrip- tions; the fourth is about seven feet thick, entirely colum- nar, the pillars small, but not neat : they appear very white from a thick covering of Byssus saxatilis, which shows a great predilection for this sl'a'uro.
Fifth
of ' Derry and Antrim, 109
Fifth Stratum, (g).
This stratum is ochreous, and more of a slate colour than any of the other red strata ; as it is friable, it soon acquire* a grassy coat, through which it is only in spots that it shows its proper colour; it is about eight feet thick.
Sixth Stratum, (f) .
This stratum is composed of rude massive pillars so coarsely formed, that on the least abatement of perpendicu- larity the columnar form can scarcely be traced. This stra- tum is about ten feet thick, it forms the vertex of the beau- tiful conical island Beanyn Daana, and is marked in the views (f).
These last strata, though they have nothing very remark- able in themselves, nor contribute much to the beauty of the facade ; yet they exhibit one of the most important facts I am acquainted with in natural history, and which, when attentively considered, throws much light on the nature of the operations performed upon our globe since its consolida- tion, and leads us irresistibly to conclusions extraordinary and unexpected.
The fourth, fifth, and sixth strata reach the top of the precipice, and vanish together at the waterfall in the north- west corner of Portmoon. When they come to the surface, they turn inland to the westward in long stony ridges ; these obstruct the course of the waters in their descent along the inclined plane, formed by the surface of the promontory, and throw them over the precipice, in a cascade highly beau- tiful after rain.
On the facades to the north-west not a trace of them ap- pears, these being entirely formed by the lower strata, which I have not yet noticed ; but at the distance of a mile, at the great depression (already mentioned), the fourth, fifth, and sixth strata, with a narrow stripe of the third, suddenly ap- pear, in their regular posts, their proper order, and with all the characteristic marks peculiar to each separate stratum.
In the interval between the depression at Pleskbt, and the Giant's Causeway (about a mile), these three strata often
appear
110 On the basaltic Surface of the Co?mties
appear in a desultory way on the summit of the precipice, wherever it is of sufficient height to receive them, always preserving their usual thickness, their characters, and their order ; so that a person master of the order I am detailing, as he approaches a rising point of the precipice, can tell its strata, and their order, before he is near enough to distill* guish them.
Seventh Stratum, (d).
The rude and massive pillars of the sixth stratum pass into the neater, and much longer columns of the seventh, without interrupting the solidity or continuity of the material ; exact- ly as a down-held hand appears to separate into fingers. The thickness of this stratum, that is the length of the pillars of which it is formed, is fifty -four feet ; it is marked {d) in the two views, and in its passage across the face of the precipice, displays more beautiful colonnades than any of the others.
This seventh stratum emerges from the beach immediately behind the south-east point of Portrnoon, and where it first shows itself in that bay, has its lower edge raised only a few feet above the water ; it forms the upper frustum of the larger of the two conical islands, ascends obliquely along the face of Portrnoon, and continues to rise until it com- poses the upper range in the beautiful facade, properly called Bengore Head. This is probably the most magnificent of all, its convexity towards the sea producing a fine effect. The lower edc;e of this stratum, that is the line forming the base of its pillars, has here, as at Pleskin, attained the height of three hundred feet above the water.
The seventh stratum, like those above it, also suffers an interruption; for after having exhibited itself to such great advantage at Bengore, the extreme northern point of the promontory lowers, and this stratum disappears for about one-third of a mile ; as the promontory rises, it is resumed again in great beauty at Pleskin, and is interrupted no more; we scarcely ever lose sight of it until we reach Port Noffer (the next bay to the Causeway) ; here, for want of perpen- dicularity it is little seen, and is finally lost over the cause- way, we know not well how.
Eighth
of D err y and Antrim. Ill
Eighth Stratum, (c) .
The next stratum is of the same variety of basalt with the third, that is, irregular prismatic; it is fifty-four feet thick, and in the views distinguished by the letter (c) : where it emerges at the south-east corner of Portmoon, it is quite ac- cessible by land, and affords the best opportunity I know for examining this species of basalt, as it is there very neat.
There is little more of this stratum seen in the facade of Portmoon for want of perpendicularity, but it forms the lower frustum of the great conical island Beany n Daana% and the whole of the smaller, except the base ; it is well dis- played over the remainder of the precipice, it forms the in- termediate stratum between the magnificent colonnades at both Ban gore and Pleskin, and finally is lost just over the Giant's Causeway. Large globular fragments have fallen from it, and are scattered about the causeway.
Ninth Stratum, (b).
This stratum is forty-four feet thick, that being the exac£ length of the neat pillars composing it ; at its emersion it forms the bases of the two conical islands in Portmoon, and is no more seen in that bay, but immediately to the north- ward it begins to show itself in colonnades and groups, some of them resembling castles and towers.
It ascends along the precipice obliquely, like those above it, forms the lower range at Bengore and Pleskin, from which last it dips to the westward regularly, composes the group at Port Naffer, called the Organs, seen from the causeway, and finally at its immersion, or intersection with the plane of the sea, it forms the beautiful assemblage of neat pillars, so long distinguished by the name of the Giant' i Causeway.
At these two intersections, each of them accessible by land and water, the prisms exactly resemble each other in grain, size, and neatness ; the interval between them is full two miles, through great part of which this stratum is dig- played at different heights; it culminates between Pit- and Bengore, with its lower edge more than two hundred feet above the water.
a We
US On the lasaltic Surface of the Counties
We see now what a diminutive portion of our vast basal- tic mass has, until lately, monopolized the attention of the curious; and even after it was discovered that we had many other, and much finer collections of pillars on the same pro- montory, it never occurred to those who were preparing to give accounts of them to the public, to examine whether these were mere desultory groups, or detached parts of a grand and regular whole, which a more comprehensive view of the subject would soon have laid open to them.
Tenth Stratum, (a).
The stratum upon which the pillars of the preceding rest, is ochreous, red as minium, and about twenty feet thick ; it is scarcely seen at Portmoon, a patch alone of its surface being distinguishable under water at low tide ; but imme- diately to the northward it shows itself, and from its bright colour, makes a conspicuous figure across the fa.ee of the precipice in a course of more than a mile and half; its last appearance to the westward is at Rovlnvalley , the opposite point of the bay from the Giant's Causeway, from which we have a good view of it. The final dip and immersion of this tenth stratum, as well as its emersion, are lost for want of perpendicularity.
The six remaining strata are all similar in material, but differing much from each other in thickness ; they are all of that description called tabular basalt, sometimes showing a faint disposition to assume a columnar form at their edges, and alwavs separated from each other by o?hreous layers.
These six strata are not so perfectly distinct as those above them, for sometimes we think we can count seven, and again not more than five ; nor does each of these preserve the same thickness through their whole extent, for they are deeper towards the northern point, where they culminate, forming by themselves a perpendicular facade near two hun- dred feet high, but they grow thinner as they recede from- this centre.
The. jets of black rock in the view of Portmnon, are the emersions of these strata ; their last appearance on the west side is at Rovinvalley, where they strongly display the incli- nation
of Dairy and Antrim. 113
nation of their strata, (the same with all the rest) to those approaching from the westward ; their final immersion is lost for want of perpendicularity.
I shall now proceed to select from the great mass of facts that are exhibited on the face of Bengore promontory, and occur in the contiguous basaltic country, such as seem ap- plicable to geological questions, and likely to throw light on such subjects.
Facts applicable to geological Questions.
1 . Every stratum preserves accurately, or very nearly, the same thickness through its whole extent, with very few ex* eeptions.
2. The upper and lower surface of each stratum preserve an exact parallelism, so long as they are covered by another stratum j but when any stratum becomes the superficial one, its upper surface is scolloped, or sloped away irregularly, while the plane forming its base continues steady and rec- tilineal ; but the parallelism of its planes is resumed as soon as another stratum is placed over it.
3. The superficial lines bounding the summit of our fa- cades, and our surface itself, are unconnected with, and unaffected by, the arrangement of the strata below them.
4. Nature^ in the formation of her arrangements, has never acted upon an extensive scale in our basaltic area, (at least on its northern side, where our continuous precipices enable us to determine the point with precision,) but changes her materials, or her arrangement, or both, every two or three miles, and often at much smaller intervals.
5. Wherever there is a change of material, as from one stratum to another in a vertical line ; or where the change is in a horizontal direction by the introduction of a new sy- stem j or where a whyn dyke cuts through an accumulation of strata; in all these cases the change is always per salt um and never per gradus, the lines of demarcation always di- stinct, and well defined ; yet the different materials pass into each other without interrupting the solidity and con- tinuity of the whole mass.
6\ The facades on our coast are formed as it were bv vef- Vol. 33. No. 130, Feb. 1609. H ' tical
114 On the basaltic Surface of the Counties
tical planes, cutting down, occasionally, the accumulations of our strata; the upper part of these facades is generally perpendicular, the lower steep and precipitous.
7. The bases of our precipices commonly extend a con- siderable way into the sea; between the water and the foot of the precipice, (and especially near the latter,) there is fre- quently exhibited the wildest and most irregular scene of confusion, by careless observers supposed to be formed by the ruins of the precipice above, which have fallen down : such, no doubt, was Mr. Whitehurst's idea, when he de- scribes one of these scenes as " an awful wreck of the terra- queous globe."
But a more attentive observer will soon discover that these capricious irregularities, whether in the form of rude cones, as at Beany n Daana, and the west side of Pleskln ; or towers, as at the dyke of Port Cooan and Castro Levit, at the foot of Magilligan facade, even spires and obelisks, as to the westward of Kenlaan, and at the Bull of Rat kim ; yet all of these once formed part of the original mass of coast, stratified like it, and their strata still correspond in material and inclination with those in the contiguous pre- cipice.
8. These vertical sections or abruptions of our strata are by no means confined to the steeps that line our coast ; the remaining boundary of our basaltic area has several of them equally grand ; and similar abruptions, or sections, (though not bo deep,) are scattered over a great part of our area, and especially on the ridges of our hills and mountains which are cut down in many places like a stair, by the sudden abrup- tion of the basaltic stratum.
9 Wherever the strata are thus suddenly cut oft", whether it b*jg a ruasfi of aecumulated strata as in the facades on our • coast, or solitary strata in the interior; the materials on one side of the abruption are completely carried away, without a fragment being left behind, while on ii^> other side the un- touched stratum remains entire and undisturbed.
I shall not proceed to apply these facts to support, or in- validate, any of the numerous theories whieh have given rist to io much controversy, in which I myself (as you
know)
of Berry and Antrim . 115
know) have borne some part ; I shall look to nature alone., without much reference to opinions, and shall endeavour to trace, by the marks she has left behind her, some of the grayd operations she once executed on the surface of our globe.
Varro divided1 the time elapsed since the beginning of the world into three portions, which he distinguished by the names, prolcpticum, fabulosum, and kistoricum.
The first comprehended the period of absolute darkness; in the second some faint lights were thrown upon the his- tory of its events, by fable and tradition; in the third, the historian had the common aids from which history is usually compiled.
The natural history of the world seems to admit of a cor- responding division. In the first I include the formation of our strata, their induration, their derangement from the horizontal position in which they seem originally to have been placed, and the operation of cutting them down by so many why'n dykes.
In the second division, corresponding to Varro's falulo- S7im, I comprehend the operations performed upon our globe, posterior to its final consolidation, and antecedent to all history or tradition ; operations therefore that can be established by the visible effects alone which still exist, written in strong characters.
The third division contains the period since we acquired some knowledge of natural history, became acquainted with causes and effects, and able to trace the connection between them.
With the operations performed in the first division (cor- responding with Varro's prolepticum) modern theorists as- sume that they are well acquainted, able to account for every appearance, and to detail the whole process of original for- mation. I however shall decline noticing these early pro- cesses of nature, and limit myself to the second division of natural history, hoping from the prominent features of my country that remain still undefaced, and from its curious facts, to trace and demonstrate the great effects that have been produced upon our surface; and though I do not pre-
H 2 sume
116 Some Experiments on the Distillation
sume to advance further, T perhaps may assist in clearing the way for future naturalists, and, by establishing effects, encourage them to proceed to causes, and help them to dis- cover the powers and agents by which these grand opera- tions have been executed.
[To he continued.]
XIX. Result of some Experiments on the Distillation of various Fegetahle and Animal Substances in the dry Way. By David Mushet, Esq.
[Continued from p. 10.]
Experiment XXI II.
JJittfr Almonds, 240grains. — In distillation they discharged a great quantity of smoky flame. The. almonds were found without adhesion to each other, and contained upon their surface a great variety of prismatic colours. The coal was found to weigh 32 grains : 208 grains having been lost by the distillation.
Component parts : Volatile matter 80*66 Oxide of carbon 10/34:
100 parts.
Experiment XXIV. Black Pepper, not ground, 240 grains. — In distilling, i considerable portion of flame was disengaged. The coal ob- tained was partially prismatic. Every spherule of pepper preserved its original form. A few masses slightly adhered together without any appearance or reality of welding. Weight of the coal 53 grains. Loss by distillation 187 grs. Component parts : Volatile matter 77*91 Oxide of carbon 2209
100 parts.
Experiment XXV. White Pepper, 240 grains. — This substance flamed a good ileal in distilling, of a pure white colour, edged with pale
blue.
of Vegetable Substances. 1 1 7
blue. The product in coal was clear, and shining, each corn entire, and partially connected in groups, which, how- ever, separated upon being exposed to air. Weight 50 grains; having lost by distillation 1QO grains.
Component parts : Volatile matter 79' \6 Oxide of carbon 20*84
100 parts.
Experiment XXVI.
Fine Black Tea, 240 grains— The result of this distillation was a slightly prismatic coal, to appearance very little al- tered in shape, bulk, or colour. It weighed 74 grains. Loss in distillation 166 grains.
Component parts : Volatile matter 69' 16 Oxide of carbon 30*84
100 parts.
Experiment XXVII. Gunpowder Tea, 120 grains. — This substance afforded a small portion of flame during the operation of distilling. The result was a firm compact coal, thoroughly welded to- gether by means of a silvery-gray species of coal, perhaps of resinous extraction. The whole surface of the mass, wnich resembled in shape the interior of the retort, was covered with fine prismatic shades. The grains of tea had not^ though welded, lost any part of their shape. The coal thus obtained weighed 39 grains. Loss by distillation 81 grains. Component parts : Volatile matter 67*5 Oxide of carbon 32*5
100 parts.
Expcrim ent X X V II I .
Coffee Beans, 240 grains. — The distillation of this substance disengaged a considerable portion of (lame. The beans were found in the state of a beautiful prismatic coal of the most lively and elegant shades. The whole were destitute of ad- hesion, and seemed to possess nothing of the welding pro-
H 3 perty.
118 Some Experiments on the Distillation
perty. They now weighed 45 grains, having lost 195 grains by distillation.
Component parts : Volatile matter 81*25 Oxide of carbon 18*75
100 parts.
Experiment XXIX.
Dutch Cheese, 270 grains. — After a distillation, which wa§ attended with the discharge of a watery-coloured smoky flame, a rough sooty coal was found, without any symptoms of welding.- It was salt to the taste, and in distilling emit- ted strong fumes of muriatic acid gas. The coal weighed 48 grains, 222 having been lost by distillation.
Component parts : Volatile matter 82*22 Oxide of carbon 17*78
100 parts..
Experiment XXX.
Scotch Cheese (Dun lop), 300 grains. — This cheese flamed violently during the distillation. The colour of the flame approached near to that of thick oil, and deposited a con- siderable portion of soot. The resulting coal was much shrivelled, possessed nothing of the welding property, and weighed 25 grains, having lost by distillation 275 grains. The colour of this coal was grayish black, and saltish to the taste. ' It was not, however, nearly so pungent as that ob- tained from the Dutch cheese in the former experiment. Component parts : Volatile matter 91 66 Oxide of carbon 8*34
loo parts.
Experiment XXXI.
Cheshire Cheese, 300 grains. — The discbarge of flame in the distillation of this cheese was still more violent than in the two former. The coal was reduced to a mere skeleton. The colour brownish black, with a small perception of salt. It weighed 15 grains. Loss 285 grains.
Component
of Animal Substances. 1 1 9 :
Component parts : Volatile matter 95 Oxide of carbqn 15
100 parts,
It would appear by the Experiments from Ex per. XIII, inclusive, with the exception of the gunpowder tea, that the coajs obtained from these various substances do not con,^. tain the welding or caking principle ; and so far they re-- semble the residual coals, or oxides obtained from the di- stillation of all the woods.
The following experiments are selected from a variety made with animal substances.
Experiment XXXII. Beef, entirely freed from fat, 1121 grains.-r-This in distil- lation gave out a light blue penetrating smoke, which to- wards the middle of the operation became particularly of- fensive. Towards the close a blue lambent flame appeared, which continued to twitter for some time ; after this, all of- fensive smell ceased, and a skeleton coal of a pure black colour was obtained perfectly insipid, which weighed 34. grains ; 1087 grains having been lost by distillation.
Component parts : Volatile matter 97
^ • Oxide of carbon 3
100 parts. ■
Experiment XXXIII. Fat, cut from the same beef, 425 grains. — This was slowly distilled, and with a moderate heat, so as to restrain the flame. After ignition there was found in the bottom of the retort a long flake of carbonaceous matter that weighed three grains. Loss by distillation 422 grains.
Component parts: Volatile matter 99*29 Oxide of carbon 00*71
100 parts. ¥L 4 Experiment
120 Some Experiments on the Distillation
Experiment XXXIV. Mutton, cut from the thick part of a hind-quarter and carefully freed from fat, 775 grains. — This suhstance exhaled the same disagreeable odour as the beef, but was succeeded by a flame that burnt longer and with more violence. The coal obtained was light and honeycombed, of a dark grav colour, and weighed 23 grains. Loss by distillation frifiS grains.
Component parts : Volatile matter 95*74 Oxide of carbon 4*28
100 parts.
Experiment XXXV. J?at, cut from the same quarter, 225 grains. — A thin flat cake of silvery gray coal was obtained, which weighed 2' 25 grains. — Lost in distillation 223*75 grains.
Component parts : Volatile matter 99 Oxide of carbon J
100 parts.
Experiment XXXVI. Veal, carefully separated from fat, 1215 grains — The re- sult of the distillation of veal gave a fine silvery gray co*- loured coal, light, and extremely spongy, weighing 44 grains. — Loss by distillation 1201 grains.
Component parts : Volatile matter 9647 Oxide of carbon 3*53
\ 100 parts.
Experiment XXXVII. Lean of Pork, 820 parts. — This flamed a great deal, and yielded a coal of considerable bulk, but very light and spongy. The colour was silver gray. It weighed 49 parts, having lost by distillation 771.
Component parts : Volatile nutter 94*03 Oxide of carbon 5*97
100 parts. Experiment
of Animal Substances. J21
Experiment XXXVIII. AToad, weighing 554 grains. — This was introduced into a retort, and distilled with nearly the same attendant circum- stances as in the experiments immediately before. At the commencement of the operation a violent hissing was per- ceptible, accompanied with slight explosions. The result was, the skeleton nearly in the position in which it was ori- ginally placed. The flesh and skin had disappeared, and left a very perfect coal adhering to the bones, all of which were converted into a beautiful white colour,^ — The carbonaceous matter weighed 94 grains ; the bones, some of which soon fell into powder, 7 grains : — total 31 grains. Loss in the distillation 523 grains.
Toad : Volatile matter 94*40 Lime - 1-26
Oxide of carbon 4*34
100 parts.
Experiment XXXIX, An Eel, weighing 704 grains, and newly killed, was boil- ed up and put into the retort, and exposed till all smell of animal had ceased. A mass of coal was found attached to the slender bones of the animal, and in the same position it originally occupied. It was not easily possible to separate the bone. The whole weighed 28 grains, having lost in distillation 676 grains.
Component parts of eel : Volatile matter 96
Oxide of carbon 4
100 parts.
Experiment XL.
While Snails, 340 grains. — These in distillation formed a pretty firm mass of caked coal of a dull black colour. The same penetrating smell of animal matter was perceived in this experiment as in the former. The coal weighed 21 grains -9 319 grains having been lost by distillation. *. Component
152 Experiments on the Distillation of Animal Suhstances.
Component parts o.f white snails : Volatile matter 93*82
Oxide of carbon 6*18
100 parts.
Experiment XLT. Black Snails, 6*37 grains. — A shrivelled coal was found to be the result of the distillation of these animals, mixed with nearlv one-third part of caustic lime of a gray earthy colour : the whole weighed 30 grains; the loss by distillation having fccen 587.
Component parts of black snails: Volatile matter 9215
Oxide of carbon 7*85.
100 parts,
Experiment XLU. Earth Worms, that had been kept for some weeks to cleanse themselves, 1000 grains. — A considerable quantity of gas was evolved during the distillation, and the usual smell of the combustion x>f animalmatter. A firm bulky mass of coal weighing 130 grains was obtained, mixed with concretions of earthy matter. Loss by distillation 870 grains,
Component parts : Volatile matter . 87
Oxide of carbon "J mixed with earths J
100 parts.
Tt is rendered highly probable from these experiments, that eXery animal substance contains a portion of oxide of carbon ; and many of those that exhibit but a small residuum in the state of coal, part with a considerable quantity in the state of £,as and flame, dissolved in hydrogen, but which is lost from a recompounding affinity not being pre- sent at the period of disengagement. From this circum- stance most probably may arise, in part, a well established fact, that the same quantity of any of the substances before operated upon, will communicate a greater share of carbo- naceous matter when in a raw state, than the same sub- stance
Hydraulic Bivestigaiions. \ £3
stance carefully converted into charcoal, and afterwards ap- s plied to the same purpose. The substances being so varied and numerous that contain the oxide of carbon, it could not possibly follow that the extent of their carbonaceous effects would be in the proportion of their masses under similar circumstances, nor that the charcoal or oxide that each of them afforded by distillation would bear the same relation to each other in point of purity, even where the acknow- ledged quantity of alloy in the state of earths, salts, &c, were the same. We therefore find, that even in the state of the raw substance equal weights or quantities of matter, calculating always upon the residuum alloys of different substances, produce results materially different, which can only be attributable to the different existing stale of the oxide, or to the decomposition of the hydro-carbonate which most of them contain. The difference of the results becomes much greater when the oxide of carbon is used in the state of charcoal or coke, and the variety of the results here also obtained, where no hydro-carbonate comes into action, can only be placed to the state of oxidation of the carbon.
In a future communication I shall illustrate, by some ex- periments, what I have just stated.
XX. Hydraulic Investigations, subservient to an intended Croonian Lecture on the Motion of the Blood. By Thos. Young, M.D. Fur. Sec. R.S*
I. Of the Friction and Discharge of Fluids running in Pipes 9 and of the Velocity of Rivers.
Waving lately fixed on the discussion of the nature of in- flammation, for the subject or an academical exercise, I found it necessary to examine attentively the mechanical principles of the circulation of the blood, and to investigate minutely and comprehensively the motion of fluids in pipes, as affected by friction, the resistance occasioned by flexure, }he laws of the propagation of an impulse through the fluid
* From Philosophical Transactions for 1808.
contained
l£4 Hydraulic Investigations,
contained in an elastic tube, the magnitude of a pulsation in different parts of a conical vessel, and the effect of a con- traction advancing progressively through the length of a given canal. The? physiological application of the results of these inquiries I shall have the honour of laying before the Royal Society at a future time ; but I have thought it ad- visable to communicate, in a separate paper, such conclu- sions, as may be interesting to some persons, who do not concern themselves with disquisitions of a physiological na- ture; and I imagine it may be as agreeable to the Society that they should be submitted at present to their considera- tion, as that they should be withheld until the time ap- pointed for the delivery of the Croonian Lecture.
It has been observed by the late Professor Robison, that the comparison of the Chevalier Dubuat's calculations with his experiments is in all respects extremely satisfactory; that it exhibits a beautiful specimen of the means of expressing the general result of an extensive series of observations in an analytical formula, and that it docs honour to the penetra- tion, skill, and address of Mr. Dubuat, and of Mr. de St. Honore, who assisted him in the construction of his ex- pressions. 1 am by no means disposed to dissent from this encomium; and I ai^ree with Professor Robison, and with all other late authors on hydraulics, in applauding the un- usually accurate coincidence between these theorems and the experiments from which thev were deduced. But I have already taken the liberty of remarking, in my lecture on the history of hydraulics, that the form of these expiessions is by no means so convenient for practice as it might have Been rendered; and they are also liable to still greater ob- jections in particular cases, since, when the pipe is cither extremely narrow, or extremely long, they become com- pletely erroneous : for notwithstanding Mr. Dubuat seems to be of opinion, that a canal may have a finite inclination, and yet the water contained in it may remain perfectly at rest, and that no force can be sufficient to make water (low in any finite quantity through a tube less than one twenty- fifth of an inch in diameter; it can scarcely require an ar- gument to showj that he is mistaken in both t[iese respects. 2 It
Hydraulic Investigations. \ 25
It was therefore necessary for my purpose to substitute, for the formulae of Mr. Dubuat, others of a totally different nature; and I could follow Dubuat in nothing but in his general mode of considering a part of the pressure, or of the height of a given reservoir, as employed in overcoming the friction of the pipe through which the water flows out of it; a principle, which, if not of his original invention, was certainly first reduced by him into a practical form. By comparing the experiments, which he has collected, with some of Gerstner's, and some of my own, I have ultimately discovered a formula, which appears to agree fully as welL as Dubuat's with the experiments from which his rules were deduced, which accords better with Gerstner's experiments, which extends to all the extreme cases with equal accuracy, which seems to represent more simply the actual operation of the forces concerned, and which is direct in its applica- tion to practice, without the necessity of any successive ap- proximations.
I began by examining the velocities of the water discharged through pipes of a given diameter with different degrees of pressure; and I found, that the friction could not be repre- sented by any single power of the velocity, although it fre- quently approached to the proportion of that power of which the exponent is 1*8 5 but that it appeared to consist of two parts, the one varying simply as the velocity, the other as its square. The proportion of these parts to each other must however be considered as different in pipes of different diameters, the first part being less perceptible in very large pipes, or in rivers, but becoming greater than the second in very minute tubes; while the second also becomes greater for each given portion of the internal surface of the pipe, as the diameter is diminished.
If we express, in the first place, ail the measures in French inches, calling the height employed in overcoming the frictionyj the velocity in a second v, the diameter of the
pipe d, and its length /, we may make f~ a-rtf3- -f 2 c :.v j
for it is obvious, that the friction must be directly as the length of the pipe; and since the pressure is proportional
t9
126 tiydraulic Investigations*
to the area of the section, and the surface producing the friction to its circumference or diameter, the relative mag- nitude of the friction must also he inversely as the diameter, or nearly 50, as Dubuat has justly observed. We shall then
find that a must be -boooool A30 i£?2 - l44° - 18° ") >
and c = -0000001 ( ^°°dd +_L /]050 + ^ + -9 )Y
Hence it is easy to calculate the velocity for any given pipe or river, and with any given head of water. For the height required for producing the velocity, independently of friC- tion, is, according to Dubuat,- _, or rather, as tt appears from almost all the experiments which I have compared,
: and the whole heisrht h is therefore equal to /' -f , 550 ?.'• 1 J 55Q
or A =r / -j \i--h --v ; and man in 2; b =
\d 550/ d ' ° al:d+ 00182'
7 •/
and e = - , y* -f 2ey == M, whence v = ^/ (£/z 4- e1)— c* a
In order to adapt this formula to the case of rivers, we
must make I infinite,* then b becomes and hh = — «
al a I
d* .... '
= — -, $ being the sine of the inclination, and d four timer,
the hvdraulic mean depth ; and since e is here = — , v =»
a
?— 1 1—1 x and in most rivers, v becomes nearly
y {20000 ds). f
In order to show the agreement of these formula? with the result of observation, I have extracted, as indiscrimi- nately and impartially as possible, forty of the experiments made and collected by Dubuat ; I have added to these some of Gerstner's, with a few of my own • and I have compared the results of these experiments with Dubuat's calculations, and with my own formula?, in separate columns. There are six of Dubuat's experiments, which he has rejected as irre- gular, apparently without any very sufficient reason, since he has accidentally mentioned, that some of them were made with great care; I have therefore calculated the velocities for thc*e experiments in both ways, and compared the results in a separate table. Tabular
Hydraulic Investigations.
127
Tabular Comparison of Hydraulic Experiments.
|
Observer. |
J |
k elofc. |
r. |
)ub. |
ratio. |
V. |
Cbx. ratio. |
a •17x |
c I'x |
($0000*0 |
|
|
iJl Bl \1. |
SJs |
mp |
0r5S |
077 6 |
n-io |
•0537 |
124 |
952 |
I'M |
||
|
->hx-:> |
64 13 |
SH-7fl |
as-oa :• s |
^76 |
0V.i\ |
28-02 -0221 |
124 |
952 |
26-3 |
||
|
9-2-1 |
•>1827 |
9-61 |
7-01 ? |
81S* |
077: |
8-1 I -06 19 |
115 |
91 1 |
9-3 |
||
|
sr. |
15-fi |
#6*8 |
1-27 |
5-07 ? |
0-55 |
111: |
6-27 |
0923 |
413 |
887 |
7-5 |
|
17-0 |
928S |
5-70 |
5*86 |
V0I20 |
5-sn |
•0-9! |
376 |
165 |
6-1 |
||
|
!(:• |
43V |
m •) a |
n-oi |
01*24 |
30 '67 |
OS5I374 |
451 |
27-6 |
|||
|
11 -7 |
1 -i I ^ |
14-17 |
13*50 |
•0181 |
14-05 |
00B7 1 360 |
1 1 6 |
1-2-2 |
|||
|
g-9 |
4pi |
«2-37 j |
24-37 |
o:nv |
21-41 |
0*9 355 |
1 1 1 |
27-7 |
|||
|
5+ |
q|. |
01-51 ! |
*i-i« |
0051 |
27 -3 ■" |
■Oi)-i: :VH> ! MM, |
23*5 |
||||
|
Observers. |
i. |
J. |
-At t r. |
Dub.;1'';- jra Mo. |
tl |
Log. •atio. |
a Fx |
c |
|||
|
COLPLKT. |
18 |
I3TO |
145-08 3M6 |
ij0;51 1-0148 |
MS- 19 |
0075 |
376 j 469 |
||||
|
5 |
84240 |
25"00 |
5-32 |
5- 29| -0024 |
5\(. |
0065 |
3-26 492 |
||||
|
16-75 |
4-13 |
4-23-0103 |
4*2 j |
6083 |
|||||||
|
9-58 24 |
s-oi |
2«2*j 0190 |
2U)I |
•oooo |
|||||||
|
Bossi r. |
'2-01 |
2160 |
a»43 |
24-08'-01!5 |
2r7r |
0006 |
'287 |
7 17 |
|||
|
12 |
U6-38 |
i (/1 0/007.) i.'i'Si, |
•0 b 5 |
||||||||
|
!0S0 |
24, |
35-77 |
;J.Vlo!-()08-2;.S5-Oa |
008fl |
|||||||
|
860 |
24 |
58*90 |
38-80 *O007 56i8: |
■015-1 |
|||||||
|
L-33 |
2400 |
ID |
I2'5fi |
12-75 0005 13*26 |
•024* |
'270 |
919 |
||||
|
, |
1080 |
24 |
28-08 |
>8-21 -0020I28-84 |
0116 |
||||||
|
360 |
'24 |
4>6S |
49*52 -0Q8S!48;66 |
0015 |
|||||||
|
I- |
600 |
12 1 |
42-28J2l-U8i-00$a tS-2l2|l 1-76:0167 |
$>;83 w-'h |
0!06 •0108 |
'259 |
10^3 |
||||
|
D:;r.i vr. |
•;:;: |
2*7 |
2S-67I-.-9-11 -01 11 |
Mr 1 i |
•Osid |
||||||
|
12-2 |
19-0^ ltt:9a :O0O9|20'67 |
•0145 |
|||||||||
|
<\4 |
10-56 10-66 -0641!10*9t |
01:57 |
■ |
||||||||
|
■ |
m |
5 H6 |
*i-95ls&5!*4oa»|83'h 5S-31 58.474^014 58-41 |
•0009 |
|||||||
|
t |
•00 1\ |
||||||||||
|
•24167 |
1 s«^a |
85'7* 85-20 K0O29I85-7I |
•0003 |
309 |
;2268 |
||||||
|
t |
41*25 |
7:r8i.7:/90': 0OO5J74-67 |
(>05l |
||||||||
|
1 |
1 20.41 |
5 1 -'JiioO- 1 1 • 0 L'k? 50*87 |
0093 |
||||||||
|
5-00 |
f3-40i23-19h003i |
'23-09 |
•005* |
||||||||
|
i |
•K.S |
7-58 s- >-='•» 12< |
) 7-2\- |
•02 b |
|||||||
|
.- lutiT |
| 36->: |
i 54 '25 38-75 |
rf4-37tS4-»5i--P031 6i-0i |
002! ■P05.-J |
402 |
\Ml |
|||||
|
; |
iv 6 |
^88tsS'l7l«0«8»2-6" |
|||||||||
|
-•o. |
0-6-2 1 10-49[-005.'l 9-;. |
■060 |
|||||||||
|
yvib |
'M-r |
•!2-l7 |
■; f64-2i <OW0]45-A |
1 518 |
'3! 05 |
||||||
|
i |
i |
! SSfrft) |
4 i-6i i H-7 ii-ooi0 4 ;•;>;, |
i-(joot |
|||||||
|
' 14*58 |
26-20 25-52 ;0U « >4-9 |
1 |
|||||||||
|
j 2-0^ |
7 '321 8-331-b572l 0-9; |
I |
|||||||||
|
(Mean -0!7& i M>eai |
lO.W |
J |
|||||||||
|
L. |
I 042 |
i. |
lf04 |
-'. |
GeRS.TNERj
125
Hydraulic Investigations.
|
Observers. |
tf. |
r. |
ft. |
j'. |
Dub. |
I.O<*. nit. |
Y. |
Log. rat. |
a. |
c. |
|
(jCRSTVEP |
||||||||||
|
at 55 5° F. |
■i |
63 |
107 |
24*2 |
23 9 |
006 |
24-1 |
002 |
349 |
2533 |
|
7-7 |
21 0 |
19-9 |
023 |
19-1 |
"042 |
|||||
|
4-7 |
158 |
14 9 |
026 |
13-9 |
•056 |
|||||
|
11 |
7-5 |
8* |
080 |
6-9 |
•036 |
|||||
|
•7 |
2-5 |
5'0 |
•301 |
3-1 |
•133 |
|||||
|
■VSA |
33 |
107 |
27-1 |
23-4 |
•06] |
2^-5 |
•081 |
488 |
3259 |
|
|
7-7 |
2»€ |
tf-4 |
•077 |
18-5 |
•098 |
|||||
|
•1-7 |
15 -4 |
14'9 |
021 |
13-5 |
•058 |
|||||
|
1-7 |
56 |
8'l |
160 |
6-7 |
•078 |
|||||
|
•7 |
*a |
4-6 |
•801 |
3-4 |
•169 |
|||||
|
•0674 |
33 |
10-7 |
100 |
8-9 |
031 |
10-j |
•004 |
975 |
5700 |
|
|
' """" T" | |
7-7 |
f* |
7'- |
r0J2 |
8-2 |
•057 |
||||
|
4-7 |
4-5 |
56 |
095 |
5-6 |
095 |
|||||
|
1-7 |
1 5 |
S'l |
316 |
»fi |
•222 |
|||||
|
•7 |
•5 |
l-fc |
•444 |
ll |
•342 |
(Mean •129 = L.1*346-09» = L. 1-254)
Y. at 60°.
|
H |
8-50 |
32-4 |
14-40 |
0 |
CO |
13-36 |
•032 |
2956 |
|
i |
9'49 |
30-0 |
•53 |
•52 |
•008 |
13404 |
||
|
1 17 |
5-8 |
•27 |
•30 |
•046 |
DlHlAT.
|
(Mean 029- |
=L. 1-0 |
|||||||
|
s |
255-25 |
46-35 |
86-31 |
B4-2 |
•011 |
79'7 |
035 |
287 |
|
1 |
24 |
16 25 |
t22!59 |
117 -8 |
•018 |
1208 |
•007 |
259 |
|
±1 |
106-45 |
I01-J |
•02* |
L04J |
010 |
|||
|
18 |
84^85 |
82*S |
'Ots |
84-8 |
000 |
|||
|
9 |
59-25 |
57*5 |
•01' |
59-7 |
•004 |
|||
|
4 |
n-oi |
1 18-67 |
1115 |
'02; |
118-5 |
•000 |
1388? 452100
747 1063
(Mean -017 = L.1 -041 -009 = L. 1-022
Tt appears from thi> comparison, that in the forty experi- ments extracted from the collection, which served as a basis lor Dubuat's calculations, the mean error of his formula is ^T of the whole velocity, and that of mine ^j- only ; but if we omit the four experiments, in which the superficial ve- locity only of a river was observed, and in which I have calculated the mean velocity by Dubuat's rules, the mean error of the remaining 36 is --$-, according to my mode of calculation, and -JT according to Mr. Dubuat's ,• so that, on the whole, the accuracy of the two formulae may be con- sidered as precisely ecjual with respect to these experiments. In the six experiments which Dubuat has wholly rejected,
the
tjydraulic Investigations. \q$
the mean error of his formula is about -5V, and that of mine Vt» In fifteen of Gerstner's experiments, the mean error of Dubuat's rule is one third, that of mine one fourih; and in the three experiments which I made with very fine tubes, the error of my own rules is one fifteenth of the whole, while in such cases Dubuat's formulae completely fail. I have determined the mean error by adding together the lo- garithmic ratios of all the results, and dividing the sum by the number of experiments. It would be useless to seek for a much greater degree of accuracy, unless it were probable, that the errors of the experiments themselves were less than those of the calculations ; but if a sufficient number of ex- tremely accurate and frequently repeated experiments could be obtained, it would be very possible to adapt my formula still more correctly to their results.
In order to facilitate the computation, I have made a table of the coefficients a and c for the different values of dt wk the measures being still expressed in French inches*
Table of Coefficients for French Inches.
|
d |
a •V x |
C •1' X |
d |
a •V x |
c r x |
d |
a •V x |
c •i" x |
|
00 |
430 |
900 |
15 |
370 |
427 |
'7 |
249 |
1278 |
|
500 |
427 |
943 |
10 |
354 |
414 |
•6 |
248 |
1384 |
|
400 |
426 |
946 |
9 |
350 |
421 |
•5 |
249 |
1524 |
|
300 |
423 |
950 |
8 |
345 |
433 |
•4 |
257 |
1717 |
|
200 |
421 |
951 |
7 |
340 |
440 |
i |
268 |
1895 |
|
100 |
416 |
923 |
6 |
335 |
462 |
•3 |
279 |
2008 |
|
90 |
415 |
911 |
5 |
325 |
512 |
i T |
303 |
2225 |
|
80 |
413 |
896 |
4 |
319 |
540 |
•2 |
349 |
2532 |
|
70 |
410 |
872 |
3 |
305 |
617 |
i 7T |
402 |
2827 |
|
CO |
408 |
840 |
2*5 |
296 |
687 |
•15 |
440 |
3026 |
|
50 |
406 |
792 |
2 |
288 |
751 |
i T |
458 |
3116 |
|
40 |
400 |
719 |
1-5 |
275 |
866 |
r |
518 |
3405 |
|
30 |
393 |
618 |
1 |
259 |
1063 |
7 |
589 |
3693 |
|
25 |
387 |
560 |
•9 |
255 |
1123 |
•1 |
646 |
3985 |
|
20 |
380 |
492 |
•8 |
252 |
1193 1 |
For example, in the last experiment, where d is 1, / 4, and h 27 1, we have a = -0000259, h
Vol. 33. No, 130. Feb, 1809.
«/ : d f QQ182
516,
120 Hydraulic Investigations,
,5 1 6, c :=> '0001063, e^= td : rf =. '22, and v = ^ (M + e1) — c =3 1 18-46, which agrees with the experiment within -^ of the whole. I had at iirst employed for a the formula
430 5Jf l
; , , ,. — , -f r -f ,. ,,» but I found that the value, thus 1 -f- i 2 : d a orid r{
determined, became to lien d was about 20, and too
small in some other eaSes. Coulomb's experiments on the friction of fluids, made by means of the torsion of wires, give about *00014 for the value of c, which agrees as nearly with this table, as any constant number could be expected to do. I have however reason to think, from some experi- ments communicated to me by Mr. Robertson Buchanan, that the value of a, for pipes about half an inch in diameter, is somewhat too small ; my mode of calculation, as well as Dubuat's, giving too great a velocity in such cases.
If any person should be desirous of making use of Du- buafs formula, it would still be a great convenience to be- gin by determining v according to this method; then, tak- ing b = , ^_ -a m ? or rather, as Langsdorf makes it, l —
. '. jfr/lftjfr to proceed in calculating v by the formula v
I \ T?| • ( V l - H.L. S {b + V6) ~ •00')' this determination of b will, in general, be far more
accurate than the simple expression b = -, , and the
continued repetition of the calculation, with approximate values of v, may thus be avoided. Sometimes, indeed, the values of v found by this repetition will constitute a diverg- ing! instead of a converging series, and in such cases we cm only employ a conjectural value of v, intermediate be- tween the two preceding ones.
Wiving' sufficiently examined the accuracy of my for- mula, I shall now reduce it into English inches, and shall add a second table of the. coefficients, for assisting the cal- culation. In this case, a becomes '0000001 (413 + ~r .—
1410 180 \ / gOOdd 1 — - ), c — '0000001 ( -~ ^ 4- — r
4 x. 12 S d + -J55/5 \dd + 113(5^ ^ d
(1085
131
, e being
Hydraulic Investigations.
13"2l 1-0563 x . , 1
(1083 +. _ + __), and b = ^-^-^^
&c/ • ■-'{ , .ds cc. c
-j-, a«d^, V (M + f>«-*J or t= ^(fl+ fla)- ->
as before; and in either case the superficial velocity of a ri- ver may be found, very nearly, by adding to the mean ve- locity* v its square root, and the velocity at the bottom by subtracting it.
Talk of Coefficients, for English Inches,
|
d |
a |
c |
d |
a |
c , |
d |
a |
c |
|
■V xj |
1 |
-V x |
*17 X |
'V x |
•ll x |
|||
|
00 |
413 |
900 1 |
15 |
354 |
430 ; |
;7 |
243 |
1322 |
|
500 |
"410 |
944 |
10 |
339 |
413 |
•6 |
243 |
1433 |
|
400 |
409 |
948 |
9 |
336 |
421 i |
•5 |
245 |
1578 |
|
300 |
406 |
951 |
8 |
331 |
433 |
•4 |
254 |
1779 |
|
200 |
404 |
951 |
7 |
327 |
449 j |
1 r |
268 |
J 963 |
|
100 |
3199 |
918 |
6 |
322 |
471 ! |
•3 |
280 |
2082 |
|
90 |
398 |
903 |
5 |
312 |
507 ! |
1 ' 4 |
305 |
2307 |
|
80 |
396 |
885 |
4 |
306 |
5 56 \ |
•2 |
354 |
2631 |
|
70 |
3-93 |
860 |
3 |
292 |
635 ! |
1 "0" |
409 |
2943 |
|
60 |
391 |
825 |
2-5 |
284 |
694 |
•15 |
447 |
3150 |
|
50 |
369 |
772 |
2 |
277 |
774 |
1 T |
466 |
3251 |
|
40 |
383 |
698 |
1-5 |
266 |
894 |
T |
528 |
3558 |
|
30 |
377 |
597 |
1 |
251 |
1-099 , |
1 y |
599 |
3866 |
|
25 |
371 |
526 |
•9 |
248 |
1161 |
•1 |
657 |
4183 |
|
20 |
1 364 |
482 |
•8 |
245 |
1234 |
II. Of the Resistance occasioned by Flexure in Pipes or Rivers*
Mr. Dubuat has made some experiments on the effect of the flexure of a pipe in retarding the motion of the water flowing through it; but they do not appear to be by any means sufficient to authorise the conclusions which he has drawn from them. He directs the squares of the sines of the angles of flexure to be collected into one sum, which, being multiplied by a certain constant coefficient, and by the square of the velocity, is to show the height required for overcoming the resistance. It is, however, easy to see, that such a rule must be fundamentally erroneous, and its coin-
I 2 cidence
132 Hydraulic Investigations.
cidence with some experiments merely accidental, since the results afforded by it must vary according to the method of stating the problem, which is entirely arbitrary. Thus it depended only on Mr. Dubuat to consider a pipe bent to an angle of 144° as consisting of a single flexure, as composed of two flexures of 72° each, or of a much greater number of smaller flexures ; although the result of the experiment would only agree with the arbitrary division into two parts, which he has adopted. This difficulty is attached to every mode of computing the effect either from the squares of the sines or from the sines themselves -, and the only way of avoiding it is to attend merely to the angle of flexure as ex- pressed in degrees. It is natural to suppose, that the effect of the curvature must increase, as the curvature itself in- creases, and that the retardation must be inversely propor- tional to the radius of curvature, or very nearly so ; and this supposition is sufficiently confirmed by the experiments which Mr. Dubuat has employed in support of a theory so different. It might be expected, that an equal curvature would create a greater resistance in a larger pipe than in a smaller, since the inequality in the motions of the different parts of the fluid is greater ; but this circumstance does not seem to have influenced the results of the experiments made with pipes of an inch and of two inches diameter : there must also -be some deviation from the general law in cases of rery small pipes having a great curvature, but this deviation cannot be determined without further experiments. Of the 25 which Dubuat has made, he has rejected ten as irregular, because they do not agree with his theory ; indeed four of them, which were made with a much shorter pipe than the rest, differ so manifestly from them, that they cannot be reconciled : but five others agree sufficiently, as well as all the rest, with the theory which I have here proposed, sup- posing the resistance to be as the angular flexure, and to in- crease besides almost in the same proportion as the radius of curvature diminishes, but more nearly as that power of the radius of which the index is f, Thus if p be the number of degrees subtended at the centre of flexure, and q the radius of curvature of the axis of the pipe in French inches, we
shall
Hydraulic Investigations.
133
shall have r = ^5557 nearly, or, more accurately, r =
•0000045 pv* q\ ■ . .
. 1 hcsc calculations are compared with the
whole of Dubuat's experiments in the following table.
Table of Experiments on the Resistance occasioned by Flexure.
|
p |
(1 |
V* |
r |
B. |
Y. 1 |
Y.2 |
|
288 |
3-22 |
15030 |
4-75 |
6-71 |
6-98 |
|
|
11330 |
3-50 |
5-06 |
5-26 |
|||
|
7199 |
2-33 |
3-21 |
3-34 |
|||
|
3510 |
1-08 |
1-56 |
1-62 |
|||
|
216 |
7216 |
2-19 |
2-49 |
2-42 |
2-52 |
|
|
111. |
1-50 |
1-66 |
1-61 |
1-67 |
||
|
72 |
•75 |
•83 |
•80 |
•83 |
||
|
196*5 |
6-12 |
1-50 |
1-66 |
we |
1-31 |
|
|
I47.4 |
1-12 |
1-24 |
•87 |
•9S |
||
|
98-3 |
•75 |
•83 |
•58 |
'65 |
||
|
49-1 |
■"• |
•37 |
•41 |
•29 |
'33 |
|
|
112*5 |
•53 |
6-00 |
7-68 |
6'36 |
||
|
99 |
5-90 |
6-74 |
5-60 |
|||
|
• 2S8 |
3*22 |
3415 |
1-50 |
1-55 |
1-52 |
1-58 |
|
2S8 |
3-22 |
3415 |
1-50 |
1-57 |
1-52 |
1-58 |
|
144 |
*75 |
•78 |
•76 |
•79 |
||
|
72 |
•37 |
•39 |
•38 |
•39 |
||
|
196-5 |
6 12 |
•7.5 |
•78 |
'55 |
•62 |
|
|
112-5 |
•53 |
1-50 |
3-63 |
3-00 |
||
|
720 |
3-22 |
5125 |
5-90 |
5-90 |
5-72 |
5-95 |
|
288 |
3458 |
1-64 |
1-59 |
1-5* |
1-60 |
|
|
860 |
•41 |
•40 |
•38 |
•40 |
||
|
_« |
821 |
•39 |
•38 |
•37 |
•38 |
|
|
28S |
4-10 |
3448 |
1-33 |
1-21 |
1-30 |
|
|
7449 |
2-90 |
2-59 |
2-78 |
|||
|
294-8 |
9-91 |
|||||
|
360 |
41 £ |
8-64 |
8-08 |
8-63 |
||
|
112-5 |
I'll |
In the last three experiments, the diameter of the pipe
was two inches. The radius of curvature is not ascertained
within the tenth of an inch, as Dubuat has not mentioned
the thickness of the pipes. The mean error of his formula
in fifteen experiments, and of mine in twenty, is -~T of the
whole.
[To be continued.]
13
XXI. Ana-
[ 134 ]
XXI. Analysis of the Schist that accompanies the Menilite near Paris . By Professor La m p a d i u s *•
JL he schist that accompanies the menilite near Paris was formerly confounded with poUersckiefer , or polishing slate: but Werner has given it the name of klebschiefer, or adhe? sive slate, on account of its property of adhering strongly to the tongue. After his return from JVance he gave me some of it for the purpose of chemical analysis.
Werner gives the following as its external characters : It adheres strongly to the tongue— colour, pale yellowish gray-- without lustre — fracture slaty in even laminae — opake-- takes a slight degree of lustre by scratching — is very tender — separates into, leaves spontaneously, which is one of its principal characters — specific gravity under 0*2.
It serves as a gangue to the menilite, with which it is found in the hill of Menil-Montant near Paris. — The fol- lowing are the results of my chemical experiments on it.
a. Roasted for two hours in a powerful wind furnace, it lost 30 per cent, of its weight. Its colour became a deep brown. It exhibited no signs of fusion, either .in a clay crucible, or in a crucible lined with charcoal : yet it had become harder and less friable. That which had been roast- ed in the clay crucible was rendered very attractable by the magnet.
b. Exposed to the blowpipe on charcoal and with oxygen gas, it melted in a few seconds into an opake glassy bead, of a blackish brown colour.
c.N Exposed to the flame of the blowpipe simply, it was r\ot possible to melt it : but with borax a small portion was, dissolved, and coloured of a blackish brown.
These preliminary trials, and its effervescence with mu- riatic acid, led me to suspect that it contained carbonic acid and iron.
d. A thousand parts of the mineral distilled in a retort yielded 270 of carbon cacti.
e. Another thousand parts dissolved in ten times their, weight of muriatic acid lost 270 parts.
* Extracted from Beytrage zur Enveilcrung dcr Chernie, 1804.
It
Analysis of adhesive Slate. 135
It contains therefore 27 per cent, of carbonic acid. The' analysis was conducted in the following manner :
1. One part of the mineral in fine powder was put inlo four parts of concentrated sulphuric acid, in which it dis- solved with evident effervescence j and the solution was evaporated to drvness.
2. The residuum was diffused in water, and a gelatinous matter separated, which was still a little yellowish. This was silex.
3. The liquor was filtered,
4. The gelatinous residuum was washed with boiling water, till no further trace of sulphuric acid was discoverable.
5. This water and the filtered liquor were evaporated to- gether, till there remained but ten drachms.
6. Some sulphate of lime separated, which was decom-t posed by an alkaline carbonate; and after it had been heated and roasted 0*08 of pure lime were obtained.
7. The liquor separated from the sulphate of lime being concentrated by heat, yielded crystals of sulphate of iron and of sulphate of magnesia.
8. T put the whole, without separating the crystals, into a platina crucible, and exposed the saline mass to a strong heat for two hours. ^
9. After cooling, the mass had an ochrey colour, and a bitter taste. On it I affused boiling water, filtered and washed the residuum.
10. The oxide of iron remained on the filter. After hav- ing been dried and roasted it weighed 0*09.
11. I added to the liquor carbonate of ammonia, when a white earth was precipitated, which, dried and roasted, ap- peared to be magnesia, and weighed 0.28.
12. The yellowish gelatinous residuum (No. 4) was di- gested in muriatic acid, till its colour became entirely white.
13. Being filtered and washed, the liquor was of the co- lour of pale white wine. Being precipitated with ammonia. I obtained some more oxide of iron, which, washed and roasted, weighed 0*03.
}4. Having redissolved this oxide of iron, and that of No. 10, there yet remained 0*008 of silex.
I 4 15. The
136 Analysis of some Steatites.
15. The residuum of No. 13 was found to be pure silex,
which, after having been dried and roasted, weighed 0*30. 100 parts of this mineral therefore contain
Magnesia 28
Carbonic acid 27
Silex 30-8
Oxide of iron 11*2
Lime 08
Water 0*3
98-1 Loss 1*9
100
The most remarkable circumstance is, that this mineral .contains no alumine, and includes a large quantity of iron. The outward appearance of the mass would lead us to susr pect the former substance, and its light colour by no means indicates so large a quantity of the second. Probably the carbonic acid combining with the oxide of iron conceals its presence.
M. Klaproth, who had before analysed a specimen of this schist, found in it :
Silex ....66*5
Alumine 7
Magnesia 1*5
Lime 1*2.5
Oxide of iron 2-5
Water 19
♦ 97*75 Loss 2*25
100
XXII. Comparative Analysis of some Varieties of Steatite , or Talc. By M. yAuaup;LiN*,
JL he smoothness and unctuosity of the stones called stea- tites has been commonly ascribed to the presence of mag-
* From Annates de Chimie, tome xlix.
nesia,
Analysis of some Steatites. 137
nesia, this earth having been found in all of them that have been analysed 5 and in consequence all stones possessing these external characters have been classed together. But the pierre de lard, or speckstein, which in some respect may be considered as the prototype of the species, having been analysed by Klaproth, and no magnesia found in it, has changed the opinions of mineralogists on this subject, and led them to wish that some of these substances should be analysed anew. * j
To remove this uncertainty, M. Haiiy gave me three va- rieties of talc, that 1 might make a comparative analysis of them.- — The first of these is termed in Haiiy's -Mineralogy laminar talc. It is of a greenish white colour when seen ia the mass, very smooth to the touch, and divides into ex- ceedingly thin flexible laminae of a silvery white. — The second is called in the same work talc glaphique, because it is employed in sculpture; but commonly pierre de JarJ. It is the bildstein of the Germans. This is compact, very greasy to the touch, and of a colour varying between gray, yellowish, and greenish. Its fracture is dull, uneven, and at the same time scaly. — Of this species M. Hatiy sent me two specimens ; one of a yellowish white, from a broken Chinese image ; and the other of a light rose colour, but in every other respect perfectly similar to the preceding speci- men.
Analysis of Flexible Laminar Talc.
1. One hundred parts of this stone, calcined in a strong fire, acquired a vellow colour, with a light rosy tint, was deprived of its flexibility, and lost six parts of its weight. Its laminae being thus rendered very fragile, I could easily reduce it to powder.
2. The hundred parts thus calcined I heated with twice their weight of caustic potash. The mixture did not melt ; but its tumefaction indicated, that a combination between the substances had taken plaee.
3. The mixture diluted with water was afterwards dis- solved in muriatic acid, and evaporated to dryness in a gen- tle heat. Towards the end of the operation the liquor formed f jelly.
3, 4. The
338 Analysis of some Steatites.
4.. The residuum, being lixiviated with* distilled water, left a white powder, which, when calcined in a red heat, weighed 64 parts. It was pure silex.
5. Ammonia, mixed with the liquor separated from the silex, formed in it a yellow precipitate of little bulk, from which 1*5 of aluminc were separated by means of caustic potash. The remainder was oxide of iron, weighing 3 parts and a half.
6. Having precipitated the iron and alumine by means of ammonia, I put into the liquor a 'solution of carbonate of soda, and set it to boil. As soon as the mixture began to grow hot, it grew turbid and deposited a large quantity of a white powder, which, when washed and calcined, weighed £7 parts. This substance was magnesia, for with sulphuric acid it formed a salt that had all the characteristics of com- mon sulphate of magnesia.
flexible laminar talc therefore is compounded of
Silex 62
Magnesia 27
Oxide of iron 3*5
Alumine 1*5
Water 6
100
From the smallness of the quantity of the iron and alu- mine, I think these substances maybe presumed not to be essential to the formation of the stone ; so that perfectly pure laminar talc may be deemed a compound of silex and magnesia.
Analysis of compact rose-coloured Talc. In the analysis of this variety T pursued the same pro- cesses as in that of the preceding; I therefore need not enter into the particulars. The following are its results :
Silex 64
Magnesia 22
Alumine 3
Iron mixed with magnesia ... 5
Water 6
100
Analysis
Analysis of some Steatites, 139
Analysis of the yellowish compact Talc (Speckste'm).
1. A hundred parts of this stone strongly calcined lost 5 parts.
2. Heated afterwards with twice its weight of. potash in a silver crucible no fusion took place, but the matter was? greatly increased in bulk, and had become homogeneous.
3. This was diffused in water, and dissolved in muriatic ^cid. The solution, being evaporated, became gelatinous, towards the end of the operation.
4. The matter being dried and washed, a white powder remained, which, after calcination, weighed 56 parts.
5. The silex having been separated by lixiviation, the liquor was mixed with a small quantity of muriatic acid, and ammonia was afterward poured in, which formed in it a copious white flocculent precipitate.
6. The liquor being filtered, the precipitate was washed and dried. This was alumine, and weighed 30 parts. The alumine dissolved entirely in sulphuric acid, and its solu- tion, saturated with the requisite quantity of potash, af- forded very pure alum : but the mother water, evaporated afresh, yielded 5i: parts of sulphate of lime crystallized in needles. Thus with the assistance of the alumine the am- monia precipitated the lime from its solution in muriatic acid.
7.. The liquor from which the alumine had been sepa- rated gave^io precipitate with carbonate of soda, even assisted by long boiling. The speckstein therefore contains no mag- nesia, like the two preceding varieties. — But in recapitulat- ing the products of this analysis we find only 93 parts; namely,
Silex - ' , 56
, Alumine 29
Lime ...... 2
Iron 1
Water 5
93
A loss so considerable, which is not common in such analyses carefully executed, led me to suspect that the compact talc contained some other principle, which the
processes
140 Analysis of some Steatites. >
processes employed did not enable me to discover. In con- sequence I treated a hundred parts, reduced to fine powder, with concentrated sulphuric acid.
I« After boiling for two hours I dried the mixture, lixi- viated the residuum with distilled water, and boiled the lixivium. At the expiration of a few days I obtained 36 parts of alum crystallized in cubes : and by a second evapo- ration I procured from the mother water 15 parts more of the same salt mixed with a few needly crystals of sulphate of lime.
2. The stone appearing to me to be but imperfectly decom- posed, I powdered it afresh, and treated it as before. On adding the acid employed in this operation to the mother water of the preceding, I obtained 15 parts more of alum, making in all 60 parts. Then, as I employed for this ope- ration very pure sulphuric acid, and added no potash to the solution, it is evident that the stone contained a certain portion of this alkali, and that this substance was the occa- sion of the loss I had in the first analysis. Sixty parts of alum, however, do not require seven of potash, the quantity of loss, but as the stone is very siliceous, it is probable that the whole of the potash was not extracted bv the sul- phuric acid, though I boiled the stone twice in it.
The speekstein therefore is composed of
Silex 56
Alumine 29
Lime 2
Jron 1
Water 5
Potash 7
100
In his analysis of speekstein, M. Klaproth found no potash : but the quantity of water, which, according to him, amounts to 10 per cent., and the loss of 2}, which he ex- perienced, will just balance the deficiency I found. It is probable that M. Klaproth estimated the water by compu- tation, and not by direct experiment ; for, to whatever heat I exposed the stone, it never lost more than 5 per cent.
From
Analysis of some Steatites. 141
From this analysis it follows, that of the three varieties of talc here mentioned, two only must continue to be so called ; namely, the laminar talc, and the compact rose-co- loured talc. The third, the speckstein, should be removed to the genus of alkaliniferous stones.
It deserves particular remark, that those two varieties, which most resemble each other, and which have always been classed together, should now be separated by analysis : which shows, that minerals should never be classed accord- ing to their external appearance, since the most striking analogies in this respect are the most deceitful. In fact, the speckstein and compact rose-coloured talc have the same softness, the same fineness of particles, the same fracture, nearly the same specific gravity ; and certainly, if there were any room to suppose that one of the three substances ought to be separated from the" talc species, we should be more inclined to suppose it the laminar, than either of the others.
Note. I analysed at the same time that species of talc known by the name of crate de Briangon, or French chalk, and I found it to contain the same principles, and nearly in the same proportions, as the laminar talc, and the compact rose-coloured talc. These proportions were,
Silex 61-25
Magnesia 26*25
Water 6
Alumine 1
Oxide of iron 1
Lime 0*75
Loss 3*75
100
XXIII. Me-
[ H2 ]
X^IIF. Memoir upon the Vineyards and Wines of Chairi- pagnein France: Written in answer to certain Queries cir- culated by M. Chaptal. By M. Germon, of Epernay.
[Continued from p. 85.]
XXIII. What is the Method of operating in the Press, id order to make While" IV'uieP
J. Hfc press being previously well washed and cleaned, and the screw inspected and greased, the fruit is pressed by three successive and rapid turns of the screw in certain districts, and by two only in others, according to the expe- rience of the proprietor, the strength of his machinery, and -the expert nes 8 of his workmen, or the nature of. his grapes* The whole of this operation should be finished in less than an hour by good workmen. Before applying the press, three or four layers of billets or pieces of wood arc thrown upon the grapes, placed in such a way as to make the pressure ge- neral. After allowing thejuice to flow for about five minutes, the press is slackened, in order to stir up the remaining mass, and clear away any obstructions, and the operation is jepeated.
The wine flows through a hole into a small tub, called a carbou, placed under the press.
When the three pressures have been effected, the wine produced from thejuice is called vin d 'elite, or choice wine* It is called in the language of the workmen vin de cuevec, or wine of the tub ; but of this expression I highly disapprove, as it gives an idea to strangers that the white wine of Cham* pagne is allowed to ferment (cuver) in tubs.
This vin d* elite is carried from the carbon into a tub ad- joining, in which it is allowed to deposit its lees and all other heterogeneous matters during the night : this tub is called the cuve de depot.
After this vin d 'elite is extracted, there still remains some juice in the husks of the grapes : a new turn therefore is given to the screw of the press, and the wine issues through a hole placed a little lower in the press into another tub :
thii
On the Vineyards and Wines of Champagne. 14$
this juice is called the first cut. {premiere laille), and fre- quently enters into the composition of the vin d' elite. If the wine is not already too villous, the juice from this last pressure is allowed to flow for about an hour, according to the season or other circumstances. ' /
Another pressure is still given at a subsequent period, and the wine is called deuxieme taille, or vin de tisanne, so much called for at certain seasons.
A third pressure h sometimes given at another interval, and the wine is muddy, hard, and vinous.
Lastly, a poorer kind of wine, cailed vin de rebechage, is produced by repeatedly pressing the husks until they are perfectly dry : these operations are also called drying the husks.
The vin d' 'elite, after having been allowed to remain all night in the tub, where it deposits its sediment, &c, is put into new or well rinsed puncheons, and the juice from the subsequent pressures is successively treated in the same
way.
XXIV, What Use is made of the Wines last drawn off, which are generally very spirituous ; hut which, being co- loured, cannot be mixed with the first Juices ?
As it has been experienced that the Champagne wines of the last pressures, notwithstanding their vinositv, are too weak, and would occasion too much waste of time and ex- pense to distil them into brandy, it is found more advan- tageous to sell them in the vineyards of inferior qualitv, in order to improve the poorer kinds of wine : they are "Some- times sold also to inn-keepers, after a sufficient quantity has been retained for the use of the domestics of the pro- prietor.
In some places, however, these wines arc distilled ; but it requires from five to eight pieces of them to make one piece of brandy.
[Articles 24, 85, ;S6, 27, and 28, regard the making of red wine, and will be treated of under a separate head.]
1
XXIX. How
144 Memoir on the Vineyards and Wines
XXIX. How is Red Wine made?
The grapes for making red wine are managed with the same precautions as those for white wine.
The only difference consists in loosely depositing the grapes Tor making red wine in vessels for the purpose: these vessels are covered, and their contents are allowed to remain until the first fermentation has begun in the colouring pelli- cle of the iruit.
This must, in a state of fermentation, is deposited under the press : the same turns of the screw are given as to the white grapes.
XXX. How are the White Wines managed until they are
jit for drinking P The white wine, when left in the state described at the end of No. XXII., enters into fermentation, at first ra- pidly, and afterwards in a milder manner: when it has gone through all these degrees of fermentation it becomes clear; and when the weather is dry with a clear frost it is racked off", being previously fined with a proper quantity of isinglass. With one pound of Marseilles isinglass forty pieces of wine are fined.
XXXI. What is the Process of clarifying White Wines ;
and at what Age are they bottled P The isinglass is prepared by breaking it, in order to divide it into small pieces : it is then diluted in some wine drawn from the puncheon. When both are well mixed up to- gether, it is introduced into the bung-hole of the cask, its contents being briskly agitated with a staff or other instru- ment: the wine is then allowed to rest: it undergoes another slight fermentation, until the coldness of the weather finally settles it.
One month or six weeks afterwards it is again racked off; and a slight proportion of isinglass is added, to bring it to a state of perfect limpidity.
XXXII. At what Period is it bottled P In the month of March these wines are generally bottled.
XXXIIL How
of Champagne in France, 145
XX 'XII L How is the Operation of Bottling performed P
The wine is drawn off into bottles well chosen, well rinsed, and of an approved manufacture: they are corked with the very best kind of corks .-.pieces of thread or iron wire are used for fixing down the corks firmly; the bottles are then put into the collar, and piled up on their sides.
Trie elaboration of the juice not being completed when the wiue is bottled, a slight fermentation takes place in the bottles. About the middle of August in the same year this fermentation begins, and frequently there is a loss by the end or September of five or ten per cent, from the bottles breaking. This loss sometimes goes on increasing until next year, according as the wines are more or less juicy or vinous.
XXXIV. Is it necessary to cover the Corks with Wax P
It is not necessary to wax the corks when the wine is bottled : this expense would be thrown away ; since about 15 or 18 months after being bottled, when the wine has ex- hausted all its fermenting principles, and is to be sold and sent off, it must be again disturbed, in order to undergo the operations pointed out in No. 38. This moving of the wine consists of making a slight deposit disappear, which, notwithstanding the first clarification, is indispensable jn the different operations necessary : Secondly, such bottles must be filled up as have leaked or lost by filtration through the corks, and the broken bottles are also to be removed.
XXXV. IV hat are the Faults to which W lute IV hies are subject, either in Casks or Bottles P
The faults to which white wines are most liable are mud- diness (lagraisse), acidity, and sometimes also yellowness of colour. White wine very rarely becomes muddy when in the casks ; but this happens sometimes with bottled wines.
The wine is said to be greasy {gras) when it is milky and whitish, and when it does not sparkle and present bubbles on its surface when hastily poured out.
When it is ascertained that this accident has happened, care must be taken not to disturb the wine, and the disease
Vol. 33. No. 1*0. Feb. 180W. K genera!]}-
1 1 Iti Memoir en the Fineijards^tnd IVines
general'!) cures il self, by the next or following spring. The whitish. sediment turns brown, and deposits or attaches itself to the bottle; and the wine becomes once more diaphanous and sparkling.
XX XVI . IF hat are the Means used to remedy this P
When the s'eacs6ri has been rainy, the vintage wet, and the juice is too watery, this disease is very frequent; and
-;dcs, if the white is in more abundance than the red fruit, the yellow disease is mixed with what is called the greasy, and in this case it is no longer fit for sale : it has a disagreeable teste, and is of the colour of cider : nothing can be done with it, unless it is mixed with common or inferior red wines.
Greasy wines must be cured by time alone; and they very rarely continue more than a year in this state.
All the preservatives recommended in books upon this subject are of no avail : when employed, they are found to injure the quality of the wine instead of improving it.
Ntitei Acidity being more peculiar to red wines, it will be treated of under that head.
XXXVII. Hon- docs it happen that Half of the Bottles are
broken during the first Six Months P The breaking of the bottles is owing to several causes more or less direct and more or less well ascertained.
It depends in the first place upon the choice and quality of the wine; the time at which it is put into bottles; the quality of the glass ; the nature of the cellar; the tempera- lute of the weather, and even on the wav in which the bot- tles are packed. We cannot therefore assign the exact cause of this accident, so much connected with the phamomena of nature: in general, however, when a proprietor has no mors than twenty bottles broken in one hundred he does not com- plain.
XXXVIII. When WMlif IVines deposit a Sediment in. BotildS\ n-lr.'f are the Methods of extracting this, Sedi- ment before sending thkm off, to their Place (f Destination P Liie sediment in white wines, when they are not spoiled
.'#u other respects, u made to disappear in the following way :
4* . » If
of Champagne in Prance, 147
If the wine is not muddy the operation is very simple : %it consists in emptying the bottle witheare, keeping it in the precise direction in which it lay : the workman with a small hook removes the iron wire which fixes the cork ; he then uncorks the bottle, and presents in a perpendicular direction another bottle to it quite empty and well rinsed, and pours out all the wine, leaving the sediment, which, if the bottle has not been shaken, will remain at the bottom*
Some persons make use of a syphon, when the wifie is not thick, in order to avoid all shaking.
When the wine is thick the operation is more tedious and more delicate : wooden planks are made use of, in which holes are made at proper distances, in order to receive the bottles : these planks being arranged, adjoining to the col- lection of bottles, an intelligent and experienced work- man carefully takes a bottle from the heap, keeping it in the same position in which it lay : he then gives it a slight shake, and by a regular and long- continued movement he brings into the side, of the bottle the sediment which is de- tached, and, without scattering it through the liquor, makes it slowly descend to the neck : he then places his bottle upon the plank which lies ready to his hand, inclining it in a sloping direction : he afterwards does the same by a second, a third bottle, &c, which he places in the same. sloping direction.
Four-and-twenty hours afterwards the workman returns to the plank where he has deposited his bottles ; he once more ^ives them a slight shake, and slopes them a little more, in order to bring the sediment nearer to the cork : it* i he sediment has then completely fallen down, and the wine ft limpid, the workman holds the bottle perpendicularly ele- vated, and does the same with all the rest of the bottles placed upon the planks : he returns with -his hook, uncorks the bottles, and with a dexterous motion of the wrUt turns them upside down : the fixed air escapes and pushes out the sediment, which falls into a receiver: the workman then dexterously replaces the bottle upon its end, after allowing nothing to escape, except what is necessary to render it lim-
K <2 pid.
148 Memoir on the Vineyards and Wines
pid. Another workman then fills it up with good wine, re,r corks it, and the wine is fit for sale.
By this delicate and cautious operation, the wine loses nothing of its briskness, but occasions a great expense in utensils, fresh corks, wire, labour, &c. It has become necessary, however, of late, since the consumption of Cham- pagne has become so general throughout Europe, and great exertions are made to keep up its celebrity.
XXXIX. Do the sparkling Wines keep well f The wines of Champagne, after being put into circulation, and having travelled about, preserve their good qualities for ten years : but when they are kept in cellars, and particu- larly in those of-Champagne, which are superior from the nature of the soil (being dug out of beds of chalk), they will keep for twenty and thirty years.
XL. What Degree of Temperature is best adapted for the
Preservation of Wines P — Point it out with reference to
Reaumur's Thermometer.
I am well convinced that it is by always preserving an equal temperature that the breaking of the bottles may be avoided when in the cellar. Currents of air passing through the cellars should by all means be prevented: but in order to establish an equal current of air, the cellars should be dug very deep : they, however, would be so expensive that few proprietors could be prevailed on to adopt such a regulation. At Rheims, Ay, Hautvillers, Epernay, Cramant, and Vertus, there are, I have seen, some cellars made upon a most ex- cellent plan, and where no expense has been spared.
I have never tried the temperature of the air of the cellars, and I cannot give any results upon this head.
[Articles 41, 42, 43, 44, and 45, being entirely applicable to the management of wines, will form part of a particular treatise upon the subject of red wines.]
XLVI. What is the Price of an Acre of the lest Vineyard Ground? (The acre being 100 rods and 22 feet.)
lavres. At Ay - - - i. 6000
Hautvillers-
« of Champagne in France. I, H9
Livres.
Haulvillers ... 3000
Epernay, Pierry, Avise, Cramant 3000 Other vineyards - 2000
XLVIT. What does an Acre of the second Quality cost P
At Ay - 3000
Hautvillers ... 2500
Epernay, Pierry, Avise, Cramant fOOO
And the other vineyards - 1000
XLVIII. W hat is the Expense of the annual Culture of an Acre of Vineyard) including the Expense of Prunings and of Vintage P
Livres.
The ordinary expense of cutting, hoeing, tying, and
pruning the vines - - - 80
Expense of occasionally propping up such vines as have
fallen, &c. - - - 60
16 or 18 bundles of props, 50 in each bundle - 30
Dung and carriage of the vines, &c. - - 42
Five empty puncheons for each acre's produce, at
ten livres - - - - 50
Expense of gathering, pressing, keeping the labourers,
&c. &c. ----- 46
303
Produce of an Acre of Vineyard.
It is generally understood, that, taking the average often vintages, five pieces or puncheons of wine are obtained from every acre.
Three of these are of the first quality, or choice wines: and two of them are ordinary wines.
The three puncheons of best wine may be valued at
150 livres each - 450
The two others at 50 - - - - 100
First result - - 550
From which we must deduct the expense of bottling and of cooperage at "ten livres for each piece of the
K 3 best
Livres.
15.0 Memoir on the Vineyards and f Vines of Champagne,
Livres.
best wine. The fining of these wines being iftost
expensive - - * - r «- 30
For the two other pieces three livres only - 6
Annual interest of the money laid out for the
ground, &c. - - - - 100
Taxes, &c. 72
Labour, &c., as above » • - 308
516
First resujt - r - r r 550
From which deduct as above - - r 516
Net produce of an acre of vineyard in middling years 34 We may easily perceive that the net produce cannot b£ estimated upon very just and rigorous data, as the wines of Ay, Hautvillers, Epernay, and Pierry, fetch from 200 to 400 livres each piece ; and a mean price must be fixed for all the other classes of Champagne wines, which sell for 00 up to 200 livres.
It follows from this statement, that, without great indus- try, a proprietor can derive but a small profit, who is obliged to sell annually in the cask the produce of his vines ; the rich proprietor only, who can afford to put his wines into bottles, and keep them for two or three years, can depend upon a certain and real profit.
In what Manner is the Vine planted in the Mountain P The vines are planted differently m the mountain and on the banks of the river. The greater part of the vine-growers, who have contracted habits which they will not give up, notwithstanding the inconveniences which they are every day aware of, plant their vines in March only : the shoots they use are either produced from the tall vines which have keen beaten, and which have very few roots, or from other plants which spring up among the low vines at the moment of cutting the vines, and which have also very few roots, since they are procured from stalks that have lain on the ground since the commencement of the season.
[To be continued.]
XXIV: Me-
[ 151 J
XXIV. Method of painting Linen Cloth in Oil Colours, to le more pliant, durable, and longer impervious to Water, than in the usual Mode. By Mr. William Anderson, of His Majesty's Dock-Yard, Portsmouth*.
Sill,
1 beg leave to lay before the Society of Arts, &c., the fol- lowing improvements and observations, whioh I hope will be of service to the public.
Having never heard or read of any method being disco- vered to prevent paint when laid on canvass from hardening to^sueh a degree as to crack and eventually to break the canvass, and render it unserviceable in a short time; and having been an eye-witness for many years of much canvass perishing for want of such discovery, in the immense quan- tities painted for covering seamen's hammocks, and for other uses on board his majesty's ships ; I long had it under con- sideration to find out such an ingredient as, when mixed with paint, would preserve the canvass and paint laid thereon from the damages above mentioned : and after experiments for a considerable time, I have discovered such an article, and made trial of it with effect above three years.
The canvass I have painted has been submitted to the in- spection of the Navy Board, who are so perfectly satisfied with my new method, that general directions are now given to paint all canvass in his majesty's dock-yards in this man- ner; which, in addition to the advantages I have before men- tioned, actually saves an expense of one guinea in every hundred square yards of canvass so painted, as I have fully stated to them. The ingredient I use is not only serviceable for ships' canvass, but also for canvass designed for paintings, for floor-cloths, and for painted coverings within and with- out doors. I have no doubt of it being applied to many other purposes 1 am yet unacquainted with ; as, from actual trials of near four years, I can vouch for its being a prcscr-
* From Transactions of the Society for the Encouragement o/V/r/.s, Manufac- tures, ami Commerce, for 1807. The silver medal of the Society was voteq
to Mr. Anderson for this communication.
K 4 vative
152 On painting Linen Cloth in Oil Colour w.
vative to red, yeiiow, and black paints, when ground in oil and put in casks. When the oaints were examined at the expiration of such time, they discovered no improper hard- ness; but when laid on the work with a brush, il\ey dried in a remarkable manner, without the addition of any or the usual drying articles. I still preserve some of these paints for future trials, and I believe this plan of preserving co- lours will be of essential use to colourmen, and other per- sons who purchase colours for exportation. The ingredient I use is perfectly simple, being a solution of yellow soap ; and the composition for painting is made in the following manner :
To one pound of soap I add six pints of water in a vessel over the fire ; in a few minutes after the boiling of the water the soap will dissolve ; whilst hot it is to be mixed with oil paint, prepared as hereafter directed, and is then fit for im- mediate use. The above quantity of soap solution will be sufficient to mix with one hundred weight of paint. The first coat to be laid upon the canvass is to be entirely of this composition, without first wetting the canvass in the usual way. A very small proportion of it, or none, is necessary in the second coat ; and the third coat should be of oil paint alone.
4 The method heretofore practised in his majesty's dock- yards for painting canvass, was as follows : The canvass was first wet with water, then primed with Spanish brown ; a second coat given it of a chocolate colour, made from Spanish brown and black paint ; and, lastly, finished with black. This mode is destructive, and more expensive than mine in the proportion before mentioned. In my method, to ninety-six pounds of English ochre ground in boiled oilj I add sixteen pounds of black paint, being one-sixth in pro- portion of the ochre; this, when mixed, forms an indif- ferent black. The solution, made of one pound of soap and six pints of water, is to he added to this paint, and well united therewith ; and will, out the canvass being previously wet, this composition is to be laid upon the canvass as stiff as can conveniently be done with the brush, and this first coat will form a tolerably smooth surface. The second coat «5v i ;. is
On painting Linen Cloth in Oil Colours, 3
is to be formed of the same proportion of English ochre an J black, without any soap solution ; and the third or finishing coat, to be done with black paint as usual.
I am, sif, your obedient humble servant,
Wm. Anderson,
• Master Painter of H. M. Dock- Yard Portsea, Oct. SI, 1806. at Portsmouth.
SIR,
A.GREFARLY to the request in your letter, I have enclosed certificates relative to my new method of painting canvass; and I take the liberty of informing you of a method of ob- taining from painted canvass, unserviceable, the whole of the colour laid thereon, and to do it at a very small expense. This J discovered since T last wrote to you, and I believe it will be of considerable advantage to government, who, for want of such a thought, have buried and burnt immense quantities of ships' hammock cloths, when found unser- viceable, to prevent embezzlement from taking place. I suggested the idea to N. Diddems, esq., builder of Ports- mouth yard, who communicated it to the honourable George Grey, commissioner. I obtained leave to make an experi- ment, which I repeated thrice, and found that from one ton of painted canvass, unserviceable, I obtained, upon an average, four hundred weight of dry colour, in value to government nine pounds six shillings ; the expense of the process not exceeding six shillings.
This I effected by calcination, raking aside the ashes and sprinkling them with water, to prevent loss of paint through excess of heat. By passing the calcined matter through a line sieve, it is perfectly prepared i >r grinding j it grind* well, possesses a good body 1 >r covterii j* wHh£ and dries well with a good gloss. Its increase ot btiik, in comparison with common colour of equal weight, gives it the advantage of covering more work. The colours yi<- Jed by the calci- nation or di Herein coloured canvass are as follow : viz. Can- vass which has been painted with black paiut only, produce* a black colour. Canvass finished black, but which has had a previous red or yellow ground, will produce a dark cho*
colate
] M On painting Linen Cloth in Oil Colours.
colate colour. Canvass painted lead-colour will yield a good dark lead-colour.
1 am, sir, your obedient humble servant,
Wm. Anderson.
Portsca, March 25, 1807.
To C. Taylor, M.D. See.
Certificates, dated March, ISO?, were received from the following persons, viz.
A. Stow, lieutenant and commander of the gun -brig Steady, stating, that in the preceding month of October he had received on board his ship a set of hammock cloths, painted after the method invented by Mr. William Ander- son, which had been constantly in use since the time above mentioned, and appeared fully to answer the end proposed, of rendering the canvass soft and pliable, of preventing its cracking, or the paint peeling off, and which in the old method had been a subject of much complaint.
John Pridy, lieutenant and commander of the Gladiator, and formerly commander of the Dapper, on which latter ship a set of hammock cloths, painted after Mr. Anderson's method, appeared fully to answer the end proposed.
P. F. Wyatt, oil- and colour-man, Portsea, stating that lie had seen canvass painted after Mr. Anderson's new me- thod, which, after a trial of sixteen months, remained per- fectly soft and pliable, the paint by no means cracking or peeling oil", and that the gloss was retained, though it had been exposed to all weathers. He further added, that he had seen the paint prepared by him from old painted canvass found unserviceable, and had worked and painted there- with; that it was, in his judgment, very good, and would answer either on canvass, wood, or iron.
Ns. Diddems, master shipwright, Portsmouth dock- yard, stating, that Mr. Anderson had proposed to him to obtain, by calcination, from old unserviceable painted can- vass, the paint which had been laid thereon ; that such ex- periment was made, and four hundred weight of dry ser- viceable paint prepared from one ton of such canvass ; that
he
On painting Linen Cloth in Oil Colours. 155
he had seen it when ground /in oil and laid on work, when it appeared to possess all the properties of goad paint, and bad therefore been recommended by him to the Navy Board.
SIR,
In answer to your letter of the 23th of April, in whieh you informed me that the eommittce were desirous that I should furnish them with a sample of canvass painted in the old method, and another on my improved plan, I trust that I shall be able fully to comply with their request. In the first place, I have sent a small sample of the residuum of the burnt canvass, fit for grinding in oil for paint, also ax piece of- canvass painted therewith, marked No. 1 ; another piece painted after the old method, marked No. 2 ; another piece painted according to my process, marked No. 3 ; and, lastly, a piece finished entirely with a new composition, marked No. 4 ; each sample having received three coats of paint. Upon examining No. 2, you will find it becoming ' from time to time more stubborn, in consequence of the paint hardening ; and when a small ridge is formed in it, by press- ing it between the finger and thumb, it will soon discover that it is subject to crack, and by this means, permitting the wet to enter it, will soon rot the canvass.
The space of time proper between laying on the new pre- paration and the second coat, ought to be one entire day; but if saving time is an object, the second coat may be put on (he day following the first ; fora if the canvass is placed in an advantageous situation for drying, the composition will dry or harden so as not to rub ofT.
Canvass finished entirely with the composition, leaving it to dry one day between each coat, will not stick together if laid in quantities, as you will find by making experiments on the sample No. 4.
Since the Navy Board have given directions for ships' can- vass to be painted according to my method, I find, upon calculation, that I have painted upwards of twenty thousand yards since November last, a great part of which has not been hung up tor painting and drying more than one week,
as
1.56 On painting Linen Cloth in Oil Colours,
as no more time could be allowed me, in consequence of ships sailing. Mv plan was therefore to lay on the compo- sition the first day, to coat it the second day, and, leaving one intermediate day, to finish it on the fourth. Three days were then allowed it to dry and harden ; and when after- wards taken down and folded together in cloths, containing sixty or seventy yards, they did not stick together.
Having no means of giving information to persons con- cerned in grinding colours, so well as through the medium of the Society of Arts, &c. I beg leave further to relate how I have, for the last three years, saved the labour of three men out of four in grinding colours with the common mill* employed for that purpose. One mill has ever been con- sidered sufficient for a man to turn, whereas one man can now, with perfect ease, turn four mills ; this is effected by placing two mills on each side of the winch, so close as only to leave room for the fly wheel to play between them. The spindles of each on either side are locked together by a small iron collar, with a pin passing through it. The distance of the mills thus paired from each other, in order for the man's standing between them to turn, is two feet six inches. The distance of the arms of the winch screwed on the end of the spindles on either side, is two feet two inches; the length of the arm is one foot six inches from the spindles to the bar across which the man clasps in order to turn.
Fly wheels at the extremity are impediments. Necessity was ttuly the mother of invention to me in this case, as I had great demand for paint, and I was not allowed men sufficient for the work in the common way.
Persons will scarcely believe, without seeing the experi- ment, the ease with which they turn. If a little extraordinary motion is first given them, and they are then left alone, they will continue to go round sixteen times ; so that a man with one hand may turn them.
I am, sir, your obedient humble servant,
Wm. Anderson.
Portsea, May 6, 1807.
To C. Taylob, M.D. Sec.
SIB,
Experiments on various Earths. 157
SIR,
I have stated to the Admiralty Board the several im-. provements made by me in paint work ; and in consequence thereof they have desired the principal officers of our yard to report to them on their merits. The officers, who have for more, than twelve months past daily had the execution of them under their inspection, have recommended the same in stronger terms, and the advantages thereof, to the lords commissioners, beyond my statement. I have enclosed to you a certificate relative to the ship Hibernia, which arrived here the 12th of May last, and for which vessel I painted a set of hammock cloths, containing thirteen hundred yards of canvass, in June 1806, after my new method. I am, sir, your obedient humble servant,
Wm. Anderson.
Portsmouth, Nov. 27, 1807.
To C.Taylor, M.D. Sec.
XXV. Experiments on various Earths, undertaken with the View of ascertaining whether they are metallic Oxides. By David Mushet, Esq.
J. he late interesting experiments of Mr. Davy in metallizing soda and potash, have brought to my recollection a tram of experiments in which 1 was engaged eight years ago, with a view to metallize some of the earths. Though considerably disappointed in my first attempts, yet I have repeatedly re- turned to the charge with increased hopes, but without ob- taining any thing like a perfect result.
In giving to the public a detail of my experiments, it is impossible that I should mean to bring them forward with any view to a comparison with the perfectly original and satisfactory results of Mr. Davy. Our modes of operating were so totally different,- that similar results could not be expected. Should, however, any beneficial or useful pur- pose arise from the knowledge of the new metals ; then, so far as a simple mode of operation goes, my reasonings and practice may be of service to others who may engage in a similar undertaking.
My
153 . Experiments on various Earths.
My first experiments were made with pure earths, clay, silex, lime, barytes, and strontian, considering them as metallic oxides, whose oxygen might be carried off by pre- senting them with carbon at a high temperature, and secured from the access of air. This reasoning I carried into prac- tice by cementation for hours, and sometimes for three or four days. Various earths were exposed imbedded in finely- pounded charcoal. These were afterwards freed from the carbonaceous matter, and exposed to fusion in high heats in a wind furnace. Clay and silex I found infusible under the highest heat that could be urged. Barytes, lime, and strontian, were fused with various proportions of charcoal, but no result occurred from which any conclusion could be drawn favourable to the idea of either a part, or the whole, of the oxvgen having been removed from the respective earths, nor was it found that any loss of weight took place, (as is the case with iron ores,) which would not have oc- curred by simply exposing these substances to the same temperature. The glasses resulting from the different fu- sions were various in colour, whitish, opaque, brownish, and black. The only circumstance which indicated change was in the barytes, the different fusions of which always gave a thin pellicle on the surface that never was resolved to glass, but was alwavs strongly alkaline. This, at the time, I could not account for, nor tii! Mr. Davy's discoveries were announced. The probability then appeared, that this was a portion of the barvtium, which, during the operation, had been metaibzed, but, in cooling, had again attracted oxygen from the atmospheric air, and had passed into the state of an alkaline earth.
After many experiments, I at that time abandoned the pursuit, and arranged those specimens of glass which ap- peared most fit lor future examination, should the subject present itself under any new shape. Some years afterwards having occasion otherwise to examine the boxes in which these .specimens were kept, I was much surprised to find, that nianv of the glasses had become converted into a fui<; powder, [was induced, from a similar circumstance hav- ing liken place with a gUfig of manganese, to infer* that in
the
Experiments on various Eartlis, 15Q
the original experiment a de-oxidation had taken place, and that by the reassumption of oxygen the present effect had been produced.
I then thought of pursuing some mode of operation which would enable me to detect what proportions of oxygen were united to the various earths. This I thought of accom- plishing by a set of comparative experiments in the fusing of pure malleable iron with the different earths. Iron being a highly oxidable metal, the quantities disappearing would indicate the comparative quantities of oxygen in each of the earths. This was with a view to form the most ample data for subsequent experiments, and to compare the alkalis with alkaline earths. These experiments embraced a number of substances, as will be brought forward in the t'tMail.
T, — 200 grains of calcareous earth (very pure Paris white), deprived of its carbonic acid, were mixed with 50 grains of iron filings : these were mixed together and exposed to a high decree of heat ; a perfect fusion of the earth had taken place, which was now converted into a black glass of a deep jetty lustre. Two small but finely polished spherules of metal were obtained weighing 12 grains — loss by oxidation 38 grains, or 76* per cent. It may be proper to state here, that SO grains of malleable iron filings, ihe same used in this and the following experiments, were fused for ie in ten minutes, and the button formed in consequence weighed 4 7' grains— loss onlv 74- percent. — oxidation in consequence of the calcareous earth nearly 70 per cent. more.
f J.— 100 grains of pure barytes and .50 grains of ri}ini>s of. malleable iron were fused together. - A black brownish opaque irlass was obtained, and beneath a smooth-skinned metallic spherule was found weighingl)' grains — loss 40 1 grains— equal to 81 per cent. L'mrn the portion of the earth to the iron in this experiment being double, in place of quadruple, as in cite last experiment, it was inferred that 100 q rains of calcareous earth would oxidate 19 grains of irotf, whereas 100 grains of 'barytes in Una experiment oxidated 41 j grains.
III.— 100
160 Experiments on various Earths.
III. — 100 grai i carbonate of barytes in a similar ex- periment ' 'at« . only 41 \ grains of iron *,
IV. — 100 grains of carbonate of strontian deprived of its carbonic acid oxidated 21 j grains of iron.
V. — 100 grains Q,f,potash oxidated 28 grains of iron.
VI.— 100 grains of salt of tartar oxidated 22 grains of iron.
