foot by this means the army was in security; for we were so closely encamped that we touched each other; and there were no void spaces.

p. 130.

The passage marked in italics is altogether wrong. In the original it runs thus: Et devez scavoir, qu'ils cognoissoient aucunement le train de nostre ost et armée. Car les batailles de nos gens par les compaignies quettoit chascun son soir l'unq aprez Paultre l'ost à cheval. Et les Sarrazins, qui cognoissoient ce train, entroient en l'ost aprez que le guet à cheval estoit passé, et fesoient secretement moult de maux et de meurtres. Which a careful translator might have thus rendered: For the troops, into which our corps of men at arms were divided, took it in succession, one after the other, to patrole round the army on horseback, &c. There is no great difficulty in this sentence of Joinville, though some Fittle grammatical incorrectness. But could Mr Johnes for a moment imagine that his own translation was right? In the Louvre edition, it is expressed plainly enough; and we will quote the words, as a specimen of the difference between that and the corrupted text. Et ceste persecution avenoit, pource que les batailles quietoient chascun à son soir l'ost à cheval; et quant les Sarrazins vouloient entrer en l'ost, ils attendoient tant que les frains des chevaus et des batailles estoient passés, si se metoient en l'ost par darieres les dos des chevaus, et r'issoient avant que jours feust.'

In many other places we have remarked great inaccuracy of translation. The layman, whenever he hears the Christian faith contemned, should defend it, not only by words, but with a sharp-edged sword. p. 102. This is quite contradictory to the sense of the passage, which, by the way, has been quoted oftener than any other in Joinville. The least attention to the context would have shown, that Louis, who is speaking, advises laymen to defend their faith with no other argument than that of hard blows. The French phrase, non pas seulement de paroles, though ambiguous, might have been properly rendered, not with mere words. But the best way of all would have been, to have looked at the Louvre edition, where he would have found that these words are an interpolation. In the story of Arthault de Rogent, p. 113. The poor knight was greatly surprized; n'estoit mie esbahi. P. 138. I and my knights returned thanks to God for *this second escape.' In the French: Et secondement grant grace nous fist nostre Seigneur, à mis chevaliers, et à moy.' p. 140. Epée is translated, first, spear, and afterwards sword, in two successive sentences, and in speaking of the same individual weapon. Prudent for preux, p. 160.; statesman, for homme d'etat, p. 168, are further specimens of Mr Johnes's negligence. How could

the

the last error fail to glare upon him, if he reads over his own translation, in which a young knight, like Joinville, is made to call himself a statesman? Homme d'etat means only man of rank in the Louvre edition it is riche omme; which has the

same sense.

Perhaps we may be thought to bear hard upon a gentleman, whose preference of literary recreations to those more usual among his class, does him unquestionable honour. But this honour, after all, is not immeasurable; and, whatever respect is due to a country squire who translates French chroniclers, we cannot, at once, give him a high place in the republic of letters. There is, in England, much more than a fair regard shown to gentlemen scholars; and, in Mr Johnes's instance, it would not be difficult to point out a great deal of ignorant or parasitical eulogy which has been bestowed upon his translations. That any translation of Joinville, which we have before us, or of Monstrelet, which is promised, or Philippe de Comines, if he should go so far, is demanded by the literay world, we firmly deny; and as decidedly assert, that Mr Johnes has done nothing, as yet, upon which a reputation of authorship can fairly be erected.

ART. XII. An Account of the Application of Gas from Coal to Economical Purposes. By W. Murdoch. Communicated to the Royal Society by Sir Joseph Banks.-Phil. Trans. for 1808.

Considerations on the Nature and Objects of the intended Light and Heat Company. London, Ridgway. 1808.

A National Light and Heat Company, &c. with four Tables of Calculations, &c. And various other Pamphlets. By F. A. Winsor.

THE

HE first in this list is a very interesting paper. It consists only of a few pages; but the facts it contains are curious; and it leads to the consideration of a subject, which has excited a good deal of attention in the metropolis, and is soon, it is said, to undergo a Parliamentary discussion. We have neither the power nor the wish to prejudge the cause; nor would we willingly hurt the feelings of any individual: our object is little more than a simple statement of facts. We have witnessed some obscure attempts to light with gas, that did not succeed; and we have read pamphlets on the subject, circulated perhaps to allure subscribers, which are as full of extravagance as they are void of

science. But, in spite of these failures, and amidst all the nonsense that has been published, and all the ridicule, in a great measure merited, that has been thrown on some of the projects, still we think there is discernible a basis of sound and practicable improvement, to the development of which a small portion of our time may be usefully devoted.

As the subject has been involved in much confusion, and, to many of our readers, must be altogether new, we shall first endeavour to state, in a brief and popular way, the chemical composition of coal, before we detail the new applications that are proposed to be made of its ingredients.

