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Haddon, Priuter, Castle Street, London.

THE

LONDON ENCYCLOPÆDIA,

OR

UNIVERSAL DICTIONARY

OF

SCIENCE, ART, LITERATURE, AND PRACTICAL MECHANICS,

COMPRISING A

POPULAR VIEW OF THE PRESENT STATE OF KNOWLEDGE.

ILLUSTRATED BY

NUMEROUS ENGRAVINGS, A GENERAL ATLAS,

AND APPROPRIATE DIAGRAMS.

Sie oportet ad librum, presertim miscellanei generis, legendum accedere lectorem, nt solet ad conviviam conviva
eirilis. Coonivator annititur omnibus satisfacere: et tamen si quid apponitur, quod hujus aut illius palato non
respondeat, et hic et ille arbane dissimulant, et alia fercula probant, ne quid coutristen, coprivatorem.

Erasmus
A reader should sit down to a book, especially of the miscellaneous kind, as a rell-behaved visitor does to a ban-
quet. The master of the feast exerts himself to satisfy his guests ; but if, after all his care and pains, something should
appear on the table that does not suit this or that person's taste, they politely pass it over without notice, and commend
other dishes, that ebey may not distress a kind host.

Translation.

BY THE ORIGINAL EDITOR OF THE ENCYCLOPÆDIA METROPOLITANA,

ASSISTED BY EMINENT PROFESSIONAL AND OTHER GENTLEMEN.

IN TWENTY-TWO VOLUMES.

VOL. X.

LONDON:

PRINTED FOR THOMAS TEGG, 73, CHEAPSIDE;

SOLD BY N. HAILES, PICCADILLY; E. WILSON, ROYAL EXCHANGE ; J. MASON, CITY ROAD

BOWDERY & KERBY, OXFORD STREET :
GRIFFIN & co. GLASGOW : J. CUMMING, DUBLIN: M. BAUDRY, PARIS: F. FLEISCHER, LEIPSIC:
AND WHIPPLE & LAWRENCE, SALEM, NORTH AMERICA.

1829.

5

11 - 7-52

THE

LONDON ENCYCLOPÆDIA.

"-//-SRMFA

G A S.

GAS. Goth. and Swed. gæsa, to ferment, a gently the bladder near the flame of a candle till term first commonly used by Van Helniont for it once took fire, it would then continue flaming fluids of an aëriform character.

till all the spirit was compressed out of the Gas. The various gaseous bodies have been bladder, which was the more surprising, because enumerated, and their properties explained, in that no one could discern any difference in the apdepartment of chemistry, to which they peculiarly pearance between these bladders, and those belong; and we now propose to direct the atten- which are filled with common air. tion of our readers to one of the most important • But then I found that this spirit must be practical applications of gaseous chemistry, in kept in good thick bladders, as in those of an ox, the illumination of buildings, and even large or the like; for if I filled calves' bladders therecities, by carbureled hydrogen gas.

with, it would lose its inflammability in twentyThe producing from coal an aëriform fuit, four hours, though the bladders became not rewhich could be distributed at pleasure in every laxed at all.' direction, for the purpose of economical illumi But the application of the gas thus generated nation, has justly been ranked amongst the great- to the purposes of economical illumination is est benefits which the science and enterprise of of much more recent date, and the merit of this country have conferred on mankind. introducing it is principally due to Mr. Mur

That coal evolves a permanently elastic and doch, whose observations upon the subject are inflammable aëriform fluid, seems first to have published in the Philosophical Transactions for been experimentally ascertained by the Rev. Dı. 1808. He first tried it in Cornwall, in the year Clayton, and a brief account of his discovery is 1792; and afterwards, in 1798, established an published in the Philosophical Transactions foi apparatus upon a more extended scale at Boulthe year 1739. The following is an extract from ton and Watt's foundry at Birmingham; and it his paper :- I got some coal, and distilled it was there that the first public display of gas in a retort in an open fire. At first there came lights was made in 1802, upon the occasion of over only pblegm, afterwards a black oil, and the rejoicings for peace. These, however, were then likewise a spirit arose, which I could no but imperfect trials, when compared with that ways condense; but it forced my lute or broke made in 1805 at Messrs. Phillips and Lee's cotmy glasses. Once when it had forced my lute, ton mills at Manchester; and upon the results of coming close thereto, in order to try to repair it, I which, all subsequent procedures, with regard observed that the spirit which issued from it caught to gas lighting, may be said to be founded. The fire at the flame of the candle, and continued burn- whole cotton mill, and many adjacent building with violence, as it issued out in a stream, ings, were illuminated with coal gas, to the exwhich I blew out and lighted again alternately for clusion of lamps, candles, and other sources of several times. I then had a mind to try if I artificial light. Nearly 1000 burners of different could save any of this spirit, in order to which, forms were employed; and the light produced I took a turbinated receiver, and putting a can was estimated equal to that of 2500 well dle to the pipe of the receiver, whilst the spirit managed candles of six to the pound. arose, I observed that it catched Aame, and The most important and curious part of Mr. continued burning at the end of the pipe, though Murdoch's statement relates to the cost of the you could not discern what fed the fame. I two modes of lighting (namely, by gas and then blew it out, and lighted it again several candles) per annum. The cost of the coal, used times; after which I fixed a bladder, squeezed to furnish the gas, amounting annually to 110 and void of air, to the pipe of the receiver. tons, was £125. Forty tons of coals to heat the The oil and phlegm descended into the receiver, retort £20, and the interest of capital sunk, hut the spirit, still ascending, blew up the blad- with due allowance for accidents and repairs, Jer. I then filled a good many bladders there- £550. From the joint amount of these items with, and might have filled an inconceivable must be deducted the value of seventy tons of number more, for the spirit continued to rise for coke, at 1s. 4d. per cwt., amounting to £93, several hours, and filled the bladders almost as which reduces the total annual expense to £602; fast as a man could have blown them with his wbile that of candles to give the same light mouth; and yet the quantity of coals distilled would amount to £2000. was inconsiderable.