VII. — 100 grains of calcined borax oxidated 3} grains of iron, i
VIII. — 100 grains of window glass, composed of two parts of soda and two of Lynn-sand, oxidated 4^ grains.
IX. — 100 grains of bottle glass oxidated 3 grains of iron.
X, — lOOgrains of roasted ironstone, containing iron 48*5 '> oxygen 15-5; earths 36* — 100, oxidated 33 grains.
XI. — 100 grains of manganese in a similar experiment oxidated 25 1 grains.
It appeared from these experiments, that either barytes contained the greatest dose of the oxidable principle, or that it gave it out to iron with the greatest facility. It was there- fore fixed upon as the most proper subject for further expe- riment, the details of which I shall state as shortly as pos- sible.
XII.--^100 grains of pure barytes were exposed to a heat of 168° jrf Wedgwood. An emerald-coloured glass was obtained, which, in cooling, arranged itself into numerous small squares; the surface was covered with a crust or pel- licle very like an oxide of nickel.
XIII. — 100 grains of barytes mixed with 10 grains of charcoal were exposed to the same heat. The result was a dark- green glass, accompanied with a similar saline crust, rather more of a coppery colour. The charcoal had disap- peared .
XIV. — The same experiment was repeated with 20 grains of charcoal. The fusion, though exposed to as high a heat, was less perfect. A greater quantity of the apparent oxide V*as formed, and a proportionably less quantity of glass.
* The result of this experiment being the same as Experiment II., Mr. M. has probablv made a mistake in copying his notes. — Edit.
2 XV.— This
Experiments on various Earths, 161
XV; — This- experiment was performed with 100 grains of pure barytes, 200 grains of iron-stone, and 8 grains of charcoal.
The reasoning which suggested the use of iron-stone pro- ceeded Upon the supposition that the surface incrustation was an oxide of barytes (barytium), effected to a certain stage of purity, in consequence of fusing pure barytes with charcoal. It seemed probable that the addition of a second affinity would, with the acid of the charcoal, tend to remove the more fixed and ultimate portions of oxygen over which the charcoal had no power. It was conceived that the iron- stone, not being saturated with oxygen, might withdraw a portion of that supposed to exist in the partially revived ba- rytes, and tend to metallize the result. Malleable iron* as in the other experiments, might have been used; but as this would always have entailed the presence of a button of iron, the result, it was supposed, would be attended with some uncertainty. In the present experiment it was thought proper to reduce the quantity of charcoal to eight grains, lest any part of the iron contained in the oxide might thereby be revived.
This experiment being exposed to a similar heat as the others, a flat blackish mass was obtained weighing 270 grains — loss of weight in the whole 38 grains. The iron- stone alone ought to have lost 70 grains. It was therefore inferred, that some new combination had taken place, and what in other experiments would have been volatilized, in this, became fixed. When the mass was divided, it exhi- bited an uncommon appearance : the surface was covered with a black de-vitrified glass ; the fracture showed a beau- tiful metallic crystallization and brilliancy, with some large metallic plates not unlike carburet of iron. Toward the lower edges of the button the crystallization was very per- fect. Although this mass had all the beauty and splendour of a metallic regulus, yet there was a great deficiency of metalline property : it was eagerly brittle, and easily reduced to a powder ; exhibited little or no lustre in grain, or when scratched with a knife point. This experiment was repeated
Vol. 33. No. 130. Feb. 1809. I* under
Utt Experiments on various Earths.
under various temperatures, but without being more suc- cessful in producing the melal in a state of greater purity.
XVI. — 100 giains of pure baryes, 200 of iron-stone, and 10 of charcoal, fused together, gave the following result : Surface a black shining class of considerable thickness, co- veririg a perfect crystallize J regtdus of the same matter as was found in Experiment XV. The same want of metallic property was evident in this as in the last, though the spe- cific gravity of the mass was very much increased. On one side (and not under the imperfect regulus of barytium) was found a metallic spherule, supposed to be revived by the addition of the two grains of charcoal — it weighed 1 \ grain.
XVII.~ 100 grains of pure barytes, 200 of iron-stone, and 13 \ of charcoal, gave a result similar to the former in point of glass. A smaller and more perfect^ regulus- was found under it, alongside of which, as in the former, was found a metallic spherule of iron weighing 10 grains.
XVIII. — 1(0 grains of pure barytes, with 200 of iron- stone, and 20 of charcoal. The result of the fusion of tint compound presented something different from any of the former. A button of iron was found weighing 33 grains ; this was surmounted by a black glass, which now con- tained no barytium. Over this glass, and immediately on the surface, a metallic crust presented itself. Tt was cry- stallized in small concentric radii inclining to a brownish silvery colour, and brightened a little under the file. It had, in every respect, a more metalline appearance, and, so far as polish, continuity of grain and lustre were concerned, was much superior to any of the former results.
The same experiment was repealed again and again sometimes with increased doses of iron-stone and charcoal but none of the results were more perfect than the present Despairing, therefore, of any thing more perfect with iron oxide and charcoal, it was resolved to try the effect of mal feable iron tilings in place of iron oxide. Having used all the pure barytes in my possession, the following experi- ments were made with a fine crystallized specimen of car- bonate of barytes.
XIX. 115
Experiments on various Earths. 163 /
XIX. — 115 grains of this carbonate were exposed for two hours to a high red heat, and came out unchanged, both as to weight and appearance.
XX. — 40 grains pounded small were exposed to a high white heat in a Cornwall clay crucible. A rough whitish mass was obtained, which evidently had been fused — weight 36 grains. Loss 4 grains, supposed to be carbonic acid. It was remarkable that the present result in cooling under- went several shades of colour chiefly metallic ; a green suc- ceeded by a vivid purple was the most decided.
XX 1.-^-90 grains of this same carbonate, pounded small, and 45 grains of iron filings were mixed together and fused: the upper surface of the result was covered with a brownish silvcrv enamel regularly, crystallized in small stars, each radi- ating from a common centre. The thickness of this me- tallic crust was nearly one-sixteenth of an inch. Its frac- ture presented brilliant crystallized facets of a highly metal- lic appearance. Under the barytium was found a jet black shining glass, in which was inserted a smooth button of iron weighing 20 grains. Beneath this button was another layer of barytium regularly crystallized, but of a less metallic ap- pearance than the upper stratum. In this experiment 90 grains of carbonate of barytes had furnished the means of oxidating 25 grains of iron.
XXII.-^O grains of carbonate of barytes, and an equal quantity of iron filings, gave by fusion a double stratum of barytium. Interposed between was a layer of black glass; the crystallization and brilliancy of the upper stratum and the general appearance of the whole were very similar to the last experiment. The button of iron found in this result weighed 33 grains. Loss 17 grains oxidated by 50 grains of carbonate of barytes.
This experiment was repeated with various proportions of the carbonate of barytes and the iron, and with greater quantities of matter, yet none of them were so perfect as those detailed in the foregoing experiments. Greater quan- tities of the apparent regulus were obtained, all tending to the same crystalline arrangement, but inferior in point of colour and brilliancy.
L 2 I next
164 Experiments on various Earths.
I next varied the experiments in the following manner: Iron ore was de-oxygenated almost to a state of metallic pu- rity. The ore in this state consisted of 90 parts of iron, with which a little oxygen was si ill combined, and 10 parts of calcareous earth.
XXTII. — 280 grains of this ore, and 2S0 grains of carbo- nate of barytes were fused together, and the result was as foK lows: A double stratum of the reguline matter was formed; the upper evidently more metallic than that below ; yet the general appearance of this was less metallic than the results of Exper. XXI and XX [I. The button of iron was covered on its surface with a silvery- white circle delicately crystal- lized in the starry form peculiar to the barytium ; and this being the first crystallization of that form I had ever seen cni iron, I was led to infer that an alloy had taken place be- tween the iron and the metal of the barytes. The, weight of this button was found to be 172 grains. Loss lOS^rains of matter, which, taken at the rate of 90 per cent, of metal in the ore, gives the quantity of iron oxidated by 280 grains of barytes 97TV grains, or 34-/V grains of iron from 100 grains of carbonate of barytes, a result but little different from the last experiment. |
Similar experiments were performed with various propor* tions of the barytes and de-oxygenated ore; and correspond- ing results were obtained. When the iron existed in equal portions to the barytes, a quantity of crystallized regulus was obtained nearly equal to one half of the result — the other half being always a blaek glass. When a greater pro- portion of iron filings was used, and' to the extent of two parts to one of the barytes, a greater proportion^ the re- gulus was obtained ; but then the experiment was difficult to manage, from the great heat necessary to fuse so large a re- lative proportion of malleable iron, without destroying the barytes altogether. On the contrary, when the carbonate of barytes or pure barytes were used to the extent of two parts to one of iron filings or oxidated iron, the mass was chiefly resolved into a glass, and the greatest part of the iron was oxidated : the quantity of regulus small, and a perfect re- sult always precarious, from the violent action of the barytes
upon
Experiments on various Earths. f 165
upon the clay of the crucible. In this respect barytes re- sembles some rich oxides of iron, which are totally uncon- fi nable in a clay crucible at a high temperature.
After' making two hundred experiments without having obtained, what I thought, a perfect globule or regulus of pure metal, I abandoned the subject till new reasonings and after-reflection should point out any new tract which was likely to lead to more success. I was satisfied that I had obtained an approach to metal, and was even convinced that the metal at one part of the operation was more decidedly so than it afterwards appeared to be when examined cold : but I was not at all satisfied that the regulus I had obtained was in its ultimate state of purity.
Disappointed in my hopes of success with barytes, my experiments on lime and strontian were few; but limited as they were, I was convinced that thev were similar com- pounds, and capable of decomposition. I did not succeed in obtaining so compact reguli as with the barytes, but both of them showed metallic crystallization upon the surface,, although apparently more volatile and destructible than those of barytes.
Should I at any future time increase my experiments on these substances, and should the results point to any thing new and likely to be beneficial, I shall communicate them. I am confident that an increased knowledge on the subject of lime- stone will prove highly interesting to the manufac- turer of iron. The single circumstance of its being a me- tallic substance combined with oxygen, and as such acting its part in the operations of the smelting furnace, will enable him to explain facts that cannot be reconciled to any past reasoning or knowledge on the subject.
In regard to silex or clay, considered as metallic oxides, I have been able to ascertain nothing decisive. They seem not (judging from the experiments I have made) in the most distant manner allied to the other three earths, though thev may be more akin to each other. It is possible that silex may prove to be clay completely deprived (or nearly so) of all its moisture. Or, in other words, that clay, by fire or other natural processes, becomes oxygenated to such an ex-
L 3 tetit
166 Proposal for altering the. Scale of the Thermometer-.
tent as to convert it into what we call silex. May clay not prove to be water and oxygen, and siiex this oxygen with- out water ?
.XXVI. Proposal for altering the Scale of the Thermometer. By Richard Walker, Esq., Oxford.
To Mr. Tilloci-i, — Sir, J. beg leave to announce, through the medium of your useful Miscellany, an intention I have of offering to the public notice an alteration in the scale of the thermometer, which many of my friends, as well as myself, have adopted, from a persuasion of its being founded on the truest principle.
The alteration I shall suggest, and which presented itself during the long course of my thermometrical experiments* I shall only briefly state now, reserving a fuller account of the reasons which induced me to. adopt the scale I now pro- pose to another opportunity.
The two fixt-d points, viz., the freezing and boiling points of water, as they have hitherto been, will probably never fail to be continued, as" being perfectly sufficient for the accurate adjustment of*thermometers.
The commencement of the scale, and the number of di- visions, only appear to claim attention. With respeci to the first, since neither of the extremes of heat or cold (to speak familiarly) are likely to be ascertained, the hope of fixing 0 at either of these may. be entirely relinquished, and it re- mains to fix 0 at the fittest intermediate point.
Hence I presume to propose the following mode of graduation, stating briefly the principle oh which I pro- ceeded. Having ascertained that the temperature of 62° of Fahrenheit is the temperature at which the human body in health is conscious of no inconvenience from heat or cold, and that a deviation from that point of only one or two de- grees, above or below, actually produces that effect, under ordinary circumstances, I fixed my zero or 0 there.
With respect to the divisions, I adopted those of Fah- renheitj from an opinion of that being the fittest, consider-
On the Distillation of recent and of dried Ft get aides. 167 ing those of Reaumur, the centigrades, &c, as being too few, and decimal divisions unnecessary in a thermomctri- cal scale.
Hence it will follow, that 0 being placed at 62° of Fah- renheit, 150° will be the boiling, and minus SO0, the freez- ing points of water ; and all other points on Fahrenheit's scale may be reduced to this, by subtracting 62 for any degree above 0 of Fahrenheit ; and adding 62 for any degree' lelow 0. . -
I shall only add, at present, that there is a very convenient mechanical mode of adjusting this scale in the construction of thermometers. ■. '
For ordinary meteorological purposes, a scale of this kind extending to 65 degrees above 0, and as many degrees below v), will be sufficient.
Rd. Walker.
Queen-Street, Oxford, Feb. 17, 1309.
XXVII. On the Difference between the Products obtained by Distillation of recent and of dried Vegetables t By Mr. Gab den, of Old Compion Street, London *.
X hat most recent vegetable bodies during the process of desiccation undergo a material change in their external ap- pearances becomes evident from mere inspection ; but that an alteration frequently takes place in their physical proper- ties, and also among their constituent principles, by that process, has not-, perhaps, in every case, been so clearly established.
Our knowledge indeed of the physical properties of vege- table substances, obtained from an acquaintance with their chemical composition, has hitherto made but little progress; arising, no doubt, from the exceeding alterability of their nature, when subjected to those processes usually employed for disuniting their component parts ; some of their ingre- dients being too volatile to be retained, while others become so modified by the action of moderate temperature*, as to
* Communicated by Mr, Garden,
L<* / render
J 68 On the Distillation rf recent and of dried Vegetables.
render it difficult to trace the precise order of union which those elements maintained in the original compound. Thus it is found that vegetables, both of the noxious and escu- lent kind, yield by that species of chemical decomposition which is effected by fire, the same common elementary principles; whence it follows, that the precise nature of a vegetable cannot be determined by the mere knowledge of its constituent parts.
When the recent leaves of vegetables are exposed to a de- gree of heat but little exceeding the medium temperature of our climate, an evident change is quickly produced ; their bulk becomes greatly diminished, their colour less vivid; the fragrance, if they possessed any, is in most cases con- siderably impaired, and in some instances totally destroyed ; it will also be found that a considerable loss of weight has been sustained.
These obvious changes may chiefly be referred to the evaporation of aqueous moisture, dissipation of the aroma, and loss of a portion of the volatile or essential oil. That this last effect does not take place is an opinion entertained bv some practical operators, who maintain, that from those vegetables containing essential oil, the greatest quantity may be obtained by previous drying before they are submitted to the process of distillation.
It is not my intention either to combat this opinion or to enter into a detail respecting the chemical composition of vegetable bodies, but simply to state the following fact, which has lately come under my observation.
A quantity of the dried leaves or peppermint (mentha pi- perita), which bad been included in casks well closed for nearly two years, and apparently in a state of good preser- vation, were exposed to distillation, with a view to obtain the essential oil, The operation was conducted in a com- mon still furnished with a connecting refrigeratory, and the products received in an Italian recipient, such as is usually employed for the separation of the lighter essential oils. After a considerable quantity of the fluid had distilled, and that which remained tasted but little of the plant, the pro- cess was discontinued. On examining the receiver, it was
observed,
On the Distillation of recent and of dried Vegetables, 1 69
observed, that the produce of essential oil was excessively small; notwithstanding the quantity of leaves which had been operated upon amounted nearly to 40 pounds.
Apprehending some mismanagement in the operation, another quantity similar to the preceding was introduced into the still : attending at the same time to every circumstance which could possibly be imagined to facilitate the develop- ment of the oil. A piece of basket-work was placed in the bottom of the still, and a quantity of water was added suf- ficient to give fluidity to the mass, and prevent the possi- bility of empyreuma taking place; added to these, the boil- ing point was attended to with care, and the first portions of the distilling liquid were suffered ,only to drop slowly from the condensing vessel.
In this last operation, however, the value of the products did not differ materially from that of the preceding; and the result of several subsequent distillations appeared to show that the essential oil could not be obtained from the dried plant in a proportion equal to that afforded when in a recent state.
In the respective operations it was observed, that although the produce of oil was comparatively inconsiderable, its ab- sence seemed to be balanced by an abundant produce of water highly impregnated, both with the taste and flavour of the plant.
This circumstance appears to warrant the presumption, that the herb, notwithstanding the length of time which it had been enclosed in the casks, had not suffered so much deterioration as the diminished produce of oil might seem to indicate ; for although the essential oil did not appear in an uncombined state, its particles may* have undergone some peculiar modification, in virtue of which it was rendered more soluble, and hence the increased quantity of highly impregnated water may be accounted for.
The addition of alkaline substances in small proportions has been supposed by some to accelerate the evolution of volatile oils from their bases : in the present case this expe- dient was not productive of any remarkable effect.
XXVJTI. Re*
[ 170 ]
XXVII T. Report on a Manuscript IVork of M. Andre, formerly known wider the Name o/*P. Chrysqlogue dk Or, entitled A Theory of the actual Surface of the Earth, By MM, Hauy, Levierre, and Cuvier. Read to the Class of Mathematical and Physical Sciences in the National Institute*.
As this is the first opportunity which has hitherto presented itself of entertaining the class with geological subjects, it will not perhaps be considered foreign to our purpose to make some general reflections on the manner in which a society such as ours may and ou<>ht to consider this kind of researches.
The natural history of unorganized bodies, commonly called crude matter, or minerals, is divided into two principal branches. In the one we examine each of these bodies by itself, and in its physical and chemical properties, and hence determine its distinctive characters, and its rank in the ge- neral system. This part has more particularly retained the name of mineralogy, which has almost always been culti- vated by men of talents, and has now attained a degree of precision and exactness, equal, at least, to that of all the other physical sciences.
The object of the other branch of the history of minerals is the reciprocal position of their different species, and of the masses composed of one or more of these species. It is this branch which teaches us what materials constitute the vast extent of countries, what others are confined to vacan- cies, crevices, and fissures of the preceding; it shows us what substances respectively form the great chains, inferior mountains, ridges, and plains ; it is especially occupied with the super-position of minerals, and enables.us to distinguish between those which always bear,* and those which always surmount others, or, in a word, to discover the order of the different strata. To this branch is given the appellation of geology , geognosy, or physical geography, according to the extent and profundity of the researches. -
It is evidently a science susceptible of as much accuracy as mineralogy properly so called. To give it this quality,
* From Transactions of the Institute, 1808.
it
Report on a Manuscript Wor\ of M. Andrt. 171
it is only necessary to treat it as all the natural sciences ought to be; that is to 9ay, to collect with care the parti- cular facts, and to deduce no general conclusions until these facts are collected in sufficient numbers, observing always tl\e rigid rules or' logic.
It is also evident that this science constitutes a part of na- tural history not less indispenable to the knowledge of the globe than mineralogy itself. It is to the latter, what the history of the climate, soil, and situation proper to each plant is to botany. Its utility to society, if it were once completed,- would be no less evident. By it we direct our» researches for divers minerals, and by the same means an- ticipate the difficulties and expenses attending numerous works, which could not otherwise be known but by expe- rience. Thus, our engineers could not calculate the expense of a subterraneous conduit to substitute for the machine at Marly : geology taught them that at this place they could expect to -find nothing hut chalk.
The miners, who are more interested than any other art- ists to possess this kind of knowledge, have made it a par- ticular study, according to the class of minerals in which they are engaged. They have determined the characters of mountains with metallic veins, and know perfectly the countries where there is nothing to be found, and those where something may be gained. But from the very na- ture of the motives by which they are influenced, they have almost entirely neglected to examine districts poor in metals. It is thus that in our vicinity each workman knows but the kind of quarries in which he works. He who seeks plaister of Paris neither knows what is above nor what is below /the strata of gvpsum : the quarrier is ignorant that under him is potter's clay, &c.
He who is the least acquainted with science, will feel that a study which furnishes ciau with regard to all the useful minerals, similar to those of the miners on metallic veins, must be of the greatest importance to society ; and that were it extended to all the known minerals, it would form an equally agreeable and curious branch of natural philosophv. it is probable that we should have principally studied, with
thii
LfS Report on a Manuscript Work o/M. Andre.
this view, the surface of the globe, and the trifling portion of its interior where we are able to penetrate it, if there had not been found minerals entirely crude. As these mine- rals must have been originally disposed in some order, we should not at first have seen in their disposition proofs of sii cessive action and of revolutions, if a very great part of their beds had not been replete with the remains of orga- nized bodies. The fossils and petrifactions indeed, by ex- citing curiosity and arousing the imagination, have given a too rapid impulse to geology, have raised it too superficially above its first basis, which should be founded on facts, and carried it to search for causes which should have been its final result. In a word, from a science of facts and obser- vations it has changed 'into a tissue of hypotheses and con- jectures, so vain and so contradictory that it is become al- most impossible to pronounce its name without a smile.
At first fossils and petrifications were c6nsidered as lusas nature?, without considering what it really meant. But when a more profound study had shown that their general forms, their texture, and in many cases their chemical composition, were the same as those of analogous parts in living bodies, it became necessary to admit that these objects had also possessed life, and that consequently they had ex- isted at the surface of the earth, or in the waters of the sea. How did they become buried under immense masses of stones and earth ? How were marine bodies transported to the summits of mountains? But above all, How was the order of the climates reversed, so that we find the produc- tions of the torrid zone near the pole ?
When it. was perceived that almost the whole surface of the globe was thus covered, the general and powerful causes which had so dispersed them began to be considered. Ge- nesis, and the traditions of almost all Heathen nations, of- fered one, to which it was natural that philosophers should first have recourse : it was the deluge. The petrifications passed as proofs of it ; and during nearly a century the works on geology consisted either of efforts to find the physical causes of this great catastrophe, or to deduce from it as an effect the actual state of the surface of the globe. Their
authors
Royal Society. 1 73
authors forgot that the deluge is stated in Genesis as a mira- cle, or as an immediate art of the Creator's will, and conse- quently that it is superfluous to seek any secondary causes.
[To be continued.]
XXIX. Proceedings of Learned Societies.
ROYAL SOCIETY.
P ejbruary 2.- — The reading of Mr. Troughton's paper on the Division of Mathematical Instruments by ocular inspec- tion was concluded. One of the methods adopted was the use of a roller one-sixteenth the diameter of the circle to be divided. The description of this principal instrument the author has deferred till a future communication.
A most curious and interesting paper by Mr. Davy was read, giving an account of various experiments on the ac- tion of potassium on ammonia, from which it appears, that a considerable quantity of nitrogen can be made to disap* pear, and can be regenerated. When it disappears, nothing is obtained in its place but oxvgen and hydrogen ; and when k is formed, its elementary matter is furnished by water.
There seem to be, at present, only two modes of ex~ plaining these extraordinary and entirely unlooked-for re- sults : i. e. that nitrogen is either a compound of hydrogen and oxygen, — or, which is the most probable, that hydro- gen, nitrogen, ammonia, water, and the nitrous compound, all contain the same ponderable elementary matter, and that their different forms depend upon different electrical states. The paper concluded by stating that the author was still pur- suing this inquiry, so intimately connected with the whole arrangements of chemistry and meteorolgy.
Feb. 9. — Dr. Young furnished a series of numerical tables of the elective attraction of acids with alkalis, by means of which 100 .figures are made to represent the affinities of 100 different salts, which would otherwise require above 5000 words to express.
Feb. 16. — A paper by Mr. Brodie, describing a twin
foetus,
\ 74 Royal Society .• — Pa tents.
{•'oetus, nearly the full size, seven months old, acid without either heart, liver, or gall-bladder, was read. This was con- sidered ihe best formed foetus which has hitherto been known without a heart, although the author cited a considerable number. It appears that all such children have been twins, and that the present was quite as large as the other foetus which had its organs complete, '
Capt. Burney furnished two papers, one on the motion of heavy bodies in the Thames, detailing some experiments with loaded sticks, to ascertain why loaded barges sailed taster than the current, or than unloaded barges; but his experiments only tended to confirm the tact that the heaviest end of a pole always went first with the current. The other was a plan for measuring a ship's way at sea, by means of a steel-yard and line,' where a pound weight should indicate a mile, or more or less, according to the power of the in- strument.
Feb. 23.— -A letter from Mr. Knight to the President was read, containing some further observations on the sap o{ trees, the formation of radicles from the bark, and also that of the buds from the same source, instead of their being produced from the alburnum, -as supposed.
A paper of Mr. Home's, on a peculiar joint discovered in the squalus maximus (basking shark), lately cast on the sea shore, was laid before the Society, accompanied by a drawing. More interesting particulars respecting the stomaclir of this fish arc to form the subject of another communication.
XXX. List of Patents for New Inventions.
J. o Malcolm Mac Gregor, of Bell-yard, Carey Street, mu- sical instrument maker, and William Mac Farland, of the Strand, umbrella manufacturer, for certain improvements in the construction of umbrellas and parasols. Dec. 29.
To John Bricrley, of River Bank, in the eounty of Flint, for a process of setting blue lead, for corroding the same into white lead. Jan. 17, 1809.
To James Goddart, of Newman Street, gent., for his ma- chinery for manufacturing a certain description of wooden
boxes
List of Patents for Kew Inventions,. 175
Doxes called chip boxes, or pill boxes, of all the various sizes and shapes hitherto made. Jan. 23.
To Edward Straey, of Parliament Street, Westminster* vesq., for an improved method of hanging the bodies, and of constructing the perches of ^four-wheel carriages, by which such carriages are rendered less liable to be over- turned, and of constructing perch bolts and collar braces* Jan. 23.
To John Peek, of Charlotte-Row, Fort Place, Bermond- sey, Surry, millwright, for a machine for casting printing types, by which three motions out of five made in the or- dinary method of casting types are saved. Jan 23.
To Samuel Whitfield, of Church Street, Birmingham, brazier and scale-beam maker, for a method for the appli- cation of stamps, dies, and piercing tools, to the manufac- turing of ears, handles and bewells for culinary articles of every description, whether in wood, iron, brass, copper, tin, silver, or any mixed metals. Jan. 23.
To Michael Logan, of Rotherhuhc, civil engineer, for a transcendant ordnance,- or improved cannon, for either ma- rine, fort, or field service. Jan. 26.
To Anthony George Ecfchardt, of Berwick Street, Soho, for a method of c&sliiTff metallic and other bodies, together or separately, in moulds, in the state of fluidity or softness, in order that the said bodies may preserve the figures thus obtained, when they shall afterwards 'become solid, or con- sistent by cooling, or by any chemical or other change which shall or may take place, or be produced in the nature, order, proportion?, or quantities of the component parts jor ingredients of the same. Jan. 28. \
Theatre of Anatomy, Greville- Street, Hat ton- Garden.
Mr. Taunton's Lectures having been suspended through a severe indisposition, he begs leave to inform his pupils that he intends to resume them on Tuesday next, the 7th instant*
MET.EOJIO'
1 7 6 Meteorology ,
meteorological table,
By Mr. Carey, of the Strand,
For February 1809.
|
| Thermopi |
cter. |
Ke'M'pr of tut Barorm Inches. |
y ■? c ir, ^ 5c |
|||
|
Davs of the Month. |
1 j2 & i y - --* |
^2 — Jc |
Weather. |
|||
|
Jan. 27 |
45° |
51° |
48° |
29*20 |
10 |
Stormy- |
|
, 28 |
49 |
54 |
47 |
'50 |
41 |
Fair |
|
29 |
4 9 |
53 |
45 |
28-98 |
10 |
Storm v |
|
30 |
; 48 |
48 |
44 |
•95 |
0 |
Stormy |
|
31 |
J 37 |
47 |
40 |
29'S5 |
32 |
Fair |
|
Feb. 1 |
46 |
52 |
47 |
•62 |
21 |
Cloudy |
|
2 |
51 |
51 |
48 |
•50 |
25 |
Cloudy |
|
3 |
! 51 |
51 |
46 |
•20 |
24 |
Cloudy |
|
4 |
46 |
49 |
42 |
•45 |
30 |
Fair |
|
5 |
46 |
49 |
44 |
•35 |
15 |
Stormy Cloudv |
|
6 |
45 |
49 |
40 |
•40 |
18 |
|
|
7 |
39 |
39 |
34 |
•90 |
15 |
Cloudy |
|
8 |
33 |
33 |
36 |
•79 |
8 |
Cloudy |
|
9 |
40 |
51 |
47 |
•35 |
7 |
Cloudy |
|
10 |
46 |
53 |
46, |
'16 |
8 |
Showery |
|
11 |
46 |
52 |
47 |
28-75 |
0 |
Rain |
|
12 |
46 |
51 |
45 |
•82 |
9 |
Showery |
|
13 |
46 |
52 |
46 |
•97 |
51 |
Showery |
|
14 |
47 |
51 |
46 |
29*30 |
30 |
Showery |
|
15 |
46 |
52 |
. 44 |
•58 |
0 |
Rain |
|
16 |
45 |
53 |
46 |
•58 |
39 |
Fair |
|
17 |
46 |
54 |
47 |
'69 |
58 |
Fair |
|
18 |
50 |
53 |
44 |
30-34 |
27 |
Cloudy |
|
19 |
37 |
51 |
46 |
•40 |
36 |
Fair |
|
20 |
46 |
52 |
47 |
29-98 |
37 |
Fair |
|
21 |
39 |
42 |
36 |
3005 |
47 |
Fair |
|
22 |
33 |
43 |
41 |
•26 |
4 2 |
Fair |
|
23 |
45 |
52 |
40 |
•12 |
45 |
Fair |
|
24 |
42 i |
47 |
41 |
•30 |
31 |
Fair |
N. B. The Barometer's height is taken at one o'clock.
L 177 3
XXX L Remarks on Hygrometry, and the Hygrometer of J. Birzelius. In a Letter from Mr. J. Gough, to Mr. Til loch.
Middleshaw, Feb. 25, 1809.
X erhaps few additions could be made at present to the ap- paratus of a meteorologist, which would prove more accept- able than a cheap and correct hygrometer. Various attempts have been made to improve the instrument, which have commonly ended in adding to its sensibility : but such con- trivances seem intended to amuse the superficial observer, rather than to assist the lover of meteorology. It is the business of those who cultivate this science, to determine the comparative humidity of the atmosphere, not only as it is found in different parts of the world, but also as it varies with situation in the same country. This project would be carried into effect with the greatest ease and certainty, by diminishing the sensible powers of the hygrometer rather than by improving them. The preceding proposal is far from being new; for the same notion respecting hygrometry occurred to Dr. Franklin, so long ago as the year 1764. The idea was suggested to the Doctor by an incident, which proves the atmosphere to be drier in Pennsylvania than it is in England and France. The Doctor's thoughts on the sub- ject appeared in the first volume of the American Philo- sophical Transactions, under the form of a letter addressed to Mr. Nairne, of- London, in 1/80 : and it is superfluous to add that his sentiments are delivered with the elegance and perspicuity which distinguish the productions of this great man.
I have entertained an opinion for some time past, that a common artist might construct an instrument which would answer the purposes already specified ; and a few experi- ments were made under mv direction three or four years ago, which were far from discouraging the hope. The plan of the hygrometer here alluded to is very simple, and will be easily understood from the following description, assisted by the annexed figure.
Vol. 33. No. 131. March 1809. M In
173 Remarks on Hygrcme try.
In Plate VI. Fig. 5, AD represents a scale made of brass, writing slate, or marble ; in which the right line EF, nine or ten inches long, is divided into one hundred equal parts* This part of the instrument being prepared, take a square rod of wood, cut across the grain ; it must be four or five inches in length, and not more than a quarter of an inch in diameter : this is represented in the plate by the rectangles PL, OK and MN. One surface of this rod must be marked longitudinally by a coloured line, which is de- noted in the figure by EG and FH. After the rod has been thus marked, it must be suspended for several days in the air of a close vessel containing a quantity of quick- lime or dry potash, either of which will extract the mois- ture from the wood and bring it to a state of great dryness. When the piece is removed from the vessel, apply the end PE to the line PO, making E coincide with the top of the divided line EF, and mark the place of G, the op- posite extremity of the line EG. In the next place, sus- pend the rod for several days in the air of a close vessel containing a quantity of water, by which precaution the wood will become saturated with moisture. This being done, apply the end QF to the right line PO, making F coin- cide with the bottom of the divided line EF, and mark the place of H the other extremity of FH. Lastly, draw the right line GH, which completes the hygrometer. As oft as you wish to make an experiment with this instrument, make the end PE of the rod PL coincide with the divided line EF, taking care that the point G falls in the line GH, and observe the degree marked by E, which denotes the state of the hygrometer. The figure MN shows how this is to be done ; and it is placed in a situation which makes the point Ecoincide with 50°.
I have not the presumption to compare this apparently insignificant contrivance with the elegant hygrometer of M. De Luc. It has, however, the recommendation of sim- plicity ; and a common artist might construct a number of thein with little trouble and at little expense. They should all be cut from the same board, and made to the same scale; after which, those rods should be furnished with plates re- 2 semolina
and the Hygrometer of J, Berzelius. 1 19
sembling the original one, and preserved for use, and which were found upon trial to give correspondent results in diffe- rent parts of the scale. Dr. Franklin recommends slips of mahogany for hygrometrical purposes : my experiments, however, were made with rods of old dry deal, answering the preceding description. The preference was given to this kind of wood, because temperature has but little effect on its dimensions ; besides which, I did not recollect at the time the recommendation given to mahogany by the cele- brated philosopher of America.
Perhaps, sir, 1 should never have troubled you or any other journalist with the preceding trifle, had it not been for a paper which appears at the 39th page of your present vo- lume. This is a description of a hygrometer recommended to the public, by the inventor J. Berzelius, on the suppo- sition that Mr. Dalton's theory of mixed gases is consistent with the phenomena of meteorology. Tn attempting to vindicate the merits of his instrument, this foreigner asserts, that Dalton has proved the water of the atmosphere to be independent of the air. To this we may reply, It is a fact established by different philosophers of the last century, that water assumes the form of a gas under an exhausted receiver at any temperature greater than 32°. It has also been shown by M. De Luc, that the presence of air retards the produc- tion of the aqueous gas ; but I will venture to say that M. Berzelius goes too far when he asserts that Mr. Dalton has proved the water of the atmosphere to be independent of the air. The perfect freedom of atmospherical vapour is un- questionably a favourite opinion with this gentleman ; but in what part of his works, or in what manner, is the propo- sition demonstrated ? An explicit answer to this question" is absolutely necessary ; because M. Berzelius has adopted principles in the construction of his hygrometer, which must remain precarious until the subject in debate has been decided in favour of the new hypothesis. M. Berzelius's re- marks on Mr. Daltoo's table, ex In biting the expansive force of vapour, have nothing to do with the business of hygro- metry, so long as the preceding uncertainty can be objected to the opiuions of the latter gentleman. This table may be
M2 true
v*3P Remarks e?i HygrometnJ,
true when confined to the phsenomena of vapour produced in a vacuum ; but f am convinced that it fails in point of ac- curacy when air is present, even if the experiment he made in Mr. DaltonYown mauometer.
. Every cue who alleys the justice of the preceding argu- •ments must refuse h \o M. Berzelius, when he says
that the hygrometer should discover to what column of mercury the water gas of the air belongs ; because we are far from being certain that the air contains any water gas at all. The foregoing remarks relate to the hypothesis which suggested the hygrometer iij question. As for the instrument itself, it cannot possibly have any just claim to correctness, before the following proposition is fairly established, in con- junction with the other new doctrines already mentioned. The substances of which these hygrometers have been or shall be made, exercise no attractive force on the aqueous •gas ; on the contrary, they only diminish the temperature of this gas ; in consequence of which, part of it is condensed upon the cooling surface by the pressure of the rest. Hence it follows, that if this gas be equally cooled at the same in- stant by two different substances, it will fall in the form of water, and in equal quantities, upon them both. Various experiments, which I have made at different times, enable me to pronounce the proposition, to be incorrect; conse- quently the instrument of M. Berzelius cannot be admitted into the apparatus of a meteorologist under the name of a hygrometer. To state this objection more clearly, let me be understood to say, that if any one would try two instru- ments of the kind at the same time, one of which consisted of glass and the other of tin or silver, they would assign different expansive forces to the water gas of the atmosphere, by beginning to condense it at different degrees of tempera- ture. Besides, if we advert to some experiments by Count Rumford, it is evident that glass attracts water from the at- mosphere when we suspect nothing of the kind, and that a glass globe is frequently covered with a thin film of dew when it is supposed to be dry. Moreover, the experiments of M. De Luc inform us that the phenomena of the hygrome- ter succeed in n. vacuum, where it would be absurd to -ima- gine
and the Hygrometer of Si Berzellus. rsl
gine the vapour to be condensed by a refrigerating principle- residing in the whale-bone. — What are the genuine inferences from these facts ? 1st, That glass and other substances rob the atmosphere of water by an attractive force ; and that a loss of temperature does nothing more than prepace the air to part with its moisture more abundantly : .2dly, That the at- traction of the hvgrometer is resisted by a similar, but op*: posite power, residing in the atmosphere itself : 3d!y, That the phamomenaof the instrument are to be explained by the mutual reaction of these contrary forces.
There is one circumstance which renders the hygrometer of little or no use to the advocates of the new hypothesis r for, if I understand them tightly* a barometer will supply the place of the other instrument in their opinion. The au- thor of this-system maintains the joint pressure of the per- manent gases to be 29*56 inches of mercury at all times and places, I suppose on the level of the sea. This being ad- mitted, it will follow, that the same join! presTurl may be" found for any height; consequently, if this given quantity be subtracted from an obsened elevation of the barometer, the remainder will express the expansive force of the aqueous atmosphere for the time and place. If this be what they mean, it must convince every meteorologist that their opinion cannot explain the changes that frequently take place in the weight of the atmosphere. For instance, if the hypothesis be true, the force of the aqueous atmosphere ought to be greatest in summer, and the barometer to be highest at the same season ; — but this is not the case. On the contrary, the maximum of elevation commonly happens after the winter solstice, and the minimum too ; for the barometer frequently rises during January to 30*60 or higher; i. e. the force of the atmospherical vapour is equivalent to one inch of mercury or more. The preceding conclusion cannot be reconciled both to observation and the hypothesis; for the thermometer very seldom reaches 48°, at least in Westmoreland, during the month of January; consequently the force of the aqueous atmosphere is never equaj to -,l0th ; of an inch of mercury in this county at that season ; and the hypothesis seems to confine the range of the baromae:
M 3 to
182 Hydraulic Investigations,
to the limits 29-56 and 29*96, which is inconsistent with observation.
I will conclude this long letter by the bare relation of the following experiment, which was made in a room where a fire is kept in winter. — February 21, 1809, De Luc's hy- grometer stood at 52°, the thermometer at 50°, and the ba- rometer 29*88 inches. It is proper to remark here, that the force of the permanent gases at Middleshaw cannot exceed 29*22 inches by the hypothesis, and must be considerably less by observation ; consequently the pressure or' the va- pour was greater than '66 of an inch. A silver vessel con- taining a quart or more had been placed near the thermo- meter at the commencement of the experiment, which be- came covered with a very thin film of dew when cooled down to 40°. I am, &c,
John Gough.
XXXII. Hydraulic Investigations, subservient loan intended Croonian Lecture on the Motion of the Blood, By Thos. Young, M.D, For. Sec. R.S.
[Concluded from p. 133.]
III. Of the Propagation of an Impulse through an elastic Tube,
JL he same reasoning that is employed for determining the •velocity of an impulse, transmitted through an elastic solid or fluid body, is also applicable to the case of an incom- pressible fluid contained in an elastic pipe • the magnitude of the modulus being properly determined, according to the excess of pressure which any additional tension of the pipe is capable of producing ; its height being such, as to produce a tension, which is to any small increase of tension pro- duced by the approach of two sections of the fluid in the pipe, as their distance to its decrement : for in this case the forces concerned are precisely similar to those which are em- ployed in the transmission of an impulse through a column of air enclosed in a tube, or through an elastic solid. Jf the i>ature of the pipe be such, that its elastic force varies as the
excess
Hydraulic Investigations '. 1 83
excess of its circumference or diameter above the natural extent, which is nearly the usual constitution of elastic bo- dies, it may be shown that there is a certain finite height which will cause an infinite extension, and that the height of the modulus of elasticity, for each point, is equal to half its height above the base of this imaginary column ; which may therefore be called with propriety the modular column of the pipe: consequently the velocity of an impulse will be at every point equal to half of that which is due to the height of the point above the base ; and the velocity of an im- pulse ascending through the pipe being every where half as great as that of a body falling through the corresponding point in the modular column, the whole time of ascent will he pre- cisely twice as great as that of the descent of the failing body; and in the same manner if the pipe be inclined, the motion of the impulse may be compared with that of a body descending or ascending freely along an inclined plane.
These propositions may be thus demonstrated : let a be the diameter of the pipe in its most natural state, and let this diameter be increased to b by the pressure of the column cy the tube being so constituted that the tension may vary as the force. Then the relative force of the column c is re- presented by be, since its efficacy increases, according to the laws of hydrostatics, in the ratio of the diameter of the tube j and this force must be equal, in a state of equilibrium, to the tension arising from the change from a to b, that is, to
b — a; consequently the height c varies as —. , and if the tube be enlarged to any diameter x> the corresponding pres- sure required to distend it will be expressed by a height of
the column equal to (1 V r— , since ~7a : c : :
1 \ x/ b—a b
: ('l — — J t . Now if the diameter be enlarged
in such a degree that the length of a certain portion of its contents may be contracted in the ratio I : l — r, r bein*
very small, then the enlargement will be in the ratio 1:1+-,
TX
that is, x' will be — j but the increment of the force, or
M 4 of
184 Hydraulic Investigations*
of the height, is -- . t - , which will become - -. -.— . Now fc ' Ox I— a: 2x b — a
in a tube filled with an elastic fluid, the height being h, the
force in similar circumstances would be rk, and if we make
h= --. j _ ■> the velocity of the propagation of an impulse
will be the same in both cases, and will be equal to the ve- locity of a body which has fallen through the height \ h. Supposing x infinite, the height capable of producing the
necessary pressure becomes i— , which may be called g,
and for every other value of x this height is Q 1 — Jg3ot
g _ ' -•?, or, since h becomes ~, g — 2 h, so that h is al- ways equal to half the difference between g and the actual height of the column above the given point, or to half the Jieight of the point above the base of the column.
If two values pf x, with their corresponding heights, are given, as b and ^corresponding to c and d, and it is required
to find a; we have — ,— : c : : '— — : d, dhx — dax = cbx— dlx—cbx h dx—ch .c . . . ,
cla> and a ~ -dx^cT' or7==^-7^ThusifthebeiSht
equivalent to the tension vary in the ratio of any power m of the diameter, so that, n being a small quantity, x = b
(1 +n) and d=ci\ + mn)9 -= WWm^W^^W^
mn + n . . c . {■ b m + 1
~ — ■ — -, since the square or n is evanescent, and = m •
I 5 For example, if m = 4, - = — , and if tk = 2, 1 : a : : 3 : 2. 1 \ a 4
IV. Of the Magnitude of a diverging Pulsation at different
Points.
The demonstrations of Euler, Lagrange, and Bernoulli,
respecting the propagation of sound, have determined that
the velocity of the actual motion of the individual particles
of an., elastic fluid, when an impulse is transmitted through
a conical
Hydraulic Investigations. T83
a conical pipe, or diverges spherically from a centre, varies in the simple inverse ratio of the distance from the vertex or centre, or in the inverse subduplicate ratio of the number of particles affected, as might naturally be inferred from the general law of the preservation of the ascending force or im- petus, in all cases of the communication of motion between elastic bodies, or the particles of fluids of any kind. There is also another way of considering the subject, by which a similar conclusion may be formed respecting waves diverg- ing from, or converging to, a centre. Suppose a straight wave to be reflected backwards and forwards in succession, by two vertical surfaces, perpendicular to the direction of its motion ; it is evident that in this and every other case of such reflections, the pressure against the opposite surfaces must be equal, otherwise the centre of inertia of the whole system of bodies concerned would be displaced by their mu- tual actions, which is contrary to the general laws of the properties of the centre of inertia. Now, if Instead oi one oi the surfaces, we substitute two others, converging in a very acute angle, the wave will be elevated higher and higher as it approaches the angle : and if its height be supposed to be every where in the inverse subduplicate ratio of the di- stance of the converging surfaces, the magnitude of the pressure, reduced to the direction of the motion, will be precisely equal to that of the pressure on the single opposite surface, which will not happen if the elevation vary inversely in the simple ratio of the distance, or in that of any other power than its square root. This mode of considering the subject affords us therefore an additional reason for assert- ing, that in all transmissions of impulses through elastic bodies, or through gravitating fluids, the intensity of the impulse varies inversely in the subduplicate ratio of the ex- tent of the parts affected at the same time ; and the same reasoning may without doubt be applied to the case of an elastic tube.
There is, however, a very singular exception, in the case of waves crossing each other, to the general law of the pre- servation of ascending force, which appears to be almost Sufficient to set aside the universal application of this law to
the
136 Hydrau lie Investigations .
the motions of fluids. It is confessedly demonstrable that each of two waves, crossing each other in any direction, will preserve its motion and its elevation with respect to the surface of the fluid affected by the other wave, in the same manner as if that surface were plane : and, when the waves cross each other nearly in the same direction, both the height and the actual velocity of the particles being doubled, it is obvious that the ascending force or impetus is also doubled, since the bulk of the matter concerned is only halved, while the square of the velocity is quadrupled ; and supposing the double wave to be stopped by an obstacle, its magnitude, at the moment of the greatest elevation, will be twice as great as that of a single wave in similar circumstances, and the height, as well as the quantity of matter, will be doubled, so that either the actual or the potential height of the centre of gravity of the fluid seems to be essentially altered, when- ever such an interference of waves takes place. This diffi- culty deserves the attentive consideration of those who shall attempt to investigate either the most refined parts of hy- draulics, or the metaphysical principles of the laws of mo- tion.
V. Of the Effect of a Contraction, advancing through & Canal. If we suppose the end of a rectangular horizontal canal, partly filled with water, to advance with a given velocity, less than that with which a wave naturally moves on the surface of the water, it may be shown that a certain portion of the water will be carried forwards, with a surface nearly horizontal, and that the extent of this portion will be deter- mined, very nearly, by the difference of the spaces described, in any given time, by a wave, moving on the surface thus elevated, and by the moveable end of the canal. The form of the anterior termination of this elevated portion, or wave, may vary, according to the degrees by which the motion may be supposed to have commenced ; but whatever this form may be, it will cause an accelerative force, which is sufficient to impart successively to the portions of the fluid, along which it passes, a velocity equal to that of the move- able end, so that the elevated surface of the parts in motion
may
Hydraulic Investigations. 187
may remain nearly horizontal : and this proposition will be the more accurately true, the smaller the velocity of the moveable end may be. For, calling this velocity v, the original depth a, the increased depth x, and the velocity of the anterior part of the wave y, we have, on the supposition that the extent of the wave is already become considerable,
x = ■■S -, taking the negative or positive sign according
to the direction of the motion of the end ; since the quantity of fluid, which before occupied a length expressed by y, now
— av
occupies the length y-\-v ; and putting a sx = 2, z = -— -,
The direction of the surface of the margin of the wave is
indifferent to the calculation, and it is most convenient to
suppose its inclination equal to half a right angle, so that
the accelerating; force, acting on any thin transverse vertical
lamina, mav be equal to its weight : then the velocity y
must be such, that while the inclined margi-n of the wave
passes by each lamina, the lamina may acquire the velocity
v by a force equal to its own weight : consequently the time
of its passage must be equal to that in which a body acquires
the velocity v0 in falling through a height b, corresponding
lb to that velocity : and this time is expressed by — 3 but the
space described by the. margin of the wave is not exactly z, because the lamina in question has moved horizontally du- ring its acceleration, through a space which must be equal to /' ; the distance actually described will therefore be % ± b,
% ± b 'lb . 2by . . 2lyy
and we have -~— = , % + b at- ' av 4- Ini — bv = -
y v — v ' — J v
av9 v* __ < av* v*
+ wjt* y1 + * vy = 2h~ 2> {y + * ^ 2 = a? + & hut m
being the proper coefficient, v = m ^/ b, and v1 = mrb9 av1 ■ v* _ ,-a b \ /a b \
■tb+T6= m (2 fie)'** m i w)m ■'&* v' an-
y + v = 771 */ (— 4- — i\ + I v. But when v is small, we
.» — 1 a j ma ^ b *.. ,.
may take y + v nearly m ,/-, and z = Jj^Tj^v* <S{<>ab)%
and x m a ± J {?ab), while the height of a fluid, in which
th$
*ss Hydraulic Investigations.
the velocity would be ?/, is nearly a + f */ (c2al) : conse- quently, when the velocity v is at all considerable, y must be somewhat greater than the velocity of a wave moving on the surface of the elevated fluid ; and probably the surface ©f the elevated portion will not in this case be perfectly ho- rizontal ; but where v is imall, y may be taken, without
material error) m~ *j —, oneven m j -^-, which is the velo- city of every small wave* The coefficient m is here assumed the same for the motion of a wave, as for the discharge through an aperture, and I have reason from observation to think this estimation sufficiently correct.
Supposing now the moveable end of the canal to remain open at the lower part as far as the height c, then the excess bt" pressure, occasioned by the elevation before it, and the depression behind, will cause the fluid, immediately below the moveable plane, to flow backwards, with the velocity determined by the height, which is the difference between the levels; and the quantity thus flowing back, together with that which is contained in the moveable elevation, must be equal to the whole quantity displaced. But the depres- sion, behind the moveable body, must vary according to the circumstances of the canal, whether it be supposed to end abruptly at 'the part from which the motion begins, or to be continued backwards without limit : in the first case, the elevation z will be to the depression as v\oy — v, the length of the same portion of the fluid being varied inversely in that ratio; in the second case, the proportion will be as y -f- v to y — v : and the difference of the levels will be
y — v zy ., y—v 2zy .r
z 4- z = — i or secondly z -f z ■-■ -- = —f—i and first,
v v y-\~v y-\~v
m A/ c -J- (y — v) z — (a — c) v; but, since y is here
considered as equal to m „/ -, putting A/ — A/ h = d, y
1 2
7 1 11- "'I 7 '
— v = mdi and, calling a — c, c, m ^ -*- c '+ mdz = me V by */ 3 c -f dz = e V h cl — =i e'h + d'z1— Qdze j l,
V v
-
z* —
Hydraulic Invest' M0
Sil w rSrJ fc w and' callmg^+ ^35
* = ,/•— ^ / V) : anc* m tne samc manncr / 1S found,
for the second case, equal to 77-;-^ — 7 4- — 7— . For ex- 1 cr (y ■+■ v) d
ample, suppose the height a 2 feet, b — 1, c = 1, and con- sequently e = 1, then d becomes \y i» = 4, andy = 8; and in the first case z = . 1, and in the second % = . 14.
Iff, the velocity of the obstacle, were great in com- parison with m \r 7 , the velocity of a wave, and the space c z
below (he obstacle were small, the. anterior part of the ele- vation would advance with a velocity considerably greater than the natural velocity of the wave : but if the space below the obstacle bore a considerable proportion to the whoie height, the elevation z would be very small, since a mode-, rate pressure would cause the fluid to flow back, with a suf- ficient velocity, to exhaust the greatest part of the accumu- lation, which -would otherwise take place. Hence the ele-. vation must always be less than that which is determined by the equation m ^ zc == ev3 and z is at most equal to
(At*- \ = ~ b', but since the velocity of the anterior margin
x of the wave can never materially exceed m */ , especially
*t
x a
when % is small, and ^ •- being in this case nearly ^/— -f-
which, multiplied by z; shows the utmost quantity of the fluid that can be supposed to be carried before the obstacle.
Supposing I) — I a, this quantity becomes m A/-. ~ .-- ;
and if - be, for example, -±€} it will be expressed by To '.
an, while the whole quantity of the fluid left behind.
A similar mode of reasoning may be applied to other cases of tli e propagation of impulses, in particular to that of a;
contraction 1
190 Hydraulic Investigations.
contraction moving along an elastic pipe. In this case, an increase of the diameter does not increase the velocity of the transmission of an impulse; and when the velocity of the contraction approaches to the natural velocity of an impulse, the quantity of fluid protruded must, if possible, be still smaller than in an open canal ; that is, it must be absolutely inconsiderable, unless the contraction be very great in com- parison with the diameter of the pipe, even if its extent be such as to occasion a friction which may materially impede the retrograde motion of the fluid. The application of this theory to the motion of the blood in the arteries is very ob- vious, and I shall enlarge more on the subject when 1 have the honour of laying before the Society the Croonian Lecture for the present year.
The resistance, opposed to the motion of a floating body, might in some cases be calculated in a similar manner : but the principal part of this resistance appears to be usually de- rived from a cause which is here neglected ; that is, the force required to produce the ascending, descending, or lateral motions of the particles, which are turned aside to make way for the moving body; while in this calculation their direct and retrograde motions only are considered.
The same mode of considering the motion of a vertical lamina may also be employed for determining the velocity of a wave of finite magnitude. Let the depth of the fluid be a, and suppose the section of the wave to be an isosceles triangle, of which the height is b, and half the breadth c: then the force urging any thin vertical lamina in a horizon- tal direction will be to its weight as b to c; and the space d, through which it moves horizontally, while half the wave passe* it, will be such that (c—d). (a + \b) = ac, when,
be
ced = r. But the final velocity in this space is the
'la -f b J r
same as is due to a height equal to the space, reduced in
the ratio of the force to the weight, that is, to the height
-7, and half this velocitv is £ m J ( — • — 7 ), which is
la + b ' \2a -j- 0/
the mean velocity of the lamina. In the mean time the wave
describes
On the Icy Crust formed oh Glass Windows, &c. 19I describes this space c + d, and its velocity is greater than
that of the lamina in the ratio of -?+ 1 to 1. that is — ; —
a v
la « . . /a , \ h
+ 1 or -b + 2 to 1, becom.ng»(i-+ »)v(aa + t)=»«
0, 4* * • 1 a
; which, when h vanishes, becomes m V" r > as
in Lagrange's theorem, and, when h is small, m ( *J - -f --
— tt — ttt^ , or m - — 7-— : but if a were small, it would
approach to m ^ l9 the velocity due to the whole height of the wave.
XXXIII. On the Icy Crust formed on Glass .Windows du- ring a severe Frost : — with a few Remarks on Marine Ve~ getables. By Mr. James Graham, of Berwick-upon- Tweed,
To Mr. Tilloch, — Sir, If you think the following observations on the crust formed on windows during a severe frost merit a place in your very useful and entertaining Miscellany, they are much at your service.
This curious phaenomenon is so common, that I believe there are very few who have not taken some notice of it ; but, like many of the other appearances in nature, which strike the mind of the philosopher or the contemplative ob- server with wonder and astonishment, with the great bulk of mankind it excites not the least surprise. Such seem* to be the general weakness of the human intellect, that we all require some friendly hand or kind assistant to first " rear the tender thought, or teach the young idea how to shoot. " The appearance to which I wish to call the at- tention of your readers is the various figures which are re- presented on the glass where this crust is formed. T have found some, whose curiosity was in a certain degree excited, suppose that all was merely accidental, .or formed by what we often call chance: but, on a closer observation, this v. ill
tig& Qn the Icy 'Crust formed on Glass Windows
not be found to be the case ;-^rwhen strictly .examined, every* figure is as regularly formed as if drawn by the hand or a skilful artist, and the \vnole exhibits, as it were, a beautiful ation of various marine or sea plants. Sometimes there IS an exact representation of the plant from which that spe- cies of ashes or alkali commonly cajled kelp is made; — on other parts of the glass will be seen a perfect likeness of some ot the smaller .Vegetable productions, which, from a sniall root, branche out into an astonishing number of very tine fibres, joined together in such curious workmanship as far to excel 1 any land production (at least that. I have observed) ; indeed no description which I can give, without a drawing, can convey any idea either of the beauty or cu- riosity or* these several icy arboriiications. A few of the larger kinds I have sometimes observed during a continued frost; but the more common appearances resemble the plant from which the kelp is made, and the smaller vegetable pro- ductions. I wish to be informed by any of your learned and philosophical readers, What can be the natural cause which produces this effect ? Surely we cannot ascribe it to mere accident; for if this were the case, there certainly would not be the same regular uniformity. It may, however, be ne- cessary to observe, that this uniform appearance will some- times be broken; but on strict examination I have always found it to proceed from some such circumstance as a sudden change in the temperature of the air in the room by an in- crease of company, or a larger tire, ike: these will some- times in a certain degree melt the crust on the glass, and if again suddenly frozen the regularity of the figures will ap- pear broken ; but where Nature is left to operate without interruption, I have always found the result the same.
I can scarcely omit this opportunity of directing your at- tention to another observation, which I doubt not will be grateful to some of your readers, as enlarging the sphere of their curiosity, and giving a more ample scope to the con- templative mind : —
The first sight of the sea to a person who has lived to the years of maturity without seeing it, (and even in this island there are many,) I am apt to think is the greatest object
which
during a severe Frost, 1 93
Which Nature presents to the mind on this terraqueous globe. If the survey is made on a calm summer's day, the clear, smooth, and extended surface, which is bounded only by the horizon, stretching as far as the eys can reach, fills the mind with the most pleasing wonder and surprise;1 while the imagination is left to roam at large on the supposed ex- panse which lies far beyond the circle which the eye can embrace. If the survey is made in the winter, especially during a storm, what a grand and awful spectacle is pre- sented, particularly to any person not accustomed to the scene ! The deep *and hollow sound of contending waves catches the ear at a great distance : but when the eye comes to survey a seemingly boundless ocean rolling in constant succession its tremendous billows, till they dash with such impetuous force on the shore as to threaten destruction to the very rocks and banks which Nature has placed as a barrier to its almost irresistible fury, the mind is filled with amaze- ment.
These are appearances so peculiarly grand, that they arrest the attention of even the careless and indifferent spectator. The objects to which I beg leave to direct the inquisitive mind, which finds pleasure in observing and examining the great variety of Nature's productions, is the vast quantity of ma- rine plants which are to be found on the shore and amongst the rocks during the ebb tide: — these are often thrown up in such promiscuous heaps on the beach, that superficial observers do not think they can deserve any attention : nor will they easily be induced to believe that the mind of the traveller is not more astonished when he first visits the torrid zone, and finds every tree, every shrub and plant, in short the whole vegetable creation, different from any thing he had seen in the more temperate climates, than any person will be when he first examines the productions of the ocean. I shall not attempt to give any delineation of this vegetable kingdom : even if my abilities were equal to the task, it would far exceed the limits of a short essay: but I will ,v^m\ assure all who have not made the experiment, that their pains and trouble will be amply repaid, and their curiosity fully grati-
Vol. 33. No. 131. March 15Q9. N fied.
194 On the basaltic Surface of the Counties
fled. I cannot, however, conclude without one more ob- servation: — During the ebb tide, }f the shore is rocky, a number of small pools of clear water are left, in which will be found many of the smaller plants adhering to the stones or rock, which, if carefully removed, and, before they are too dry, spread on white paper, will exhibit a most beauti- ful and pleasing variety without the trouble of drawing. I am, sir, your most humble servant,
James Graham.
Berwicloup on-Tee d, , -~
Feb 1, 1809.
XXXIV. A Letter on the Alterations that have taken place in the Structure of Rocks, on the Surface of the basaltic Country in the Counties of Deny and Antrim. Addressed to Humphry Davy, Esq., See. R. S. By William Richardson, D. D.
[Concluded from p. 116.]
Inquiry into the Formation of our perpendicular Facades.
At is natural that the first great operation we proceed to in- vestigate, should be the formation of our magnificent fa- cades, one of which is the principal subject of this memoir.
The line of coast that bounds our basaltic area on its north side, extends about twenty-five Irish miles, in which course the precipices are nearly continuous, and more than one half of them absolutely perpendicular for a great part of their stupendous height. The operation by which they were cut off so abruptly, and left with a formidable aspect towering over our coast, is the one we inquire into.
That these bold precipices once projected further in many places is easily demonstrated ; at Bea/iyn Daana, and at the Chimney, the columnar construction was obviously once carried much further out.
At the Milestone, Portcooan, and Portnalau. the fragment? of dykes extend far beyond the face of the precipice.
These same facts, together with the projecting base, show tfrat these sudden abruptions were not formed by the sub- siding.
of Deny and Antrim. 1 95
siding, and sinking of one part, leaving the remainder in its place ; still less by any violent revolution, or convulsion, as the stratification has not sustained the slightest shock either above or below the facade.
The formation of our abrupt coast, has been ascribed to the action of the sea beating violently against it, washing away the lower parts, and leaving a perpendicular facade standing; as we often see on the banks of rapid and en- croaching rivers.
A cool examination of our precipices will soon prove that our facades could not have been so formed ; for we always find them on the highest part of the cliff, and receding from the water, which could be instrumental in bringing down the materials from above, only by washing, and so wearing away the bases of the steepest parts ; but the elevations of these bases are utterly irreconcileable to this supposition ; for instance, the base of Pleskin facade is two hundred feet above the present level of the sea, that of Fair head three hundred: now had the sea ever risen to either height, it would have submerged a great part of Ireland, and none of the neighbouring country (whatever its level may be) bears the least resemblance to alluvial ground, nor shows any mark of having been once covered by the sea.
The next argument is still more conclusive : the boundary of our basaltic area on its north side, is for twenty-five miles also the confine of sea and land ; so far it is natural to ascribe its features, and characteristic marks, to the action of the powerful element that beats against it. But when that pre- cipitous boundary ceases to be the confine of sea and land, turns southward towards the interior, and becomes the line of demarcation between the basaltic and sdiistose country on the west, it still preserves its former character : that is, of a range or ridge of very high land, steep to the exterior, and sometimes cut down vertically into facades, like its northern part that lines the shore.
Thus Magilligan Rock (four miles inland) is not inferior in magnificence to any of our facades on the coast : its per- pendicular section is one hundred and seventy feet, and this continuous for a mile ; the facades at Bienbraddock are nine
N 2 miles
196 On the basaltic Surface of the Counties
miles further inland, and those of* Monyneeny thirteen ; while the hase of the lowest of these perpendicular precipices is elevated 1400 feet above the sea.
The same style prevails on the east side of our basaltic area, after its boundary ceases to be the confine of sea and Jand ; for the limestone facades at Garron Point (consi- derably above the level of the sea) exactly resemble those of Dunluce and Kenbaan at the water edge; and Cave Hill (several miles from the sea, and nearly one from the shallow estuary of Belfast,) exhibits basaltic facades at the height of one thousand feet, precisely similar, and little inferior to those of Magilligan,
The exact resemblance between our inland facades (on the east and west sides of our area) to those on the shore, proves them to be all effects from the same cause, and that our accumulated strata have in all these similar instances been cut down vertically by the same agent, and that this agent was not the sea.
Nor has this powerful agent confined its operations to our coast, or to the periphery of our basaltic area j we can trace it over its whole surface; we find throughout its interior, similar, though very diminutive abruptions, executed pre- cisely in the same manner, that is, strata cut across by a long vertical fagade, their planes on the upper side perfectly undisturbed, while on the lower side all the materials of which that part of the stratum was once composed are com- pletely carried off. — (See 6th fact.)
We are now unavoidably led into a discussion of a queS- - tion which has at all times occupied the attention of natu- ralists.
, Whence arise the Inequalities with which the Surface of the Earth is so exceedingly diversified P
I shall not attempt to encounter this question generally, nor to extend my inquiries beyond the limits I have pre- scribed to myself; but I shall try whether the curious facts so profusely exhibited over our basaltic area, throw any light upon the formation of our own inequalities, or lead us a step 8 towards
of Deny and Antrim. 1 97
towards the discovery of the operations by which such stu* pendous effects have been produced.
Some, to escape the difficulties in which this question is involved, ascribe our inequalities to original formation; as if the world had come from the hand of the Creator with the variegated surface which now contributes so much to its beauty ; but the frequent interruptions, and resumptions of the strata in our area, with the perfect resemblance of the corresponding parts, however great the interval by which they are separated, can scarcely leave a doubt that these strata were at first continuous ; of course, the figure of our surface at that time must have depended on the original po- sitions and inclinations of these strata, which, as appears by the 3d fact, are now unconnected with the superficial line, the figure of which is governed by their abruptions and removr.ls alone.
Naturalists have differed much in opinion as to the direc- tion in which the causes acted that produced the inequalities on the surface of our globe ; some referring us to the bowels of the earth as to the scene of action ; while others assert that the operations were performed upon the surface itself.
But the slightest inspection of our facades will at once prove that the first hypothesis cannot be correct ; for obli- quity of direction must have been the result of a- disturbing cause acting from below ; whereas parallelism and a steady rectilineal course distinguish the basaltic arrangements of which I have been treating.
We have, it is true, occasional depressions of our strata, where they obviously have subsided, and no doubt from a failure of support below ; but in no instance that I have met with, in our area, are these attended by the slightest con- cussion ; the permanent and subsided parts, with us still preserve their parallelism, and the continuity of their mate- rial 5 whence it is probable this event took place previous to the induration of the strata, and of course antecedent to the period to which I limit myself.
Buffon ascribes our superficial inequalities to the agitation of the waters while they covered our earth, and argues from the resemblance these inequalities bear to the waves of the
N3 sea;
J 98 On the basaltic Surface of the Counties
sea ; a resemblance I cannot trace in any country which I have observed, nor could our sudden and perpendicular ab- ruptions ever have been produced by any agitation of the waters.
Professor Playfair considers rivers as having formed not only the. beds or channels in which they flow, but also the whole of the valleys through which they run, and in gene- ral all the inequalities of our surface; but an attentive ob- server, tracing the course of any of our most rapid rivers, would soon perceive that the quantity of its depredations have been comparatively insignificant, and that they can be determined with precision : the river has no doubt in several places extended itself considerably on both sides, but in the intermediate space between the remotest boundaries it ever reached, it levels, instead of raising inequalities.
The same result I apprehend would follow from the ope- rations of another agent, which theorists are in the habit of calling in to their aid, when they cannot find some certain material, which from their theory we had reason to expect ; they then tell us it has been carried off, and lost in the suite of degradations and decompositions.
But decay and decomposition, instead of creating inequa- lities, would produce a contrary effect, and deface those ac- tually existing; they would gradually abate the height of our perpendicular facades, and increase the green steep at their bases by the accumulation of the crumbling and mouldering materials from above ; while the more diminutive facades formed by the abruptions of single strata scattered over the face of our area, and forming its most characteristic feature, would in time (as many are already) be converted into steep acclivities covered with verdure.
Such are the principal causes to which the inequalities of our surface have been generally ascribed. Previous to our deciding finally upon their insufficiency, it may be proper to enumerate a few of those inequalities, where the deviation of our present surface, from the form it probably had origi- nally, is not only striking, but where also the concomitant circumstances afford demonstration, that some great opera- lion has once taken place there,
Thus4
of Deny and Antrim. ^ 199
Thus, by making ourselves acquainted with effects, we shall be better qualified to investigate causes : and if those effects shall appear to be beyond the powers of such natural agents as we are already acquainted with, we shall be justi- fied in admitting the performance of operations to which we have seen nothing similar ; and also in admitting the former existence of powers of far superior energy to any we have ever known in action.
Enumeration of some remarkable Inequalities in the Surface
of our lasaltic Area, produced since the Consolidation of
its Strata,
That we may better understand the facts I am proceeding to state, I shall assume (in the style of the mathematicians puta factum) previous to demonstration, that the planes of our uniform, rectilineal strata, however interrupted we may now find them, were once continuous.
Upon this supposition, the valley of the Mayola, between the stratified summits of Seqfin and Slievegallon, u an ex- cavation 1 700 feet deep, and three miles wide, of which the whole materials have been completely carried off.
To the northward of this excavation, between Seafn and Carntogher, the continuous accumulated strata of basalt are interrupted, and taken away quite down to the schistose sub- stratum ; while the untouched summits of the contiguous mountains, Carntogher, Seafn, and Monyneeny, are still stratified basalt.
On the eastern side of our area, immediately to the southward of Kello and Connor, a similar operation has been performed, attended by still more extraordinary circum* stances.
We here find a district near four miles in diameter, caltal the Sandy Braes ; over this whole space the basaltic strati- fication has been carried off, and the operation has reached deep into a very singular substratum, a reddish breccia, by some mineralogists called a porphyry, the mass friable, but the component angular particles of extreme hardness.
The hills, of which this little district is full, are every one perfect segments of spheres, while the loftier basaltic
N 4 hill*
200 On the basaltic Surface of the Counties
hills that surround it preserve their characteristic form, to witj a gradual acclivity on one side, with a steep abruption on the other.
As we sail along our northern shore we discover another great chasm or interruption of our strata, which also cuts deep into the substrata : for on the west side of Bqllycastle pier, the bold basaltic precipices suddenly disappear, and at a lower level disclose the substratum, which appears to be an alternation of sandstone, and coal, sometimes with bitu- minous schistus.
A mile or two to the eastward the abrupt precipice is re- sumed, and a basaltic stratum again occupies its summit on to Fairhead, with the same angle of inclination in which it was disposed along our whole coast, that is_, a slight ascent \o the north.
Traces of similar operations and abruptions are to be found over our whole area, but the preceding are sufficient to make us acquainted with the style of these interruptions of our strata ; of course it is time to proceed to the suspended de- monstration, that our strata, so interrupted, were once con- tinuous, notwithstanding the magnitude, of the interval by which the corresponding parts are now separated.
Proofs that our now interrupted Strqta were once continuous,.
We must now turn ba,ck to the facades o^Bengore, where the strata themselves, and all the circumstances attending them, are so happily displayed, as to throw great light on the subject, and to lead us analogically., step by step, to the conclusion we seek for,
X^et us examine and trace the summit of the precipice for a mile immediately eastward from the Giant's Causeway, and we shall find a frequent interruption and resumption of the fourth, fifth, and sixth strata, at the shortest intervals,, the interruption not always reaching to. the lowest of the three, which in that case remains continuous : so far simple inspection removes all doubt, that each of these strata was Once continuous as far as the great depression to the west of Pie. skin.
£Jere indeed the interruption becomes considerable, not
less,
of Berry and Antrim. 201
less than a mile ; but when we find at Port-moon a succession of three strata with the same inclination, in the same order, of the same thickness each, and with the same strong cha- racteristic marks that distinguished the three interrupted, at the depression ; above all, when we find the strata they rest upon continuous (at least with very trifling interruptions) for the same extent ; I think we. can scarcely entertain a doubt that this interval between the corresponding parts, though so m;ich greater than any of the preceding, is, like then), but an interruption, and that these strata -were once continuous from the depression to Portmoon,
The same style of induction would establish the quondam continuity of all the strata in the face of Bengore promon- tory, for here the strata are so distinctly marked that we know each of them when we find it again after any inter- ruption.
In the rest of our precipices and facades, the similarity of the strata deprives us of this advantage; yet in their smaller interruptions, the eye, by tracing the rectilineal course of the strata, and so connecting the separated parts, can esta- blish their former continuity : while in the greater intervals we must rest our proof on analogy alone.
That we may be entitled to carry this style of induction into the interior of our basaltic area, and to apply the same reasoning to enable us to form a similar decision upon the more stupendous interruptions of our strata, which I have already enumerated, it becomes necessary to explain the geo- logical construction of our area, — the strata of which it is formed — their arrangement — and their inclinations.
An extensive limestone stratum, white as chalk, and about two hundred feet thick, seems to form the base of the whole district I limit myself to : upon this, accumulations of rec- tilineal and parallel basaltic strata, are heaped up to most unequal heights.
This great calcareous stratum seems not to be an accurate plane, but rather to resemble a bason, as every where at its periphery it dips to the interior ; yet the plane of its section has a slight ascent to the southward : a recollection of these circumstances will enable us to account for every appearance
this
202 On the basaltic Surface of the Counties
this stratum exhibits, as it happens to be disclosed to us ; and by the converse, an attention to these appearances will Gnable us accurately to determine the position of the stratum.
This stratum, from Bally castle to Solomon's Porch, (about twenty- five miles,) keeps very nearly the level of the sea, often indeed sinking below the surface, but never raising its lower edge above it : but when at Solomon's Porch, the bouudary of our basaltic area begins to deflect to the south- west, and then to the south, the ascent of the stratum to the southward begins to operate, and we perceive the dotted line of its quarries gradually to rise along the face of the mountain from the shore to Monynceny and Seqfin, where is has attained the height of 1500 feet: it is true, the actual stratum has not been opened at these two great elevations, but the white rubble immediately below the basaltic facade proves incontestably that it is close at hand.
An accumulation of basaltic strata, had in this southern course, as well as on the northern shore, covered the lime- stone up to the summits of the hills or mountains.
I have already stated how the ridge of mountain is sud- denly interrupted by the valley of the Mayola, from 1600 to 1 700 feet deep ; but if we look to the southward, in the rectilineal course of the strata (the positions of which we have been able to ascertain with so much accuracy), wc shall find near the summit of the mountain Slieve gallon a similar white limestone stratum crowned with basalt, cutting it in the very direction the former ought to have reached it, that is perhaps two hundred feet higher, the ascent of the strata to the southward having elevated their planes so much in a distance of four miles, the probable interval between the summits of these mountains.
We arc now to decide whether this calcareous and basaltic fragment, on the summit of Stievegatton mountain, be the last remnant of the old arrangement we have been tracing, and ascertaining with so much precision, for seventeen or eighteen miles from the sea, aud twenty- five miles along the coast, but now interrupted by the valley of the Mayola, like our former more diminutive interruptions, and also like them resumed at the next elevation, in the same rectilineal
course,
of Deny and Antrim. 203
course, the strata preserving the same order, and the same characteristic marks. Or whether these strata, appearing on the summit of Slievegallon, be the commencement of a new arrangement, abandoned by nature as soon as begun : which is highly improbable, for neither limestone nor basalt' are to be found on the mountain except in this solitary hummock.
We might, by a minute attention to the inclinations and arrangements of the strata contiguous to the other inter- ruptions I have enumerated, prove in like manner that the basaltic masses crowning the summits of the surrounding hills and mountains, are merely the remnants of strata once extensive and continuous, but interrupted and carried off, as in the preceding case, by the same powerful agent.
The more diminutive inequalities scattered over the whole surface of our area, and always produced by interruptions of the strata, would still more easily admit the application of the same reasoning, from the contiguity of their abrupt ed parts ; but the detail would be tedious ; those who wish to pursue the subject further must come to the scene them- selves.
Materials completely carried off. A circumstance perhaps still more extraordinary, is the complete removal of all the materials that once filled up the intervals between the abrupted parts of these strata. I have stated in my 9th fact, that the materials that had formerly composed the projecting parts of our northern facades and precipices, had totally disappeared.
The removed parts of the limestone stratum on the west side of our area have shared the same fate, for where the chain of mountains extending from Mugilligun Rock to Bienbraddocky is interrupted by valleys at Slradreagh, Drum- rommer, and Ballyness, it is obvious that the limestone stra- tum was once continuous to the high points where it shows, itself on Ready, and the mountains on each side; its thick- ness too, wherever we can try it, is very great ; vet this stratum, which in its entire state must have spread like a roof far above the present surface of these valleys (which are
now
304 On the basaltic Surface of the Counties
now sunk deep into the schistose substratum) has not left a particle of its debris behind, nor is a single lump of white limestone to be found, until we come to the quarries, that is, to the edge of the solid, untouched stratum.
Conclusions.
The conclusions that unavoidably follow, from the con- sideration of these facts, are,
That the hills and mountains, in the district I have been describing, were not raised up or formed as they now stand, but that they are the undisturbed remains of strata that were left behind, when stupendous operations carried away the parts that were once contiguous to them.
That the inequalities of this surface were all produced by causes acting from above, and carrying off whatever they touched, without in the least disturbing what was left be- hind.
Additional Evidences. Basaltic Hummocks* .
The arguments on which I have founded my opinions have hitherto been all taken from the hollows in our surface, and the interruptions in our strata, both which, the con- comitant circumstances have led me to cons-ider as so many excavations ; but the lofty elevation's, and the abrupt pro- minencies rising suddenly from our surface, when minutely examined, lead us irresistibly to the very same conclusion.
When you and I examined together the line of our north- ern facades, we studiously sought for the points where na- ture had made any change in her materials or their arrange- ment, hoping that at the junctions of these little systems, we should find some facts that would throw light on the subject; but we generally failed ; want of perpendicularity, or other local circumstances, impeding us at the most in- teresting points.
On the present occasion she has adopted an opposite line of conduct, and in many of the steps she has taken, ob- trudes upon us demonstration of what she has done.
* Navigators use the word hummock to express circular and elevatj-d mounts, appearing at a distance; I adopt the term from them.
Whoever
of Derry and Antrim. £0$
Whoever has attended to the exertions of man when em- ployed in altering our present surface, either by levelling heights, or by making excavations, must nave observed that it is the practice of the workmen to leave small cylindrical portions standing, for the purpose of determining the height of the old surface, and thereby ascertaining the quantity of materials removed.
To these may be compared the stratified basaltic hum-' mocks so profusely scattered over our area, and which seem- to show how high our quondam surface once reached.
The hummock df Dunmull, three miles south-east from Fortmsh, is very beautiful, it stands on the top of a high ridge, and is a conspicuous object from all parts of the country ; it is exactly circular, its flat surface contains art acre, it is completely surrounded by a perpendicular fagade about twenty-five feet high, and formed by two strata, a columnar, and an irregular prismatic, resting upon it.
From this elevated station, where I had the pleasure of accompanying you, I showed you at six or seven miles di- stance to the westward, among the Derry mountains, the still loftier hummocks of Altabrian and Sconce, hemisphe- rical in form, composed of but one stratum each, while their swelling out bases displayed accumulations of many more: and also near those the hummock of Fermayle, resembling Dunmull^ but much larger, and also surrounded by a fa- cade composed of tw-o strata.
I showed you also at twenty miles distance to the south- east, the gigantic Sltmish, one of our basaltic hummocks, magnified (as it were) into a lofty and insulated mountain, completely stratified from its base to its flat summit.
I showed you likewise from the bottom of its ridge, the neat but diminutive hummock, called the Rock of Clog her, above Bushmills, As our time was precious, you took my word for its stratification being precisely similar to that of Dunmull.
There are many other basaltic hummocks scattered over the surface of our area, all of them either stratified or por- tions of strata; two of the most remarkable are the hill of
Knock
206 On the basaltic1 Surface of the Counties
Knock Lnughran, near Maghera, and a tall hummock (whose name I forget) a mile eastward from LisanoUre*
We meet still more frequently an imperfect style of hum- mock, a semicircular facade one side, while on the other it slopes away gradually with the dip of the strata, as if the operation had been interrupted before it was carried quite round ; the most remarkable of these are Bally strone, in Deny, and Croaghmore, in Antrim, both visible from Dunmull.
Regular stratifications on the summits of hills and moun- tains have been long a stumbling-block to theorists ; the historian of the French Academy, for the year 1716, ob- viously ascribing the superficial inequalities of the earth, (like many others) to causes acting from below, and per- ceiving how incompatible such assemblages of strata were to his theory, thinks it safer to doubt their existence, as they could not have been formed, he says, " unless the masses of the mountains were elevated in the direction of an axis per- pendicular to the horizon : ce que n" a pu etre que ires rare"
But as these stratified mounts are in our area by no means uncommon, they lay us under the necessity of suggesting another alternative similar to those we have already stated.
Were these isolated hummocks originally formed as they now stand, (solitary and separate from each other) one by one; or, are they the last remaining portions of a vast con- solidated mass, of which the intermediate and connecting strata have been carried off by causes with which we are un- acquainted ?
To be able satisfactorily to resolve this alternative, it be- comes necessary to take a careful view of the contiguous countries, and to try whether their construction, and the arrangement of their strata, will throw any light upon the subject.
When we examine the assemblage of hummocks above Knockmult, that is, Sconce, Fermoyle, and Altabrian, we find their materials and stratification precisely similar to that of the country below them to the eastward, where the abrup- tions of the strata are displayed in long stony ridges—- to the
south,,
of Berry and Antrim. 20?
south, the abruptions on the summit of Keady mountain discover the same similarity; and to the north-west the grand facade of MagUligan Rock, three miles distant, dis- plays an accumulation of exactly the same sort of strata con- solidated into an enormous mass,
The hummock of Dunmull is formed of two very parti- cular strata, a columnar, and an irregular prismatic ; but I showed you, a mile to the northward, at the facades and quarries of Islamore and CraigahuUer, at the base of the hill, that the whole ridge, on the summit of which Dunmull is placed, was a consolidated mass, formed by alternate strata of the same description : and that the arrangement of the whole country below, and adjacent, was precisely the same with that of the hummock of Clog her, I proved to you at the curious opening of the strata at Bushmills Bridge, and in the facades at the Giant's Causeway,
After these proofs that so many (and I might proceed to the rest) of our detached hummocks are in their construc- tion and materials, similar to, and connected with, the main consolidated masses of which our country is formed, I think it will scarcely be asserted that these hummocks were origi- nally formed, solitary and separate as they now stand j but rather that they were once parts of that vast whole, and left behind in their present form, upon the removal of the con- tiguous portions of their strata, by some powerful agent, of whose operations and modes of actings we have hitherto ob- tained little knowledge.
The highest point on the facade of Cave Hill is called Me/lrt's Castle, and appears to be a solitary fragment of a stratum, precisely similar to those below it, and obviously once extended like them.
The irregularity of the summit of Fairhcad, plainly shows that its gigantic columns once reached higher.
And in the facade of MagUligan, the highest of all, a few desultory patches of an upper stratum (no doubt once perfect and continuous) are to be traced along its summit.
Our mountains themselves seem to show clearlv that they were once higher ; the top of MagUligan mountain is an ex- tensive
£08 Method of Preserving Fruit without Sugar, tensive plain, over which a wandering stratum is interrupt- ed and resumed at intervals for a great way.
At the highest part of Donald's Hill, over the valley of Glennuller, we find a hummock ; also at the termination of the ridge, at its highest part over the vallev of Mayola, si- milar hummocks. I have the honour to be, sir,
your obedient humble servant, .
Clonfecle, Jan. 2, 1808. W. RlCHARDSON,
XXXV. Method of Preserving Fruit without Sugar, for House Use or Sea Sto?-es. By Mr. Thomas SAddington, of Lower Thames Street, London*.
SIR,
J. shall be much obliged to you to lay before the Society of Arts, &c, the inclosed communication, and a box con- taining the following fruits in bottles, preserved without sugar; namely, apricots, gooseberries, currants, raspberries, cherries, Orleans plums, egg plums, green gages, damsons, and Siberian crabs. I have also sent some fresh English rhubarb plant, preserved in a similar manner, The same mode is applicable to other English fruits, as cranberries, barberries, and many more. This manner of preserving fruit will be found particularly useful on ship-board for sea stores, as the fruit is not likely to be injured by the motion of the ship, when the bottles are laid down on their sides, and the corks kept moist by the liquor, but on the contrary will keep well even in hot climates.
The cheapness of the process will render it deserving of the attention of all families from the highest to the lowest ranks of society* ]f the instructions I have sent are well attended to, I have no doubt that whoever tries my method will find it to answer his expectation.
I am, sir, your most obedient humble servant,
Thomas SaddingtOn.
London, Jan. 8, 1808.
To C. Taylor, JVLD. Sec.
* From Transactiovs of the Society for the Encouragement of Arts, Manu- factures, and Commerce, for 1807.-* rive guineas were voted by the Society
to Mr. Saddington for this communication.
A new
for House Use or Sea Stores, 209
A new MetJiod to preserve various Sorts of English Garden and Orchard Fruit, without Sugar,
GENTLEMEN,
The general utility, as well as luxurious benefit, arising from the fruil produced by our gardens and orchards, is well known and acknowledged at the festive board of every fa- mily j nor is this utility and benefit less manifested by a de- sire of many persons to preserve them for culinary purposes, in the more un bountiful season of the year ; and I am well persuaded that this commendable desire would be greatly extended in most families, was it not attended with so much expense as is generally the case by preserving fruit in the colli mon mode with sugar, that article chiefly constituting the basis by which it is effected. In addition to the expense of sugar, which is frequently urged as a reason for not pre- serving, there are other objections to that method, and what T am about to mention cannot be considered as the least, namely, the great uncertainty of success, occasioned by the strong fermentable qualities contained in many sorts of fruit. It may be said by some, that fruit may be preserved for a length of time without sugar by the ordinary mode of baking or boiling, and being closely stopped up, to which assertion I freely assent 3 but even that method is frequently attended with uncertainty ; for if the cork or other means used for keeping the external air out of the vessel becomes dry, or from any other cause the atmospheric air exchanges place with what is impregnated by the fruit, it soon becomes mouldy and unfit for use.
From these considerations, and a desire of preserving fruit at a trifling expense, I have made various and successful experiments of doing it without sugar, and at the same time with a certainty of their retaining all those agreeable flavours which they naturally possess ; and it is highly probable that they will keep perfectly good for two or three years, or even a longer period, in any hot climate, by which it appears to become a valuable store for shipping or exportation, as I have exposed them to the action of the meridian sun in an upper room, during the whole of the summer, after they
Vol. 33. No. 131. March 1SO0. O have
iilO Method of preserving Fruit without Sugar,
have been so preserved (being clone in 1S06). I have now the pleasure of laying before the Society specimens of the fruit alluded to.
Process for preserving Fruit, The bottles I chiefly use for small fruit, such as goose- berries, currants, cherries, and raspberries, are selected from the widest-necked of those used for wine or porter, as they are procured at a much cheaper rate than what are generally cialled gooseberry bottles. Having got them properly cleaned, and the fruit ready picked, (which should not be too ripe.) fill such of them as you intend doing at one time, as full as they will hold, so as to admit the cork going in, frequently snaking the fruit down whilst filling. When done, fit the corks to each bottle, and stick them lightly in, so as to be easily taken out when the fruit is sufficiently scalded, which may be done either in a copper, or large kettle, or saucepan over the fire, first putting a coarse cloth of any sort at the bottom to prevent the heat of the fire from cracking the bottles : then fill the copper, or kettle, with cold water suf- ficiently high for the bottles to be nearly up to the top in it : put them in side-ways to expel the air contained in the ca- vity under the bottom of the bottle ; then light the fire if the copper is used, taking care that the bottles do not touch the bottom or sides, which will endanger their bursting ; and increase the heat gradually until it comes to about one hun- dred and sixty or one hundred and seventy degrees, by a brewing thermometer*, which generally requires about three quarters of an hour. For want of such an instrument it may be very well managed by judging of the degree of heat by the finger, which may be known by the water feeling very hot, but not so as to scald it. If the water should be too hot, a little cold may be added to keep it of a proper tem- perature, or the fire may be slackened. When it arrives at a sufficient degree of heat, it must be kept at the same for about half an hour longer, which will at all times be quite enough, as a longer time, or greater heat, will crack thc fruit. During the lime the bottles are increasing in heat,
'* Fahrenheit'*.
a tea-
for House Use or Sea Stores, 21 i '
a tea-kettle full of water must be got ready to boil as soon as the fruit is sufficiently done. If one fire only is used, the kettle containing the bottles mtlst be removed half off the fire, when it is at the full heat required, to make room for boiling the water in the tea-kettle. As soon as the fruit is properly scalded, and the water boiling, take the bottles out of the water one at a time, and fill them within an inch of the cork with the boiling water out of the tea-kettle. Cork them down immediately, doing it gently, but very tight, by squeezing the cork in ; but you must not shake them by driving the cork, as that will endanger the bursting of the bottles with the hot water : when they are corked, lay them down on their side, as by that means the cork keeps swelled, and prevents the air escaping out : let them lie un- til cold, when they may be removed to any convenient place of keeping, always observing to let them lie on their side until wanted for use. During the first month, or two, after they are bottled, it will be necessary to turn the bottles a little round, once or twice in a week, to prevent the fer- mentation that will arise on some fruits from forming into a crust, by which proper attention the fruit will be kept moist with the water, and no mould will ever take place. It will also be proper to turn the bottles a little round once or twice in a month afterwards.
Having laid down the method of preserving fruit without sugar, in as clear and concise a manner as possible, I will recapitulate the whole in a few words, which may be easily remembered by any person. Fill the bottles quite full with/ fruit. Put the corks in loosely. Set them in a copper, or kettle of water. Increase the heat to scalding for about three quarters of an hour; when of a proper degree, keep at the same half an hour longer. .Fill up with boiling water. Cork down tight. Lav them on their side until wanted for use.
It mav be said as an additional reason as well as cheapness, for using wine or porter bottles, instead of gooseberry, is the difficulty of obtaining them, even at any price, in some parts of the country; and indeed they are equally useful for small fruit, and answer the purpose quite as well, excepting the little inconvenience of getting the fruit out when wanted
~0 2 for
212 Method of preserving Fruit without Sugar,
for use, which may be easily done by first pouring all the liquor out into a bason, or any other vessel, and then with a bit of bent wire, or small iron meat skewer, the fruit may be raked out. Some of the liquor first poured off", serves to put into the pies, tarts, or puddings, instead of water, as it is strongly impregnated with the virtues of the fruit, and the remainder may be boiled up with a little sugar, which makes a very rich and agreeable syrup.
Jn confirmation of the foregoing assertions, I now pro- duce twenty-four bottles as samples, containing twelve dif- ferent sorts of fruit, viz. apricots, rhubarb, gooseberries, currants, raspberries, cherries, plums, Orleans plums, egg plums, damsons, Siberian crab3*, and green-gages — which have all been preserved in the manner above described.
In order to diversify the degree of heat, and time of con- tinuance over the fire, 1 have done some in one hundred and ninety degrees, and continued them in it for three quarters of an hour, from which experiments it is evident that the heat is too powerful, and the time too long, as the fruit by that degree and continuance is rendered nearly to a pulpf. In the summer of 1807 I preserved ninety- five bottles of fruit, the expense of which (exclusive of bottler and corks) was l/. 9s. 5\d.; but having some fruit left, it will not be right to judge them at a higher rate than lZ. 9s. ; and allowing 5s. for the extra coals consumed in conse- quence of my not having a conveniency of doing more than seven or eight at a time, and this being done at fourteen different times, it will amount to \l. 145. the average cost of which is nearly 4\d. per bottle, exclusive of the trouble of attending them ; but if we estimate their value in the winter season, at }s. per bottle, that being in general as low or lower than the market price, they will produce l/. 15.5., but losing one bottle by accident, reduces it to 4.1. 145. leav- ing a net profit of 3/. on ninety-four bottles, being a clear gain of nearly two hundred per cent. Another great ad- vantage resulting from this statement will appear by making it an article of store for shipping, or exportation; and I shall
* Apples and pears may be done for shipping, &c.
f Some ot" these samples of lb07, were done iu ISO and 190 degrees.