in

Pit-coal exists in this island in strata, which, as far as concerns the hundredth generation after us, may be pronounced inexhaustible; and is so admirably adapted, both for domestic purposes and the uses of the arts, that it is justly regarded as a most essential constituent of our national wealth. When exposed to heat, as we see it every day in our grates, it is manifestly composed of a fixed base of carbonaceous matter, and a variety of evaporable substances, which are driven off in the form of smoke and flame. But, instead of being consumed in this open way, the coal may be distilled, and these evaporable matters collected proper vessels, and examined. They are then found to contain, besides a considerable quantity of matter, which is condensed by cold into tar and alkaline liquor, an invisible elastic fluid, or gas, which no cold nor affusion of water can condense or absorb. It is a compound of two highly inflammable gases, which chemists call the light hydrocarbonate, and the heavy hydrocarbonate, or olefiant gas; and this mixture burns with a very brilliant and beautiful light. It is this gas which furnishes the flame in our common fires; but its beauty is there impaired by the un avoidable alloy of smoky vapour. A separation, however, may be effected by the distilling process, which leaves the pure aërial fluid such as we have described. All the new plans for lighting with coal-gas, proceed upon the principle of purifying this fluid, collecting it in reservoirs, and distributing it in tubes. From the furnace where the coal is distilled, a main pipe may convey all the evaporable matter into a large reservoir or gasometer, where,

by

* There are, in fact, according to Mr Davy, three inflammable gases given out in our fires ;-the two we have mentioned, and the gaseous oxide of carbon, which is known by its blue flame. They are all distinctly perceptible; the light hydrocarbonate forms the main body of the flame; the olefiant appears in brilliant jets; and the gaseous oxide is occasionally seen near the root of the flame, or in contact with the coal. It is possible that a small portion of this oxide may mix with prepared gas.

*

by various means-chiefly, we believe, by washing with water, it may be freed from impurities, and propagated through the tubes in every direction by its own elasticity. If nothing confine it, it will issue from the extremities in an equable flow, but still invisible, till a lighted taper be applied, when it bursts into flame, and continues to burn as long as the gas is supplied. Mr Accum found, by a comparison of shadows, in the manner suggested by Count Rumford, that the light of a gas flame is to that of an equal-sized flame of a candle or lamp as 3 to 1; or, in other words, that to light up a certain space, one gas-flame will give as much light as three candles burning with a flame of equal size. The products of the combustion are in both cases the same, water and carbonic acid gas; but with this material difference, that candles frequently, and lamps always, give out a quantity of smoke and soot; whereas the combustion of the gas is perfect, and leaves no sensible residuum,-nothing that can soil the most delicate white. Its effects on the air of a room are therefore less insalubrious than those of a candle, since the only noxious substance it yields is carbonic acid gas; and this it produces in smaller quantity than our common lights. From the inflammable properties of the gas, explosions, bursting of tubes, and other dangers might be apprehended. But there is no ground for such fears. On the contrary, nothing can be more simple or easy in the management. The gas may be confined by a stopcock with perfect safety, and issued as occasion requires. When it is exhausted, the flame goes out as quietly as the flame of a candle does, when the tallow is spent.

Such are the nature and properties of this curious and beauti ful fubftance, when examined in a fmall way in the laboratory of the chemist. But it frequently happens, that theories perfectly juit and elegant in themfelves, and confirmed by experiments on a finall feale, with a nice apparatus and fkilful management, are yet, when attempted in the large and wholefale way, utterly incapable of being reduced to practice; and thus, many a promifing plan has ended with performing nothing. But, in the cafe beH h 4 fore

* We should have suspected the proportion was overrated, had not the same accurate experimenters assured us, that 500 cubic inches of gas, burnt from the orifice of a jet, so as to produce a flame equal in size to that of an ordinary candle, consumed 1076 cubic inches of oxygene gas in the same time that a candle, kept burning in the best possible manner, consumed only 279; and we know, that the intensity of any artificial light depends on the rapidity with which oxygene is absorbed. '-See Appendix to Report of the Cora mittee, &c.

fore us, there are facts, of the defcription we want to be collected from different quarters, and furnished by individuals unconnected with each other, which fully verify the anticipations of theory, and the conclufions of more limited experiment.

The first, and by far the mott valuable of these facts, is contained in Mr Murdoch's paper; the chief object of which is to describe the mode of lighting the cotton-mill of Meffrs Philips & Lee, at Manchester. From this account we learn, that the whole of the rooms of this, the most extenfive cotton-mill in the kingdom, with the counting-house and store-room, and the adjacent dwellinghoufe of Mr Lee, are now, and have been for several years, lighted up with the gas from coal, to the exclufion of all other artificial light. The manner in which the gas is procured and dis tributed, we fhall quote in his own words.

The coal is distilled in large iron retorts, which, during the winter, are kept constantly at work, except during the intervals of charging and the gas, as it rises from them, is conveyed by iron pipes into large reservoirs or gasometers, where it is washed and purified, previous to its being conveyed through other pipes, called mains, to the mill. These mains branch off into a variety of ramifications, forming a length of several miles, and diminish in size as the quantity of gas to be passed through them becomes less. The burners, when the gas is consumed, are connected with the above mains by short tubes, each of which is furnished with a cock, to regulate the admission of gas to each burner, and to shut it totally off when requisite. This latter operation may likewise be instantaneously performed throughout the whole of the burners in each room, by turning a cock, with which each main is provided, near its entrance into the room.

By a comparison of fhadows, the whole light of the gas flames. ufed was found equal to that of 2500 candles of 6 to the lib. We cannot enter into all the items of expenfe: they are given with the moft fcrupulous accuracy; and the economical statement for one year ftands thus. The cost of the cannel coal which he ufed to furnish the gas, is 1251.; and of common coal to carbonize it, 201.; in all, 1451. ;-from which, deduct the value of the coke, 931., and the whole expenfe in coal is reduced to 521. The inte reft of capital funk in the apparatus, with a liberal allowance for tear and wear, is ftated at 55cl.; making the total expenfe of lighting the manufactory about 600l. a year. That of candles, to give the fame light, would be about 2000l. If the comparifon were made on the average of three hours a day, which, in moft cafes, would perhaps be nearer the truth, the advantage would be ftill more in favour of the gas lights. The intereft of capital and

Vide Nicholson's Philosophical Journal for October last.

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