Such was the flattering result of the first trial • I kept this spirit in the bladders a consider- of gas illumination upon a tolerably extensive able time, and endeavoured several ways to scale. In regard to its efficacy, we are informed condense it

, but in vain. And when I Þad a hy Mr. Murdoch, that the peculiar softness and mind to divert strangers or friends, I have fre- clearness of the light, with its almost unvarying quently taken one of these bladders, and prick- intensity, brought it into great favor with the ing a hole therein with a pin, and compressing work people ; and its being free from the incon. Vol. X-Part I.

B

.

venience of sparks, and the frequent necessity of The specific gravity of the former gas, that of air snuffing, are circumstances of material import- being = 1000, was = 560, and of the latter = ance, as tending to diminish the hazard from fire, 555: the fitness of gases for the purposes of illuto which cotton mills are so much exposed. minating is, generally speaking, directly as their

When Mr. Lee was examined by Mr. specific gravity. Brougham, in 1809, before a committee of the These experiments lead to the conclusion, that house of commons, against the Gas-light and a chaldron of good Wallsend Newcastle coals Coke Company's bill, his evidence was then would afford from 17,000 to 20,000 cubical feet equally favorable. He said, it gave no disagree- of gas, but the process of distillation, as now able smell; and when questioned as to the carried on in the large establishments for lightgoodness and purity of the light, ' I burn it,' ing the metropolis, seldom affords a larger aversaid he, every night in my own house, in- age produce than 12,000 cubical feet. There stead of thirty pairs of candles. He further can, however, be little doubt that, by improveadded, that he found it perfectly wholesome, ments in the construction and management of and that it was never complained of either in the retorts, the highest of the above averages his own dwelling-house, or in the mill.

might be procured; and calculatmg upon this The president and council of the Royal So- produce of gas, and upon the other substances ciety proved the high opinion which they enter yielded by the operation, we obtain a curious tained of the value and importance of Mr. and striking result. Murdoch's communication, on the employment The average value in London of a chaldron of of the gas from coal for the purpose of illumi- the best Newcastle coals is £3. The value of nation, by adjudging to him count Rumford's the products of its distillation is as follows: gold and silver medals.

£. $. d. We are indebted to Dr. Henry, of Manchester, for some valuable researches concerning the 12 gallons of tar, at 10d. .

14 chaldron of coke, at 31s.

1 18 9

0 10 0 composition of the aëriform products of several varieties of coal. He has pointed out the vari- 18 gallons of ammoniacal liquor, at 6d. Ở go ous, composition of the gas at different periods 20,000 cubic feet of gas, at 15s. per

1000 cubic feet

15 0 0 of the distillation, and has shown the important influence of the circumstances under which the

£17.17 9 coal is distilled, upon the proportion of gas yielded, and its fitness for the purposes of illumination. This fact attracted the notice of Mr. From the value of products must, of course, Clegg, the engineer of the Gas-light Company, be deducted, the value of the common coal emwho has founded upon it several ingenious im- ployed in the furnaces for heating the retorts, provements in the construction of the retorts amounting to about five chaldrons for every fiveemployed at the Westminster gas works. Coal and-twenty chaldrons submitted to distillation, in large heaps, and gradually heated, affords and the expense incurred by wear and tear, with less gas, and more water and tar, than when it is the wages of the laborers, and lastly, the inteextended over a considerable surface, and sud- rest upon capital. Mr. Murdoch's estimate, denly brought to a red heat. It is also very already quoted, will be found pretty accurate advantageous to dry the coal before its introduc- upon these heads. tion into the retort.

The tar is frequently employed for the proIn a small gas apparatus, erected in the labo duction of gas, either by mixing it with small ratory of the Royal Institution, it was found coal in the retorts, or by passing it through a that 4 lbs. of good Newcastle coal, introduced red hot tube. Every pound yields between seinto the retort previously heated red in a shallow venteen and eighteen cubic feet, containing from iron pan, may be made to afford a produce of fifteen to twenty per cent. of olefiant gas. When, from twenty to twenty-six cubic feet of gas, con- therefore, it has been cleansed by lime, it burns sisting of

with a very brilliant Aame, and is a most im8 Olefiant gas.

proving addition to the common gas. Wigan 72 Carbureted hydrogen.

and Cannel coal yield the best and largest pro13 Carbonic oxide and hydrogen. portion of gas for the purposes of illumination, 4 Carbonic acid.

but it is seldom it can be employed on account 3 Sulphureted hydrogen.

of its bigh price.

The burners, or tubes whence the gas issues 100

for combustion, may be infinitely and tastefully The carbonic acid and sulphureted hydrogen are varied. The varieties commonly employed are separated by the lime in the purifiers.

the bat's-wing burner, and the Argand burner. The same quantity of coal introduced into the The former consists of a brass tube having a slit cold retort, and gradually heated, afforded only at its extremity about a quarter of an inch long twenty-two cubic feet of gas, consisting of and one-fortieth of an inch wide. The latter is 5 Olefiant gas.

composed of two concentric brass tubes, about 70 Carbureted hydrogen.

two inches long, closed at bottom by a ring of 18 Carbonic oxide and hydrogen. brass, and at the top by one of steel, perforated 6 Carbonic acid.

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with sixteen or eighteen holes, of one-thirtieth of 1 Sulphureted hydrogen.

an inch in diameter. The gas enters the cavity

between the tubes, and issues from the circular 100

row of apertures, where it is inflamed, and hav.

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