H x submit
for House Use or Sea Stores. S13
submit a few ideas tending to promote such a beneficial ob- ject by doing it in large quantities ; for which purpose suf- ficiently extensive premises must be fitted up, with a proper number of shelves, one above another, at a distance of about five inches. j
The vessel for scalding the fruit in, should be a long wooden trough of six, eight, or ten feet in length, two or three in breadth, and one in depth, fitted with laths across to keep the bottles upright, and from falling against one another ; this trough of water to have the beat communi- cated to it by steam, through a pipe from a closed boiler at a little distance. The boiling water wanted to fill the bottles with, may be conveyed through a pipe and cock over the trough, by which arrangement, many hundreds of bottle* might be done in a short time. It may be prudent to ob- serve that this idea' is only speculative, not having been ac- tually practised, but at the same time seems to carry with it a great probability of success, and worthy the experi- ment.
ft remains now that I state some reason or object for troubling the Society, whom I have taken the liberty to ad- dress, with these communications. The first is a desire of publicity, sanctioned by their investigation of the experi- ments made for preserving fruit without sugar, thereby les- sening the expense attending an object of so much public benefit and utility. The second arises from a personal or private consideration ; but on this subject I shall only ob- serve, that I wish to throw myself entirely on that protec- tion which has ever characterized the liberality of the Society; and that I shall feel highly honoured if they conceive what I have communicated deserving any mark of their favour. I am, Gentlemen,
Your most obedient humble servant,
Wood Street, London, THOMAS SaPDINGTON.
January 1, 1808. f
To the Society of Arts, &c.
O 3 XXXVI. Me-
[ 214 ]
XXXVI. Method of raising large Stones out of the Earth. By Mr. Robert Richardson, of Kesivicft, in Cum* herlana)*.
GENTLEMEN,
I, Robert Richardson, of Keswick, in the parish of Crosthwaite, and county of Cumberland, beg leave to in- form you, that I have found out a method of taking large self-stones out of the ground in a very expeditious manner, and that by this means two men will take as many stones out of the ground in one day, as would require twelve men in the usual way of blasting, and afterwards using large levers, &c.
Where stones of from two to four tons each are to be taken up, two men will raise as many as twenty men in the usual way. The work is done by the power of a tackle, but by my method of fixing the tackle to the top of the stone, by the plug which T have invented, it will hold till the stone is pulled out of the ground, and laid upon the surface, or upon a carriage, if required, all which can be done in a very little time.
Stones of four tops weight, or upwards, may be taken out of the ground within the time of five or ten minutes, by two men, without any earth or soi! being previously taken from around them, or without any digging with hacks or spades. J. C. Curwen, esq., of Workington, has seen and approved of my performance with this invention, and if the Society should think it deserving of a premium, it would ever be gratefully acknowledged by,
Gentlemen, your most obedient humble servant,
Robert Richardson.
Keswick, Feb. 8, 1808.
To the Society of Arts, &c.
PEAR SIR,
I cannot suffer Mr. Richardson's letter to be sent to the
* From Transactions of the Society for the Encouragement of 'Arts, Mannfac-
tures, and Commerce, for 1808. The silver medal of the Society was voted
to the inventor, and one of the implements is preserved in the Society's Re- pository.
Society
Method of raising large Stones out of the Earth. £15
Society without adding a few lines concerning it. I can bear ample testimony to the ease with which the largest self- stones are lifted by his method. I have s?en one upwards of five tons lifted by four men. One of the plugs is sent for the inspection of the Society. There is no difficulty in cutting the hole to receive it, the only care is not to make it too large. It is difficult to explain the theory of its action ; the least stroke laterally disengages the stone. In many situations it is likely to be of great use, not only in drawing stones out of the ground, but in ^making, weirs and em- bankments, where the stones are only to be lifted a moderate height.
One of my farmers in Westmoreland has made great use of one, and speaks of it in high terms. I have exhibited it to' numbers of persons, who could not believe its power till they saw it tried.
Mr. Richardson submits its examination to the Society, and I conceive it will be very useful and beneficial in cases of new inclosures of land. I dp not think it would answer for soft stones, or be safe to use for raising stones in buildings, it being so easily disengaged by any lateral blow. By adding wheels to the tackle machine, or having it upon a sledge, a great deal of time and trouble would be avoided. I purpose to employ this method next summer in making an embank- ment against the sea; the facility it will give in raising and removing large stones, will expedite the work greatly. If any further certificates of the performance of this phi? be required by the Society, T will with pleasure transmit them to you. I will answer for it§ extracting any stone not ex- ceeding five tons weight out of the ground, without any previous moving of the earth ; and it is of importance to preserve large stones entire.
I am, with respect, dear sir,
your obedient humble servant,
Workington Hill, J, Q. ClJRWEN,
Feb! 19, 1S08.
To C. Taylor, M.D. Sec.
0 4 SIR,
216 Method of raising large Stones out of the Earth,
STR,
I am favoured with your letter, desiring; my opinion of the utility of the iron plug invented by Robert Richardson, of Keswick. That which I use is about six inches long, and one inch and a quarter in diameter ; it requires a hole of its owp size, only two inches deep ; the plug is to be driven in a little short of the bottom, and will raise a stone of six or eight tons, with the assistance of three men, in the course often minutes after the hole is prepared ; and I do not hesitate to say, that three men, thus furnished, will clear the ground of large stones in less time, and more effectually, than twelve men by any other method yet come to my knowledge. The plug should be made of good beaten iron. The simplicity and cheapness of the whole apparatus is a great object, as a good plug of the size I use will only cost two shillings and sixpence. I am fully of opinion, that by adding more and stronger ropes and pulleys, wotU might be done by it to an amazing extent. I have reaped great ad- vantage in my farm from the aid of the iron plug, and. in justice to the inventor, am happy in thus vouching for its extreme usefulness. Several of my respectable neighbours have experienced the aid and benefit of the above instru- ment, and will voljcIi, if required, for the truth of the above statement. I am, sir,
your truly obedient servant,
lip .pert Wright.
Rose Gill Hall, near Shap, Westmoreland, May 9, 1808.
To C. Taylor, M.D. Sec.
Reference to the Engraving of Mr. Richardson's Invention for raising large Stones out of' the Earth. See Plate VI. Figs. 1, 2, 3, and 4.
Fig. 1, K, shows the upper part of a stone nearly buried in the earth, having a hole made in it three inches and a half deep, and one inch in diameter, by means of a miner*s jumper ; the cylindrical tail of the plug a, figs. 2, 3, and 4, which is of the same size, is driven fast into it, by means of a hammer applied upon the head of the plug at G. This
Description of an Apparatus, Zjfc. 217
plug, in its whole length, is nine inches, and has a hole made in its broad part H^ through which the oval iron ring B passes easily, and on which the plug can move backwards and forwards, when the ring is hung upon the hook of the lower pulley block of the lifting tackle. CCCC represent the four leg?, or frame-work of the quadrangle , D a five-fold tackle, with blocks ten inches in diameter; Ea roller seven inches in diameter, turned by two long iron levers bb; the handle I is used as a safeguard, and to assist to regulate the power of the levers. In fig. 1, the plug A is shown fixed in the stone K, ready to draw it out of the ground, by means of the lifting tackle.
N. B. The hinder legs of the quadrangle are made to close in between the fore legs, for the convenience of carnage.
XXXVII. Description of on Apparatus for making Car- bonated Hydrogen Gas from Pit Coal, for the Purpose of lighting Factories therewith. By Air. Samuel Clegg,
of Manchester*.
DEAR SIE,
VV hen your son was in Manchester, he called to see my nephew's, Samuel Clegg's, improved gas lights, and was desirous to have a plan of his method, which my nephew promised to him, and I undertook to get it conveyed to you. I have, accordingly, taken the opportunity of sending to the Society of Arts, &x., a plan and explanation of his ap- paratus.
He lighted a large factory in Yorkshire some years ago upon this principle, and has since lighted some buildings in this neighbourhood, and I believe he is the first person who succeeded in rendering these lights free from the offensive smell which generally accompanies them. My nephew served an apprenticeship to Messrs. Boulton and Watt, of Jiirmingham, in the steam-engine business, in which he is
* From Transactions of the Society for the. Encouragement nf Arts, Manufac- ture, and Commerce, for 180S. The silver ruedU of the Society was voted
to the author.
now
218 Description of an Apparatus for making
now engaged here on his own account, and has made con- siderable improvements in their construction.
I remain, dear sir, your most obedient servant,
Asil WORTH CLEGG.
■ Manchester, May 18, 1808.
To C. Taylor, M.D. Sec.
SIR,
Your esteemed favour I have received, and, according to your request, have sent you a fuller explanation of the ga- zometer and lamp, accompanied with further drawings.
A gazometer, containing seven hundred cubical feet of gas, weighs about twenty hundred weight, and costs about two pounds ten shillings the hundred weight.
The whole of an apparatus complete, capable of support* ing forty lamps for four hours, each lamp affording light equal to ten candles of eight in the pound, will cost about two hundred and fifty pounds. Each lamp consumes six cubical feet of gas per hour. I am happy to find that the Society have honoured my communications with their at- tention, and T remain, with great respect,
Sir, your most obedient servant,
S. Clegg.
Manchester, Aug. 12, 1808.
To C. Taylor, M.D. Sec.
Reference to Mr. S. Clegg's improved Apparatus for ex- tracting Carbonated Hydrogen Gas from Pit Coal. See Plate V. Figs, 1, 2, 3, 4, 5, and 6,
In fig. 1, A shows the cast iron retort, into which are put the coals intended to be decomposed by means of a fire underneath it, the heat of which surrounds every part of it, excepting the mouth or part by which the coals are intro- duced. The lid or iron plate B> which covers the mouth of the retort, is ground on air tight, and fastened by means of a screw in the centre ; C is a shield or saddle of cast iron, to preserve the retort from being injured by the intensity of the fire underneath it, and to cause it to be heated more uni- formly. DDD represents the cast iron pipe which con- veys
Carhov at cd Hydrogen Gas from Pit Coal. 21 ^
veys all the volatile products of the coal to the refrigeratory of cast iron Ef in which the tar, &c, extracted from the coal is deposited, and from whence they can be pumped out by means of the copper pipe F. G is the pipe which con- veys the gas to the top of the cylindrical vessel or receiver H ; this receiver is air tight at the top, and consequently the gas displaces the water in the vessel H, to a level with the small holes, where the gas is suffered to escape and rise through the water of the well 2, into the large gazometer K. The use of the vessel H is pointed out as follows, viz. If the pipe G reached all through the wate-\ without passing into the vessel H, the gas would not be rendered pure or washed ; and if part of the pipe did not rise above the water, the water would have free communication with the tar, be- sides exposing the retort ^/toa very great pressure, so as to endanger its bursting when red hot. This vessel or receiver H, in a large apparatus, is about eighteen inches diameter, and two feet long; the quantity of gas, therefore, which it contains, is sufficient to fill the pipes and retort when cool, and prevents the pipe G from acting as a syphon, and ex- poses the gas to the water without endangering the retort.
When the operation begins, the upper part of the cylin- drical gazometer K, fig. 1, made of wrought iron plates, is sunk down nearly to a level with the top of the circular well 7, and is consequently nearly filled with water, but it rises gradually as the gas enters it and displaces the water; the two weights LL suspended over pulleys by chains keep jt steady and prevent its turning round, otherwise the lower stays M of the gazometer would come into contact with the vessel H. There are two sets of these stays, one shown at M, and the other at N.
There is also an iron pipe 0 made fast in the centre of the gazometer by means of the stays, which slides over the upright pipe P, by which contrivance the gazometer is kept firm and steady , when out of the well ; it likewise prevents the gas from getting into the cast iron pipe P, and the cop- per pipe P. any where but through small holes made in the pipe 0 at S at the top of the gazometer, where the gas is perfectly transparent and fit for use.
The
220 Description of an Apparatus, &c.
The pure gas enters the tube 0 at the small holes made in its top at S, and passes on through the tubes P and R to the lamps, where it is consumed and burnt.
The seams of the gazometer are luted to make them air tight, and the whole well painted inside and out, to preserve it from rust.
Fig. 2 shows a horizontal section of the lower hoop of the gazometer K at the part M, with its stays or arms, and the manner in which the iron pipe C, before described at fig. 1, sliding on the tube P, passes through the ring in the centre of the hoop ; a horizontal section of the receiver H appears therein.
Fig. 5 shows a section of one of the gas lamps ; the space between the outer tube T and the inner tube V, is to be filled with gas supplied by the pipe 7?, shown in fig. 1, where a stop cock is inserted for adjusting the flame, which gas passes through a number of small holes made in the outer edge of a circular plate shown at fig, 6, which unites the tubes Tand V-aX their tops. V\§ the inner tube which conveys the atmospheric air into the centre of the flame ; the upper part of this tube is made conical, or widening ouU wards, to join a circular plate with holes rn it, a horizontal view of which is shown at fig. 6. IV is a button, which can be placed at a small distance above the mouth of the lamp, and its use is to convey, in an expanded manner, all the air which rises through this tube to the inner surface of the flame, which assists the combustion very much ; this button may be set at any convenient distance above the tube* of the lamp, as it slides in the cross bars XX, by which it is supported in the inner tube.
A current of air also passes between the glass tube or chim- ney and the outer tube T, through holes made in the bottom of the glass-holder, as in Argand's lamps; this surrounds the flame, and completes its combustion, as explained by the view, fig. 3, and section, fig. 4, which have a glass upon each. ZZZZ, figs. 3, 4, 5, and 6, show the tube through which the lamp is supplied with gas from the pipe R, fig. 1.
XXXVIII. Re-
[ 221 ]
XXXVIII. Report of Dr. M. Garthshore and Patrick Colquhoun, Esq., to the Society for lettering the Con- dition of the Poor , to whom it was submitted to consider the Expediency and Practicability of establishing an Ex- perimental Dispe?isary in the Metropolis, comprising in its Structure a Dietetic Regimen for debilitated Patients.
Xjkfore any accurate opinion can be formed of the utility, necessity, and practicability, of adding a dietetic to the me- dicines generally administered to the poor at the different dispensaries in the metropolis, it may be useful to detail a number of prominent facts, which either bear directly or collaterally on this subject, and which are necessary to assist the mind in forming a correct judgment.
According to the parliamentary returns of the year 1803, it appears that the number of poor persons relieved in that year in the metropolis, comprehending all the parishes within the bills of mortality, besides Marylebone, St. Pan- eras, Paddington, Kensington, Chelsea, and Islington, (in- cluding a population, according to the parliamentary re- turns of 1801, amounting in the whole to 846,845 persons,) was 86,120.
Of these 86,120 poor persons relieved,
14,746 were maintained in sixty workhouses, at theyearly expenseof 14.1.8s. 3\d. per head. C 2 1,97 7 vvere relieved out of work- •^0^1^) houses, at the expense of about i2 15 0
*!;?J-'ti*d a | 33,187 were occasionally relieved — at
the expense of about - 15 0 16,310 were relieved, not being pa- rishioners, supposed vagrants, 0 2 0
year.
Total 86,120
The number of children under fourteen years of age are nearly equal to the adults who have received relief. The workhouses (sixty in number) % are generally full during the winter months, and the greatest number that can be ac- commodated
222 On Lettering ike Condition of the Poor.
commodated docs not exceed 17,000 men, women, anJ children.
The number of distressed objects who do not receive any parish relief', but who are supposed, in many instances, to require it as much a? those who are relieved, may be esti- mated at about 20,000 men, women, and children.
It will be seen from the above abstracts, that the perma- nent out- door relief seldom averages above 25. to 25. 6d. per week, while the occasional relief is infinitely less, which is barely sufficient to pay the weekly rent of a miserable half- furnished lodging.
It will also be seen, that many thousand cases may occur, wherehalf- famished families cannot obtain an asylum in their parish workhouse for want of room. And that the propor- tion of those who are relieved at their own dwellings, is nearly four to one.
Hence it follows as a clear proposition, that there ever has been, and always must be, a very large proportion of the poor of the metropolis, who can derive no benefit from the maintenance afforded in the parish workhouse : and that the pittance allowed in money, can afford little for food, where a family is broke down by sickness, and their only property (the labour of their hands) no longer effectual or productive. Hence, in such cases, the pawnbroker assists in filling up the chasm until their little all is exhausted, and they are not only without food, but also deprived of their apparel and bed clothes.
To relieve this numerous class, who are subject to so many casualties, reducing them to a state of extreme indi- gence, benevolent individuals have founded hospitals and dispensaries in different parts of the metropolis ; but many of the hospitals arc ill endowed; and from a deficiency of funds, they arc not adequate to the relicfof one-tenth part of the patients who would be glad to become inmates during sickness and disease.
The dispensaries are more numerous. It appears from an authentic return from thirteen of these establishments in different parts' of the metropolis, that, in the course of the year 1803, medicines were dispensed to 28,134 patients, at
the
Cn bettering the Condition of the Poor. 223
the expense of about 1200 to 1500/. for drugs, and perhaps about 2000/. for house-rent, taxes, salaries, and other ex- penses— in the whole, between three and four thousand pounds a year. These nearly comprehend all the dispen- saries in the metropolis.
But it requires little investigation to convince the mind, that drugs alone will not restore an enfeebled body to health, where the cause of the disease originated in the want of nourishing diet. On the contrary, they are often pernicious, unless accompanied by a dietetic regimen, which is out of the reach of a considerable proportion of those distressed objects who become patients to the different dispensaries. There, every medicine is to be found, but that alone whiclv in many cases is to effect a cure. Their bodies are wasted, and must be restored by nourishing food. Their recovery depends on this ; but it is not attainable — it is apt to be found in their miserable dwellings ; and the workhouse is shut against them — it is already full; and the hospitals are also inaccessible.
That this evil exists, in a great degree, in the metropolis, must be evident from the state of the poor, which has been already explained, and which rests on the solid foundation of parliamentary documents.
That such also is the state of many patients who are re- lieved at dispensaries, every candid medical man who attends these dispensaries will admit. If the evil therefore exists, and if its magnitude is as great as the facts stated afford the . strongest grounds to suppose, a question will arise among those who are benevolently employed in their laudable en- deavours to better the condition of the poor in the metropo- lis— In what way a remedy can be applied? — a remedy which shall restore parents to their families, and children to their parents, who must otherwise drop into the grave.
In suggesting new and untried objects, difficulties natu- rally occur to the mind, which often vanish on a patient in- vestigation ; and such it is earnestly hoped will be the case on the present occasion.
The dispensaries at present administer those medicines
whicluire most generally applicable to that part of the coin-
j G m unity
£-1 On lettering the Condition of the Poor*
munily who are in easy ci re u instances. To adapt them to the poor, there ought to be superadded, a certain moderate proportion of spirits for cordials — strong porter — soups — and also flannel waistcoats and shifts and shirts. These will avail more in manv disorders arising from scantv food, than all the materia medica. Nor will the difficulty of preparing and dispensing these auxiliaries be so great, or the expense so formidable, as may appear to those who have not minutely investigated the subject in detail. The dietetic is proposed to be dispensed as medicine, not as food. It will make a part of the physician's and surgeon's prescription, where, upon due inquiry, and according to the nature of the case, such auxiliary aid, together with the flannel garments, are found to be necessary to give effect to the drugs. Both are to be dispensed in small portions, and only to those who actually require such aid, and cannot otherwise obtain it. The soup to be prepared and taken in the kitchen of the dispensary, on the order of the medical attendant, only in extreme cases. The dietetic is capable of being so syste- matized as to prevent not only the shadow of abuse, but also at no additional expense of servants ; and the materials com- posing it, and all the other auxiliaries will cost infinitely less than can be supposed at first view, as will appear from the following statement :
Estimate of the Expense of an Experimental Dispensary, with the Dietetic Auxiliary.
House rent and taxes -
Apothecaries' salary -
Servants' wages, 8cc. -
Coals and candles -
Drugs ----.-
Spirits for cordials - - -
Malt liquor of the best quality
Meat, consisting of legs and shins, and clods and stickings, for soup
Potatoes for potatoe soup, &c.; vegeta- bles, barley, &x., about
Flannel waistcoats and shirts and shifts
The
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£ |
100 0 0 |
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80 0 0 |
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- |
40 0 0 |
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- |
40 0 0 |
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|
- |
70 0 0 |
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- |
25 0 0 |
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>45 |
0 0 |
40 0 0 |
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15 |
0 0 |
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25 |
0 0 |
85 0 0 |
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^4S0 0 0 |
On lettering the Condition of the Poor, 223
The usual expense of medicines is here reduced, because in 'many instances the dietetic will be substituted for drugs, which would otherwise be administered, producing at pre- sent little or no benefit to debilitated patients, whose disor- ders have been chiefly occasioned by deficient nourish- ment.
The soups to be of two kinds : — Beef tea for debilitated pa- tients ; and a stronger broth mixed with vegetable substances for those who are in a state of convalescence, and can bear a stronger diet. Not more than a pint of any of the two ?oups'\vill probably be ordered by the physician or surgeon to any one patient, which must be taken in the common kitchen of the dispensary. The cost of a pint of either kind of soup cannot be estimated at more than twopence, (in- cluding the expense of fuel,) and this to be given in lieu of a composition of medicine which would probably cost double that sum. Two common boilers, such as are used in pri- vate families, will be sufficient to prepare the soups for each day's delivery ; and admitting that twenty patients (although an opinion prevails that ten will be the utmost number) re- quire soup, the whole quantity to be prepared on any one day will not exceed four gallons, and the total expense will be 3s. 4d. Other patients may require strong porter — a pint of which (in a pint bottle) is to be delivered to the patient on the prescription of the physician or surgeon ; and supposing ten pints to be issued in one day, the expense will not ex- ceed 2s. 6d. — the patient to bring back the bottle to be again filled, or not, according to the prescription of the medical gentlemen. It has already been observed, that the common kitchen of the house will be amply sufficient for every pur- pose; and the design is capable of being so systematized as to prevent the possibility of abuse. The labour to the cook- maid will be next to nothing. The spirits will be made up in cordials, by the direction of the physicians, and admi- nistered to such patients as may require this species of as- sistance in order to promote their recovery. It will be de- livered in the disguised state of a drug, to be taken at dif- ferent times, under circumstances where no abuse can pos- sibly take place, at the residence of the patients.
Vol. 33. No. 131. March 180Q. P Supposing
It 6 On lettering the Condition of the Poor.
Supposing 4,000 pints of soup to be dispensed
in a year, at 2d. a pint - «s£\33 6 & 3,000 pints of strong porter dispensed
in a year, at 3d. a pint - 37 10 O
• . Total expenses ^70 16&
Considering this limited dietetic in the light of new and more appropriate medicines, nothing in the general eeconomy of the system can be supposed to experience any change. One prescription* from the physician or surgeon* goes to the apothecary, and another to the kitchen. Nothing is in the smallest degree disturbed, and the utmost regularity would pa-vail r
Under a self-evident presumption, that fchb dietetic >s to save the lives of many individuals, who would otherwise sink under their complaints ; and, by thus giving effect to the power of the medicines, preserve many useful lives, — it is scarcely possible for the human mind to devise any scheme where so much good is likely to be done at so small an ex- pense. Nor is there any way in which the condition of the sick poor in the metropolis can be so much improved; since the success of an experimental dispensary, with a dietetic auxiliary, upon the plan now proposed, (as to which there, ran be no doubt,) would be the means of extending the same [tfto to the other dispensaries in the metropolis; and thereby ctmi ribute to the recovery of many hundred poor persons in the course of a year, to whom, for want of a small portion of nourishing food applied at a critical mo- ment, medicines can be of little use in effecting a cure.
For these and other reasons which could be adduced, the garters are decidedly of opinion, that an experimental dis- pensary, upon the plan now proposed, would prove an in- calculable benefit to the poor, and that it highly merits the patronage and countenance, not only of this society, but of
ihe public at large,
M. Garthshorr.
P. CotfcUHOUN.
london, Fet>. 3, 190&
At
On the Vineyards and Wines of Champagne. 227
At a Meeting of the Committee of the Society for Bettering the Condition of the Poor, held at Mr. Hatchard's, Pic- cadilly, on Friday the 3d of February, 1 809,
THE LORD BISHOP OP DURHAM IN THE CHAIR,
, Resolved, — That this meeting do unanimously approve of the suggestions offered in this Report, and will afford every counteuance and assistance in promoting the experimental dispensary with an auxiliary dietetic, upon the plan which has been proposed.
Resolved, — That the said Report be forthwith printed, and generally circulated among t Lie members of this society, in the expectation that their aid and countenance will be af- forded in carrying the design into effect.
Resolved, — That one hundred copies of the said Report be sent to each of the dispensaries in the metropolis.
Resolved* — That one hundred copies of this Report be presented to Dr. Herdman, of Old Broad Street, London, who first suggested and elucidated the plan for improving dispensaries by a dietetic auxiliary, and the medical treat- ment of the diseased poor, in a printed letter addressed to the president, vice-presidents, and the other members of the committee of this society.
S. Dunelm, President.
XXXTX. Memoir upon the Vineyards and Wines of Cham- pagne in France : Written in unstoerio certain Queries cir- culated by M. Chaptal. By M. Germon, of Epernay.
[Coaclu-ded from p. 150.]
Is Graf ling attended with Advantage?
£ xfty years ago they used to graft the vines on the moun- tains, and they generally obtained very fine vines with large fruit. This plan has now been abandoned, because it has been discovered that a grafted vine dues not last so long as an ungrafted one, and the grafted vine is always more ten- der and delicate 5 besides^ it produces a poorer kind of wine.
P 2 Horn
228 Memoir on the Vineyards and Wines
How many Dressings are given to the Vines previous to tkt Vintage P
The first dressing, which is called hecherie (hoeing), is given immediately after the frosts have disappeared.
In general, as soon as the nud of the vine makes its ap- pearance the women proceed to prime, and the men follow with the first dressing. This is a pernicious system ; but the prejudices of the proprietors have not yet given way to the counsels of men of science.
The vines are pruned at the same time with the first hoe- ing : but this method is not practis-ed in the Marne district, where they prune subsequently to the hoeing : it frequently, however, saves the primings from the effects of the frost, and presents a resource to the proprietor if the vines have suffered from this accident.
Two other dressings are afterwards given, one in June and the other in August; but some proprietors, who are jealous of the good qualities of their vines, give them a third dress- ing in September.
What are the Processes employed in gathering and pressing the Produce of the Vintage P In order to make red wine, — when the fruit is perfectly ripe, the black grapes only are carefully picked and gather- ed. The white grapes are laid aside, as well as those red ones which are not ripe ; and these are afterwards made into wine of an inferior quality. The ripe red fruit, when thus separated, is put into panniers, or small wooden boxes called larillets or cuvelcts, and conveyed on the backs of beasts of burden to the pressing-place : here they are pressed by small portions at a time, and the juice then put into a tub to ferment. In performing this operation some proprietors employ an utensil called a martyr, which is very, useful. This is an oblong coffer, less than the diameter of the fer- menting-tub, and about a foot or eighteen inches high. This coffer rests upon beams placed across the fermenting- tub, and its bottom and*sides are pierced with holes in such a manner as to allow the expressed juice of the grapes to flow through into the tub.
How
of Champagne in France. 220
How long is the Wine allowed to ferment ?
It would be difficult to fix any precise time for the dura- tion of the fermentation ; this depends entirely upon the na- ture and maturity of the fruit, and upon the influence of the atmospheric air. Grapes gathered in the morning will more slowly go into fermentatioir 4han those which have been gathered afternoon-day in fine weather: — mists, rains and hoar-frosts, ali retard fermentation more or less.
In some years, three or four days are sufficient for pro- ducing a fermentation sufficient for preparing the fruit for the press : — in other years, ten, fifteen, and even twenty days- are required. - '
By what Sign is it ascertained that the Fruit has attained a proper Degree of Fermentation P
We cannot assign any certain symptoms that the wine has sufficiently fermented, a6 the period proper for placing the bruised fruit into the presses depends upon various causes ; upon the pleasure and experience of the proprie- tor, and upon the quality and colour which he wishes to give to his wine. Some place the fruit in the press at the strongest degree of fermentation, and others when it has slackened.
After the fermentation begins, in order to hasten it, they squeeze down the fruit in such a manner as to keep the must always uppermost; poles armed with spikes are used for this purpose ; or, what is better, some strong workmen de- scend into the vat and tread down the fruit : the fermenta- tion thus becomes more equal and more general ; and when it has proceeded far enough,, the must is carried to the press and the wine is made.
In ordinary ye,ars, when a lighted candle cannot be held over the tub without going out \ when the grapes and husks ascend to the ton, not withstanding their being repeatedly pressed down ; when the must undergoes a kind of ebulli- tion; and lastly, when the colouring particles are sufficiently decomposed to satisfy the wishes of the proprietor, — it would &e dangerous to push the fermentation any further, as in
P 3 that
230 Memoir on the Vineyards and Wines
that case the wine might assume a dry and hard taste which even time could not correct, particularly in Champagne wines, which are prized on account of their pleasantness and lightness. The most consummate experience is some-' times unsuccessful ia the above operations, and there has been no instrument yet invented which can be depended upon.
Js it advantageous to mix the extractive Liquor of the Tul& with that which is produced by pressing ?
This may be answered in the affirmative, with respect to the whole of Champagne; — and it is very advantageous for the following reasons :
1st, The wine made from the tub would be paler in co- lour and more delicate than that which is expressed from the husks.
2dly, The wine which came from the press only, would be harder, stronger, and redder, than the other ; so that from the same tub we should certainly have two different kinds of wine : — The mixing of them is therefore indicated by expe- rience, and it is at all times necessary to have wines of an equal quality.
Is it ad',*antageou$ to Iruise the Stones of the Grapes f
This operation depends upon the season, and upon th^ ripeness and nature of the fruit. When the fruit is small and the stone large, or when the fruit has not acquired all ;ts maturity, the stones should be bruised,
When the fruit is full and well grown, when the season has been rather dry than humid, this operation may bo omitted. It has been ascertained, however, that the strong and rough taste of the stones is necessary j as one of the, constituent parts p,f wine.
To what Occidents are Red Wines Halle when m ihe Casks 2
The accidents to which red wines are liable, are yellow- ness, muddiness, and a wormwood taste. These accidents happen when the wines ajre kept in badly-aired cellars, or
when
$f 'Champagne in France. 23 i
when the fruit has been damaged during the vintage season by frosts or continual rains.
How are the Red Wines managed ?
When the <red wine which comes out of the tub, and thai which has been expressed from the husks, are well mixed together in a vat procured for the purpose, the whole is poured into new puncheons previously rmced Svitb hot wa- ter; hut they are not fiitad at once, because the wine always ferments for a few days longer : — as the fermentation ceased they are filled and bunged up, leaving a small spiggot in the bung in order to allow the gas to pass out : when the fer- mentation has entirely ceased the puncheon is hermetically closed.
About the end of December, and if possible in dry wea- ther, the wine is drawn off and free4 frona the greatest part of the lees.
About the middle of May, before the warm season com- mences, the wine is again drawn off clear. Before putting the puncheons into the cellar they are furnished with new hoops, where they are kept during the summer, or till they are sold, otherwise their contents would be spoiled.
What is the Method of clarifying Red Wines P
This consists m drawing off the wine a third time. The whites of five or six fresh eggs are diluted in a chopih of water ; and this quantity is sufficient for each piece or pun- cheon containing 240 bottles.
There are only 200 bottles in a puncheon of white wine.
The whites of eggs are well beaten up and then thrown into the puncheon, the contents of which are then briskly stirred up by a cleft stick.
This operation is performed previous to bottling the wins or sending it off to a market.
At what Age should Red Wines he bottled ? In general, the red wines of Haute Montagne are bottled in the month of November succeeding the vintage, i. e, thirteen months afterwards. This season of the year is fixed
P 4 upon
232 Memoir on the Vineyards and Wines
upon because all germination has ceased, and Nature is in a state of perfect repose ; thereby all fermentation is avoided ; and red wines may therefore be safely bottled from the first of October until the end of December: at any other season great inconveniences would arise; for I know of nothing worse than red wine bottled in spring time; it retains a slight degree of fermentation, and is very disagreeable to the taste.
There are some excellent and generous wines which can remain three or four years on their lees : of this description are the wines of St. Thierry.
How long will Red Wines keep in Bottles P The more body and spirit the wine has, the better is it preserved in bottles : the more tender, delicate, and light it is, the more difficultly is it kept.
This is the reason why the wines of Mailly, Chiny, Che- nay, and Hermonville, keep worse than those of Verzenay, Bouzy, and Verzy; and these last worse than those of St. Thierry, To conclude: — We may safely venture to say, that the best red wines of Haute Montagne will keep in good cellars for six, eight, ten, and twelve years.
What Degree of Temperature, according to Reaumur's Ther- mometer, ought the Cellars to have ? The cellars in Champagne are from 25 to 40 feet in depth, particularly those which are dug in beds of chalk, and in which it is necessary to dig low, in order to obtain such a solidity of earth above, as to render an arch unnecessary. It results from experiments made by Messrs. Dubois, mer- chants at Rheims, that several good thermometers placed in various situations in their cellars, always marked five degrees below the temperature of the atmosphere. The va-r nations between winter and summer were not half a degree, and could not be noted.
What is the Cost of an Acre of Vineyard? ..
FIRST CLASS.
Livrcs.
In Haute Montagne - 2000 Tn Basse Montague - 1000
In St. Thierry " - - yoo
SECOND
of Champagne in France. «33
SECOND CLASS.
Livr'es.
In Haute Montagne - ooo In Basse Montagne - 600
In St. Thierry ■ - - 300 The convent lands, and what is called Clos St. Thierry, are not taken into this computation.
What is the annual Expense of Cultivating an Acre of Vineyard, including the Expense of Vintage and of Priming f
Livreu.
To the vine-dresser 50
Props - - - - 18
Mending them, and carriage, &c. 40
Prunings aiid contributions - 24
Four puncheons - 40
Expense of vintage - - 28
200
General Observations.
We have only mentioned the culture of vines in general, without detailing those of the high and low grounds sepa- rately. There are many vineyards, however, and particu- larly in St. Thierry, where the greater part of the vines is always raised to the height of about rive feet, and supported by props of oak, six feet high, and an inch in diameter; This kind of vine can only answer in strong and vigorous ground.
The difference between the culture of the high and low vineyards, consists in the shaping, tyeing, and pruning.
1st, Shaping consists in choosing from the sucker the best stalk, in preference to others which are cut off, and all the small collateral shoots are lopped off.
edly, The tyeing is effected when the sap is most abundant, and the bud already developed: the above single stalk is bent like a hoop, and tied to the prop in two or three places.
3dly, Pruning consists in reinserting into the earth, and
into small and long holes, every ten or fifteen years, the
old sucker, upon which three or four stalks are left, which
are also buried in the earth ; and they send out an excellent
, 3 plant
334 On tlie. Affinity existing let ween
plant for the ensuing year. This operation is called ravalle- tnenty and is very different from the pruning practised in the department of the Mame.
An intelligent proprietor, who has a large extent of vine- yard, should bury some vines (ravaller) every year, in order to have a sure and constant supply of plants for replanting.
The methods of treatment are in every respect the same with high and low plants.
XL. On the Affinity existing between Oxides of Carbon and Iron. By David Mushet, Esq.
In my late communications to the Philosophical Magazine, a number of experiments were adduced to exhibit the uni- versal diffusion of carbon, and to convey a tolerably correct idea in what proportions it enters into the composition of animal, mineral, and vegetable substances.
The affinity that exists mutually betwixt iron and carbon is every day manifested as the basis of one of our greatest na- tional manufactures : in particular, in the various modifi- cations of cast iron, steel, plumbago, &c.
Any inquiry that has for its object the investigation of jhose means, and of their peculiar modes of formation, to which we exclusively owe the exisience of the most widely diffused and most useful metal that has hitherto been known in civilized society, commands attention, not only as a matter of curiosity, but as an object of die highest impor- tance.
The natural mutual affinity of iron and carbon is such, that they may be reciprocally used as tests and agents of each others existence respectively ; and upon this principle, chiefly, the experiments which are to follow were performed.
The first object to be ascertained, in pursuing this investi- gation, was the nature of oxide of carbon, whether in the State of charcoal, coke, plumbago, &c. ; and wherein, and jn what, it differed from the matter of carbon that existed naturally in the substances from which these were obtained.
If any two oxides of carbon were taken similarly com- pounded
Oxides of Carlon and I Iron, 235
pounded as to the alloy of foreign matter, and employed un- der the same circumstances, to revive equal quantities of the- same metallic oxide, Would in not be just to infer, that if the quantities of metal were equal, so were the qualities of the oxide ; and the reverse if a different result were obtained? And does it not appear equally fair to deduce; that where the greatest quantity of metal is revived, the appropriated oxide is of superior quality ? The former deduction holds uni- versally correct; but the latter, if admitted, would often lead into error, particularly where the oxides exist in the state of coal or coke.
I was once of opinion that the carbonating powers of any oxide depended upon the real quantity of combustible mat- ter which it contained ; and that the substance found to yield the largest portion of coal or coke, and to contain the smallest portion of ashes, would, every thing else being alike, revive the greatest quantity of metallic oxide ; or, in other words, would be found to contain the largest quan- tity of pure carbon, or diamond: but upon investigating the nature and properties of a variety of carbonaceous oxides, chiefly obtained by the distillation of pit coal, with a view to fix an unerring list whereby to judge of coal fit for iron making, it was found that not only this conclusion was of itself erroneous, but that, in general, the very reverse of this theory took place. It not only appeared that the car- bonating powers of the oxide depended upon some other cause, remote from the actual quantity of combustible mat- ter, but that the process of distillation, or of coking, sub- jected the oxide to new laws, the very reverse of what at first view ought to have taken place. This, then, was at once attributed to the state of oxidation of the oxide ; and a direct probability inferred, that that coke or coal that revived the greatest quantity of metallic oxide would be the least oxi- dated ; or, in other words, approach more nearly to the state of diamond.
This theory, however plausible, was found incompatible
with practice ; and in the event it was found that the cokf
or coal that became most deoxidated in burning, revived,
under precisely the same circymstances, the least quantity
• . of
S3(> On the Affinity existing between
of metallic oxide : and from the experiments hereafter to be detailed, it will not appear rash to infer, that this in- verse ratio of carbonation proceeded exclusively from an approximation, however remote, to the state of diamond ; arising chiefly from a new and more dense arrangement of the particles of the coal, in consequence of parting with a portion of oxygen.
These experiments were arranged and conducted in the fol- lowing order : — About 50 pounds of oxide of iron were pre- pared, and thoroughly mixed, that there might not exist any variety of quality arising from different preparations. This was kept during the whole series of experiments in the same temperature, that none of the results might be affected by the moisture of the atmosphere. A parcel of hand-made crucibles, all nearly of the same size, prepared from Stour- bridge clay, with ground covers, made so as to form a water- tight joint, were set aside for the experiments. These, from time to time, before the introduction of the mixture, were brought to a red heat : when in this state, the mixture was introduced, the cover was slipped on, and the whole was put directly into the assay furnace. This mode had not only the advantage of facility, but, which in these experiments is absolutely indispensable, prevented the carbonaceous mat- ter introduced from being dissipated by the moisture, which is always contained in the clay when crucibles are put into the furnace in a green state. ,
The proportions of oxide of iron and oxide of carbon, used in the most of these experiments, were oxide of iron 200 grains, of carbon 15 grains.
These were intimately mixed, and put into a square of thin paper containing about five superficial inches of mea- surement, and productive exactly of half a grain of char- coal : this, and 14y grains of the lubstance to be tried, formed the quantity of 15 grains. So that in all these ex- periments there is nearly l-2Qth of carbon of paper united. When the experiments were directed to comparative views betwixt the raw and coked materials, a quantity of the former was used, that would, by accurate experiment, have formed 15 grains of coal, or prepared oxide of carbon. The
paper
Oxides of Cation and Iron. 237
pftper and mixture were with facility introduced into the crucibles respectively, and the immediate introduction of the cover prevented the most minute contact of air, or dis- sipalion of the subject of experiment. The duration of the crucible and degree and management of the heat in the furnace were scrupulously attended to, and many of the ex- periments were repeated three times.
The first class of experiments was with various woods, from which the following were selected :
Experiment I. Charcoal prepared from Walnut, composed cf Oxide of carbon - 96*048 Ashes - - - 3* <J52
100 parts,
15 grains of this oxide and 200 grains of oxide of iron, were subjected to fusion, after being carefully mixed, and the result was a metallic button which weighed 36 grains, (equal to 18 per cent.) from the oxide of iron.
It was found, upon a calculation of what this wood lost in distilling, that 76 grains of raw wood would have- formed 15 grains of the charcoal operated upon. This quantity of wood was therefore rasped dowrr, and, in a similar manner with the former, introduced into the crucible. The result was A metallic button weighing - 49 grains.
Charcoal of the same wood, revived as above, 36 Increase (equal to 6| per cent, or 24} upon the whole,) - - - - - 13
Experhntnt II. Charcoal prepared from Elm, composed of Oxide of carbon - 96*70 Ashes - - - 3-30
100 parts,
15 grains of oxide from elm and 500 grains of oxide of iron, yielded a metallic button weighing 40 grains (equal to 20 per cent.). »* . 75 grains
C3S On the AJjimly existing between
75 grains of the same wood, in the state of raspings, found to he equal to IS grains of prepared coal, being mixed * grains of oxide of iron, they were fused together,
and the result was a metallic button weighing 59 grains. (Equal to 29} per cent, from the oxide of iron.) With the charcoal, the quantity revived was 40
Increase (equal to <j\ per cent.) - It)
Experiment III. Charcoal prepared from Holly,
Composed of oxide of carbon 94- 1 55 Ashes - - 5-848
J 00 parts.
15 grains of this carbon and 200 grains of oxide of iron, yielded by fusion a metallic result that weighed 44 grains. (Equal to 22 per cent.)
7T4 grains of raw holly, being equal to 15 grains of char- coal, and 200 grains of oxide of iron, yielded by fusion A neat metallic button weighing 45 grains. Kevived as above with charcoal 44
Increase (equal to | per cent.) 1
Experiment IV. Charcoal prepared from Scotch Pine, Composed of oxide of carbon Ashes
100 parts.
15 grains of this charcoal and 200 grains of oxide, of iron, being fused together, yielded a metallic button of iron weighing 40 grains, of 20 per cent. 88 grains of raspings of this wood (equal to 15 of charcoal,) and 200 grains of oxide of iron, yielded a button of iron that weighed
34 per cent., or - - 68 grains.
Kevived as above with charcoal 40
Increase (equal lo 14 per cent.) 28
Experiment
Oxides of Carbon and Iron, 23 9
Experiment V. Charcoal prepared from Beech,
Composed of oxide of carbon Ashes
100 parts.
15 grains of charcoal of beech mixed with 200 grains of oxide of iron, yielded by fusion a metallic button of iron weighing 42 grains, (equal to 21 per cent.)
71*5 grains of raspings of this wood, (found equal to 15 grains of carbon,) being mixed with 200 grains of oxide of iron, there resulted from the fusion of this compound a me- tallic button that weighed (= to 27i percent.) 54'5 grains. Revived as above with charcoal 42
Increase (equal to Q\ per cent.) 12*5
Experiment VI. Charcoal prepared from the American Maple-Tree, Composed of oxide of carbon 96*140 Ashes - - 3-860
100 parts,
13 grains of this charcoal and 200 of oxide of iron gave a metallic button weighing 50 grains, (equal to 25 percent.) from the oxide of iron.
76 grains of this wood (equal to 15 grains of charcoal,) and 200 grains of oxide of iron, yielded by fusion a but- ton of iron, weighing (equal to 30 [ per cent.) 61 grains. Revived as above with charcoal 50
Increased, (equal to 5\ per cent.) 1 1
Experiment VII. Charcoal prepared from Spanish Mahogany,
Composed of oxide of carbon 96* 1 54 Ashes - - 3-846
100 parts.
1 5 grains
140 On the Affinity existing between
15 grains of this charcoal with 200 grain? of oxide of iron, gave by fusion a metallic button weighing 40 grains, (equal to 20 per cent.) from the oxide of iron.
bb'b grains of mahogany was found equal to 15 grains of charcoal. This, in the state of small raspings, was mixed with 200 grains of oxide of iron. The result, by fusion was A metallic button weighing 43 grains.
Revived as above with charcoal 40
(i
Increased, (equal to \\ per cent.) ;-»
Experiment VII h Charcoal prepared from Sallow,
Composed of oxide of carbon 93'Sfii Ashes - - (5-135
100 parts,
15 grains of this charcoal mixed with 200 grains of oxide of" iron, gave by fusion a metallic button which was found to weigh 43 grains, (equal to <2\\ ptr cent.)
79 grains of sallow, being found equal to 15 grains of charcoal, this, in the state of raspings, was mixed with 200 grains of oxide of iron. The compound was fused, and the result was A button of iron weighing 6*0 grains. Charcoal revived only - 43
Increase, (equal to 8| percent.) 17
Experiment IX. Charcoal prepared from American Black Beech, Composed of oxide of carbon 95* 1 69
Ashes - - 4-831
100 parts!
15 grains of this charcoal mixed with 200 grains of oxide of iron, yielded by fusion a metallic result weighing 36 grains, (equal to 18 per cent.)
Gy grains of black beech were requisite to form 15 grains of charcoal. These, in the state of raspings, were mixed with
200 grains
Some Circumstances relative to Merino Sheep, 241
200 grains of oxide of iron and fused together, the result w;.s, A metallic button that weighed 48 grains.
Revived with charcoal - 3(3
Increase (equal to G per cent.) 12
[To be continued.]
XLI. Some Circumstances relative to Merino Sheep, chiefly collected from the Spanish Shepherds, ivho attended those of the Flock of Panlar, lately presented to His Majesty by the Government of Spain ; with Particulars respecting that great National Acquisition ; and also respecting the Sheep of the Flock of Negrcte, imported from Spain by His Ma- jesty in the Year 1791*. By Sir Joseph Banks.
Soho Square, Feb. 18, 1S09.
Sir John, J\.t a time like the present, when Spanish wools, though at a price unheard-of in the annals of traffic, still continue to find a market ; thus clearly proving, that their value in the estimation of the consumer is far above any price that has been hitherto offered for them by the manufacturer ; and when we must all agree, that the interruption of our trade with Spain may still continue for some time longer, I trust that a paper written with a view to facilitate the production of this valuable article in the United Kingdom, and to com- municate some information relative to the important present of Merino sheep lately received by our most gracious Sove- reign from the government of Spain, will be interesting to you, sir. I beg the favour of you, in case you shall approve it, to do me the honour of placing it at the disposal of the very useful institution over which you preside with so much advantage to the agricultural interests of this country. I have the honour to be, sir,
Your obedient and faithful humble servant,
Joseph Banks.
Sir John Sinclair, Bart. President «f the Board of Agriculture.
* From Coramunicat'ons to the Board of Agriculture.
Vol. 33. No. 131. March 1809- Q A con-
242 Some Circumstances relative to Merino Sheep.
A considerable part of E-strcmadura., Leon, and the neighbouring provinces of Spain, is appropriated to the main- tenance of the Merino flocks, called py the Spaniards Tra- shumantes, as are also broad green roads, leading from one province to the other, and extensive resting-places, where the sheep are baited on the road. So careful is the police of the country to preserve them -during their journeys from all hazard of disturbance or interruption, that no person, not even a foot passenger, is suffered to travel upon these roads while the sheep are in motion, unless he belongs to the flocks.
The country on which the sheep are depastured, both in the southern and the northern parts, is set out into divi- sions, separated from each other by land-marks only, with- out any kind of fences; each of these is called a Dehesa, and is of a size capable of maintaining a flock of about a thousand sheep ; a greater number, of course, in the south country, where the lambs are reared, and fewer in the north country, where the sheep arrive after the flock has been culled.
Every proprietor must possess as many of these in each province as will maintain his flock. In the temperate sea- son of winter and spring, the flocks remain in Estremadura, and there the ewes bring forth their lambs. in December. As soon as the increasing heats of April and May have scorched up the grass, and rendered the pasturage scanty, they com- mence their march towards the mountains of Leon ; and, after having been shorn on the road, at vast establishments called Esquileos, erected for that purpose, pass their sum- mer .in the elevated country, which supplie-s them with abundance of rich grass ; and they do not leave the moun- tains till the frosts of September begin to damage the herbage.
A flock in the aggregate is called a Cavana : this is divided into as many subdivisions as there are thousands of sheep, belonging to it ; each sheep, besides being sear-marked in the face with a hot iron when young, is branded after every shearing with a broad -pitch brand, generally of the first letter of the name of the proprietor, and each subdivision is distinguished from the rest by the part of the sheep's body on which this mark is placed.
By
Some Circumstances relative to Merino Sheep, 2 43
By the laws of the Mesta, each Cavaiia must be governed by an officer called Mayoral ; for each subdivision of a thou- sand sheep, five shepherds and four dogs are appointed. Some of these inferior shepherds obtain the office of Rabadan, the duty of which is to give a general su peri n tendance under the control of the Mayoral, also to prescribe and administer medicines to the sick sheep. At the time of travelling, and when the ewes are yeaning, one or two extra shepherds are allowed for each thousand sheep.
The number of Merino sheep in Spain is estimated by Burgoyne at 6,000,000 ; these of course must be attended by 30,000 shepherds, and 24,000 dogs at ordinary times, and they find occasional employment for 5 or 10,000 additional persons in the seasons of lambing and of travelling.
In their journey, each subdivision is attended by its own shepherds and dogs, and kept separate as far as may be from all others. The duty of the dogs is to chase the wolves, who are always upon the watch when the sheep are on the road, and are more wily than our foxes; they are taught also, when a sick sheep lags behind unobserved by the shep- herds, to stay with and defend it, till some one returns back in search of it. There are besides in each subdivision about six tame wethers, called Mansos ; these wear bells, and are obedient to the voices of the shepherds, who frequently give them small pieces of bread : some of the shepherds lead, the Mansos are always near them, and this disposes the flock to follow.
Every sheep is well acquainted with the situation of the Dehesa to which its subdivision belongs, and will at the end of the journey go straight to it, without the guidance of the shepherds. Here the Hock grazes all the day under the eyes of the attendants : when the evening comes on, the sheep are collected together, and they soon lie down to rest ; the shepherds and their dogs then lie down on the ground round the flock, and sleep, as they teem it, under the stars, or in huts that afford little shelter from inclement weather; and this is their custom all the year, except that each is allowed, in bis turn, an abseuce of about a month, which he spends
Q 2 with
244 Sotng Circumstances relative to Merino Sheep.
with his family ; and it is remarkable, that the families of these shepherds reside entirely in Leon.
The shepherds who came with his majesty's flock were questioned on the subject of giving salt to their sheep : they declared that this- is only done in the hottest season of the year, when the sheep are on the mountains; that in Sep- tember it is left off; and that they dare not give salt to ewes forward with lamb, being of opinion that it causes abortion. It is scarcely credible, though it appears on the best au- thority to be true, that under the operation of the laws of theMesla, which confide the eare of the sheep to the ma- nagement of their shepherds, without admitting any inter- ference on Ifa put of the proprietor, no profit of the flock come.'vto the hands of the owner, except what is derived from, the wool y the carcases of the culled sheep are consumed by the shepherds *r and it does not appear that any account is rendered by them* to their employers, of the value of the skins, the tallow, &c. t the profit derived by a proprietor ircm a flock, is estimated on an average at about one shil- ling a head, and the produce of a capital vested in a flock is said to fluctuate between live and ten- per cent*
The sheep are always low kept. It is the business of each Mayoral to increase his flock to as large a number as the land allotted to it can possibly maintain : when it has ar- rived at that pitch, all further increase is useless, as there is no sale for these sheep, unless some neighbouring flock has been reduced by mortality below its proper number : the most of the lambs arc therefore every year killed as soon as- they are yeaned, and each of those preserved is made to suck two or three ewes ; the shepherds say, that the wool of an ewe that brings up her lamb without assistance is reduced *n its value.
At shearing time the shepherds, shearers, washers, and a multitude of unnecessary attendants, are fed upon the flesh of the culled sheep m7 and it seems that the consumption oc-
• The shepherds, on discovering the drift of the questions pur to them on this head, said that in settling the wages ot the shearers and washers, at the tscuiilcos, all wajicc is made for the mutton with which, they are- fed.
casioned.
Some Circumstances relative to Merino Sheep. 245
casioned by this season of feasting is sufficient to devour the whole of the sheep that are draughted from the flock. Mutton in Spain is not a favourite food; in truth, it is not in that country prepared for the palate as it is in this. We have our lamb-fairs, our hog-fairs, our shearling- fairs, our fairs for culls , and our markets for fat sheep 5 where the mutton, having passed through these different stages of pre- paration, each under the care of men whose soil and whose skill are best suited to the part they have been taught by their interest to assign to themselves, is offered for sale; and if fat and good, it seWom fails to command a price by the pound, from five to ten per cent, dearer than that of beef. In Spain they have no such sheep-fairs calculated to subdivide the education of each animal, by making it pass through many hands, as works of art do in a manufacturing concern; and they have not any fat sheep markets that at all resemble ours. The low state of grazing in Spain ought not therefore to be wondered at, nor the poverty of the Spanish farmers ; they till a soil sufficiently productive by nature, but are rob- bed of the reward due to the occupier, by the want of an advantageous market for their produce, and the benefit of an extensive consumption ; till the manufacturing and mercan- tile parts of a community become opulent enough to pay liberal prices, the agricultural part of it cannot grow rich by selling.
s
That the sole purpose of the journeys taken annually by these sheep is to seek food in places where it can be found ; and that these migrations would not be undertaken, if either in the northern or the southern provinces a sufficiency of good pasture could be obtained during the whole year, — ap- pears a matter of certainty. That change of pasture has no effect upon their wool, is clear, from all the experiments tried in other countries, and in Spain also : for Burgoyne tells us, that there are stationary flocks, both in Leon and in Estremadura, which produce wool quite as line as that of the Trashumantcs.
The sheep lately presented to his majesty are of the Ca- vana of Paular, one of the very finest in point of pile, and esteemed also above all others for the beauty of carcase. In
Q 3 both
246 Some Circumstances relative to Merino Sheep.
both these opinions, M. Lasteyrie, a French writer on sheep, who lived many years in Spain, and paid diligent attention to the Merino sheep, entirely agrees : he also tells us, that the Cavafia of Negrete, from whence the sheep imported by his majesty in the year 1791 were selected, is not only one of the finest piles, but produces also the largest-carcased sheep of all the Merinos. Mr. Burgoyne agrees with him in asserting, that the piLes of Paular, Negrete, and Escurial, have been withheld from exportation, and retained for the royal manufactory of Gaudalaxara, ever since it was first established.
The Cavafia of Paular consists of 36,000 sheep. It origi- nally belonged to the rich Carthusian monastery of that name, near Segovia ; soon after the Prince of the peace rose= into power, he purchased the ilock from the monks, with the land belonging to it, both in Estremadura and in Leon, at a price equal to twenty French franks a head, \6s. 8d. English. All the sheep lately arrived are marked with a large M. the mark of don Manuel.
The number sent from Spain to the king was 2000, equal to two subdivisions of the original Cavafia. To make the present the more valuable, these were selected by the shep* herds from eight subdivisions, in order to choose young, well-shaped, and fine-woolled animals. This fact is evident, from the marks which are placed on eight different parts of the bodies of the sheep nowat'Kew.
The whole number embarked was 2,214; of these, 214 were presented by the Spaniards to some of his majesty's ministers, and 427 died on the journey, either at sea or on their way from Portsmouth to Kew. His majesty was gra- ciously pleased to take upon himself the whole of the loss, which reduced the royal flock to 1573; several more have since died. As the time of giving the ram in Spain is July, the ewes were full of lamb when they embarked, se- veral of them cast their lambs when the weather was bad at sea, and are rendered so weak and infirm by abortion, that it is much to be feared more will die, notwithstanding the great care taken of them by his majesty's shepherds. A few have died of the rot. This disease must have been contracted by
halnncr
• " Some Circumstances relative to Merino Sheep, 247 halting on some swampy district, in their journey from the mountains to the sea at Gijon, where they were embarked, as one sheep died rotten at Portsmouth ; there is every rea- son however to hope, that the disease will not spread, as the land on which thev are now kept has never been subject to its ravages, being of a very light and sandy texture.
It is well worthy of observation, that although the Swedes, 4jie Saxons, the Danes, the Prussians, the Au- strians, and of late the French, have, either by the fore- sight of their governments, or the patriotic exertions of in- dividuals, imported Merino sheep, no nation has hitherto ventured to assert, that they possess the complete and un- mixed race of any one Cavafia; this circumstance does not appear to have been attended to any where but in England ; though in fact, each Cavana is a separate and distinct breed of sheep, not suffered by the Spaniards to mingle with others. The difference In value of the wool of different Spanish flocks is very great ; at this time, when Spanish wool is unusually dear, the prima piles are worth more than 7-s. a pound, and yet the inferior ones scarce reach 5s.* Even the French, attentive as that nation is to all things that concern the interest of individuals, appear to have over- looked this circumstance, and to have contented themselves with making up the numbers of their importations, without paying any regard to it 5 they have not at least stated in any of their publications, that attention was paid to the securing sheep eff a prima pile, and keeping the breed of that pile pure and unmixed after they had obtained it.
Our merchants in Spanish wool range the prima piles in the following order of value, as appears by a statement in the year 1792.
Paular.
Negrete.
Muro.
Patrimonio ; and 15 more not necessary to be enumerated. M. Las.tey.ric, the French writer on sheep, ranges them not yery differently ; he .states them as follows : but both En-
* Since this was written, Spanish wools have risen to an exorbitant price. Prima Leonesa is this week rated in the Fanner's Journal at 20s. a pound, and Seville at 13s. 6d.
Q4 g]i*h
245 Some Circumstances relative to Merino Sheep.
glish and French agree that all the prima piles are nearly equal in fineness of fibre, and consequently in value to the manufacturer.
Escurial, called by us Patrimonio.
Guadalupe.
Paiilar.
Jnfantado.
Montareo.
Negrete, &c.
The Danes, he tells us, procured their sheep from the hest piles ; but there is no appearance of their having, since they obtained them, kept the flocks separate, nor are they at present so remarkable for fine wool as the Saxons, whose wool is now at least as fine as that of Spain is, upon an average of prima and second rate piles.
The Swedes were the first people who imported the Spa- nish breed. This good work was undertaken and completed by the patriotic exertions of a merchant of the name of A1-. stroemer, in the year 1723. The next who obtained an im- portation of Merino sheep were the Saxons, who are in- debted for the benefits they enjoy from the improvement of their wools to the prince Xavier, administrator of the elec- torate during the minority of the elector, and brother-in-law to the king of Spain. The prince obtained a flock of these valuable animals in 17C6, and in 1778 an addition to it of 100 rams and 200 ewes. The Danes followed his useful ex- ample, as also did both Prussia and Austria. Every one of these countries continue at this moment to profit largely by the improvement these sheep have occasioned in their agri- cultural concerns. So far from truth is the too common as- sertion, that their wool will not continue fine in any country but Spain, that in the year 1806, when the ports of Spain were closed against us, a very large quantity of fine wool, the produce of German Merino sheep, was imported into this country from Hamburgh, and used by our manufac- turers as a substitute for Spanish wool. In truth, some of this wool was so fine that it carried in the British market as high a price as the best Spanish piles were sold for, in times of peace and amity.
[To be continued.]
XLIT. On
[ 249 ] XLIT. On the Motion of Floating Bodies.
March 4, 1809.
T SIR>
JLn your Magazine of the last month, Capt. Burney made certain experiments on unloaded and loaded barges, with re- spect to their velocities in a running stream : and there was an allusion also to beams, or sticks, or timber, always moving with the heavy end foremost. These two problems may be solved in the same way, — they are the result of gravity. The heavier a barge is loaded the quicker will it move, because all water that is in motion moves down an inclined plane seeking its level ; the loaded barge that swims or floats in it will of course move down a regular inclined plane, endeavouring by the force of gravity to de- scend, and its velocity will be in proportion to its weight ; viz. to the quantity of matter moving together ; and unless resisted or opposed by a contrary force, or irregular cur- rents, it will acquire an increased velocity in a certain ratio. This is exactly a parallel case to loaded or unloaded carriages going down hill, the heavier they are, with the greater ve- locity will they press downwards ;— or, to put another case, let a cannon shot and a round piece of turned wood of the same dimensions be rolled down an inclined plane, the can-^ nou ball will roll quickest, because it contains more matter ; jn the same way it would descend quicker through the air. — A beam or stick in the water observes exactly the same laws of matter and motion, and will go down the stream with its heavier end foremost : so kirthe air, if a stick be thrown upwards, the heavier end will first reach the ground. — The savages in the South Sea Islands know this, and make cer- tain short spears or clubs, which they throw at their ene- mies, over wherever they see a crowd of them ; and these clubs fall with the heavy end downmost, and if they hit disable or kill. J am, sir, your obedient servant,
G. Orr. To Mr. Tilloch.
xuir. p?o-
C tyo ]
XL! I T . Proceedings of Learned Sock- ties.
ROYAL SOCIETY.
JVIarch 2.— The reading of Mr. Home's paper .on the in- tervertible joint discovered in the basking sh;trk, was con- cluded. Mr. Brando analysed the liquor found In this pe- culiar joint, when it proved to be almost entirely animal mucus or mucilage, without either gluten or albumen.
March 9 — 16. — Earl of Morton, vice-president, in the chair. A verv lone; memoir was read on the nature and mo- difications of coloured concentric rings, exhibited in glasses brought into contact, by Dr. Herschel. It is impossible to give any adequate idea of the numerous and diversified ex- periments performed by this indefatigable philosopher, whose narrative of them is divided into above 60 subdivisions. From these experiments it appeared that no coloured rings were produced if the glasses were of the same quality, uni- formly level, and brought perfectly into contact. Sir Isaac Newton's opinion respecting *' fits of transmission" was explained on his own principles of the known difference of refrangibilitv of coloured rays. Various other optical phe- nomena, relating to coloured rays, chromatics, and refrac- tion, were incidentally illustrated.
March Z-2. — Earl of Morton in the chair. An account of experiments on Brazilian platina, by Dr. Wollaston, was read. The very small specimen of platina from the silver mines in Brazil, which Dr. W. analysed, was given to him by the chevalier de Souza, the Portuguese minister in this country.' Vauquelin having found platina, but no palladium, in the silver mines of Guadalcanal, it was thence supposed that this metal was peculiar to the Peruvian platina. The Brazilian platina, however, has some external characters different from that of Peru ; it is brighter, flat, not rounded off at the corners, and has not that worn aspect which the Peruvian platina presents. It also contains a small quantity of gold, which was not found in the platina of Estrema- dura. But notwithstanding the smallness of the speci- men, native palladium was discernible in it by its external characters : although white, like the platina, it exhibited flat
square,
Werncrian Natural History Society. 2.51
square surfaces, which were laminous, and could be me- chanically detached from the other metals. The specimen, which Dr. W. received was too small to admit of his ascer- taining the exact proportions of native palladium, gold, and platina it contained: hut on examining the palladium apart, and dissolving it, some sensible traces of iridium were dis- covered ; and the Doctor supposes that, when sufficiently large specimens of the Braziliau platina are received, it will be found 10 contain not only palladium and gold, but also iridium and osmium, like the Peruvian platina.
WF.RNERIAN NATURAL HISTORY SOCIETY.
' At the meeting of this Society on the 11th of February, Professor Jameson read a short account of the oryctognostic characters and geognostic relations of the mineral named cryolite, from West Greenland.
Mr. P. Ncill read a description of a rare species of whale stranded near Alloa, in the Frith of Forth, in the end of October last. It was 43 feet long; had a small dorsal fin verv low down the back ; longitudinal folds in the skin of the thorax; short whalebone (fanons) in the upper jaw ; the under jaw somewhat wider, and a very little longer than the upper ; both jaws rather acuminated, the under one end- ing in a sharp point proceeding from a twisted bony ridge on the lower side. From these characters he considered it as evident that it was the Baleinoptera acuto-rostrata of La Gepede, and that that author had fallen into an error ia saying that this species never exceeds from 26 to 29 feet in length.
At the same meeting, the Secretary laid before the Society several interesting communications. 1. Copies of the affi- davits made before the justices of the peace at Kirkwall, in Orkney, by several persons who saw and examined the car- case of the great sea snake (Halsydrus Pontoppidani) cast ashore in Stronsa in October last; with remarks illustrative of the meaning of some passages in these affidavits. — 2. An account of the discovery of a living animal resembling a toad, inclosed in a bed of clay, (in a cavity suited to its size, and which retained its shape,) at the depth of fifty-seven *~ fathoms,
252 JVerncrian "hatiiral History Society.
fathoms, in the coal-formation at Govan ; communicated by Mr. Dixon of Govan-hill. — 3. An instance of remarkable intrepidity displayed by an old male and female otter, (at the river Dart, near Totness, Devonshire,) in defending their young, although the Otter is generally accounted a very timid animal; communicated by Mr. Laskey ofCrediton.
At this meeting also, Mr. Laskey (who is at present with his regiment in Scotland, and who is well known in the scientific world as an eminent conchologist,) presented to the Society a very valuable and well arranged collection of British shells, and likewise a curious mineral from New Holland.
At the meeting of this Society on the 11th of March, Dr. Yule read an interesting memoir on the natural order Gramineae, with introductory observations on monocotyle- donous plants, in which he contrasted these with the dico- tyledonous class, from the period of germination to the complete evolution of their stems. The Doctor is to con- tinue the subject in a future paper.
Capt. Laskey laid before the Society a list of Scottish Testacea, as far as they had fallen under his own observa- tion ; with remarks on the new and rare species. Of the genus Chiton he enumerated 4 species; of Lepas 3; Bala- nus 6 ; Pholas 4 ; My a 9> including 3 new species ; of Li- gula, (a lately constituted genus,) 1 species ; Solen 6 ; Tellina 15, including a new species, named by Col. Mon- tagu, T. Laskeiji ; Cardium 10; Mactra 6; Donax 3 ; Venus 23, including 9 new species ; Chama 1 ; Area 6* ; Pecten 6; Ostrea 1 ; Anomia 4 ; Mytilus 1 1 ; Pinna 1 ; Nautilus 3 ; Cypraea 1 ; Bulla 13, including 2 new species ; Voluta 8, 4 of them new ; Buccinum 8 ; Strombus 2 ; Murex 23, comprehending the rare carinatus, and 3 new ones; Tro- chus4; Turbo 32, 5 new ; Helix 17; Nerita7; Haliotis 1 ; Patella 1 1 \ Dentalium 2 ; Serpula 7 ; Vermiculum 3. This is the most ample catalogue of Scottish testacea hitherto formed; containing 126 species of multivalvc and bivalve, and 142 species of univalve shells ; in all 2G8.
At the same meeting the Secretary read a communication from George Montagu, esq., of Knowei House, giving an
account
List of Patents for New Inventions, 253
actount of a nondescript fish, five feet long, taken on the coast of Devonshire last summer. It must constitute a new genus, in the Apodal order ; and Mr. Montagu has bestowed on it the generic name of Ziphothcca, and the specific one tetradens. The communication likewise contained accurate descriptions of four rare species of English fishes ; and was accompanied with correct and elegant drawings of these, as well as of the ziphotheca. — At the same time, Mr. Mon- tagu presented the Society with copies of his Testacea Bri- tannica, and Supplement, three vols. 4to., with coloured plates, and of his Ornithological Dictionary, two vols. 8vo.
XLIV. List of Patents for New Inventions.
1. o John Dickinson, of Ludgate IJill, London, stationer, for certain improvements on his patent machinery for (Jutting and placing paper; and also certain machinery for the ma- nufacture of paper by a .new method. Jan. 19, 1809-
To George Finch, jun., of King Street, Soho, orris wea- ver, for certain methods of manufacturing various kinds of metal laces, so as to imitate gold and silver laces ; and also of manufacturing goldand silver open laces. Feb. 4.
To Thomas Potts, of Hackney, for a new process of free- ing tarred ropes from the tar, and rendering them fit for the use of the manufacturer. Feb. 4.
To Frederick Albert Winsor, of Pall Mall, esq., for cer- tain improvements upon his former patent oven stove, or apparatus for carbonising all sorts of raw fuel and combus- tibles, and reducing them into superior fuel of coke and charcgal, as well as for extracting and saving, during the same process, the oil, tar, pyroligneous vegetable acid and ammoniacal coal liquors ; and for extracting and refining all the inflammable air or gas, so as to deprive it of all disagree- able odour during combustion, and rendering the gas itself salutary for human respiration, when properly diluted with atmospheric air. Feb. 7.
To William Congrcve, of Cecil Street, Strand, esq., for his mode of construction or arrangement for any building,
so
254 List of Patents for New Inventions.
so as to afford security against (ire, with other advantages, Feb. 7.
To Archibald Thomson, of Manchester, engineer, for certain improvements on machines applicable to various kinds of spinning. Feb. 7.
To William Evcrhard Baron Doornik, of01d Lisle Street, Leicester Square, for certain improvements in the manu- facture of soap, to wash with sea-water, with hard-water, and with soft water. Feb. 7.
To John Stead, card-manufacturer, Leith Walk, Edin- burgh, for his method of manufacturing cards which are employed in the- carding and spinning of flax, tow, wool, cotton, and silk, so as to combine the quality of a fine card with the strength of a coarse one. Feb. 9.
To James Grellier, of Aldborough Hatch, in the county of Essex, esq., for a peculiar construction for the purpose of burning coke and lime, whereby the superfluous heat of the fire used in burning the coke is applied to burn the lime, and also whereby such fire may be rendered perpetual, and which he denominates " the union and perpetual kiln."- •Feb. 13.
To Stephen Hooper, of Walworth, in the county of Sur- rey, gent., for a thermometer or machine for ascertaining the heat of bakers' ovens and various other purposes. Feb. 13. To David Meade Randolph, a citizen of Virginia, in the United States of America, but at present residing near Gol- den Square, in the county of Middlesex, merchant, who, in consequence of a communication made to him from his friend and correspondent residing within the raid United States, has become possessed of a new method of manufacturing all kinds of boots, shoes, and other articles, by means of a substitute for thread made of hem;>, flax, or other yarns. Feb. 21.
To Joseph Ilett, of Stratford, in the county of Essex, calico-printer, for his method of producing fast greens on cotton and various other articles. Feb. 21.
To Leger Didot, of Two Waters, in the county of Hert- ford, for certain improvements in the construction of um- brellas and parasols. March l.
To
List of Patents for New Inventions, 255
To Richard Scantlebury, of Redruth, in the county of Cornwall, brazier, for a machine, by which he counter- balances ihe weight of any volume of water or other fluids, required to be lifted by any steam or water engine, or other machinery, either worked by animals or men, which gains a very considerable power over any machine now in use. March 1.
To Edward Steers, of the Inner Temple, esq., for a new method directed by machinery, of using the screw, by which its mechanical power or its motion is increased. March 1.
To Abraham Seward, of Lancaster, tin-plate worker, for a new improved hook, for bearing up the heads of horses in drawing carriages. March 1.
To Thomas Clatworthy, of Winsford, in the county of Somerset, sheep shears maker, and John Clatworthy, of the same place, sheep shears maker, his son, for shears on an improved construction for shearing sheep. March 1.
To Frederick Bartholomew Folch, of Oxford Street, and William Howard, of Bedford Street, Lockfields, in the county of Surrey, for a certain machine instrument or pen, calculated to promote facility in writing ; and also a certain black writing ink or composition, the durability whereof is not to be affected by time, or change of climate. March 4.
To William Proctor, of Sheffield, optician, for improved methods of raising or supplying tubes or lamps with oil, so as to remove away the shade of the vessel containing the oil, and in form and use equal to any mould or wax candle, which he denominates Proctor's spiral Argand and candle J am p. March 0.
To John [Jeathcoat, of Loughborough, in the county of Leicester, lace manufacturer, for a machine for the making and manufacturing of bobbin lace, or lace nearly resembling foreign lace. March 20.- N
To James Ilakewill, of Beaumont Street, in the parish of St. Mary-le-bone, artist, for an improvement in the con- struction of tables, chairs, and stools, for domestic, mili- tary, and naval service, and in the packing of the same. March 20.
METEORO-
£56
Meteorology*
meteorological taijle,
By Mb. Carey, of the Strand,
For March 1809.
|
Thermometer. |
1 .« |
|||||
|
Days of the Mouth. |
^2 w> P 0 00 ^ |
c § 'A |
JO ^ |
Height of tlie Barom. Inches. |
si! fen * $*> |
Weather. |
|
Feb. 25 |
40° |
47° |
42° |
30-26 |
36 |
Fair |
|
26 |
33 |
47 |
43 |
•42 |
35 |
Fak |
|
27 |
40 |
51 |
40 |
'35 |
37 |
Fair |
|
28 |
33 |
53 |
46 |
•30 |
36 |
Fair |
|
March I |
46 |
47 |
40 |
•25 |
0 |
Rain |
|
2 |
40 |
45 |
34 |
•40 |
25* |
Cloudy |
|
3 |
33 |
44 |
42 |
'33 |
37 |
Fair |
|
4 |
41 |
43 |
40 |
•16 |
20 |
Showery |
|
5 |
39 |
42 |
35 |
•18 |
7 |
Small rain |
|
6 |
33 |
39 |
33 |
•29 |
9 |
Cloudy |
|
7 |
33 |
39 |
35 |
•38 |
5 |
Cloudy |
|
8 |
35 |
43 |
39 |
•47 |
15 |
Faii- |
|
9 |
33 |
54 |
50 |
•25 |
29 |
CIoudy |
|
10 |
42 |
48 |
36 |
•24 |
30 |
Fair |
|
11 |
33 |
45 |
40 |
•19 |
33 |
Fair |
|
12 |
40 |
48 |
36 |
•09 |
57 |
Fair |
|
13 |
33 |
45 |
35 |
•20 |
51 |
Fai v |
|
14 |
41 |
45 |
36 |
•26 |
35 |
Faii- |
|
15 |
36 |
44 |
,41 |
•40 |
35 |
Fair |
|
16 |
37 |
51 |
45 |
'i7 |
41 |
Cloudy |
|
17 |
42 |
53 |
42 |
•IS |
35 |
Cloudy |
|
18 |
39 |
53 |
41 |
•'05 |
39 |
Fair |
|
19 |
40 |
51 |
44 |
29'99 |
32 , |
Cloudy |
|
20 |
41 |
49 |
41 |
30-00 |
30 |
Cloudy |
|
21 |
40 |
48 |
44 |
•14 |
15 |
Cloudy |
|
22 |
44 |
58 |
44 |
•02 |
52 |
Fair |
|
23 |
44 |
59 |
51 |
29'88 |
64 |
Fair |
|
24 |
47 |
56 |
48 |
•62 |
55 |
Fair |
|
25 |
44 |
49 |
42 |
•30 |
54 |
Fair |
|
26 |
44 |
53 |
40 |
•17 |
35 |
Cloudy |
N. B. The Barometer's height is taken at one o'clock.
t 257 ]
XLV. Observations on a late Paper ly Dr. Wm. Richard- son, respecting the basaltic District in the North of Ire- land, and on the Geological Facts thence deducible ; in Con- junction with ot tiers observable in Derbyshire and other En* glish Counties : with the Application of these Facts to the Explanation of some of the most difficult Points in the Natural History of the Globe. By Mr. John Farey.
" By making ourselves acquainted with effects, we shall be better qualified; to investigate causes ; and if those effects shai! appear to be beyo: d the powers of such natural agents as we are already acquainted with, we shall be justified in admitting the performance of operations to which we have seen nothing similar; and also in admitting the former existence of powers of far superior energy to any we have ever knowa in action." — Dr. W. Richardson.
To Mr. Tilloch, — Sir, IN ext to the delight occasioned by the discovery of any truth of important application, few things can be more pleasant to an ingenuous mind, than to observe others ar- riving at a similar conclusion, by modes sufficiently distinct to give additional evidence to the truth acquired.
I was led to these reflections, from having considered all that I had read or heard, concerning the basaltic districts of our globe, previous to the perusal of Dr. William Richardson's late able paper in ihe Philosophical Transactions, (reprinted in your two last Numbers, and which I shall take the liber- ty therefore of referring to,) as showing, that no part of the surface or crust of the whole earth was less likely to harmo- nize with the conclusions, to which I had been led, seven or eight years ago, by an attentive consideration of the geo- logical facts which Bedfordshire then presented to my mind, and which have since received ample, and I think I might say complete confirmation, in a more extended field of ob- servation.
Of the nine geological facts deduced by Dr. Richardson, as applicable to his basaltic district or area, seven of them appear exactly conformable to all my experience in other districts, including very various kinds of strata; and perhaps my not fully comprehending some expressions in his 4th and 5th facts, (page 113,) may alone have prevented a like
Vol. 33. No. 132. April 1809. R con-
2.tS 01 sen at ions on Dr. Richardson's Paper respecting
concurrence as to them. It gives me great pleasure there- fore to find, the results of my observations on the denudated districts in Sussex, Derbyshire, &c, communicated fully to numerous friends within three years past, which are shortly alluded to in your volumes (xxviii. p. 120: and xxxi. p. 37), and more fully explained under the article Denudation, and others, in Dr. Rees's New Cyclopaedia, thus fully confirmed by Dr. Richardson's able investigations, conducted, as far as I am acquainted, without any know- ledge of what I have been doing, and tending to remove all doubts as to the regular stratification of basalt.
The cutting and carrying off of the upper strata, observ- able in numerous instances in the north of Ireland, has been termed by Dr, R. (pages 114, 196,) abruptions of the strata, which word I am not inclined to adopt instead of denudations already explained, as above. The word hum- mock, introduced by Dr. R., notwithstanding the seamen have limited its use to circular knowls or points of hills, may have its meaning as a geological term extended, as Dr. R. has done, to include such as are precipitous and irregular also in their shape, and as such I shall hereafter adopt it, instead of cap, (a term much too numerous in its meanings already,) which I have hitherto used, in pointing out to my friends in Derbyshire, the numerous hummocks on their de- nudated hills ; where these detached pieces of strata, being mostly accessible on all sides, have furnished the strongest evidence both to myself and others on the spot, (as similar ones have done in Ireland to Dr. Richardson,) that the in- tervening parts of the same stratum, once continuous, have .been torn off from our globe.
Before I had ever seen a hummock or heard of a denu- dated district, from observing the universality of fissures or faults in Bedfordshire, having their sides always po- lished or worn, pursuing rectilinear courses, quite incon- sistent with the crater-like action of any force hitherto sup- posed to have acted from below, I was irresistibly led to the consideration of forces acting from above, as Dr. R. has also been, by the evident excavation of valleys and leaving of hummocks in his basaltic area.
The
the Basaltic District in the North of Ireland, 259
The worn state of those faults, which make at present no alteration in the level of the strata on each side of them, in common with those which, as doing otherwise, might admit of explanation bv the mere slip or subsidence of one side, obtruded the conclusion, that successive and general heav- ings of the surface were necessary, to account for this phae- nomenon, so universally overlooked by geologists in their writings; and Gravity, that most powerful of known agents, which, now that no satellitic body remains nearer to the earth than 240,000 miles, daily heaves up a mass or column of sea water, perhaps 1000 miles diameter and ten feet high ! appeared to me as the probable cause, through the medium of a large and perhaps very dense body, that might have re- volved round this globe, at that awful but important period, when f* God said, Let the waters be gathered together, and let the dry land appear."
These ideas of accounting for the universality and worn state of faults, I had very shortly after the opportunity of explaining to the worthy President of the Royal Society, when on a visit to that inestimable character the late Duke of Bedford, in a day's ride over the district which had fur- nished the materials for these speculations, and while the progress of His Grace's extensive works then carrying on, admitted of verifying most of the facts. The sudden loss of my former patron, having occasioned the turning of my attention more particularly to the acquirement of geological knowledge, I have since had the happiness of finding these first ideas of mine, when applied to a satellite moving near enough and with attraction sufficient, to reverse the direc~ tion of gravity for the instant of its passage, over any given tract on the earth's surface, as fully adequate to account for the numerous, and to me new and astonishing facts, which my researches in Sussex, Derbyshire, Staffordshire, &c, have since furnished : the details of these I intend to pub- lish, as soon as my observations on Derbyshire and the sur- rounding borders of other counties shall be completed, and my professional avocations will allow. In the mean time, I have been anxious, to suggest the above effects and their causes, for the consideration of those, who, like Mr. IVm.
R 2 Smith,
L2Go Observations on Dr. Richardson's Taper respecting
Smith, Dr. Richardson, M. Andre, &c, may engage in extended and minute inquiries, as to <c the actual surface of the earth," (p 1 70 of the present volume,) without which direction to their inquiries, the mention or" geology must continue to be received with a smile, as M. Cuvier and his very able associates justly remark.
In order to show that hummocks or isolated caps of strata are not confined to basalt, or any other stratum in particu- lar, but are of common occurrence irr denudated districts, I beg to present the following list of a few which I have ob- served, and noted most of them, in the part of my geological map of Derbyshire, a copy of which has been now some time in possession of my worthy patron in these pursuits, the President of the Royal Society, referring for some furtherpar- ticulars, to my Section plate II. of your thirty-first volume.
Hummocks with Coal measures on their tops. Hill North of Ounston, near Dronfield, Shutlings Low, near Macclesfield, Cheshire.
Hummocks with First or Millstone Grit on them.
Stanton Moor, near Winster,
Hartle Moor, ditto,
Comb's Moss, near Buxton,
Lose Hill, N.E. of Hope, - Grindlow Rime, N. of Edale,
Sheenhill, near Longnor, Staffordshire,
Revedge, near Warslow, ditto. Sometimes these appear, as single or romantic isolated Rock*. on the millstone grit districts, as
Alport Tor-stone, in Wirksworth,
Thoma's Chair, on Stanton Moor, near Winster,
Endle Stone, - ditto, - ditto,
Rowter Rocks, at Birchover, - ditto,
Mock-beggar Hall, on Hartlemoor, ditto. Hummock? or Caps of part of the First Limestone,
Gree Tor, S. of Winster,
Bank's Pasture Rocks, ditto,
Dungeon Rocks, near Wen sley,
St. Peter's Rocks, in Cresbrook vale, nearWardlow.
Hummocks
the Basaltic District in the North of Ireland. 261 Hummocks of the Second Limestone,
Hobthurst Houses, in Wey-dale, near Little Longstone, Hill N. of Miller's dale, near Tidswell, Wormhill, near ditto, Tunstead Hill, near Wormhill, Bole-end Hill, ditto.
Hummocks of the Third Limestone, Aldwark, near Brassington, Hill N. E. of Green Fairfield, near Buxton, Buxton Town.
Hummocks of the Third Toadstone, Staden Hill, near Buxton, Knot Low, near Wormhill, Cawton Low, near Chelmerton, Harborough Rocks, near Brassington.
The hummocks of the Fourth Limestone differ from many of the others above, in our not being able to see these iso- lated masses, resting on any under stratum, since none of the very deep valleys which intersect it, are excavated deep enough, to reach any under measures. The numerous iso- lated conical and peaky hills in Hartington, and other pa- rishes on the W^. side of the Limestone district, are all a sort of massive hummoeks, too numerous here to be named.
In Dove-dale, in this stratum very extraordinary small hummocks occur, or rather perhaps, in the rude and very wide barren veins by which the vale was intersected : — these are called Tissington Spires, the Sugar Loaves, &c. — Rey- nard's Tor, Hoc-cliff, Pike Tor, 8cc, in Brassington, are also among the interesting hummocks of this stratum.
The above list, contains none of the many curious "and conspicuous hilis of this district, which are crowned by pro- jecting or suddenly elevated points or edges of strata, still connected with the mass, but only such whose strata or up- per beds, are entirely isolated by a surrounding denudation.
Small hummocks of Gravel on the heights of this denu- dated tract, consisting of sanu\ mixed with quartz and other very hard and highly rounded pebbles, (not of the rocks of any known part of the glob*, as has been said,) at some
R 3 miles
262 Observations on Dr. Richardsnji*s Paper respecting
miles distance from any other gravel, are perhaps among its most curious phenomena : — these I have observed at Thorney Ley, W. of Chapel le Frith, E, of Kilburn, near Horsley, S. of Strelly, Notts,
On Sheepston Hill, W» of Anncsley, Notts. After revolving the circumstances of excavated valleys m my mind, as I have travelled in these pursuits, for weeks and months together, and observed these valleys wonder- fully distributed over the whole surface of large districts, effecting a descending outlet or drainage to every part there- of, as perfectly, though with none of the constant regula- rity, in which the veins are distributed over an animal, for returning its blood from every part to the heart : I have been lost in conjecturing any application of mechanical or known principles, that could have directed the almost irre- sistible forces which effected tins important, and as it were, finishing operation upon the matters of our globe, but must refer the same to Omnipotent Power itself, acting perhaps in this instance, without the intervention of the agents, whose operations in nature the light of science enables us in so many instances to trace.
Dr. Richardson's expressions in his 3d fact, (p. 112) and mine above, might perhaps be construed as asserting, that the form of the surface of a denudated tract or excavated valley, is uninfluenced by the arrangement or alternations of its strata: such, however, is seldom strictly the case; for though to a cursory or inexperienced observer, the contour of most valleys and hills seems regular, except where there are facades or cliffs, yet a more attentive examination of the outline of such denudated or abraded surfaces, will dis- cover the edge or top of every stratum which is materially harder than that above it, as grit- stone under clay, &c, by means of a slight protuberance, or tablet as some have called it, visibly projecting the surface, but so slightly as in most instances to have escaped the notice1 of persons on the spot, and yet I have scarcely ever failed of late, in being able to discover the position of the strata in a denudated tract, com- posed of several strata, by this means alone, and frequently
at
the Basaltic District in the North of Ireland, 263
at some distance, and can often distinctly trace the bases to three or four different strata at the same time, as I ride alongj sometimes for miles together, before any pits or quarries are found, open,, by which to identify the substances of which they severally consist.
I mention the above, both as a circumstance of great practical importance in mineralogical surveying, and also as tending to prove, that the strata had acquired their present comparative hardness, before the denudation and excava- tions spoken of, took effect : the faults likewise have hap- pened since the consolidation of the strata, as their ground edges in numerous instances prove, and the disarrangement they occasioned in the strata must likewise have occurred^ prior to the final denudations and excavations of the surface, since very few of the numerous faults which raise the mea- sures on one side or depress those on the other, are visible by any inequalities on the surface, except that a very atten- tive and experienced eye may often discover their situation, by means, of the interruptions they give to the faint tablets of strata, above described : by which, I have sometimes greatly surprised practical miners in tracing out the principal faults of their district : a circumstance often of the utmost importance in practical mining.
I cannot conclude this letter, without heartily congratu- lating Dr. Richardson on the very great progress which he has made in these inquiries, and expressing a hope, that he will still persevere; endeavouring also to bring fresh labourers into the field, for the purpose of giving us a general and connected idea, of the order and position of all the principal strata of the interesting island wherein he resides. Maps also, showing by different colours, the surface occupied by each particular stratum, and vertical sections in particular directions similarly coloured, are much wanted, and will, I hope^ ere long, be undertaken.
I am, sir, your obedient servant,
JOHN FaRKY, Mii}eralog?c<lSurveycr.
12, Upper Crown Street, Westminster, April 5, 1809.
R4 XLVI. Ana-
t 264 ]
XLVI. Analysis of the Mecanique Celeste ofM. La P^ace, Member of the French Institute, &c. By M. Biot *.
JNewton, by publishing his Principia and the immortal discovery of universal gravity, gave a new direction to the physical and mathematical sciences. He was th« first who demonstrated that, in order to discover truth in the study of nature, it was not necessary to imagine precarious causes ki order to deduce: from them hypothetical results, but to ascend by a course of well -directed inductions from the phenomena observed to the laws which produce them ; and in this point of view we may regard this great man as having prepared the way for all the discoveries of his successors, Newton presented under the synthetical form, results which might probably have been attained by a different route; and herein he perhaps attached himself to his avowed predilection for the method of the ancients ; and probably, also, he gave way to a desire of concealing the course which he had pur- sued. Modern geometricians, without entirely abandoning constructions, which are always satisfactory to the mind, have, felt that the assistance of analysis was necessary for giving to the principle of universal gravity all the develop- ments of which it is susceptible; and it is to this happy- idea, and to the progress of the integral calculus, that the theory of the system of the world owes the perfection which h£s now been attained ; a perfection so great, that there does not exist any astronomical phsenomenon, the causes and laws of which cannot be assigned. But these valuable dis- coveries, the results of the labours of a small number of men, were too isolated from each other, and the chain by which they were united too difficult to unravel, in order to bring '.hem uithin the reach of the greater number. It be- came important therefore to collect them in a work of the , same nature, but in a form different and more complete than that of Newton. This task required an equally inti- mate acquaintance with astronomy and with analysis, and particularly that philosophical mind which discusses phae-
« Translated from the French,
nomena
Analysis of the Mccanique Celeste of M. La Place, 265
nomena with care, compares them with each other, and, removing the illusions of imagination and of the senses, penetrates to the true laws of nature. In these respects the task fitted M. La Place exactly, who from the outset of his career directed his researches towards the celestial phe- nomena, and who has since taken an active part in the progress of this science, by publishing, upon every point connected with the system of the world, a crowd of Me- moirs filled with important discoveries. It is principally from these memoirs that M. La Place has derived the ma- terials of this great work : and if he has connected them with each other by an admirable coincidence, it has arisen from all of them having become peculiar to himself, either because he had been the first to discover them, or from the new form which he has given to them.
Astronomy, considered under the most general point of view, is a great problem in mechanics, the elements of which are furnished by observations. This problem is very susceptible of being submitted to calculation ; because the immense distances which separate the celestial bodies, at- tenuating the secondary causes, which might act upon them, in order to bring into view only the principal forces which animate them, give to their movements a rigour and preci- sion truly mathematical. To develop the relations which exist between the motions and forces which produce them; to deduce from thence the nature of the force which ought to animate celestial bodies, in order that their movements may be such as are presented to us by observation ; thus to raise ourselves to the principle of universal gravity, and to re-de- scend from this principle to the explanation of all the ce- lestial phenomena, even to their minutest details, such is the object of the Mccanique Celeste, and such has been the ob- ject of the labours of M. La Place.
BOOK FIRST.
After having first detailed the principles of the compo- sition and decomposition of forces, the author establishes the conditions of equilibrium for any point wanted, by any number of forces acting in any given directions; conditions
which
266 Analysis of the Mccaniqae Celeste of M. La Place.
which reduce it to this, namely, The sum of the products of each force by the element of its direction is null. He teaches ns to determine, when the point is not free, the pressure ex- orcised by it upon the surface or upon the curve to which it is subjected. Considering afterwards the point in the state of motion, he seeks the relation which exists between the forces that animate it and the velocities which should re- sult from it; and byavery delicate analysis, and considera- tions drawn from experience, he demonstrates that, in na- ture, this relation of the force to the velocity is the propor- tionality. After having developed the immediate conse- quences of this law, the author gives the equation of the movement of a point animated by any given forces, and de- termines the pressures exercised by this point upon the sur- face or upon the curve to which it may be subjected. He afterwards makes the application of these principles to the motion of bodies animated by gravity in a resisting medium, and to that of a point gravitating upon a spherical surface. The isochronism of the very small oscillations of this move- able point leads to the problem of tautochrones which the au- thor resolves, in the case where the resistance of the medium is proportional to the two first powers of the velocity. He is afterwards occupied with the conditions of the equilibrium of any system of bodies considered as points : he writes down for each of them the equation of the equilibrium ; and uniting these results, he extracts from it the principle of the virtual velocities, which is thus demonstrated in a direct and general manner. After having shown how we deduce from this the reciprocal actions of the bodies of the system, and the pressures which they exercise upon external obstacles, he makes the application of them to the case in which all the points of the system are invariably united together; and this leads him to treat of the centre of gravity. The author afterwards considers the conditions of the equilibrium of fluids : the property which characterizes them being a per- fect mobility, it is necessary, in order that a fluid mass be 10 equilibrium, that each of the molecules composing it be in equilibrium in virtue of the forces which animate it. The author, setting out from this principle, determines the rela- tion
Analysis of the Mecarnquc Celeste of M. La Place. 2&T
tion which should exist between the forces which solicit the system in order to fulfil this condition, and he makes appli- cation of it lo the equilibrium of a homogeneous fluid mass covering a fixed solid nucleus, and of a given figure. He afterwards gives the general equation of the movement of any system of bodies, which he deduces from that of equili- brium ; and he draws from it the principles of the preser- vation of living forces, of areas, of the motion of the centre of gravity, and of the least action. He fixes the circum- stances in which these principles take effect, and gives fhe method of estimating the alteration which that of living forces undergoes in the sudden changes of ihe motion of the system. In treating of the. principle of the areas, he shows that in the motion ot a system of bodies animated solely by their mutual attraction, <md by forces directed towards the origin of the coordinates, there exists a plane passing by this origin, and which enjoys the following' remarkable proper- ties : 1st, The sum of the areas traced upon this plane by the projections of the vector radii of the bodies, and multi- plied respectively by their masses, is here the greatest pos- sible. 2dIy,This same sum is null upon all the planes which arc perpendicular to it ; the principles of its living forces and of the areas, still taking place with respect to the centre of gravity, even supposing it to have an uniform and recti- linear movement. Hence it results that we may determine a plane passing by this moveable origin, and upon which the sum of the areas described by the projections of the vector radii of bodies, and multiplied respectively by their masses, is the greatest possible. The author shows that this plane is parallel to that which passes by the fixed origin, and sa- tisfies the same conditions. Hence he infers, that the plane passing by the centre of gravity, and determined according to the preceding conditions, always remains parallel to itself in the movement of the system; a singular ad vantage, and which renders it of the greatest utility. It is another remarkable circumstance, that every plane parallel to the. above, and passing by any one of the bodies of the system, will enjoy analogous properties. After having obtained these valuable results, the author examines the laws of movement which . r could
268 Analysis of the Mecanique Celeste ofM. La Place.
could take place in every possible mathematical relation between the velocity and force. He shows that there exist in this general case, principles analogous to those of the conservation of the lining forces, of the areas, of the move- ment of the ecntre of gravity, and of the least action in na- ture. Ke draws from these* results the conditions which es- sentially distinguish the state of motion from that of equili- brium.— These very remarkable connections are entirely new. The laws of the motions of transposition and rotation of solid bodies are afterwards developed with the greatest extent. The author here demonstrates the properties of the principal axes, and their use in the determination of the momenta inertia? : he searches for the place of the points which re- main immoveable during the instantaneous movement of the body ; and he is led in a very simple manner to observe, that these points are situated upon a straight line, whence he infers, that every movement of rotation, of whatever kind it may be, is nothing else than a movement of rotation around a straight hue fixed during an instant, and variable from one instant to another, a property which has procured it the name of instantaneous axis of rotation. The author applies these principle's to the case where the movement of the body is owing to a primitive impulsion which does not pass by its centre of gravity : he shows how we may deter- mine the discance of the centre of gravity from this impul- sion, when tji J circumstance* of the movement of the body arc known, and he gives an example of it drawn from the movement of the carJi.
He after urrds considers the oscillations of a body which turns very nearly round one of its principal axes. He de- monstrates that this movement is stable around the two principal axes, the momenta inertice of which are the greatest and the smallest, and that it is' not around the third princi- pal axis; so that this last motion may be sensibly affected by the slightest cause. He afterwards integrates the equa- tions which determine the movement of rotation in the hy- pothesis of the very small oscillations. Finally, he examine? ihe movement of a body subjected to turn around a fixed axis) and supposing this body animated by gravity alone,
he
Analysis of the Mecanique Celeste of M, La Place. 26"9
he determines the length of the simple pendulum which would make its oscillations in the same time. The author afterwards takes up the motion of fluids : he establishes the conditions necessary, in order that this movement may take place, and that the continuity of the fluid at the same time may be always satisfied : he discusses certain cases in which these equations are integrable, such as the case where the density being any given function of the pressure, the sum of the velocities parallel to the three rectangular axes, multiplied each by the element of their direction, forms an exact vari- ation; a condition which will he fulfilled at every instant if it be in one alone. This case takes place when the motions of the fluid are very small ; and the author draws from it the equations which involve the theory of the very small undu- lations of homogeneous fluids. Considering afterwards a homogeneous fluid mass, endowed with a motion of rota- tion uniform around one of the rectangular axes, he shows that this hypothesis verifies the equations of the movement and of the continuity of fluids ; whence he concludes that a similar movement is possible. This case is one of those in which the sum of the velocities multiplied respectively by the elements of their direction is not an exact variation m7 whence it follows, that motion may take place without this condition being fulfilled.
The author afterwards determines the oscillations of a fluid homogeneous mass, covering a spheroid endowed with an uniform movement of rotation around one of the rectangular axes, supposing this fluid mass to be deranged from the state of equilibrium, by the action of very minute forces r applying these considerations to the sea, and regarding its depth as very small, relatively to the terrestrial radius, he thence deduces the conditions of its motion ; and comparing them with those of its equilibrium, he shows ihat^ach point - of the spheroid covered by the sea is more pressed in the state of motion than in that of equilibrium, from the weight of the smalicolumn of water comprehended between the sur- face of the sea and the surface of level ; this excess of pres- sure becoming negative in the points where the surface 19 lowered below the level. It results also from the same ana- lysis,
270 Description of a new Fence
lysis, that supposing the initial velocities and their first dif- ferences, divided by the element of the time, had been the same with respect to the molecules situated upon the same terrestrial radius, these molecules will remain upon the same radius during the oscillations of the fluid. The author treats the motions of the atmosphere in the same manner, looking only to the regular causes which agitate it. He first con- siders it in the state of equilibrium ; and comparing the con- ditions resulting from this supposition with those which the equilibrium of the seas necessitates, from this he infers, that, in the state of equilibrium, the stratum of air contiguous to the sea is every where of equal density ; and that the atmospheric strata of equal density are every where equally raised above the level of the sea, with very small exceptions, which, in the exact calculation of the height of mountains by- barometrical observations, ought nor to be neglected.
The author afterwards examines if it is possible that the molecules of air situated originally upon' the same terrestrial radius, still remain upon this radius during the motion which takes place in the oscillations of the sea. He shows that this supposition satisfies the conditions of the motion, and of ihe continuity of the atmospheric fluid : in this case the oscillations of the various strata of level are the same. These variations of the atmosphere produce analogous oscillations m barometrical altitudes. The author determines them, and shows that they are similar to all elevations above the level of the sea, and proportional to the altitudes of the mercury in the barometer, in the state of equilibrium, at these eleva- tions.
[To be continued.]
XLVII. Description of a new Fence made of tori elastic Wire, which lecomes invisible at a comparatively short Distance, calculated for Pleasure- Grounds. By Henry Howell, Esq. To Mr. Tilloch, — Sir, Oiiould you deem the following description, a#d the ac- companying plate of a fence for pleasure- groufflfds, upon a
new
made of tort elastic Wire. 27 t
new principle, at all deserving a place in the Philosophical Magazine, you will oblige me by giving it that distinc- tion.
The basis of the invisible fence is elastic iron wire, ma- nufactured and applied on principles discovered by Mr. James Pilton, King's Road, Chelsea, Middlesex.
This infrangible material for the main wires is drawn out to the thickness of a common quill, of which continuous strings are inserted horizontally through upright iron stan- chions : the interval between the strings is about nine inches ; between the stanchions, about seven feet. The ho- rizontal wires, in a state of tension, are fastened to two main stanchions at the extremity of the fence, passing at freedom through holes drilled in the intermediate stanchions. The tension of every horizontal wire is preserved by the superior stability of the extreme stanchions ; on the construction of which, and the mechanism of the base work, the resistance of the whole, as a barrier against heavy cattle, depends. When the extent of the fence is great, the main stanchions are re- lieved at expedient distances by other principal stanchions: an improved mode of joining horizontal wires qualifies every part of the length to bear the highest degree of tension.
The invisible fence, in this simple form, of the height of three feet six inches, has, in the Royal Pleasure Grounds at .Frogmore, and in various parks of the nobility and gentry, been found adequate to exclude the largest and strongest kinds of grazing stock. Increased in height two feet, the fence becomes applicable to deer parks. Deer have never been known to injure it, or attempt to leap it; from its transparent appearance they probably regard it as a snare.
When it is intended further to keep lambs out of planta- tions, perpendicular wires, comparatively slight, are inter- woven upon the lower horizontal wires ; and to protect flowers and exotics from hares and rabbits, it is only neces- sary to narrow the interstices by minute additions to the upright wires.
On substances so small, presenting a round surface, nei- ther rain nor snow can lodge; independent of which, bv a
coating
272 Inscription of anew Fence, &c.
coating of paint they are preserved from the effects of the weather.
The strength attained, by the principles on which the ma- terials are manufactured and the erection of the fence is conducted, cannot be justly conceived but by a person who has witnessed the effect of a considerable force impressed, or weight lodged on a single wire of a fence erected. The tempered elasticity of the tort string allows it to bend, and on the removal of the pressing force, the wire vigorously recoils, vibrating till it reassumes a perfectly straight line 5 which shows that a violent shock cannot warp it.
With regard to the effect of these transparent boundaries in opening a view, a pleasure-ground intersected or sur- rounded with them must be surveyed before an estimate can be formed of the small distance at which they vanish from the eye and leave the prospect free; — this distance may be fixed by experience at seventy yards.
To advert a moment to the utility of the new principle, (by which the invisible fence can be rendered strong and du- rable in any degree demanded,) — from the theory of Mr. Repton, previous to their discovery, it may be collected, that a secure substitute for the heavy and unsightly fences, often found indispensable near the basement windows of a man- sion, was a desideratum ; and his practice, since the satisfac- tory trials made in many counties of the new transparent fence, sanctions its adoption. In his large and elegant pub- lication on Landscape Gardening, that able improver of rural scenery states many objections to the Ha Ha; and regrets the necessity for interposing substantial boundaries to a grazed circle near the house, which counteracts a designer in pursuing the incontestably judicious maxim, that the fences in a park cannot be too few. Under a skilful direc- tor, the new principle, in the multifold applications of which it is capable, is a powerful instrument in creating artificial beauties round a country residence, or in opening a prospect to adorned nature, where a pleasing fore- ground and en- chanting distance have been hitherto shut out. (See the Plate.)
The
On the Affinity existing between Oxides, &c. 273
The inventor of these transparent fences has been en- gaged by Mr. Repton to erect them on several estates di- stinguished for extent and beauty.
I have the honour to be, sir,
your most obedient humble servant,
16, Lower George Street, HEN RY HOWELL.
Sloane Square.
XLVIII. On the Affinity existing between Oxides of Carbon and Iron. By David Mushet, Esq.*
[Continued from p. 241.]
Experiment X.
V^hakcoal from Norway Pine,
Composed of oxide of carbon 98* 1 79 Ashes - - 1 821
100 parts,
15 grains of this charcoal were mixed with 200 grains of oxide of iron. The fusion of this compound afforded a me- tallic button that weighed 40 grains, equal to 20 per cent.
75 grains of Norway pine, requisite to 15 grains of its charcoal and 200 grains of oxide of iron, produced a metal- lic button weighing - - 62 grains. Revived with charcoal as above - 40
Increase (equal to 1 1 per cent.) 22
Experiment XI. Charcoal prepared from Lignum Vitae,
Composed of oxide of carbon Q8* 1 38
Ashes - - 1*862
100 parts.
15 grains of this charcoal were mixed with 200 of oxide
* The Reader is requested to correct the following errors in Mr. Mushet's last communication in the present volume : — Page 160, line 2, for 41^. read 141 grains of iron; page 160, line 1 1, read one part of Lynn sand ; page 161, line 9, for mid of charcoal read aid of, Sec. — AUo in page 121, for toiled read failed up and put into the retort.
Vol. 33. No. 132. April 1S0Q. $ of
274 On the djjinity existing between
of iron. The metallic result from the fusion of this mixture was 38 grains.
55 grains of raspings (equal to 15 grains of the charcoal and 200 of the oxide) gave
A metallic button weighing 58*73 grains. Revived with charcoal - 38*
Increase (equal to 10*371 pet cent.) 20|
Experiment XII. Charcoal prepared from Chestnut,
Composed of oxide of carbon 98*20
Ashes - - 1*80
100 parts.
15 grains of this charcoal and 200 of oxide of iron pro- duced by fusion a metallic button that weighed 40 grains, (equal to 20 per cent.) from the oxide of iron.
83 grains of chestnut wood were found, by a calculation of the loss it sustained in charring, to be equal to 15 grains of charcoal : that quantity, in the state of raspings, was mixed with 200 grains of oxide of iron, and produced by fusion a metallic button (equal to 29 percent, from the oxide)
Weighing 58 grains.
Revived as above with charcoal 40
Increase (equal to 9 per cent.) 18
Experiment XIII. Charcoal prepared from Laburnum,
Composed of oxide of carbon 95*20 Ashes - - 4*80
100 parts.
15 graius of this charcoal and 200 of oxide of iron yield- ed a metallic button of iron weighing 41 grains (equal to 20 1 percent.).
73 grains of laburnum (being found equal to 15 grains of coal) and 200 grains of oxide of iron, mixed intimately together, produced a metallic button (equal, to 251 per cent.)
Weighing
Oxides of Carton and Iron* * 275
Weighing 52 grains.
Revived with charcoal - 41
Increase (equal to b\ per cent.) 11
Experiment XIV. Charcoal prepared from Scotch Oak,
Composed of oxide of carbort 98*133
Ashes - - 1-865
/ 100 parts i
15 grains of this charcoal and 200 of oxide of iron were intimately mixed, and fused together. A button of iron was obtained that weighed (equal to 27 per cent.) 54 grains.
65 grains of oak being requisite to form the above, 15 grains of this charcoal were mixed with 200 grains of oxide of iron. The fusion of this mixture was productive of a button of iron that was found to weigh (equal to 31| per cent.) - 63 grains.
Revived with 15 grains of charcoal 54
Increase (equal to 4| per cent.) 9
Experiment XV. Charcoal prepared from the White Wood of the same Oak> Composed of oxide of carbon 97*325 Ashe9 - - 2*675
100 parts.
15 grains of this charcoal and 200 grains of oxide of iron yielded a metallic button that weighed 49 grains (equal to 244 per cent.)*
96 grains of white wood, found by calculation from ex- periment to be equal to 15 grains of charcoal, were mixed with 200 grains of oxide of iron, and the compound reduced by fusion. The result was a metallic button that weighed (equal to 341 per cent.) 69 grains.
Revived with charcoal * 49
Increase (equal to 10 per cent.) 20
S 2 'Experiment
276* On the JJfinity existing let ween
i
Experiment XVI. Charcoal prepared from Ash,
Composed of oxide of carbon 95*727 Ashes * - 4-273
100 parts.
15 grains of this charcoal and 200 grains of oxide of iron were fused together, from which was obtained a me- tallic button that weighed 54 grains, or 27 per cent., from the oxide of iron.
80 grains of ash wood was found equivalent to the forma- tion of 15 grains of this charcoal. To these were added 200 grains of oxide of iron. The fusion of the compound pro- duced a metallic button of iron weighing (equal to 32*75 per cent, from the oxide) - » 65*5 grains. Revived with the charcoal 54
Increase (equal to 5| per cent.) 11*5
Experiment XVII. Charcoal prepared from Bark of the same Ash, Composed of oxide of carbon 93*55
Ashes - - 6*45
100 parts.
15 grains of this charcoal were mixed with 200 grains of oxide of iron and fused together, and there resulted a metallic button of iron that weighed 41 grains (equal to 20 \ per cent.).
78 grains of this bark were found requisite to form the above portion of 15 grains of charcoal. That quantity was therefore thoroughly mixed with 200 grains of oxide of iron. A metallic result was obtained by the fusion of the com- pound, ami the resulting button weighed (equal to 33£ per cent.) - 67 grains.
Revived with charcoal as above 41
Increase (equal to 13 per cent.) 26
Experiment
Oxides of Carbon and Iron, 27 1
Experiment XVIII. Charcoal prepared from Birch,
Composed of oxide of carbon 89*681 Ashes - 10-309
100 parts.
15 grains of this charcoal and 200 grains of oxide of iron yielded by fusion a metallic button of cast iron that weighed 62 grains (equal to 31 per cent, from oxide).
90 grains of birch-wood, being found equivalent to the above 15 grains of charcoal, were mixed, in the state of rasp- ings, with 200 grains of oxide of iron. The result on fusion was a button of iron
Weighing (equal to 33 per cent.) 66 grains. Revived by means of the charcoal 62
Increase (equal to 2 per cent.) 4
Experiment XIX. Charcoal prepared from Sycamore,
Composed of oxide of carbon 94*593 Ashes - - 5*407
100 parts ,
15 grains of this charcoal being mixed with 200 grains of oxide of iron and fused, a metallic result was obtained that weighed 50 grains (equal to 25 per cent, from oxide of iron) .
79 grains of sycamore raspings (equal to 15 grains of char- coal) and 200 grains of oxide of iron yielded by fusion a me- tallic button that weighed (equal to31ipercent,)63 grains. Revived by means of the charcoal 50
Increase (equal to 6\ per cent.) 13
Experiment XX. Charcoal prepared from Lime-tree,
Composed of oxide of carbon 96*321 Ashes , - 3-679
100 parts. S3 15 grains
278 On the Affinity existing between
15 grains of the above charcoal and 200 of oxide of iron gave a metallic button weighing 51 grains (equal to 25f per cent, from oxide of iron).
83| grains of raspings, as requisite to form the above quantity of charcoal, and 200 grains of oxide of iron, being mixed and perfectly reduced, afforded a button of iron that weighed (equal to 34{ per cent.) - 69 grains.
Revived by means of charcoal 5 1
Increase (equal to 9 per cent.) 1 8
Experiment XXI. Charcoal prepared from Bragnut of the specific gravity
pf 1-1009,
Composed of oxide of carbon 96-250 Ashes * 3*750
100 parts,
15 grains of this charcoal were mixed with 200 grains of pxide of iron, and the result by fusion was a metallic button weighing 36 grains (equal to 18 per cent.).
45 grains of bragnut were found equivalent to form 15 grains of charcoal. These in a state of raspings, and 200 grains of oxide of iron, were mixed together and fused; the result was a metallic button of iron weighing (equal to 2 J per cent.) 42 grains.
Revived by means of charcoal 36
Increase (equal to 3 per cent.) 6
From the result of these experiments, it will appear at one glance, that the extent and purity of the carbonaceous matter in charcoals do not at all depend upon the absolute quantity of combustible matter they contain respectively.
The largest portion of revived iron is obtained with char- coal of birch, the quantity of combustible matter in which (by Experiment XVIII.) is 89'681. Iron revived 62 grains. Combustible matter in oak 98*135 - 54
In ash 95*725 - 54 ,
In, walnut 96*048 - 30
This
Oxides of Carbon and Iron, 279
This contrast is quite sufficient to show that the different carbonating powers of charcoal of wood depend upon a principle different from any that has been developed in the foregoing experiments.
From the same experiments, however, we are warranted to conclude, that the carbonating powers of the matter of carbon contained in different woods in their natural state, are greater than when the same is reduced to charcoal by distil- lation or any other mode of operation. This curious fact, the reverse from what might have been expected, may be ac- counted for in three different ways.
1st, From the decomposition of the oleaginous or resi- nous juices of the wood by the oxide of iron ; part of the carbonaceous matter of which, being set free, may either unite itself to the iron, or unite with the oxygen of the ox- ide, and by this means leave greater scope to the carbonating powers of the concrete carbon.
2dly, From a large surface being exposed by wood in the state of fine sawdust to the same bulk and weight of oxide.
3dly, And what seems to be the most permanent cause, this fact may arise from a certain degree of oxidation being necessary in the carbon, which facilitates its union with the oxygen of the oxide; and as the degree of oxidation in raw wood is greater than in charcoal, so in proportion to this degree of oxidation we find the affinity more speedily and more extensively exerted.
The following Table will prove a convenient summary and contrast of the foregoing experiments.
S 4 ' Tatte
280 On the Affinity existing letween Oxides of Carlon and Iron*
|
Increase of Iron with Raw, beyond that of Coaled Wood. |
G 0 0 |
|||||||||
|
\ |
in » c |
-'>-« CN ~* — -, _ c» CN —• ~< C* 01 r- < — |
||||||||
|
4 i •s- «*3 |
i-s ... a> > U Oi > *-. C > « |
a B O u <u & 3 c 5 |
[ |
|||||||
|
e S Si |
Weights of Wooding requisite to form 15 grs. of Charcoal. |
-"♦ Mm hN ' «i* |
3 |
|||||||
|
Quantities of Iron revived with 15 Grs. of Charcoal. |
3 ■ 0 u H & |
"to Hot «4h -|3» -|<* CO O ^ C - <»PC— •00OO>OOt^-"^b».O'-'»C»^0 -HCHOlCN^QqO<CT-HOq«C<CNC^G^C^W^W'- |
||||||||
|
1 J ! |
{a .2 |
©O^OWOOW©O00O'-^OtJi-O1O'-(C |
||||||||
|
100 Parts of Charcoai of each Wood com- posed of |
O < |
OCOQOOCDCOQOrHCOCOCDCDOOCD?OCil^eO^<Ob |
> 5 J | 1 1 > •J |
|||||||
|
"9-2 |
QOOG-'JOOO'*iO'OOooOO'r'»ot^Q— •«— C OC)C5C>0iO0)0i0iOC5OC»C>Q0)0SQ0 CJCiC |
|||||||||
|
as P u o fl § |
0m CC |
£ |
Holly Beech |
American Maple . . Spanish Mahogany Sallow ..........; American Black Beech Norway Pine Chestnut |
Laburnum Scotch Oak White Wood of Do. Ash Bark of Ash tiirch |
GJ S- c 5 5 > |
u c f 5 |
b 2 i2 |
0 |
|
|
2 S* 2w |
-* C* CO <<* 'O |
O»^-00 5>C — C'lff5rJ''0?Oh.cpO |
O £ |
|||||||
|
0* <P |
[To be coptinued.]
XLIX. Oh
[ 281 ]
XLIX. On the native Gold Dust found in the Hills in the Environs of the Commune of St. George, in the Depart- ment of Le Loire. By Mr. Giuno, Prefect of the De- partment of i lie Sesia*.
It has long been known that a great number of rivers and rivulets carry with them particles of native gold, of larger or smaller size ; that independently of the places where this metal is found in its matrix, it is disseminated in grains in their sands, as those of the Rhone, the Arriege, and the Ceze in France, and with us in those of the rivers Loire, Balthee, Cervo, Elbo, Mallon, and Orba, and of the rivu- lets Oropa, Oremo, Evancon, Vison, &c. It is equally known that tHere are persons who make it their whole busi- ness to search for this gold, who are called, in the language of the country, arpailleurs, orpaiileurs, or pailloteurs.
Mineralogists are not agreed respecting the origin of these gold grains : the older mineralogists, and Brochant among the moderns, maintain that this gold is washed by the currents from its native mines, commonly situated in primitive moun- tains. (C Native gold," says Brochant f, <c is found chiefly in primitive mountains, where it is met with in veins, and sometimes disseminated in the rock : it occurs also in allu- vial strata, where it is frequently wrought with advantage. The sand of several rivers is mixed with grains of gold, which are separated from it by washing. It is unquestion- ably evident, that the gold here is met with accidentally ; and that it is deposited by the water that has washed it away from its original situation, which was probably the same as is indicated above." — Others think that these me- tallic particles were originally disseminated in auriferous strata, in the very places where they are exposed to view, by great floods, or overflowings of the rivers, or that they have been washed into the latter by torrents in storms or heavy rains.
I do not mean to enter into the question at large. This I leave to the learned, whose chief study is the improvement
♦ From Journal <les Mines, vol. xx.
f Elementary Treatise on Mineralogy, according to the Principles of Frof. Werner, vol. ii.
of
282 On the native Gold Dust found in
of the science of mineralogy. My inductions go no further than the small number of researches I have made : yet I think I may venture to say, from the observations I am about to present to the reader respecting the locality and si- tuation of the native gold dust in the commune of St. George, that such dust is not always washed down from mines in the mountains by rivers. And if such were the primitive origin of their dissemination amid the strata* it certainly could have happened only at some very remote period of the grand disruptions that have taken place on the surface and ex- terior of the strata of our globe. But these revolutions, of which we have no records, are buried in the night of time. For we shall see that strata which furnish gold dust are found at a considerable depth in some hills, equally remote from mountains capable of furnishing it, and from rivers that could force it from its native situation. It could, there- fore, have mingled in them only at a remote period, when the strata of the hills assumed the arrangement they have at present, namely, at the time of their formation.
This has been the opinion of several naturalists of our country, and I should be guilty of injustice to them, if, in collecting fresh proofs tending to support their hypothesis, I omitted to mention their valuable works. Accordingly I shall quote Mr. de Robillant, who, speaking of the gold dust found in the sands of the Oreo, says very positively : " This river carries along gold, which the people of the country observe only below the bridge down to the Po ; which confirms the opinion held by the people best ac- quainted with the natural history of the country, that it is from the gullies and hills that this gold dust is washed down into the river by the rapidity of the water during storms *. This valuable metal does not come from the high moun- tains, since none is found above the bridge ; but it originates from the washing of the red earth, of which most of these hills and plains are composed, and which in stormy weather is carried down into the principal river f."
* See a geographical Essay on the Continental Territories of the King of Sardinia, by de Robillant, in the Memoirs of the Royal Academy of Sciences at Turin for 1784-5, part ii. p 234. f lb. p. 268.
Mr.
the Department of Le Lobe* 283
Mr. Balbo agrees with M. de Robillant respecting this species of native gold, in his learned Memoir on the auri- ferous sand or' the Oreo. u Every one," says he, M knnw3 that gold dust is collected in the Oreo. — But I do not believe it is equally known, that gold is found, not in the bed of the river alone, but to the distance of several miles, every where mingled more or less with the sand. — It is very posi- tively asserted that it occurs in all the little rivulets between Valperga and Rivara. — I endeavoured to discover whether all the waters rise sufficiently near to each other to lead us to suppose that they equally derive their gold from the same mine ; as it is in this way that the vulgar, and even most of the learned, generally account for the gold found in rivers. But I was completely convinced that the waters of which I speak arise from different heights at some distance from one another; so that, as we cannot suppose all these places to contain mines, from which the gold may be de- rived, we must necessarily admit that the particles of gold are not separated daily by the action of the water, and car- ried along by its streams, but that the water finds them in the soil itself over which it flows. — And it is further con- firmed by the observation, that the auriferous strata disap- pear as we proceed up the Oreo; that we find them at furthest only as high as the bridge ; that above this all traces of ihem are lost, though this is very far from the springs; while as we descend into the plain these strata are everv day exposed by the. action of the water, and particularly in floods *."
In a second part I shall speak of the theory proposed by M. Napion, in his Memoir on the mountains of Canavaisf, who, having observed that all the pyrites of those mountains are auriferous, attributes the particles of gold to their de- composition or attrition. This is the opinion of our worthy colleague, Dr. Bonvoisin.
The observations I am now about to communicate appear to me still more decisive than the proofs alleged by these
* Mem. of the Roy. Ac. of Turin for 1781*5, on the auriferous Sand of Oreo, prrtii. p. 404—407. fJb.forl785-C, p.S45-G.
authors j
284 On the native Gold Dust found in
authors ; and if the earths of which I shall speak do not furnish so large a quantity of gold dust, they afford indisT putable proofs that the gold certainly does not proceed from any mine traversed by water, at least in the present day.
In the north of the commune of St. George, in the cir- cle of Chivas, in the department of the Loire, we find fer- tile rising grounds^ and hills almost wholly covered with vineyards, which continue till we come to the highest of them, the hill of Macugnano, part of which is cultivated, part covered with wild chestnut trees ; a distance of about three miles. — In our progress from the outer and upper sur- face of these hills to the bottom of the valleys, which inter- sect them in different directions, we find in general three very distinct strata. — The upper stratum is for the most part argillaceous, as it furnishes an excellent earth for making bricks and tiles. The thickness of this stratum varies in different places from three or four feet to twenty- five or thirty. The second stratum, which stretches likewise hori- zontally beneath the stratum of clay, is a few feet thick. It is composed of a considerable portion of sand, of gravel, and of pebbles of different natures, argillaceous, calcareous, and quartzose. Of these I shall speak more particularly in the second part, as well as of the fragments produced by their being broken or decomposed. The third or lower stratum, which forms the bed of the valleys, and of the rivulets that Tim through them, in rainy weather, is composed in great measure of the fragments of the argillaceous and calcareous stones of the second stratum. — The rains have gradually produced little gullies in different directions ; which by the falling of fresh rain, and the quantity and rapidity of the water, have in the course of time been extended and con- verted into valleys, more or less broad and deep, in different places. Part of the water of several gullies accumulates par- ticularly in one valley, where during storms and long rains it forms a torrent, called in the country the Merdanzone. Now the gold dust is found chiefly among the sands of this torrent, and of the small lateral rivulets that flow into the Merdanzone or other similar valleys.
Does this gold proceed equally from the different strata I
have
the Department of Le Loire, 285
have mentioned above, or from one of them only ? I first examined the brick earth (that of the upper stratum) in different places and at various depths : I also examined con- siderable depositions of this earth accumulated in the shallow valleys : but f never discovered the smallest particle of gold in it. The searchers for gold know this so well by long ex- perience and a great number of fruitless trials, that they never pay any regard to this stratum. It is the stratum be- neath the argillaceous composed of gravel, sand, micaceous and calcareous stones, in which the particles of gold arc found.
Of this I have convinced myself by several trials : and though in general, if equal quantities of earth be taken from this stratum, and from the bed of the torrent or rivulets flowing into it, the latter will yield most gold, it seldom or ever happens that no gold is found in the former upon trial. The particles of gold obtained from the auriferous stratum itself, which have not yet been rolled along with the sand by the rains, have a duller and deeper yellow colour thau those collected in the bed of the torrent or of the rivulets, which arc of a more shining yellow, no doubt in conse- quence of the attrition. They are generally found amid a sand that is more or less fine and blackish, and apparently of a siliceous and ferruginous nature. The earth of the same nature, which reaches to some distance, equally contains gold. Thus a brook that runs on the east of the commune of Aglie, between ihe mansion and the park, and receives the rain water that washes down an earth composed of dif- ferent strata of the same nature as those of the auriferous hills of St. George, equally rolls along particles of gold disseminated beneath the argillaceous stratum, which in some places is of very considerable thickness.
between fifteen and twenty years ago several persons in the commune of St. George made it their principal em- ployment to search for gold in the sand of, the torrents and rivulets that I have mentioned. This they did particularly after or during heavy rains, and after storms.
The quantity of gold they collected in a day was very va- riable. Sometimes each of them would gain eight or ten
shillings
2S6 On the native Gold Dust found in Le Loire*
shillings a day, at other times scarce a fourth or fifth of this sum. The size of the particles too varied much, from an almost invisible atom to the weight of nine or ten grains or more. They were afterward sold to merchants, who sent them to the mint.
I do not speak here of gold dust disseminated in arable land. Earth of this kind in the territory of Salussole, as I am informed by my colleague Giobert, contains particles of gold. The earth oF gardens is known to contain them. It has been proved in our days by the experiments of Sage, Bertholiet, Rouelle, Darcet, and Deyeux, that there are particles of gold in vegetables. Bertholiet has extracted about 2*14 gram. (33 grs.) from 48900 gram, or a hundred weight of ashes.
Gold has not yet been found in the arable land in the en- virons of St. George, but only in the stratum beneath the clay, the surface of which is cultivated. The auriferous stratum, as I have observed, is more than thirty feet deep below the argillaceous stratum in some places.
We have nothing to do here with particles of gold mixed with the surface mould by the decomposition of plants, or which plants have derived from the earth. I have no doubt that the particles of gold found in the environs of St. George have the same origin as those met with from Pont to the entrance of the Oreo and of the Mallon into the Po, from Valperga and Rivara, to Aglie and St. George's ; as well as of those which Dr. Bonvoisin observed in the en- virons of Challant in the valley of Aoste. The famous piece of native gold preserved in the arsenal was found there. In that space, pieces of gold of the weight of a louis have sometimes been found ; and other pieces are mentioned of the value of more than lOOlivres (l/. 35. 4d.). Probably the gold found in the earth in the valley of Brozzo, and in other places, has the same origin. My conjectures on this sub- ject shall be proposed in the second part of this memoir, where the nature of the earths and stones of the auriferous strata, as well as the nature of the land in which they are contained, shall be entered into more at large.
h. Some
[ 287 ]
L. Some Circumstances relative to Merino Sheep, chiefly collected from the Spanish Shepherds, who attended those of the Flock ofPaular, lately presented to His Majesty by the Government of Spain; with Particulars respecting that great National Acquisition ; and also respecting the Sheep of the Flock of Negrete, imported from Spain by His Ma- jesty in the Year 1791. By Sir Joskph Banks,
[Concluded from p. 248.]
In the year 1787 the king, guided by those patriotic mo- tives which are ever active in his majesty's mind, gave orders for the importation of Merino sheep for his own use, and for the improvement of British wool. As it was doubtful at that time whether the king of Spaiu's license, without which these sheep cannot be embarked at a Spanish port, could be obtained, it was deemed advisable to make the first purchases in the parts of Estremadura adjoining to Portugal, and to ship the sheep for England at Lisbon. The first im- portation of these valuable animals arrived in March 1788, and a little flock of them was soon after completed ; but as these were of various qualities, having been drafted from different Cavanas, his majesty was pleased to order an ap- plication to be made to the king of Spain by lord Auckland, then his majesty's minister at that court, for permission to import some sheep drafted from one of the prima piles. This was obtained ; and a little flock, consisting of 36 ewes, 4 rams, and 1 manso, arrived safe and well at Dover, in 1791. These sheep had made apart of the Cavana called Neiirete, one of the three piles restricted from exportation, and which is likewise remarkable for producing the larsrest- carcased sheep that are to be found among the Merino flocks, m, has been before stated.
On the receipt of this treasure, (for such it has since proved itself to be,) the king, with his usual prudence and foresight, ordered the whole of the sheep that had been procured bv the way of Portugal to be disposed of, (which was imme- diately done,) and directed the Negrete breed to he increase *: as much as possible, and maintained in its utmost purity.
2 From-
283 Some Circumstances relative to Merino Sheep.
From that time to the present the opinion of the public, sometimes perhaps too unwary, and at others too cautious, in appreciating the value and adopting the use of novel kinds of sheep, has gradually inclined to give that preference to the Merinos which is so justly their due. At first it was impossible to find a purchaser willing to give even a mode- rate price either for the sheep or for their wool ; the shape of the sheep did not please the graziers, and the wool-sta- plers were utterly unable to judge of the merit of the wool, it being an article so many times finer and more valuable than any thing of the kind that had ever before passed through their hands. The butchers, however, were less ti- morous \ they readily offered for the sheep, when fat, a fair mutton price; and there are two instances in which, when the fat stock agreed for was exhausted, the butcher who had bought them anxiously inquired for more, because he said the mutton was so very much approved of by his best cus- tomers.
It was not, however, till the year 1804, thirteen years after their first introduction, that it was deemed practicable to sell them by auction, the only certain means of placing animals in the hands of those persons who set the highest value upon them, and are consequently the most likely to take proper care of them. The attempt, however, succeeded; and the prices given demonstrated that some at least of his majesty's subjects had at that time learned to put a due value on the benefit his royal patriotism offered to them. One of the rams sold at the first sale for 4£ guineas, and two of the ewes for 1J guineas each; the average price at which the rams sold was 19/. 4s., and that of the ewes 8/. 1 5.?. 6d. each*
This most useful mode of distribution has since that time been annually continued, and the sales have taken place in the beginning of August. The last sale was held on the 17-th' of August, 1808, when the highest price given for a ram was 74/. lis., for an ewe 38/. 17s. The average prices of rams was 33/. 105. \d., of ewes 23l. 125. bd. ;— a most decisive proof not only that the flock had risen very mate- rially in public estimation, but also that the sheep have not in any way degenerated from their original excellence.
The
Sbme Circumstances relative to Merino Sheep. 289
The wool was at first found to be quite as difficult of sale as the sheep themselves ; manufacturers were therefore em- ployed to make a considerable quantity of it into cloth, which, when finished, was allowed by both woollen-drapers and tailors to be quite as good as cloth made of wool im- ported from Spain. But even this proof would not satisfy the scruples of the wool buyers, or induce them to offer a price at all adequate to the real value of the article : it was found necessary, therefore, to have the wool scoured, and to sell it in that state as Spanish wool, which, though grown in England, it really was. Thus managed, the sales were easily effected for some years, at a price equal to that de- manded for the prima piles of imported Spanish wool at the times when the bargains were made.
Time and patience have at last superseded all difficulties, and his majesty's wool has now for some years been sold as clipped from the sheep's backs, the sheep having been washed, and the whole management of them carried on ex- actly in the English manner, at a price not lower than 4s. 6d. a pound, which, allowing for the loss of weight in the scouring, costs the buyer at least 5s. 6d. a pound, a tole- rable price for Spanish wool when plenty of it could be pro- duced, though not possibly so high an one as ought to have, been given or as will be obtained for the Anglo-Negrete pile, when the value of the article is fully understood. <• The race of another capital Cavana has now been added to the riches of this country, the Paular, and the draught from it is larger than on any other occasion has been suf- fered to leave Spain ; the animals have been selected with skill and attention, the pile they belong to stands at the very top of our English list, and the sheep have been most for- tunately placed at the disposal of our most gracious king, whose shepherds have demonstrated to the public, in an ex- perience of 17 years of their management of these interesting animals, that they can not only continue the breed in its original purity, but can also preclude all danger of degene- ration in the article of wool. What more can be wished for on this head ?
That spirit of patriotism, which induced our sovereign to Vol, 33. No. 132, April 1S09. T declare
«90 Remarks on M. Burckhardt's Contrivance
declare himself the protector of the purity of the Negrete race, will also, it is most earnestly to be hoped, induce his majesty to extend the same protection to the newly arrived Paulars ; by this measure, and by this alone, the public will be effectually guarded against all danger of the admission of impure blood, which the avarice of ill-judging individuals, seeking alter a premature improvement of the carcase, has too often, it is feared, introduced into our English flock.-. Thus protected, the twofold treasure obtained for the advan- tage of his subjects by his majesty's wisdom and foresight, will become a perennial fountain of true Merino blood, to which those agriculturists who are wise enough to adopt the breed may from time to time resort, to correct their errors if they fall into bad practices, to carry on their crosses, if any such are found to be advantageous, to the highest degree of perfection, and to restore the originality of their stock,, if, in consequence of any unsuccessful experiment, it should have suffered deterioration.
LI. Remarks on M. Burckhardt's Contrivance for shorten- ing Reflecting Telescopes ; with a new Method of making Refracting Telescopes with a Tuhe only one-third of t/u focal Length of the Ohject- glass. By David Brewster, LL.D. F.R.S., and F.A.S., Edin.
DEAR SIR, *
In the Conjiaissancc des Terns for 1809, I observe the de- scription of a new telescope, invented by the celebrated M- Burckhardt, of an intermediate nature between the Gregorian and Newtonian telescopes; and requiring a tube only halt as Ions: as other instruments of the same focal length. The large concave speculum AB, Fig. I, (Plate IX.) is perfo- rated as in the Gregorian telescope, so that the diameter of the aperture ef may be half the diameter AB. The parallel rays Rm, R//, which, after reflection, would have formed the image atF, are intercepted by a plane speculum C, per- pendicular to the axis of the telescope, and of the same size as the aperture ef and are reflected back to the point o,
whepf
for shortening Reflecting Telescopes, &c. 291
where an image is formed, and viewed with the eye-glass G. By giving a small inclination to the plane speculum, the image may be formed at A, above the speculum, without a perforation in its centre.
The merit of this invention does not exclusively belong to the French astronomer. The same principle was employed in the construction of the reflecting telescope more than six years ago by Mr. Paterson, who had then the management of the Observatory at Edinburgh, and instruments con- structed in this manner were advertised for sale in that city.. In order to try the performance of a telescope made on this principle, I constructed a small one several years ago, with- out perforating the concave speculum ; but the great loss of light when the plane speculum intercepted the incident rays that would otherwise have fallen on the central and the most perfect part of the concave one, and the distortion of the image when the great speculum was inclined a little and the plane one placed out of the incident rays, induced me to think that the convenience which arises from shortening the tube could by no means compensate for the disadvantages with which it was necessarily attended. This was also the opinion of the late celebrated Dr. Robison, to whom Mr. Paterson showed one of his new telescopes. M. Burckhardt, however, seems to think that the advantages resulting from shortening the tube greatly preponderate ; and that the loss of light, which I have before stated, may be remedied by en- larging the aperture of the concave speculum. The Board of Longitude at Paris have seconded the views of M. Burck- hardt, and have ordered a telescope to be constructed on the principle already described.
As this subject has been taken up by the French astro- nomers, it may not be uninteresting to give an account of two -.other contrivances which have occurred to me for shortening the tubes of telescopes. If instead of the plane Speculum C, we substitute a convex one so as to form an image at O, the telescope becomes Cassegrainiam, requiring a tube only about one- half the focal length of the concave speculum. This construction is preferable to that which is described by Surckhardt ; because it is much easier to give a
T % correct
J92 A Reply to Earl Stanhope, on his Defence of
correct figure to a convex than to a plane speculum ; and it is well known to practical opticians, that the errors of one spherical speculum often correct those of the other.
If any real advantages arise from shortening the tubes of reflecting telescopes, it becomes a matter of importance that refracting telescopes should possess similar properties. By means of the following, contrivance the tubes of refractors may be so much shortened as to be only one third of the focal length of the object-glass. A plane speculum CD, whose diameter is two-thirds of that of the object-glass AB, is so placed that CA is one-third of the focal length of AB. By giving a small inclination to CD, the rays are reflected to a second plane speculum EG, equal to one-third of the dia- meter of AB, which again reflects the incident rays to F, where the image is formed and magnified by the eye-piece. In this construction, the only disadvantage is the loss of light occasioned by two reflections ; but this may be obviated by increasing the aperture of the object-glass, and is by no means such a serious evil as that which arises in M. Burck- hardt's contrivance, from the loss of such a large central portion of the great speculum.
I am, dear sir, your most obedient servant,
D. Brewster.
To Mr. TillocJu
LI I. A Reply to Earl Stanhope, on his Defence of certain Principles and Facts erroneously stated in his Stereotyped " Principles of the Science of Tuning Instruments with fixed Tones." By Mr. John Farey.
" The difference between a man of real science, and one who has the ain- bition So be thought so, is very great." — Earl Stakhof-e.
JL h:
To Mr. Tilloch, — Sir,
ie truths and principles of the Mathematical Sciences are not in any instance to be yielded to authority, however imposing its aspect; neither should we suffer any other con- siderations, long to restrain our efforts, in defending their
just
his Principles for Tuning Instruments, £s*c. 293
just cause. It has been purely out of regard and tenderness to the unfortunate situation of a musician of the very first rank, whose mental aberrations had been much aggravated by the part he was led to take, and made appear to act, in explaining and defending a noble Earl's reveries on the sub- ject of Tuning musical Instruments, that I have been so long kept back from replying to such parts of the two Letters of Earl Stanhope, printed in your Magazine (vol. xxviii. p. 144, and xxx. p. 34,) as relate to the scientific principles of Tuning: and similar feelings towards the very respectable individual alluded to, alone induce me to refrain from again touching on the two " Plain Statements," and the " Narra- tive," further than to declare, as injustice to Dr. C.'s mu- sical reputation I think I ought, that he never, I believe, perused or saw the Stanhopian " Plain Statement," mention- ed by His Lordship in vol. xxx. p. 25, previously to its pub' licaiion*, except in the hands of Mr. Ferguson, from whom he refused to take tlie proof sheets, or look at them : but, as Mr. F. himself told me, directed him to take them again to the printer ; intending, as he (Dr. C.) has often told me, that His, Lordship should be responsible for what he had written and got printed, and not suspecting, under the cir- cumstances, that the name of J. W. Calcott would be affixed to it when published. After this, there needs no more for me to say at present, than request those who happen to have the two pamphlets, to compare them together, as the worthy and unfortunate Doctor intended, by stitching up and distributing them, as I mentioned in a former communication.
There are six questions touched upon in His Lordship's two Letters referred to, on each of which I wish to be in- dulged in saying a few words : — these are shortly, 1st, Whether a monochord board should be divided into 120
or 100 parts ? 2d, Whethe.^the difference of the lengths of string, can a$-
curately measure the interval between the sounds of two
strings, of the same size, weight, and tension ?
-V Indeed I saw Dr. C. write a Note to you, Sir, to this effect, in February 4S0S, with an intent that you should publish this fact in your Magazine.
T3 3d,
29 L A Reply to Earl Stanhope, on his Defence of
3d, Wh et her four or jive columns are to be found in page*
7 and 22 of the Stereotype pamphlet ? 4th, Whether the intervals called the four tierce wolves are of
the same or different magnitudes ? 3th, Whether equal temperaments of successive concords of the same kind, produce equality in the rates of their heating P 43th, Whether the notation of musical intervals generally, by S, f and m, rather than by their most simple ratios, be analogous to substituting a notation by scores} dozens, and odd, in place of the universally received decimal nota- tion $
I. — In addition to the reasons I have given at page U)2 of vol. xxvii., for preferring a decimal division of the mono- chord, I have further to remark, on what has fallen from His Lordship (page 144 of vol. xxviii.) that those :J impor- tant lengths" which His Lordship's scale is calculated to show in round numlers, are perfectly unimportant ; for, what person using a monochord, other than as a play-thing, wants to use the scale attached to the string at all, in tuning a. perfect concord of any kind ? And does not the use of its ocale as a tuning apparatus wholly consist, in either setting or taking oft tempered intervals P And whether is it easiest, to set a triequal quint for instance, on a decimal scale by my number '6694329, or on His Lordship's scale of 120, by
means of his vulgar tractions y^^^o- (Stereotype page
71,70,247,502 -f /A \l_
^°f i07,10,92728o+(DP- 21)?
II. — I have maintained (and am backed by all mathema- tical writers) that it is ratios only, and not lengths, except of such things as in their nature measure ratios, as logarithm scales 8cc. do, that can define musical intervals. And though His Lordship expressly asserts (p. 145, vol. xxviii.) that " deviations from perfect intervals are concisely, as well as accurately and conveniently expressed, by means of ihe difference of the lengths of wires," I shall take the very example which he alludes to, (Stereotype p. 8,) wherein it is said, that 1*44 the difference o*i two strings, of which the
octave
his Principles for Tuning Instruments, &c. 293
octave length is 120*00, " shows the value" of the tierce
144 wolf; in order to show, that r^^? instead of expressing
anjnterval called the enharmonic diesis (21 2 + 2 m) as it ought to do, represents an interval exceeding 6 octaves by a superfluous third (3905 2 + 77 f -f- 338 m) !
III. — Five columns certainly appeared to my eyes, when I was commenting on the Stereotype pages 7 and 22, there- fore, unluckily it should seem, I mentioned Jive; but have I anywhere said or insinuated, that His Lordship therefore intended to representee wolves, besides that produced by the quints ? And I could not myself have intended to re- present five such wolves, when his Lordship is severe upon me for saying there are but two in all. His Lordship's sar- casms, about dividing 1 2 into 5 aliquot parts, might there- fore have been spared.
IV. — My arguments for the exact equality of all His Lordship's four tierce wolves, (at page 200, vol. xxvii.) re- tain their force, and are not invalidated by what His Lord- ship has advanced at page 149, vol. xxviii. ; where, fortu- nately, His Lordship has let us into the secret of his blun- ders in this respect, by the mention of " monochord lengths," showing, that when His Lordship argues for as complete a distinction between his tierce wolves, as to magnitudes, as between half-guineas, half-crowns, sixpences, and half- pence, he had no better ground than their different lengths on the monochord ; forgetting what T had endeavoured to impress on him, under the second head above, as to the fallacy of these lengths as a test of the magnitudes of inter- vals. Gould not His Lordship as easily " distribute" or di- vide the same interval in four different ways in his C G D and A columns, as he can so distribute four different inter- vals? unless he confines his idea of equality, to mono- chord lengths, as then of course, they would only fit where the octave and thirds are also of the proper proportionate lengths ! Absurdities, to which His Lordship surely could not have turned his attention.
V. — I did think it possible, when writing my observa- tions page 201 to 203, vol. xxvii., that slips of His Lord-
T4 ship'0
&96 A Reply to Earl Stanhope, on his Defence of
ship's pen had occasioned his appearing to advance a doc- trine, so opposite to all that had heen demonstrated by Dr. Smith, Dr. Robison, and a host of other mathematical writers ; but his defence of the same in pages 150 to 152, vol. xxviii., precludes any such charitable suppositions in fu- ture. The scientific terms, or rather the " scientific jargon/' of His Lordship, I certainly do not understand, if by that he means, that I am to receive them, in opposition to the authorities above quoted, by whom His Lordship was cer- tainly not " obliged to use" his new terms, for, they have uniformly and consistently used pulses or vibrations for what His Lordship would now for the first time call beats ; and what he would exclusively call beatings they have gene- rally called beats, but have sometimes used beatings as sy- nonymous therewith.
Before His Lordship took pen in hand on this subject, I well knew that the rate of beating increased along with every increase of the imperfection of a consonance ; but His Lord- ship is the only one I ever heard assert, that it increases " As the imperfection increases " which is no more true, than that the sine of an angle increases as the angle increases, or that gravity increases as the distance decreases. His Lordship refers (page 151,) to an example, and attempts to prove, that the triequal quints DA, one an octave above the other, beat equally quick : let us therefore see what evidence numbers furnish in this case. By referring to my table in page 5, vol. xxx. it will appear, that the two D's vibrate or excite 134*44 and 268*88 complete pulses in the air in one second of time respectively, and the two A's 200*83 and 401*66 pulses respectively, and by using these in the proper theorem for the purpose, we get 1*666 beats per second made by the lower, and 3*333 beats per second by the upper of these tempered or tri-equal quints ; the one just double of the other, instead of their being equal as our noble author has maintained ; and thus we see, that no " beating between the two beatings" could in this case happen even in theory, and certainly none in practice could be expected ; for who besides Earl Stanhope ever talked of hearing beatings, be- tween two noises which themselves occur but If and 3^
times
his Principles for Tuning Instruments, &c. 297
times per second ! or not above one-eighth of the rate neces- sary to constitute continuous or musical sound? In the case of equally tempered intervals, situate at the exact di- stance of any of the concords from each other, it is gene- rally true, that no " beating between the beatings" either in theory or practice can happen. Suppose for instance, His
Lordship's minor sixth C A which is flattened about — parts
20 of a comma (not —• as printed by mistake p. 1 95, vol. xxvii.) ;
this in the middle septave beats 22*6335 times per second (or rather, in practice won't beat at all, but produce a con- tinuous third discordant note) : if we tune another similar or equally tempered sixth, on a note, a true minor sixth below C the bass of the former one, that is, on His Lordship's "first bass E : we shall find, that this will beat just 5-eighths as fast as the above, or 14*1459 times per second, but no u beating between the beatings" will take place, although each are quick enough to produce them, owing to their having the true relation of minor sixth between them, and not because they are unisons as His Lordship would contend. Let us, however, abandon the supposition of the tempered sixths having basses that are exactly at concordant di- stances, and tune just a similar minor sixth below C to that which His Lordship has above C, that is, take two of these 6ths in succession; then we shall find, the lower note E making 151*79 vibrations per second, and the 6th EC will beat at the rate of 14*3144 times in a second: which not bearing a true concordant relation to the beating of the upper 6th, the sounding of the two together will be found by calculation to occasion a <( beating between the beatings" at the rate of 1*3477 per second : thus we see, that a " beat- ing between the beatings" may happen to equally tempered concords : and the same will indeed always happen, in theory at least, to the tempered concords of which His Lordship treats (although His Lordship asserts the contrary) ; for all his tuning is to be performed by perfect intervals ex- cept two successive hiequal thirds, and three successive tri* equal quints, all of which will have such a " beating between
the
598 A Reply to Earl Stanhope, on Ids Defence of
the heatings," and of course so acute an observer as His Lordship cannot fail of perceiving them : and will be ne- cessitated to " beat" a retreat, out of the labyrinth of error into which he has with temerity advanced, instead of think- ing to " beat" his pretended " facts" and " important mu- sical truths" into me, or any one else who has the least pre- tensions to mathematical knowledge.
VI. — I have here to complain of the same superficial view of the subject, as His Lordship took when commenting on decimally divided monochords : the object of any general notation of musical intervals cannot be to represent the per- fect concords, as j i-, -f , 4 £, &c, more simply than they are already expressed, but for comparing inconcinnous inter- vals, such as His Lordship's biequal third for instance, with any other intervals : if we examine the i( important musical truths" in Stereotype with this view, what do we findj more than that the biequal third has an approximate ratio of
2,371,708.245 +,„„,,,,„„ 3,000,000,000
(page 23) ? If we wish to compare this with
the triequal quint for instance, whose ratio is stated in the
. 3,008,298,850+ , . ' .
same page, viz. 3-^,55^555-, and are desirous to learn
their difference or the interval remaining after the former is taken from the latter; in vain do we search the records of " musical truths" for the mode of accomplishing this. A novice, misled by the term " difference" in the last column of this page, might think his work easy, and attempt to give us the difference of these fractions, already reduced to a common denominator j for the purpose; but on discovering that the least interval had the largest numerator, here our tyro's exertions would probably end. One a little more ex- perienced would discover, that it is a ratio which is to be deducted, and recollecting his school rule for the division of fractions, would proceed to multiply the denominators and numerators together reciprocally, when after proper reduction,
.2,009,298,8.504- ! . VI- „ , „ ,
• 0.7! nci* oirj. would appear as the ultimate " truth to be come at. Now those who have done me the honour, of attending to 2 the
, his Principles for Tuning Instruments, &c. 299
the new notation vol. xxviii. p. 142, would at once discover, that 35.4J S 4- 7 f + S0| m, and 207-^ S + 4f + 18ra, represent the triequal quint and biequal third respectively, and that the difference of these, or 146-j;- £ + 3 f + 12$ m, admits of an immediate comparison with all the various in- tervals in the tab'e in plate V. of the same volume. One simple subtraction would further show it to be, a minor third flattened 14 * 2 -f 1 V m, or 2£ 2 + ± m more than the diaschisma orqnint-wolf of our noble author: and hundreds of instances might be shown, wherein this notation gives still greater facility to the comparison of intervals with very complex ratios, than it does in the above case ; but can His Lordship show a single instance (except the well-known and useful process of reducing large numbers of pence to pounds, shillings, and pence, for some purposes be considered such,) wherein his ingenious notation by scores, dozens, and odd would possess any advantage over decimal arithmetic? ana- logous to the conversion of simple ratios by the new notation into three elementary ratios (or two in some cases) which I have effected for the general comparisons of intervals ? or, can his sapient approvers make out, similar advantages to result from their " cubit " and i( measuring rod of Ezekiel," for expressing the Lapland degree ?
I have not dropped my design of entering at some future time on a comparison of His Lordship's monochord and equal-beating systems, with the systems of other writers, particularly those which His Lordship has in so summarv a way condemned, as I originally proposed, by the help of a table of the temperaments and beats of every concord which can arise in each system respectively; and as I am kindly assisted in the labour of these calculations, by a gentleman of more leisure than myself, with whom His Lordship is well acquainted, he has in the mean time the opportunity through him, of himself anticipating my intended comparisons, and of giving, any further support to his systems, which such comparative evidence will warrant.
I am, sir, your obedient bumble servant,
John Farey.
,12, Upper Crown Street. Westmii March 14, 1609,
LIIL On
[ 300 ]
LI II. On the Motion of floating Bodies in running Water, By Peter Barlow, Esq., of the Rcyal Military Aca- demy, Woolwich,
To Mr. Til loch , — Sir, In your Magazine for March, I have observed a letter from Mr. G. Or, wherein he endeavours to account for some par- ticular circumstances in the motion of floating bodies in ' running waters, that have been noticed by Capt. Burney, and which, it seems, formed the subject of a paper that was read before the Royal Society. In order to accomplish this, Mr. Orr has called in the assistances of the inclined plane, and the doctrine of gravity, or, as he calls them, the laws of matter and motion. Mr. Orr will excuse me, at least I hope so, when I inform him that he does not seem to compre- hend what those laws are. He is not, perhaps, aware that, in the sense that he attaches to them, he is reviving the old exploded notions of Aristotle, which ever since the time of Galileo have been known to be erroneous : — that celebrated philosopher proved that, by the law of gravity, all bodies, whatever their magnitude and density may be, fall through equal spaces in equal times ; and when this is not the case, it arises from those laws being counteracted by some other force .Thus in the case given by Mr. Orr, of two globes of equal magnitudes and different densities rolling down an in- clined plane, were thev left solely to the action of gravity, — ■ for instance, had the experiment been made in vacuo, they would both have descended in the same time; and the reason they do not in ordinary experiments, is because the force of gravity is counteracted by the resistances of the atmosphere; for, both bodies having equal dimensions, they experience equal resistances in their descent, and consequently that body which oppose? the greatest force to this resistance, that is, the heaviest body, will descend with the greatest velocity. We see, therefore, that instead of gravity being use of the different rales of descent of the two bodies, the circumstance must be attributed to its laws being coun- teracted. Mr. Orr is not less mistaken, in considering this as a parallel case to two bodies floating in running water;
for
On floating Bodies. 301
for in the former case the bodies move through a medium which is perfectly at rest ; and in the latter the medium it- self is in motion, and is the cause of the motion of the bodies.
Having thus, I think, satisfactorily shown that Mr. Orr's laws of matter and motion are not sufficient to account for the circumstance alluded to by Capt. Burney, I will venture to offer mv own conjectures on this subject ; — but this I do with considerable diffidence, and soliciting a correction of any errors that may be discovered therein by any of your ingenious correspondents.
Let us then suppose the case of a beam of timber loaded at one end ; and let us conceive that in the first instance the beam moves parallel to itself, or that the velocities of the two ends are equal : then it is evident that the heaviest end will acquire the greatest momentum, and consequently, if the beam should experience any resistance in its motion, that end of it which possesses the greatest momentum will oppose that resistance with the greatest effect, and will thus be thrown foremost ; and this will continue to be the case, till its direction coincide with that of the stream.
What the resistance is that the beam experiences, and from what cause it arises, are not difficult to determine. In such a river as the Thames, where the experiments were made, and where the tide is constantly ebbing and flowing, every particle of water cannot be supposed to move with equai velocities; small eddies, contrary currents, and va- rious other circumstances will prevent that uniformitv, though perhaps they may be imperceptible to the eye of even an attentive observer. This being the case, if the beam should be struck by any particles of water moving in a con- trary direction, or should the beam strike any that are at rest, or moving in the same direction as itself, but with a less velocity, any of these circumstances will oppose a re- sistance to the motion of the b< am, which it has been shown will be more effectively overcome by that end of it which has the greatest momentum. And in a similar manner we aiav account for the motion of the two barges.
Should
302 Memoir on the Formation of the Phosphoric Ether,
Should these conjectures he thought deserving of a place in your next Number, they are very much at your service.
Yours, Sec, April?, iso9. Peter Barlow,
LIV. Memoir upon the Formation of the Phosphoric Ether, by Means of a particular Apparatus. By M. Boullav, Chemist, in Paris. — Read to the First Class of the Na- tional Institute the 23d of March, 1 807 *.
Ocheele and Lavoisier had repeatedly tried without suc- cess, to transform alcohol into ether, by the action of the phosphoric acid ; when at last M« Boudet jun., an apothe- cary of Paris, published u Memoir upon the subject, in tome xl. of the Annales de Chimie. The phenomena which he describes announce a real action between the acid and the alcohol, and manifest several circumstances .which ge- nerally accompany the process of etherification: According to his own admission, however, the produce he obtained was not very volatile, totally insoluble in water ; and although it.had a peculiar smell, it did not present the characters of a true ether.
Convinced bv various trials that the want of action of the concentrated or even vitreous phosphoric acid upon alcohol, was particular! v owning to the difficulty of uniting these two substances, of multiplying and prolonging the contact of their reciprocal molecules, I resumed the experiments, and the hope I entertained of attaining a more satisfactory result was realized by the following experiment : —
To a tubulated retort placed upon a saudbath, I adjusted a bell-glass also tubulated, which communicated by aWeU ter's tube of safety with a flask filled with limewater. From this flask issued a second tube which proceeded under a bell- glass attached to ihc hydro -pneumatic apparatus.
I introduced into the retort 500 grammes of pure phos- phoric acid, resulting from the combustion of phosphorus
• I -.. • :),< Chhrdr, rome hii. p. i?.\
by
vy Means t)fa particular Apparatus. 303
by the nitric acid, vitrified, redissolvcd, and reduced by evaporation to the consistence of' honey.
I afterwards placed upon the tubulure of the retort an in- strument of glass, which may be called the reservoir, of an oblong form, open at both extremities, each of which may be made perfectly air-tight by means of a stop-cock. From the lower extremity issued a tube which descended to the bottom of the retort, and entered into the phosphoric acid. The upper extremity surmounted by a funnel, the commu- nication between which and the reservoir might be inter- rupted, had also a smali aperture with a ground stopper, in order to let out the air when it was displaced by a liquid. (See Plate IX. Fig. 3.)
The apparatus being thus arranged, carefully luted, and the first receiver cooled bv a mixture of ice and sea salt, afire was lighted under the retort, increasing it gradually so as to heat the acid to 95 degrees of Reaumur. Five hundred grammes of alcohol at 40 degrees were then introduced into the reservoir, and, by means of the lower stop-cock, drawn drop by drop through the phosphoric acid warm and liquid. The mixture took place with great effervescence : it was coloured black, and abundant streaks immediately covered the arch and neck of the retort.
The fire was kept up, and distillation continued to dryness :
There passed into the bell-glass :
1. One hundred and twenty grammes of alcohol feebly etherized.
2. Two hundred and sixty grammes of a white light liquor, of a lively smell, and much more etherized than the lirst.
3. Sixtv grammes of water saturated with ether, and on which four grammes of a lemon-coloured fluid floated of an
to
cmp\ reumatic smell, very analogous to that which corner after the sulphuric ether, and which is commonly distin- guished undcr4he name of sweet oil of wine.
4. Another liquid of a foetid insupportable smell, redden- ing turnsole tincture, and uniting with cfTcrvescence with the carbonate of potash. This combination evaporated to dryness was a deliquescent scaly wh, perfectly resembling acetate of potash.
Lime-
304 On the Formation of the Phosphoric Ether, &c,
Limewater became turbid, but not until after the distil- lation was over.
Besides the air in the vessels, a gas of a pungent smelf was collected, which burned with a white flame, depositing upon the sides of the bell-glass a very abundant charry coat- ing : this was a little ether which had escaped condensation, passed over at the same time with the most etherized liquid product, and a little before the white vapours which an- nounce the presence of oil.
There remained in the retort a vitreous blackish substance, composed of phosphoric acid and a little charcoal.
The two first products united, of the weight of 380 gram- mes, rectified over dry muriate of lime at a heat of about 50 degrees, furnished about 60 grammes of a liquor having the greatest possible resemblance, in point of smell and taste, to the purest sulphuric ether. Like the latter, it marked 60 degrees in Baume's areometer, the thermometer being at 10°; it was dissolved in eight or ten parts of cold water, was ra- pidly evaporated in the air, entered into ebullition at thirty degrees of temperature, dissolved the resins and phosphorus, burned with a whitish flame, leaving a charry residuum, and without any trace of acid having been exhibited by its com- bustion over the surface of water.
The other products of the rectification were alcohol slightly etherized : this alcohol when again passed, in the manner already shown, through the phosphoric acid used in the ex- periments, occasioned the formation of a new quantity of ether in every respect similar to the first*
It seems to result from the preceding facts, and from the examination of the above products,
1st, That the phosphoric acid can transform alcohol into a perfect ether by means of the apparatus which I used, and by attending to the precautions already described.
2dly, That the ether which results from the action of the phosphoric acid upon alcohol is, of all the ethers known, that which has the most analogy with sulphuric ether, both with respect to its properties and to the phenomena ob- served in its preparation.
LV. Me-
, "».*
[ 303 ] LV. tylemoirs of the late Erasmus Darwin, M. D.
[Continued from vol. xxxii. p. 336.]
DARWINIANA. . ,
JVJ.adness. — Tn every species of madness there is a peculiar idea either of desire or aversion, which is perpetually excited in the mind with all its connections. In some constitutions this is connected with pleasurahle ideas without the exertion of much muscular action, in others it produces violent mus- cular action to gain or avoid the object of it, in others it is attended with despair and inaction. Mania is the general word for the two former of these, and melancholia for the latter ; but the species of them are as numerous as the desires' and aversions of mankind.
In the present age the pleasurable insanities are most fre- quently induced by superstitious hopes of heaven, by senti- mental love, and by personal vanity. The furious insanities by pride, anger, revenge, suspicion. And the melancholy ones by fear of poverty, fear of death, and fear of hell ; with - innumerable others.
Cjuiajuid agunt homines, votum, timor, ira, voluptas, Gaudia, discursus, nostri est farrago libelli.
Juven. i. 85.
This idea, however, which induces madness or melan- choly, is generally untrue; that is, the objefct is a mistaken fact. As when a patient is persuaded he has the itch, or venereal disease, of which he has no symptom, and becomes mad from the pain this idea occasions. So that the objeet of madness is generally a delirious idea, and thence cannot be conquered by reason ; becaue it continues to be excited by painful sensation, which is a stronger stimulus than vo- lition. Most frequently pain of body is the cause of con- vulsion, which is often however exchanged for madness ; and a painful delirious idea is most frequently the cause of madness originally, but sometimes of convulsion. Thus I have seen a young lady become convulsed from a fright, and die in a few days ; and a temporary madness frequently ter- minates the paroxysms of the epilepsia dolorifica, and an insanity of greater permanence is frequently induced by the pains or bruises of parturition.
Vol. 33. 5sTo. 132. April 1809. U Where
306 Memoirs of Erasmus Darwin, M. D.
Where the patient is debilitated a quick pulse sometimes attends insane people, which is nevertheless generally only a symptom of the debility, owing to the too great expendi- ture of sensorial power ; or of the paucity of its production, as in inirntative, or in sensitive inirntated fever.
But nevertheless where the quick pulse is permanent, it shows the presence of fever; and as the madness then gene- rally arises from the disagreeable sensations attending the fever, it is so far a good symptom; because when the fever is cured, or ceases spontaneously, the insanity most fre- quently vanishes at the same time.
The stimulus of so much volition supports insane people under variety of hardships, and contributes to the cure of diseases from debility, as sometimes occurs towards the end of fevers. And, on the same account, they bear large doses of medicines to procure any operation on them ; as emetics, and cathartics, which, before they produce their effect in in- verting the motions of the stomach in vomiting, or of the absorbents of the bowels in purging, must first weaken the natural actions of those organs.
From these considerations it appears, that the indications of cure must consist in removing the cause of the pain, whether it arises from a delirious idea, or from a real fact, or from bodily djsease; or secondly, if this cannot be done, by relieving the pain in consequence of such idea or disease. The first is sometimes effected by presenting frequently in a, day contrary ideas to show the fallacy, or the too great es- timation, of the painful ideas. 2dly, By change of place, and thus presenting the stimulus of new objects, as a long journey. 3dly, By producing forgetfulness of the idea, or object, which causes their pain ; by removing all things which recall it to their minds; and avoiding all conversa- tion on similar subjects. For I suppose no disease of the mind is so perfectly cured by other means as by forgetfulness.
Secondly, the pain in consequence of the ideas or bodily diseases above described is to be removed, first, by evacua- tions, as vencscciion, emetics, and cathartics ; and then by large doses of opium, or by the vertigo occasioned by a cir- eulating swing, or by a sea-voyage, which, as they affect
the
Memoirs of Erasmus Darwin, M.D. 307
the organs of sense as well as evacuate the stomach, may contribute to answer both indications of cure.
Where maniacs are outrageous, there can be no doubt but coercion is necessary ; which may be done by means of a strait waistcoat ; which disarms tnem without hurting them ; and by tying a handkerchief round their ankles to prevent their escape. In others there can be no doubt, but that confinement retards rather than promotes their cure ; which is forwarded by change of ideas in consequence of change of place and of objects, as by travelling or sailing.
The circumstances which render confinement necessary, are: first, if the lunatic is liable to injure others, which must be judged of by the outrage he has already committed. 2dly, If he is likely to injure himself ; this also must be judged of by the despondency of his mind, if such exists. 3dly, If he cannot take care of his affair?. Where none of these circumstances exist, there should be no confinement. For though the mistaken idea continues to exist, yet if no ac- tions are produced in consequence of it, the patient cannot he called insane, he can only be termed delirious. If every one, who possesses mistaken ideas, or who puts false esti- mates on things, was liable to confinement, I know not who of my readers might not tremble at the sight of a mad- house !
The most convenient distribution of insanities will be into general, as mania mutabilis, studium inane, and vigilia ; and into partial insanities. These last again may be subdi- vided into desires and aversions, many of which are suc- ceeded by pleasurable or painful ideas, by fury or dejection, according to the degree or violence of their exertions. Hence the analogy between the insanities of the mind, and the convulsions of the muscles described in the preceding genus, is curiously exact. The convulsions without stupor, are either just sufficient to obliterate the pain which occasions them ; or are succeeded by greater pain, as in the convulsio dolorifica. So the exertions in the mania mutabilis are either just sufficient to allay the pain which occasions them, and the patient dwells comparatively in a quiet state ; or those exertions excite painful ideas, which are succeeded by fu- ll 2 xious
]\femoirs of Erasmus Darwin, M.D. rioils discourse?, or outrageous actions. The studium inane, or reverie, resembles epilepsy, in which there is no sensi- bility to the stimuli of external objects. Vigilia, or watch- fulness, may be compared to the general writhing of the body; which is just a sufficient exertion to relieve the pain which occasions it. Erotomania may be compared to tris- rims, or other muscular fixed spasm, without much subse- quent pain ; and mceror to cramp of the muscles of the leg, or other fixed spasm with subsequent pain. All tbese coin- cidences contribute to show, that our ideas are motions o* the immediate organs of sense obeying the same laws as our muscular motions.
The violence of action accompanying insanity depends much on the education of the person *, those who have been proudly educated with unrestrained passions, are liable to greater fury ; 'and those whose education has been humble, to greater despondency. Where the delirious idea, above described, produces pleasurable sensations, as in personal vanity or religious enthusiasm, it is almost a pity to snatch ♦ hem from their fool's paradise, and reduce them again to the common lot of humanity ; lest they should complain of their cure, like the patient described in Horace,
Pol! me occidistis, amici,
Non scrvastis, ait, cui sic extorta voluptas, Et demptus per vim mentis gratissimus error !
The disposition to insanity, as well as to convulsion, is believed to be hereditary ; and in consequence to be induced in those families from slighter causes than in others. Con- vulsions have been shown to have been most frequently in- duced by pains owing to defect of stimulus, as the shud- dering from cold, and not from pains from excess of stimu- lus, which are generally succeeded by inflammation. But insanities arc on the contrary generally induced by pains from excess or stimulus, as from the too violent actions of our ideas, is in common anger, which is an insanity of short duration ; for insanities generally, though not always, arise from pains of the organs of sense; but convulsions ge- h not always, from pains of the membranes or glands. And it has been previously explained, that though the membranes and glands, as the stomach and skin, receive great
pain
Memoirs of Erasmus Darwin, M.D. 309
pain frorrr want of stimulus ; yet that the organs of sense, as the eye and ear, receive no pain from defect of stimulus.
Hence it follows, that the constitutions most liable to convulsion, are those which most readily become torpid iu some part of the system, that is, which possess less irrita- bility ; and that those most liable to insanity, are such as have excess of sensibility; and lastly, that these two cir- cumstances generally exist in the same constitution-; These observations explain why epilepsy and insanity frequently succeed or reciprocate with each other, and why iuirri tabid habits, as scrophulous ones, are liable to insanity, of which I have known some instances.
In many cases, however, there is no appearance of the dis- position to epilepsy or insanity of the parent being trans- mitted to the progeny. First, where the insanity has arisen from some violent disappointment, and not from intem- perance in the use of spirituous liquors. Secondly, where the parent has acquired the insanity or epilepsy by habits of intoxication after the procreation of his children. Which habits I suppose to be the general cause of the disposition to insanity in this country,
As the disposition to gout, dropsy, epilepsy, and insanity, appears to he produced by the intemperate use of spirituous potation, and is in all of them hereditary; it seems probable, that this disposition gradually increases from generation to generation, in those families which continue for many ge- nerations to be intemperate in this respect ; till at length these diseases are produced ; that is, the irritability of the system gradually is decreased by this powerful stimulus, and the sensibility at the same time increased. This disposition is communicated to the progeny, and becomes still increas- ed, if the same stimulus be continued, and so on by a third and fourth generation ; which accounts for the appearance of epilepsy in the children of some families, where it was never known before to have existed, and could not be ascribed to their own intemperance. A parity of reasoning shows, that a few sober generations may gradually in the same manner restore a due degree of irritability to the family, and decrease the excess of sensibility.
U 3 From
3,0 Memoirs of Eras™ Darunn,M.D.
From hence it would appear probable, that scrophula and dropsy are diseases from inirritability ; but that in epilepsy and insanity an excess of sensibility is added, and the two faulty temperaments are thus conjoined.
Colica flatultnta. — The flatulent colic arises from the too great distention of the bowel bv air, and consequent pain. The cause of this disease is the inactivity or want of suffi- ciently powerful contraction of the coats of the bowel, to carry forwards the gas given up by the fermenting aliment. It is without fever, and generally attended with cold ex- tremities.
It is distinguished, first, from the pain occasioned by the passage of a gall-stone, as that is felt at the pit of the sto- mach, and this nearer the navel. Secondly, it is distin-» guished from the colica saturnina, or colic from lead, as that arising from the torpor of the liver, or of some other viscus, is attended with greater coldness, and with an ach- ing pain; whereas the flatulent colic being owing to disten- tion of the muscles of the bowel, the pain is more acute, and the coldness less. Thirdly, it is distinguished from in- flammation of the bowels, or ileus, as perpetual vomiting and fever attend this. Fourthly, it is distinguished from cholera, because that is accompanied with both vomiting and diarrhoea. And lastly, from the colica epileptica, or hysteric colic, as that is liable to alternate with convulsion, and sometimes with insanity ; and returns by periods.
M.M. Spirit of wine and warm water, one spoonful of each. Opium one grain. Spice. Volatile alcali. Warm fo- mentation externally. Rhubarb.
The discriminations here merit the utmost praise, and are of the highest use to the practitioner.
Colica saturnina. — Colic from lead. The pain is felt about the navel, is rather of an aching than acute kind at first, which increases after meals, and gradually becomes more permanent and more acute. It terminates in paralysis, fre- quently of the muscles of the arm, so that the hand hangs down when the arm is extended horizontally. It is not attended with fever, or increase of heat. The seat of the disease is not well ascertained, it probablv affects some part
of
Memeirs of Erasmus Darwin, M.D. 3U
(I the liver, as a pale blueish countenance and deficiency of bile sometimes attend or succeed it, with consequent ana- sarca; but it seems to be caused immediately by a torpor of the intestine, whether this be a primary or secondary affec- tion, as appears from the constipatiqn of the howels, which attends it ; and is always produced in consequence of the great stimulus of lead previously used either internally for a length of time, or externally on a large surface.
A delicate young girl, daughter of a dairy farmer, who kept his milk in leaden cisterns, used to wipe oft' the cream from the edges of the lead with her finger ; and frequently, as she was fond of cream, licked it from her finger. She was seized with the saturnine colic, and semi-paralytic wrists, and sunk from general debility,
A feeble woman about 40 years of age sprained her ancle, and bruised her leg and thigh ; and applied by ill advice a solution of lead over the whole limb, as a fomentation and poultice for about a fortnight. She was then seized with the colica saturnina, lost the use of her wrists, and gradu- ally sunk under a general debility.
M.M. First opium one or two grains, then a cathartic of senna, jalap, and oil, as soon as th? pain is relieved. Oleum ricini. Alum. Oil of almonds. A blister on the nasrel. Warm bath. The stimulus of the opium, by restoring to the bowel its natural irritability in this case of painful torpor, assists the action of the cathartic.
This disease is generally produced by lead absorbed by the surface — for many practitioners are in the habit of giving sugar of lead, (saccharum Saturni) in spitting of blood, to a considerable extent, as two grains a day, and continued for a fortnight without this disease being produced. The makers of white lead for paint are particularly subject to this disorder, and painters from not keeping the hands clean j and in such case the author of these memoirs has found the highest use in ordering a diet of fat bacon — the corrosive sublimate (hydragyrus muriitus) in a mixture of tincture of bark, an ounce, decoction of bark, six ounces, and two drachms of powdered bark, with two grains of the munated snercury, of which a table spoonful is to be taken night and
U 4 morning
312 Report on a Manuscript Wor\ ofM. Andre . morning — and the bowels are to be first relieved by four grains of calomel, and i.n half an hour a table-spoonful of castor oil, to be repealed every two hours with fomentations. This practice, so successfully employed, of mercury, as a spe- cific in this disease^ appears to be unknown by Dr. Darwin.
[To be continued.]
LVI. Report on a Manuscript Work of M. Andre, for- merly known under the Name of P. Chrysologue de Gy, entitled A Theory of the actual Surface of the Earth. By MM. Hauy, Levierre, and Cuvier. Read to the Class of Mathematical and Physical Sciences in the Na- tional Institute, 1807. «
[Continued from p. 173.}
About the commencement of the 18th century, it began to be considered, that one single inundation, however vio- lent it might be, could not produce such immense effects, of which every day developed more and more their extent.
It was then necessary to admit of a long series of opera- tions either slow or sudden ; and those geologists who stili maintained the real existence of a deluge, considered it simply as the last of the revolutions which have contributed to bring the globe into the state we now see it.
This step once taken, hypotheses were no longer li- mited. In this branch of natural history the systematical method of Descartes was again revived, although Newton appeared to have banished it for ever from the physical sci- ences. Every one conceived a principle a priori, or founded solely on a very small number of partial observations, and employed his skill to accommodate, well or ill, the facts within his knowledge. But, by a fatality hardly con*- ceivable, in the midst of all those efforts, it was almost en- tirely neglected to extend our knowledge of facts ; and when it is remembered that Leibnitz arid BufTon were among the philosophers of whom we speak", it will be allowed that it was neither for want of genius nor talents, that so erroneous a method was adopted.
It is thus that the number of systems of geology is so
augmented.,
Report o?i a Manuscript Work of M. Andre. 313
augmented, that there are at present above 80, and that it is necessary to class them in a certain order, only to aid the memory in retaining their leading principles. Yet the ex- ample of some of the ablest philosophers, during the last thirty years, has contributed so little to prevent additions to this long list, that we every day see some new systems ad- vanced, and our scientific journals filled with reciprocal at- tacks and defences of their authors.
How can so many men of talents, replete with science and integrity, be so discordant, and continue such controversies ! The reason is very simple ; it is, that if one of them were right, neither he nor the others could ascertain it. To dis- cover if a fact is owing to a certain cause, it is necessarv to know the nature of the cause and the circumstances of the fact. What, therefore, in the actual state of the sciences, are the authors of geological systems, but persons who seek the causes of facts, before the facts themselves are known? Can we imagine an end more chimerical ? Yes : we are ig- norant, we do not say merely of the nature and disposition of the interior of the globe, but even of its most exterior crust.
The researches of miners, such as Pallas, Saussure, De- luc, Dolomieu, and the school of Werner, have furnished us with some important general observations, although not yet incontestable, on the primitive mountains : but the se- condary ones, which constitute the most embarrassing part of the problem, are scarcely touched ; and the principal points, on which necessarily depends what relates to causes, are yet in question. We could cite a multitude of examples; but to be brief, we shall confine ourselves to one or two.
Have organised beings lived in the places where their re- mains are found, or have they been transported there ? Do these beings still live, or have they been wholly or partly destroyed?
Is it not evident that the system of supposed causes must ditTer as much as black and white, according as these ques-. tions are answered in the affirmative or negative? Never- theless, no person can yet answer them positively ; and what is still more singular^ no philosopher, I believe, has ever sus- 1 pected
314 Report on a Manuscript Work of M. Andri.
pected that it would be necessary to be able to answer them before attempting to make a system.
Hence the reason why some will have millions of years for the formation of secondary mountains, while others pretend that about 5000 years ago they were formed in one? All the intermediate parts between these two extremes have had their defenders.
There already exist ten or twelve hypotheses for the par- tial explanation of the formation or' the basin of Paris, yet not one of those who have formed them knows what exists in one small corner of this basin, which contains only a few square toises. At Grignon there are 600 species of unknown shells, besides 40 or 50 that are supposed to be known. This fact is stated by M. de Lamarpk, after several years re- searches. Neither does one of them know that our gypsum contains the bones of 12 or 15 quadrupeds, which neither resemble those seen here or elsewhere ; another fact which has only been ascertained after ten years labour.
Judge then what ought to be the explanations coolly ima- gined in the closet by persons to whom these two little circumstances of the phaenomenon were unknown. How then ought a learned society to act, in order to extend and improve so interesting and useful a science, and direct it to real and attainable objects ? It ought in this, as in every other science, to encourage by its approbation all those who state positive facts, and preserve the most rigid silence on the systyems which succeed them. In this manner the au- thors of systems treat the observers or collectors of facts. It is curious to see them all, the moment any discoveries are made by observers, ready to seize them, arrange them ac- cording to their own ideas, and convert them into weapons against their adversaries. It appears as if anatomists, zo- ologists, and mineralogists, were but workmen destined to furnish materials for their fantastical fabrics.
Happily for the example of those who may be tempted to jwrsue such a course, these castles in the air vanish like ap- paritions, and the more solid edifice raised on facts and in- duction begins to appear. The plan, if we may so speak, is already traced; men of judgement at the end of the 18th
century
Report on a Manuscript Work of M. Andre. 315
century have proposed questions; they have already an- swered some, and have indicated the only means by which the remainder may be resolved. The series of problems is proposed, and nothing but enlightened perseverance is wanted to fill up the outline which constitutes the science.
It is not foreign to the object of our report to present here, as an example, some of the principal objects which jappear to us necessary to be profoundly studied, in order to make geology a science of facts, and before attempting, with any hope of success, to answer the grand problem of the causes which have reduced our globe to its actual state. To this end we ought,
1st, To search if the division of great chains in one middle, and two lateral banks or dikes, observed by Pallas, and de- veloped by Deluc, is invariable, and examine, as Ramond has done on the Pyrenees, the causes which sometimes con- ceal them.
2dly, To examine if there is also any thing certain or uni- form in the succession of secondary strata, if such a kind of stone is always below such another, and vice versa.
3dly, To operate in a similar manner on the fossils, de- termine the species which appear the first, and those which are only seen afterwards ; discover if these two sorts never accompany each other, if there are any alternations in their appearance ; that is, if the first found appear a second time, and if the second have then disappeared,
4th, To compare the fossil with the living species more minutely than has hither been done, and determine if there is any relation between the antiquity of the beds, and the similarity or dissimilarity of fossils with the living beings.
5th, To determine if there is any uniform relation of cli- mate between fossils and those living beings which most re- semble them ; as for example, if they have migrated from the north to the south, the east to the west, or ir there have been mixtures and irradiations.
6th, To determine what fossils have lived where they are now found, what others have been transported there, and if there are, in this respect, uniform rules with regard to the Strata, species, or climates.
316 Report on a Manuscript Work of M. Andre.
7th, To follow minutely their different strata throughout their whole extent, whatever may be their doublings, incli- nations, ruptures, and slepings; and also to determine what countries belong to one and the same formation, and what others have been formed separately.
Sth, To follow the horizontal beds and those which are inclined in one or different ways, to determine if there is any relation between the greater or less constancy in their hori- zontal position, antiquity, or nature.
9th, To determine the valleys in which there-entering and saliant angles correspond, and those in which they do not ; also those in which the strata are the same on both sides, and those in which they differ, in order to discover if there is any relation between -these two circumstances, and if each of them taken apart has any analogy with the na- ture and antiquity of the strata composing the heights which limit the valleys.
All these points are necessary to its elucidation, if we wish to make geology a body of doctrine or a real science, independent of every desire which we may have to find an explanation of facts. We dare affirm that there is not one of those points on which any thing absolutely certain is yet known, every thing which has hitherto been advanced being more or less vague. The greatest part of those who have treated of such subjects, have considered them rather as they answer, d their system, than according to impartial observa- tions. ' .
The fossils alone, singly considered, may yet furnish matter for the study of 30 years to several industrious philosophers; and iheir connections wiih their strata will still require as many more years of travel, of boring, and other arduous researches.
What service would not a society such as ours render to- the natural sciences, if it succeeded in directing to these long, laborious, but determinate researches, those persons with an ardent desire of knowledge, who are now likely to be led, by the contagious example of many men of merit, to the adoption of systems so easily created and so flattering to vanitv ! The work of M. Andre, examined according to
these
Report on a Man u script Work 'of M. Andre. $1 7
tlfese principles, presents two distinct parts, only one of which falls within the province of this class. It is that in which this philosopher relates his observations daring his travels.
Faithful to the laws of the religious order to which he belongs, M. Andre has traversed on foot numerous and ex- tensive routes : he travelled as an enlightened observer, noted with care the elevations and cavities of the earth ; the nature of stones, and their relative position to each other and to the horizon. He has taken for a model the geologist who first merited this honour, the celebrated Saussure ; that i3 to say, he lias described in a precise maimer all the objects which struck him on his route, in the order in which they occurred.
A chain of mountains traversed and described with so much care, forms the subject of a general view which M. Andre has not failed to trace. It is thus that he exhibits the part of the Alps which he has seen, and which comprehends the space between St. Gothard and St. Bernard. He after- wards passed to the Jura, a secondary ridjie very different from the Alps, which he examined from the fall of the Rhone to the Rhine, that is, nearly its whole length. The Vosges are the third ridge, a part of which was examined from Epinal to Giromaguy. He describes the bank of se- paration which on the one side throws the water to the ocean, and on the other to the Mediterranean ; he likewise passed from the summit of Salins almost to Cluui ; observed and described a part of the plains which unite the Alps to the Jura, and those which, commencing at the Saone, fol- low the course of the Rhine to Strasburgh.
Although M. Andre, throughout the whole of the first part of his work, frequently alludes to opinions which he endeavours to prove in the second, it is not the less valuable for a great number of interesting facts which he details, and which are independent of all system. Such in the first place are the circi, or circular spaces sunk between high sheltered rocks, which he frequently observed in the Alps. Such, also, are his remarks on certain isolated pyramids, formed of divers layers or strata, the contiguous parts of which must
necessarily
318 Report on a Manuscript Work of M. Andre.
necessarily have been carried off by some cause, although no vestiges of them can now be found at the feet of these py- ramids.
In Vallais, M. Andre describes many steep banks and erosions of the water, which escaped Saussure, who had seen only the lower parr, of the country, and that during no more than two days. Nevertheless he also shows that this great valley, so far from having saliant and re-entering an- gles corresponding on two siJes, enlarges and contracts al- ternately even to live times. In general the article Vallais is one of the most complete in this work, M. Andre having traversed it several times and by different routes. He points out, in several places of the Alps, examples of schistose layers twisted or bent in many directions, which it would be diffi- cult to reconcile with the common theories. In general, however, he appears very little favourable to the idea of the displacing of strata.
His description of Mont Blanc is precise and perspicuous, and will be read with interest even after that of Saussure, to whose veracity and accuracy he renders perfect justice. With the same care he has described St. Goihard and its environs. He remarks that the highest ridges are not in the central chain ; a similar fact occurs in the Vosges. M. Ramond discovered the same thing in the Pyrenees.
In his description of Jura he carefully distinguishes the compact calcareous rock without petrifactions, which forms the central parts of the chain, from the calcareous congre- gation of shells which compose the lateral and less elevated parts. He observed rolied pebbles, and large calcareous stones worn round by moving, like the masses of granite in the Alps ; the latter also were discovered in Jura, although not believed to exist by Saussure, who had not sufficiently examined it, M. Andre likewise speaks of numerous ca- verns and hollows in this chain. He describes its glaciers, particularly the lime glacier five leagues from Besancon. Of this he gives the temperature taken at different periods of the year, to 3how that it is far from being the reverse of the ex- ternal air, as some persons have alleged.
His comparison of the Alps, of Jura, and of Vosges, is
curious ;
Report on a Manuscript Work of M. Andre. 319
curious; in the Alps there are longitudinal and transversal valleys ; in Jura these are almost all longitudinal ; in the Vosges almost all are oblique. We knovy that the Pyrenees have a fourth structure, and that the vaile) s there are very nearly all perpendicular. The Vosges are singular for the quantity of gres and of puddingstone, which cover their isolated summits, and which appear to be the vestiges of an immense platform.
From these details it will appear that M. Andre has care- fully observed the countries over which he has travelled, that the facts which his work contains may be very valuable to positive geology, at least in what relates to the mineral masses; and although he was not particularly occupied with the fossils, we consider that he must take, in this respect, a distinguished rank among observing geologists.
To his own descriptions of the countries which he visited, he has added several extracted from the best authors, such as Saussure, Deluc, Dolomieu, Ramond, and Patrin, on those which he has not seen. Hence the author infers, that there must be a great analogy between distant regions, and that the theories applicable to these countries must be nearly so to the whole earth. At the conclusion he says something of fossils, but solely after other naturalists. Having thus established his data with great care, either from his own observations or from the most respectable authori- ties, M. Andre proceeds to the consequences which he thinks must result from those different facts. After what we have said at the commencement of our report, it will not be expected that we should pronounce judgement on this part of the work ; but we shall not abstain from giving an idea of it.
He thinks that the actual arrangement of the surface of the earth has not existed from a very remote epoch, and he endeavours to prove it, like MM. Deluc and Dolomieu, by the progress of depositions (cboulemens), and by that of de- composition and formation of soil {atterUsemens). ile like- wise thinks that this arrangement is totally owing to a cause unique, general, uniform, violent, and prompt ; and ap- pears to attribute to this cause even the transpur t of foreign 2 fossil#.
&?t) Olservallom ok Sillterraneous Heat.
fossils. He attempts to prove that neither volcanoes, earth- quakes, rivers, nor currents, could possibly arrange the surface of the earth as it is in the present day.
These ideas have also been entertained by several celebrated naturalists, especially when restricted to the last change ex- perienced by the earth. Your committee {coitnnissaires) even feel themselves able personally to adopt them in part, although they well know that the reasons which determine them cannot have the same influence on all the world. Yet, for the reasons which they have before stated, they do not wish to engage the Class to pronounce on such subjects. But they do not hesitate to propose, that the Class should testifv to M. Andre the esteem which it owes to his labo- rious researches, and to the enlightened zeal which induces him to continue his useful labours at so advanced an age. They do not doubt that the work of this respectable philo- sopher will be received by naturalists as a collection so rich in interesting facts ought to be.
LVIT. Observations upon Suh terraneous Heat, made in the Mines of Poullcouen, and of Huelgoat, In Britamj, in France. Bv J. F. Daubui.sson*.
J. here are few questions in physics, respecting which it is more necessary to be in possession of positive and well established facts, than the temperature of the interior of the globe, taken at depths which it is in our power to visit. I have already published some facts on this subject with re- spect to the mines of Saxony, and now proceed to detail some others resulting from observations made last summer (1806) in the mines of Poullaouen, and of Huelgoat, in Britany. The habits to which I have been accustomed of examining these subjects, added to my knowledge' of the countrv, having enabled me to choose, with some discern- ment, the points where I wished to ascertain the tempera- ture, I hope that the facts I am about to relate will not be unintercstmg to those who are occupied with the physics of
* From the 'Journal dc? Mines, vol *x.i. p. l\9.
the
Observations on Subterraneous Heat, 321
the terrestrial globe. The thermometer I used was a mer- curial one, and graduated into twenty-four parts, from the freezing point to that of boiling water. It was inclosed in a glass tube. I ascertained by experiment, that when it In- dicated a certain degree of heat, and when it was removed about twelve degrees therefrom, three or four minutes were requisite if it was dipped in water at the freezing tempera- ture, and eleven or twelve minutes when held in the air. According to these data, at all times when I wished to take the temperature of a mass of water in mines', I plunged the thermometer entirely into it and kept it there five minutes: when a mass of air was to be examined, I helcf the thermo- meter a quarter of an hour. All these observations were re- duced to the centigrade thermometer. However great the care and patience I bestowed, I could never answer pre- cisely within a quarter of a degree.
Observations made at Poullaouen. I shall begin by describing the position of the place. The mine of Poullaouen is situated in 48° 17' 49" of lati- tude, and 5° 55* 57" longitude west from Paris.: its orifice (St. George's pits) is 106 metres above the level of the sea.- Tt is four myriametres from the north extremity of Britany, and six from the south and east extremities. The country in which it is situated forms part of the tongue of land which, in the form of a roof, the ridge of which is 260 metres above the level of the sea, advances into the ocean, and con- stitutes the country called Britany. The district in which the mine is situated is about 150 metres above the level of the sea: this country is broken up in every direction by valleys ; one of them resembles an almost circular basin about a thousand metres in diameter, and it is under the Soil of this basin (which is 106 metres above the level of the sea) that the mine of Poullaouen is wrought.
According to the law followed by the heat of the equator at the pole, the mean temperature of the surface* of the earth at Poullaouen ought to be 12*4°*. The elevation of • I have been led both from theory and observation to use an extremely- simple expression describing thethermometrical temperature of any place, the latitude of which is known. This expression is, 30-7° Coss. a"-5 latitude ; or with a sufficient exactitude in the temperate zone, 28° Coss. 2 latitude.
Vol. 33. No. 132. April 1809. X the
32 2 Observations on Sulterraneous Heat.
the ground requires nearly a degree of diminution ; so that Wt may estimate the mean temperature as 11*5°.
My observations were made on the 5th of September 1806. During the whole of the day the sky was serene and cloud- less. The temperature taken in the shade at mid-day was 19°. In detailing the rest of my observations, I shall lay down the position of the points at which they were made, as well as what appeared to me to influence the temperature. By the side of each thermometrical expression I shall give the depth below the surface of the point to which it refers :
1st, In the first gallery, called the level of 50 feet, near the pit .by which we descend, in a place where there is but a feeble current of air, a little water which was upon the ground indicated, — Temperature 13'1°. Depth l6m.
2d, In the gallery of St. George, under the intersection of three branches of the ridge, in a kind of culdesac, far distant from the place occupied by the miners, where there was no current of air, but from the upper part of it a great quantity of water filtered. This water gave, — Temperature 11-9°. Depth 39n.
3d, The water of filtration which fell into this gallery (Sr. George's) indicated, on being brought to the mouth of the pit, — Temperature 12*1°. Depth 39m.
4th, Thirty-six metres lower down, at the level of la Boullaye, towards the extremity of a long gallery, where there is neither a current of air nor a single workman ; in the water I found, — Temperature 11*9°. Depth J5m.
5th, At the very bottom of St. George's pit, in the hole wherein the waters collect which have fallen from above; the water indicated, — Temperature 14-2°. Depth 142m.
6th, The air above this water, — Temperature 15°. Depth 141m.
7th, In the hole at the bottom of the pit St. Barbe, (at the other extremity of the mine,) in the water I found, — Temperature 13*5°. Depth 150m.
8th, In the air above this- water, — Temperature 14*4°. Depth ,150m.
9th, The water of the old excavations adjoining,. — Tern- - perature 13*3°.
KB.
Observations on Subterraneous Heat. 323
K".B. The waters coming from the flltrations (which prin- cipally take place in the upper parts of the ancient works) are cold ; and as they form the greater part of those which flow into the pit or well of St. Barbe, they are thevcause of the little heat presented by those which exist there.
10th, In an excavation not far distant from the bottom of the well of St. Barbe (called the furnace gallery), the sides of which are almost completely covered with radiated py- rites, partly efflorescent, the thermometer left for more than a quarter of an hour in a small hollow made in the midst of the pyrites, and which contain a good deal of white sulphate, — in this case the thermometer stood at, — Tempe- rature 14-6°. Depth 140m.
1 lth, When afterwards plunged into a small hole whence a very strong spring issued, it also stood at, — Temperature 14-6°. Depth. 1 JOm.
Consequences. — 1st, Observations 2, 3, and 4, prove in- contestably that the heat of the rock in the upper parts of the mine is 12°, as the waters which indicated it filtered through the rock ; and we find that this temperature does not sen- sibly differ from that- pointed out by theory. If the first Ob- servation gave a greater heat, it is because it was made in a place through which air from without continually passes ; and this air was warm, the experiments having been made at the end of summer.
2d, Observations 5 and 6 also show that the temperature of the lower parts of the mine is more considerable than that of the upper parts. If in deep places the air appears to be warmer than the water, it is probably because it has preserved a part of the heat which it had upon entering the mine. I have already assigned the reason which accounts for our having in Observations 7, 8, 9, av less heat than might be expected from the depth.
3d, Experiments 10 and 11 show that there are cases in which the presence of pyrites does not produce heat : the heat indicated in these cases cannot depend upon that cause : in the pit of St. George there is no pyrites, and the tempera- ture is the same.
Thus, if we abstract every extraordinary cause, the Ob- X 2 servations
324 Observations on Subterraneous Heat,
Nervations I have related appear to me to indicate that, at the depth of 1 50 metres, the temperature is at Pouallouett 3° or 4 higher than at the surface of the ground.
Observations made at Hnelgoat.
The mine of Huelgoat is situated at 48° 1&' 17" latitude, and 6° l' 4(3" of west longitude: i»$ orifice (the mouth of the pit) is 173 metres above the level of the sea. It is situ- ated upon a broad hill, which separates two valleys, the depth of which is from 80 to 90 metres.
From what we have said as to the latitude and elevation, we may conclude that the mean temperature is 11°.
The rock like that at Poullaouen is an argillaceous schist, and also contains several strata of aluminous schist.
The following are the Observations made by me on the 5th of September, being on the same day with those made at Poullaouen.
1 st, In a gallery about five metres below the one by which the workmen generally enter the mine, which has no other orifice but one, and which no person has entered for many years, where there is no current of air, the thermometer placed at its northern extremity marked in about 20 mi- nutes,—-Temperature 11°*
After having descended the pit called the Miners' pit, I entered another pit which adjoined a gallery absolutely with- out any communication with the rest of the mine, and in which there was consequently no current of air.
2d, The thermometer, when plunged into a little stag- nant water upon the ground, rose to, — Temperature 12*2°. Depth 70m.
3d, I reascended to the first gallery, and in the water of a gutter, in a place through which a current of air passed, the thermometer marked, — Temperature 13*7°- Depth 6om.
t then proceeded southward, to the spot where they were then working.
4tl\ In the second gallery, a little way from the pit by which the produce of the mines is extracted, in a place where there was a continual and strong current of air, a little stag- nant water marked, — Temperature 1 5\ Depth 80m.
5th,
Observations on Sul terraneous Heat. 325
5th, In the fifth gallery, the thermometer, plunged into a water-tank near the great pit, rose to, — Temperature 17J. Depth 160™.
6th, At the extremity of the gallery No. 9-f> a great quan- tity of water is seen to issue from the roek slightly vitriolic : the thermometer, when held a quarter of an hour in the midst of the jet, constantly marked, — Temperature 19'7°* Depth 230m.
7th, When held in the air on one side, it also marked, — Temperature 19*7°. Depth 230m.
8th, About 60 paces nearer the mouth of the pits, the water of the stream formed from the above jet stood also at, — Temperature 19-7°. Depth 230*.
The bottom of the mine was under water which was 16 metres deep. I descended through a small pit, a short way from the great one, to the level of the subterraneous lake.
9th, The thermometer, when kept for a quarter of an hour upon a plank floating in the water, marked, — Tem- perature 18*8°. Depth 238m.
10th, When plunged in water it also indicated, — Tem- perature 18*8°. Depth 238m.
All the water which flowed into this southern part of the mine proceeded to the subterraneous lake from which it was pumped up.
11th, The temperatuft? of the water poured into the gal- lery No. 7, from the pump, was, — Temperature 19*4°. Depth 180m.
Proceeding along this gallery the water flowed into another pit in the northern part of the mine.
12th, Here it mingled with a small quantity of water, the temperature of which was i^°. Depth J20m.
13th, And when the whole together were poured, by means of pumps, into the uppermost gallery, they marked, — Tem- perature 18*4°.
We have here two classes of observations, which must be kept distinct ; namely, those made in the northern, and in the southern part of the mine.
The former, in my opinion, indicate the natural tempera- ture of the soil. No. 1, being made 20 ^L^O metres below
X 3 the
326 Observations on Subterraneous Heat,
the surface of the ground, ought to be regarded as giving the real degree of heat of the surface of the country in general. I see no cause which could alter the temperature naturally proper for this place, which is far distant from any working places : one thing is certain, that it continues the same during the whole year ; and the result is precisely the same as pointed out by theory. Observations 2 and 3 also show that this temperature increases in proportion as wc descend. The current of air in the first gallery account^ for the trifling excess of heat we remark there in propor- tion to the depth.
As to the temperature of the Observations made in the southern part of the mine, it is visibly influenced by an ex- traneous cause ; namely, by the vitriolic water which flows from the south. On digging a new pit 100 metres distant from the south part of the present workings, they have cut through beds of an aluminous schistus, which has a very strong styptic taste. By the help of a microscope we dis- cover in it a multitude of pyritous points, which, by their decomposition and their action upon the schistus, have probably produced a disengagement of caloric, which must have heated the water passing through these beds. The latternot being very deep, communicate with the atmosphere by some fissures, while decompositions and disengagements must have been effectuated in the interior of the earth.
However this may be, it seems certain that it is by pass- ing through these beds that the water must have acquired a heat of 20°, a heat far superior to that which agrees with the depth at which it is found.
I shall also here observe, that if we ascribe this .heat to the pyrites, they produce it by their action upon the schis- tus. In the observations made at Poullaouen, we have seen pyrites in a considerable quantity occasion no particular in- crease of heat. I shall repeat here what I have said in an- other place : I have seen workings of pyrites, and I have not found the heat sensibly stronger than in other mines: thus I am led to think that the pyrites in a mass, at beaut those not radiated, produce no subterraneous heat: but those which are disseminated in minute particles in a body upon
which
Method to ascertain the Value of Growing Timber Trees, 327
which the sulphuric acid can have an action, act different- ly when there is an accession of atmospheric air. I have remarked in another Memoir, that it is not the coal which contains most pyrites, which gives in the inside of the mines the inflammable gas known by the name of fire- damp, but rather the coal which contains little or none visible to the naked eye, and in which the sulphuret of iron probably exists in particles not discernible.
LVIir. Method of ascertaining the Value of Growing Timber Trees, at different and distant Periods of Time. By Mr, Charles Waistell, of High Holborn*.
nSIR>
V^onceiving that the Tables contained in the annexed papers will afford useful information to growers of timber, and tend to encourage the growth of it in these kingdoms, and thereby promote the views of the Society of Arts, &c. I trust you wilfhave the goodness to lay them before the Society, as I have formed them with great attention.
Having last autumn viewed some plantations made under my direction about thirty years ago, I found the value of one of them much to exceed my expectation. I became there- fore desirous to devise some means of estimating what its value might probably be at different future periods. I was thus led to construct the first of these tables, and on the completion of this, other tables seemed necessary; and T was thus progressively led on to the construction of the whole. For this purpose I searched in various authors for the mea- sure of trees, in girt and height, at different ages, and ob- tained similar information among my acquaintance. Hence I collected, thai the increase in the circumference of trees is generally from about one to two inches annually, and from twelve to eighteen inches the annual increase in height. Some fall a little short, and some exceed those measures.
* From Transactions of the Society for the Encouragement of Arts, Manufac- tures, and Commerce, for 1808. The gold medal of the Society was voted
to Mr. Waistell for this communication.
. X4 I shall
328 Method of ascertaining the Value
I shall now briefly notice a few of the advantages to be derived from the first Table.
1st, Jhe first Table shows every fourth year, from twelve years old to a hundred, the rates per cent, per annum at which all trees increase, whether they grow fast or slow, provided their rate of growth does not vary. This table may- be the means of saving young thriving woods from being cut down, by showing how great a loss is, sustained by fell- ing timber prematurely *.
2d, And it may be the means of bringing old trees to market, by showing the smallness of the interest they pay for the money they are worth, after they are 80. or 100 years old.
But this table shows the interest which they pay, only, whilst the trees continue growing at their usual rate. In, case they fall short only a little of their usual increase in jlirt, this considerably diminishes the rate per cent, per an- num of their increase. And trees do decrease in their rate of growth before they ^appear to do so f. A pale and mossy bark are certain indications of it.
3d, The first Table may also assist the valuer of such timber as is not to be cut down, but to continue growing, by enabling him to estimate its present value more accurately
* " A wood, near West Ward, in Cumberland, of more than 200 acres, was felling in 1794, it was little more than SO years Qld. The whole was cut away without leaving any to stand." See Miller's Gardener's Dictionary, last edition^ under the Head of Woods.
At 30 years old timber pays 10 per cent, for standing, and probably this wood might have paid 7 per cent, per annum on an average for the next 80 years.
f In Mr. Pringle's Agricultural Report cf Westmoreland h a paper of tfce Bishop of Landaff's, stating, "That a very fine oak, of 82 years growth, measured in circumference at six feet from the ground, on the 27th of Gc-? tober 1792, 107 inches, and on the same day of the same month in 1793, it measured 108 inches." He then states the interest it paid to be only about 2 per cent., and says this tree was a singularly thriving one. It is evident that, with all this appearance of thriving, it was on the decline. For if we divide 108, its inches in circumference, by 82, its age, we find its average annual increase had been one inch and a third. Its falling off to one inch re- duced the rate per cent, of increase one-fourth.
tha&
of Growing Timler Trees, 329
Chan is usually done, especially when it is increasing after a high rate per cent, per annum*.
The second Table shows the rate per cent, to be the same as in the first Table, though the annual increase is more both in height and circumference.
The third Table is calculated to show the number of trees that will stand on an acre of ground, at the distance of one- fifth of their height, (which distance is recommended by Mr. Salmon, in a paper in the Society's 24th volume,) and the number of feet the trees will contain, both those to be cut out, and those to be left standing, at the end of every four years, from 16 to 64 years old, supposingthey increase 12 inches in height and 1 in circumference annually. This distance may suit fir trees, but will be too near for oaks.
The fourth and fifth Tables show the same particulars when the trees grow at greater rates.
The sixth Table is calculated to show the same particulars when the trees are constantly thinned out, every four years, _ so as to leave them at the distance of one-fourth of their height. According to this table there will be 48 trees left on an acre when they are 120 years old; and it seems ge- nerally agreed, that from 40 to 50 full-grown oak trees are as many as have sufficient room to sand on an acre.
The. seventh Table shows the same particulars respecting trees which increase 15 inches in height and l| inch in cir- cumference annually.
The eighth Table shows the same particulars respecting trees which increase 18 inches in* height, and two inches in circumference annually.
The ninth Table shows the same particulars as Table 6, till the trees are 28 feet high, after which the distance is in- creased from one-fourth to one-third of their height.
The 10th, 11th, and 12th Tables show the annual in- crease in boles of ?4, 32, and 40 feet long, and the differ- ence of their increase at the same ages.
* A fir wood of more than SO acres, and about 30 years old, was latelv valued to be sold with an estate, by several eminent wood-valuers, without taking into consideration its rate of increase. It was then increasing' after the rate of 10 per cent, per annum, and probably would increase after the rate of 8 per cent, on an average for the next 20 vear*.
To
330 Method of ascertaining the Value
To these Tables succeed comparative statements, showing
the number of feet contained in boles of* different lengths,
when the trees are 60 years old ; by which it appears, that,
if cut down at that age, the longest boles are not the most
profitable to the growers of timber. And I have added the valuation of the plantations before
alluded to, with remarks on them. *
Having finished my introductory remarks, I conclude,
and am, Sir, your very humble servant,
Charles Waistell.
Tables respecting the Growth of Timber. Calculations, showing every fourth year, from 12 to 100,
the progressive annual increase in the growth of trees, and
gradual decrease in the rate percent, per annum, that the
annual increase bears to the whole tree.
The whole .height of the trees is taken to the top of the leading shoot, and the girt in the middle ; but no account is taken of the lateral branches.
If trees increase 12 inches in height and 1 in circumference annually, their increase will be as undermentioned, viz.
TABLE T.
|
Girt |
Contents. |
"3 b" |
Girt. |
Contents. |
One year's |
Rate per |
||||
|
§^ |
3^ |
increase. |
cent, of |
|||||||
|
-"* |
> * |
increase. |
||||||||
|
inch |
ft. |
in. |
pts |
inch |
ft |
in pt. ids |
ft. in. pt. sds |
|||
|
12 |
H |
0 |
2 |
3 |
13 |
if |
0 |
2 10 3 |
0 0 7 3 |
26-8 |
|
16 |
2 |
0 |
5 |
4 |
(7 |
2J |
0 |
6 4 9 |
0 10 9 |
19-9 |
|
20 |
ft |
0 |
10 |
5 |
21 |
** |
1 |
0 0 8 |
0 17 8 |
15-7 |
|
24 |
3 |
1 |
6 |
0 |
25 |
*i |
1 |
8 4 1 |
0 2 4 1 |
IS- |
|
28 |
3* |
2 |
4 |
7 |
29 |
3* |
2 |
7 9 1 |
0 3 2 0 |
IV |
|
32 |
4 |
3 |
6 |
8 |
33 |
4| |
3 |
10 9 6 |
0 4 16 |
967 |
|
r>6 |
<H |
5 |
0 |
9 |
37 |
4* |
5 |
5 11 5 |
0 5 2 5 |
8-5 |
|
40 |
5 |
G |
1] |
4 |
41 |
5£ |
7 |
5 8 10 |
0 6 4 10 |
7-6 |
|
44 |
H |
9 |
8 |
11 |
45 |
5f |
9 |
10 7 9 |
0 7 8 9 |
6-96 |
|
48 |
6 |
12 |
0 |
0 |
49 |
H |
12 |
9 2 3 |
0 9 2 3 |
6-38 |
|
52 |
6i |
1.5 |
a |
0 |
53 |
6* |
16 |
1 10 2 |
0 10 10 2 |
5-9 |
|
56 |
7 |
19 |
0 |
8 |
57 |
n |
20 |
1 1 7 |
10 5 7 |
5-4 |
|
60 |
7' |
23 |
5 |
2 |
61 |
7j |
24 |
7 6 6 |
12 4 6 |
5-1 |
|
a |
8 |
28 |
1 |
4 |
65 |
8* |
29 |
9 7 0 |
14 3 0 |
4-76 |
|
68 |
8} |
34 |
l |
4 |
69 |
*i |
35 |
7 8 11 |
1 6 4 U |
4-49 |
|
72 |
9 |
40 |
6 |
0 |
73 |
H |
42 |
2 6 4 |
18 6 4 |
4-2 |
|
76 |
9'i |
47 |
7 |
6 |
77 |
H |
49 |
6 5 2 |
1 10 11 2 |
3-98 |
|
80 |
10 |
55 |
6 |
8 |
81 |
104 |
rn |
7 11 9 |
2 1 3 9 |
3-79 |
|
84 |
101 |
64 |
9 |
8 |
85 |
10* |
66 |
7 7 8 |
2 3 11 8 |
3 6 |
|
88 |
11 |
7a |
10 |
4 |
89 |
US |
76 |
5 11 1 |
2 7 7 1 |
3-5 |
|
92 |
w |
84 |
5 |
'9 |
93 |
Hi |
87 |
3 4 0 |
2 9 7 0 |
3 3 |
|
96 |
12 |
06 |
b |
0 |
97 |
99 |
0 4 6 |
3 0 4 6 |
315 |
|
|
i'oo |
11" |
108 |
$ |
0 |
101 |
ISf ! |
111 |
9 '6 8 |
3 3 • 6 8 |
3- |
III
of Growing Timber Trees. 331
In Table X. of the increase of a bole of 24 feet in height, of a tree growing at the above-mentioned rate, it will be observed, that the contents at 24 years of age arc the same, and at 64 years nearly the same as in the above Table, but the contents of the bole at all the intermediate periods ex- ceed the above. And a 40 feet bole exceeds the above con- tents from 44 years to 100, as may be seen in TaDie XIL For these reasons chiefly I did not think it necessary to take into consideration the decrease in height that takes place irt trees at different ages, according to the kind of tree and quality of the soil.
The increase per cent, per annum is the same as the above in all trees at the same age, whether they have grown faster or slower, provided their increase in height and thickness annually has not varied on an average. The progress of trees is sometimes greatly retarded by insects destroying their leaves, by unfavourable seasons, and by their roots penetrating into noxious strata. But these accidents cannot enter into calculations.
Calculations, showing every fourth year from 12 to 64, the progressive annual increase in the growth of trees, and the gradual decrease in the rate per cent, per annum that the annual increase bears to the whole tree. The whole height of the trees is taken to the top of the leading shoot, and the girt in the middle ; but no account is taken of the lateral branches.
If trees increase eighteen inches in height, and two inches in circumference, annually, their increase will be as under- mentioned, viz.
TABLE II.
|
O * |
•J , |
3 J |
_£ |
R$te per- |
|||||||
|
"to L: '3 La |
Contents. |
C |
Contents. |
One year's |
cent, of |
||||||
|
X p |
<h |
S |
3 |
increase. |
increase. |
||||||
|
feet. |
in. |
ft. in.pt. |
feet |
inch. |
ft. |
in. pt.sd |
ft. |
in. pt.sd. |
|||
|
12 |
18 |
3 |
1 1 6 |
13 |
19* |
34 |
1 |
5 1 0 |
0 |
3 7 0 |
26-5 |
|
16 |
84 |
4 |
2 8 0 |
17 |
25 A |
H |
9 |
2 4 0 |
0 |
B 4 0 |
19-8 |
|
20 |
30 |
s |
5 2 6 |
8J |
si |
6 |
0 3 6 |
0 |
9 9 6 |
156 |
|
|
24 |
36 |
6 |
9 0 0 |
25 |
H |
10 |
2 0 6 |
1 |
2 0 6 |
IS* |
|
|
28 |
42 |
7 |
14 3 6 |
29 |
43j |
n |
15 |
10 6 0 |
1 |
7 0 0 |
11- |
|
32 |
•IS |
6 |
21 4 0 |
49$ |
H |
23 |
4 8 0 |
8 |
0 8 0 |
96 |
|
|
36 |
54 |
•:> |
30 4 6 |
H |
32 |
11 7 6 |
2 |
7 1 6 |
8-5 |
||
|
40 |
60 |
to |
41 8 0 |
41 |
61J |
10* |
44 |
10 3 6 |
9 |
2 3 6 |
7 $ |
|
44 |
66 |
11 |
55 5 6 |
45 |
67* |
Hi |
59 |
3 10 0 |
3 |
10 4 0 |
6-9 |
|
48 |
72 |
IS |
72 0 0 |
49 |
734 |
m |
76 |
7 1 0 |
4 |
7 10 |
6 3 |
|
52 |
78 |
13 |
91 6 6 |
53 |
79| |
iw |
96 |
10 11 6 |
5 |
4 5 6 |
5-8 |
|
56 |
84 |
14 |
114 4 0 |
57 |
85£ |
14* |
120 |
6 8 6 |
6 |
2 8 6 |
' 54 |
|
60 |
90 |
!.. |
140 7 6 |
61 |
9ii |
.15? |
147 |
9 2 0 |
7 |
1 8 0 |
5- |
|
64 T |
96 |
16 |
170 8 0 |
65 |
97A |
16* |
178 |
9 4 0 |
8 |
1 4 0 |
4-7 |
Explanation
Royal Society.
Explanation of the Construction of Tables T. and If.
To render the preceding tables easv to be understood by persons not . ;d fo calculations, I will state the" pro-
cess (if the operation* in the firswline of Table II.
The height of the tree at 12 years of age is supposed to be IS feet to the top of its leading shoot, aud £4 inches hv. circumference at the ground consequently, at half the height, the circumference is 12 inches,— - one-fourth' of this, being three inches, is called the girt. The girt being squared and multiplied into the height, gives one foot one inch and six parts for its contents. At J 3. years old the tree will be ig\ feet high, 26 inches in circumference at the grcund3 and 13 inches at half the height ; .one-fourth of 13 gives 3| inches for the girt. This squared and multiplied into the height, gives one foot five inches and one part for the contents. Deduct from this the contents of the tree at 12 years of age, and there remains three inches and seven parts, which isjhe increase in the 13th year. Then reduce the contents of the tree when 12 years old, and the increase in the 13th year, each into parts, dividing the former by the latter, and the quotient will be 3*76; by this number divide 100, and the quotient is 26-5, which is the rate per cent, of increase made hi the thirteenth year; consequently whatever the tree might be worth when 12 years old,' it will, at the end of the 13th year, be improved in value after the rate of 26/. 105. per cent., or in other words, that will be the interest it will- have paid that year for the money the tree was worth the preceding year.
At every succeeding period, both in this Table and Table I., the like process is gone through.
[To be continued.]
LIX. Proceedings of Learned Societies.
ROYAL SOCIJiTV. XML*
April 13. — Earl of Morton in the chair. A paper by the Rev. Mr. M° Gregor, on native arseniate of copper, was Tead. The existence of this substance in nature has long been hejd problematical, and its discovery in amine between
50 and
Royal Society.— Society of Antiquaries, x ' 333
50 and 60 fathoms below the surface of the earth, in Corn- wall, is an additional stimulus to pursue our researches. This mineral is of a pale yellow colour ; two specimens of it were analysed by Mr. Mc Gregor, one of which contained 69. —of arsenic acid, and 2(3. — copper; the other 72. — acid, and 28. — copper. Some muriate of iron and silica were also found, but they are deemed not essential to the mineral.
April 20. — The President in the chair. Dr. Chisholm laid before the Society some particulars respecting, a raceof pygmies, said to exist as a nation in the centre of the island of Madagascar; A M. Baudin, who had visited that island and spent 50 days among them, and who was in the French West Indies, had one of these beings preserved ; it w as a man about 33 years of age, measuring only 32 inches, but perfectly proportionate in all his parts. A child of a year old was also preserved in spirits, and measured one foot. These people are represented as beiug much fairer than the other natives, and of a bright copper colour ; they are also said to be very ingenious, to be expert with bows and ar- rows, or javelins; and to be hospitable, humane, and gene- rous. One account states them to have long hair, and an- other short and woolly. They are also very numerous, M. Baudin having seen above 8000 in one town. The wo- men are said to have little breasts and almost no milk, so that the children are fed with that of cows. Dr. Chisholm, who personally inspected and measured these preserved bo- dies, concludes, that a pygmy race should no lunger be con- sidered as fabulous, and that such has now been discovered in Madagascar. Some other French voyagers have likewise mentioned the existence of these singular people.
SOCIETY OF ANTIQUARIES.
Monday, April 24, (St. George's day falling on a Sunday,) the Society of Antiquaries met at their apartments in So- merset-place, in pursuance of their statutes and charter Of incorporation, to elect a president, council, and officers of the Society for the ensuing year : whereupon — . The Most Noble George Marquis of Townshend and Earl •f Leicester; F. A. Barnard, Esq.; W. Bray, Esq.; Nich.
Carlisle,
354 Society of Antiquaries. — Intelligence*
Carlisle, Esq. ; F. Douce, Esq. ; Sir IT. C. Engle field, Bart. $ A. Hamilton, D.D. ; S. Lysons, Esq.; C. Ord, Esq. 5 M. Raper, E*q. ; J. Windham, Esq., (eleven of the Coun- cil,) were rcchosen of the New Council ; and —
George Earl of Aberdeen; J. Caley, Esq.; W. Hamil- ton, Jim. Esq. ; A.B. Lambert, Esq.; Charles Lord Bishop of Oxford: R.Pearson, M.D. ; T. B. Richards, Esq.; Sir I.T.Stanley, Bart. ; J. Symmons, Esq. ; H. N.Willis, Esq., (ten of the other members of the Society,) w^re chosen of the New Council : and they were severally declared to be the Council for the year ensuing. And on a report made to the officers of the Society, it appeared, that —
The Most Noble George Marquis of Townshend and Earl of Leicester was elected President; William Bray, Esq., Treasurer; William Hamilton, Jim. Esq., Director; Rev. Thomas William Wrighte, A.M., Secretary; and Nicholas Carlisle, Esq., Secretary for the year ensuing.
The Society afterwards dined together at the Crown and Anchor Tavern in the Strand, according to annual custom.
LX. Intelligence and Miscellaneous Articles.
\Js the 25th of March as Mr. John Barnes, a Gravesend pilot, was proceeding in his boat to the Nore, he observed the sea unusually agitated a few miles below Gravesend, and approaching the spot, he perceived a whale struggling in the water: he immediately fired a swivel three different times; the second shot struck it in the tail, and the third wounded it mortally in the body, when, by a violent and sudden plunge, it threw itself on the beach, and was left nearly dry at low water. Four hours elapsed from the time it was wounded until it was perfectly dead, and it was towed next tide to Gravesend, where it was exhibited during four days. It was then brought up the Thames above London Bridge in a large barge, into which it had been previously put by the barge being scuttled and sunk, and afterwards floated to the surface, the whale having been first towed over it at high water, so that on the ebb of the tide it was left m the barsje.
The
Intelligence. — Lectures* 335
The scuttles were then plugged up, and the barge floated on the return of the tide.
This is the only animal of the kind seen in the Thames since the year 1780, when a whale 90 feet in length was killed near the same place.
Many seamen who have been in Greenland, after examin- ing the whale in question, pronounced it to be a young one not exceeding a year old ; yet its dimensions were as follow : -
Extreme length from the lower jaw to the end of the tail 76 feet six inches ; from the lower jaw to the end of the body at the tail 69 feet ; lower javv longer than the upper jaw 1 foot 4 inches; end of upper jaw to its eye 14 feet ; from the upper jaw to its dorsal fin 48 feet 2 inches ; length of dorsal fin at the base 4 feet; height of the dorsal fin 2 feet; from the body to the end of the tail 7 feet 6 inches; extre- mity of the tail 15 feet; circumference of the body at the dorsal fin 21 feet; eye placed from the spiracle 5 feet; length of the mouth from the jaw 16 feet 6 inches ; length of pec- toral fin 6 feet, breadth of ditto 2 feet; longitudinal lines (almost straight) beginning under the mouth to the middle of the fish ; length of its eye 5 inches; colour of its lamina? whitish towards the back behind ; distance of the eye to the mouth 5 inches; 61 feet to the pectoral fin from back bone; outer skin peeled off, thickness of fine writing-paper ; from one eye to the other 9 feet 9 inches ; breadth of the lines on the belly 3 inches ; orifice of its ear 3 inches ; from its eve to its ear 3 feet 2 inches. It is pronounced by naturalists to be the Balena hoops, or pike-headed species.
After being exhibited for about eight days to the inhabi- tants of London, it was put up to public sale and produced seventy-five pounds.
LECTURES.
Dr. Clutterbuck will commence his Summer Course of Lectures on the Theory and Practice of Physic, Materia Medica, and Chemistry, on Monday the 5th of June, at Nine o'Clock in the Morning, at his House, No. 1, Cres- cent, New Bridge Street, Blackfriars ; where further parti- culars may be had.
METEORO-
»3G Meteorology.
meteorological table,
By Mr. Carey, of the Strand>
For April 1809.
|
' |
Th( |
jrmom |
eter. |
Height of the Barotto. inches. |
ecacesofDry- essby Leslie's [ygrometer. |
* |
|
D vys of the Mouth. |
^2 w> °*S P O |
§ * |
u . o *-> Sf/, |
Weather* |
||
|
OO |
Q c^ |
|||||
|
March 27 |
37° |
55° |
43° |
29*32 |
52 |
Cloudy |
|
28 |
43 |
49 |
42 |
•50 |
0 |
Rain |
|
29 |
42 |
45 |
40 |
•76 |
30 |
Cloudy |
|
30 |
37 |
44 |
41 |
•79 |
34 |
Cloudy |
|
31 |
43 |
45 |
39 |
•72 |
30 |
Cloudy |
|
April 1 |
37 |
44 |
35 |
•76 |
51 |
Cloudy |
|
o |
36 |
44 |
32 |
•80 |
52 |
Shower of sleet |
|
3 |
33 |
43 |
32 |
•86 ' |
5 4 |
Ditto ditto |
|
4 |
31 |
40 |
30 |
30-05. |
30 |
Ditto ditto |
|
5 |
30 |
42 |
32 |
•25 |
41 |
Ditto ditto |
|
6 |
33 |
46 |
40 |
•14 |
38 |
Cloudy |
|
7 |
40 |
46 |
39 |
•20 |
34 |
Cloudy |
|
8 |
39 |
51 |
43 |
•so |
48 |
Fair |
|
9 |
43 |
53 |
44 |
•03 |
35 |
Cloudy |
|
10 |
44 |
56 |
47 |
29*72 |
51 |
Cloudy |
|
11 |
47 |
47 |
35 |
•38 |
25 |
Showery |
|
12 |
36 |
49 |
42 |
•75 |
27 |
Fair |
|
' , 13 |
43 |
52 |
40 |
•21 |
37 |
Showery |
|
14 |
42 |
49 |
40 |
,*09 |
0 |
Thunder with hail |
|
15 |
40 |
4 9 |
42 |
'56 |
41 |
Cloudy |
|
16 |
48 |
54: |
41 |
•06 |
47 |
Showery |
|
17 |
40 |
41 |
33 |
•22 |
0 |
Rain |
|
18 |
33 |
43 |
32 |
•60 |
31 |
Storms of sleet |
|
19 |
32 |
45 |
38 |
•72 |
51 |
Fair |
|
20 |
33 |
44 |
33 |
'66 |
36 |
Storms of sleet a great fall of snow during the night. |
|
21 |
33 |
47 |
45 |
•55 |
30 |
Cloudy |
|
22 |
44 |
47 |
43 |
•70 |
28 |
Cloudv |
|
23 |
43 |
46 |
42 |
30-05 |
21 |
Cloudy |
|
24 |
40 |
47 |
39 |
•30 |
25 |
Cloudy |
|
25 |
39 |
47 |
46 |
• -25 |
26 |
Cloudy |
|
26 |
46 |
49 |
46 |
29*82 |
0 |
Rain |
N. B. The Barometer's height is taken atone o'clock.
C 337 J
French Institute. LXI. Report on the ponderous Flint Glass intended for the Manufacture of Achromatic Glasses. Presented to the In- stitute by M. DouEourgerais, Optician to His Majesty the Emperor and King.—Laid before the Class of Mathe- matical and Physical Sciences, by Messrs, De Prony, GuyTon, and Rochon, onTucsday April 10, 180y.
We know that the invention of achromatic glasses is one of the grandest discoveries of the last century. We are in- debted for it to a celebrated geometrician, who has enriched the mathematical sciences with the most astonishing con- ceptions. In 1747 Euler entertained the sublime idea of correcting, by the employment of several diaphanous sub- stances, the aberration resulting from the decomposition of light in spherical glasses. 'J his was the more valuable, be- cause philosophers had been led to believe, according to the experiments of Newton, that there was no refraction when there was no dispersion, — thus" banishing all hope of destroy- ing the colours in glasses.
Euler informs us, in the Memoirs of th* Academy of Peters- burgh, that some experiments made upon meniscus glasses, the concavities of which he filled with various liquors, proved that the different refrangibility of the rays of light could be diminished, and even reduced to nothing, (these are the ex- pressions of this great man, whose modesty was equal to his talents,) by employing two or more transparent sub- stances. He adds, what is very remarkable, that the won- derful structure of the eyes, which represent the images of objects from their posterior extremity, suggested to him that it would be possible to diminish, and even to annihilate, all the defects to which the different refraction of the ravs of light at that time seemed to be necessarily subjected. " Here again, " says Euler, " we recognise the power of the Deity, as well as his infinite wisdom." He informs us at the same time, that his opinion was attacked by John Dol- lond, an eminent optician of London : but upon some ob- servations of M. Klmgeiistierne, he ascertained, after amul- Vol. 33. No. 133. May 1809. Y tiplicity
338 Report on the ponderous Flint Glass intended
tiplicity of experiments, that the great inequality of the dispersive powers which takes place in two kinds of glass, vulgarly known by the names of flint and cronn glass, was sufficient for realizing the idea of Euler, and thereby good achromatic glasses were obtained. Dollond's success procured him a patent in 1759, wich was called in question, however, by Valtines in Westminster Mall. Valtines proved that the ingenious Chester Morehall had constructed glasses long before Dollond, perfectly achromatic, and of an im- mense amplifying power. So early as the year 1754, M. Ayscough, an optician of Lancaster, possessed one of these instruments, as did also Dr. Smith. These facts, although but little known, deserve to be published, and were authen- ticated by lord Mansfield, who maintained Dollond in his privileges, merely because the benefit of a patent does not belong to him who has the first scientific idea of an inven- tion, but to him who enables the public to enjoy the ad- vantages of the discovery.
So far Mr. Dollond deserved a recompense; and the cele- brated achromatic instrument with a triple object glass which lue presented to the Royal Society excited a great sensation in the scientific world.
The Academy of Sciences, on being informed that instru- ments were made at London upon the principles of Euler, and which magnified one hundred times the diameter of the objects with the degree of clearness and distinctness requisite in delicate observations, proved by ingenious inquiries, that it attached the highest possible value to the new discovery in question. Two eminent geometricians, Messrs. Clairaut and D'Alembert, have left nothing to desire upon the in- tricate theory of the construction of these instruments. They fixed the spherical curvatures of glasses of unequal dispersive forces, which reduce to the minimum the aberra- tions of refrangibility and sphericity.
M. Clairaut afterwards ascertained by experiments, Chat the lapidaries of Paris, who endeavoured to imitate the dia- mond in their glassy compositions, made use of a kind of glass vulgarly known by the name of strass ; the dispersive power of which is greater than that of flint glass. But this
glass,
for the Manufacture of Achromatic Glasses* 33£)
glass, to which an artist of the name of Strass had given, by means of the oxide of lead, a gravity equal to that of the diamond, is generally so soft {gelalineux) , that it is very diffi- cult to succeed in employing it usefully in the manufacture of achromatic object glasses, which require glasses not only perfectly homogeneous, but also blown glasses, according to the remarks of the most eminent opticians, who have discovered, in the practiee of their art, the advantages of these blown glasses over those which were run into crucibles.
M. Loysel, in his Essay upon Glass Making, gives us the composition of a glass imitating the dispersion of the diamond : it is, he informs us, with 100 parts of white sand, washed in muriatic acid, combined and fused with 150 parts of red oxide of lead, to which must be added 30 parts of aerated and calcined potash, and ten parts of calcined borax, that the lapidaries produce, in small furnaces, the crystal which imitates the diamond, and which has the same weight ; its specific* gravity being as to water 35 to 10. They sometimes add one part of oxide of arsenic ; but this com- position, which they allow to cool in crucibles, produces but very small masses, which can only be used in making trinkets.
If, in the origin of the invention of achromatic glasses, M. Clairaut made use of this glass in the construction of some achromatic object glasses, it was because l7e was de- sirous to make an useful application of his formula upon glasses the dispersive power of which was much greater than that of flint glass : but M. de l'Etang, whom he charged with this work, remarked to him that blown glass, such as flint and crown glass, was requisite for good object glasses. On this account the Academy of Sciences, at the suggestion of the government, who were unwilling that France should be tributary to England in the article of glass, proposed in 1766, as the subject of a prize dissertation, the best process for imitating in France a ponderous glass exempt from all defects, and having all the properties of flint glass.
This prize was granted in 1773 to M. Lebaude, the ma- nager of a glass-work, and his Memoir was printed among the Memoires des Savaus Etrangeres fur 1774.
Y 2 M, LebanJe,
340 Report on the ponderous Mint Glass intended
M. Lebaude, on this occasion, merely produce! specimens of ponderous glass, and which could not satisfy the wants of opticians: the Academy was therefore obliged, in 17S6, to renew the same subject as a prize dissertation, and the sum offered was 12000 -ivres. In announcing the subject proposed, a process was required, by means of which the quantity of ponderous glass necessary to supply the wants of commerce might be constantly supplied, and without the 0 defects of flint glass.
Since the above period, essays have certainly been pre- sented, but they were either too imperfect or too meagre for attaining the essential object which government had in view > namely, that of furnishing France vyith all the ponderous glass requisite for optical instruments, without having re- course to foreigners. This enterprise was not unattended with difficulties in its execution, -because the heads of great glass-works, who alone could enter into these delicate and difficult inquiries with any chance of success, could not flatter themselves that the sale to opticians, of ponderous glass blown without any defects, was likely to reimburse them for the enormous expense this degree of perfection requires. This consideration is sufficient to show, that we cannot as- similate simple essays with works which should serve to vivify and extend an important branch of industry and commerce.
M. Doufourgerais, manufacturer of glass to the emperor, already known by the celebrity of his manufactory of cry- stal glass at Mont Cenis, has certainly excited a lively in- terest among us, on account of the decided preference which the produce of his industry has generally obtained over the glass of England and Bohemia, although he had to surmount many powerful obstacles. The Institute could not view without extreme satisfaction the works on a great scale which this ingenious and zealous manufacturer has recently exe- cuted. One specimen consists of 600 kilogrammes of a glass weightier than flint glass. It is 9000 millimetres thick, and L70 centimetres high. He has already sold upwards of 300 kilogrammes of it to opticians, and the remainder will soon be bought up also, without the price being adequate to the
capital
fur the 'Manufacture of Achromatic Classes. 341
capital generously sacrificed for the attainment of an object, the importance and utility of which he knew how to ap- preciate.
We shall now give an account to the Institute of the na- ture and quality of the ponderous glass which has been sub- mitted to our examination.
We ought to premise, that the most eminent opticians are fully satisfied of the qualities of the glass in question, and that a great number of achromatic telescopes have been made with it. We now call the attention of the Institute to ^ letter to M. Doufourgerais from M. de Freminville, chief engineer of roads and bridges, who is specially charged with furnishing the telegraphs and the navy with the glasses re- quired for the observation of signals.
" Pieces of glass from your magazine, taken at random, and subjected to the necessary operations for employing them as optical glasses, produced object glasses comparable to the best of Dollond's of the same dimensions. You have there- fore attained, and I am proud to bear witness to it, the highest degree of perfection ever possessed by English glass, whether I consider it in a commercial or scientific point of view, since in your article beauty and utility are united to cheapness."
This impartial testimony from a person well acquainted with optical instruments, we are happy in being able to corroborate from our own experience. The glass made by M. Doufourgerais is heavier than flint glass: one of us measured the gravity of the former in the hydrostatic ba- lance, and found it to be 3,588 with respect to distilled water, while the heaviest flint glass is only 3,329.
A prism of the glass made by M. Doufourgerais, having an angle of two degrees, ceases to colour objects the instant we place it against a prism of common glass, (such as the blown glass made at Cherbourg, which differs very little from crown glass,) when its angle is 18 degrees : from the experiments therefore of one of your committee, it appears that the dispersion which takes place in the glass made by M. Doufourgerais, is, to that observed in the most ponderous
Y 3 Aim
34-2 . - QUt$l, &e.
flintglass, as 36 to three. The mean refraction is also stronger, being-Id, while that of flint glass is 16Q.
We caused a piece of the new glass to be cut into lenses of 16() millimetres focus; and we can assure the Institute, that this rigorous examination convinced us that France may now dispense entirely with flint glass in the construction of good achromatic glasses, so necessary in the naval and military Service. The above glasses, which we have examined and compared with English glasses, prove that the eulogies we bestow on them are well founded ; we do not mean to say, however, that, when taken hv.hscriminalely, the' glass made byM. Doufourger-ais can be used for the large object-glasses used by astronomers in delicate observations : in this case, as in flint glass, it would be necessary to pick out a piece, in order to avoid the air- drawn threads and streaks from which blown glass is rarely free; and we ought not to require, in a large mass of glass, -a perfection which is perhaps chimerical, for instruments of no importance in a commercial point of yiew, however valuable in scientific pursuits. We must ob- serve, nevertheless,, that the glass made by M- Doufourgerais, although very ponderous, has generally fewer threads than flint glass, and its clearness equals, if if does not surpass, that of English glass.
. The largest glass made with the article manufactured by M. Doufourgerais, and wnich we examined, was only eight decimetres in length. Its object glass had an aperture of 60 millimetres, and it magnified the diameter of objects 30 limes. With astronomical eye-glasses we can make it ex* hibit a much greater magnifying power: but this increase is not of any use in the examination of terrestrial objects. We doubt if it has all the aperture which it can support, because opticians must change the ordinary proportions, when they u.e a glass which has a stronger, dispersion than $tras$.
In 1 7 f 4 , Nicholas Fust published a work in French, with
the following title : " Instruction detaillce pour porter les
Lunettes de twites les differentes Especes au plus haut Dcgre
jectlun dint flies dont susceptibles, tirte de la Theorie
i l dioptrique
Description of an improved Telegraph. 343
diopiri/jue da AT. Euler, et mise a la Portee de tons ies Onvriers en ce Genre.'' This work ought to be in the hand* of every optician : but jt is scarce in France, having been printed at Petersburg.
Artists will learn, from the above book, the advantages and changes which it is important to observe in the use of a kind of glass with a greater dispersive power than that of flint glass. But these inquiries are interesting to opticians only, and are foreign to the labours of M. Doufourgerais, who seems to us to merit in every respect the encouragement and protection of the Government, as well as the approbation of the Institute. — Signed De Prony, Guyton, Rochon. loTbe : Class approves of the above report, and assents to its conclusions.
Signed, Delambre, perpetual secretary. ■' . . . ~~ ' ~"
L.XI.I. Description of an improved Telegraph, By Major Charles Le Hardy, of the Island of Jersey*.
XJLaving discovered a mode of communicating by signals, which to me seems to unite every advantage that can be ex- pected for that mode of communication, I beg leave to trans- mit to you a plan of it, and to write a few explanatory lines upon the subject.
The telegraph, of modern invention, is an improvement on communication by signals, which has been in use for many ages. Monsieur Chappc was, I believe, the first who proposed a machine for that purpose, which was put in ex- ecution about the year 1793. Since that time several modes have been proposed by different persons, none of -which seem to have fully attained the object. A machine of this kind should be simple, and easy to comprehend. All those which have come to my knowledge are executed by com- binations, which render them too complicated for common
* From Transactions of the Society for the Enconrageme?* nfAus, Mam/fa r-
ture, and Commerce, for 1808. The silver medal of the Society was voted
to Major Charles Le fclardy for this communication.
. Y 4 use>
314 v Description of an improved Tckgrap'\
use, and therefore liable to many errors. That which I now submit to your consideration, seems to me to have removed every objection of the kind ; it is simple, easy to compre- hend, and extensive in its means its combinations, which by simple numeration may be carried to 40,000, might with ease be extended to almost infinite numbers; bat the present seems sufficient to answer every purpose. All the words in Entick's Dictionary amount to about 25,000; every one of which may thus be numbered. With how much more di- spatch would a letter be communicated by signals which express words, than by signals which express only letters ! Words may be forwarded as fast as they can be looked for in a dictionary ; and even whilst only an equal number of letters could have been communicated by the present mode. Another advantage resulting; from the use of words in tele- graphic correspondence is, that the words of the same meaning in the several languages having the same number, correspondence may be carried on from one language into another, which though not grammatically correct, yet would be sufficiently intelligible.
Proper names must be spelt, which may easily be done, every letter having a corresponding number.
Though the use of telegraphs has to this time been con- fined to military purposes, yet a machine of this kind is well adapted to accelerate commercial communication from one end of the kingdom to the other. The arrival, the de- parture of vessels, the various transactions of commerce, might be speedily announced, to the very great advantage of trade. By this method inaccessible places might com- municate their wants, and correspondents, though at a di- stance of five or six miles, might erect them for a trifling expense. I made the experiment with one of eight feet by ten, and, with the use of a telescope, I took down every number from a distance of a mile and a half. I remain, sir,
Your most obedient and humble servant,
Charles Le Harqx\
London, Jan. 13, 1808.
To C. Taylor, M.D. Sec,
Ti.ejerev.ce
Description of an improved Telegraph. 345
Reference to the Engraving of Major Charles Le IIakdy's Telegraph. See Plate VI J I. Figs. \9 2, 3, and 4.
This machine is intended to express numbers, which mav be seen at a distance, and to which words may be referred at pleasure.
Fig. 1 represents a front view of the machine — lit is com- posed of nine bars or radii, answering to the nine figures of arithmetic, as numhertd in the plate. The four polygonal or concentric bars, A. B.C. 1). which intersect the radii, are for the decimals ; thus A stands for units, B for tens, C for hundreds, D for thousands. Over each of these concentric bars or circles, an index,, as that marked H, fig. 2, tra- verses, which marks the number of thousands, of hundreds, of tens, and of units, as far as ten thousand ; for instance, if it is required to make the number 920-2, turn the hand II in the circle D of thousands to the radius 9, then the hand II in the circle C of hundreds to the radius 2, then, as there are no tens, turn the hand to the radius 2, upon the circle A of units ; but as ten thousands are not sufficient to ex- press the number of words in the English language, two square boards are added in the corners, of which that mark- ed E is equal to 10,000, that marked F to 20,000, and both being shown together, are equal to 30,000, which, with the numbers made on the circles, bring it op to 40,000, which number is more by many thousands than all the words in tiie Englisti language.
Fig. 2 is a view of the mechanism which works the sig- nals round : this is done by means of a rack whee) at ]", upon which is firmly fixed the hand with its signal board H; this wheel is made to revolve by means of a rack L, which being raised or lowered, makes it go backwards or forwards; this rack is set in motion by the pinion K, to which is "fixed a winch, as M, fig. 3. To prevent the necessity of inspect- ing the signals, the wheel I, to which is fixed an index, as at N, fig. 4, is added, which revolving in the same time as the signal board H, marks the number of the decimal, so that it may be worked correctly from within doors. O, pg. 4, is a bolt to stop the hands at any given point, by
nicans
340 Description of an Improvement in Jury Masts.
means of a wheel with four notches O fixed to the pinion. Fig. 3 is a side section of the machine, the lines aaaa re- present boards, upon each of which is fixed the mechanism, fig. 2. b b 1 1 are the hands and signal boards, one of which is shown at H, fig. 2. The square boards E and F, fig. 1, are fixed upon iron bars which pass through the bars or radii 4 and G, .and have each of their ends made to move in holes in the radius 5, and in the frame at ii, fig. 1, upon which they Izvti a quarter round, by means of cross bars at gg, to each end of which ropes or wires hk are fastened, and which are connected with two lever?, one of which is shown at P, fig. 3, the raising or depressing of which makes them appear or disappear as required.
■ ■ - i - — i' , ■ ■ i •.. • — i
LXIIT. Description of an Improvement in Jury Masts. By Capt. William Bolton, of the Royal tttivy1*.
TJ Sln'
Jjlerewith you will receive the model of a plan for fitting
ships' jury masts, to be formed from the. spare spars usually- carried on board king's ships, and in every merchantman that is properly found. By having jury masts so fitted, ships will be enabled to carry as much sail as on the usual regular mast ; the great use of which I need not dwell on, only observing that it may be of great importance to fleets after a general action, or when in want of proper lower masts, either at home or abroad, and enable ships, after the loss of their mast, to prosecute their voyage, or service, without any deficiency of sail.
I beg you will be pleased to lay it. before the Society, and I have the honour to be,
Sir, your obedient humble servant,
Wm, Bolton,
His Majesty's Ship Fisgard, Shcerness', Oat. 31, 1807.
To C. Taylor, M.D. Sec.
* From Transactions of the Society for tlie Encouragement of Arts, Manu~
s Hiref, and Commerce, for 1808. The silver medal of the Society was
voted to Capt. William Bolton for this communication,
REMARKS,
Description of an Improvement in Jury Masts. 347
REMARKS.
In the model in the Society's possession the main mast h broken about one-third of its length above the deck, proper partners are secured on the deck, in which a hand mast and spare main top mast are fixed on each bide of the broken main mast, and secured thereto by two spare caps, morticed on a square made in its centre. A strengthening cap, move- able on these additional masts, connects them, and the upper parts of these masts are secured firmly by trustle trees j-n the main top. The foot of a spare fore top mast passes through a cap made from strong plank, morticed into the heads of the two temporary masts above mentioned, goes through the main top, and rests in the moveable strength- ening cap, which connects those- two masts, and enables the fore top mast to be raised to any height which the main top will admit, and be then firmly secured by the upper cap, the main top, and the strengthening cap below it. The fore top mast being thus adjusted, the cross trees and top gallant mast are mounted upon it^ which completes th$ whole business.
Two cap? are the only things necessary to be made ex- pressly for the purpose, the other articles being usually ready en board the ship.
Reference to the Drawing of Capt. Bolton's Jury Mast, Plate X. Figs. 1, 2, 3. Figs. 1, 2, and 3, where A A represents the partners or pieces of timber which are bolted to the quarter deck for the mast to rest upon. 13 is the stump of the lower mast, which is cut square at the top, and of the same size as the head of the mast originally war. ; upon this square, the main and spare lower caps a a are fixed ; two mortices must be cut in the partners A A to receive squares made at the lower ends of the two temporary masts D D, which are supported by the caps aa; one of them is a spare main topmast, the other a hand mast ; these two support the main top E, ad- ditional squares being made on the trustle trees to receive each of them, h is a cap shown in fig. 2, made of four-inch plank doubled for the purpose, and fitted upon the heads of
the
r-43 Improvement in Anchors.
the masts DD, for a top mast FF, the heel of which resis in a mortice made in the stump or the lower mas* : it is also steadied by a double cap G, separately shown in fig. 3, on which it fids finally on the top. The top- gallant mast II is fixed to the mast F by the top and cap in the usual manner. The figures 2 and 3 show the caps separated from the masts, and are the only things necessary to be made for the pur- pose; and the object of the cap, fig. 2, is to steady and pre- vent any wringing of the lower jury mast, and to fid the top mast whenever it is reefed. The fore top mast FF ap- pears in two separate pieces, on account of its length.
LXIV. Improvement in Anchors, to render them more du- rable and safe for Ships ; and an improved Mode of Fish- ing Anchors. By Capt. H. L. Ball, qj the Rcri/al Navy*,
SIR,
JL he great expense of timber in the navy for anchor stocks, and the frequency of their failing or giving way in the cen- tre, where the square of the anchor is let into the stock, have induced me to offer to the Society of Arts, &c, a plan of an anchor which may be cheaper in construction, and more likely to hold in various situations than those in com- mon use.
The model I have sent will sufficiently explain my inten- tion, and show how beneficial it may be in strengthening the anchor stocks. I wish much to notice to you its proba- bility of holding in the ground longer than other anchors, on account of the additional weight of the stock ; and this will more particularly be the case in banks which shelve suddenly down from the shore, such as at St. Helena, Caw- sand Bay, and indeed in most of the islands in the West Indies. The proportion of additional iron, as explained by my model, is in all anchors to be twice and a half the dia- meter of the shank from each side at the stock, and of
* From Transactions of the Society for the Encouragement of Arts, Manufac- tures, and Commerce, for 1808 The silver medal of the Society was voted
to Capt. H. L. Ball for this communication.
course
Improvement in Anchors, 319
course this mode will supply the place of the present nuts, which are only intended to prevent the stock from slipping in and out, whenever it becomes loose ; which accident anchors are very liable to in hot climates. My anchor stocks will save a considerable quantity of the finest limber, and give much greater security.
I likewise beg leave to offer to the Society a model of a double fish hook, for the purpose of fishing the anchor, an operation which, in the common mode of doing it, is fre- quently attended with accidents both to the ship and crew, from the anchor suddenly slipp ng unexpectedly in raising it to its proper position.
I flatter myself that these improvements will meet with the Society's approbation.
I am, sir, your most obedient humble servant,
H. L. Ball.
Lower Mitchatn, Feb. 13, 1808.
To C. Taylor, M.D. Sec.
Reference to the Engravings of Capt. H.L. Ball's Method of Fishing an Anchor. See Plate X. Figs. 4 and 5.
Fig. 4, PI. X., represents captain Ball's method of fish- ing an anchor. Fiji. 5 shows an enlarged view of his double hooks used for that purpose.
In the usual operation of heaving an anchor, it is drawn up by the cable until it appears above water; the cable will not now raise it higher, it is therefore bowsed up by the cat block a, fig. 4, from the cat head b, the cable d being slackened out as it rises. When it is got up as high as the cat block will raise it, a strong hook, called the fish hook, fastened to a rope e, which is suspended by a tackle from the shrouds, is hooked to the anchor at the bottom of the shank, and thus the arms of the anchor are elevated above the stock, until one of the flukes is brought up to the tim- ber heads ffy to which it is made fast by a rope and chain, called the shank painter. In this operation the fish hook sometimes slips, and occasions mischief; to remedy which, captain Ball has applied two hooks instead of one, which keep firmer hold. These hooks are shown upon an enlarged scale at gg> tig. 5, attached to the rope e; each of these
hooks
950 Method of ascertaining the Value
books takes one of the arms of the anchor, close to tht
shank, and holds it firmly, ii are two small lines made fast
to the hooks, to direct them so as to get proper hold of the
anchor.
Reference to the Engraving of Captain H. L. Ball's J/?z- provement in the Formation of Anchors. See Plate X. Figs. 6, 7, and 8.
This anchor, in external appearance, differs very little from the common anchor ,• the improvement consists in forming and fixing of the shank of the anchor to the stock. The stock a a, figs. 6 and 7, is made of two pieces of oak bolted together, and well secured by hoops. In the common method, in order to prevent the anchor stock from slipping off the shank, a square projection h b, fig. 8, is forged upon the shank ; this is improved by captain Ball, as shown in fig. 6, where this projection dd is extended on each side of the shank, far enough to receive two bolts through each of these extensions, which bolts hold firmly together the two pieces of timber which form the stock, and secure the stock fast to the shank. Two iron hoops, fig. 7, e e, are driven on the stock between the. bolts, and ffff are other hoops, and g ggg are tree-nails to strengthen the whole.
LXV. Method of ascertaining the Value of Growing Timler Trees, at different and distant Periods of Time. By Mr. Charles Waistell, oj High Holborn.
[Concluded from p. 332.]
Observations on Tables I. and II,
X he preceding tables furnish us with the following useful information, viz.
1st. That all regular growing trees, measured as above, as often as their age is increased one fourth, contain very nearly double their quantity of timber.
2d. That when a tree has doubled its age, its contents "will be eight-fold.
3d. That when a tree has doubled its age, the annual growth will be increased four-fold,
8 4th,
of Growing Timler Trees. 35 1
4th. Consequently, that when a tree has doubled its age, the proportion that its annual increase bears to the contents of the whole tree is then diminished one-half.
This last observation explains ho^ it comes to pass that a tree, when its age is doubled, the rate per cent, per annum that its increase then bears to the content of the whole tree, is diminished one-half.
It may not be unuseful to observe, that the rate percent. of increase in the last columns, is the same as the rate per cent, that the increase of the tree that year will pay for the money it. was worth the preceding year. <*
In the two preceding tables, we find that the rate of in- crease per cent, per annum is the same in both at the same ages, although the quantity of timber in the second table is six times as much as in the first table in trees of all ages j therefore, when the age of a tree is known, tl*e rale;per cent, per annum of its increase is known on inspecting these tallies,^ whether the tree lias grown fast or slow ; provided the growth of the tree has been regular, and that it has con-% tinned its usual growth.
And having the age, girt, and height, of any tree given, we can readily calculate what quantity of timber it will eon- tain at any future period whilst it continues its usual rate of growth. *»f ^ to *-r
A Table showing the Number of Trees to be cut out in thinning of Woods, and the Number left standing at every Year., from 20 up to 6*1 Years.
Tn the 24th Volume of the Transactions of the Society of Arts, See. page 75, Mr. Salmon, in a paper on the Ma- nagement of Fir Woods, says, t( the distance of trees from each other should be one-fifth of their height/* At that distance, which is probably sufficient for fir trees, the fol- lowing will be the number ofi an acre, and the number to be cut out at the ages and heights under mentioned, and the number of feet they will then contain in the bole, when measured to the top of the leading shoot. These tree* are supposed to increase twelve inches in height, and one in
circumference,
352 Mttliod of 'ascertaining the Value
circumference, annually* and to have been at first planted
TABLE lit.
four (ctt apart.
|
<u |
Number |
||||||||
|
Yenrs of.1 |
of Trees |
Contents |
Number |
||||||
|
and feet |
Girt |
Contents. |
on an |
of the |
to be |
Contents. |
|||
|
high. |
3 |
Acre. |
v.'hule. |
cut our. |
|||||
|
inch. |
it. |
in. |
pts. |
feet. |
feet. |
feet. |
|||
|
£0 |
24 |
0 |
10 |
5 |
4* |
2722 |
2362 |
83 9 |
727 |
|
2i |
3 |
1 |
6 |
0 |
4-S |
1883 |
2824 |
494 |
741 |
|
28 |
H |
2 |
4 |
7 |
5'6 |
1389 |
33'08 |
325 |
776 |
|
$2 |
4 |
3 |
6 |
8 |
6-4 |
1063 |
3779 |
223 |
792 |
|
36 |
4± |
5 |
0 |
9 |
7'2 |
840 |
4252 |
1 60 |
810 |
|
40 |
5 |
G |
11 |
4 J S- |
6S0 |
4/2-2 |
lit |
819 |
|
|
44 |
H |
9 |
2 |
111 8-S |
562 |
5194 |
90 |
831 |
|
|
48 |
6 |
12 |
0 |
0 96 |
472 |
5664 |
70 |
840 |
|
|
52 |
HI |
15 |
3 |
0 10-4 |
402 |
6130 |
55 |
838 |
|
|
55 |
7 ! |
19 |
0 |
8 11-2 |
317 |
6611 |
45 |
857 |
|
|
60 |
7k \ |
23 |
5 |
2 12- |
302 |
70/6 |
37 |
866 |
|
|
64 |
8 1 |
28 |
5 |
4 lit** |
265 |
7537 |
And if trees be periodically thinned out to the distance of one- fifth of their height, and that they increase fifteen inches in height, and one inch and a half in circumference, annually, the number of trees on an acre, and the number to be cut out at different periods, and the number of feet they will respectively contain at those periods, will be as
under, viz.
TABLE IV.
|
j i |
0 |
Number |
1 |
1 |
||||
|
c |
of Tree* |
Content |
s Number |
|||||
|
Ajje. !H<rht. Girt. |
Contcnts. |
en |
on an |
of the |
j to be |
Contents. |
||
|
I j |
0 |
Acre. |
whole. |
[cut out- |
||||
|
vears. |
feet, finch. |
ft. in. pta |
feet. |
feet. |
feet. |
|||
|
16 |
20 |
3 |
1 3 0 |
4 |
2722 |
3402 |
960 |
1225 |
|
20 |
25 |
3i |
2 5 3 |
5 |
1/42 |
4246 |
532 |
1290" |
|
24 |
30 |
4f |
4 2 7 |
6' |
1210 |
5100 |
322 |
1357 |
|
28 |
35 |
H |
6 8 4 |
7 |
888 |
59-14 |
208 |
1392 |
|
32 |
40 |
6 |
10 0 0 |
8 |
680 |
0800 |
143 |
1430 |
|
3o |
45 |
<*| |
14 2 10 |
9 |
537 |
7644 |
102 |
1452 |
|
40 |
50 |
n |
10 6 4 |
10 |
435 |
8494 |
75 |
1464 |
|
44 |
55 |
BJ |
25 11 10 |
11 |
360 |
9355 |
58 |
1507 |
|
48 |
60 |
9 |
33 9 0! |
12 |
302 |
10192 |
45 |
1518 |
|
52 |
65 |
91 |
42 10 10 1 |
13 |
257 |
11020 |
35 |
1501 |
|
50" |
70 |
101- |
53 7 0 |
14 |
222 |
11 895 |
29 |
1553 |
|
60 |
;•' Hi |
65 10 11 |
15 |
193 |
12720 |
23 |
1515 |
|
|
C4 |
KO |I2 |80 0 Ol |
16 1 |
170 |
[3600 |
1 |
It
of Growing Timber Trees. 353
It will be observed in all these tables, that when trees have doubled their age, there are only one- fourth of the number remaining on an acre, in consequence of their distance being doubled ; but as each tree will then have increased its con- tents eight-fold, therefore the number of feet on an acre must be then doubled. Above, at 64 years of age, there is exactly double the number of feet that there is at 32 years of age.
And if trees be periodically thinned out to the distance of one- fifth of their height, and that they increase eighteen inches in height, and two inches in circumference, annually, the number of trees on an acre, and the number to be cut out at different periods, and the number of feet they will then respectively contain, will be as under, viz.
TABLE V.
|
6 |
Number |
|||||||
|
0 |
of Trees |
Contents |
Number |
|||||
|
Age. |
Hght. |
Girt. |
Contents. |
CO |
on an |
of the |
to be |
Contents. |
|
Q |
Acre. |
whole. |
cutout. |
|||||
|
years. |
feet. |
inch. |
ft. in. pt. |
feet. |
feet. |
feet. |
||
|
11 |
18 |
3 |
1 1 6 |
4' |
2722 |
3062 |
S3p |
943 |
|
16 |
24 |
4 |
2 8 0 |
4-8 |
1883 |
5021 |
673 |
1794 |
|
20 |
30 |
5 |
5 2 6 |
6' |
1210 |
6302 |
370 |
1927 |
|
24 |
36 |
6 |
900 |
72 |
840 |
7560 |
223 |
2007 |
|
28 |
42 |
7 |
14 3 6 |
8-4 |
617 |
8817 |
145 |
2072 |
|
32 |
48 |
8 |
21 4 0 |
9'0 |
472 |
IOO69 |
99 |
2112 |
|
36 |
54 |
9 |
30 4 6 |
10'8 |
373 |
11314 |
71 |
2153 |
|
40 |
60 |
10 |
41 8 0 |
12* |
302 |
12583 |
51 |
2166 |
|
44 |
66 |
11 |
55 5 6 |
132 |
250 |
13864 |
40 |
2218 |
|
48 |
n |
12 |
72 0 0 |
144 |
210 |
15120 |
32 |
2304. |
|
52 |
78 |
13 |
91 6 6 |
156 |
178 |
I6294 |
24 |
2197 |
|
56 |
84 |
14 |
114 4 0 |
16-8 |
154 |
17607 |
20 |
2286 |
|
60 |
90 |
15 |
140 7 6 |
18- |
134 |
18843 16 |
2250 |
|
|
64 |
90 |
16 |
170 8 0 \ |
19-2 |
118 |
20138 1 |
But if the trees be first planted four feet apart, and be periodically thinned out to the distance of one-fourth of their height, and that they increase twelve inches in height, and one in circumference, annually, the number of trees oa an acre, and the number to be cut out at the ages and heights under mentioned, and the number of feet they will respec-
Vol. 33. No. 133. May 1800. Z tively
$34 Method of ascertaining the Value
tively contain in the bole, when measured to the top of the leading shoot, will be as under, viz.
|
TABLE VI. |
||||||||
|
<u |
Number |
|||||||
|
Years old |
C |
>f Trees |
Contents |
tfumber |
||||
|
and feet |
Girt. |
Contents. |
on an |
of the |
to be |
Contents |
||
|
high. |
5 |
Acre. |
whole. |
cut out. |
||||
|
inch. |
ft. |
in. pt. |
feet. |
feet. |
feet. |
|||
|
J6 |
2 |
0 |
5 4 |
4 |
2722 |
1209 |
98O |
435 |
|
20 |
»1 |
0 |
10 5 |
5 |
1742 |
1512 |
532 |
461 |
|
24 |
3 |
1 |
6 0 |
6 |
1210 |
1815 |
322 |
483 |
|
28 |
H |
2 |
4 7 |
7 |
888 |
2115 |
208 |
4()5 |
|
32 |
4 |
3 |
6 8 |
8 |
6*80 |
2417 |
143 |
508 |
|
36 |
H |
5 |
0 9 |
9 |
537 |
27 18 |
102 |
516 |
|
40 |
5 |
6 |
11 4 |
10 |
435 |
3020 |
75 |
520 |
|
44 |
* |
9 |
2 lj |
11 |
360 |
3327 |
58 |
536 |
|
48 |
6 |
12 |
0 0 |
12 |
302 |
3624 |
45 |
540 |
|
52 |
61 |
15 |
3 0 |
13 |
257 |
3919 |
35 |
533 |
|
56 |
7 |
19 |
0 8 |
14 |
222 |
4230 |
29 |
551 |
|
60 |
7\ |
23 |
5 2 |
15 |
193 |
4522 |
23 |
538 |
|
64 |
8 |
28 |
5 4 |
16 |
170 |
4835 |
20 |
568 |
|
68 |
8i |
34 |
1 4 |
*7 |
150 |
5116 |
16 |
545 |
|
72 |
9 |
40 |
6 0 |
18 |
134 |
5427 |
14 |
567 |
|
76 |
9j |
47 |
7 6 |
19 |
120 |
5715 |
12 |
571 |
|
80 |
10 |
55 |
6 8 |
20 |
108 |
6000 |
10 |
555 |
|
84 |
10| |
64 |
3 8 |
21 |
08 |
6301 |
8 |
554 |
|
88 |
11 |
73 |
11 4 |
22 |
90 |
6655 |
8 |
5Q1 |
|
92 |
111 |
84 |
5 H |
23 |
82 |
6928 |
7 |
591 |
|
96 |
12 |
96 |
0 C |
24 |
75 |
7200 |
6 |
576 |
|
100 |
121 |
108 |
6 C |
25 |
69 |
7486 |
5 |
542 |
|
104 |
13 |
122 |
0 8 |
26 |
64 |
7811 |
5 |
6lO |
|
108 |
131 |
136 |
8 3 |
27 |
59 |
8037 |
4 |
546 |
|
112 |
14 |
152 |
5 4 |
28 |
55 |
8384 |
4 |
6O9 |
|
116 |
141 |
169 |
4 5 |
29 |
51 |
8659 |
3 |
508 |
|
120 |
IS |
187 |
6 C |
30 |
48 |
9000 |
3 |
562 |
|
124 |
151 |
206 |
10 7 |
31 |
45 |
9309 |
3 |
620 |
|
128 |
16 |
227 |
6 8 |
32 |
42 |
0557 |
2 |
455 |
|
132 |
161 |
249 |
6 8 |
33 |
40 |
9982 |
And if the trees be periodically thinned out to the distance of one-fourth of their height, and that they increase 15 inches in height, and one inch and a half in circumference annually, the number of trees on an acre, and the number to be cut out at the different periods under mentioned, and the number of feet they will respectively contain at those periods, will be as under, viz.
TABLE
of Growing Timber Trees,
355
|
TABLE VII. |
||||||||||
|
V |
Number |
mm |
||||||||
|
a |
of Trees |
Contents |
Number |
|||||||
|
Age. |
Hght. |
Girt. |
Contents. |
» |
on an |
of the |
to be |
Contents* |
||
|
S |
Acre. |
whole. |
cut out. |
|||||||
|
years. |
feet. |
inch. |
ft: |
in. |
pl |
feet. |
feet. |
feet. |
||
|
12 |
15 |
H |
0 |
6 |
3 |
4' |
2722 |
1417 |
9S0 |
510 |
|
10 |
20 |
3 |
1 |
3 |
0 |
5' |
1742 |
2177 |
0'27 |
783 |
|
20 |
25 |
31 |
2 |
5 |
3 |
625 |
1115 |
2717 |
341 |
831 |
|
24 |
30 |
4l |
4 |
2 |
7 |
T5 |
774 |
3262 |
205 |
S68 |
|
28 |
35 |
5.t |
6 |
8 |
4 |
8-75 |
568 |
3802 |
133 |
800 |
|
32 |
40 |
6 |
10 |
0 |
0 |
io- |
435 |
4350 |
91 |
910 |
|
36 |
45 |
61 |
14 |
2 |
10 11*25 |
344 |
4897 |
66 |
938 |
|
|
40 |
50 |
74 |
19 |
6 |
4 12-5 |
278 |
5428 |
48 ' |
937 |
|
|
44 |
55 |
8.t |
25 |
11 |
10] 1375 |
230 |
597(> |
37 |
962 |
|
|
48 |
60 |
9 |
33 |
9 |
Oi 15- |
1Q3 |
6513 |
29 |
978 |
|
|
52 |
65 |
9^ |
42 |
10 |
10 1625 |
164 |
7036 |
22 |
943 |
|
|
56 |
70 |
lp£ |
53 |
7 |
o, 17-5 |
142 |
76OS |
19 |
1018 |
|
|
60 |
7$ |
1U |
65 |
10 |
11 1875 |
123 |
8106 |
15 |
988 |
|
|
64 |
80 |
12 |
SO |
0 |
O1 20- |
108 |
8640 |
And if the trees be planted at 4| feet apart, and be peri* odically thinned out to the distance of one-fourth of their height; and that they increase 18 inches in height and two inches in circumference annually, the number of trees on an acre, and the number to be cut out at the different periods under mentioned, and the number of feet they will then re- spectively contain, will be as under, viz.
TABLE Vin.
|
0 |
Number, |
|||||||
|
c |
oi Trues Conter.tr |
Number |
||||||
|
Age. |
Hght. |
Girt. |
Contents. |
« |
0:1 an Acre. |
of the whole. |
to be cut out. |
Contents. |
|
vears |
ieet. |
inch. |
ft. in. pts. |
feet. |
feet. |
feet. |
||
|
12 |
18 |
3 |
1 1 6 |
4-5 |
2151 |
• 2419 |
Q41 |
1058 |
|
16 |
24 |
4 |
2 8 0 |
6- |
1210 |
3226 |
436 |
1162 |
|
20 |
30 |
5 |
5 2 6 |
7'5 |
774 |
4031 |
237 |
1234 |
|
24 |
36 |
6 |
9 0 0 |
9' |
537 |
4S33 |
142 |
1278 |
|
28 |
42 |
7 |
14 3 6 |
105 |
395 |
5645 |
9^ |
1329 |
|
32 |
48 |
8 |
21 4 0 |
12' |
302 |
6442 |
63 |
1344 |
|
36 |
54 |
9 |
30 4 0 |
135 |
239 |
7249 |
46 |
13p5 |
|
40 |
60 |
10 |
41 8 0 |
15' |
193 |
8041 |
33 |
1375 |
|
44 |
66 |
li |
55 5 6 |
16 5 |
160 |
8873 |
26 |
1441 |
|
48 |
72 |
12 72 0 0 |
18- |
134 |
9648 |
20 |
1441 |
|
|
52 |
78 |
13 91 6 6 |
19-5 |
114 |
10435 |
16 |
1464 |
|
|
5'j |
84 |
14 114 4 0 |
21- |
98 i 1 1204 |
12 |
1372 |
||
|
60 |
90 |
15 MO 7 6 225 |
86 12093 |
11 |
1546 |
|||
|
64 |
9<> |
16 170 8 0 I 24' |
75 12800 |
It
356* Method of ascertaining the Value
It is difficult in thinning plantations to leave the trees at nearly equal distances. The distances stated in all these tables must be considered the average distances. If, for in- stance, there be 302 trees on an acre, their average distance will be 12 feet, although few of them may stand at exactly that distance.
If the trees be first planted four feet apart, and be peri- odically thinned out to the distance of one-fourth of their height until they are 28 feet high, and to one-third of their height afterwards, and that they increase 12 inches in height and one in circumference annually, the number of trees on an acre, and the number to be cut out at the ages and heights under mentioned, and the number of feet they will then respectively contain in the bole, when measured to the top of the leading shoot, will be as under, viz.
|
TABLE IX |
|||||||
|
4» |
Number |
||||||
|
Years |
a |
of Trees |
Contents |
Number |
|||
|
old and |
Girt. |
Contents. |
rt |
on an |
of the |
to be |
Contents, |
|
feet high |
3 |
Acre. |
whole. |
cut out. |
|||
|
inch. |
feet in. pts. |
feet. |
feet. |
feet. |
|||
|
16 |
2 |
0 5 4 |
4 |
2722 |
1209 |
980 |
435 |
|
20 |
z2 |
0 10 5 |
5 |
1742 |
1512 |
532 |
461 |
|
24 |
3 |
1 6 0 |
6 |
1210 |
1815 |
322 |
483 |
|
28 |
3f |
2 4 7 |
7 |
888 |
2115 |
453 |
1078 |
|
30 |
4 |
2 11 1 |
10 |
435 |
1271 |
133 |
388 |
|
36 |
5 0 9 |
12 |
302 |
1528 |
80 |
404 |
|
|
42 |
H |
8 0 5 |
14 |
222 |
1783 |
52 |
417 |
|
48 |
6 |
12 0 0 |
16 |
170 |
2040 |
36 |
432 |
|
54 |
6i |
If 1 0 |
18 |
134 |
2289 |
26 |
444 |
|
60 |
n |
23 5 2 |
20 |
108 |
2530 |
18 |
421 |
|
66 |
*l |
31 2 4 22 |
90 |
2807 |
Olservations on Table IX. On examining several oak woods, it appeared to me, that the distance of one-third of their height was not too much where the trees were from 30 to 40 feet high and upwards. I have therefore calculated a table according to the distance of one-fourth of their height, till they are 28 feet high, and according to the distance of one-third of their height after- wards.
The
of Growing Timler Trees. 357
The timber to be thinned out before the age of 28 years, will be the same as in Table VI., but at 28 years of age there are 583 feet more to be cut out according to this Table than at the same age in Table VI.; there will, however, be less to be cut out between the ages of 28 and 60 years of age. But if the trees in this Table, in consequence of having more room, were to increase \{ inch in circumference annually, instead of one inch after they are 28 years of age, the pro- duce of an acre at 60 years of age would equal the produce stated in Table VI. at the same age; taking into considera- tion that the value of the 583 feet excess cut out at 28 years of age would then be more than quadrupled, if the money were placed out at five per cent, compound interest. A considerable additional increase in circumference may cer- tainly be expected, in consequence of the trees having al- most double the room in which to extend their branches, and for the admission of those powerful agents, sunshine and air*
Observations on the Tables respecting the Thinning of Woods f and their Produce.
Mr. Salmon is the only person I know of, who has given a general rule for thinning plantations. But as I conceive his distance of one-fifth of their height would leave oaks too close, especially after they had acquired a sufficient length of stem, I have calculated both on his plan, which is pro- per for fir trees, and also at greater distances.
The preceding Tables VI. VII. and VIII. are calculated on a supposition that the trees are never suffered to stand nearer, on an average, than one-fourth of their height ; and although the quantities of timber thinned out and left stand- ing on the ground at that distance, at the end of 60 vears be only two-thirds of the quantity according to Mr. Sal- mon's distance, yet 1 suppose it will be generally thought an ample produce and sufficiently encouraging.
According to Table VI. which is calculated for oaks, the first thinning is at sixteen years old, and the second at twenty, but it is the advice of an eminent planter, (Mr.
Z 3 Pontey,)
338 Method of ascertaining the Value
Pontey,) to begin thinning at about thirteen years old, ac- cording to the state of the trees, and to cut out about 150 poles per acre annually, for the next seven years. Without putting any value upon the thinnings before 20 years old, we find that at the 20th and 24th years the thinnings mea- sure 945 feet, the value of which, at a low estimate, will be sufficient to repay the rent and taxes of ground of a mo- derate quality, the expense of plants, planting, and after- management, calculated at five percent, compound interest.
When 23 years old, and at the end or' every fourth year following, up to 120, the trees to be cut out of an acre will measure from 49-5 to 550 feet ; but say 500, at 4s. a foot, on an average, including the value of the bark ; this gives JOO/. which sum divided by 4, leaves 25/. for the produce per acre per annum. Tins deserves the consideration of those who. are inclined to convert young woods into coppices, without leaving a reasonable number of standards.
It may however be said, that as the trees cut out in thin- . ping plantations are the bad thrivers and underlings, their contents will be less than the average; but, if we take their value at one -half the above estimate, tliat is, after the rate of 12/. lbs. per acre per annum at 28 years of age and up- wards, even this produce must be thought ample, together with the value of the trees left standing.
Table VI. was constructed chiefly with a view to oaks, their annual increase in circumference varying from {- of arj jnch to \\ inch, the medium of which is one inch.
Tables VII. and VIII. were calculated for ash, elm, sy- camore, firs, poplars, and other woods of swift growth, their increase in circumference being generally from l£ to 2 inches annually. If ash trees be found to increase after the rates of Table VII. or VIII. they must be exceed^ ingly profitable, at the high prices now given for that timber. Many other observations might be made on Tables VII. and VIII., but these will readily occur to persons interested in quick-growing trees.
An acre of trees increasing after the rate of Table VI. produces in 64 years little more than half the number of feet
that
of Growing Timler Trees. 359
that another acre produces which increases after th& rate of Table VII., and little more than one-third of another, in- creasing after the rate of Table VIII. in the same time.
In planting with a view to profit, the first object is a long, straight, and clear stem. This is most certainly and speedily- obtained by thick planting at first, and not thinning too soon. A kind of competition among the trees is thereby occasioned, each struggling, as it were, to outgrow its neighr bour, in search of light, heat, air, and moisture.
This competition must, however, be judiciously mode- rated by timely thinning 5 always keeping the trees suffi- ciently strong in the stem. If they be suffered to stand some years too near each other, their stems will become weak, and bend under their small tops when thinned. Where this has taken place in only a small degree, they will make but little progress for some years afterwards.
By the time the trees have advanced to 24 or 30 feet high this competition should cease, if they are intended to be cut down at or before 60 years of age, and they should then be encouraged to extend their tops more in width than in height, strong side branches being apparently quite as con- ducive as the leading shoot, to the vigorous growth of the bole below them. After this period, the best rule for thinning will probably be, to leave a clear space around the top of each tree, in which the branches may extend themselves without obstruction. A tree whose top is 20 feet diameter, receives four times the benefit from air, rain, and dew, as another does whose top is only ten. feet diameter.
The trees in the interior of young woods are smaller in their boles than the exterior trees. And in a fine oak wood, of about 40 acres, divided into squares by several avenues or ridings crossing each other at right angles, I observed the rows of trees next the avenues much thicker in their boles than the trees in the interior of the squares ; owing, no doubt, to their having more and larger branches in conse- quence of their having more room, although it is only on one side.
Being too parsimonious of ground seems to me a great and very general error. If the same number of trees of 32
Z 4 feet
360 Method of ascertaining the Value
feet high and upwards, in Table VI. were allowed the space or two acres instead of one, and, in consequence of their standing thinner, were to increase annually only the fiftieth part of an inch more in girt than they would do if they stood on one acre, this small additional increase in girt would pay an ample rent for the additional acre.
In the year 1791 a paper of Observations on the Propa- gation and Management of Oak Trees in general, but more particularly applying to his majesty's New Forest in Hamp- shire, was published by T. Nichols, Purveyor pf the Navy for Portsmouth Dock-yard.
In this paper it is said, that t{ there are to be seen in many parts or' the forest from 40 to .50 fine oaks standing on an acre, that will measure one with another two loads a tree."
" Several woods in the forest are almost ruined for want of thinning, and its being done at proper times ; particularly the inclosures that were made in the year 1 700 : — these were originally well planted, and great numbers of trees brought up in them, which now remain so close together that they are nearly stagnated, particularly in Salisbury, Trench, Brimley Coppice, and Woodfidley ; and although it is 90 years since they were planted, the trees will not measure, one with another, above six or seven feet a tree ; whereas, if the business of thinning had been done as it ought, the remaining trees (after drawing much useful timber) would by this time have been of a size nearly fit for naval uses, as in sonae of the woods that were planted at the same time, the trees which have had room to expand, and a free air ad- mitted to them, will measure from 70 to 80 feet."
Observations on the Croivth of Timber \ The rings observable in the transverse section of a tree at its butt-end, are the same in number as the years of its age; an additional ring being produced annually, in consequence of the annual rising of the sap. The rings are nearly con- centric in trees that have grown in the interior of close shady woods, but eccentric in others, being of different breadths on the northern and southern sides of such as have grown
single.
of Growing Timber Trees. 36 L
single, or in any other situation where their holes have heen much exposed to the rays of the sun. This difference is oc- casioned by the different degrees of heat to which the oppo- site sides of the boles of trees are exposed. And, indeed, we find these rings are always broadest on that aide of the bole or stem most warmed by the sun. Hence we see the utility of exposing their boles as much as possible to its rays*. It is often seen in the stumps of trees that have stood single, that they have grown nearly twice as fast on the southern side as on the northern, their pith being so much nearer to the northern side.
It is, however, to be remarked, that the wood from that side of a tree which has grown the slowest, is heavier than from the opposite side which has grown the fastest, and it is probably stronger in the same degree.
It may be worth the consideration of those who have southern hangs or declivities to plant, whether to plant, or rather leave the trees in thinning, in double rows in lines running east and west, at about fourteen or sixteen feet di- stance, and the double rows at about thirty-six feet distance, less or more, according as the declivity is more or less, in order that their boles may receive the greatest possible benefit from the direct rays of the sun.
No doubt many gentlemen are in possession of facts that would in some degree ascertain how much faster the boles of trees swell that stand exposed to receive the full benefit of the warmth of the sun, than those that are either partially or •constantly in the shade. To make these facts known would materially benefit planters ; for I am fully persuaded that there are but few persons apprised of the magnitude of the power of the sun's rays upon the boles of trees in causing them to swell.
Of the most profitable Length of Boles of Trees, We rarely see timber trees pruned, and still more rarely
* On a hot day in the middle of May I have observed the mercury in the thermometer to rise and fall from twelve to sixteen degrees, on hanging it al- ternately in the sunny and shady sides of the same tree, between the hours of two and five o'clock, at which time of the day the heat is generally the greater.
362 Method of ascertaining the Value
do we see the pruning performed in a -judicious manner. This business should commence early, never suffering the branches on the intended stem or bole to grow to a large size, in order that, when cut off, the wounds may be small and soon healed. Those who want directions for performing the operation, may think it well to consult Mr. Pontey's Forest Pruner. There are, however, divers opinions as to the most profitable height to which trees ought to be pruned, and the instruments most proper for pruning ; some persons objecting to the use of the saw, unless afterwards smoothed by the knife ; and not a few objecting to pruning in any way ; the consequence of which is, that we often find trees that stand single, particularly oaks, with boles not more than six or eight feet high, but with wide spreading bushy tops, fit only for the fire. The shade and drip of one such tree \s sometimes found to do more injury than four well- trained trees, and perhaps it is not of half the value of one of them. On the contrary, trees in close plantations are often suffered to stand so much too thick as to destroy each others branches, excepting only a few small ones near their tops ; and not unfrequently we see tall elms trimmed up to within a few feet of their summits — it is certain that such trees must sweli very slowly in their boles ; for we find in woods where the trees are ail of the same age, that those with the largest tops have generally the thickest holes.
There is no doubt a medium length of bole for different kinds of trees on different soils, that will be found produc- tive of more timber, or timber of more value, than boles- that are much longer or much shorter. And although we may not be able previously to decide with certainty what that exact length of bole is, in any kind of trees, on any soil, which will eventually prove most profitable, yet it is deserving of investigation, if we can thereby approach with certainty to within a few feet of the exact point. It is cer- tainly a matter of too much importance to be left, as it ge- nerally is, to each individual woodman to decide upon, ac- cording to his own vague opinion. I shall, therefore, take the liberty of stating by what steps I have endeavoured to approximate towards the most profitable lengths of boles of
trees
of Growing Timber Trees. 383
trees of different rates of growth, that are not intended to stand beyond the age or sixty years.
In the preceding tables the trees are supposed to be mea- sured to the top of the leading shoot, but in the following tables only to the height of their boles of 24, 32, and 40 feet.
Tables showing the Increase of Boles of Trees of different Lengths, If a tree has increased twelve inches in height and one in circumference annually, until it is twenty-four years old, it will then be twentv-four feet high, and three inches girt at twelve feet high; and supposing that in process of time this tree be pruned up so as to leave the bole twenty- four feet high clear of branches, and that it continue increasing one jnch In circumference annually, the rate per cent, per annum of its increase will be as under, exclusive of the increase of timber in its top and lateral branches.
TABLE X.
|
Years |
Years] |
One Year's |
Increase |
||||||
|
old. |
Gin |
Contents. |
old. |
Girt. |
Contents. } Increase. |
pcr«Ccnt- |
|||
|
t |
per Ann. |
||||||||
|
in. |
ft. in. pt |
in. |
ft. |
in. pt. |
it. |
in. p |
|||
|
24 |
3 |
16 0 |
25 |
31 |
1 |
9 1 |
0 |
3 1 |
171 |
|
28 |
4 |
2 8 0 |
20 |
41 |
3 |
0 1 |
0 |
4 1 |
127 |
|
32 |
5 |
4 2 0 33 |
*i |
4 |
7 1 |
0 |
5 1 |
101 |
|
|
36 |
6 |
6 0 0 |
37 |
61 |
6 |
6 1 |
0 |
6 1 |
84 |
|
40 |
7 |
8 2 0 |
41 |
7k |
8 |
9 l |
0 |
7 1 |
7'2 |
|
44 |
8 |
10 8 0 |
45 |
81 |
11 |
4 1 |
0 |
8 1 |
63 |
|
48 |
9 |
13 6 0 |
49 |
9i |
14 |
3 1 |
0 |
9 1 |
5-6 |
|
52 |
10 |
Id 8 0 |
53 |
101 |
17 |
61 |
0 |
10 1 |
5-04 |
|
56 |
11 |
20 2 0 |
57 |
111 |
21 |
1 1 |
0 |
11 1 |
45 |
|
60 |
12 |
24 0 0 |
61 |
12; |
25 |
0 1 |
1 |
0 1 |
41 |
|
64 |
13 |
28 2 0 |
65 |
131 |
29 |
3 1 |
1 |
1 1 |
3-S |
|
63 |
14 |
32 8 0 |
69 |
141 |
33 |
10 1 |
1 |
2 1 |
35 |
|
72 15 |
37 6 0 |
?3 |
15. [ |
38 |
9 i |
1 |
3 1 |
3'3 |
|
|
76 j 16 |
42 8 0 |
77 |
10 |
44 |
0 1 |
1 |
4 1 |
31 |
|
|
80 17 |
48 2 0 |
81 |
'7v |
49 |
7 1 |
1 |
5 1 |
29 |
|
|
84 |
IS |
54 0 0 |
85 |
is.i |
55 |
6 l |
1 |
6 1 |
27 |
|
88 |
19 |
60 2 0 |
89 |
i9i |
61 |
9 1 |
1 |
7 l |
26 |
|
92 |
20 |
66 8 0 |
93 |
20; |
68 |
4 1 |
1 |
8 1 |
2'5 |
|
96 |
21 |
73 6 0 |
97 |
21 , |
73 |
3 1 |
1 |
9 1 |
23 |
|
100 22 |
80 8 0 |
101 |
22j |
82 |
6 1 |
1 |
10 1 |
22 |
|
|
120 2/ |
121 6 0 |
121 |
27, |
123 |
9 1 |
2 |
3 1 |
1-8 |
|
|
140 3 2 |
170 8 0 |
141 |
32', |
173 |
4 1 |
2 |
8 1 |
i'4 |
|
|
100 37 |
228 2 0 |
161 |
37] 231 |
3 1 |
3 |
1 1 |
.13 |
But
S6% Method of ascertaining the Value
But if a tree increase 12 inches in height and one inch in circumference annually, until it be 32 feet high, and in pro- cess of time the bole be pruned up to that height, the rate per cent, per annum of the increase of this bole will be as under, exclusive of the increase in its top and lateral branches. TABLE XI.
|
Years |
Years |
On< |
J Year's |
Increase |
||||||
|
old. |
Girt. |
Contents. |
old. |
Girt. |
Contents. |
Increase. |
per Cent. |
|||
|
per Ann. |
||||||||||
|
inch. |
ft. |
in. pt. |
inch |
ft. in. pt. |
it. |
in. |
pt. |
|||
|
32 |
4 |
3 |
6 8 |
33 |
** |
4 0 2 |
O |
5 |
6 |
12*p |
|
36 |
5 |
5 |
6 8 |
37 |
H |
6 1 6 |
0 |
6 |
10 |
1025 |
|
40 |
6 |
8 |
0 0 |
41 |
6| |
8 8 2 |
0 |
8 |
2 |
8 5 |
|
44 |
7 |
10 |
10 8 |
45 |
1\ |
118 2 |
0 |
9 |
6 |
7'3 |
|
48 |
8 |
14 |
2 8 |
49 |
b] |
15 1 6 |
0 |
10 |
10 |
63 |
|
52 |
9 |
J8 |
0 0 |
53 |
p! |
19 0 2 |
I |
0 |
2 |
56 |
|
56 |
10 |
22 |
2 8 |
57 |
*<H |
23 4 2 |
I |
1 |
6 |
5'06 |
|
60 |
n |
26 |
10 8 |
61 |
m |
28 1 6 |
1 |
2 |
10 |
459 |
|
64 |
12 |
32 |
0 0 |
65 |
121 |
33 4 2 |
1 |
4 |
2 |
4-2 |
|
68 |
13 |
37 |
6 8 |
69 |
131 |
39 0 2 |
1 |
5 |
6 |
3-88 |
|
72 |
14 |
43 |
6 8 |
73 |
141 |
45 1 6 |
1 |
6 |
10 |
3-6 |
|
76 |
J5 |
50 |
0 0 |
77 |
)-H |
51 8 2 |
1 |
8 |
2 |
3'36 |
|
60 16 |
56 |
10 8 |
81 |
tfi |
58 8 2 |
1 |
9 |
6 |
3-1 |
|
|
100 J 21 |
98 |
0 0,101 |
2H |
100 4 2 |
2 |
4 |
2 |
239 |
||
|
120 ! |
26 |
150 |
2 8[ |
121 |
26i |
153 1 5 |
2 |
10 |
9 |
1*92 |
But if a tree increase 12 inches in height and one inch in circumference annually, until it be 40 feet high, and in process of time the bole be pruned up to that height, the rate per cent, per annum of the increase of this bole will be as under, exclusive of the increase in its top and lateral branches.
TABLE XII.
|
Years- |
Years |
One Year'.^ |
Increase |
||||||||
|
old. |
Girt. |
Contents. |
old. |
Girt. |
Contents. |
Increase. |
per Cent. |
||||
|
per Ann. |
|||||||||||
|
incn. |
ft. |
in. pt. |
inch. |
ft. |
in. |
Pt. |
ft. in. |
pt |
|||
|
40 |
5 |
6 |
11 4 |
41 |
« |
7 |
7 |
10 |
0 8 |
6 |
102 |
|
44 |
6 |
10 |
0 0 |
45 |
0$ |
10 |
10 |
2 |
0 10 |
2 |
8-47 |
|
43 |
7 |
13 |
7 4 |
49 |
A |
14 |
7 |
2 |
0 11 |
10 |
7*2 |
|
52 |
8 |
17 |
9 4 |
53 |
8| |
18 |
10 |
10 |
1 I |
6 |
6-3 |
|
56 |
9 |
22 |
6 0 |
57 |
91 |
23 |
9 |
2 |
1 3 |
2 |
56 |
|
60 |
10 |
27 |
9 4 |
61 |
10{ |
29 |
2 |
2 |
I 4 |
10 |
505 |
|
64 |
11 |
33 |
7 4 |
65 |
M |
35 |
1 |
10 |
1 6 |
6 |
4-58 |
|
68 12 |
40 |
0 0 |
69 |
J 2* |
41 |
8 |
2 |
1 8 |
2 |
42 |
|
|
72 13 |
46 |
11 4 |
73 |
*W |
48 |
9 |
2 |
l 9 |
10 |
3 87 |
|
|
76 14 |
54 |
5 4 |
77 |
14! |
56 |
4 |
10 |
1 11 |
6 |
3'59 |
|
|
80 15 |
62 |
6 0 |
81 |
15' |
64 |
7 |
2 |
2 1 |
2 |
335 |
|
|
100 I 20 |
111 |
1 4 |
10! 20, |
113 |
10 |
10 |
2 9 |
6 |
251 |
||
|
120 : 25 |
173 |
7 4 |
121 I 25 J |
177 |
1 |
2 |
3 5 |
10 |
2 00 |
Observations
of Growing Timber Trees. 36*5
Observations respecting Trees of different Lengths in the Bole. Trees that increase annually 12 inches in height and one in circumference, and have boles of different lengths, these boles, if of the under-mentioned lengths, increase after the rate of five per cent, per annum at the ages and heights un- der mentioned, and ihey measure as under, viz.
Contents.
Years old. In. Ft. Ft. in. p.
Trees with 12 feet boles at 46 their crirt 10 at 6 high, 8 4 0
Do. 16 do. 43 do". 10 ;>t 8 do. 11 1 4
Do. 94 do. 52 do. 10 at 12 do. 16 8 0
Do. S3 do. 56 do. 10 at IS do. 22 2 8 t
Do. 40 do. 60 do. 10 at 20 do. 27 9 4
Do. 48 do. 61 do. 10 at 24 do. 32 4 O
Whatever the lengths of the boles of trees increasing as above maybe, the increase is 5 per cent, per annum one year after their girt in the middle is ten inches, but not longer.
But supposing that these trees have grown to 60 years of age, and increased as above mentioned, their girt and con- tents at that age would be as under, viz.
Contents.
Ft. in. p. '
Trees with 16 feet holes, 13 inches girt at 8 feet high, 18 9 4
Do. 20 do. 12$ do, 10 do. 21 8 5
Do. 24 do. 12 do. 12 do. 24 O 4
Do. 32 do. 11 do. 16 do. 26 10 8
Do. 40 do. 10 do. 20 do. 27 9 4
This table shows that the advantage to be gained by prun- ing trees higher than 32 feet, is not an object worthy of consideration, if the trees are to be cut down at the age of 60 years.
And if it should be found that the higher a tree is pruned the slower it swells in the bole, perhaps a 24 feet bole may measure as much at 60 years old as a 32 feet bole. If it increases half an inch in girt in the last 36 years more than the 32 feet bole increases in th$ same time, it will very nearly equal it in measure.
A 32 feet bole with a top from 20 to 30 feet high, with many large lateral branches, is certainly a much finer object than a forty feet bole with a top only twenty feet high, with few and small lateral branches : and at sixty years old, the former will have had to increase in the last twenty-eight years, only one quarter of an inch in girt, more than the
latter,
366 Method of ascertaining the Value
latter, to exceed it in measure, to say nothing of the excess of timber in the larger lop and branches. It must, however, be remarked, that at eighty years of age, the forty feet bole will exceed the thirty-two feet bole nearly six feet; and at one hundred years, thirteen feet, provided it swell equally fast in thickness. But unless the trees be oak, fit for the •use of the navy, for which an increased price can be had, I imagine few gentlemen would now choose to let their trees stand to eighty years of age, when the increase of their boles will not be four per cent. ; still fewer would let them stand to one hundred, when the increase will not be three percent, per annum.
|
Contents. |
||
|
Ft. |
in. |
pi. |
|
52 |
9 |
9 |
|
CI |
0 |
5 |
|
67 |
6 |
0 |
|
15 |
7 |
6 |
|
78 |
1 |
S |
|
increase |
Again, let it be supposed that trees sixty years of age have increased annually, during their growth, fifteen inches in height, and one inch and a half in circumference, the girt and contents of their boles, if of the under-mentioned lengths, will be as under, viz.
Trees with 20 feet boles, will be 19} inches girt at 10 feet high, Do. 25 do. IS] do. I2>- do.
Do. 30 do. IS do. 15 do.
Do. 40 do. 1$| do. 20 do.
Do. 50 do. 15 do. 25 do.
Taking it for granted that the shorter boles will faster in thickness than the longer ones, it is reasonable to expect that the forty feet bole will contain more timber than the fifty feet bole when they are both sixty years old ; and if they are both sold at the same rate per foot, the forty feet bole must consequently be more valuable. If, however, a higher price can be had for longer boles, this may com- pensate not only for their deficiency in measure at sixty years of age, but also for their standing beyond the period when they cease paying the common rate of interest for the money they are worth, which I suppose is frequently the case as to tall elm trees, fit for keel pieces, and perhaps beech for ship planking. It is hence evident, that where the soil is such as will enable trees to grow to a great height, it will be necessarv, before we decide how high to prune them, to consider to what purposes the timber can be most advantageously appropriated.
S Whatever
of Growing Timber Trees, 36*7
Whatever the lengths of the boles of trees increasing as above may be, their increase is five per cent, per annum, one year after their girt in the middle is 15 inches, but not longer.
Again, let it be supposed that trees sixty years of age have increased annually, during their growth, eighteen inches in height, and two inches in circumference, the girt and contents of their boles, if of the under-mentioned lengths, will be as under, viz.
Contents.
Ft. In. pt.
Trees with 24 feet boles, will be 26 inches girt at 12 feet high, 1 12 8 O
Do. SO do. 25 do. 15 do. 130 2 6 '
Do. 36 do. 24 do. J 8 do. 144 O 0
Do. 48 do. 22 do. 24 do. 161 4 0
Do. 60 do. 20 do. 80 do. 166 8 0
Here again we may suppose that the forty- eight fret bole, by swelling faster than the sixty feet bole, may exceed it in measure at sixty years of age, and this it would do, were the girt increased only half an inch. And if the thirty-six feet bole was increased two inches in girt, it would exceed both the forty- eight and sixty feet boles. But trees of such swift growth are frequently cut down before they are sixty years old. At forty years of age the thirty-six feet bole, if it swell no faster than the forty-eight feet bole, will contain more timber if measured according to the present erroneous method. (The greater disproportion there is between the two ends of a piece of timber, and the more disadvanta- geously it measures, when the girt is taken in the middle.) I suppose that in timber of this swift growth, the longer boles are frequently not worth more per foot than the shorter boles; therefore, in this case, that length of bole should be. fixed on which is likely to measure most at the period when, the trees are intended to be felled.
Whatever the lengths of the boles of trees increasing as above may be, their increase is five per cent, per annum, one year after their girt in the middle is 20 inches, but not longer.
It appears from the last observations and calculation?, that the annual increase in the boles of trees by their growth, ceases to be equal to five per cent, pet annum some time
between
36S Method of ascertaining the Value
between forty-six and sixty years of age> according as (be- boles are shorter or longer.
But it being generally allowed that oak trees, of a size fit for the navy, require to grow from eighty to one hundred and fifty years, according to the quality of the soil, and it is so stated in the eleventh report of the commissioners ap- pointed to inquire into the state and condition of the woods, forests, and land revenues of the crown ; I have therefore been calculating tables, showing what the proportionably advanced prices should be, at different periods, up to one hundred and fifty years, to pay the proprietors for letting their trees stand to those periods. These prices, especially at the later periods, very greatly exceed any that have ever been given. It certainly has been much the interest of the growers of oak timber to fell it at about sixty years of age, even if they replant the same ground. To let it stand to one hundred and twenty years of age, and sell it at the present prices, their loss would exceed double the whole value of the timber at sixty years of age. Nothing short of a suf- ficient price will long command a sufficient supply. Owing to too low prices, the quantity of large timber on private estates has long been rapidly decreasing ; and it will be too late to commence offering reasonable prices for it when it is all gone, and no oaks left of greater growth than sixty years. To have to wait their growing the second sixty years, may bring upon us evils exceeding all calculation.
Valuations made in Oct<-her, 1807, of several Plantations in Staffordshire.
The valuations were made of the trees growing within the space of a chain square, being the tenth part of an acre, of the medium growth of each plantation.
In the plantation by the mill wall there are now growing within twenty-two yards square, as under, viz.
£. s. d. £. s. <?.
70 oak trees, containing 175
feet, at 3*. 3d. 19 13 9
1 200 of oak bark, at 1 L2s. 7 4 0
'20 17 9 or, per acre, 268 17 0
The
of Growing Tbnler Trees 4 369
The above is part of about four acres planted in 1775, on a strong loamy soil, worth about 205. an acre. One pound per annum forborne 32 years, and improved at five
percent, compound interest, would amount to "ihl. 6s. But the value of the timber is more than three times this amount.
The ground was prepared for planting by ploughing.
On the east side of Cottage Wood there are now growing,
within twenty-two yards square, as under* viz.
£. 5. d< &i s. d,
50 ashes, containing 300 feet,
at is. 6d. - - - 22 10 0
13 oaks do. 7 do. 25. 0 14 0
Bark - - - o 7 0
23 1 1 0 or, per acre, 235 10 O
The above is part of about two acres planted in 1776, partly on heaps of earth in clay pits, and partly on strong soil upon a deep bed of sand, value about 155. an acre. Fifteen shillings per annum, forborne 31 years, and im- proved at five per cent, compound interest, would amount to - - 53/. 05. Od.
But the value of the timber is more than four times this amount.
In the clay pits only holes were dug for the plants, but the other part wholly trenched, or double dug with the spade.
In Pickmore Pool plantation there are now growing within twenty- two yards square, as under, viz. 97 Scotch firs, containing 636 feet*, at 15. — 31/. 165. Od.
or, per acre, 318/. 05. Od.
The last plantation is part of about six acres planted in the springs of 1778 and-9. Much of the soil is a tough peat on gravel or hungry white sand, worth, say 5s. per acre.
This ground lay between two tenants who had never cul- tivated it. They had then nineteen years unexpired of their
» This produce is after the rate of 6V>60 feet an acre, which is about the rateofTufilelV.
Vol. 33. No. 133. May 1809. A a lease
3*0 Method of ascertaining the Value
lease of thirty-one years of tins and the adjoining lands, and willingly gave it up to be planted, on condition of having the fences made and kept in good repair! Five shillings a year, forborne 29 years, and improved at five percent, compound interest, would amount to 15/. 1 Is. od. But the value of the timber is more than twenty times this amount.
The trees were about two feet high, and planted at two yards distance, in holes dug with the spade, 1210 on an acre. Labour of making the holes and planting the trees cost \l. 6s. \0±d. per acre.
About 2700 were planted on an acre in the other planta- tions, where the ground was wholly broken up.
In the remarks on these three plantations, no notice is taken of the thinnings. I am informed by gentlemen who have kept accounts of thinnings, that these have repaid the rent of the land and every expense, with compound interest, 6ome time before the woods were thirty years old; and the preceding calculations show that it may be so. And if so, the present value of these plantations is all clear gain.
The valuer of these plantations has bought a good deal of wood out of them ; and. the prices he has valued at per foot, may possibly be a fair value there for such small timber.
The growth of the firs in the last- mentioned plantation, is probably as great in that poor ground as it would have been had they been planted on ground of three or four times its value; this must be a powerful inducement to gentlemen to plant all such poor ground in the first instance.
And a few of oaks, ashes, and firs, may be raised on al- most every farm in screens, that may, by their shelter, in- crease the value of the farm to the occupier, by increasing the produce, particularly that of grass grounds. In this case the interest of landlord and tenant may be reciprocal ; but it is the reverse where trees are planted in hedge-rows.
And even the sides and tops of high mountains may be made abundantly more productive of grass, if certain por- tions of them were surrounded by plantations. These planta- tions, by breaking the force of cold winds, diminish their chilling effect on the fields the plantations surround, and
render
of Growing Timber Trees. 371
render the climate on mountains much more mild and genial.
This last kind of improvement will generally be found very greatly to exceed the expectation of the improver, pro- vided it be judiciously planned and executed,
May I take the liberty to suggest, that information of very great value might be obtained by the Society from the gentlemen to whom medals and premiums have been given for planting trees, if they would favour the Society with their subsequent observations respecting those plantations.
It would, for instance, be desirable to have the nature of the soil and under strata described, — the sorts of trees best suited thereto, — the distance at which the trees v\ere first planted, — at what periods they were thinned, and how many cut out at each thinning, and their measure and value, — the present height, distance, measure, and value, of the trees now growing on an acre, — what distances are found most advantageous, and also the best height to be pruned.
The fund of information that such communications plight afford, would prove of very great value indeed to future planters, as well as to many proprietors of plantations of different ages now growing.
If the Society should think it advisable to solicit this in- formation, no doubt the ample and valuable materials they would thereby obtain, would enable some abler pen to do justice to the curious and important subjects of the preceding pages. In the mean time it is hoped, that this attempt to reduce our knowledge of the growth of timber to something like system, however imperfect it may be, will be received with indulgence. Assuredly, it had not so soon seen the light, had not the present situation of our country impe- riously demanded of every individual his utmost exertion to render us as independent as possible of supplies of every kind from the continent of Europe, from which we are now almost totally excluded.
C. Waistell.
High Holborn, March 15, 1808.
To Charles Taylor, M.D. Sec.
A a 2 ' LXVI. On
[ 372 ]
LXVJ. On the intended Thames Archway letween Rothcr- hithe and Lime/iouse. By Mr. John Farey, Mineralo- gical Surveyor.
To Mr. Til loch, — Sir, In an age like the present, when the abilities of a Renniey a Jessop, a Telford, and numerous other British civil en- gineers are so universally known, by the great works which have been executed within the last 30 years under their di- rection, wherein difficulties of almost every kind have been successfully overcome, and tunnels in the most difficult situations have been constructed, in considerable numbers : it must excite surprise in every one to learn, that after more than three years have been spent by a company of proprie- tors in the metropolis of the country, in ineffectual attempts towards constructing a dry tunnel for a road-way under the bed of the river Thames, as a substitute for a bridge, that the directors appointed by these proprietors should now be advertising (in the newspapers, and by a printed hand-bill, which is given below,) for the schemes of inexperienced adventurers, rather than call in the professional aid of one or ino/e of the established engineers of the country, to the effecting of the purposes which they have in view. Surely it cannot be expected by these gentlemen, that any of the ex- perienced engineers alluded to, will submit their designs and estimates for the great work which the proprietors have un- dertaken, on the terms and for the considerations held out ; — who is to decide on the merits of the different designs which may be delivered in? and who is to superintend and execute the design which maybe adopted? On both of these questions, the probability either of honour or profit to be derived from their labours, will in all likelihood turn, according to the conditions which the directors have laid down.
In your Magazine, No. 97, for June 1806, (vol.xxv. p. 4 6,) I gave a hasty sketch of the state of the works at that time, and an account, extracted from Mr. Robert Vazie's books, of the strata expected by him to be met with in sinking the shafts on the south and north shores, and in driving under
the
On the intended Thames Archway* 373
the river between these shafts : at that time Mr. V. was very confident in considering the strata as regular and undisturbed which his borings had penetrated, notwithstanding my opinion expressed to him on seeing the specimens, that the whole were alluvial, and their continuance horizontally not in the least to be depended on, as mentioned at page 49 of my paper in your Magazine, of which he had three or four copies from me at his request, to distribute among the di- rectors of the concern. The following accounts, which the directors have lately published, show, after more than two years of very expensive trial, that these ideas of mine have been confirmed, as they might have been in a few weeks time, by the borings in the bottom of the river which I recom- mended, first in Dr. Rees's New Cyclopaedia (sect. Thames* in the article Canal), and again in my paper in your Maga- zine above referred to ; and such borings would doubtless have suggested the conclusion, without all this loss of money and time, which the engineer (Ouere, was it Mr. V. or Mr. T. ?) at length came to, viz. : " That an underground tunnel could not be made in that line, unless the fractures were covered by caissons, without which the further pro- gress of the drift would be useless ;" but he continues, " that he had no doubt of being able to make a tunnel over the same line through the river, sufficiently deep into its bed, by means of movable caissons, or coffer-dams, and at a less expense considerably than the original estimate for the un- derground plan: and without any impediment to the naviga- tion of the river." From the expressions of the directors which follow, it is too much to be feared, that the counsels which first prevailed in adopting a deep underground tunnel, rather than one laid as near as may be to the bottom of the water in the river, has still a prevailing influence among them; in which case I venture again to predict, that the expectations of the proprietors and the public, will be ulti- mately and grievously disappointed.
At the time of writing the short notice of this under- taking, in connection with the navigation of the Thames river, for the Cyclopaedia, I was too much hurried to give the subject that consideration, which its obvious importance
A a 3 has
374 On the intended Thames Archway
has since occasioned it to have, particularly when I have been in the company of ingenious and practical men in such matters, and have introduced the subject, in order to hear the ideas of others relating to it. Instead of piling ojf the river, as I there hastily mentioned, I would suggest to the consideration of those engineers who may turn their atten- tion to the subject, an immense tub in form of the frustum of a cone, secured by hoops outside, and polygonal framing inside, but without either bottom or top, which being prin- cipally of wood, might be floated at high water to the spot where the tunnel is to be begun ; the bottom edge of it might be so secured to the bottom of the river, by means which will suggest themselves to competent engineers, as to prevent the influx of water from the river, or the pressing in of quick-sand or silt, after the water is extracted from the tub bv engines ; and after a length, of 70 or 80 feet per- haps, of the tunnel was constructed, its end might be so se- cured as to admit of moving the tub, to include a new length ; with scarcely any interruption to the navigation of the river. I have often been sanguine enough, to expect to see se- veral tunnels constructed under the Thames and other of our important navigable rivers, in some instances, super- seding, perhaps, the ancient bridges like that of London ; but must confess, that the origin and proceedings of the two Thames Archway Companies, which we have seen, and particularly the proposals by the directors of one of them, which follow, have occasioned me to doubt much, whether I shall live long enough, to pass through a tunnel con- structed, under their auspices, unless indeed a material change takes place in their principle of proceeding.
I am, sir; your obedient servant,
John Farey.
Westminster, May 12, 1809.
Particulars of the strata met with, in sinking a shaft near the Horse-Ferry in Rotherhilhe, and in driving a heading thence under the bed of the Thames river, 1035f feet in length, intended as a drain for the proposed road arch- way : with an account of the progress and present state of
the
lei ween Rot her hit he and Limchouse. 375
the works, and of two premiums advertised by the direc- tors for plans, according to which the tunnel may be constructed.
The Thames Archway Company was established by an act of parliament (45 Geo. III.) "for the purpose of form- ing a tunnel under the river Thames, either for foot passen- gers or carriages, or for both ;" and by the unanimous opi- nion of every engineer who had been consulted, it w?s deemed necessary, as a preparatory step, to make a drift- way to extend as far as the deepest part of the river; and ac- cording to the original plan of this undertaking it was in- tended then to begin to construct the tunnel, carrying it forward in both directions from<the centre to the north and south sides of the river : a shaft was therefore sunk on the south side near the Horse-ferry, RedrifTe, and a drift- way made to the point first proposed. It was, however, then determined to continue the drift to the opposite shore, in the line and direction of the proposed tunnel, for the sake, amongst other reasons, of exploring the ground through which that part of the tunnel was intended to pass ; and thereby enabling the engineer to anticipate and guard against difficulties.
In pursuance of this determination the drift- way was carried on to the extent shown in the accompanying plan, at A, when the engineer proposed another mode of executing the tunnel, and, in his opinion, much less difficult and less expensive, and for which the further extension of the drift would be useless; the directors, being convinced that there are many methods of accomplishing the object, and that it is their duty to procure the best in their power, thought proper, before this or any plan were adopted, to suspend the works, and to invite ingenious men of every description to a consideration of the best means of completing so useful and so novel an undertaking.
With this view the directors are induced to offer the fol- lowing premiums, namely,
Tivo hundred pounds to the person whose plan shall be adopted and acted upon 5 and a further sum of three hundred pounds if it be executed.
A a 4 The
376 On the intended Thames Archway
The first premium to be paid within three months after the plan shall have been put iu execution. The second premium within three months after the tunnel shall have been opened for passengers.
The plans to be accompanied with full and clear specifi- cations and directions how to carry them into execution, and an estimate of the expense. They must be signed by fictitious names, -mottoes, or marks, and will be returned if not adopted to any person claiming them under the fictitious name, motto, or mark ; the real name to be enclosed in a sealed note, and externally marked with the fictitious name, &c; which note shall not be opened unless it be that of the person whose plan shall be adjudged entitled to the premium.
All the plans will be submitted to the judgement of emi- nent and competent persons chosen by the directors, who shall not be either proprietors or competitors ; so that every person offering plans may rely upon the fairness and impar- tiality of the decision.
The plans must be delivered at the office of Mr. Wadeson, in Austin Friars, London, solicitor to this concern, on or before the first of June next.
To enable engineers and others to form correct opinions on the subject, the directors have caused the following ac- count of such facts as were noted to have- occurred in the progress of the undertaking, to be extracted from the en- gineer's journal, which is accompanied by an engraving showing the plan and section of the works as far as they have proceeded.
Fig. l, (PI. XT.) is the section of the river, shaft, and ^drift-w iy, B the shaft on the south shore lined with nine- jnch brick-work laid in cement impervious to water. The strata through which it passed consisted of,
Ft. In.
1 . Brown clay 9 0
2. Loose gravel with a large quantity of water 26 8
3. Blue alluvial earth inclining to clay ...... 3 0
4 . Loam 5 1
5. Blue alluvial earth inclining to clay, mixed
with shells ....................... 3 9
0, CaL-
Ictween Rotherhithe and Limehouse. 377
Ft. In. Ft. In.
6. Calcareous rock in which are imbedded
gravel stones, and so hard as to resist the pick-axe, and to be broken only by wedges 7 6
7. Light coloured muddy shale, in which
were imbedded pyrites and calcareous
stones 4 6
8. Green sand with gravel and a little water 0 6 g. Green sand 8 4
68 4
From the surface of the ground to high water
marjk , 8 O
Depth of the shaft from high water mark 76 4
The gravelly stratum No. 2, in the shaft extends about 400 feet into the river from high water mark at T to V; at this latter place it is about two feet thick, and underneath is alluvial earth approaching the nature of clay.
The framing of the drift consists of three-inch plank, five feet high, three feet wide at bottom, and two feet six inches at the top inside.
Fig. 2 is a plan of the drift-way and shaft. In proceeding with the drift-way from the south to the north shore, the strata were constantly varying at the face of the drift as noted at the following places specified. The variations in the intermediate spaces were not noted. Face of the drift at the entrance from the shaft, measuring from the bot- tom upwards, Ft. In. Ft. In.
Green sand , 4 6
Gravel , 0 6
. — t* 5 Q At 177 feet from the shaft,
Green sand 4 0
Gravel ,...() 6
Blue muddy shale ...... O 6
5 O
A.t 234 feet, Green sand , 3 9
Gravel 0 3
J31ue muddy shale l o
« 5 O
M
378 On the intended Thames ArchiVay
Ft. In. Ft. In.
At 295 feet, Green sand 3 7
Gravel 0 3
Blue muddy shale ...... 1 2
5 0
At 31 7 feet, Green sand 3 5
Gravel o 4
Blue muddy shale ...... 1 3
5 0
At 321 feet, Green sand 3 3
Gravel O 4
Blue muddy shale ..... 1 5
5 0
At 333 feet, Green sand 3 3
Gravel 0 4
Blue muddy shale 1 5
5 0
At 350 feet, Green sand 2 8
Gravel 0 4
Blue muddy shale 2 O
5 0
At 493 feet, the green sand ends.
At 730 feet, Hard calcareous rock, mixed
with loamy sand 5 0
At 799 feet, Hard rock 5 0
At 858 feet, Ditto 5 0
At 901 feet, Ditto 5 0
At 931 feet, Rock, with a little sand and shells, and water in
the roof 5 O
At 945 feet, Hard rock 2 6
Clay -and shells 2 6
r 5 0
At 966 feet, Rock 0 3
Clay 0 4
Shells 2 0
Clay 1 0
Cockle shells 0 4
Clavs and shells 1 0
Sand 0 2
Clay 0 6
Sand 0 5
6 0
At 972 feet, Clav and shells 4 0
Sand 1 0
5 0
At
letween Rotherhithe and Limehouse. 379
At 992 feet, Clay and shells ....... O 8
Sand 4 4
5 0
At 1011 feet, Sand 3 6
Clay 1 6
5 O
The quantity of water in the gravelly stratum No. 2 of the shaft, was so considerable, that a fourteen-horse engine could only keep the water a few feet below its natural level, and the shaft was sunk through, by far the greatest part of this stratum, into the blue stratum No. 3, with the water standing in it to the depth of several feet. It is well ascer- tained that this stratum of gravel extends through a consi- derable part of the adjoining country; but borings being made in the shaft from the bottom of this stratum, no wa- ter was met with in the sub-strata to the depth of eighty-six feet from high water, where a spring was discovered, which rose in a few hours, through pipes inserted for that purpose, to a higher level than that in the gravelly stratum No. 2, The shaft was therefore sunk only to the depth of seventy-six feet four inches.
The drift was then carried forward in a horizontal direc* tion to the north, five hundred and fifty-nine feet. And, in order to explore the ground in the northern part of the line of the then proposed tunnel, the drift was turned to the west twenty-three feet six inches from the centre of the former line to the centre of the new direction, and then to the north, as shown in Fig. 2, (intended to be enlarged af- terwards to the size of the tunnel) and carried forward three hundred and forty-one feet, making the distance from the shaft to the beginning of the rise at D nine hundred and twenty-two feet. Through the whole, of this line no ma- terial interruption occurred ; the strata, as shown above, consisted of firm sand, calcareous rock, and concreted tra- vel, with no more water than was easily kept under by a fourteen-hovse engine.
At the point D the drift was made to incline upwards at the rate of one foot in nine. In prosecuting this part of the drift, at the distance of. twenty-three feet from the begin- ning of the incline, the earth in the roof broke down, and
discharged
380 On the intended Thaincs Archway
discharged a great quantity of sand and water into the drift. At the time this circumstance happened, a space of only six inches by thirty of earth in the roof and none in the face was left untimbered; and through this space the earth kept falling by degrees, until a hole was formed capable of letting a man stand up in it ; who observed a quicksand, about three feet thick, and about four or five feet above the roof of the drift. The stratum between the drift and sand was clay ; water flowed from the sand. The hole was after some difficulties filled up, and the works proceeded.
From the observations which had been made in the pro- gress of the drift, the engineer found that the strata dipped slightly from the south to the north, and concluded that the gravelly stratum No. 2 in the shaft would end in quicksand. This inference was confirmed by borings in the north siifre at E, and by the fact that the wells there are much deeper than on the south. In expectation therefore of drawing off the water from the face of the work, borings were made at D, through the roof of the drift, and pipes forced up to the top of the quick-sand, which had the desired effect. The water came free from sand for a considerable time; but when the sand began to come through any of the pipes they were plugged up, and others occasionally inserted in diffe- rent places to the south of these, with the same object in view ; and which kept the face of the work dry. By this means, and by using the utmost precaution in all other re- spects, the drift was afterwards extended seventy feet be- yond this fracture; where the roof broke down a second time, and sand and water entered the drift-way with great violence, and to an alarming degree ; so that in about a quarter of an hour the water rose in the shaft nearly to the top of it. On examining the river an opening or hole at w was discovered in the bed, of about four feet diameter and pine feet deep, and its sides nearly perpendicular. Into this hole, clay partly in bags, and other materials, were thrown sufficient to fill it up ; and which succeeded in stopping the communication between the river and the drift. The face pf the drift was again opened; but the men could make but little progress, as the water and sand frequently burst in
Vi.pon,
lelwecn Rotherhitfie and Limehousc. 381
upon them, and drove them away. Pipes were again put up at G, and the drift was extended twenty feet six inches further, in nearly a horizontal direction, through the quick- sand. The face was then timbered up, to prevent any further fall of earth or sand ; and a pipe nine feet long forced upwards diagonally at the face of the drift. The first eight feet through which this pipe passed was blue clay, and the last foot quicksand, of which a considerable quantity im- mediately flowed into the drift. This pipe soon became clogged up, it is presumed with clay, as some lumps came through nearly as large as the diameter of the pipe. An- other pipe, eight feet six inches long, was inserted hori- zontally in the face, and discovered nothing but blue clay : no sand nor water came through it.
At this period the engineer reported, that he had ex- amined the bed of the river, and found the hole at w con- siderably increased both in width and depth, and the earth at x very much sunk ; and that he had no doubt these two fractures communicated underneath. He then gave it as his opinion that an underground tunnel could not be made in that line, unless the fractures were covered by caissons, without which the further progress of the drift would be useless ; but that he had no doubt of being able to make a tunnel over the same line through the river, sufficiently deep into its bed, by means of moveable caissons, or coffer- dams, and at a less expense considerably than the original estimate for the underground plan ; and without any impe- diment to the navigation of the river. Under these circum- stances the further progress of the works was suspended. But the directors think it necessary to state, that although the engineer then in the Company's service was of opinion that an underground plan could not be executed in or very near the proposed line, yet there are others of a contrary sentiment; and notwithstanding the directors are in posses- sion of designs or plans (which may be inspected on appli- cation at the clerk's office in Austin Friars) for completing the undertaking, yet wishing to avail themselves of ail the ability of their country, in an undertaking of such novelty and importance, it becomes their duty to await the event of
this
382 On the intended Thames Archway ',
this address to the public, before any plan be adopted, however considerable its merits, or however eminent its authors.
In the design of any plan for this concern, engineers will doubtles pay particular attention to the difficulties which are likely to occur, from the situation of the quicksands, the communication with them and the river, and the falls in the bed of the river. And that they will not consider themselves as prevented from offering plans for executing the tunnel through the river itself, by means of caissons, coffer-dams, or any other method (if such method appear to them pre- ferable to the underground mode), provided in the execution of such plans no impediment be occasioned to the navigation of the river.
It is necessary to state, that any alteration in the line of the tunnel can be but inconsiderable, as it must be confined within the limits of the ground laid down in the accom- panying plan. *
It is an important consideration with the Company, that the size of the tunnel be large enough to admit two car- riages to pass each other 5 or two of smaller dimensions, each to admit a carriage.
The Company contemplate a foot tunnel, only in the event that a larger one should appear to be impracticable.
The plans must be formed with regard to the tunnel being lighted.
N.B. That plan whose line is the shortest, and ascent the easiest, will have great claims to preference, if equal in merit in other respects.
Reference to the Plate,
Fig. 1, (PlateXL) section of the river and works. Fig. 2, plan of the same.
B the shaft. A B the drift- way, as far as it has been ex- ecuted. The dotted lines De and EF, Fig. 1, show the proposed ascent and opening of the tunnel. The dotted lines in the plan, Fig. 2, show the proposed direction of the tunnel. The width of the river at low water is 619 feet, at high water 850 feet. The distance between the drift- way
On the Fibres used in Micrometers, &c. 323
way and the bottom of the river between D and E is no where less than 28 feet, and from D to A no where 1cj» than 25 feet.
The parts shaded in plan Fig. 2 are buildings.
LXVII. On the Fibres used in Micrometers: With an Account of a Method of removing the Error arising from the hl- flect ion of Light, by employing Hollow Fibres of Glass, By David Brewster, LL. D., Fellow of the Royal Society of Edinburgh, and of the Society of the Anti- quaries of Scotland.
H
DEAR SIR,
aving directed my attention for some years to the con- struction of micrometers, I have had frequently occasion to regret the difficulty of procuring fibres sufficiently fine and elastic for these delicate instruments. The impossibility of obtaining silver wire of a diameter small enough for this purpose, has induced Mr. Troughton to use the web of the spider, which he has found so fine, opaque, and elastic, as to answer all the objects of practical astronomy. I am in- formed, however, by this celebrated artist, that it is only the stretcher or the long line which supports the spider's web, that possesses these valuable properties. The other parts of the web, though equally fine and elastic, are very transparent, and therefore completely unfit for micrornetri- cal fibres. The difficulty of procuring the proper part of the spider's web, has compelled many opticians and practical astronomers to employ the raw fibres of un wrought silk, or, what is much worse, the coarse silver wire which is manu- factured in this country. But whatever be the relative ad- vantages of these different substances, they are all liable to the error arising; from the inflection of light, which renders it impossible to ascertain the exact contact between the fibre and the luminous body. This disadvantage lias been ex- perienced by every astronomical observer, and has always been considered as inseparable from the wire micrometer. I have, however, succeeded in ^obtaining a delicate fibre
which
384 On the Fibres used in Micrometers, &c.
which enables us to remove the error of inflection, while it possesses the requisite properties of opacity and elasticity. This fibre is made of glass, which is so exceedingly elastic, that it can be drawn to any degree of fineness, and can al- ways be procured and prepared with facility; a circumstance of no small importance to the practical astronomer, who is frequently obliged to send his micrometers to a great distance to be repaired.
It is evident that this vitreous fibre, when drawn from a hollow glass tube, will also be of a tubular structure, and that its interior diameter may always be regulated by the inner diameter of the original tube. When the fibre is formed, and stretched across the diaphragm of the eye-piece of a telescope, it will appear perfectly opaque, with a deli- cate line of light extending along its axis. This central transparency arises from the transmission of the incident light through the axis of the hollow tube : and since this tube can be made of any calibre, we can also increase or di- minish the diameter of the luminous streak. In a micro- meter which I have fitted up in this way, the glass fibres are about the 1200dth part of an inch in diameter; and the fringe of light which stretches across their axis is distinctly visible, though it does not exceed the 3000dth part of an inch.
In using these fibres for measuring the angle subtended by two luminous points, whether they be two stars, or the op- posite extremities of a luminous disc, we may, as has been done hitherto, separate the fibres till the luminous points are in contact with their interior surfaces ; but in order to avoid the error arising from inflection, I would propose to separate the fibres till the rays of light issuing from the lu- minous points dart through the transparent axes of the fibres. The rays thus transmitted evidently suffer no inflection in passing through the fibre to the eye ; and besides this ad- vantage we have the benefit of a delicate line about one third of the diameter of the fibre itself.
I am, dear sir, your most obedient servant,
D. Brewster. To Mr. Tilloclu
LXVIII. Oh-
[ 385 ]
LXVIII. Olservations suggested by the Geological Paper of Mr. John Farey in last Month's Philosophical Magazine.
To Mr. Tilloch, — Sir, J. he geological facts communicated by Mr. John Farey, in his Piper commencing your last month's Number, are in, an eminent degree instructive and interesting. It is only from the itinerant geologist cautiously pacing over various and extensive districts, and marking, with experienced in- telligence, the wonderful phsenomena which every where present themselves, that we can hope to obtain that accu- mulation of practical facts which can alone guide us to a sober and correct theory of the natural causes which, at re- mote periods, have operated those stupendous changes which are every where seen on and near the surface of our globe.
The almost infinitely diversified exterior of the earth, and its universal stratification, furnish the most interesting sub- jects of inquiry ; and every natural inequality upon, and every bed which reposes beneath, the surface is connected with a history which well merits, and can only be developed by, the researches of the strongest intellect. Indeed the common mind is overpowered by the stunning magnitude of geological facts; it shrinks from the bold but just con- clusion, that the lowest stratum which the deepest excava- tions into the earth have yet reached, was once itself a sur- face, and that the highest peak of the loftiest stratified mountain is only the remaining speck of a fast country which once spread itself out on the same, and in many in- stances much higher, level : the mountain deriving its pre- sent form and exaltation, not from masses of matter suc- cessively piled up by unknown means, but solely from th« superior durability of its materials, which have withstood th<* operation of those tiemendous agents, that have swept away the surrounding country in which it was imbedded, leaving the mountain itself a magnificent land gauge, by which to es- timate the immensity of the tracts that have disappeared. The formation of mountains in this way, and that of the exten- sive strata of the earth, mutually elucidate each other. The
Vol. 33. No. 133. May 1 .09. B b incal-
386 Observations suggested by
incalculable masses of materials necessary to form the latter, could only be derived from the destructive transportation of other strata equally extensive; and the present elevation of stratified mountains is demonstrative evidence of the former existence of the countries which, in disappearing, have furnished such vast masses of diversified material for the formation of other stratified countries in other situations. These simple and sublime geological truths, however they may now shock minds unaccustomed to the contemplation of natural grandeur, will, at no distant period, be as gene- rally assented to as the gravitation of Newton.
The just appreciation of geological phenomena is amongst the most creditable things of modern science. Already are the ignesjatui of hypothetical invention disappearing, and we no longer hear of seas fourteen thousand feet above the level of the present ocean retiring into cavernous recepta- cles, or of the exaltation of continents, to equal heights, by vulcanian energies. Forged in the same fabulous workshop, they are already slumbering on the same shelf with the vi- treous sparks of Buffon.
The great source, I conceive, of all hypothetical reason- ing on the formation of the earth arises from the mistaken opinion, that the- present laws of nature are insufficient to account for past effects ; without duly considering, that the natural causes which are now operating changes on our globe have been in action millions of years, and that it is the almost infinite duration and variance of their action, rather than the apparent little which we can now perceive them performing, that will enable us to account for the stu- pendous effects which they have accomplished. The system- builder by a deluge, an internal fire, an external crust, the vicinity of an erratic planet, or some such fanciful creation, is for accomplishing, almost in an instant', that which, far more probably, required many thousands of years to effect ; and it assuredly is a rigid attention to, or disregard of, the two important circumstances of time and agency, that marks the boundary line between fanciful hypothesis and genuine theory. When the investigator flies off in' search of a cause which no longer exists, or no longer operates within the
. sphers
Mr. Farcy's Geological Paper. 337
sphere of his inquiry, he is certainly indulging in hypo- thetical visions; but when he fairly generalizes, by some common agreement, a multitudinous class of acknowledged phaenomeria, and directly connects them with causes still in operation, he is developing a lucid theory which will en- lighten and improve.
It is this departure from nature, by an assumption of ex- tinct or imaginary causes, that has induced me to offer the present observations. The closet geologist may be expected V) indulge himself in the creation of hypothetical phantoms; but that he who has had the great and instructive volume of Nature spread out before him, and, page after page, has read, in her indelible and expressive characters, the history of her magnificent transactions, should imagine her present ener- gies unequal to her past performances, and that "others must be sought for in lunar regions, forsooth, is at once matter of surprise and regret.
I apply this to Mr. Farev, but with the utmost deference for his practical knowledge. In any thing relating to effects which have taken place, and to practical facts resulting from extensive personal observation, he is clear, correct, and in- structive; but the instant he attempts to develop cause, the genuine spirit of philosophy forsakes him, and he becomes bewildered in the unprofitable maze of hypothesis. Mr. Fa^ rev is evidently preparing to add one more inventive system to the many that have already so much retarded the progress of real knowledge, by the introduction of a non-existent satellite at some indefinite time, and from some indefinite re- gionj whose near approach to the earth is to reverse the ac- tion of gravitation, and undulate or distort the upper strata into some or all of their present irregularities. Before further committing himself, it will be well for Mr. Farey to consider whether, by the promulgation of a hypothesis so utterly incongruous with all the present operating laws of Nature, he is not about to sacrifice much of that fair fame Which his practical researches have so deservedly assigned him.
A system-builder, like a religious or political bigot, is tver a most irritable being, and to prick his favourite bubble
B b * is
3S8 Observations on Mr. Fareifs Geological Paper.
is to explode aU his virulence : but I confidently trust that Mr. Farey will be found a distinguished exception to this, and that he will hail with approbation a liberal criticism which has solely in view the expulsion of error from his favourite pursuit, and the recalling of his attention within those sober limits which experience and observation so justly prescribe. A dwarf stationed on the shoulder of a giant can see further than the giant himself; and if I assume this visual preemi- nence, it is only to acknowledge the Colossus that supports me.
Certainly the great and most desirable desideratum in ge- ologv is to account, satisfactorily, for the original formation of all stratified countries ; and when that has been clearly accomplished, all irregularities and anomalies in the strata themselves, which have hitherto been almost the only cir- cumstances attended to, will be comparatively an easy at- tainment; for it is impossible to doubt that the same power- ful agent, whatever it may be, that has given mobility and transportation to such massive and diversified materials, and has spread them out, on so gigantic a scale, over the face of the globe, must also be equal to their separation, disruption, denudation, excavation, and almost every other geological appearance which observation has discovered.
And I have only to advance one step further and add, that the only a^ent in nature, with which we are acquaint- ed, and to whose action we can assign, with any colourable probability, all these extraordinary and stupendous effects, is water.
To this powerful and incessant operator allow but a suf- ficiency of duration, and a suitable diversity of fluctuating circumstance, and he will have a bold and arduous task to perform who shall undertake to advocate its limitation in geological efficacy. And here it is that I would- more espe- Gialiy solicit the attention of Mr. Farey, by urging him to relinquish his aerial assistant, which does not untie, but clumsily cut, the Gordian knot, and substitute in its stead iinple and natural instrument, in which he will expe- xience a power and pliability (if action competent to the il- lustration of almost every geological phenomenon. It is,
however,
Introduction to the Study of Mineralogy . 389
however, I think, very unfortunate for Mr. Farcy himself, that he either does not perceive, or is strangely indisposed to admit, the most obvious effects of water on the surface of the earth. A decisive and very singular proof of this is given in that most extraordinary and unphilosophical con- clusion which he draws on the formation of valleys, and which unquestionably detracts, to an extent which he can- not be aware of, from his other acknowledged merits as an observing naturalist.
The action of water, fn operating extensive changes on our earth, naturally divides itself into two distinct branches ; those changes which are effected by streams of fresh water running over the surface, and those far more mighty ex- terior and interior changes which the ocean itself has ac- complished, during the submersion of our present continents.
Were there any probability," Mr. Editor, that these cur- sory remarks of mine could merit a place in your most re- spectable repository of scientific knowledge, 1 would pursue the subject in two subsequent papers on both of these branches; first by investigating, circumstantially, the form- ation of all valleys through which streams are now running, and afterwards adverting to the diversity and magnitude of marine action. I am, sir,
your most obedient humble servant,
John Carr.
Princes Street, Manchester, May 13, 1809.
LX1X. Introduction to the Study of Mineralogy* By M. Hauy*.
If the motives which invite us to cultivate a natural science were founded merely upon the interest which certain pro- ductions of themselves inspire, and upon what appears at first sight attractive, zoology and botany would seem to have a preponderance over mineralogy which would attract a greater number of admirers.
* This is a translation of M. Hauy's Preliminary Discourse to his celebrated Woflt on Mineralogy.
B b 3 Minerals,
390 Introduction to the Study of Mineralogy,
Minerals, for the most part being hid within the cavities of the earth, only come out of it in fragments, and bear the marks of the iron instruments that have been employed to tear them from their beds : to the generality of mankind they are only crude masses, without character and without appropriate definition, and appear as if intended solely to be appropriated to our wants. It has seldom been imagined that a distinct science could have been reared out of the sub- ject, and that the naturalist should hold a place between the miner who extracts the treasures of Nature from the earth, and the artist who works them.
Those however who, without dwelling upon first ap- pearances, will consider minerals more closelv, and with long continued attention, will easily perceive how much is to be gained by a more intimate acquaintance with their properties.
Polyhedric forms, the dimensions and angles of which appear to have been regulated by a scientific hand with the assistance of the compass ; the variations which these forms, without ceasing to be regular, undergo in one and the same gubstance ; and the advantage of being able, by the help of calculation and observation, to re-discover the traces of Pro- teus concealed under these metamorphoses ; ingenious ex- periments concurring with indications which speak at once to the eye, in order to develop the properties which escape him ; the principle of Archimedes applied to the comparison of weights under a given volume ; the refrangent power em- ployed in tracing a limit between bodies through which the image of each object appears simple, and those which pre- sent two to the astonished beholder; heat substituted for friction in order to produce electrical poles, in bodies the crystalline form of which, by particular modifications, in- dicates beforehand the positions of these poles; the mag- netic needle making use of iron to disclose itself; various chemical agents presenting methods of dispelling doubts which other experiments had still left ; the resources fur- nished by analysis for the formation of a method grounded Upon the intimate knowledge of the objects which it em- braces -, every thing conspires to make mineralogy a science
worthy
Introduction to the Study of Mineralogy, 39 1
worthy of being received by minds naturally inclined to in- quiries susceptible of precision and vigour, presenting in- genious combinations, and a collection of facts closely con- nected with each other.
To such minds mineralogy presents itself under a new aspect. It is a picture which is embellished by the mere habit of seeing and studying it ; in which Nature exhibits herself, as she does every where else, under an aspect which claims for the Creator the tribute of our homage and admi- ration.
Mineralogy embraces a multitude of productions which human industry has not yet been able to mould to the wants or pleasures of life, without a certain study of their cha- racters and of their nature, and without which art could not possibly clear the paths of science. From the earliest times the collection of these familiar productions had been subdivided into stones, salts, bitumens, and metals. The methods of the mineralogist are, as it were, the first out- lines of a picture. The working of metallic substances had shown several essential differences which distinguish them. Among the stones there have been composed numerous groupes under the names of marbles and gems, which, not- withstanding the disparity of the bodies which they served to connect with each other, were attempts at the formation of the genera which subdivide the classes. Certain proper- ties, remarkable from their being elicited under certain cir- cumstances only, have not escaped attention : the attraction exercised by amber when rubbed over light bodies, and the kind of sympathy between iron and the magnet, which had been considered as a simple stone, have all been observed. Even the forms of crystals were not wholly unknown to the ancients: that of rock crystal and of the diamond have been distinctly alluded to by Pliny*. The regular polyhedrons, which at present excite our admiration from their multitude and diversity, were then also remarked as wonderful singu- larities.
It is only since the commencement of this century, how-
# Hist. Nat. 1. xxxvii. c. 2 ft 1.
B b 4 ever,
$$$ Introduction to the Study of Mineralogy.
ever, that the learned have begun to submit the assemblage of inorganic bodies to methodical arrangements, and that the term mineral kingdom has been adapted. Among the various systems which have successively appeared, some of them, such as those of Linnaeus, Wallerius, Daubenton, &c, employ in the determination of the species, genera, orders and classes, certain characters which are, as it were, presented to the naked eye; such as those which are derived from the form, texture, and transparency of the colours ; or certain properties easily verified, such as those of emitting light with steel, effervescence with nitric acid, he. Other systems, subjected to a more scientific progress, as traced by Cronstadt, and followed by Bergman, Born, Kirwan, &c, present the series of minerals classified according to their analyses ; so that, the species being determined by the identity of the component principles, the genera are formed of species which have a common principle. The same method also serves in certain cases to connect together several genera in one and the same order: thus the neutral salts may be sub- divided into alkaline salts, earthy salts, and metallic salts, according to the kind of acid united to an alkali, an earth, or a metal. But when analysis failed in enabling mineralogists to form orders, its place was supplied by some chemical property common to all the genera of which each order wras the assemblage ; and with respect to the classes, they were in the same way characterized after the manner in which the substances which composed them were modified in the various operations which spring from chemistry.
It must not be thought, however, that there was a line of separation clearly traced betwen the two modes of me- thodical distribution which we have mentioned. Chemists, after having determined the series of the classes, orders, ge- nera, and species, by the help of chemical properties, or of the results of analysis, could not descend to the varieties, except by employing external characters in order to distin- guish them from each other. Now, in a complete method, we are the less entitled to dwell upon the species, as they 4re frequently ramified into several subdivisions, the diffe- rences of which; much more striking than those light and
fugitive
Introduction to the Study of Mineralogy. 393
fugitive shades which modify the varieties in botany, pre- sent, from the different laws or' Nature, or from the different ways in which she operates, results very dist.nct. In calca- reous species, for example, the various crystalline forms, stalactites, marbles, Stc, are so many modifications of one and the same substance, which, without doubt, deserve to be separately observed and studied ; and if in all these we were not to see any thing but lime and carbonic acid, it would be as if we contented ourselves with the inscription of a picture equally interesting by the assemblage and by the variety of its objects.
On the other hand, it is evident that mineralogists have really profited to a certain point, by the results of che- mistry, in order to form the distributions which have been designated by the term mineralogical methods : for without speaking here of the use which they have made of certain properties, such as effervescence with the acids, which is a true chemical property, they never could have been able, without the aid of analysis, to refer subsances to their true classes. The carbonate of lead, commonly known us white lead, was regarded as a species foreign to the metals, and was probably arranged among the stones. In the Brisgaw, a few years ago, there was found a crystallized substance with small incrusted lamin2e, and of a white colour : mine- ralogists had alternately regarded it as a zeolite, and as a ponderous spar. The analysis of Pelletier, however, assigned its true place, as being among the ores of zinc, by the name of calamine.
Chemistry ha-? therefore been, at least tacitly, the guide of mineralogists in the determination of species ; and the formation of the genera is really the point at which systems in every respect begin to diverge.
In those of the mineralogists, the species which compose one and the same genus are connected with each other by a character derived from some quality which is common to them, or by several characters so combined that their as- semblage is considered as belonging only to the collection of the species in question. The genera adopted by cheuu^s baye their foundation in analysis itself: they depend, as we
have
S94 Introduction to the Study of Mineralogy.
have said, upon the existence of a principle common to the different kinds, the distinction of which afterwards bears upon the principles which are peculiar to them.
We see from what precedes, that chemistry and mine- ralogy necessarily concur to the formation of a method, whatever it may be, which has for its object the classifica- tion of inorganic bodies ; that it belongs to chemistry to lay the first foundations of the method by the determination of the species ; and that the difference depends upon what is contributed by each to the construction of the edifice which is raised upon that basis. I shall soon detail the principles which seem to me to conduce to the most advantageous ap- plication of this kind of alliance.
On the other hand, natural philosophy unites with che- mistry in order to furnish mineralogy with distinctive cha- racters, the more advantageous from their diving to the very bottom of substances, and they are much less variable than those of which we judge only with respect to the manner in which they strike our senses. Experiments equally simple and easy seem to give us new organs, in order to penetrate to the most intimate properties of a substance : and we may answer those who think that mineralogy is sufficient for its own wants, without intermixing with foreign substances, that in operations so elementary, and requiring so small an expense, we see neither the naturalist nor the chemist pro- perly so called, but the mineralogist alone, interrogating nature in a more urgent and more fortunate manner*..
Geometry, in its turn, has direct and necessary relations with mineralogy, by the description of crystalline forms, and still more by its numerous applications to the structure of crystals, which, of itself, is only the result of a natural
* Although this simple indication of chemical and physical properties be sufficient for fulfilling our principal object, wc have thought it right to add the explanation of these properties, and thus to labour for men more particu- larly versant in the sciences by which mineralogy may be extricated from the Jabyrinth of phrases purely descriptive, and be raised to the rink of the true sciences, which aggrandize their object by ascending to the laws to which thev are subjected. They will of course do us a service, if they do not con- fine us to the results of solitary experiments, but, on the contrary, proceed to show their connection with the causes upon which they depend.
geometry,
Introduction to the Study of Mineralogy . 395
geometry, subjected to particular rules, and by which each j^olid has its figure determined by the combination of an in- finity of other small solids, which are like the elements of the first. A hasty glance at crystals will obtain for them the appellation of pure lusus natures ; which is only an ele- gant way of confessing our ignorance. A closer examina- tion unfolds to us the laws of arrangement in them, by the aid of which calculation represents and unites to each other the results observed ; laws so variable, and at the same time so precise and regular; simple in the extreme, yet display- ing the utmost fertility.
The theory which has served to develop these laws, rests entirely upon a fact the existence of which had been hi- therto rather presumed than demonstrated. It consists in this, that these small solids, which are the elements of cry- stals, and which I call their integrant molecules, have, in all those which belong to one and the same species of mineral, one invariable form, the faces of which are in the direction of the natural joinings indicated by the mechanical division of these crystals, and of which the respective angles and di- mensions are given bv calculation combined with observa- tion. Besides, the integrant molecules relative to different species also have diversities among them more or less re- markable, except in a very few cases where their forms have characters of regularity, whence result, as it were, points of contact between certain species. It follows from this, that the determination of the integrant molecules should have a great influence over that of the species ; and this consideration has led me more than onee, either to sub- divide into several species a groupe which, in the ancient methods, form only one, or to refer and re-unite the scattered members of a single species, of which several distinct spe- cies had been made. Some of these separations and re- unions, made at a time when analysis had not yet unveiled the true nature of the substances which were the object of it, are now confirmed by chemical results ; and I shall even venture to say, that upon the hypothesis that no mineral Substance had been as yet decomposed, wc might, by a con- tinued investigation of the integrant molecules, form assort- ments.
396 Introduction to the Study of Mineralogy.
ments, which we might be justified in regarding as belong- ing to so many species distinctly circumscribed * : so that, in order to distribute them afterwards in a well arranged me- thod, it would be sufficient to have the analysis of one single body taken in each.
From this we may conceive in what sense to understand what I have above hinted at, namely, that to chemistry be- longs the determination of species. It would perhaps be more correct to say that it completes this determination by making us acquainted with the principal molecules, of which the integrant molecules are the assemblages. Already it is easy to perceive (and the subsequent part of the work will contain several examples) how interesting it is that the in- quiries relative to these two kinds of molecules should con- spire towards one common object ; that the chemist and the mineralogist should mutually enlighten each other by their labours; and that goniometry, which furnishes data for sub- mitting crystalline forms to calculation, should be associated with the scales that weigh the products of analysis.
The principal object of this Treatise is to detail and de- velop a method founded upon certain principles, and which serves as a kind of survey to all the information presented by mineralogy, assisted by the different sciences which can go hand in hand with it in one and the same line. It is calculated to bring all the minerals known under one and the same point of view, in order to compare them with each other, to study their characters, and to investigate alter- nately by experiment and theory the different phaenomena of which they are susceptible. Every thing which can procure the observer the double advantage of being at once guided and enlightened during his progress will be employed ; and
* These assortments would not be limited to crystals properly so called : ye might also include lamellated masses, or even those which caimot be sub- jected to a mechanical division : for these last have frequently, when com- pared with analogous crystallized substances, a relation, in point of position and aspect, which ascertains them to belong to the same species: and thus these masses, insignificant in themselves, may be determined, at least inter- mediately, by the assistance of crystals which serve them in seme measure as interpreters.
this
Introduction to the Study of Mineralogy, 397
this upon the principle that every science embraces every other science necessary to its elucidation.
Mineralogy, in order to be successfully cultivated, re- quires extensive preliminary knowledge and persevering in- dustry. It is the lot of all the sciences, that, in proportion as they acquire new degrees of perfection, they require ad- ditional efforts also, in order to attain the point at which, as from an elevated and commanding eminence, we can em- brace at one glance a greater number of truths.
The result of my investigation, even supposing it to be as complete as possible, could not be regarded but as an in- troduction to the study of Nature. The different substances of which the globe is composed, placed in their respective positions by the concurrence of various causes, the actions of which have been directed by the Supreme Being towards the object proposed by his wisdom, present a spectacle per- fectly novel, even to the eye the most familiarized with the aspect of minerals transported from the bowels of the earth into our collections. Here we see them collected and dis- posed in a perfectly symmetrical order; and Nature, break- ing through on all sides the artificial limits traced by our systems, separates what we had united, while she associates and confounds those which we had separated. On one hand she exhibits, by striking contrasts, substances which touch and adhere together ; and on the other hand she exhibits certain gradual transitions from one substance to another: — those are the successions of shades, which call upon a judi- cious observer to remark : Here, the substance before us is no longer such a mineral, nor is it any longer such another.
We may easily conceive how useful and even necessary a preparatory study is to the naturalist, to enable him to derive more benefit from his travels, and from observations made upon the spot. Objects already familiar to him, dispose linn to form an acquaintance with those which will be new to him : he has not yet seen Nature herself, but he has received eves for the purpose.
Although the observations here alluded to belong to a branch of suience which has been called geology, the know- ledge
$98 Introduction to the Study of Mineralogy .
ledge to which they lead appertains too closely to mineralogy to be omitted in a treatise relative to this last science. I shall confine myself to the mention of some general facts, the existence of which is confessed by several celebrated ge- ologists; and ?hall subjoin an abridged description of the va- rious aggregations known by the name of rocki, and of others which are nothing else than grouped or mixtures of mincralogieai species. Those who desire more detailed no- tions mav derive them from the works of Deluc, Saussure, Dolomieu, Pallas, Ramond, and other scientific men who have seen Nature upon a large scale, and have acquired from her a right to describe her phenomena.
But independently of those who are led by a particular taste towards researches which are the result of travels and voyages, there exist men every where, who, while re- siding in towns, are desirous of procuring useful informa- tion respecting the various mineral productions of Nature ; and mineralogy has this advantage over the animal and ve- getable kingdoms, that the collections of objects connected with it are more plentiful, and susceptible of fewer chasms, on account of the smaller number of species,, while they are also less exposed to deterioration, and may be studied with delight at all seasons and in all places. I have flattered my- self that there would be found in this work an additional facility for acquiring the knowledge so proper for adorning reason and cultivating the mind, and for exciting in the soul a becoming?; gratitude for the benefits conferred bv an all-seeing Providence. With the view of attaining everv object connected with the science, I have given, as often as opportunity offered, an idea of the purposes to which the minerals are applied, and of the processes employed by artists in order to render them fit for the use of mankind.
To return to the method which I have adopted in the classification of minerals. In the first place I resolved to direct my steps, as far as I could, by chemical results. Where, in fact, can we find relations more proper for closely connecting various mineral substances with each other,- than those which are founded upon the existence of one identical
principle }
Introduction to the Study of Mineralogy . 399
principle ? Where can we find differences more striking, between the same substances, than those which depend upon principles peculiar to each ? Now, when we classify the substances of one and the same kingdom, we establish a continued comparison between them, according to the re- lations which connect and the differences which separate them. This comparison will therefore be the most exact, and at the same time the most natural possible, and the least arbitrary, if the method chosen for establishing it is that which unveils to us the intimate composition and foun- dation of each substance, which teaches us what it is in it- self, rather than that which only shows us the outlines, or perhaps the external effects.
We may remark, before going further, that there are in the present case two problems to solve. The first consists in dividing and subdividing the collection of substances which a system should embrace, so that each may hold its true place. This is called classifying. The second has for «its object the furnishing of easy and convenient methods for characterizing each substance in such a manner that we may ascertain it, wherever it presents itself, and discover in the system the place which has been assigned to it. The solution of the first of these problems is the sole object at present.
Let us now examine what are the resources presented to us by the present state of science, in order to attain this ob- ject. Among the minerals which in the common methods- compose the class of stones, there are several in which ana- lysis has demonstrated the presence of an acid combined with an earth. Such are the calcareous carbonate of the modern chemists, calcareous filiate, barytic sulphate, &c. Other substances, such as the emerald, topaz, garnet, 8cc.r have only presented earths combined with each other, and sometimes with an alkali. We shall for a moment lav- aside these last substances, in order to speak of those which contain an acid in their composition.
Here an important consideration presents itself relative to the distribution of these compounds. The modern chemist?, in 'forming the table of the results of that new.system whicri
changed
400 Introduction to the Study of Mineralogy.
changed the face of science, by arranging in genera and species the acid substances, made choice of the acids for characterizing the genera, and distinguished the species ac- cording to the diversity of the bases united in succession with one and the same acid. This method of classifying seemed to be pointeu out by the course of their operations alone. Oxygen being the acidifying principle, the common generator of the acids would become, by this kind of univer- sality, the primitive substance, the different combinations of which with the different acidifiable bases we should first consider: and by a natural consequence, the acids resulting from these combinations would become, in their turn, the general terms to which we should refer the classification of the different and more compound substances of which they form part. The activity and energy of those principles which have so strong a tendency to unite themselves with the earths, the alkalis, and the metallic oxides, and seemed to rule over the combinations into which they entered, pre- sented a new reason for assigning them the first place in these very combinations in which they then formed the principal part. But the mineralogist, whose object simply is to apply the results of analysis to the works of Nature, sees things in another point of view, and is necessarily led to choose the most fixed principles, as the common ties of the different species which ought to concur to the formation of genera.
In order to place this truth in its proper light, we may remark that, among the metallic substances which form one of the great divisions of the mineral kingdom, several admit an acid into their composition : hence it results in the first place, that, by giving the first rank to the acids, we could not avoid associating together in one and the same genus, on the one hand, carbonate of lead with carbonate of lime and barytes; on the other hand, the sulphate of iron with the sulphate of lime and that of magnesia ; and so on with several other relations, in order to preserve the unity of the genera. Besides, by reasoning from combusti- bles, which frequently form part of the acids, as with these
acids
A new Method for detecting Arsenic. 40 L
acids themselves, we should be forced to place together the sulphuret of iron, the sulphuret of lead, the sulphuret of zinc, &c. This is not all : the oxygen which should have determined the preeminence granted to the acids of which it is the generator, would obtain it for itself for a stronger reason, relative to its combinations with the metals, known, by the name of metallic oxides, which would still form a single genus. It would remain to mark these places of the native metals in this distribution, and it seems that the only part to take would be to associate them also in one and the same genus.
[To be continued.]
LXX. A new Method for detecting Arsenic- By Joseph Hume, Esq., of Long Acre } London.
To Mr. Tilloch, — Sir, Jl ew chemical tests are so interesting as those which dis- cover the presence of a poison, particularly that of arsenic. It is not merely to the chemist or the mineralogist that such assistance is advantageous, but it is often of the greatest importance to the administration of public justice, where tile innocence or guilt of the accuseu depends frequently on no other evidence than the existence of this most deleterious substance.
The methods principally adopted are few, perhaps not more than five; and though either of these, in many in- stances, may sufficiently answer the end, yet, when the quantity of the arsenic is extremely minute, I fear these are liable to objections, and the results may be ambiguous.
The latest observations on this subject are, probably, those of doctor Bostock, which were read before the Liver- pool Medical Society. As I have not been that gentleman's paper, excepting merely so much as is detailed in the critical analysis of books, published in the last number of " Medical and Physical Journal," I am not aware of any new instruc- tions or cautions to render the usual methods more certain ; but the test which I propose as a substitute, appears to be more efficacious, in as much as it produces a more copious
Vol. 33. Np. 133. May 180Q. Cc precipitate
402 On the present Mode of finding
precipitate from a given quantity of the arsenic ; the result in all cases must, therefore, be nearer the truth, being more evident to the senses.
One experiment will sufficiently elucidate the plan I pur- sue. Let one grain of white oxide of arsenic and the same quantity of carbonate of soda be dissolved by boiling, in 10 or 12 ounces of distilled water, which ought to be done in a glass vessel; to this let a small quantity of the nitrate of silver be added, and a bright yellow precipitate will instantly appear. This is a more decisive test than sulphate of cop- per, which forms Scheele's green (arseniate of copper); and though my process answers very well with potass or even lime-water, yet I am inclined to prefer the common sub- carbonate of soda. I remain, sir, your obedient servant,
Jos. Hume.
Long-Acre, May 19, 1809.
LXXI. On the present Mode of finding the Rates of Timekeepers. By a Correspondent.
vJf all the requisites by which a seaman is enabled to con- duct his ship from one distant climate to another, no one appears to be of greater importance than an accurate know- ledge of the time. The parliament of Great Britain, aware of its necessity, have, for the last century, offered a large reward to any person who may contrive a machine, that will keep time within certain limits of error during a long voyage. So anxiously has this been desired by that part of the nation who have any interest in its commercial or maritime con- cerns, and so great has been the honour awaiting the per- son who shall produce this desideratum, joined to the in- citement naturally arising from the hope of obtaining a large reward, that many ingenious watchmakers and mechanics, both at home and abroad, have exhausted their utmost skill in the endeavour to bring it to perfection. Although they have hitherto found this impracticable, yet by the repeated attempts, and successive improvements of various hands, such an approximation to the truth has been attained, as
reflects
the Rates of Timekeepers. 403
Reflects great credit on their ingenuity; and it would be un- just not to allow them this tribute of praise, when, for want of reaching precisely to the point required, they are deprived of those advantages, and remunerations for their trouble, which would in that case so justly become their due. Too frequently indeed does it happen in this country, that the most useful and ingenious mechanics, who have been re- duced to indigence by attending perhaps to contrivances for the general good, rather than to their interest by labouring in the old beaten track, are suffered to pine in want and languish in distress ; whilst pretenders and quacks have risen to affluence, basking in the sunshine of favour, although deluding the public with one hand, and picking their poc- kets with the other.
Few persons who have read the marquis of Worcester's- Century of Inventions, and know the fate of his machines, have not regretted, that no attention was paid to his peti- tion, for pecuniary assistance to enable him to complete these inventions* and publish them for the general benefit of mankind ; more especially* as we are now convinced from the circumstance of many of them having been reinvented, that they were not the idle fancies of a lively imagination, but that they were realities, which he had actually con- structed and applied to practice. Indeed at present, there is not any one department of the abstruse sciences, which can boast of receiving that encouragement or support, which, from its value to a commercial nation like Great Britain, it has a right to expect.
It may appear rather extraordinary at this enlightened pe- riod, when so many improvements have been made in in- struments, and so great a degree of accuracy attained in practical astronomy, that the present mode of ascertaining and applying the rate of a timekeeper, practised in our fixed observations* should be called in question : and although I have looked over most of the publications on this subject, yet I am not aware of any arguments by which it can be justified.
The object intended by obtaining a rate, is to predict how far from truth the chronometer will be at the end of a given
Cc2 time;
404 On the present Mode of finding
time ; and to ascertain the degree of dependence that can be placed upon it, during the intermediate part of that time : or, to find whether the quantity of error increases uniformly and regularly in proportion as the time increases. It would seem, that in all the trials hitherto made of timekeepers in fixed observations, this object has only been partially pur- sued ; whilst another of equal importance has been alto* gether neglected : that is, no method has been adopted, for finding the unavoidable alteration in the rate, produced by the different changes of temperature, to which most long voyages are liable : but on the contrary, the rate has been ascertained, merely for that temperature which happened to occur whilst it continued under trial, without endeavouring to find, whether any change would take place in the rate, if a material alteration should be produced in the weather, from heat to cold, or from cold to heat.
Can it reasonably be expected, in machines like these, that a rate found in a temperature of 30° of Fahrenheit, without any greater variation than lo3 en either side, will be ade- quate to compute forward, and find the error of a watch that is afterwards to be kept going in a temperature of 100° or higher, wherein the expansion of the metals is so diffe- rent from that of the former? It has also frequently hap- pened, that the rate has been obtained in the coldest part of winter, when metals are most contracted, and applied to the hottest part of summer when they are most dilated, without any correction for the unavoidable defect of exact compensation ; or that the rate has been found in a very cold latitude, to apply to the going of the watch in a very warm one ; and vice versa.
\ Perhaps it may be asked here, Then of what use is your compensation ? To which I reply, The value of this com- pensation in the balance is not depreciated because the ut- most degree of perfection cannot be attained in adjusting it, anv more than the value of the chronometer because it does tiot keep exaetly with mean time, or any more than the in- direct method of finding the true from the mean anomaly, because it is done by means of an approximation.
When chronometers have 5een sent on trial for twelve
month*
the Rates of Timekeepers. 405
months or more, it has been the general practice to com- pute forward with the fir? t month's rate, (no matter what time of the year, or in what temperature it has been taken,) and to compare this computed error with the actual error shown by the watch, at the end of each succeeding month that it continued under trial. Now it is evident, that unless the timekeeper could be accurately compensated for the erl'cts of heat and cold, which is seldom the case, there must arise a very material difference between these two rates, when any change has occurred in the temperature ; and that a very smaU defect m the compensation must produce a very large deviation from the computed rate, by placing the watch to go in a different temperature, whether considerably warmer or colder, than that in which the first month's rate was found. Hence, if it should so happen, that the month's rate on which this computed error is founded, has been taken in January, when the thermometer was at 30° ; then in July, when it is at 80°, the error in some cases becomes immense, but in most cases of too great consequence to be altogether neglected. In- deed, let this be taken in any part of the year, there is a great probability against its having been taken in that month, wherein the mean temperature occurred, of that season during; which the watch continued there for trial. On the contrary, if the change of rate arising from the alteration of temperature be taken into account, and applied with the computed rate, an essential defect in the going of watches will thereby be obviated, and they will be found to have gone considerably nearer than people now believe they have.
Some of the best makers of chronometers, at the time of delivering them to the purchasers, have told them, how much the daily rate would vary between the heat of summer and the cold or* winter. Although this is but a vague sort of statement, yet I beiieve few seamen, who know how, have failed to take advantage of it, and to apply it on all occasions where they could. But it has met with a very dif- ferent fate in our observatories, and has not only not been applied, but has been condemned, and declared improper to be admitted there. Indeed, we have one publication ex- tant, wherein it is expressly asserted, that as the act of
C c 3 parliament
406 On the present Mode of finding
parliament makes no mention of the rate, therefore the aU lowance of a rate is an indulgence ; and that the commis- sioners might require the maker to adjust the watch, so as to keep mean time accurately. With as great propriety might it be said, that the placing a glass over the face to view the hands and figures is an indulgence ; or that to make the balance of two or more metals is an indulgence ; or that the watchmaker having the power of choosing his own escapement is an indulgence; or lastly, that the astronomer being allowed to take the moon's place from the Nautical Almanack, instead of computing it with proper data and La Place'? equations, is an indulgence. The act prescribes no definite means by which the object is to be attained, but leaves the artist entirely to his own choice: it cannor there- fore but appear extraordinary, that the act should be thus construed, to the exclusion of the most essential part of the principle on which the method is founded.
Those who are acquainted with the adjustment of the balances of timekeepers know, that it is almost an impossi- bility to bring them precisely to that minute point of exact* ness, by which alone they keep accurately with mean time ; and the difficulty of adjusting the balances for the effects of heat and cold, so that they shall never vary with the greatest extremes of either, would be at least as difficult to accom- plish. But the former is attended with no other trouble to the practical navigator, than merely requiring the aid of a little calculation to a\low for the deviation. It would be precisely the same with the allowance for the effect of the alteration of temperature: and it cannot therefore but appear extraordinary, that any objection should be made against applying this correction, when, by means of it, so much greater dependence can be placed on the time shown by the machine. Art has always lent her friendly aid to science, and science should return the kindness. Little can be ex- pected in the progress of the longitude by either of them separately ; but when they cordially unite their efforts, what is there that they cannot subdue ?
Nothing would tend more powerfully to advance the in- terest of our own countrymen, than the establishment of a
public
the Rates of Timekeepers. 407
public observatory, for trying timekeepers and keeping their rates ; to which every maker of them, if he thought proper, might have access at stated hours, and be allowed always to keep there a certain limited number of pieces. Here he could try the effect of improvements, and gain experience thereby ; then alter, and try again, until he succeeded to his mind : an advantage which he could not perhaps en- joy in his own house, for want of instruments of sufficient accuracy, and leisure to make the necessary computations.
A book containing the rate of each timekeeper belonging to each person might be kept, always ready for the use of the owner, and, if he thought proper, for the inspection of the public at large ; by which, he would be enabled to fix a price on the machine, proportioned to the excellence of its going, and avoid all suspicion of partiality in giving the rate of his piece to the purchaser,
From this place, captains of ships or others might always be furnished with timekeepers, suitable to the price they could afford, or adapted, with respect to accuracy of going, for the purpose they might be required to execute.
In short, so many advantages would evidently be derived to the makers, and the public, by an institution of this kind, which could not fail to bring forward deserving merit as a claimant on public favour, that I am surprised the watch- makers have not established one at their own expense, by subscription, as the amount of it when divided between a number of proprietors would not be an object to each indi- vidual.
There are many situations near London that are well adapted for the purpose ; the instruments necessary for it would not be expensive ; and a steady careful person, capa- ble by his scientific knowledge of conducting it with ability, might no doubt be found, who, considering it as an amuse- ment rather than a labour, would be moderate in his terms for the discharge of a duty, which must evidently be bene- ficial both to the venders and the purchasers of these useful and necessary machines.
T.
C c 4 LXXII, Pro-
t 40S J
LXX1T. TrorC( dings ofLearne'l Societies*
ROYAL SOCIETY.
IVl ay 4. — A paper was read on the triple sulphurct of lead, copper, and antimony, discovered by count Bournon in Cornwall. Mr. Jameson proposed to call this mineral Bour- nonite; but the count, in this additional memoir, in which lie corrects the mistakes he made respecting the figure of its Crystals in a former paper, prefers the name of the place where it was found. The integral molecule of this mineral pe has determined not to be a perfect cube, as at first con- cluded, but having dissimilar sides in the proportion of 3 to 5. The count, in answer to a paper of Mr. Smithson in the Philosophical Transactions, defends the existence, not only or binary but also of ternary and quaternary compounds, and proves that the mineral in question is an example of the latter combination, a quaternary sulphuret. As an instance of the very singular difference in minerals in consequence of this variety of combination, the count refers to the anhy- drous sulphat of lime, which is so very different from com- mon gypsum, although composed o'f the same materials with the addition only of a little water.
May 10. — A paper by Mr, Home, on the Squalus vnaximys, was read, stating some particulars of the dimen- sions and conformation of the different basking sharks which have been thrown on the coast of Britain in tlie course of the last year. The author considers this species of shark as occupying an intermediate place between the mammalia (whales) and fishes, and partaking of the characters of both.
May 18, — Capt. Burney stated to the Society some more particulars respecting the floating of heavy bodies in a stream, and the nature of their moving faster than the cur- rent. He seemed to consider the cause of all such motion to be owing to the pressure of the atmosphere.
Mr. Cavendish laid a paper before the Society on the me- thods of dividing mathematical instruments, in which he proposed to substitute a balance compass and microscope for Mr. Troughton's cylindrical ruler. 7"he plan was illustrated by a drawing of the instrument, which effected the purpose , without
Society of Arts, A&tpkt. — Wernerian Society. 409
without the necessity or risk of calculations, which almost always involve errors.
A part of a letter from Dr. Henry to Mr. Davy, on ox- ygen of ammonia when exposed to electrization, was read. By some recent experiments Dr. H. has ascertained, that m decomposing the ammonia, some oxygen was admitted in the process, and that consequently^what wa3 found as the result of Ins former experiments was not derived from the ammonia by electrization, but from the agents employed. The final result, however, of his experiments proved that ammonia, as Mr. Davy originally concluded, is composed ofoxvgen, hydrogen, and nitrogen.
The Society then adjourned over one Thursday on account of the holidays.
SOCIETY OF ARTS, ADEtPHl.
At a late meeting of this Society, a communication from Mr. R. Porrett jun. wp.s read, announcing that he suc- ceeded in obtaining prussous (or sub-prussie) acid — an ac.i differing from prussic, as sulphurous does from sulphuric acid, by containing less oxygen. It is a most delicate test of the presence of silver in solution, and has the singular property of precipitating iron of a red colour. It has completely- proved the presence of oxygen in prussic acid ; as by de- oxv^enating the latter it becomes prussous acid ; and oa adding oxygen, it is again capable of affording a blue preci- pitate of iron.
A new process for hardening the surface of casts in plan- ter of Pari^ has been communicated to the same Society. It consists in boiling the cast in a solution of one pound of alum in a pint of water for 15 minutes, and then suffering it to dry gradually for about a month ; in this way the cast acquires a very considerable degree of hardness upon its sur- face, and is even capable of receiving a polish by friction, so as to resemble white marble ; and the surface of it may be cleaned from lime to lime, without the Jea^t injury to the sharpness of the cast.
WERNERIAN NATURAL HISTORY SOCIETY.
At the meeting of this Society on the 8th ol April, there was read the first part oi' a Description oi the Mineral Strati
of
410 Wernerian Natural History Society,
of Clackmananshire, from the bed of the river Forth to the base of. the Ochils, illustrated by a voluminous and very distinct plan or section of those strata, done from actual survey, and from the register of the borings and workings for coal in Mr. Ersktne of Mar's estate in that district; communicated by Mr. Robert Bald, civil engineer, Alloa. In this first part Mr. Bald treated only of the alluvial strata* In continuing the subject, he is to illustrate it still further by exhibiting specimens of the rocks themselves.
Mr. Charles Stewart laid before the Society a list of insects found by him in the neighbourhood of P^dinburgh, with in- troductory remarks on the study of entomology. It would appear that the neighbourhood of Edinburgh affords no very peculiar insects, and but few rare ones. The list contained about 400 species ; which, Mr. Stewart stated, must be considered as the most common, as they were collected in the course of two seasons only, and without very favourable opportunities. It was produced (he added) merely as an incitement to younger and more zealous entomologists,
At this meeting there were laid on the Society's table the first two volumes 4to, with a volume of figures, of Comte de Bournon's System of Mineralogy ; presented by the author.
At a meeting of this Society on the 13th of May, the second part of Mr. Bald's interesting mineralogical descrip- tion of Clackmananshire was read, giving a particular ac- count of two. very remarkable slips or shifts in the strata, near 1000 feet in depth, and by means of which the main coal field of the country is divided into three fields, on all of which extensive collieries have been erected.
The Rev. Mr. Fleming, of Bressay, laid before the So- ciety an outline of the Flora of Linlithgowshire, specifying only such plants as are omitted by Mr. tightfoot, or are marked as uncommon by Dr. Smith. This, he stated, was to be considered as the first of a series of communications illustrative of the natural history of his native country.
Mr. P. Walker stated a curious fact in the history of the common eel. A number of eels, old and young, were found in a subterranean pool at the bottom of an old qua.rrv, which
had
Manchester Philosophical Sotlety. 411
had been filled up, and its surface ploughed and cropped, for above a dozen of years past.
The secretary read a letter from the Rev. Mr. Maclean, of Small Isles, mentioning the appearance of a vast Sea Snake, between 70 and 80 feet long, among the Hebrides, in June 1808.
And he produced a list of about 100 herbaceous plants, and 200 cryptogamia, found in the King's Park, Edinburgh, and not enumerated in Mr. Yalden's catalogue of plants growing there ; communicated by Mr. G. Don, of Forfar, late superintendant of the Royal Botanic Garden at Edin- burgh.
MANCHESTER PHILOSOPHICAL SOCIETY.
We copy from a Manchester newspaper the following Resolutions, which were occasioned (as appears from the advertisement containing them) by some extraordinary cir- cumstances, that have lately occurred in the Literary and Philosophical Society of that place. They were passed una- nimously at a meeting of the Society, which was held on the 5th instant, in consequence of a special requisition ; and which was attended by a greater number of members than had ever been assembled on any former occasion ; consistently with the spirit of them, Mr. Henry was re-instated in the office of president on the 12th instant. — -
" At an extraordinary meeting of the Literary and Phi- losophical Society of Manchester, held on Friday, May 5, I8O9, in consequence of a special requisition signed by twenty-nine members, it was resolved unanimously,
*( 1st. That the thanks of this meeting are due to Mr. Henry, for his long and valuable services, and for his uni- form exertions to promote the best interests of the institu- tion ,
" 2dly. That the circumstances of Mr. Henry's age, and standing in the Society, the great respectability of his cha- racter, his valuable contributions to the Society's Memoirs, and the rank which he has long held in the scientific world, peculiarly distinguish him as a fit person to HI] the chair of this Society.
*f 3dly. That a deputation be. "appointed to wait upon Mr.
Henry,
4 1 2 Stony hurst Scientific Establishment, — Smyrna Madder. W. i\ , to communicate, in the most respectful manner, the sentiments expressed in the two foregoing resolutions."
STONYHURST SCIENTIFIC ESTABLISHMENT.
When the French entered Liege, the gentlemen of the seminary at that place were forced to make a precipitate re- treat, abandoning a large establishment, together with a valuable library and a fine collection of mathematical instru- ments. Having since found an asylum in this country, they have formed an establishment at Stonyhurst, where they are making a laudable attempt to introduce the sciences, in their improved state, into their common course of education. As a first step, a handsome room for a library and another for mathematical apparatus have been built, to which it is in- tended to add a chemical laboratory as soon as possible.
As the arrangements of the building appear to us to unite much in a small space, we are happy in being enabled to present our readers with an engraving of the ground plan, (see Plate XII.) which may prove useful to those who pro- ject similar establishments.
It is not doubted that the gentlemen at Stonyhurst will not only be soon enabled to finish the erection of their bud 'hug, but to procure the books and instruments neces- sary to the perfecting of their undertaking — a very liberal subscription having been procured among the friends to their establishment.
Among other respectable names in the list of contributors we observe the duke of Northumberland's for 100/. ; the marquis of Buckingham subscribes 5oL, the earl of St. Vincent bi)L, and the earl of Moira 50/., Sec. &c.
LXXIII. Intelligence and Miscellaneous Articles.
SMYRNA MADDER.
This valuable plant has lately been introduced into this country by Mr. Spencer Smith, who furnished the Society of Arts, &cc. &c, with some seed, from which Mr. Salis- bury of the Botanic Garden, Cadogan Place, Sloane Street, has been so fortunate as to obtain plants, which have grown
in
Lectures, 4 1 3
in a most promising manner. He expects to obtain seed from them, and by their cultivation hopes may now be en- tertained that this most valuable dye-root will become na- turalized to our soil.
LECTURES.
Mr. Brookes's Summer Course of Lectures on Anatomy,
•Physiology, and Surgery, will commence on Saturday the
10th of June, 1809, at Seven o'Clock in the Morning, at the
Theatre of Anatomy, Blenheim-Street, Great Marlborough-
Street.
Surgeons in the Army and Navy may be assisted in re- newing their Anatomical Knowledge, and every possible Attention will be paid to their Accommodation as well as Instruction.
Anatomical Converzationes will be held weekly, when the different Subjects treated of will be discussed familiarly, and the Students' views forwarded — To these none but Pu- pils can be admitted.
Spacious Apartments, thoroughly ventilated, and replete with every Convenience, are open at Five o'Clock in the looming, for the purposes of Dissecting and Injecting, where Mr. Brookes attends to direct the Students, and de- monstrate the various Parts as they appear on Dissection.
An extensive Museum, containing Preparations illustra- tive of every Part of the Human Body, and its Diseases, appertains to this Theatre, to which Students will have oc- casional Admittance — Gentlemen inclined to support this School by contributing preternatural or morbid Parts, Subjects in Natural History, &c, (individually of little value to the Possessors) may have the pleasure of seeing them preserved, arranged, and registered, with the Names of the Donors.
TERMS. £. s. d.
For a Course of Lectures, including the Dissections, 5 5 & For a Perpetual Pupil to the Lectures and Dissections, 10 10 0
The Inconveniences usually attending Anatomical Investi- gations are counteracted by an antiseptic Process. Pupils mav be accommodated in the House. Gentlemen established in Practice, desirous of renewing their Anatomical Know- ledge, may be accommodated with an Apartment to Dissect in privately.
Mr. Taunton
414 List of Patents for Kew Inventions.
Mr. Taunton will commence his Summer Course of Lec- tures on Anatomy, Physiology, Pathology, and Surgerv, otl Saturday the 3d of June, 1809, at Eight o'CIock in the Evening precisely. They will be continued every Tuesday, Thursday, and Saturday, at the same hour. Particulars may be had on applying to Mr. Taunton, Grevdle-Street, Hatton- Garden.
LIST OF PATENTS FOR NEW INVENTIONS.
To Simeon Thompson, of Maddox Street, Hanover Square, for a machine or machinery for raising, lowering^ drawing, driving, forcing, impressing, or moving bodies* substances, materials, fluids, articles, or commodities.-^ March 20, 1809.
To Charles Valentine, of the parish of St. James, Clerk - enwell, japanner, for a new mode of ornamenting and paint- ing all kinds of japanned and varnished wares of metal, wood, paper, or any other composition, and various other articles. — March 20.
To James Yonnie, of Theobalds Row, Middlesex, smith, for a machiue or instrument, to be applied to stoves or grates, for preventing accidents by fire ; and whereby the fires in stoves or grates may be put out and extinguished with safety and facility. — March 28.
To Elizabeth Perryman, of Greek Street, Soho, Middle- sex, for a new street and hall lamp, and the necessary ap- paratus for expediting the trimming, lighting, and cleansing the said street and hall lamp* — March 29.
To Richard Willcox, of the parish of St." Mary, Lambeth, Surrey, mechanist, for sundry apparatus or machinery for accelerating the manufacturing of felt or stuff hats ; and for cutting and removing by machinery the furs of beavers, rabbits, and the whole variety of skins, the furs or wool of which are used for the purpose of hat-making.— ^-April 3.
To Richard Willcox, of the parish of St. Mary, Lambeth, Surrey, for certain machinery for facilitating the manufac- turing of stuff, wool, and other hats, and bonnets felted. — April 3.
To John Thomas Groves, of Great Scotland Yard, White- hall,
List of Patents for Neiu 'Inventions. 415
hall, Middlesex, esq., for an improved mode of construct- ing buildings, by which great expense, labour, and time, is saved, and the buildings -secured from dry rot, with other advantages. — April 3.
To John Frederick Archbold, of Great Charlotte Street, Surrey, gent., for a method of converting salt or sea water into fresh water, both on land and on board of ship at sea. —April 18.
To William Pleasants the elder, of Abbey Street, in the city of Dublin, bachelor of arts, for a self-mover, or ma- chine which can keep itself in motion. — April 19,
To Phillips London the elder, and Phillips London the younger, of the parish of St. Luke, Chelsea, Middlesex, gents., for certain new and improved methods or processes of manufacturing, refining, and purifying muriate of soda or common salt. — April 19.
To Phillis Bown Thomason, wife of Edward Thomason, of Birmingham, manufacturer, for improvements in the making of umbrellas and parasols. — April 19.
To Matthias Wilks, of Brabant Court, in the city of London, merchant, for his compound substance or cake for the feeding of horses and other animals. — April 20.
To John Barton, of the town of Tunbridge, in the county of Kent, gent., for his machine for raising weights or water with greater facility and at less expense than any at present used. — April 25.
To Richard Trevithick, of Rotherhithe, in the county of Surrey, engineer, and Robert Dickinson, of Great Queen- Street, in the county of Middlesex, esq., for certain inven- tions calculated to improve naval architecture and naviga- tion, and to contribute to the comfort and better subsistence of mariners. — April 29.
To William Hamilton, of Lower Mount-Street, in the city of Dublin, for his new mode of preparing soda and other mineral waters, spirituous, acetous, saccharine, aromatic liquors, and sundry improvements relative thereto. — May 4.
METEOItO-
416
ZleieorvJogy, meteorological table, By Mh. Carey, of the Str. For May 1809.
WD,
Days of the Month.
Thermometer.
Pi
Height of tne Barom.
Inches.
Weather.
April 27
28
29
30
Mav
e
7
6 9 10 II 12 13 14 15 16 17 18 19
20 21
22 23 24 25 £6
49°
48
40
42 4 7 4 2
40 45 4§
45 51
57 54 53 57 57 58 61 61 60 63 66 67
58 55 53 55 51 50 51
52°
55
45
52
52
51
52 56 55 59 65 65 66 67 62 72 73 74 64 73 73 75 75
65 59 66 75 67 61 66
47°
40
38
4S
44
40
42 49 43 49 57 51 51 54 57 57 60 62 56 61 62 63 55
54 51 56 5!
50 52 55
29'60 •46 •82 •69 "27 •53
•80
•90
30*02
•28
•34
•29
•14
•05
29*99
3000
29*91
•89
•80
•78
•85
•75
•52
•78
'90
30* I 3
•17 •16
•02 2Q-82
— t—
39 10 51 55 10 14
60 10 80 65
65 75 76 81
95 82 79 70 40 78 80 75 46
36 39 67 63 75 44 34
Cloudy
Rain
Cloudy
Fair
Rain
Showerv with
thunder Fair Cloudy Fair Fair Fair Fair Fair Fair Fair Fair Fair Fair
Showery Fair Fair Fair Showery with
thunder Cloudy Cloudy Fail- Fair Fair Cloudy Cloudy
N. B. The Barometer's height is taken at one o'clock.
t 417 ]
LXXlV. Thoughts on Atmospheric Density and Pressure. By Thomas Charlton Speer, Esq.
To Mr. Til loch, — Sir, -LNotwith standing the wide field of inquiry which the mechanical history of the atmosphere presents to us, and notwithstanding the interest which such inquiry must na- turally excite in a philosophic mind, yet we must confess, our labours in it have been but partial, and our knowledge of it is but limited : — the attention of men of science has (comparatively speaking) been mostly confined to its che- mical history, probably from its more immediate connection with, and relation to, practical and useful results. On the former subject, therefore, I beg to offer some ideas' which have suggested themselves to me, and which relate to one of its principal (though I think least understood) properties.
Unaided by the lights of natural philosophy or the force of experiment, it scarcely comes within the limits of human conception, that that invisible inodorous aeriform mass of fluid surrounding our globe should at all be subject to the laws or possess the properties of matter; but particularly that it should possess either density, weight, or pressure.
These three properties of atmospheric air, viz., density, weighty and pressure, are often misunderstood, and gene- rally confounded with each other, particularly the two former. Now we well know that attraction of cohesion and attraction of gravitation sensibly differ from each other; if not, platina would be the hardest, and the diamond the heaviest, bodies in nature. We know that their action is quite "different, that of the one being inversely as the squares of the distances, that of the other increasing at a much quicker rate as bodies approach* the smaller the distance the greater its power. By the word density therefore, (which in parti- cular seems often misapplied and misunderstood.) I mean, strictly speaking, impermeability, or that power in a body by which it is enabled to resist or obstruct (more of less) the passage of other bodies through it, and which may be esti- mated by the greater or less difficulty with which such re- sistance or obstruction is conquered. Now this impenne- Vol. 33, No>r 134, June 1809. Dd ability
418 On Atmospheric Density and Pressure.
ability in a body must arise not only from the closeness with which its integrant parts are connected, but also from the weight of these parts, and consequently the difficulty of removing them ; so that, in other words, density, I think, may be defined, that power resulting from the union of the attraction of cohesion and gravitation.
That the atmosphere is possessed of this power is well known: — take two bodies of different - weights but equal bulks, drop them from the same height, it will be found that the differences of their velocity in descent will be di- rectly as the differences of their weights, and as the dif- ferences of the times of their descent, and that consequently the spaces of atmosphere descended are directly as the squares of the times, and as the squares of their velocity in falling. To this it may be answered, that gravity is the sole cause, and that the air has no effect whatever : however, that this is not the case is well known by the old experiment of a feather and guinea falling alike in the exhausted receiver of an air-pump. Hence, were it not for the greater or less re- sistance or impermeability of the atmosphere, the force of gravitation would be equal in bodies; their absolute gravity depends, more or less, on the density of the atmosphere, not the latter on the former.
Now -it is obvious that this power can only exist where there are particles or molecules (see Boscovich) : it must depend on the disposition of those particles, and even on the particles of those particles to the ultimate one, viz., on their size, their shape, form, &c., and their degree of aggregation and consequent distance from each other. At- mospheric air, therefore, must have its particles or mole- cules, (though completely imperceptible to our organs of ■sensation,) certainly, from its great permeability, its yielding to the slightest impression, and affording little or no resist- ance to the insinuation of bodies denser between the in- terstices of its particles : this power in atmospheric air may almost be said to be at its minimum.
This permeability in atmospheric airarises, it is supposed, from the very slight aggregation of its particles, and conse- quently their small quantity and great distance from each
other: —
On Atmospheric Density and Pressure. 4t<J
rjther : — however, this may not be the case ; \t (the atmo- sphere) may contain many particles, and these particles closely approximated together by a strong cohesive force ; but this permeability may arise from their extreme minute- ness and want of gravity, from their spherical form, (their angles being blunted off by friction,) and their thus sliding through, among, and under each other, yielding to, and being impelled by every motion communicated. Indeed the latter hypothesis, I think, seems the more probable. How- ever, from whatever cause it is, a degree of tenuity or permeability arises which scarcely any other body possesses^ and which may be estimated by the velocity with which heat, light and sound travel through it.
Atmospheric density is generally confounded with atmo- spheric pressure, though distinct from each other; the one is a property it possesses in common with all other bodies, the other is peculiar to itself alone. In the one there ap- pears an inherent and self-existent direction of the particles, and this direction seems positive and determinate ; in the other there appears no direction but what is given by exter- nal and accidental causes, and therefore quite vague and indeterminate, and only what is possessed by all matter. Atmospheric pressure may be shown in various ways, per- haps one of the simplest is thus :-— invert over a bason of water, a tumbler previously exhausted of its air; the water of the bason will ascend in the tumbler much higher (ac- cording to the dimensions of its column) than its level in the basort, — being pressed down by the external atmosphere^ its particles are forced to cohere closer together, until the force of pressure is withdrawn ; they then recede from each other, the interstices between them are'increased, and thus taking up a greater space, they consequently ascend, being prevented by the sides of the tumbler from expanding la- terally.
Now surely it is inconceivable trfat a body weighing only the eight or nine hundredth part that of another, could pos- sess the power of raising it up, and consequently forcing it to assume a contrary direction to that gravitating one which it, though in so alight a degree, possesses in common with
D d 2 other
♦20 0?h Atmospheric Density and Pressure,
other bodies, were it not for a self-impelling self-existing force in the atmosphere. For instance, were the experiment tried under a fluid still heavier than air, but lighter than water (oil for example), in a vacuum, Quere, Will not the •water remain level inside and outside?
Hence we must argue, that pressure is distinct from den- sity, self-existing in the atmosphere, and in that alone; nor even do they always act directly of each other, particu- larly in the upper regions of the atmosphere. (See Bouguer's Travels &c. in the Andes.) However, although they do not appear to be one and the same power, yet they seem intimately connected, and to act directly with each other, and what affects the one affects the other.
Galilei was the iirst discoverer of atmospheric pressure, by observing that fluids rose to a certain height in a vacuum, which had formerly been accounted for by the old idea of W Nature abhorring a vacat^m,*'
Torricelli, his pupil, completed the discovery*, observing that the atmosphere pressed equally on all bodies' at the earth's surface, and in proportion to their densities; viz., more on a fluid than a solid, and more on a gas than either: and as fluids are of different densities, and the only bodies susceptible of being acted on by this pressure, from the slight cohesion and consequent motion of their parts, he natural! v conceived that the rarer the fluid the higher it would rise in a vacuum, and vice i>et\sa.
Thus, he first found that water, at the medium tempera- ture of the atmosphere, would ascend about 32 feet, con- sidering this the rarest fluid, which height or column of 32 feet was consequently an equipoise to a column as high as the atmosphere: — calculating the comparative densities of fluids, he conceived that one twice as dense as water would ascend half as high, and so on, the density of the fluid being inversely as the height of its ascent. Then, considering the comparative densitv of water, the rarest, with that of mer- cury, the densest fluid known, he found it to be 14*1 ; con-
• After Torricelli, Pascal brought this discovery to still further perfection, and made many important additions, particularly by his celebrated experi- ments on the Puy dc Dome.
sequent!/,
On Atmospheric Density and Pressure, 421
sequcntly lie concluded that the mercury would rise^th the height of the water : this he found exactly to answer. He filled a glass tube about three feet long, closed at one end and exhausted of its air, and inverted it into a bason of mercury ; the mercury rose £9 inches, = T^th the height of the column of water ; the remaining part of the tube was of course a vacuum (the Torricellian vacuum).
This mercurial column 29 inches high, is therefore equal to a column of the atmosphere extending from its summit to the earth.
The atmosphere presses equally on all bodies at the surface of the earth, or equally distant from it.
This pressure decreases in a direct ratio (generally) with, its distance upwards from the earth's surface, (the atmo- spheric column being shortened,) or rather from the level of the sea, it being the only natural uniform level from whence such indications are deducible. Hence it follows, that it increases directly with its distance downwards from such level — (the atmospheric column being lengthened) — so that in pits the pressure must (comparatively speaking) be at its maximum : of this, however, I believe we have no direct proofs.
Thus the atmosphere may be said to constitute a mass consisting of strata lying on each other, each stratum pressing on the one next it with not only its own individual weight, but with that collected weight with which it is pressed from above, so that the lower stratum has the whole superjacent pressure as it were on its back, and with it presses the earth.
Hence (supposing the ratio to be direct), if heights in the atmosphere be taken in arithmetical proportion, its rarity (from want of pressure) will be in geometrical progression ; thus, at 7 miles above the earth it is 1 times rarer, at 14 miles it is 16 times rarer, at 21 miles it is 64 times rarer, and so on, the rarity increasing in proportion to the height as 4M.
This principle of the atmosphere decreasing in pressure as we ascend, and this decrease being (generally) equable,
Pd3 has
422 On Atmospheric Density and Pressure.
has been most happily applied in the estimation of altitudes (particularly those of mountains) by theTorricellian tube, or, as it is more commonly called, the barometer*. The mer- curial column decreasing as we ascend, the column of air decreasing in" height, and of course decreasing in its ability to support the former; at that height therefore at which the mercury would no more rise but remain in its bed, the pres- sure must either be at its limits, or too slight to raise so dense a body as mercury : but if a rarer fluid were employed at this height, the force of pressure might still perhaps sen- sibly act on it until that period, when, from the want of both density- and pressure in the air, its particles could no longer keep together, and a vacuum must ensue : indeed this I think (if possible) the only^true mode of ascertaining the height of the atmosphere, because where there is atmo- sphere there will be pressure also.
However, the barometer does not appear calculated for estimating great heights in the atmosphere, because there, as was said before, its decrease of density does not often keep pace with its decrease of pressure or gravity, as appears from the observations of Bouguer and Don Ulloa, &c. on the Andes, the upper regions being (from various causes) not subject to the same laws as the lower ones. Hence, as in the common indications of a barometer, the pressure, weight, and density are more or less connected with each other,, though in reality, and strictly speaking, distinct, as before mentioned: consequently the equability of its ascension must, at these high regions, be considerably diminished, from these three powers being more or less at variance with each other, and therefore its indications must \>t erroneous. If the ratio of the mercury's descent for our ascent were known, and was equable, the barometer might ascertain any height, and we might easily know that at which it would remain at its level.
In the lower regions (the heights of mountains for in- stance) the mercury, it is said, generally falls an inch
* Barometer, however, in strictness, means a measurer of the weight of the air.
for
On Atmospheric Density and Pressure. 423
for 850 or 900 feet at a medium* : it' this ratio held good altogether, the mercury must remain in its bed at the height of 27000 feet.
As a square inch column of mercury 30 inches higlr (which various observations and experiments have proved to be the medium pressure in those countries, or others situated in or near their latitudes,) weighs about ljlbs., so the at- mosphere must press with a weight equal to 15lbs. on every square inch, or 180ibs. on each square foot: calculating thus, the whole superincumbent pressure of the atmosphere amounts to 12,043,44 8,800,000, 000,000lbs.f Reckoning the surface of a man's body to be about 14 square feet, he sustains a pressure (calculating thus) of 1 1 tons 2 hundred weight 18}lbs.
It mav be wondered how man could bear such a weight on his body and not be crushed. On the contrary, this pres- sure is indispensably necessary to our existence, and two reasons concur in preventing its being felt troublesome : 1st, its being so equal all over our bodies as not to move their fibres; 2dly, the caloric generally evolving from hence counteracts and renders it less sensible. Besides, sensations we have been accustomed to from our birth do not much annoy us, and it is probably this pressure that occasions the cries of the new-born babe.
Atmospheric pressure is necessary to our existence. In ascending into the air, we might suppose our sensations would be more agreeable by being loosed as it were from a heavy load : yet the contrary is the fact ; the blood of our internal vessels not being pressed down, bursts and over- flows its barriers, insomuch as sometimes to endanger death.
These sensations are always perceived in ascending con- siderable heights : spitting of blood, and bleeding at the nose and eyes, a drowsiness, listless apathy, and inexertion are
* This appears from the observations and experiments of Saussure and De Luc on the Alps, Don Ulloa, i'ouguer and Condamine on the Andes, and of Mr. Kirvvan on mountains in Ireland ; all of whose labours "in this interesting subject, besides those of Dr. Hailey, Sir George Shuckburgh, and General Roy, have so much contributed to its advancement.
f Equal to a ball of lead 60 miles in diameter. See Coles's Lectures.
D d 4 expe-
42i On Atmospheric Density and Pressure.
^experienced*. Hence Providence has wisely ordered it, that this pressure, though apparently such a load on us, should be absolutely necessary to our lives, by keeping our blood within its proper limits, making its particles retain their proper cohesion, and thus giving the pulse, heart, &c, that uniform gradation of beating in which the vital principle consists.
Atmospheric pressure varies considerably, (as was before observed,) particularly in the upper regions, and these varia- tions appear to increase as we ascend into them ; because the decrease of density not keeping pace with the decrease of pressure, there must, in those high regions, be sudden condensations and rarefactions, which must divert from their direction the pressing down particles of the atmosphere, and drive them laterally and otherwise, &c. Hence the secon- dary cause that affects these variations is the winds : 011 this account these variations are greatest at the poles, and de- crease towards the equator, there being greater winds at the former, the atmosphere there being denser from its less high state : that they are little or none at the equator, has often been proved.
Were it not for atmospheric pressure there would be but little distinction between liquids and gases, no more than what is produced by the action of that aggregate attraction on the one hand, and that quantity of caloric on the other, with which they are naturally endued. For, as the pressure always assists cohesion, and consequently counteracts the effect of caloric ; and as the particles of bodies have liberty to move and recede from each other directly as the positive and repelling power, and inversely as the negative and ap- proximating one, viz., cohesion ; and as between these con- stituent internal powers all bodies are balanced ; it follows, that when a third neutral external power is introduced, viz., pressure, it must turn the scale, weaken the action of the caloric, and tend to keep the body in a liquid state ac- cording to its force. Hence the quantity or degree of heat
* Messrs. Humboldt and Bonpland perceived these symptoms to a verv alarming degrcee on the Cordilleras : even Dr. Pitcairn in ascending Ar- thur's Seat (only 900 feet) began to be sensibly affected so.
necessary
On Atmospheric Density and Pressure. 425
necessary to produce the conversion of a liquid into a ga$ (of evaporation) must depend on the pressure of the air; the greater the pressure, the greater the heat necessary from its greater resistance to its escape, and vice versa.
Thus, in the application of a heat (nearly boiling) to a fluid, its particle.-> being rendered so rare and min :tu acquire a disposition to ascend, from want of gravity. In this dis- position to ascend they come into contact with the particles of the air pressing downwards, and are thrown down again, their force of ascent being inferior to the force of descent possessed by the atmospheric particles. The body is there- fore still kept liquid in this degree of heat: if, however, it is increased a little further, the particles are forced to rise up and conquer the force of pressure, and thus evaporation takes place.
In this state then a body is balanced between three powers, two of which may be said to be quiescent, and the third divelle7it; if the united sum of the quiescent forces, pressure and cohesion, amounts to more than the divellent caloric, its liquidity remains; if less, evaporation ensues.
Then, in a case of evaporation, to know the force or power with which it takes place, add the sums of the quiescent powers, cohesion and pressure, (numerically expressed,) de- duct their united amount from the sum of the divellent ca- loric, and the remainder wUl be the sum required. Thus, suppose a body possessed with the three powers so, the qui- escent A and B, and the divellent C, thus A with the force of 6, B with the force of 2, and C with the force of io, then we have A6+ B c2 = 8 — C 10 = 2, the force with which the body evaporates. If the forces are equal, and that there is no remainder, the body of course will remain as it is.
On the other hand, in the reconversion of a gas into a liquid (or condensation) where the powers are reversed, to know the force with which the body condenses, subtract -the quiescent caloric from the united sum of the divellents, pressure and cohesion, the remainder is the sum required. 'J nus, suppose a body with the powers to C, caloric with the force of G, B pressure with the force of 8, and A cohe^i'.n
with
426 On Geometrical Proportion.
with that of 2, then we have C6-B8 + A2= 10 = 4. The body therefore condenses with the force of 4. Thus then, by numerical expression, we find the conversion of liquids into gases, and vice versa; and hence this conversion depends more or less on atmospheric pressure.
Although the force of pressure is too slight to affect solids, yet crystallization is in a certain degree dependent on it ; the cohesive power in the liquid would not be sufficient of itself.
Hence, though the points of condensation and evapora- tion are established at certain standards, it is merely because the pressure is similarly established at a certain standard point (30 inches). The boiling point of water at this pres- sure is 212°. On the tops of mountains a much less degree of heat will suffice*, and in an exhausted receiver it will boil at 70\
On the contrary, when the pressure is increased (in pits or mines), a greater heat is of course required, and by arti- ficial pressure water may almost sustain any heat without evaporating f. The exact ratio of the decrease of heat for the decrease of pressure, or the increase of heat for the in- crease of pressure, in the process of ebullition in water or other fluids, has not, I believe, been hitherto determined.
Thos. Charlton Speer.
May 19, 1809.
LXXV. On Geometrical Proportion. By Wm. Marrat, Esq., of Boston, Lincolnshire.
To Mr. Tilloch, — Sir, JL he doctrine of proportion is well known to be of so much importance to mankind in general, that any attempt to elu- cidate its principles cannot be deemed entirely useless. A great part of the obscurity with which this subject is enve- loped, arises from the vague and ambiguous manner in
* See Saussure, on the Alps, Sec
+ Hence, bv means of an instrument that would very sensibly measure the degrees of heat, we might (ceteris paribus) ascertain heights in the atmo- sphere, and our distance above it, by the decrease of the boiling point ; and, on the other hand, Our distance below it (in pits for instance) by its increase.
which
On Geometrical Proportion. 427
which authors have defined the word proportion: thus, it is frequently confounded with the words ratio, reason, ana- logy, &cc, and sometimes two, sometimes three, and some- Umzsfour quantities are said to be proportional. This mode of procedure creates a good deal of confusion, and not a little embarrasses the ideas of beginners ; and it is to obviate, in some measure, thes'e irregularities, that I now send you the following short disquisition on this interesting branch of science. I must observe further, that the manner which is generally practised by authors of treating the subject geo- metrically, as is done in Euclid's Elements, and most of the modern books of geometry, is certainly not the most eli-gible, or best adapted to learners ; and, except the few trifling observations which may be met with in books of arithmetic, it is to books of geometry alone to which a learner can have recourse for any information he may rt quire.
To prove that what I have advanced concerning the ob- scurity of the subject, when treated geometrically, is cor- rect, I need only appeal to those gentlemen- who are in the practice of teaching the fifth book of the Elements ; it is well known that the difficulties attending it are so great, that very few students ever thoroughly understand his demonr strations, owing most probably to their not being able to form a correct idea of his criterion of proportion. .Again, "Ordinary language (as Professor Playfair observes) con- veys the ideas of the different operations supposed to be per- formed by these demonstrations so slowly, and breaks them down into so many parts, that they make not a sufficient impressiqn on the understanding ; and this generally happens when the things treated of are not represented to the scn«cs by diagrams, as they cannot be when we reason concerning magnitudes in general, as in this part of the elements of ge- ometry. It is obvious, therefore, that we ought to adopt the language of arithmetic, or algebra, which by its short- ness, and the rapidity with which it places objects before us, makes up for its being a conventional language ; and also for using symbols to denote the things we wish them to express."
The first ideas of proportion which we generally acquire,
are obtained by comparing natural objects with one another:
3 thus,
4 £8 On Geometrical Proportion.
thus, we say one thing is twice, thrice, &c, as large as another, or one thing will cost twice, thrice, &c, as much as another : but, as our ideas expand, we wibh to compare all kinds of magnitudes as exactly as possible ; and then it is that a more ample view of the subject becomes necessary. Arithmetic instructs us how to compare any two quantities with each other, so as to determine fhe relation which sub- sists between them : this is the first notion which we ac- quire of proportion, and it is the foundation upon which we must raise our future reasonings : this comparison of any two quantities may be called a ratio, and hence we have the following
Definition I. — The word ratio signifies the relation which subsists between two quantities with respect to their magnitudes. One of the quantities thus compared is called the antecedent, the other the consequent of the ratio, and they are sometimes expressed by placing two points between them, or more frequently by writing them in the form of a frac-
3 tion : thus, 3 : 4, or-, is the manner in which we generally
designate the ratio of 3 to 4, and a : b, or j, denotes the
ratio of a. to b.
6 3 1
The ratio of 6 to 12, or — , is the same as - , or as ^ ;
1 & O It
hence it is plain that the terms of a ratio may vary, and the ratio still continue the same : if, therefore, the terms of a ratio be either multiplied or divided by the same quantity, the
a
ratio will not be altered; for :7 = 7 , and ~ — T = the
m
same ratio.
It will now be very easy to define the word proportion.
Definition II. — Four quantities are proportional when the ratio between the first and second is the same as the ratio between the third and fourth ; and, in general, any number of quantities are in the same proportion when they are com- posed of equal ratios.
Thus four quantities, a, bi c, d> are in the same pro- portion
On Geometrical Proportion. 420
CL C
portion when j = - ■., and any number of quantities, a> I, c,
CL C 6
d, e,f, &c, have the same proportion when j = 7 = -7. &c.
j
Hence we have a criterion by which proportional quan- tities may easily be distinguished, viz. an equality of ratios ; and this being understood, the whole doctrine of proportion flows immediately from the above obvious principles.
Four proportional quantities are commonly expressed by saying that a is to b as c to d, and they are usually written thus, a: b : : c : d; where Z>and a are called the mean terms, and a and d the extremes ; also a and c are called antece- dents, and b and d their consequents. The subject is further illustrated in the following articles :
Article I. — When four quantities are proportional, the product of the two means is equal to the product of the two
CL C
extremes. For since, by hypothesis, -,-= — , multiply both
sides of the equation by bd, and we have -j- =z-j}orad—bc.
Also, conversely, if the product of any two quantities be equal to the product of two others, the four quantities are proportional. For, since ad = be, divide by bd, and we . ad be a c
havc ld= M'orT=7; ^^a:b::c:d.
AriicleW. — If four quantities are proportional when taken
directly, they will be proportional when taken inversely ;
that is, \f a : b : : c : d, then will b : a : : d : c.
a, c For when a : b : : c : d, we have 7- = -j, and dividing
unity by each of these ratios, or inverting them, we ge|
h d i 1
- = -, or b : a : : a : c.
a c
Article III. — When four quantities are directly propor- tional, they will also be proportional when taken alternately ; that is, if a : b : : c : d, then will a : c : : b : a.
For, because y = -,-, multiply both sides by — , and we
la Ic a e . . . .
have , = v> or -«= 3 : that is, a ; c : : b : d, be dc re d '
430 On Geometrical Proportion.
Note. — Here, unless the four quantities are all of ttie same kind, the alternation cannot take place.
Article IV. — When four quantities are proportional, the first together with the second is, to the second, as the third together with the fourth is to the fourth; that is, when a : b : : c : d, a -f- b : b : : c -f d : d.
For, since = -j> add unity to each side, and -- -f- 1 =
c t » t • n . a + b
-7 + 13 and reducing each to an improper fraction, — . —
c + d = ~j—> that is, a -f b : b : : c -f d : d.
Article V. — When four quantities are proportional, the excess of the first above the second is, to the second, as the excess of the third above the fourth is to the fourth ; that is, when a : b : : c : d, a — b : b : : c — d : d.
— , . a c . a c a — h
ror. since -.- = -,-, we have -.- — 1 = — — i, or — \ — b a' b d b
c — d
= — — , that is, a — b : b : : c — d : d.
Article VT. — When four quantities are proportional, the sum of the first and second is, to their difference, as the sum of the third and fourth to their difference ; that is, when a : b : : c : d, then will a -{• b : a — b : : c + d : c — d.
■ For, by Art. IV., ^±* = c-±£ and by Art. V., £j2 =
£ d 4
; multiply both equations by b d, and d x (a + b) ss
b x (c + d), also d x (a — h) = b X {c — d), and if we
divide equals by equals, the quotients will be equal; therefore
dx(ai-l) bx(c+d) , . a+b c+d
— j yr as ; that is, 7 = ■ - , or a + b :
dx(a—/r) bx{c — d)' 3 a—b c — d '
a — i : : c + d : c - c?.
Article VI F. — When three quantities are proportional, the
first is, to the third, as the square of the first to the square
. a b of the second ; that is, if -.- as , or a : b : : I : c, then will is c J
a : c : : a1 : b\
For,
On Geometrical Proportion. 431
For, since y m — , we have ac = b2: multiply by <z, and
a a*
o?c = a b1 : or, = - bv Art. I., therefore a : c : : az : b1.
C V1 J
This proportion is often used in Dynamics.
Article VIII. — When any number of quantities are pro- portional, as one antecedent is to its consequent, so is the sum of all the antecedents to the sum of ail the consequents ;
cl c e that is, if a : b : : c : d : : e : f &c, or -.- = -.- = >-, &c,
then will a : b : : a + c + e : b + d + f
For, since r- = — = — , &c, we have ad = be, also
af=be, and by adding equals to equals, ad -J- af =
be -f- b e; add a b to both sides, and a b + ad -f- af = b a
-\- b c + b ey or a x (b + d -\-f) = b x (a + c + e); that is,
/ a t x a aJr c + e 7 i t
(Art. I.) j = f±j±j> or a : b \ : a -f- c + e : b + d +f.
Article IX. — When four quantities are proportional, any like powers or roots of these quantities will be proportional : that is/ if a : h ? i c : d, then will am : bm : : cm : dm ; where m may be either a whole number or a fraction.
„ . a c , _ am cm _
For, since -.- = -7, therefore ;— = -7^, or am : bm: : cm : a13.
Article X. — If the corresponding terms of two ranks of proportional quantities be multiplied together, their products will be proportional; that is, if a : b : : c : d,
and e:f::g:h, then will ae : If: : eg : dh.
CL C 6 S
For, since , = -., and --. -= y, multiply equalsby equals,
and „= S, or ae : bf : : eg : dh ; and the same is true for
any number of ranks of proportionals.
Article XI. — When four quantities are proportional, if the antecedents or consequents be multiplied or divided by . any quantity, the products or quotients will be proportional; that is, if a : b : : c : d, then will ma : mb : : ns : nd.
For.
43 S On the Benefit that may he expected.
ma nc
For v as -~ , therefore —. a= — „ or ma : ml : : ?zc : fti : 0 d' mb nd '
where m or n may be either whole numbers or fractions.
Article XII. — If there be four quantities, such that
a : b 1 1 c : dy and four others, such that c : d : : e :f, then
will a : b : : e :f.
For, since -7- = - ■ = - , therefore a : b : : e : f. o d J J
The above articles contain nearly all that is necessary to fee understood concerning proportional quantities ; and by students who know how to manage a simple equation in al- gebra, they will be read without much difficulty in a very short time. Not being ineumbered with equimultiples, the demonstrations are general, and will serve equally for either commensurable or uncommensurable quantities. Very little indeed of what I here send you can be said to be entirely new: it is presumed, however, that the principles on which the above demonstrations are founded, are laid down with more clearness and precision than in any author who has written on this subject. By inserting them in your valuable Miscellany, you will very much oblige your very humble servant, Wm. Maruat.
Boston, May 18, 1809.
LXXVI. A few Hints concerning the Benefit that may he t xpectpd from the Nature of Coal Gas*
To Mn. Tilloch,-— Sir, X hk gas which is obtained when coal is distil red in close
Is having lately attracted the attention of the public, chiefly on account of its application for the production of artificial light, has encouraged me to lay before your readers a few observations concerning this subject, which bids fair to be ranked among the most beneficial applica- tions of chemical science to the useful purposes of so- ciety. I will leave it to your judgement to abridge of these lines, or to cancel, whatever you deem unworthy of notice, to make room in your journal for more valuable subject*
yot
froih the Nature of Coal Gas, 43d
you may have received from other quarters. The brilliancy of the light which is produced tftfrifig the combustion of coal gas, is so superior in splendour and beauty, that it sur- passes not only wax candles and the best spermaceti oil, but every other substance hitherto employed for artificial illumination. The coke obtained in the same process is no valuable, that it appears inexplicable that men should not avail themselves of th*; mode of procuring %ht, to the almost total exclusion of all other methods now W mo. As a landholder, placed among an industrious but 'wholly il- literate society of men, ! have had the more opportunity of trying this species of fuel' or Coke, which I' coiul not otherwise procure in this sequestered spot, at a felen cheap rate, for purposes to which it has not, as far as I know, been hitherto employed. I must tell you that I am my own lime-burner, plaster (of Paris) baker, arid brick- maker ; and that in these proeesscs of rural ceconomy I have derived the greatest benefits from this species' of fuel, which I now prepare at a cheap rate, although I waste almost the whole of the light of the cual gas intentionally. The coal which I employed formerly for the burning of Jimestone into lime is a very inferior kind of small coal, called here Welsh culm', the only kind of limestone I can command is the gray kind, which strongly effervesces with acids. It readily splits into distinct layers, and becomes perfectly white after haying been exposed to a red heat. The kiln for burning it into lime is a cup-shaped concavhv, surrounded with solid brick -work, open at the top, and terminating below by an iron grate. It has a stone door that may be opened and closed for charging and emptying the furnace when required. This furnace' I formerly charged with alternate strata or layers of small coal and limestone, the latter being broken previously into pieces not larger than a man's fist, QWtil the kiln was completely filled. The stone is thus slowly decomposed; the upper part of the charge descends, and when it has arrived at the bottom of the furnace new strata are super-imposed, so as to ketp the furnace continually full during a period of 50 hours. The Quantity of lime I thus procured with small coal formerly Vol. 33. No. 134. June 1609. E ©* amounted
434 On the Benefits that may he expected
amounted to 85 bushels. The strata of coal necessary for the production of this quantity of lime require to be four inches thick, and the time absolutely necessary for the prob- ers* of calcination was, as stated already, *>0 hours. On applying coke instead of coal, (which coke I obtained from the same kind of coal,) the produce of lime may be increased to nearly 30 per cent, from the same furnace, and the time required to etTect the calcination of this quantity of lime- stone is reduced to 39 hours : it also requires less attendance and less labour, and the whole saving thus accomplished amounts to more than 50 per cent, on the lime-kiln. I have lately also employed coke for the burning of bricks. My bricks are burnt in clamps made of bricks themselves. The place for the fuel, or fire-place, is perpendicular, about three feet high. The flues are formed by gathering or arch- ing the bricks over, so as to leave a space between each of a brick's breadth; and as the whole of the coal, if this fuel be employed, must, on account of the construction of the pile, be put in at once, the charge of the bricks is not, and never can be, burnt properly throughout; and the inter- ference of the legislature with regard to the measurement of the clamp is a sufficient inducement for the manufacturer, to allow no more place for coal than he can possibly spare: — . the reason is obvious. If coke be applied instead of coal, the arches or empty spaces in the clamp or pile, as well as the strata of the fuel, may be considerably smaller: the heat produced in this case is more uniform and more intense, and a saving of 32 per cent, at least is gained. In the baking of my own plaster stone (the compact sulphate of lime of a reddish tinge) I also employ coke. The calcination of this stone for manure I perform in a common reverberatory furnace, and the men who conduct the process (who are otherwise averse to every thing new) are much pleased with the steadiness of the fire, and little attendance which the, process requires, when coke is used instead of coal. These are the few facts I wish to state to you, with regard to the- useful application of this species of fuel, which, no doubt, hereafter will become an object of ceconomy of incalcu' advantage to individuals,- if its nature be better understood 2 (tea
from the Nature of Coal Gas. 433
than it is now. In reading the ingenious observations of Mr. Accum * with regard to this subject, who states that the effects of different kinds of fuel may be learnt from the time required to heat a given quantity of water, &c, the determining, from the quantity of fuel consumed, the ceco- nomical application of different sorts of combustible matters, to ascertain the cost of the one when compared with the cost of the other, particularly arrested my attention with regard to the ceconomicai application of coke, when com-, pared with fuel of other kinds now in use.
ft will not, I am persuaded, be regarded as indicating a wish to detract in the smallest degree from the well-earned credit due to the talents and skill of this chemist, so respect- ably known to the screntific public, when I venture to state that I am inclined to believe he has rather over-rated the power of coke, in stating it as three to onef , unless his coke be considerably better than mine obtained from Welsh culm. My experiments in the rough way gave about two to one, comparing it with coal weight for weight. I have also no doubt that coke might be advantageously employed in the smelting- houses. 14 pounds of brass can be fused in a portable chemical furnace, by means of coke, in 48 mi? nutes, which, with compact wood charcoal, I could not ac- complish in less than 1 hour and a quarter. The difference with regard "to price in this case is very remarkable. When the coke made from Welsh culm is once completely ig- nited, (which it readily is, if not de carburet ted too much,) it throws out a very compact and steady heat, and yields but a very slight sulphureous odour ; and this ceases when ft is fully ignited. It lasts a longer time -in a state of ignition than charcoal of wood in a quadruple proportion, and its heat is constantly equal, and of almost the same intensity. It also requires less trouble and attendance.
Having slated above, (and as is indeed well known,) that the brilliancy of the light produced during the combustion of coal s,as is far superior to oil or caudles, and being; de- sirous to know to what this preeminence was owing, I made
* The Report, 5ic., page S4. + Ibid.
£ e 3 a number
436 On the Benefits that may he expected
a number of experiments, of which T shall merely state the results, and not the proceedings. The gas was prepared from Welsh culm enclosed in a common iron pot covered with a head made of brick ware ; the tubes for conducting the gas were leaden pipes furnished with perforated roses like the extremity of the pipe of a common watering-pot. In this manner it was found that the degree of the illuminating power of the coal gas differs according to the degree of heat employed for its evolution. Coal exposed to a dull red heat, just sufficient for the production of the gas, yielded a gaseou3 product, which exhibited much less brilliancy when burnt than gas obtained during a temperature of a bright che-rry redness.
100 cubic inches of the former gas when made to burn slowly from a small aperture under a gardener's" large glass bell, connected with a stone barrel filled with oxygen gas, required 259 cubic inches of oxygen for its complete com- bustion. On removing the residual gas into a stone pan containing a ley obtained from the ashes of brush-wood, 1 14 cubic inches of the gas vanished.
100 cubic inches of coal gas obtained at a cherry red heat, required for its combustion 312 cubic inches of oxygen gas obtained from oxymuriate df potash. The volume of gas, after having been agitated with a like alkaline ley, lost 1 17 cubic inches. Hence the light of this gas, or its inten- sity, is probably in the ratio of the quantity of" oxygen necessary for the combustion of the carburetted hydrogen. An increased temperature produces a gas better adapted for illumination than a gas; procured by a degree of heat merely sufficient for its evolution.
The gas obtained at a low temperature has a much stronger odour than that produced during an increased temperature. It contains a considerable portion of sulphuretted hydrogen ; for on collecting a quantity of it in a gasometer made of two puncheons, the one of which was painted with white lead within,- and suffering the gas to stand in this apparatus, it completely blackened the white paint of the wooden vessel. The gas obtained at an increased temperature acted but feebly on the oxide of lead.
Utft
from the Nature of Coal Gas. 437
On passing a stream of the gas obtained from Welsh culm through a solution of acetiie of lead with excess of acetous acid, it instantly produced a copious black precipitate, which effervesced strongly with nitric acid, and yielded much sul- phuretted hydrogen gas.
A quantity of gas which had been repeatedly agitated in contact with a solution of acetite of silver with excess of acid, when suffered to burn under a gardener's bell-glass filled with common air, deposited a dew on the inner sur- face of the bell ; the moisture produced permanently reddened a blue cabbage leaf, and caused a precipitate in acetate of barytes ; the precipitate was insoluble in dilute nitric acid; the gas therefore still contained either sulphureous or sul- phuric acid ; and hence the gas, when intended for the illu- mination of dwellings, should be procured at a bright red heat. The odour of it becomes under this condition di- minished, and the property of blackening paint is but slight and feeble.
The method recommended to deprive the gas of its odour, by passing it through lime-water, or through lime in a state of ignition, was found to be absolutely insufficient ; continued agitation with lime diffused through water to the consist- ence of cream, with a portion of alkaline ley, was found to deprive the gas of part o£ its strong odour.
If the gas from coal be suffered to stand over water for some days, or if it be agitaled with that fluid, its property of producing a brilliant white light is much impaired. It then burns with a blueish flame instead of a white pnt^ : hence, for the purpose of illumination, the gas should be used as it issues from the distillatory vessel.
Whether the sulphuretted hydrogen gas spoken of is an accidental or unavoidable ingredient in the gas of coal, I have not been able to learn. Indeed the whole nature of the gas seems to be but ill understood by chemists themselves. For, notwithstanding the merit which Mr. Henrv's paper in the Philosophical Transactions for 1808, p. II, describing an apparatus for the analysis of the compound inflammable gas, contains, the results of his experiments cannot be ac- curately relied on. The imperfection of the apparatus em-
£ P 3 ployed
4 38 On the fertilizing Properties of Manures
ployed by this philosopher must -be obvious to every one ; for it cannot separate nor ascertain the nature of aboye one- fifth of the inflammable gas from coal, the composition of .the remaining portion being left still undetermined.
The quantity of gas obtained from one chaldron of Welsh culm, I have reason to state, is sufficient to give a quantity of light equal in intensity to that afforded by 86*9 tallow candles, eight to the pound, burning for 16 hours. The increase of coke in bulk is more than 50 per cent.
The quantity of tar and other condensable products I have not been able to ascertain, owing to the imperfect state of my apparatus. They appear to amount at least to one-tenth of the coal employed, They will probably be found useful hereafter. For cart grease, or to paint palings, &:c, the tar may certainly be used with advantage.
With the pungent ammoniacal saline liquor I have made no rustic experiment.
J.W.Davis.
Tanbymoore, May 1, 1809.
LXXVTI. On. the fertilizing Properties of Manures which contain Ammonia. By Mr, William Cox*.
It is only within the last three weeks or a month that any application was made to me for my opinion on the use of any of the articles produced by Mr. Winsor's apparatus, and therefore I have not had the opportunity of making any experiments with this identical ammoniacal liquor, espe- cially with regard to the use to which I beg leave to state I think it applicable. But it will readily be admitted by several gentlemen present, acquainted with chemistry, that ammonia is a chemical matter, as identical in one situ- ation as in another; and as long as 1 am certain that it is ammonia, it is the same thing if it is produced here or in the North. I was desirous, some years ago, of making am- monia in large quantities, and was of course at some pains
* From Minutes of Evidence taken before the Committee cf the House of .Commons on the Gas-Light and Coke Company's Bill.
which contain Ammonia. 4 $9
in ascertaining what would be the most (Economical process for its production : I had resort to the various different arti- cles of a refuse nature, such as were easily to he procured at the cheapest rate, for the purpose of obtaining ammonia; but I found, however much I varied the article, that, accord- ing to the quantity of ammonia I could produce from that article, the farmers had always been beforehand wiih me in raising the price of it ; as they found it useful in the same proportion in its application on land : and that is as far as I am acquainted with the matter. Of course the production of ammonia, on a great scale, would be of great importance to the agricultural interest.
Are you acquainted with the subject of the use of am- moniacal liquor, in agriculture? — I am.
[The witness here read a paper to the committee,] , Gentlemen,
Your inquiry as to my opinion of the uses to which your ammoniacal liquor is or may be applicable, I shall endea- vour to satisfy as far as the shortness of time will permit. Positive evidence of the immediate result of experiments, which require time and seasons, cannot be obtained in re- gard to such uses as, from the closest analogy and the most reasonable inference, we should be induced to apply this production of your process to. There are many uses in the arts and manufactures to which the application of the am- monia or volatile alkali is well known, and which are al- ready in- part enumerated. But when the demand for these purposes is supplied, and, on the probable great extent of the production of your ammonia, should a surplus quantity remain, I have reason to think, that in some very considerable departments of agriculture that surplus, how- ever great, will find a ready and adequate market. A judi- cious application of ammonia to land before it be sown with turnips, (but if afterwards, on no account after the plants are up,) is likely to produce the most beneficial results. What justifies me in this conclusion, is the simple conside- ration, that all the powerful and concentrated manures of high price, and in great request, are just so in the degree in which I have found them by analysis to contain either am-
E e 4 monia
440 On the fertilizing Properties' of Manures
xnonia or the elements that compose it. Soot, well knowr*. to be in small quantities a powerful encourage* of vegeta- tion, contains much carbonate of ammonia, combined with &)me of the carbonaceous parts, rendering them extractive and soluble in water, forming a brown pungent liquid. Pigeon dung is a dressing for turnip land in great request in the North, where many hundred quarters are annually sold at 121s. the quarter, though a very small proportion of the demand is supplied. I have found, by experiment, that this material is richly impregnated with carbonate of ammonia as well as with the well-known element of ammonia, azote, which, in the natural decomposition of the manure by putre- faction, wheu committed to the earth, will be produced. Rape dust is that particular part of the seed (left after the oil is pressed out) which is intended by nature to corrupt, and become the early cause or stimulus of the growth of the embryo germ, and therefore contains the same element, and which we can readily, by a chemical process, exhibit in the ammonia which rape dust may be made to yield. It is hardly necessary to mention urine, &c, from which ammonia i9 obtained in great quantity, or the dung of all animals, which contains the same principle. It was from the dung of the animals which fed on the fertile plains of Egypt that all the sal-ammoniac known in commerce was for many centuries obtained. From that country, the site of the temple of Ju- piter Ammon, its name is derived. Soon after sal-am- moniac became an article of European manufacture, it was discovered that the bones and horns of animals yielded its peculiar salt, that is to say, the ammoniacal principle, in much greater quantity than their dung, and those parts were aloi>e used to the exclusion of these: hence the name spirit of hartshorn, given to the volatile alkali used in medicine. It has been of late years discovered, that the scrapings, shavings, and chips of the horns used in manufactures (par^ tjcularly of the knife handles at Sheffield) are the most power- ful and the best of all land dressings known ; and it is from these very materials also that the greatest quantity of am- monia is to he obtained, wool, silk, and hair excepted, ancj these are again in great use in agriculture, when collected
and
which contain, Ammonia. 44 1
and sold as old woollen rags. Bones of all kinds, not ex- cepting human bones, are sent by sea in great quantity from this metropolis into the North ; many hundred tons of these are ground, or rather broken small, in mills contrived on purpose, as the quantity necessary for an acre of land is small in comparison of other materials. The convenience of c\tsy carriage is the cause of the most distant lands being brought into the richest cultivation, It would not be pro- per, on this occasion, to enter into a theoretical disquisition on the nourishment of vegetables, whether they derive their food wholly, or only in small "part, from the earth by their roots, or from the atmosphere by their leaves and green parts j but it appears clear to me, that that principle which the farmers term warmth and force, is constantly accompanied by the chemic element mentioned. This stimulus of en- couragement and force is of more consequence to the growth and eventual vigour of annuals than of perennials, and par- ticularly at the early periods immediately succeeding the ex- penditure of this sure principle which nature has provided in the seed. The putrefactive fermentation always gene- rates ammonia; the earth imbibes the different miasmata, and holds them in store for the use of plants ; to these they impart health, strength, and, as may be said, ap- petite.
A great difference is observed by farmers in the qualities of the manure of cattle, when fed on oil cake^r on hay; it is supposed to be of four times the value in the first case. The beneficial effects of sometimes mixing lime with arable soil is easily explained in this way. The ammonia is always to be recognised by its peculiar smell. As soon as newly slacked lime is mixed up with the mould of a good soil, but which is beginning to show signs of impoverishment, In this case, the ammonia, which had formed a chemic combina- tion with the fixed acids of the manure (formerly ploughed in and fermented) is set at liberty. These are the phospho- ric and vitriolic acids, which, as i.s well known, will leave ammonia to combine with lime. I have therefore no hesi- tation in declaring, as matter of opinion, that the production
of
442 A Reply to Mr. Carr's Letter,
of ammonia, in great quantity, and its judicious application to agricultural purposes, are processes of' very great impor- tance to the landed interest.
LXXVITI. Geological Observations on the Excavation of Valleys, and local Denudations of the Strata of the Earth in particular Districts, &c, in Reply to Mr. John Carr's Letter in the last Number, p. 385. By Mr. John Farey.
" It is only from the itinerant geologist cautiously pacing over various and extensive districts, and marking with experienced intelligence the wonderful phenomena which every where present themselves, that we can hope to ob- tain that accumulation of practical facts which can alone guide us to a sober and correct theory of the natural causes which, at remote periods, have ope- rated those stupendous changes which are every where seen on and near the surface of our globe*." John Carp..
To Mr. Tilloch, — Sir, A. wet morning, which seems to threaten an interruption of some hours' duration, to my researches in the highly in- teresting district which surrounds this town (Sheffield in Yorkshire), presenting the opportunity of looking into the last Number of the Philosophical Magazine, I have been induced to trouble you with a few lines, in explanation of some points, which your able correspondent Mr. John Carr of Manchester has touched upon in his Letter therein. In the present state of geological knowledge, nothing can be more just than the introductory remark of Mr. Carr, which I have quoted above, as to the class of persons who are at this juncture most likely to trace out and discover the natu- ral causes which have operated, in effecting the present state and condition of the earth ; arising from the circumstance, that very few, of the great and leading/ac/s appertaining to the crust of the earth have yet been touched upon, much less have they been so fully treated on or illustrated by geo- logical writers, that " the closet geologist" can, over an ** accumulation of practical facts," sit down, and deduce ff a sober and correct theory," or even judge of the truth or • Vide p. S35.
otherwise^
ly Mr. John Farey. 443
otherwise, of suggestions as to causes, which " itinerant geologists ?■ may advance. This state of things ought not, however, longer to continue, but the exertions of every well-wisher to science ought to be redoubled, in tracing ou^ and fully describing the facts which the British strata present ;. were it only for securing to this country the honour of per- fecting, and rendering the important discoveries of Mr. William Smith relative to the strata and their alluvial ruins, as subservient to science as they have already begun to be to the mining and other ceconomical interests of our coun- trymen, in different counties.
Wonderful and important as the discoveries made about ] 7 years ago have proved, as to the certain order and con- tinuous planes- of the undisturbed strata, each of which, al- most, entombing its own peculiar remains of organized heings; and the more recent results, that all such are per- fectly distinguishable from the present race of animals and plants occupying the surface of ihe strata, as well those parts of them which are now sub- aqueous, as the others: yet, without the means of accurately distinguishing alluvial or • moved matters, from the stratified sand and other substances, which have hitherto been almost universally confounded with them ; of discriminating between the extraneous and the local alluvia of any district ; and further acquiring the knowledge, that faults or fissures, slips, throws, or what- ever else they may be denominated, are the mere fracture and displacement of the piles of strata, and do not in any instance affect the order or nature of the strata, (beyond their immediate vicinity,) when an extent of the series is taken into account, commensurate with the derangement that the two parts of the separated pile of strata have sustained, and the effect of a subsequent denudation or excavation of the surface to its present diversified form of hills and valleys is duly considered : without, I say, that- these latter facts and their practical applications were also known and made, the order and continuity of the strata might still have remained as unproductive to geological science, or even to scientific mining, as they havehitherto proved in the hand* of practical collier* and ironstone miners, who have been fully aware of
these
444 A Reply to Mr, Carr's Letter,
these two points, nay all their operations have been founded upon them, from the earliest periods in the practice of their arts : but unfortunately, with some rare exceptions, such have confined their researches to their own particular fields or to very limited districts round them, and have loo often satisfied themselves, with the most vague and unsatisfactory guesses, at the identity of the particular strata worked By the miners in other districts, even of those which adjoin, in nu- merous instances : and I am sorry to add, that after visiting more than .200 collieries between Nottingham and this place, and conversing with the owners or workmen or both, upon jnost of them, I have not been able yet to discover any two whose ideas are perfectly consistent with each other, as to the identity or otherwise, of the coal and ironstone working in places distant from their own works : my confidence, however, increases daily, of being able (should health and prudential considerations admit of a sufficient application of time to the subject) to reconcile all the facts 1 have col- lected, to the satisfaction of this great body of practical men, and to scientific inquirers in general. The zeal which X feel, for stimulating others, better qualified than myself, to enter on and pursue similar and even more minute inquiries in this or other districts, than I have been able to accomplish or attempt, has however here led me beyond what I in- tended at present: and I return to page 385 of your last Number, in order to notice the opinion advanced by Mr. Carr, that ie solely from the superior durability of its ma- terials, which have withstood the operation of those tre- mendous agents that have swept away the surrounding country/' are we to look for the cause of an isolated moun- tain composed of successive piles of strata i in order, on a point of so much moment to mention, that though a grit- stone rock very often occupies the very summits of hills in the coal districts, yet that such are generally , too soft and their blocks adhere too slightly, to admit of our referring the form of the \\\\\ solely to the resistance these rocks offered either to a violent action of gravity from above, (as I have supposed,) or to the sudden or even to the long-continued action of " water/' moving oyer the surface according to
ly Mr. John Farey. 445
any law which I have been able to imagine : besides, to what part of the earth's surface is the abraded matter removed ? The very extensive denudaled district which I am now in, furnishes a quantity of local alluvia inconsiderable indeed; all that I have yet seen, would not, if added together, amount to the thousandth part of the quantity removed from a single mile in length, of each of a hundred different ex- cavated valleys, which I could refer to on my map, and the little that there i?, is almost invariably found so near to thq present currents of the rivers and brooks, as to be naturally enough referred to the torrents which hurry through these valleys in ordinary heavy rains; not to mention the bursting of water-spouts 8tc. which we are at liberty also to suppose may have occurred, on the hills above. The hummocks of gravel in Derbyshire which I have mentioned page 261, as well as the immense tract of sandy gravel on Sherwood Forest in Nottinghamshire, belong to the extraneous al- luvia, and contain no pebble or stone, wherein a high de- v gree of rounding, does not concur, with its chemical qualities, in proving the distance it has travelled, to its present rest- ing-place. . I cannot but entirely dissent from the opinion adopted by Mr. Carr, at the top of the next page, viz., that the terrestrial strata " could only le derived from the de- structive transportation of other strata, equally extensive; and the present elevation of stratified mountains is demon- strative evidence of the countries which, in disappearing, have furnished such vast masses of diversified materials for the formation of other stratified countries in other situa- tions/' because, such ideas have been often promulgated, and found so " utterly incongruous" with the phenomena which the strata themselves present, both in the regularity of their planes, and the lodgment of* perfect and peculiar organized remains in them, respectively, that I cannot but consider it, " at once matter of surprise and regret," that Mr. Carr should have compared this exploded notion, with the principle of gravitation, as elucidated by Newton, Ti Simpson, and La Place, to the entire accounting for, all phenomena, to which it has been legitimately applied.
From
446 A Reply to Mr. Carr's Letter,
From what source can it be inferred, that the "present laws of Nature," as Mr. Q, has defined them, have been in ac- tion millions of years ? any more, than that the fanciful creation of an tk erratic planet*' is intended " for accomplish- ing, almost in an instant, that which, far more probably, re- quired many thousands of years to effect?" My personal acquaintances well know, that I have all along supposed the probable period to be very long ; during which a satellite revolved in a continually decreasing orbit (from causes that are perhaps assignable, without clumsily cutting any Gordian knot) and effected the stupendous operations on the strata, previous to its fall into, and assimilation with, the com- pound mass of the terraqueous globe, which it is the busi- ness of " closet" as well as " itinerant" geologists to in- vestigate and understand fully, before they pronounce the proposer of a new application of the principle of gravitation to the earth, as a person forsaken by the genuine spirit of philosophy, and become u bewildered in the unprofitable maze of hypothesis I" Surely gravity (as exemplified daily by the tides, p. 250,) may safely be classed among the " present energies" of Nature : and who is there, that can- not perceive, that the energies, be they what they may, which effected the disruption and denudation of the strata, must have acted in degrees and modes, utterly distinct from those which have prevailed, since the last and great opera- tions of creative power were performed, in the creation of the present race of vegetables and animals, and of man, whose reasoning faculties rendered him capable of tracing back to events, which took place long, very long prior to the existence of his species.
Strong as the language 1 have used herein may at first seem, I will not anticipate the slightest irritation in Mr. Carr thereat, much less art explosion of any thing like viru- lence on his part, but on the contrary, cordially wish, that he would engage seriously in applying the action of water, (without the reversed and deranged action of gravity) to the explanation of the phenomena presented by the neighbour- hood of Manchester, or any other which he may choose,
an<i
hy Mr. John Farey. 44?
and convey to us, both the facts and the reasonings, through the medium of your useful Magazine : recollecting, that the tides which I have supposed, necessarily imply all the me- chanical agency of water, which is consistent with the pe- riodic time and circumstances of the satellite occasioning them and giving impulse to the fluid ; and Mr. Carr will not, I hope, fail to consider, and inform us, of the motive forces propelling and directing his (( incessant operator" in the excavation of valleys. The example of the immortal Newton, in declining to attempt the definition of the cause of gravity, to which neither he nor any one else have yet found themselves equal, shall be my excuse, in not at- tempting a conjecture on the manner in which the forces were directed, which excavated the valleys; the facts of many of them having been mechanically excavated, and that none (comparatively speaking) of the displaced mate- rials are now any where to be found, are, as I think, incon- trovertible.
Perhaps Mr. Carr, when he speaks of water having given w mobility and transportation to such massive and diversified materials, " as compose the strata, had not contemplated a supposition, which forced itself upon my mind, after having perceived the difficulties which his position involves, viz., that each successive stratum in ascending the series, was created since the animal or vegetable remains which it co- vers, had completed their growth, and the deposition of which stratum, or its precipitation from the superincumbent fluid, perhaps, occasioned the successive extinction of these organized beings. The universal prevalence of grains in siliceous strata, suggests the supposition, as I think, that something analogous to the formation of kail in a storm, (in irregular crystals) took place during the precipitation of silex, generally, in very minute grains ; but in the first or Mill-stone Grit Rock (vol. xxxi. Plate II.) it is not uncom- mon to meet with grains half an inch, and even in some cases three quarters of an inch in diameter, having that smoothness of surface, as to induce Mr. Whitehurst and many others to describe these large siliceous grains as rolled pebbles, but which opinion 1 never could see reason for adopting; the
surface
443 Contrivance for preventing Doors
surface of these large grains, appearing^to me, no way dif- ferent from the surface of the smallest siliceous grains, when viewed by a m3gnifier proper for showing each under the same apparent angle. I am, sir, your obedient servant,
Commercial Inn. Sherfk-ki, JOHN FaRKY.
June 6, I809j
LXXIX. Contrivance for preventing Doors from Dragging on Carpets. Bij Mr. John Tad*, sir,
X have taken the liberty of laying before the Society a model of my invention to prevent doors from dragging on carpets, and to keep out the current oF cold air, which en- ters under such doors as are not close to the carpets under* neath them.
I can affix this machinery to the bottom of any door, so that the door shall pass over the carpet with ease, and, when shut, be air tight. Jt obviates the necessity of screw rising hinges, and is less expensive than other inventions for the same purpose.
'The machinery is constructed of a slip of well seasoned beech wood, equal in length to the width of the door; this slip is one and a quarter inch wide, and half an inch thick, and to be covered with gTeen cloth on the inside ; it is to be hung to the bottom of thevdoor with three small brass hinoes, and is drawn up by a concealed spring as the door opens, and is forced down when the door shuts, by one end of it, which is semicircular, pressing upon a concave semi- circular piece of hard beech wood, fastened at the bottom of the door case, and which holds it down close to the floor or carpet, so as to exclude the air from entering under it. Hoping this invention will meet with the approbation of the. Society, I remain, with respect,
Sir, your most humble servant,
No. 4, Little Hermitage Street, Wapping, JOHN TAD.
Nov. 24, 1807.
To C. Taylor, M.D. Sec.
* From Transactions of the Society for the Encouragement of Arts y Manufac- tures, and Commerce, for 1808. Five guineas were voted to Mr. Tad for
his communication*
Reference
from Dragging on Carpets. 41 9
Reference to Mr. Tad's Method of preventing Doors from Dragging on Carpets. See fl. XIII. Figs. 1, 2, 3, and 4.
Mr. Tad's invention consists in first cutting away the bot- tom of the door, so that it is about one inch and a quarter above the floor; this allows a sufficiency of room for the door to open over any carpet. To close the opening which would now be left under the door when shut, he proposes to fix beneath the door, by means of hinges, a slip of wood, of which a bde, figs. 2 and 3, Plate XIII. is a section. Fig. I is a perspective view of the bottom of a door, with the invention annexed to it ; fig. 2 is a section across the door when closed ; fig. 3 is a view of the edge of the door when open ; and fig. 4 is a section supposed to be made by cutting the door in two parts, edgeways. The hinges, oh which the slip turns, are fixed to the edge. In figs. 2 and 3, from a Xob, is exactly one inch and a quarter, so that when the ruler is turned down upon the hinges, it reaches the floor A A as in fig. 2 ; in the other direction a d it is much less, being only half an inch, so that when it is turned up under the door, as in fig. 3, it leaves three quarters of an inch clear of the floor. It now remains to show how the ruler is turned up or down : — it has always a tendency to rise up into the state of fig. 3, by the action of a steel wire spring, shown in figs. 2 and 4, which is concealed in a rebate cut in the bottom of the door; one end of the wire is screwed fast to • the doof at f) the other is inserted into an eye fastened into the slip at g, to throw it down into the position of figs. 2 3nd 4. The end k, fig. 4, of the slip furthest from the hinges of the door, is cut into a semicircle, as seen in 6g. 3. When the door is just closed, this semicircle is received into a fixed concave semicircle k9 fig. 3, cut in the end of a piece of wood k Z, made fast to the door-case ; the line m /, fig. 3, represents the plane of the door when shut, and p p part of the door seen edgeways : as the door in shutting moves from p to m, the semicircular end of the slip aide presses against the end of the piece k ly and as the door pro- ceeds, it turns down as in fig. 2, so that by the time the door is shut, the slip is turned quite down; the edge e b of the
Voi. 33. No. 134. Jane 1805. * F f aHp
456 Description of an Improved Screw Wrench
slip is cut into a segment of a circle struck from the binge* on which it turns. The perspective view in fig. 1 shows that this contrivance, applied to any door, will not offend the eye, as it can scarcely be d.stinguished from an ordinary door. A", fig. J, shows the concave semicircle of the piece of wood fastened to the door-case, in which the semicircular- end of the slip e is to be received.
**=SF
7
LXXX. Description of an Improved Screw Wrench to fit different -shed Nuts or H^ads of Screws. By Mr. Wm. Barlow, of His Majesty s Dock Yard, Portsmouth*.
p S,R'
XTermit me to make a few observations on a shifting screw? wrench of my invention, wfjich I beg leave to lay before the. Society of Arts, &c, through the hands of Mr. Brunei, inventor of the block machinery here.
I have found, from long experience, the imperfections of the various wrenches in common use, for the screw heads and nuts of engines in general, which are often materially^ injured for want of an instrument which would fit variety of sizes, and be applied with as much advantage as a solid. wrench. I have had it in view to unite steadiness with con-; veniency in making such an instrument; and flattering my- self that I have obtained both, I am desirous to communi- cate my invention to the Society, and have therefore sent, an instrument on the principle I have actually used, and; w.hich.has met with the approbation of my employers and, other persons.
This wrench, by means of a nut and screw, is adjusted with the greatest ease to the exact size required, and in that, state rendered so steady that in use it is found equal to a. 3olid wrench. r.J,l^
• I have> for several years, been intrusted with the care and. repairs of many valuable engines of various descriptions,.
* "From Transactions of the Society for the Encouragement of Arts, Mami- fdcture^, and Commerce, for 1808.— i — Five guineas were voted to Mr. Barlow for this commuflkatioa. . •" '•
ll ,* . . • . ^ * : 'composing
to Jit different -sized Nuts or Heads of Screws. 451
composing the block machinery in this dock-yard* and I have always considered it as an object of great importance, for the preservation and neat appearance of engines, to at- tend to all the means which would obtain these advantages, and such, 1 think, will arise from the use of my universal wrench.
It is, perhaps, unnecessary to point out, that a wrench on this principle mav be varied in its form and size, so as to be rendered probably more convenient for some particular purposes for which such instruments are required.
I am, sir, your obedient servant,
Portsmouth Dock Yard, Wm. BARLOW.
March 1, 1808.
To C. Taylor, M.D. Sec.
Reference to the Engraving of Mr, Barlow's Improved Wrench. See Plate XIII. Figs. 5, 6, and 7.
This instrument is represented in Plate XIII. Fig. 5 is a perspective view of it ; fig. 6 a section of its head ; and fig. 7 an external representation of the head. The screw head or nut to be turned is held between twt> jaws, one of which a b d e is forged in the same piece with the handle A A, the other, f g, is moveab'e between two chukes, and fastened to the fixed jaw by the strong screw i, which is fixed to the same jaw, passes through the moveable one, as shown in the section fig. 6, and has a nut screwed upon it ; the other screw, h, is tapped through the moveable jaw, and its point presses upon the bottom of a cavity made in the fixed jaw shown at m in the section fig. 6. To make the wrench fit any particular screw head or nut, the nut upon the strong screw i must first be loosened, and the screw h screwed in or out of the moveable jaw, until the opening hg is just the proper width to receive the screw head or nut to be turned by the wrench j the nut of the screw i is then to be screwed down, until it presses upon the jaw, and holds it perfectly tight.
Ffs LXXXI. On
c m 3
LXXXl. On the Natural Causes which operate in the Forma- tion of Valleys. By John Carr, Esq,
**■ Revolving the circumstances of excavated valleys in my mind, as I have observed them wonderfully distributed over the whole surface of large di- stricts, effecting a descending outlet or drainage to any part : I have been lost in conjecturing any application of mechanical or known principles, that could have directed the almost irresistible forces, which effected this impor- tant, and as k were finishing operation on the matter of our globe, but refer the same to Omnipotent Power itself, acting, perhaps, in this instance, with- out the intervention of the agents whose operations in Nature the light of science enables us in so many instances to trace."
Mr. John Farey, Philosophical Magazine for April 1809.
To Mr. Tilloch, — Sir,
jL he above M most lame and impotent conclusion" fur- nishes a very singular instance of the great difference between observing and judging ; between the accurate perception of effects, and the more rare and discriminating faculty of drawing from their common agreement and general com- bination, just and rational deductions of their cause. Phe- nomena so extensive, combined in such union, and ope- rating so indispensable an office in the wise ceconomy of Nature, surely ought to have suggested a more natural and philosophical inference. To me, there are few things more evident than that " the irresistible forces" which have effect- ed the excavation of valleys, are no other than the identical" streams which now flow through them ; and that by means go natural and obvious, as to excite extreme wonder how so experienced and intelligent an observer, as Mr. Farey un- questionably is, can have surveyed the practical facts, and reflected on the subject, without arriving at the clearest conviction.
Every river which disembogues itself into the ocean is the great drainage trunk of a considerable extent of country, receiving through every part of its course lateral streams, which again receive others, and these others still, in so much that the river itself is frequently the receptacle of hundreds of other streams of various magnitude and extent ; and not only the river, but every brook, however remotely con- nected, has its peculiar range of valleys, which afford it the
2 most
< 1 *
On the Formation of Valleys. 453
most easy and direct communication with the stream into which it falls: and all these ranges of valleys are as sub- servient to, and as intimately connected with,. the exten- sive and general system of drainage of the country, as the streams themselves ; and the uniform direction, general con- nection, and admirable subserviency of the whole, are so palpable, that we are irresistibly led to one of two conclu- sions,—either that the several ranges of valleys have been purposely and specially formed for the streams which now flow through them, or that the streams themselves have scooped out their own peculiar valleys. The former opinion is too absurd to merit a moment's attention ; and the latter has so many direct and positive proofs in its favour, as to yield the most satisfactory conviction to any impartial and competent mind, that will take an actual survey of the spring heads and courses of even the most trivial brooks.
But though there are no natural operations whatever, that from personal inspection more clearly illustrate themselves than this operation of streams in forming their own valleys, it is a subject of considerable difficulty when limited to mere description. The proof circumstances, in all their com- binations, are distinct objects of visual inspection, and when spread out beneath the eye exhibit a connected chain of il- lustrative evidence irresistibly convincing; but the same im- pressive picture is comparatively faint, and its beautiful unity broken into fragments, like the landscape i-n the rippling stream, when held up to the " mind's eye" in the closet. Nevertheless there is a bold prominency in the outline of this natural scenery, which even the pen can trace, and I will endeavour to delineate it in a brief and hasty sketch.
The horizontal parallelism of the upper brows of vallevs, and of the strata and their identity in the opposite banks, have long ago demonstrated that the strata were formerly continued across, and that the valleys have been formed by the strata being cut through and the missing portions carried away. The truth of this no one will question, who, by ac- tual inspection, has given due attention to the facts upon which it rests.
The source of every stream is always situated on a higher ¥ t* 3 level
454 On the Natural Causes which operate
Jevel than that of the country through which the valleys have been cut ; and were they all filled up, there would still be a sufficient fall in the country for the streams to flow the same wav : and as water, when left to itself, by its fluidity and gravitation constantly seeks the lowest place, we may always be assured that the conrse which the stream has taken is the lowest descent of the country in that direction. With these circumstances in view, let us select any indi- vidual stream, and suppose all its valleys to be filled up by replacing the very materials of the strata formerly carried off, thereby restoring the country to its pristine state before the valleys were excavated; and then, by attending to the course of the stream from its source, we shall acquire a clear and porrect conception of the manner in which the valleys were oripmally formed. The old channel being in the lowest fall of ti.e country, the stream will still flow in the same direc- tion, but it wijl be on and over the newly restored mate- rials, which we have supposed to be replaced ; and it will first pass over that portion which has filled up the first val- ley, until it arrives at what was the lower end, which being now a declivity, it will be precipitated into the hollow below. In that hollow or flat the water will spread itself out into a lake, wider or narrower in its dimensions ac* cording to the form and bearing of the ground; and the lake continuing to fill, the water will rise over the level of the materials which filled up the second valley, and running on to where was the lower end, it will again descend the declivity into the hollow below, and will accumulate and spread itself until it again rises over the third valley, and descend again at the lower end; and in this manner it will continue its course, falling down every declivity which it reaches, and accumulating into a lake wherever the nature of the ground obstructs it, until the water reaches over the level oi the obstructing rise ; and the stream in this stage of its course will consist of a chain or streams, waterfalls and lakes, from its source to the channel of the next stream, or
ot these., its if, the grandreceptacle of the whole. Let us
nov\ attend to what will take place at the several falls. There, in -every instance where the stratum is not an indurated rock,
the
in the Formation of Valleys. 455
the momentum and action of the descending water .will cut a channel, deep and expeditious in proportion to the height of the fall and the yielding nature of the stratum: and as this channel deepens, the unsupported sides will fall in, and the materials be swept away into the lake below. The water will continue this process, but with diminished force, as the inclined plane becomes less steep, until it has again exca- vated a valley similar to that which we have supposed to be filled up : and this new valley, opening directly intothe lake above, the lake will, in time, be completely drained off, and the stream will soon work itself out a limited chan.- nel in the alluviai materials which have formed the bottom of the lake, and which had been brought down from the detritus of the valley above. After a certain time the whole course of the stream will be changed, in this way,- from a succession of streams, waterfalls and lakes, into a succession, of valleys and alluvial flats,- such as we actually now fin^ existing in the course of almost every stream * If the fla* ground a little way beyond any valley be examined, below *he vegetable mould, it will- be found to consist of sand, gravel, and other alluvial materials precisely similar to the strata in the valley above ; and if the valley immediately be- low be filled up, a lake will forthwith be formed above it, &nd covering the.alluvial materials which had formed the bottom of the former lake: — and these two important facts, capable of the most direct proof in every district where val- leys abound, are surely decisive evidence that the original course of the stream did consist of a chain of vaterfalls and lakes, and that the falls have worn out the valleys backwards, into the lakes above, thereby giving vent to their waters, and leaving the course of the streams, as we now find them, a succession of valleys and alluvial flats.
It may be easily imagined that the valley will be deep and capacious in proportion to the height of the waterfall where the excavation commences, and that the exit of the water in the lake above will increase the fall in the next valley up- wards; and it may also be readily conceived, that when the action of the water has worn the inclined plane, down wlWn it descends, to a certain point, all further excavation of the
F f 4 channel
i$6 On the Natural Causes which operaie
channel will cease, and that the stream may continue to flow •for innumerable ages with but trivial alterations in its course. This is the true reason why *we do not now see streams forming valleys, the work having been long since accom- plished by the channels being reduced to their lowest de- scending level : and only by the bursting out or' a^ new spring head, in a situation distant from any other stream, could we now practically observe the progression of falls and lakes into valleys and flats, in the manner described. The progress of the stream flowing from such a new spring head would most assuredly establish the truth of every thing I have already stated. For it cannot be doubted that every stream must originally have formed its own channel ; and it must be equally obvious, that when first left to find its ov n way over a great inequality of sur- face, it must frequently have precipitated down declivities into hollows, out of which it could have no other exit than by swelling into a lake, until the water rose over the level of the lowest ground which bounded the hollow,
In many cases a valley commences immediately at the source of a stream, just opening there and gradually deepen-? ing downwards to the lower end, where, questionless, the Stream once fell, and where the cutting of the valley com- menced; and this form, of being shallow at the upper and deepening down to the lower end, where the fall of the Stream first began to act for its formation, is also common to numerous valleys, more especially those near the spring heads ; and while it perfectly accords with the action of the stream, it is utterly irreconcileable with any other explana- tion. Nothing, too, is more usual than the intersection of one valley with another at the confluence of two streams; and in every such instance the angle of intersection of the valleys and streams is acute above and obtuse below, and the two streams invariably meet on precisely the same level. All this would naturally and necessarily result from the streams forming their own valleys and channels, but it is utterly impracticable to assign the most remote probable cause for the same union, and unison of effects by any other na- tural means.
in the Formation of Falleys. 457
In some cases, indeed, the capacious magnitude of the valley, compared with the diminutive size of the stream, might arrest our belief of so trivial an agent having accom- plished so great a work ; but those occasional and powerful floods to which every brook is subject, the immense dura- tion of the- action, and the yielding nature of the earthy materials removed, are amply sufficient to suppress- every doubt and to reconcile every difficulty.
There are multitudes of other practical facts which the actual survey of the course of streams readily supplies, and all of them speaking the same forcible language, of the streams themselves being the only agents that have broken down the opposing obstacles in their course and reduced their channels to the regular gradation slopes down which we now find them flowing.
Those who may be desirous of verifying these observations on the formation of valleys, have only to visit the spring- heads of their neighbouring streams, tracing the channel downwards, and they will find little difficulty in marking the site of every former lake and waterfall, by only sup- posing the valley which lies before them to be tilled up; and the obvious effect will be a lake at the upper and a waterfall at the lower end : and a proper examination of the soil below every valley will discover the very materials formerly brought down when the valley was excavating.
The very intimate connection between waterfalls and lakes, and their disappearance together, by the former effecting breaches into the latter, has been very fully dwelt upon ; and accordingly where waterfalls now abound, there ought to be a corresponding abundance of lakes ; and this is strikingly corroborated by the fact. Canada is productive of the most numerous and celebrated waterfalls, and there also, ahove these falls, are the most numerous and most extensive Jakes on our globe.
Every waterfall that now exists is produced by a stratum of rock crossing the course of the stream, and it is solely owing to the indurated durability of the rock, that we now find a fall where we should otherwise have found a valley. Tins is so evident, that many of our most celebrated water- falls
458 On the Formation of Valleys.
falls arc not precipitated from aii open height of higher ground, but down into a deep chasm, or rocky valley, formed, undeniably, by the violent action of the water, which has continued, and is still continuing, from the de- tritus of the rock, to remove the fall higher up the stream : such strictly is the case with the far-famed Palls of Niagara. The surrounding country is nearly on the same level, and the river is propelled over an immense bed of rock, down into a profound valJcy, which extends for nine miles below the falls, and with every appearance of having been formed by the progressive removal of the fall backwards, in conse- quence of the gradual waste of the rockby the destructive action of the water.
But there is another point of view in which this magnifi- cent waterfall ought to be considered as eminently illustra* live of the subject under consideration. The height of the fall, and what are called the rapids immediately above it, is upwards of two hundred feet ; and there is a still further considerable fall -in the descent of the river from the lake above. • - ■ *
• Now it certainly requires but a small effort of mind to perceive that the vast stratum of imperishable rock which crosses the channel of the river^ has alone prevented the St. Lawrence from excavating one of the largest and most capacious valleys on our -globe, and that the excavation would have extended upwards into lake Ontario, liberating its waters,- and leaving the river to form, for itself, a chan*- jief through the central antl.deepest parts of the exhausted hke.
•. The retreat of these waters would be productive of another vast fall in the channel from lake Erie, and that fall again excavating a valley upwards, and into the lake, would oc- casion the exit of its waters, which again, would produce a fall and excavation up into lake Huron, the retreat of whose waters would be followed .by falls from, and excavations irito, lakes Superior and Michigan; and hence this exten- sive chain of immense lakes would disappear, leaving iu its im equally extensive chain of valleys and alluvial flats, similar, -but on a far more gigantic scale, to the thousands
of
Introduction to the Study of Mineralogy. 459
of Jakes which have disappeared by the same natural process in every country.
I fear, Mr. Editor, I have trespassed much too far on the limits of your truly estimable record of scientific papers; yet I trust the subject is one of superior interest, by bringing us acquainted with the origin of those beautiful excavations which adorn so much of our landscape, and add so much of pleasurable variety to every excursion. They offer how- ever, still higher claims to our attention from their para- mount usefulness in the provident (economy of Nature, by operating, with such admirable and subservient address, and such a harmonized system of combination, as the universal conduits of all the waters of every country.
I am, sir, your most obedient humble servant,
John Carr,
princes Street, Manchester, June 10, 1809.
kXXXII. Introduction to the Study of Mineralogy. By M. Hauy.
[Concluded from p. 401.]
XSut the authors of systems of mineralogy, without even excepting chemists, have followed a very different course, They have considered each metal as the base of a particular genus ; and in the case in which this metal existed per sef in the state of native metal, it would form the first species of the genus ; and its combinations with different principles would give the other species. Thus, in the genus of copper, we should have successively, as species, native copper, oxide of copper, sulphuret of copper, carbonate of copper, itiut riate of copper, ike. In short, metallic substances have characters so striking, that they have been adopted with one accord, as the fixed points around which all the combina* tions ought to rally of Which they form part.
Now, uniformity of method would require, that the same rule which had been followed in the arrangement of metallic substances should also preside over that of substances pro- duced by the union of an earth with an acid 5 z. e. lime, for
example,
460 Introduction to the Study of Mineralogy .
example, should be considered as the basis of a genus, which ihould have as its species the combinations of that earth with the carbonic, phosphoric, and fluoric acids. It is evi- dent that all the parts of a clear and distinct distribution should he symmetrical, and that one method cannot be adapted to two different scales; otherwise it would no longer be a method.
But if the natural order should prescribe to us to deter- mine the genera according to the most rixed principle of each compound, nothing should hinder us from generalizing under another view the employment of the acids, by bor- rowing from these principles a classical character, serving to connect with each other all the substances not me- tallic of which they form part; and henceforward those 6ubstances which bear the name of salts would be united in one and the same superior division with others ; such as the carbonate of lime, phosphate of lime, sulphate of ba- rytes, &c, which had been ranked among the stones. This intimacy had been already as it were prepared for by the transition of the calcareous sulphate from the class of stones into that of the salts. The characters drawn from the solu- bility in water and from the taste, so little remarkable in these substances, had almost obliterated the boundary between the two classes; the definition of salts had become vague and equivocal ; and it appeared to me that it would be to restore order and precision into the class of bodies which had borne this name, to introduce into it all those which contained an acid joined to an earth or an alkali, and some- times to both. The collection of all these bodies will there- fore form the first class, or that of acidiferous substances*. I shall exclude the metallic salts, in order to arrange them among the metals, always taking care not to fritter down the genera. This class will be subdivided into three orders, the first of which will comprehend the earthy-acidiferous substances, the second the alkaline-acidiferous substances, and the third the alkalino-earthy-acidiferous substances.
* The author uses this word uniformly to express those substances into which acids enter as one of their component parts. We shall -therefore re» tain the term in our translation. — Edit.
The
Introduction to the Study of Mineralogy. AG\
. The second class will be formed of the substance?; which I call eartky, i. c. of those which admit no acid among the earths that enter into their composition. I do not think that we are as yet sufficiently acquainted by analysis with the number and proportions of these earths in a part of the substances in question, to be able to subdivide this class into genera. Thus, I shall content myself with presenting the series of the species it contains, taking advantage only (in order to arrange the terms of this series) of analogies or differences which the knowledge we already possess admits of our perceiving among them.
Let us hope that the chemistry of minerals, which since the days of Cronstadt and Bergman has made so great pro- gress, will at length attain a point of perfection which will place this class, and even certain parts of subsequently de- scribed classes, upon a level with the first. We have seen for several years discoveries succeed each other rapidly. Klaproth has furnished us with zircon, uranium, titanium, and tellurium. To Vauquelin we are indebted for glucina and chrome. — Analyses made by one person have been ve- rified by others. What may not science gain by this for- tunate concurrence ?
But if the second class still leaves any thing to desire re- lative to the regularity of the whole, I flatter myself that I have at least contributed to perfect it in its details, not only by a more exact division of the substances which constitute the species, but also by the care which I have taken to apply this name only to those substances which really de- serve it, and to those which have a type susceptible of a pre- cise determination*. Thereby we exclude from the method, and throw into a separate appendix, the argils, marls, and every other similar aggregate composed of fragments bor- rowed from different species, and consequently possessing mixed characters.
I comprehend under a third class the common name of
* Thus the beryl and emerald are ranged in one and the same species . the zeolite, on the contrary, is divided into four different species : the strahi- stein of the German mineralogists, into two forms very distinct from each •ther.
coml ust ill*
46*2 Introduction to the Study of Mineralogy.
combustible substances ; the different non-metallic bodies *u*ceptil>]e of combustion, such as the diamond, sulphury and minerals known by the name of bitumens. Among those substances some have hitherto resisted the attempts made t<> analyse them ; others, treated by distillation or by other means, give out several of the principles which en- tered into their composition. This difference naturally in- dicates the subdivision of the class in question into two orders, distinguished from each other by the denominations of simple and compound combustible substances.
The metalic substances still remain, which give the fourth class, subdivided into as many genera as there are metals. Under each of these genera is to be ranked as a species the native metal when it exists ; then the metal com- bined, either with another metal, with oxygen, combustibles, or acids. With respect to the orders which subdivide this class, I have formed them after the example of Bergman, who has borrowed their characters from circumstances which determine their oxidation and reduction, by placing in the first order those which are not oxidizable, but only reducible by heat : in the second, those which are oxidized when heated, and which, when heated more strongly, are reduced : and in the third, those which are oxidizable, but not redu- cible by heat *.
* The relations which characterize the divisions and subdivisions of the chemical methods being founded upon the intimate properties and upon the composition of bodies, these methods will at first appear to give way to a certain point to those who employ external characters, and in some measure more accessible characters, in order to establish the classification. I have at- tempted to supply the place of it, at least relatively to the great divisions, by characters easily ascertained. To conclude : I have not thought that the consideration I have mentioned can balance the advantage of presenting a distribution founded upon the very essence of the substance which it em- braces, and at once more symmetrica!, more satisfactory to the mind, by. givin"- legitimate order to our ideas. What furnishes an additional motive for supporting this preference is, that, the number of mineralogical species being very inconsiderable, the instant they are once clearly circumscribed, the principal object is fulfilled. For in this case we gain by a little practice such a stock of knowledge, that, when a mineral presents itself for the first time, nothing remains in order to determine it than to decide between two or three species, successively trying the characters which distinguish, each of them, until wt have removed all doubt.
The
Introduction to the Study of Miner alngtf, 403
The choice of a method founded upon the results of ana- lysis naturally led me to adopt, wherever I could, the new chemical nomenclature, so proper in other respects tor facili- tating the study of science,- from the advantages of present- ing names truly picturesque, which cany along with thent the exact notion of the things they express: but the manner in which my genera were formed, occasions a slight inver- sion in the denominations, the first word of which ought to express the base of the genus, and the second the specific difference. Consequently, we must substitute, instead of the terms filiate of lime, sulphate of barytas, sulphate of irony &c, the terms filiated lime, sulphated barytes, sul- pha ted iron, &c*
But it is evident that these last denominations produce no real change in the received language ; that they require nothing else than memory ; and that they present to the mind the same images under the same traces : mineralogy does nothing more here than take the counterproof of the drawing chalked out by the chemist.
•I have not dissembled the difficulties which may be pre- sented in the way of my method; but the strongest appeared to me to arise from the state of imperfection in which che- mistry still remains with respect to the analysis of some of the. minerals. I cannot foresee, for example, the manner in which it might behest to organize and denominate the new1 genera which future discoveries will produce in the series of earthy substances. I propose the method which seems the least defective in the present slate of science. I take ad-* vantage of what has been already done, without anticipating' what still remains to be done : in short, I stop at the limit* prescribed to me by experience, expecting that future la- bours will extend them.
But it would not have been sufficient to have given to the plan of the system all the regularity and accuracy which practical knowledge requires. I thought myself obliged therefore to extend this plan, by introducing the greatest
; * Bergman, Who had a very Correct mind, and wh'o even a^umed fixed principles for the bases of his genera, called Jlnofatid lime, aerated tunc, &c'.f what xve'xilUJluated'iime, CarluHaUU lime, &e.
possible
464 Introduction to the Study of Mineralogy,
possible number of species, and by taking ad va vantage of the recent discoveries which have enriched mineralogy- I here testify my gralitude to those ingenious foreigners to whom I am indebted for some of the greatest rarities in my collection, and particularly to Messrs. Abildgaard, Manthey, Karsten, Neergaard, Esmark, Baron de Moll, Coden, and Huffman- Liang. To some of these friends I also owe some interesting observations, which have given additional value to their presents. Nothing more strongly confirms what has been so often said of the learned of all countries, namely, that they form one family, than this division of riches, which makes the distance between their respective countries disap- pear, and this communication of light which renders them constantly present with each other.
All that I have said concerns the solution of the first of the two problems I have mentioned, and its object is, the classification of substances. Now analysis, which presents data so advantageous for attaining this object, requires ope- rations frequently long and delicate, and on that account alone would become embarrassing, if it was necessary always to have recourse to it, in order to resolve the other problem, 2. e, in order to recognize the substances.
I now return to the employment of characters which, being more easily ascertained, more convenient and expe- ditious, may serve as a beacon to the minerals already classi- fied.
To judge of this according to the manner of viewing things generally adopted hitherto with respect to the solution of the problem in question, the simple description of mine- rals by the helps of their external characters contains all that is sufficient to distinguish them from each other. No- thing has more contributed to establish the reputation of the svstem in which these characters are employed, than the per- fection given to it by Werner. This ingenious mineralogist has presented it under the form of a complete system *, in which every thing in a mineral that is capable of affecting
* Vide Tabulae synsptica terminurum Systemalis oryctngnostici fferncriani, a Gregorio Wad. Hafnice, 1798. See also Berthout and Struve's Principles o£ Mineralogy, and the platei which accompany Brochant's Mineralogy.
our
Introduction to the Study of Mineralogy* 465
our senses, every thing that is tangible is carefully defined, in which all the different signs by which an attentive ob- server may recognise it are given by so many expressions, which are afterwards presented separately by themselves, in order to form the picture of each species.
This union of suffrages in favour of the system I have al- luded to, the great reputation which it has so justly acquired for its author,, would present powerful motives to prevent me from- quitting the track he has pointed out. But the plan to which I had referred the order of classification, by only admitting into it species properly so called, susceptible of a rigorous determination, led me, in order to establish their distinct characters, to profit by what they have most constant, most general, and most intimately connected with the constitution of their integrant molecules : and I have given way to the obligation of reconciling with the fixed principles I had adopted, relative to the whole of the science, the method of studying its details.
I shall here briefly mention the reasoning which directed me in the manner of arranging this method. " The picture of a species,'* I said to myself, "ought to present : 1st, a sum of characters, by the assistance of which an observer can ascertain that a mineral, which heN endeavours to class, belongs to this species : 2d, the series of the varieties which Subdivide the species. - ,
" Now the specific characters being as the fixed points whence proceeds the knowledge relative to the species, I shall exclude colours, at least when we speak of an earthy or acid substance, as fugitive variable modifications foreign to the type of the species which is the integrant molecule.
" But I shall point out among these characters the spe- cific gravity expressed numerically according to the result of experiments, and note the hardness estimated by the power which the body has to scratch another well known substance employed to serve as a term of comparison. Nor will I omit the property of double or single refraction, because it belongs to the very basis of substances, although it can be observed but very rarely when these substances are in their natural state. The lustre will be sometimes referred Vol. 33. No. 134. June 1809- Gg to,
4oo' Introduction to the Study of Mineralogy .
to, not so mirth with respect to its greater or less intensity, because in this respect it is too much subject to be modified by'accidental causes, but relatively to a certain aspect less susceptible of being disguised by the effect of the same causes, and which is, as it were, unctuous in certain mine- rals, and pearly in others, Sec. New characters will, ac- cording to circumstances, be associated with the preceding, such as electricity by heat, or phosphorescence by the action of fire.
(i I shall endeavour to define prcciselv the character which is inferred from the mechanical division of a mineral ; and instead of confining myself to announce in general if it has taken place in one, two, or three senses, will add the values of the angles which the natural joinings form among tach other; — and these joinings being as the first data for attaining th^e exact determination, either of the primitive form, or of that of the integrant molecule, it will be ne- cessary to indicate these forms, a knowledge of them being important in order to form a just idea of the species,
" Finally, I shall comprehend within the same view, the character's, the verification of which is reserved. for agents which, like the acids and caloric, change the nature of a small part of the substance, in order to assist us in becoming acquainted with the whole.
" So much for what concerns the species in general. It will afterwards be requisite to subdivide it; and in order to this, first to consider the varieties relative to the forms, as the most wrorthy of attention. Each of them will have its peculiar denomination and definition: and if this form is the produce of a regular crystallization, it will be cha- racterized by an abridged sign * composed of letters and indications of the laws of decrement upon which it depends, which, added to an exact figure, will present the best of all descriptions. I shall add the respective incidences of its faces, determined by theoretical calculation, and m which properly resides the impression borne by a crystal of.the spe- cies to which it belongs.
* I shall detail in the generalities the method of writing these signs ; and I >>ope that it will be found simple, and easy of comprehension.
3 " Iii
Introduction to the Study of Mineralogy, 467
fc In short, the modifications relative to colours, trans- parency, or opacity, will be indicated in their turns, and will form as it were the last shades of the picture. "
Thus a specific gravity of about triple that of water, a hardness equal at most to that of such bodies as slightly scratch glass, natural joints parallel to the faces and to the bases of a regular hexahedral prism, the property of dissolv- ing without effervescence in the nitric acid, will easily as- certain that a crystal provided with these properties belongs to the species of phosphated lime; and if it is a regular hexahedral prism terminated by hexahedral pyramids, the faces of which are inclined to each other by about 129°*, this particular character will point out the variety which I denominate pyramidatcd phosphated lime ; and the conse- quence already deduced from the specific character with re- spect to the nature of the crystal observed, will even then become an evidence, so much the more striking, that this measure of 129° would alone be sufficient for indicating a primitive form of phosphated lime; the analogous inclina- tion being different in the forms of the same genus which belong to other species f. If the same crystal has trans- parency, if it is of an orange colour, as we find it in Spain, the indication of these accidental circumstances will com- plete its denomination, and the observer can place it in his collection, with this inscription, phosphated lime, pyramidal orange transparent.
But this will not be a crystal ; it will be an irregular mass, in which the geometrical type of the species will have dis- appeared, and the aspect of it will excite a doubt in the ob- server, if what he sees be not a coarse carbonated lime, similar to what we call building-stone (pierre a hath). His doubts will be dispelled, when, having put a small fragment of this mass into the nitric acid, 1 e will obtain a slow and tranquil solution, or at the most accompanied oy a slight effervescence ; when, having thrown some of it in pow e'er upon lighted charcoal, he will see a fine phosphoric li^ht pro-
* More strictly speaking, 129° 13'.
f Quartz, carbonated barytes, pbgsphated lead.
G g 2 . duced
i6a Introduction to the Study of Mineralogy.
daccd at the same instant. By these traits he will also recog- nise a phosphated lime ; and on examining in detail, upon the picture of this substance, the varieties relative to indetermi- nable forms, he will learn that the name which he should give to the substance under inspection, will be thatofp/zos- phated, earthy, whitish lime.
I shall only add one reflection. We can easily conceive that a pupil, when studying with specimens in his hands, and a system founded upon external characters, can suc- ceed in ascertaining all other specimens which may present themselves to him under the same aspect. But his sy- stem having accustomed him to examine objects by the eye and touch, custom has produced an impression upon his mind; which is awakened by their presence, and the cause of which he would be much embarrassed to explain clearly by the help of language. A similar exercise will produce an analogous effect with a person who has at first employed more precise characters ; the object which he has considered attentively, after having once determined it, has only occasion to appear : it says enough to his organs, and enables him to dispense with referring to experiment, or to the use of an instrument, unless it has ceased to be fa- miliar to him. But when an unknown object conceals the same intimate composition under an aspect quite different, the student who is accustomed to take as his guide a method purely descriptive, (confined to the circle of bodies, which its author had under his eyes,) may commit a mistake, while another, with the assistance of the first methods, will not be imposed on by a false appearance : and this is a new proof of the preeminence of these characters, which, be- longing more closely to the nature of substances, and mark- ing those points which are least likely to escape a common observer, are susceptible of a much greater latitude, and have the double advantage of being applied to our acquired knowledge, and, as it were, to go before those which will subsequently present themselves*.
After
* It would be desirable to endeavour to add new physical and chemical characters, simple, and easy to be determined, to those which we already
know.
Introduction to the Study of Mineralogy, 46Q
After having presented the picture of the characters, the assemblage of which distinguishes the species^ and the series of the varieties which subdivide it, I have added annotations which contain as it were its history. Here will be found the indication of its principal situations in (he earth, and that of the substances which most generally accompany it. I afterwards detail the various opinions which have been en- tertained as to the nature of the mineral which constitutes it ; and I thought that it would not be useless to explain, when I had an opportunity, what appeared to have deceived former observers, and how the transition from error to truth was effected. Here again naturally comes the explanation of the phenomena which the mineral is susceptible of presenting, in the event of its enjoying Some interesting property. I shall be the more respected by my readers, when I inform them that, in my applications of the subject to the mechani- cal and healing arts, I have been furnished with valuable assistance by M. Chaptal in the former department, and M. Halle in the latter.
The point of view under which I have considered mine- ralogy in this treatise, required that the reader should be prepared for the study of the method, by a detail of the knowledge which was resorted to in forming the plan. I have paid every attention to fulfilling this object in a series of details, in which I develop the principles proper for clear- ing up the entrance upon the science. T have presented in two ways, the theory of the laws to which the structure of crystals is subjected ; the one by simple reasoning aided by figures, which render sensible to the eye the mechanism of this structure; the other ill a, separate article, by the aid of mathematical analysis, by giving to the results the whole generality which the subject requires *,
I ought
know. I have found several, which will be pointed out in this treatise ; and I am persuaded that we shall succeed, after continued inquiries, to augment the number considerably.
* I am far from thinking that the numerous applications which I have made of this theory to the crystals examined by me; possess all the same degree of exactness. The difficulty of determining, in several of these crystals, the true direction of the natural joinings, the smallness of others, the defects
G g 3 which,
470 Introduction to the Study of Mineralogy .
T ought not to omit how much I am indebted to the in- telligence and assiduity of those who have traced the pro- jections relative to crystallography, and to the theories which flow from mineralogical science. The idea of this great work was conceived by M. Brochant, mining engineer, who has begun to realize it. Several other engineers and scientific men have endeavoured to complete what he had begun. M. Tremery, to whom belong, among other things, almost all the projections depending upon calculation, which he perfectly well understands, has carried into their execution the intelligence and accuracy so necessary for enabling the eye easily to catch the respective positions of the different lines, the constructions of which form the whole. Messrs. Cordier, Lefroy, Gallois, Houry, Depuch, Cressac, Du- cros, and Hericart, have also given proofs of zeal and talent, in the drawing of figures which relate to the different classes of minerals. Such is the masterly manner in which they have represented, relative to a nucleus which has constantly the same position, the different secondary forms which are so many modifications of it, that we perceive, as at one glance, the relations of these forms, both with each other and with their common nucleus : this is a kind of graphic treatise of the laws to which the structure is subjected.
The School of Mines has offered me another resource of great value, on the subject of the very basis of my work. Placed in an isolated situation for many years, and limited to my own exertions, I occupied myself, in solitude, with arranging the materials for my work ; with determining, by observation and theory, all the crystalline forms which I was able to procure ; ascending to the causes of the most interesting phaenomena presented by minerals ; drawing, from the properties of these bodies, characters proper for distin- guishing them, and collecting every thing relative to their history, &c. . 1 had even already traced the plan of their
which, upon those of a more sensible volume, would alter the level of the forces, are so manv causes of uncertainty, which ought to influence the solu- tions of the problems. It is very probable, that observations subsequently made under more favourable circumstances will serve to rectify several of my data, and place the results of calculation on a par with those of N lture.
methodical
Analysis ofihe Mtcdnique Celeste of M. La Place. 471 methodical distribution, which was nearly the same with what I have given here. But in the midst of this complica- tion of inquiries, directed towards so many various objects, there are always some which arc attended with doubts, and there are details which either escape us or remain imperfect. I have said enough to convince my readers how advantageous I found it to be placed in the same establishment with Gil- let, Lelievre, Lefebvre, Dolomieu, Brogniart, Vauquelin, Coquebert, Tonnellier, from whom 1 imbibed informa- tion and advice. Several important points have been fully and coolly discussed among us ; and when the sentiments which flow from a perfect intimacy are freely given in friendly discussions, they produce reflections and observa- tions of great value. The conflict of opinions only paves the way for a better understanding among the disputants, and the cause of true science is uniformly promoted by such discussions.
LXXXIII. Analysis of the Mecanique Celeste of M. La Place. By M. Biot.
[Continued from p. 270.]
Book Second.
After having developed the laws of motion of bodies when actuated by known forces, the author proposes to as- certain what should be the general cause of the celestial mo- tions, in order to reconcile them with actual observations. Setting out therefore with the consideration of the. ellip- tical motion of the planets, and the laws discovered by- Kepler, he concludes that the force which attracts the planets and comets is directed towards the centre of the sun, that it is reciprocally as the square of their distances, and that it only differs in different bodies in proportion to these di- stances. The motion of the satellites around their planets presenting nearly the same phenomena as that of the planets round the sun, the satellites are attracted towards the planets and the sun, by forces reciprocally as the squares of their distances. This law extends to satellites,
Gg4 whose
472 Analysis of the Mccanique Cflestc of M. La Place.
whose orbits have not yet been ascertained to be elliptic ) and it follows from this, that, for each system of satellites, the squares of the times of their .revolutions are as the cubes of their mean distances from the centre of the planet: the earth having but one satellite, we cannot apply this con- sideration to it ; but the author shows that, if we determine the lunar parallax according to the terrestrial experiments upon gravity, and with the hypothesis that the recipro- cal gravitation is as the square of the distance, the result obtained by this way is perfectly conformable to the observa- tions, whence it follows, that the attractive force of the earth is the same as that of all the celestial bodies. These conclu- sions give" rise to several important reflections, from which the author infers this general consequence, that the particles of matter attract each other in the direct ratio of the masses, and the inverse ratio of the square of the distances.
Conformably to this theory, the author establishes the differential equations which determine the motion of a system of bodies subjected to their mutual attraction, and develops the small number of exact integrals which they have hitherto been able to obtain : as observation only makes us acquainted with the relative motions, he gives the fbfc» mulae for the motion of a system of bodies subject to the laws of gravitation round a body considered as the centre of their motions, and develops the exact integrals which we know how to deduce from them. In order to go further, recourse must be had to the methods of approximation, and we musUprofit by the facilities offered for this purpose by the constitution of the system of the world : the author shows that, according to this constitution, the satellites of the planets are moved nearly as if they only obeyed the action of the planet ; and the motion of the centre of gravity of a planet, and of its satellites, is very nearly the same as if each of these bodies was collected into its centre. He af- terwards proceeds to inquire into the attractive properties of spheroids, and establishes some general propositions on this head, from which it follows that a poiyt placed in the interior of a s pheric stratum is equally atttacted from all parts, and that a point without the stratum is attracted by
it
Analysis of the Mecanique Celeste of M> La Place. 473
it as if its mass were entirely collected to its centre ; pro- perties which also take place with respect to globes formed of concentric layers, of density variable from the centre to the circumference: the author inquires what are, the laws of attraction in which these effects subsist ; and he proves that, among the infinite number of laws which render the attrac- tion very small at great distances, the law of Nature is the only one in which a spheric stratum attracts a poinjt placed without it, as if it was all collected to its centre: he proves also, that this law is the only one in which the action of the layer upon a point placed within it is nothing : he also makes a second application of the same formulae, to the case in which the attracting body is a cylinder whose base is a re- entering curve, the length of which is infinite; he demon- strates that, when this curve is a circle, the action of the cy- linder upon a point without it, is reciprocally as, the distance from its axis to this point; and that> if the attracted point is situated in the interior of a circular cylindric layer of a constant thickness, it is equally attracted from all parts. The formulas of the motion of a body give rise to some very remarkable conditional equations : the author develops them, and points out their use for verifying the calculations of the theory, and the theory itself of universal gravity ; after which he presents the various transformations which it may be most frequently useful to subject the differential equa- tions to, of the motion of any system of bodies animated by their mutual attraction. The bodies which compose the so- lar system, moving nearly as if they obeyed only the prin- cipal force which animates them, and the perturbat'ing forces not being very considerable, the author previously gives as a first approximation, the exact determination of the motion of two bodies which attract each other directly in the ratio of the masses, and inversely as the square of the distances : he explains successively three different methods of integrating differential equations relative to this hypothesis: the second of these methods is founded upon an elegant theorem rela- tive to the integration of differential equations of the first degree, and of any order whatever. The third, which makes t\\e required integrals of one equation only to depend on
partial
474 Analysis of the Mecanique Celeste ofM. La Place,
partial differences, has the advantage of giving the arbitrary quantities in functions of the co-ordinates, and of their first differences, which is frequently useful : the author deduces from it the relations which take place between these arbi- trary quantities, and the elements which determine the na- ture of the conic section and its position in space : finally, he integrates the differential equation which gives the time in a function of the radius vector; and the motion of two bodies is thus determined by three equations, between the eccentric anomaly, the true anomaly, the mean anomaly, and the radius vector of the orbit : these equations being of a nature not capable of being resolved except by approxima- tion, the author details some general theorems upon the re- duction of functions into series; and applying these results to the elliptical motion of the planets, he deduces from them the values of the eccentric anomaly, the true anomaly, and of the radius vector, in convergent series of the sines and co- sines of the mean anomaly: by referring the motion of the planet to a fixed plane a little inclined to that of the orbit, these series furnish the means of determining by approxi- mation the latitude and longitude of the planet with respect to the fixed plane, as well as the projection of the radius of the orbit upon the same plane. The author explains the the- ory of motion in a very eccentric ellipsis, and thence de- duces the theory of the parabolic motion applicable to co- mets : he afterwards considers the hyperbolic motion ; and then arriving at Kepler's law, according to which the squares of the revolutions of different planets are to each other as the cubes of the transverse axes of their orbits, he shows that this law is not accurately true, and that it only takes place when we neglect the action of the planets upon each other, and upon the sun, and when we consider their masses as infinitely small with respect to that of the sun. He shows the use of these results in determining the ratios of the masses of the planets which have satellites, to the mass of the sun. v
After having'detailed the theory of elliptic motion, and the method of calculating it by converging series in the two cases of Nature, that of orbits almost circular, and that of
orbits
Analysis of the MBcanique Celeste of M* La Place. 475 orbits very much elongated, the author proceeds to determine the elements of these orbits : he shows in the first, place how we might deduce them from the circumstances of primitive motion, if these circumstances were known ; and it is re- markable that the direction of this motion does ne>t influence the nature of the conic section. These researches produce the discovery of the relation which exists between the trans- verse axis of the orbit, the chord of the elliptic arc, the sum .of the extreme radii vectores, and the time taken to de- scribe this arc.
As the observations do not make known the circumstances attending the primitive motion of the celestial bodies, we cannot determine from this supposition the elements of theif orbits: it is necessary for this purpose to compare their re- spective positions, observed at different epochs, with each other : this is what we may do at all times with respect to the planets, which we mav observe without interruption ; but it is not the case with comets, which are only visible to us in that part of their orbit which is nearest to the sun : it is important, therefore, to be able to determine the elements of the orbit of a comet from the circumstances attending its appearance. In order to attain this, the author in the first place gives converging formulae, which make known for a given time, and according to any number of adjacent ob- servations, the geocentric longitude and latitude of the co- met, as well as their first and second differences divided by the corresponding powers of the element of the time: he shows that, by supposing these quantities to be known for a given time in a system of bodies subjected to their mutual attraction, we may easily, and without the assistance of in- tegration, deduce therefrom the elements of the orbits.
After having detailed these methods to the utmost extent that is necessary, and given them all the perfection of which they are susceptible ; attending also in a very simple manner to the eccentricity of the terrestrial orbit, the author applies them to the case of Nature, in which the orbits of comets are ellipses greatly elongated, which are sensibly confounded with the parabola towards the perihelion, which admits of our considering their transverse axes as infinite : this cir^
476 Reply to Mr. Barlow* s Article
cumstance, which makes known dpriori one of the elements of the orbit, introducing a new equation, it follows from it that the determination of parabolic orbits of comets con- duces to more equation! than unknown quantities, which gives room for various methods of calculating them. After having ascertained that method which ought to give the greatest precision, the author enters upon the subject at full length, and divides it into two pars: in the first he deter- mines nearly the perihelion distance of the comet, and the time of its passage by the perihelion : in the second he gives the method of correcting these two elements by means of three observations taken at a distance from eaoh other, and he deduces all the others from them. There exists a peculiar case in which the o^bit of the comet may be rigorously determined : it is that case wherein the comet has been observed in its two nodes : after having examined it, the author gives the corrections necessary to be made in the ele- ments calculated in the parabola to obtain the correspond- ing elements in the ellipsis : these inquiries, applied to co- mets, furnish the method of determining nearly the dura- tion of their revolutions, when we have a -great number of very exact observations, both before and after the passage by the perihelion. The method explained has the double advantage of correcting, by the number of observations, the influence of their errors, and of giving the elements by a rigorous analysis, simply by making the approximations to fall upon those data which are given by observation.
[To be continued.]
LXXXIV. Reply to Mr. Barlow's Article on Floating Bodies. By G. Orr, Esq., of Buckingham Place, Fitzroy Square.
To Mr. Til loch, — Sir, In sending for your Magazine of March last a short essay on the subject of barges, timber, &c, floating down rivers, streams, or currents, it was not my intention to court a paper war. But Mr. Barlow * having asserted that I did not
* Philosophical Magazine-for April 1809, p. 300. y
under-
on Floating Bodies. 477
understand the subject, I beg to be allowed to trespass again on your indulgence.
I am persuaded that no person who has investigated the subject, will deny that all water in motion descends an in- clined plane, and that bodies floating in it are actually de- scending an inclined plane also, being influenced by two- causes in their progress; first, by the motion communicated to them by the fluid in which they float ; and secondly, by their own weight arising from the inherent property of gra- vity, which, whether the body be more or less specifically heavy, is immutable, and peeuiiar to all matter. — In vacuo, as every one knows, a feather and a piece of gold will de- scend with equal velocity, and pass through equal spaces in equal times; but in air or water, the progress of bodies spe- cifically different, will vary according to their specific gra- vity; the lighter body, possessing. less power to overcome opposition, must of course be slower in its progress. — If the wood and metal balls, which [ mentioned, were let fall in vacuo, or if they were mathematically polished, and passed down an inclined plane so polished and placed \n vacuo, they would both descend with the same velocity; but in open air, and on a rough surface, the heaviest body being possessed of greater power, arising from a greater quantity of matter, viz. from greater specific gravity, it will have the greater power in overcoming opposition, and will pass on with the more rapid motion ; but still in both bodies the principle of gravity is the same.
Mr. B. says that 1 am mistaken in making a comparison between balls of different weights rolling down an inclined plane, and barges or beams of different weights floating down a running stream : that is, as I understand him, he does not like the comparison, and he says the balls move through a medium perfectly at rest, but the barges, &c, through a medium in motion. — I beg leave to observe to Mr. B., that the air or atmosphere is never perfectly at rest, except when all its particles are in equilibrio, which is sel- dom the case, and never generally so. Balls may meet cur- rents of air, or may overtake air moving slower than them- selves: in either case, their motion must bq retarded more or
less,
478 Reply to Mr. Barlow's Article on Floating Bodies,
less, the same as beams floating in running water may be retarded by encountering irregular or slower motions in wafer.
Mr. B. illustrates his opinion by supposing a beam of timber loaded at one end, placed in running water, and inov'mg parallel to itself, or, in other words, having an equal velocity at both ends. But this is absolutely impossible in the nature or' things. The beam thus loaded cannot preserve its parallelism for an instant. It must obey the laws of gra- vity, and instantaneously begin to change its situation, the heavy end getting foremost. It would be just as impossible that such a loaded beam could preserve its parallelism, as that a ruler loaded at one end, and placed parallel on an in- clined plane, should rest in that position, or that a cone should keep in such a situation without force. — Mr. B. says again, M if a beam should meet any resistance, that end which is heaviest will oppose it with the greatest effect." Certainly, because it contains the greatest quantity of mat- ter : But will not the heavier end always go foremost with- out any resistance ? In considering this subject, allowance must be made for currents, eddies, &c. ; but to understand it the more clearly, it would be best to consider the floating bodies as passing down a regular stream.
Mr. B. seems to me to confound weight, which is only the result of gravity, and of a greater quantity of matter, with gravity itself; for though one end of a beam be heavier than the other, and the beam consequently will float with the heavier end foremost, yet the inherent and inseparable property of gravity is the same in both ends of the beam. I am, sir, your obedient servant,
G. Our.
P. S. I do conceive that all bodies floating with the stream, and which have a heavy and light end, will become depressed at their heavier end, and be borne parallel to the plane on which the water moves, — in all such cases adapting them- selves to the inclination of the plane or bed on which the water runs.
LXXXV. The
[ 479 ]
LXXXV. The Bakerian Lecture. An Account of some new analytical Researches on the Nature of certain Bodies, particularly the Alkalies, Phosphorus, Sulphur, Carlo- naceous Matter, and the Acids hitherto undecomposed ; with some general Observations on Chemical Theory. By Humphry Davy, Esq., Sec. R.S., F.R.S. Edin., and M.R.I.A.*
I. Introduction.
In the following pages, I shall do myself the honour of lay- ing before the Royal Society, an account of the results of the different experiments, made with the hopes of extending our knowledge of the principles of bodies by the new powers and methods arising from the applications of electricity to chemistry, some of which have been long in progress, and others of which have been instituted since their last session.
The objects which have principally occupied my attention, % are the elementary matter of ammonia, the nature of phos- phorus, sulphur, charcoal, and the diamond, and the con- stituents of the boracic, fluoric, and muriatic acids.
Amongst the numerous processes of decomposition, which I have attempted, many have been successful; and from those which have failed, some new phasnomena have usually resulted which may possibly serve as guides in future in- quiries. On this account, I shall keep back no part of the investigation, and I shall trust to the candour of the Society for an excuse for its imperfection.
The more approaches are made in chemical inquiries to- wards the refined analysis of bodies, the greater are the ob- stacles which present themselves, and the less perfect the results.
AH the difficulties which occur in analysing a body, are direct proofs of the energy of attraction of its constituent parts. In the play of affinities with respect to secondarv compounds even, it rarely occurs that any perfectly pure or unmixed substance is obtained ; and the principle applies still more strongly to primary combinations.
The first methods of experimenting on new objects like- * From Philosophical Transactions for 1809. Part I.
wise
480 On some new analytical Researches
wise are necessarily imperfect; novel instruments are de- manded, the use of' which is only gradually acquired, and a number of Experiments of the same kind must be made, be- fore one is obtained from which correct data for conclusions
II. Experiments on the Action of Potassium on Ammonia, and Observations on the Nature of these two Bodies. In the Bakerian lecture, which I had the honour of read- ing before the Society, November 19, 1807, I mentioned that, in heating potassium strongly in ammonia, I found that there was a considerable increase of volume of the gas, that hydrogen and nitrogen were produced, and that the potas- sium appeared to be oxidated ; but this experiment, as I had not been able to examine the residuum with accuracy, I did not publish. I stated it as an evidence, which I intended to pursue more fully, of the existence of oxygen in ammonia.
In a paper read before the Royal Society last June, which they have done me the honour of printing, I have given an account of various experiments on the amalgam from am- monia, discovered by Messrs. Berzelius and Pontin, and in a note attached to this communication I ventured to con- trovert an opinion of MM. Gay Lussac and Thenard, with respect to the agency of potassium and ammonia, even on their own statement of facts, as detailed in theMoniteur for May 27, 1808.
The general obscurity belonging to these refined objects of research, their importance and connection with the whole of chemical theory, have induced me since that time to ap- ply to them no inconsiderable degree of' labour and attention ; and the results of my inquiries will, I trust, be found not only to confirm my former conclusions ; but likewise to offer some novel views.
In the first of these series of operations on' the action of potassium on ammonia, I used retorts of the green glass; I then, suspecting oxygen might be derived from the metallic oxides in the green glass, employed retorts of plate glass ; and 'ast of all, I fastened the potassium upon trays of pla- tina, or iron, which were introduced into the glass retorts
furnished
on the Nature of certain Bodies* 48 1
furnished with stop cocks. These retorts were exhausted by an excellent air pump, they were filled with hydrogen, ex- hausted a second time, and then filled with ammonia from an appropriate mercurial gas holder*. In this way the gas was operated upon in a high degree of purity, which was always ascertained ; and all the operations performed out of the contact of mercury, water, or any substances that could interfere with the results.
I at first employed potassium procured by electricity ; but I soon substituted for it the metal obtained by the action of ignited iron upon potash, in the happy method discovered by MM. Gay Lussac and Thenard, finding that it gave the same results, and could be obtained of an uniform quality f, and in infinitely larger quantities, and with much less labour and expense.
When ammonia is brought in contact with about twice its weight of potassium at common temperatures, the metal loses its lustre and becomes white, there is a slight diminu- tion in the volume of the gas ; but no other effects are pro- duced. The white crust examined proves to be potash, and the ammonia is found to contain a small quantity of hydro- gen, usually not more than equal in volume to the metal. On heating the potassium in the gas, by means of a spirit lamp applied to the bottom of the retort, the colour of the crust is seen to change from white to a bright azure, and this gradually passes through shades of bright blue and green into dark olive. The crust and the metal then fuse together; there is a considerable effervescence, and the cru3t passing
* A representation of the instruments will be given in the next Number of our Magazine.
f When the potash used for procuring potassium in this operation was very pure, and the iron turnings likewise very pure and clean, and the whole apparatus free from ahy foreign matters, the metal produced differed very little, in its properties, from that obtained by the Voltaic battery. Its lustre, ductility, and inflammability were similar. Its point Of fusion and specific gravity were, however, a little higher, it requiring nearly 130° of Fahren- heit to render it perfectly fluid, and being to water as 7960 to 10000, at 60° Fahrenheit. This I am inclined to attribute to its containing a minute pro- portion of iron.
Vol. 33. No. 134. June 1809- Hh off
482 On some new analytical Researches
off to the sides, suffers the brilliant surface of the po- tassium to appear. When the potassium is cooled in this state, it s aga n covered with the white crust. By heating a second time, it swells considerably, becomes porous, and appears crystallized, and of a beautiful azure tint ; the same series of phenomena, as those before described, occur in a continuation of the process, and it is finally entirely con- verted into the dark olive- coloured substance.
In this operation, as has been stated by MM. Gay Lussac and Thenard, a gas which gives the same diminution by detonation with oxygen as hydrogen is evolved, and am- monia disappears.
The proportion of the ammonia which loses its clastic form, as I have found by numerous trials, varies according as the gas employed contains more or less moisture.
Thus eight grains of potassium, during its conversion into the olive- coloured substance, in ammonia saturated with water at 63° Fahrenheit, and under a pressure equal to that of 29* 8 inches of mercury, had caused the disappearance of twelve cubical inches and a half of ammonia; but the same quantity of metal acted upon under similar circumstances, except that the ammonia had been deprived of as much moisture as possible by exposure for two days to potash that had been ignited, occasioned a disappearance of sixteen cu- bical inches of the volatile alkali.
Whatever be the degree of moisture of the gas, the quan- tities of inflammable gas generated have always appeared to me to be equal for equal quantities of metal. MM. Gay Lussac and Thenard are said to have stated, that the proportions in their experiment were the same as would have resulted from the action of water upon potassium. In my trials, they have been rather less. Thus, in an experiment conducted with every possible attention to accuracy of manipulation, eight grains of potassium generated, by their operation upon water, eight cubical inches and a half of hydrogen gas: and eight grains from the same mass, by their action upon am- monia, produced eight cubical inches and one-eighth of in- flammable gas. This difference is inconsiderable; yet I have
always
vn the Nature of certain Bodies, 483
always found it to exist, even in cases wnere the ammonia has been in great excess, and every part of the metal appa- rently converted into the olive-coloured substance.
No other account of the experiments of MM. Gay Lus- sac and Thenard has, I believe, as yet been received m this country, except that in the Moniteur already referred to 3 and in this no mention is made of the properties of the sub- stance produced by the action of ammonia on potassium. Having examined them minutely and found them curious, I shall generally describe them.
1. It is crystallized, and presents irregular facets, which are extremely dark, and in colour and lustre not unlike the protoxide of iron ; it is opaque when examined in large masses, but is semi-transparent in thin films, and appears of a bright brown colour by transmitted light.
2. It is fusible at a heat a little above that of boiling water, and if heated much higher, emits globules of gas.
3. It appears to be considerably heavier than water, for it sinks rapidly in oil of sassafras.
4. It is a non-conductor of electricity.
5. When it is melted in oxygen gas, it burns with great vividness, emitting bright sparks. Oxygen is absorbed, ni- trogen is emitted, and potash, which from its great fusibility seems to contain water, is formed.
6. When brought in contact with water, it acts upon it with much energy, produces heat, and often inflammation, and evolves ammonia. When thrown upon water, it dis- appears with a hissing noise, and globules from it often move in a state of ignition upon the surface of the water. It rapidly effervesces and deliquesces in air, but can be pre- served under naphtha, in which, however, it softens slowly, and seems partially to dissolve. When it is plunged under water filling an inverted jar, by means of a proper tube, it disappears instantly with effervescence, and the non-ab- sorbable elastic fluid liberated is found to be hydrogen gas.
By far the greatest part of the ponderable matter of the ammonia, that disappears in the experiment of its action upon potassiumyeTifjently exists in the dark fusible product. On weighing a tray containing six grains of potassium, be- ll h 2 fore
484 On some new analytical Researches
fort and after the process, the volatile alkali employed having been very dry, I found that it bad increased more than two grains ; the rapidity with which the product acts upon mois- ture, prevented me from determining the point with great minuteness ; but I doubt not, that the weight of the olive* coloured substance and or' the hydrogen disengaged precisely equals the weight of the potassium, and ammonia consumed.
MM. Gay Lussac and Thenard* are said to have procured from the fusible substance, by the application of a strong heat, two fifths of the quantity of ammonia that had disap- peared in their first process, and a quantity of hydrogen and nitrogen in the proportions in which they exist in ammonia, equal to one fifth more.
My results have been very different, and the reasons will, I trust, be immediately obvious.
When the retort containing the fusible substance is ex- hausted, filled with hydrogen and exhausted a second time, and heat gradually applied, the substance soon fuses, effer- vesces, and, as the heat increases, gives off a considerable quantity of elastic fluid, and becomes at length, when the temperature approaches nearly to dull redness, a dark gray- solid, which, by a continuance of this degree of heat, does not undergo any alteration.
In an experiment, in which eight grains of potassium had absorbed sixteen cubical inches of well dried ammonia in a glass retort, the fusible substance gave off twelve cubical inches and half of gas, by being heated nearly to redness, and this gas analysed, was found to consist of three quarters of a cubical inch of ammonia, and the remainder of elastic fluids, which, when mixed with oxygen gas in the proportion of 6 j to fi, and acted upon by the electric spark, diminished to 5\. The temperature of the atmosphere, in this process, was 57° Fahrenheit, and the pressure equalled that of 30*1 inches of mercury.
In a similar experiment, in which the platina tray contain- ing the fusible substance was heated in a polished iron tube,
* No notice is taken of the apparatus used by MM. Gay Lussac and The- nard in the Moniteur; but, from the tenour of the details, it seems that they must have operated in jjlas.3 vesseL in the wav hi retur'ore adopted over mercury,
filled
07i the Nature of certain Bodies, 485
filled with hydrogen gas, and connected with a pneumatic apparatus containing very dry mercury, the quantity of elastic fluid given off, all the corrections being made, equalled thir- teen cubical inches and three quarters, and of these a cubical inch was ammonia j and the residual gas, and the gas in- troduced into the tube being accounted for, it appeared that the elastic fluid generated, destructible by detonation whh oxygen, was to the indestructible elastic fluid, as li'5 to 1.
In this process, the heat applied approached to the dull red heat. The mercury, in the thermometer, stood at 6^ Fahrenheit, and that in the barometer at 30-3 inches.
In various experiments on different quantities of the fu- sible substance, in some of which the heat was applied to the tray in the green glass retort, and in others, after it had been introduced into the iron tube ; and in which the tem- perature was sometimes raised slowly and sometimes quickly, the comparative results were' so near these that I have de- tailed, as to render any statement of them superfluous.
A little more ammonia, and rather a larger proportion of inflammable gas*, were in all instances evolved when the iron tube was used, which I am inclined to attribute to ihe following circumstances. When the tray was brought through the atmosphere to be introduced into the iron tube, the fusible substance absorbed a small quantity of moisture from the air, which is connected with the production of am- monia. And in the process of heating in the retort, the green glass was blackened, and I found that it contained a very small quantity of the oxides of lead and iron, which must have caused the disappearance of a small quantity of hydrogen.
MM. Gay Lussac and Thenard, it appears from the state- ment, had brought the fusible substance in contact with mercurv, which must have given to it some morsture ; and whenever this is the case, it furnishes by heat variable quantities of ammonia. In one instance, in which I heated the fusible substance from nine grains of potassium, in ft
* The average of six experiments made in a tube of iron, is ?-4 of inflam- mable pas to 1 of uninflammable. The avera-e of three made in green glas» retorts, is 2-3 to 1.
H h 3 retort
486 On some neiu analytical Researches
retort that had been filled with mercury in its common statd or dryness, [obtained seven cubical inches or' ammonia, as the first product; and in another experiment which had been made with eight grains, and in which moisture was purposely introduced, I obtained nearly nine cubical inches ol ammonia, and only four of the mixed gases.
I am inclined to believe, that if moisture could be intro- duced only in the proper proportion, the quantity of am- monia generated, would be exactly equal to that which dis- appeared in the first process.
This idea is confirmed by the trials which I have made, by heating the fusible substance with potash, containing its wa- ter of crystallization, and muriate of lime partially dried*.
In both these cases, ammonia was generated with great rapidity, and no other gas, but a minute quantity of inflam- mable gas, evolved, which was condensed by detonation with oxygen with the same phaenomena as pure hydrogen.
In one instance, in which thirteen cubical inches of am- monia had disappeared, I obtained nearly eleven and three quarters by the agency of the water of the potash ; the quan- tity of inflammable gas generated, was less than four tenths of a cubical inch.
In another, in which fourteen cubical inches had been absorbed, I procured by the operation of the moisture of muriate of lime, nearly eleven cubical inches of volatile al- kali, and half a cubical inch of inflammable gas ; and the differences, there is every reason to believe, were owing to an excess of water in the salts, by which s^orne of the gas was absorbed.
Whenever, in experiments on the fusible substance, it has been procured from ammonia saturated with moisture, I have always found that more ammonia is generated from it by mere heat ; and the general tenourofthe experiments inclines me to believe, that the small quantity, produced in experi-
* If water, in its common form, is brought in contact with the fusible sub- stance, it is impossible to regulate the quantity, so as to gain conclusive re- sults, and a very slight excess of water causes the disappearance of a very large quantity of the ammonia generated. In potash and muriate of lime, in certain states of dryness, the water is too strongly attracted by the saline matter to be given off, except for the purpose of generating the ammonia.
ments
on the Nature of certain Bodies. 487
ments performed in vacuo, is owing to the small quantity of moisture furnished by the hydrogen gas introduced, and that the fusible substance, heated out of the piesence of moisture, is incapable of producing volatile alkali.
MM. Gay Lussac and Thenard, it is stated, after having obtained three fifths of the ammonia or its elements that had disappeared in their experiment, by heating the product, procured the remaining two fifths, by adding water to the residuum, which after this operation was found to be potash. No notice is taken of the properties of this residuum, which, as the details seem to relate to a single experiment, probably was not examined ; nor, as moisture was present at the be- ginning of their operations, could any accurate knowledge of its nature have been gained.
I have made the residuum of the fusible substance after it has been exposed to a dull red heat, out of the contact of moisture, an object of particular study, and I shall detail its general properties.
It was examined under naphtha, as it is instantly de* stroyed by the contact of air.
1. Its colour is black, and its lustre not much inferior to that of plumbago.
2. It is opaque even in the thinnest films.
3. It is very brittle, and affords a deep gray powder.
4. It is a conductor of electricity.
5. It does not fuse at a low red heat, and when raised to this temperature, in contact with plate glass, it blackens the glass, and a grayish sublimate rises from it, which likewise blackens the glass.
6. When exposed to air at common temperatures, it usually takes fire immediately, and burns with a deep red light.
7. When it is acted upon by water, it heats, effervesces most violently, and evolves volatile alkali, leaving behind nothing but potash. When the process is conducted under water, a little inflammable gas is found to be generated. A residuum of eight grains giving in all cases about ^o of a cubical inch.
8. It has no action upon quicksilver.
9. It combines with sulphur and phosphorus by heat,
H h 4 without
488 On the Agency of Electricity on
without any vividness of effect, and the compounds are highly inflammable, and emit ammonia, and the one phos- phuretted and the other sulphuretted hydrogen gas, by the action of water.
[To be continued.]
LXXXVI. On the Agency of Electricity on Animal Secre- tions. By VVm. H. Wollaston, M.D., Sec. R.S.
At the time when Mr. Davy first communicated to me his important experiments on the separation and transfer of che- mical agents by means of the Voltaic apparatus, which was in the autumn of 1806, I was forcibly struck with the proba- bility that animal secretions were affected by the agency of a similar electric power ; since the existence of this power in some animals was fully proved by the phsenomena of the Torpedo, and of the Qymnotus Electricus ; and since the universal prevalence of similar powers of lower intensity in other animate was rendered highly probable by the extreme suddenness with which the nervous influence is communi- cated from one part of the living system to another.
And though the separation of chemical agents, as well as their transfer to a distance, and their transition through solids, and through fluids which might be expected to op- pose their progress, had not then been effected but by power- ful batteries ; yet it appeared highly probable that the weakest electric energies might be capable of producing the same effects, though more slowly in proportion to the weakness of the powers employed.
I accordingly at that time made an experiment for eluci- dating this hypothesis, and communicated it to Mr. Davy and to others of my friends. But though it was conclusive- with regard to the sufficiency of very feeble powers, it did not appear deserving of publication, until I could adduce some evidence of the actual employment of such means in the animal ceconmy.
As I am not accustomed to making experiments on living
animals,
Animal Secretions. 4 so,
animals, I had deferred pursuing the application of my th?* ory, until it was again brought back to my mind by finding that the same thought had occurred to Dr. Young. And as it has already been printed some month's in the Syllabus of his Course of Medical Lectures, I had for the present re- linquished all thoughts of recording conjectures, which, if not well founded, might retard the progress of science.
But since some experiments relating to the same inquiry are now about to be published by Mr. Home, it may perhaps be of use to add my experiment to the general stock of in- formation, although I have not myself improved upon it by any further consideration, and am not yet enabled to con- firm the hypothesis, which it appeared to support, by any new arguments.
The experiment was conducted as follows :
I took a piece of glass tube about three quarters of an inch in diameter and nearly two inches long, open at both ends, and covered one of them with a piece of clean bladder. Into this little vessel I poured some water in which I had dis- solved t4tt of its weight of salt; and after placing it upon a shilling with the bladder slightly moistened externally, I bent a wire of zinc so, that while one extremity rested on the shilling the other might be immersed about an inch in the water. By successive examination of the external sur- face of the bladder, I found that even this feeble power oc- casioned soda to be separated from the water, and to tran- sude through the substance of the bladder. The presence of alkali was discernible by the application of reddened litmus- paper after two or three minutes, and was generally mani- fest even by the test of turmeric before five minutes had ex- pired.
The efficacy of powers so feeble as are here called into action, tends to confirm the conjecture that similar agents may be instrumental in effecting the various animal secre- tions, which have not yet been otherwise explained. The qualities of each secreted fluid may hereafter instruct us as to the species of electricity that prevails in each organ of the body.
For instance, the general redundance of acid in urine,
though
4 1)0 Report of the City and Finslury Dispensaries,
though secreted from blood that is known to be alkaline, appears to indicate in the kidneys a state of positive electrU city; and since the proportion of alkali in bile seems to be greater than is contained in the blood of the same animal, it is not improbable that the secreting vessels of the liver may be comparatively negative.
With such views of the vital functions it becomes an in- teresting subject of inquiry, what other organs may also be considered as permanently different in their state of electri- city, and what others may possibly be subject to temporary states of opposite electric energies, and may, by means of such relation, produce the most powerful effects in the ani- mal ceconomy.
JJCXXVII. Report of Surgical Cases In the City and Finslury Dispensaries for October, November, and December, 1S08. With the Dissection of a singular Foetus. By John Taun- ton, Esq, , '
In October, November, and December, there were admitted
on Ihe books of the City and Finsbury Dispensaries 73S surgical patients.
Cured or relieved — 321
Died — — 7
Tr regular — — 3
Under treatment — 407
738
During the year 1 808, there have been admitted on the books of the City Dispensary 3105 patients. Cured or relieved — 3069 Discharged for irregularity 5
Pied — — 31
3105
The expense of the City Dispensary for the year 1808, in- cluding every item of disbursement, amounts only to 575/. 95. 1 d.; a sum comparatively small to the benefits derived by the lower order of society, by persons incapable of providing
either
Report of the City and Flnshiry Dispensaries. 491
either, attendance or medicine otherwise. The few deaths are perhaps the strongest proof of the advantage of medical establishments of this kind, where the patients are treated in the midst of their families, and where they enjoy the kind and affectionate offices of the healthful. . ", To contrast dispensaries with hospitals might seem in- vidious; hut the dispensary has this peculiar advantage, that it retains the unhappy sufferers in the bosom of their fami- lies : — Judize of this, vou who have felt the miseries of part- ing with those who are nearest and dearest to you, and who have experienced the anxious cares and sympathies of an affectionate husband or wife, of a tender parent or child, in the day of distress ! — Judge of it also, ye who are acquainted with the nature of the animal ceconomy ; — with the influence of the mental faculties and passions over the body; — with the injurious effects of depressing, and the beneficial and important consequences of soothing, passions in the alleviation or cure of disease*."
Mrs. has had several children, none of whom have
lived : — she was taken in labour jat three 1\ M. : nothing re- markable occurred previous to the expulsion of the foetus, ex- cept that there was a larger quantity of the liquor amnii dis- charged soon after the labour commenced than is usual ; the pains returned at irregular periods, from 15 to 30 minutes, for 36 hours, without producing any descent of the head: the pains thus became stronger, and returned at shorter intervals, so as to expel the head in three quarters of an hour; the shoulders and body followed soon fcy a itw more pains.
The pulsation had ceased in the funis, but soon returned; and the infant showed signs of life sufficient to encourage the hope of respiration being established, the whole surface of the body being changed from a livid to a florid hue.
The inspirations became more frequent, and were attend- ed with convulsive twitchings ; the motion of the heart was very evident, but there was not any puUe at the wrist distin- guishable ; the vital functions gradually diminished, and ceased in three hours after birth.
Introduction to Dispensary Rules and RcgaL'tR-iris.
Dissection^
492 Report of the City and Finshiry Dispensaries.
Dissection. — A small quantity of a yellowish fluid was found in each cavity of the thorax ; the mediastinum was attached only to the right side of the sternum ; the heart was placed on the right side, and no part of that organ reached beyond the middle of the sternum; the right lung very small, but divided into three lobes.
The left cavity of the thorax contained the small and part of the large intestines, which had protruded through an opening in the diaphragm of a sufficient size to admit of their being essily retracted ; the left lung was also very small, but divided into two lobes.
The cavities of the heart were natural ; the foramen ovale of its usual appearance ; the canalis arteriosus was large; the pulmonary vessels were small, particularly on the left side, corresponding to the diminished state of the lung.
The vessels from the curve of the aorta and intercostals were distributed as usual ; the phrenic, coelic, emulgcnt, spermatic, and umbilical vessels were natural ; the trunk of the superior mesenteric artery was continued through the opening of the diaphragm to supply the abdominal viscera that had protruded into the thorax ; the inferior mesenteric and the vessels going to the lower extremities were distri- buted in the usual manner.
The liver was large; the gall-bladder and vessels were perfect ; the spleen, pancreas and stomach were well formed ; the duodenum ascended in its course across the spine to the opening in the diaphragm ; the jejunum ilium, caecum, ascending and transverse colon, were situated in the thorax, where they appear to have been formed, as from the attachment of the mediastinum and size of the lung there could not have been any viscera to have occupied the. )eft cavity of the chest.
The descending colon passed through the same opening into the abqlomen over the left kidney, and formed the sig- moid flexion on the brim of the pelvis, and terminated in the rectum.
The superior part of the left kidney was opposed to the opening in the diaphragm, and could be seen from the tho- rax on raising the intestines.
The
Royal Society. 4$3
The child was much above the standard size, but the ex- ternal parts of the body were well formed.
Death ensued in consequence of the diminished capacity of the lungs, their organs not being of sufficient size to ad- mit air in quantity sufficient for the continuance of respira- tion.
The preparation, and drawings made from the same, are preserved in my museum, and may be seen by any person who is desirous. ,
John Taunton,
Greville street, Hatton Garden, Surgeon to the City and Tinsbury Dispen- May 18, 1809. saries, and City Truss Society, Lecturer
on Anatomy, Surgery, Physiology, &c.
LXX XVI 1 1 . Proceedings of Learned Societies,
ROYAL SOCIETY.
X he First Part of this Society's Transactions has just been published. The following are its contents :
1. The Croonian Lecture. On the Functions of the Heart and Arteries. By Thomas Young, M.D., For. Sec. R.S. — 2. An Account of some Experiments, performed with a View to ascertain the most advantageous Method of con- structing a Voltaic Apparatus, for the Purposes of Chemical Research. By John George Children, Esq., F.R.S. — 3. The Bakerian Lecture. An Account of some new analytical Re- searches on the Nature of certain Bodies, particularly the Alkalies, Phosphorus, Sulphur, Carbonaceous Matter, and the Acids hitherto undecompounded ; with some general Observations on Chemical Theory. By Humphry Davy, Esq., Sec. R.S., F.R.S. Ed. and M.R.I. A.— 4. An Account of a Method of dividing Astronomical and other Instruments, by ocular Inspection ; in which the usual Tools for graduating are not employed j the whole Operation being so contrived, that no Error can occur but what is chargeable to Vision, when assisted by the best optical Means of viewing and mea- suring minute Quantities. By Mr. Edward Troughton. Com- municated by the Astronomer Royal. — 5. A Letter on a Canal in the Medulla Spinalis of some Quadrupeds. In a
Letter
491 Royal Society.
Letter from Mr. William Sewell to Everdrd Home, Esq,, F.R.S. — G. A numerical Table of elective Attractions ; with Remarks on the Sequences of double Decompositions. By Thomas Young, M.D. For. Sec. R.S. — 7. Account of the Dissection of a Human Foetus, in which the Circulation of the Blood was carried on without a Heart. By Mr. B. C. Brodie. Communicated by Everard Home, Esq., F.R.S. — 8. On the Origin and Formation of Roots. In a Letter from T. A. Knight, Esq., F.R.S., to the Right Hon. Sir Joseph Banks, Bart., K. B. P.R.S.— 9. On the Nature of the inter- vertebral Substance in Fish and Quadrupeds. By Everard Home, Esq., F.R.S.
June I. — The president in the chair. The conclusion of Dr. Henry's paper on the decomposition of ammonia was read. The result of the author's present experiments led him to perceive some errors in those of his preceding paper, and to conclude that the oxygen which he had disengaged from ammonia by electrization was derived from other bodies, and not from the ammonia; consequently that am- monia should not yet be considered as an oxide.
Mr. Davy read some remarks on Dr. Henry's experi- ments, which tended to prove that the composition of fcw» monia cannot be ascertained till the nature of nitrogen is determined. Dr. H. thought the proportion of hydrogen in ammonia, as determined by Mr. Davy, rather low, and es- timated it at 72 hydrogen and 28 nitrogen, instead of 74 hydrogen and 26 nitrogen ; but Mr. D. having repeated his experiments, found them very nearly correct, and took 73 — 27 as the truth.
An ingenious paper by the Rev. Mr. Lax, professor of astronomy at Cambridge, was read, on the means of gra- duatmcf and correcting mathematical instruments. The au- thor uses Carey's semi- circle of a foot diameter, corrects it by microscopes and observations, and adjusts it so as to counteract the expansion and contraction by change-of tem- perature.
june Q. — Dr. Wollaston read a paper proving the identity of columbium and tantalium, the former discovered by Mr. Hatchett,, the latter by the Swedish chemist Ekeberg. Dr.
W. pro-
Roijal Society. 495
W. procured some grains of the original specimens from the British Museum, and from Mr. Hatchett ; and notwith- standing the smallness of the quantity, he succeeded in proving them to be radically the same metal.
Dr. Wollaston also read another ingenious paper discover- ing a method of constructing a gonyometer for measuring the angles of crystals by means of reflection, with micro- scopes, which enable the observer to ascertain accurately the angles of crystals, whether rough or smooth. Dr. W. applied this useful instrument, of which a drawing was ex- hibited, to crystals of carbonate of lime.
A mathematical paper by Mr. Ivory was laid before the Society.
June 1.5. — A paper by Sir James Earle was read, de ] scribing a stone in the bladder, which occupied its whole contents, and weighed 44 ounces.
The Society for improving animal chemistry furnished a paper by Mr. Brande, detailing the results of a series of ex- periments on animal mucus and albumen exposed to gal- vanic electricity.
A paper by Dr. Pearson, on expectorated matter, was read. It appears from the Doctor's experiments, that the different kinds of expectorated matter differ rather in the proportion of the ingredients than in kind. They all consist of albuminous matter, water, and the two principal ingredients are muriate of soda and potash neutralized by animal oxide, if not by a destructible acid, besides a small proportion of phosphate of lime, ammonia, carbonate of lime, and probably phos- phate of magnesia and siliceous earth. The Doctor an- nounces that potash neutralized by animal matter is con- tained in the blood, and in most or all of the secreted and ex- creted fluids, namely, in dropsical water, pus, both that se- creted without breach of surface as well as that of abscesses, and in the urine, See. He has not found ihe soda, as repre sented by former chemists, to impregnate the animal fluids ^ and this he seems to think might have been concluded a priori, because it is admitted on all hands, that almost every kind of vegetable food contains the potash united to some matter destructible by fire, which is not the case of soda ; 3 and
4y6 Royal Society.
and that it is as little likely the potash should be altered by di- gestion, as the muriate of soda itself so constantly taken with our Food, it is worthy of remark, that the potash is in much larger proportion in expectorated matter than in the serum of the blood; so much so, that expectorated matter when exsiccated commonly shows signs of deliquescence on ex- posure to the air.
June 22. — A letter from Mr. T. A. Knight was read, on the relative influence of the male and female on the size and character of the offspring. Contrary to the opinion of Lin- naeus, Mr. K. considers the female as influencing the size and character, but opposes Mr. Cline's opinion, that large females should be used for breeding ; because, although their legs will be longer in proportion to the size of the foe- tus, yet their bodies will want the due proportion of depth and thickness, and the animal will be less vigorous and powerful. Thus, for instance, foals of large mares and small horses have the chest thin and narrow, whereas the contrary is the case with those of small mares and large horses. Mules from large mares the author found unser- viceable from their want of proportion, and consequently want of strength.
The Society for improving animal chemistry furnished a paper by Mr. Home, on animal secretions. Mr. H. formed some plausible conjectures on the probable effects of electri- city in assisting the secretion of blood, serum, albumen, and the other animal fluids. He was induced to this opinion bv examining the electric eel, and the immense quantity of nerves which appear necessary to produce the electric power.
Some interesting additional observations by Messrs. Pepys and Allen were read, on the azote disengaged by respira- tion. The authors in all their experiments on this subject found that a considerable quantity of oxygen was lost in the process of respiration, and that azote was formed ; that an animal can breathe oxygen and hydrogen an hour without any incc nvenience, but that hydrogen alone occasions sleepi- ness. The term azote, they observe, is an indefinite name for all gas that is incombustible, irrespirable, and inab- •orbdble by water , but, from Professors Davy and Berze-
lius's
French National Institute. 497
lias's experiments, they conjecture that it is really of a me- tallic origin.
An additional account of M. De Luc's atmospherical electroscope" was read, and also some illustrations of his theory of meteorology, developing his opinions of the origin of repeated thunder-claps, clouds, hail, &c, and other me- teorological phsenomena. The author accounts for the rapid fall of the barometer previous to a thunder-storm, by sup- posing the existence of some unknown light fluid which as- cends in columns at such times. This supposed fluid in his opinion effects various other purposes of atmospherical phae- nomena.
The Society then adjourned during the long vacation till Thursday the 9th or November next.
FRENCH NATIONAL INSTITUTE.
Analysis of the Labours of the Class of Mathematical and Physical Sciences of the French Institute, for the Year 1S0J.
MATHEMATICAL DEPARTMENT*.
Astronomy.. — The French" astronomers, who are now in possession of excellent instruments and methods of singular perfection, have not allowed any opportunity to escape of practising upon these instruments and these methods all the amelioration which reflection aided by long practice can suggest. There were grounds for supposing, thai in the construction of telescopes all possible combinations had been exhausted. In fact, the great mirror is necessarily con- cave, in order to collect under one and the same point all the rays of light which it reflects ; but the second mirror may be concave, as in Gregory's telescope, plain as in New- ton's, or convex as in Cassegrain's ; in short, we may sup- press this second mirror as proposed by Lcmaire, and so happily accomplished by M. Herschel.
Instead of these four plans, all of which have their ad- vantages and disadvantages, M. Burckhardt has proposed to substitute a fifth, which should have in addition all the merit of facility and of convenience. His small mirror is plain like Newton's : instead of placing it obliquely to the
* Drawn Op by M. Delambre, Secretary.
Vol. 33. No. 134. June 180Q. I i focus
498 French National Institute.
focus of the great minor, z. e. towards the upper extremity of the tube, which renders it inconvenient to observe under many circumstances, particularly in large telescopes, he places it perpendicularly to the axis, and towards the half of its length. In this place the section of the reflected cone of light is a circle, the diameter of which is precisely the half of that of the great mirror : it will therefore intercept a fourth part of the direct rays ; but M. Burckhardt remedies this loss by giving a larger dimension to the first mirror. The retrenched cone assumes a reverse position : the rays, instead of uniting, as they would have done, beyond the plain mirror, are collected at an equal distance, but in front, and pass through an aperture made in the centre of the great mirror, in the space which, as we have seen, receives no direct ray, and which is consequently useless for assisting vision. The advantage of this construction consists in re- ducing the length of the telescope one half, which thereby becomes easier to manage, and less costly. If the diameter of the concave mirror is a little larger, the central part which should have a hole requires no trouble; it is sufficient that the speculum, the only useful part, should receive the cur- vature necessarv for the distinctness of the image; and when it was really a little difficult to render it very exact, we might make up for it, since we have only a single mirror to curve, and because the plain mirror, on account of its dimension being a little larger than in the Newtonian telescope, fur- nishes easier and more precise verifications. The observer should be placed at the lower part and behind the great mir- ror, as with Gregory's telescope, which is the most con- venient position for following a star continually changing its place. Finally, M. Burckhardt has calculated, by setting out froiTLthe measurements of Newton himself, that a tele- scope of eight metres in focal length, reduced in this way to the actual length of four metres, would have three times more light than a common telescope of four metres, and would have a very valuable advantage over the latter for micrometrical measurements, on account of the double di- stance of its focus.
Before putting his new idea into execution, M. Burck- hardt
INDEX.
5°5
Dividing instrument. Cavendish's, 408; Lax on, 494
Dollond's patent. Hist, of, 838
Doors. To "prevent from dragging on carpets, 448
Earth. On theories of the, 170
Earthquake in Perthshire, 91
Earths. Experim. on, to ascertain if v metals, 157
Eds. Curious fact respecting, 410 Eggs carbonised, 5
Electroscope, Deluc's, 497
Elmes's portable bridge, 10
Ether, apparatus for preparing, 302 Etna, eruption of, 501
Eider on refrangibility of light, 337 Farey on geology, 257 ; remarks on, 385, 452; in "reply to Earl Stan- hope on musical tones, 292 ; on the Thames-archway, 372,
Feathers, carbonised, 5
Fence. The invisible, 270
Fibres for micrometers. New, 383 Fishing of anchors. Ball's method, 348 Flint glass. Report on, 337
Floating bodies. Burney on, 174 ; Orr on, 249, 476 ; Barlow on, 300
Fluoric acid decomposed, 88
Fcetus, a singular one, 174
French National Institute, 497
Fruit. To preserve without sugar, 208 Fruit-trees. On training, 35
Galvanism. On decomposition by, 86,87 Garden on distilling peppermint, 167 Garthshore on dispensaries, 221
Gas-lights. On, 217,432
Geometrical proportion. On, 425
Geology, 102, 170, 194,312, 385,389, 442, 452 German on wine, and on vineyards, '77, M2, 227 GianVs causeway. On the, 104, 194,
257 Gin Ho on gold dust of Le Loire, 28 1 Glass, flint, report on, 337 ; pastes, 339 Gold dust in department of Le Loire,
281 Goniometer. Wollaston's, 495
Gongh's remarks on Berzelius's hy- grometer, and Dalton's theory, 178 Graham on commerce, 68 ; on i^y crusts, and on marine plants, 191 Grapes. On culture of, 32
Growing timber. To ascertain value of, 327, 350
Hair, carbonised, 6
Ilauy's Introduction to Mineralogy, ' 389, 459 Hauy on Andrews Theory of the Earth,
170 Heat, subterraneous. On, S20
Henry on ammonia, 494
Vol. 33. No. 134. June 1S09.
Herdman's idea of a dietetic dispen- sary, 221 Herschel on comet of 1807, 56; on coloured concentric rings exhibited by glasses in contact, 250 Home on a peculiar joint in the bask- ing-shark, 174, 250 HoiveiCsheto fence, 270. Hume's new method of detecting arsenic, 401 Hydraulic investigations, 123,182 Hudrogen. Davy's opinion respect- ing, 173
gas from pit-coal. A ppara-
tusfor,217; on, 4:j2, 439
Hydrophobia. On, 24
Hygrometer, Berzelius's, 39 ; remarks en Berzelius's, 177; Cough's, 178 Lou, analysis of ores of, 12; affinity of carbon for, 234,273
Jury masts, Bolton's, 346
Knight on training fruit-trees, 35 ; on, radicles and buds, 174; on breed- ing of animals, 496 Laplace's Mecanique Celeste, 264,
494 Laskey's list of Scottish testacea, 252 Lax on dividiug instruments, 494 Learned Societies, 88, 173, 250, 332, 408, 493 Lectures, 93, 175,335,413
Lehardy's telegraph, 843
Levinrre on Andre's Theory of tlia Earth, J70
Lime. On burning, 433
Lime fused with iron, 150
Linen cluth. New method of paint- ing, 151 Madder, Smyrna, introduced into cul- ture, 412 Manchester Philosophical Society, 41 1 Manure. On, 438 Marine animals, large, b.lely taken, 90, 92, 174,251,253, 334,408,411 Man at on geometrical proportion,
426 Masts, jury. Bolton's, 326
Mc'caiiujue Celeste. Laplace's, 264, 494 Medicine, 305
Meuorology, 05, 96, 176,255,336,416,
503 Micrometer. Improved, 383
Mineralogy. Hauy'a Introduction to. 389, 459 Mountains. On formation of, 385, 442, 452 Muriatic acid, compounds of, free from water, 89
Mushet on charcoal, 3, 116; experi- ments on earths to ascertain if me- tallic oxides, 157; on affinity of oxide* of carbon for iron, 234, 273 K k Nitrogen.
5©* INDEX.
Nitntgfn. Singular disappearance, and
formation of, by potassium and
ammonia, 173 ; Davy's opinion of,
173
ffltraut compound. Opinion on, 173
Or? on floating bodies, 249,476
Optica!, instruments, 290, 337, 383
an, native, found in Brazilian
piatina, 250
Patents, ' 93.174,253,414,502 Pearson on expectorated matter, 4!!5 Ptudulum roils On, 30
Peppermint. On distiiliiij, 167
Pcpys on respiration, 406
Pe.tTifac!v>v. A curious, 501
Phosphoiic add found in iron ores, 14 ph ■«■ horic ttlm: On, 302
Ph mpliorus. Davy on, 479
PiftvhT of Paris cash. To harden,
409 ; on burning, 433
, contains native
palladium, 250
Poor, interesting details respecting
the, 221
Patftih fused with iron, 160
Potassium. Exper. on, with ammonia,
173; action of, on ammonia, 480 Pressure of atmosphere, 4 i 7
Proportion. On, 426
Prmist on prussiates, 42
Pr iterates. On, 42
Pygmies. Race of, 333
Radicles produced from bark, n;>t
from alburnum, 174
Refrangibility of light. On, 337
Respiration, on, 496
Richardson's, R., method of raising
large stones out of the earth, 214 Richardson, W,, on basaltic rocks,
102, 194; observation* on, 257 Rrtcks. On struc ure of, 102,194
Royal Society, 83, 173, 250, 332, 408,
493 SatfrHngtons method of preserving
fruit, 208
Screw-wrench. Improved, 450
Sea snake, 90,251,411
Secretions, animal. Agency of electri- city on, 488 Silk; carbonised, 4 Societies. Learned, S8, 173,250,332,408
493 Society of Antiquaries , 333
Society of Arts, Sec. 409
Speer on atmospheric density and
pressure, 417
Stanhope (Earl), Farey 's reply to, 292 Steal i:es, analysis of, 136
Stones. Machine for raising out of
the earth, 21 4
Stonyhurst establishment, 412
Strontian fused with iron, 160
Sub terraneous heat. On, 320
Sugar. Charcoal of, 3
Sulphur. Davy on, 479
S'llohurct, a triple, 408
Sun fish, 92
Surgical cases, 490
contrivance for preventing doors from dragging, 448
Taunton on hydrophobia, 24; Dispen- sary report, 490 Tar. Analysis of, 136 Taylor (the Platonist), discoveries in mathematics, 92 Telegraph. Lehardy's, 843 Telescopes. Proposed improvements of, 290, 337 Test a ecu, Sro!ti<h, 252 Thames archway. On the, 372 Thermometer. Proposal to alter scale of, 166 Timber, Growing. On value of, 327,
350 Time-keepers. On pendulums of, 30; on finding the rates of, 402
Toad found at the depth of 57 fa-* thorns in the earth, 251
Trees, fruit. On training, 35
Troug.htou's dividing instrument, 90,
173 Valley s.On formation of, 385,442, 452 Vauquclin on steatites, 136
Vauxfutlins analysis of iron and scoriae, 12
Vegetable substances. On carbonising, 3,49, 116 Vines. On culture of, 32
Vineyards <J Champagne. On, 77, 142,
227
Waistell on value of growing timber,
327, 350
Water. Ponderable matter of, 173
Walker, Ezra, on pendulum rods, SO
Walker's scale for thermometer, 166
We-rnerian Society, 90, 251, 409
Whale caught in the Thames, 334
Williams on culture of grapes, 32
Wine, Champagne. On, 77, 142, 222
Wollaslon on Brazilian piatina, 250 ;
on agency of electricity on animal
secretions, 488; on columbiumand
tantalium,494 ;on goniometer, 4?5
Wool, caibonibed, 4; Merino, 241,
287 Wrench. Barlow's improved, 450
Yoia^s hydraulic investigations, 123,
182; tables of elective attraction,
173
END OF THE THIRTY-THIRD VOLUME.
Printed by Richard Taylor and Co., Snoe Lane, Loudon.
French National Institute. 499
liardt fairly discussed it. Several objections were started : — the result was, however, that the idea deserved a trial. M. Caroche undertook to make the plain mirror proposed by M. Burckhanlt, and to adapt it to a telescope the great mirror of' which was two metres in focal length, and the aperture about a sixth of its length.
The invention of Borda's circle, from its exactitude, light- ness, and moderate price, forms an interesting period in the progress of modern astronomy. The utility and con- venience of this instrument for geodesic operations is uni- versally acknowledged: it is admitted to be superior to-every thing for fundamental and delicate researches, in which the necessity is felt of multiplying angles in order to attain the utmost precision. Thus, in order to determine the altitude of the pole, the obliquity of the ecliptic, the equinoctial and solstitial points, the declinations of the most brilliant stars which are not too close iovthe zenith, and finally for refrac- tions, Borda's circle seems preferable to the largest mural, or entire circles which are not repeating. It is therefore doing a real service to extend to new objects the utility of so precise an instrument : we may also employ it in the de- termination of the hour by absolute altitudes either of the sun or stars. The astronomers Avho have recently measured the meridian of Dunkirk and Barcelona, have already de- rived the advantage of thereby regulating their pendu- lums; they have supposed that in the interval of four or six minutes, during which four or six observations may be made, the altitude increases uniformly in proportion to the interval of time ; and thus we may without any risk take a medium between four or six consecutive observations, and treat them, by taking a simple arithmetical method, as we" would treat a single observation. M. Delambre, in fact, as- certained that there was no sensible error when the obser- vations regularly succeeded each other; which is most com- monly the case. As the contrary, however, may sometimes happen also, he had sought for a method of correcting the small error of supposition and of these various methods ; he has only published one, which, however, he had never occasion to make use of. These methods may also be applied
1 i 2 to
500 Trench National Institute*
to the observation of the distances from a star to a terrestrial object for the determination of the azimuths. M. Burck- hardt has contrived a new one, which he discovered by twice differencing the formulae of the altitudes. The correction of the second differences is proportional to the square of the variation of the horary angle multiplied by a constant. This square may be taken in the table which M. Delambre has given ; and immediately we easily determine the correction, having precise results for the hour, notwithstanding the inequalities of motion in the altitude.
In the observations of a star before and after its passage to the meridian, in order to have the meridian height, we may suppose the declination constant when a star or even the sun is observed about the time of the solstices ; but to- wards the equinoxes in particular, we must take an account of the variation in declinations j and M. Delambre has also given on this head a formula of a convenient application to all the planets, and even to the moon. M. Burckhardt now gives another, still simpler, since it merely consists in adding to the mean altitude the motion in declination be- tween the mean instant and the passage to the meridian ; but this seems to require more rigorously an equal number of observations before and after the passage, as well as equa- lity among the corresponding horary angles.
The parallax of right ascension requires a second correc- tion when the moon is under observation ; M. Burckhardt reduces it into tables of an equally convenient construction and application; he is the first who examined this problem, by means of which Borda's circle will give the meridian al- titudes of the moon with the same precision as that of the stars, the declination of which has no sensible motion.
When a star is very distinct, like the sun and moon, it is easy to bring it into the object glass for each successive observation; but when it is a star, we experience greater difficulties : the use of the azimuth circle, intended for these inquiries, is tedious and inconvenient ; we may see in the meridian the various methods resorted to by M. Delam- bre. M. Burckhardt proposes a moveable arc of a circle, which he attaches to the azimuth circle with a screw, and
which
Eruption of Etna* — Petrified Tortoise. 501
which prevents the alidada from going from one extremity . of this arc to the other, without describing precisely an arc of 180 degrees. In this way the circle i3 in the vertical of the star; and in order to find it, we have only to give to the circle or to the object glass a vertical motion ; but this me- thod would still be insufficient if we had to observe a star by day light, for in this case we might pass far above it without perceiving it.
If the siar has a perceptible azimuth motion in order to bring it to the centre of the glass, we shall be under the ne- cessity of slackening the screw, in order to displace a little the subsidiary arc : this attention will neither be long nor troublesome.
This subsidiary arc requires a small change in the form of the alidada; but without in the least changing this form, a simple trace with the crayon upon the azimuth circle, or rather a small spring which should drop in order to allow the alidada to pass, and which should rise when it has passed, would be sufficient for bringing it either to the same posi- tion or to a different position of ISO degrees in azimuth.
[To be continued.]
LXXXIX. Intelligence and Miscellaneous Articles.
ERUPTION O* ETNA.
feiciLY, April 12, 1S09- — " Mount Etna burst out on the 26th or 27th ult. in a most tremendous manner. The first great eruption was from the very top. Twelve new craters opened shortly afterwards, about half way down the moun- tain, and have continued to throw out rivers of burning lava ever since. Several estates have been covered with the lava 30 or 40 feet deep. During the first three or four nights, it was seen very distinctly from this place, and a very large river of red hot lava running down from the crater."
PETRIFIED TORTOISE.
As some men were lately digging in Swanage rocks, on the island of Purbeck, a petrified land tortoise was discovered, seventy feet deep from the surface, in the highest state of
perfection j
502 List of Patents for New Inventions.
perfection ; the Rev. Samuel Woolmer being in the neigh- bourhood, the men brought it to him for his inspection, who being struck with admiration at so great a curiosity, immediately offered them five guineasfor it, which they de- clined accepting, but after exhibiting it about, sold it to a gentleman of Upvvay, for eight guineas; since which 300/. has been offered for it, but refused. It was supposed very probable that its mate might be found near, as the male and female are generally together: upon which further search was made ; when* after digging some time, another was dug up, but entirely broken in pieces and spoiled.
LIST OF PATENTS FOR NEW INVENTIONS.
To Thomas Noon, of Burton-upon-Trent, in the county^ of Stafford, for improvements on guns, pistols, and other similar fire-arms, which improvements are applicable to cannon and other large guns. — May 4, 1809.
To Nugent Booker, of Lime Hill, in the county of Dub- lin, for his new plan for improving and erecting lime-kilns, whereby a very considerable saving is made in fuel, and the lime most perfectly burnt in a short time, which he deno- minates Grellier and Booker's lime-kiln. — May 9.
To Bartholomew Folsch, of Oxford Street, in the county of Middlesex, merchant, for improvements on certain ma- chines, instruments, or pens, calculated to promote facility in writing. — May 9.
To William Johnson, of Blackheath, in. the county of Kent, gent., for his new or improved process for heating iiuids for the purposes of art and manufacture. — May 15.
To Edward Manley, of Uftculm, in the county of Devon, for a plough upon an entire new construction. — May 30.
To John Lindsay, (late lieut.-cql. of the 71st regiment,) of Grove House, Edgware, in the county of Middlesex, for a night and day telegraph. — May 30.
To Edward Cragg, of Hertford, in the county of Chester, carpenter, and William Cragg, of Old Ford, in the county of Middlesex, builders' agent, for certain new modes of im- provements in the making or preparing of salt. — June- 8.
To John Frederick Archbold, of Great Charlotte Street, in the county of Surrey, gent., for an improvement in the system of distillation, rectification, and brewing. — June 8.
To Thomas Wells, of Erdington, in the county of War- wick, cock-founder, for a method of making and construct- ing barrel cocks and water cocks. — June 8.
JpETBQRO-
THE
PHILOSOPHICAL MAGAZINE:
COMPREHENDING
THE VARIOUS BRANCHES OF SCIENCE,
THE LIBERAL AND FINE ARTS,
AGRICULTURE, MANUFACTURES,
AND
COMMERCE.
BY ALEXANDER TILLOCH,
M.R.I.A, F.S.A. Edin. and Perth, &c.
" Nee aranearum sane textus ideo melior quia ex se fila gignunt, nee noster vilior quia ex alienis \ibamus ut apes." Just. Lips, Monti. PoHt. lib. i. cap. i.
VOL. XXXIII.
For JANUARY, FEBRUARY, MARCH, APRIL, MAY, and JUNE, 1809.
LONDON:
FRINTED BY RICHARD TAYLOR AND CO., SHOE LANE:
And sold by Richardsons; Cadell and Da vies; Longman, Hcr$T|
Rees, and Orme; Vernor, Hood, and Sharpe; Murrat;
Highley; Sherwood and Co.; Harding; London;
Bell and Bradfute, and Constable and Co.
Edinburgh: Brasu and Reid, and Niven,
Glasgow: & Gilbert &HoDGEs,Dublin.
D ivs of the
Month.
May 27 28 29 30 31
June 1
3
4
5
6
7
8
9
10
U
12
13
14
15
16
17
18
1
20 21 . 22 23 24 25 26
Meteorology.
meteorological table,
By Mr. Carey, of the Strand,
For June 1809.
Thermometer.
503
•x ^
*■■
60°
62
60
50
50
54
5<2
50
55
53
52
52
53
49
50
52
59
6o
6i
58
56
57
55
56
62
63
64
66
66
56
69°
71
70
61
63
73
57
63
66
63
66
64
63
59
60
59
6])
69
68
66
68
69
67
66
76
73
69
76
74
65
65
o ^
— • .c
54°
53
52
5;)
55
50
47
55
55
51
52
51
51
50
52
55
56
54
55
54
55
52
54
56
62
63
64
62
60
49
50
Height of
the Bnrom.
Inches.
29*64 •65 •50 •89 •75 •42 •52 •99 •69 •34 '56 •79 -65 •59 '59 •86
30*10 •01
29'93 •90 '95 •78 •85 •91
30- 1 0 •26 •35 •31 •36 •45 •38
Weather
70
62
61
80
5]
85
46
80
51
47
48
62
32
30
33
47
56
61
58
81
85
62
59
82
91
85
59
78
96
71
75
Fair Pair
Showery Pair Fair Fair ' Stormy Pair
Showery Rain Showery Showery Rain Rain Showery Cloudy Fair Fair Fair Cloudy Fair Fair Faii- Fair Faii- Fair Cloudy Faii- Fair Fair Fair
N. B. The Barometer's height is taken atone o'clock.
£ 5°4 1
INDEX to VOL. XXXIII.
Achromatic pusses, on, 337
drill-Phosphoric, found in iron ore,
14 j prubsic, exper. on, 42; fluoric,
decomposition of, 88 ; muriatic,
combinations of, free from water,
89; prussous, discovered, 409
Acids. Davy on the hitherto unde-
composed, 479
Alkalis. Davy on, 4*" 9
Allen on respiration, 496
Ammonia. Action of potassium on,
173 Ammonia from pyrophorus, 89; use- ful in manure, 438 Analyses. Vegetable and animal matters, 3 ; iron, iron ores, and scorias, 12; prussic acid, 53; of potash, 89; of steatites, 136*; of Laplace's Mecanique Celeste, 471 Anchors. Improved, 348 Anderson's method of painting cloth,
151 Andre on the earth's surface, 170 Andre's geological theory, 312
Animal substances. On carbonising, 3,47, 116 Animal secretions. Agency of elec- tricity on, 488, 496 Antrim'. Basaltic surface of, 102, 194,
257 Arseniate of copper, native, 332
Arsenic. New method of detecting,
401 Astronomy. Hist, of, for 1807, 497 Atmosphere. Density and pressure of,
417 Bakerian lecture, Davy's, 479
Ball's improved anchor, 348
Banks (Sir J .) on Merino sheep, 241 ,
287
Baritium obtained by fusion, 1 62
Barloic's screw wrerio:, 450
Barlow on floating bodies, S00; reply
to, 476
Barometrical measurements. On, 97
Barytes- Curious Exper. on, 158, 160
Basalt. On, " 102, 1° . 257
Basking ihttrk, 92, 174, 408
Bengorc promontory. On the, 104,
194,257
B> lelius's pr< posed hygrometer, 39;
remarks on, 177
Bwi s analys.s of Mt'canique Celeste,
264 Blood. Charcoal of, 47
Bolton's jury masts, 346
Books new, 49$
Boullat on ether, 302
Bo'nnoits triple sulphuret, 408
Breu-sier on optical instruments, 290,
383 Brick-making. O.i, 433
B'idpe, portable, Mr. F.lme's, 10
ita^ produced from bark, not from alburnum, 174
Barney on floating hodies, 174
Carbon, oxidss of, their affinity for iron, 234, '273
. . Davy on, 479
Carl'o»ated hydrogen gas from pit-coal. Apparatus for, L'l 7 ; on, 432,439 Carbonisation. Exper. on, 3, 47, 116 Carey* s Meteorological Tables, 96, 1 TO, 256, 336,416, 503 Carr on geology, 385, 452 ; reply to,
442 Chaptal on vineyards and wine, 77, 142, 227 Chrojne found'in the iron ores of Bur- gundy, 13. Clegg's apparatus for carbonated hy- drogen gas, 217 Coalgas. On, 217,432,439 Coke. On its uses, 433 Col^uhoun on dispensaries, 221 Commerce. Graham on, ' 68 Comet of 1807. Observations on, 56 Cox on ammonia in manures, 438 Cuxipr on theories of the earth, 170 Daltons theory. Berzelius on, 39 Daruiiniana, 305. Danbuisson on subterranean heat, 320 Davis on coal gas, coke, lime-burning, &c, 433 Uary's theory, 86, 87; Bakerian lec- ture on the decomposition of fluoric acid, on the muriatic acid, 0€) ; pn ammonia from pyrophorus, 89 ; exper, on the action of potas- sium on ammonia, 173; alkalis, phosphorus, acids, &.c. 479, 494 Detucs electroscope, 497 Density of atmosphere, 417 Derby shire. Geology of, 257 Dcrry. Basaltic surface of, 102,194,
257 Dietetic dispensary proposed, 221
Discuses. Treatment of, 305
Dispensary reports, 49(!5
DistUlalion of animal and vegetable substances, per se, 3, 116; of pep- per mint; 16&. Dii iling
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A
Section.
- J\3E<Je.
ENGRAVINGS.
Vol. XXVII. is illustrated with a Quarto Plate of Mr. Stfevens's Com?
pound Gasometer Mr. Maseres's Fire- Escape Mr. Walker's new
Optical Instrument called the - \ascoftf — Mr. Snodcrass's Method
pt Heating Buildings and Apartments by Means of Steam — Mr. Trotter's Machinery for Curvilinear Sawing, and Mr. Hardie's Improve'! Book** lender's Cutting Press — Mr. George Field' 4^r Heating Rooms,
and i ;;, ing various Articles — figures, illustrating the Manner of using Mr. Walker's Transit Instrument — Dr. Wollastqn's Camera Lucida for drawing from Nature in Perspective.
Vol. XXVIII. is illustrated with Mr Kater's H — R tMsOEw'*
Optigraph improved by Mr. Jones-— Figures to illustrate Mr. Evans's Paper on Goniometry — Apparatus employed by Mr. Davy in his new Gal? vanic Experiments — -Dfscroizilles' Alkali-meter j and Figures to illus- trate C. A. Prieur's Experiments on the Decomposition of Light — A Qaiarto Tlate. containing a Skeleton of the Indian Elephant— An Octavo Plate on the same Subject — A Quarto Plate of Tables relating to Musical Temperature, by Mr. Farey — Anatomical Figures relating to the Elephant. Vol. XXIX. is embellished with a Portrait of the late Dr. L'arwjn; from an original Picture in the Possession, of Dr. Thornton — A New Mi- crometer, invented by Mr. Brewster — A Representation of the Comet now visible. — Mr. Field's Plan fir Building Towns and Villages com- posed of Circular Buildings — Mr. Pefys's New Eudiometer — A Quarto f'late of the Apparatus employed by Mess; Allen and Pei-ys in their Ex- periments on Carbonic Acid — A fourth Plate to illustrate M, Cuvier/S Paper on Elephants — Lieut. Ccl. Crichton's Bed tor the easy Conveyance of Sick and Wounded Soldiers : engraved by Portia — And Capt. Pas- lt.y's Improved Telegraph: engraved by PoRtRr.
Vol. XXX. Sir H. C. Engleiteld's Mountain barometer, engraved by Lgwry — A Plate to illustrate M. Cuvier's Paper on Elephants — Another Plate on the same Subject. — I and 2. Two Plates to illustrate M. CuVisr's Paper on Elephants* engraved by Porter. — 3. Figures to illustrate Mr. Herschel's Paper on Coloured Rings. — \ Skeleton of the American Mammoth, engraved by Porter. — A Portrait of M. Carrot — The Oil- mill of Bangalore.
Vol. XXXI. Mr. Davy's new Eudiometer. — Geological Sections of Strata, in Matlock, Derbyshire, by Mr. Whitehurst and Mr. Farey.— Illustration of the Chinese Method of propagating Fruit Trees by Abscis- sion— And Mr. RbQad's Gauge for measuring Timber, — illustration of Mrs. D'OyleY's Method of breeding Poultry ; Mr. DftEW'l Balance Level for laying-out Land for Irrigation} and an Experiment in Optics.— M'. £. Turkell's Construction of Chemical Muffles.— Mr, Gilpin's Machine for raising Coals and Ores. — Wilson's Secure Boat, or Life Boat ; and Boswell's improved Capstan : engraved by Porter. — Pepys's Apparatus for Decomposing the Alkalis under Naphtha: engraved by Ljwry. — Atkins's improved Hydrometer for weighing bolids and Fluids.
Vol. XXXII. Mr. CleaLI/s Machine for thrashing Hemp; and Mr. Bond's Machine for breaking Hemp. — Mr. Ward'* Compensation Pen- dulum.— Mr. GkoombriDge's Diagram of the Motion of the: Planet — A Portrait of Sir H. C. Enc-lifield. — Mr. Charles Le Caah's Tram-Piates — and Mr. Collier's Ship Stove.^- Apparatus employed by Messrs. Allen and Pepys in their Experiments on Respiration. — Mr. Henry's Apparatus for Decomposing Compound inflammable Gases. — Apparatus employed in the Royal Institution for the Decomposition of Potash by lion. — Bell's Method of s***-^ Shipwrecked Mariners.
Vol.
33,
Philosophical Magazine. January 1S0&
■cBtafe4£€^~.
CONTENTS of NUMBER CXXTX.
P^.ip
I. Result of so'ne Experiments on the Distillation of va- rious Vegetable and Animal Substances ib the dry Way. )AVID MtfSNET, Esq. -
^T Ii. Description or' a Portable Bridge, invented by Mr. | \mes Elmes, Architect, of College-Hill, Queen-Street, ,yCheapside, London - - - -
III. Analysis of some Iron Ores in Burgundy and Franche- Comte ; to which is added an Examination of the Pig Iron,
K Bar Iron, and Scoriae, produced from them. By M. Vau-
aUHLIN -
IV. On Hydrophobia j-
V. On Deal Pendulum Rods
VI. An Account of a Method of hastening the Maturation §*§J^of Grapes, \\y John Williams, Esq., in a I
Fit. Hon. Sir Joseph Banks, Bart. K.B. P.R.S.
Vn. On a new Method of training Fruit Trees. By Tho- as Andrew Knight, Esq., F.R.S., Szc.
VIII. Proposed Improvement of the Hygrometer. ^ I. Bebzelius V --'".• .4.
*&$} IX. Materials for a History of the Prussiatcs. By M. *f Phoust ----._
X. Observations of a Comet, made with a View to invest ^ pate its Magnitude, and the Nature of its Illumination
.TLLIAM HERSCHEL, L.L.D. F.R.S.
Letter to the
10
ri
24 3°
32 35
llated by M. Liiaftal. iiy. C ' XIII. Mr. Davy's Theory
AfiS vr,r x*. t^ ~,
ory
XIV. Mr. Davy's Theory
XV. Proceedings of Learned Societies
XVI. Intelligence and Misceil logical Table
"^~^>
5CI. On Commerce. Being a second Communication from f'SS Mr. Graham, in Answer to our Correspondent Lapis
XII. Memoir upon the Vineyards and Wines of Cham- pagne in France : Written in answer to certain Queries circu- lated by M. Ciiaftal. By. M. Gekmon, of Epernay
* Communications for this Work, addressed to the Editor, at \o. 1. Carey-street, Lincoln's Inn, will meet with every attention.
TAYLOR AtfD CO. PRINTERS, SHOE LANEf FLEET STREET,
EDUCATION7.
For the Use of Schools, and all those in the hip.her arjd middle Classes of Society, who are entering oh the Study of C
In the Press, and speedily will be published, i \Xh a great
Variety of very neat Copper-plate Engravings of Chemical Apparatus, in, pne Pocket Volume, Price 3s. 6d. bound,
THE RUDIMENTS OF CHEMISTRY,
WITH TAMIL1AR ILLUSTRATIONS AND E XPERJ M t.N TS,
By SAMUEL PARK;
Manufacturing Chemist, And Author of the Chemical Catechi 03" The new Edition of the Chemical Catechism is r-ov' on Sale, and may be had of all the principal Booksellers in the United Kingdom. This Book is designed, not only for the Use of the more advanced Students in. Chemistry, but will be found interesting to all those who are engaged in Agriculture, in the Practice of Medicine, or in any of the Manufactories cf* the Country; and is the only elementary Work tba iliuc-
trations of the late surprising and truly important Discoveries of Mr. Davy.
MR. DAVY'S IMPORTANT DISCOVERIES. This Day 5s published, the Fouith Editi >n, Price 9s. in Boards, of
PARKINSON'S CHEMICAL POCKET-BOOK: to which is an- nexed, An Account of the recent Discoveries of Mr. Davy, respecting the Chemical Agencies of Electricity ; the metallic Nature of the fixed Al- kalis, of Ammonia, and of the Earths; the Decomposition of Sulphur and of Phosphorus, as well as of the boracic and fluoric Acids, and even of Ni- trogen 3 and the extraordinary Experiments of the same Gentleman on the Muriatic Acid.
Printed for Sherwood, Neely, and [one? ; J. Murray; J. Highley, J, Ridg- way, J. Callow, E. Cox, and J. and J. Arch,
'*** Those who have already purchased the Fourth Edition may be supplied with the Account of Mr. Davy's Discoveries, Price is. to bind with the Pocket-Book.
The Albion Pre-s Edition*
Mr. IVardles Charges against His Royal Highness the Luke aj York, Commander in CI This Day is published, printed in 8vo., with a new and bold Type, illus- trated with a striking Portrait < f the Duke ol York, No. I. price only A CIRCUMSTANTIAL REPORT of the EVID1 CEi -.pen the Charges preferred against
the DUKE OF YORK, in the capacity of Commander in Chief, in the Month of February i8c.q ;
By G. L. WARDLE, P.
Before the Honourable House of Commons. " Unless corruption be attacked, and atta< . untry
will fall an easy prey to an inveterate enemy."
Mr War ,ecch.
This Work is published in Numbers, containing alternately thro four Half Sheets, embellished with Portraits of those Pen; >ns who have acted the most conspicuous Parts in the course of the Investigation ; and it will be delivered 10 the Public in rapid Succession as it proceeds. It handsome Volume for the Library, and when the Importan is considered, it is not too much to expect that it will be< Reference not only with Gentlemen of the Military Profes i< every well-wisher to the Interests of the Country. In No. 111. will be a tine Portrait of Mrs. Clarke.
Printed for James Cundee, Ivy-Lane,, Paternoster-row j an Fisher, and Dixon, Liverpool.
Vol. S3. ^ Philosophical Magazine. April 1809 (KM CONTENTS of NUMBEK :f.
1M XLV' 0b.5ervationson a late Taper by D.AVm. R,CHAKO. a|son, respecting the basaltic District in the North of Ireland, TOManrlon the Geological Facts them* deducible ; in Co-junction 3f with others observable in Derbyshire and other English Coun- HgtieB: with the Application of these Facts to the Explanation ^tf8 of some ot the most difficult Points in the Natural History of a the Globe, Bv Mr. John Fabky - - pa»e
i XL VI. Analysis of the M&anique Celeste of M. Ea Place Member of the French Institute, &c. By M. Bior - '
_.r?LVlL DescriP*ion of a new Fence made of tort elastic Wire, which becomes invisible at a comparatively short Distance, calculated for Pleasure-Grounds. By Henry | How ell, Esq.
XLVIII. On the Affinity existing between Oxides of Carbon and Iron. By David Ml'siiet, Esq
^ XLIX. On the native Gold Dust found in the Hills in the Environs ot the Commune of St. George, in the Department i of Ee Lone. By Mr. Giuno, Prefect of the Department of the Sesia - - „
^ L. Some Circumstances relative to Merino Sheep. By Sir Joseph Banks -
LI. Remarks on M. Burckh ardt's Contrivance for shortening Reflecting Telescopes 5 with a new Method of making Reflecting Telescopes with a Tube only one-third of the focal Length of the Object-glass. By David Brewster LL.D. F.R.S., and F.A.S., Edin. - . .'..
W^ }A\' A ^eP]y to Earl Stanhope, on his Defence of certain ^W Principles and. Facts erroneously stated in his Stereotyped ^li \Pril,c;|Ples ot'the Science of Tuning Instruments with fixed Jig Tones." By Mr. John Farey
LIII. On the Motion of floating Bodies in running Water. By Peter Barlow, Esq., of the Royal Military Academy^ Woolwich ----- 1
LIV. Memoir upon the Formation of the Phosphoric Ether by Means of a particular Apparatus. By M. Boullay, JJ Chemist, in Paris.— Read to the First Class of the National |S Institute the 23d of March, 1807
292
I/V. Memoirs of the late Era
smus Darwin. M.D.
LVI. Report on a Manuscript Work of M. Andre, ^formerly known under the Name of P. Chrysolog*?e db Gy,
,j w. ..„,. v """"u uiwu lmc ^rtllipoi JT. LHRYSOLOG^E DBVrY,
-entitled A Theory of the actual Surface of the Earth. By j MM; Bauy, Levierre, aniiCuviER. Read to the Class g|$
l$jJm<* Mathematical and Physical Sconces in the National Institute 312 fe|l
By J. F. Daubjissqn
. Method of ascertaining the Value of Growing Tim-
Bv Mr.
„.._ ^ ,.j o.^c*. u^tiii^o 111 uiC i-NallUUtii iilSUlllie
LVIL Observations upon Subterraneous Heat, made in the (Mines of Pouliaoucn, and of Buelgoat, in Britany, in France.
120 <?
: different and distant Periods of Time. ^Charles Wa'istell, of High Holborn ^ L1K. Proceedings of Learned Societies
LX. Jntetligence and Miscellaneous Article?— Meteoro
m
334-33-
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