7: * 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 o ther 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 cock 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. 9 Such are the nature and properties of this curious and beauti ful substance, when examined in a fmall way in the laboratory of the chemist. But it frequently happens, that theories perfectly just and elegant in themfelves, and confirmed by experiments on a fmall scale, with a nice apparatus and skilful management, are yet, when attempted in the large and wholesale 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 6 * 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 Com mittee, &c. าก fore us, there are facts, of the description 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 most valuable of these facts, is contained in Mr Murdoch's paper; the chief object of which is to defcribe 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 feveral 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 dif tributed, we fhall quote in his own words. • The coal is distilled in large iron retorts, which, during the win ter, 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 pu rified, 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 comparifon 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 expense: they are given with the most scrupulous accuracy; and the economical statement for one year ftands thus. The coft of the cannel coal which he used 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 comparison 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, tear tear and wear, remaining nearly the fame as in the former cafe, the whole coft would not exceed 650l., while that of the tallow would be 3000l. Here, then, we have a faving of three parts in four; and it is not likely, as we shall fee hereafter, that Mr Murdoch has reached the utmost point, either of economy in his procefs of diftillation, or of fimplicity in the conftruction of his apparatus. The peculiar foftnefs and clearnefs of this light' (tays Mr Murdoch, under whofe direction the whole was completed), with its almoft unvarying intensity, have brought it into great favour with the work-people: and its being free from the incon⚫venience refulting from the fparks, and frequent fouffing of the candles, is a circumftance of material importance, as tending to 'diminish the hazard of fire, to which cotton-mills are known to · be much expofed. ' The next fact we shall bring forward is important, in as much as it shows, that the superiority of gas-lights is not confined to great manufactories, but is equally apparent in those on a small scale, thus opening a much wider range for the possible appli cation of the new mode. We are indebted for this fact to a Mr Cook, a manufacturer of metal toys at Birmingham ;-a clearheaded, practical man, not apt to be dazzled by a fanciful theory, but governed in his transactions by a simple balance of profit and loss. There is a naïveté in his own account of his will amuse as well as instruct the reader. * process, which My apparatus is simply a small cast-iron pot, of about eight gallons, with a cast-iron cover, which I lute to it with sand, Into this pot I put my coal. I pass the gas through water into the gasometer or reservoir, which holds about 400 gallons; and, by means of old gun-barrels, convey it all round my shops. Now, from twenty or twenty-five pounds of coal, I make per haps six hundred gallons of gas; for, when my reservoir is full, we are forced to burn away the overplus in waste, unless we have work to use it as it is made: But, in general, we go on making and using it, so that I cannot tell to fifty or a hundred gallons; and, in fact, a great deal depends on the coal, some coals making much more than others. These twenty-five pounds of coal put into the retort, and say twenty-five pounds more to heat the retort, which is more than it does take one time with another, but I am willing to say the utmost, are worth fourpence per day. From this fourpence we burn eighteen or twenty lights during the winter season. In this manner are the candles which he used to employ, and which cost him three shillings a day, entirely superseded. But, besides his expense in * Philosophical Journal for December 1808. candles, 6 candles, oil and cotton for soldering used to cost him full 307. a year; which is entirely saved, as he now does all this soldering by the gas flame only. For in all trades in which the blow-pipe is used with oil and cotton, the gas flame will be found much superior, both as to quickness and neatness in the work: the flame is sharper, and is constantly ready for use; while, with oil and cotton, the workman is always forced to wait for his lamp getting up; that is, till it is sufficiently on fire to do his work. Thus, a great quantity of oil is always burned away useless; but, with the gas, the moment the stop-cock is turned, the lamp is ready, and not a moment is lost.' We must refer to Mr Cook's letter, for the details of expense, which he gives with faithful minuteness, and always leaning to the side unfavourable to the gas. The result of the whole is, that he saves 30%. out of the 50. which his lights formerly cost him: and, when we consider that his calculation allows the gas lights to be burnt the whole year, and the candles only twenty weeks, there can be little doubt, that the savings in this case follow nearly the same proportion as in the former. If the apparatus be erected on a still smaller scale, the saving,' Mr Cook assures us, ' will be • equally great :-for the poor man who lights only six candles, or uses one lamp, if the apparatus is put up in the cheapest way, will find it only cost him 10 or 12., which he will nearly, if not quite, save the first year. , The last trial of gas lights we shall mention, though not the most satisfactory, has made the greatest noise in the world, and was, indeed, what first led us to think upon the subject. During one of those excursions to the metropolis, with which we occasionally treat ourselves after a long period of northern rustication, our attention, at such a time alive to every thing, was arrested by a new and singular spectacle. The whole range of Pall Mall, from St James's to Cockspur-Street, was lighted up by means of lamps, fed with gas instead of cotton and oil, and certainly in a style of much superior brilliancy. We found, upon inquiry, that the conductor of this remarkable illumination was a Mr Winsor, acting under the auspices of a committee of subscribers; and that it was executed by them as a grand experiment to convince Parliament and the public of the national importance of their intended Light and Heat Company. Subscriptions had been collected, to a very large amount, to carry into effect Winsor's discovery; and 20,000/. vested in a committee, to assist him in his experiments, and make application to Parliament for a charter of incorporation. In prosecution of these objects, we afterwards learned, that a correspondence was opened with the Chancellor of the Exchequer in the month of March last; but he, alleging partly partly the advanced state of the session, which did not allow. a private bill to be presented, and partly his own doubts as to the utility of its object, declined promising his support to the measure. Since that time, a general meeting, it seems, has resolved not to regard the answer of Mr Perceval as a final rejection, but to come forward with their claims for a charter, during the present session. On what grounds these claims are founded, it is not very easy to discover. It is possible that government, foreseeing that the new mode of lighting would render less productive the taxes raised on the common materials, might think it wise to sanction some public establishment, by way of securing to itself a share in the profits. But it is the title of Mr Winsor and his friends to an exclusive privilege, that puzzles us. We attempted to look for it in his pamphlets; but encountered, at every step, such ignorance, quackery, extravagance, and false calculation, that we had scarcely patience to wade through them. As, however, we are in search of facts, we shall, in mercy to a foreigner and an enthusiast, who talks about his new light with all the fervour of a fanatic, pass over his wild reasonings in bad English, and state briefly whatever there is of value in his plans and processes. We must premise, however, that we cannot allow him the credit of being a great discoverer,-a name which he is suspiciously fond of arrogating to himself. That coal yields an inflammable gas has been long known; and its nature is particularly described by Dr Clayton in the Philosophical Transactions for 1735. With regard to the useful application of it, Mr Murdoch was undoubtedly the first who conceived the idea of conveying it through tubes, and employing it for artificial light; and we embrace, with pleasure, this opportunity of doing justice to the modest fame of our countryman. This was as early as the year 1792, long prior to the period from which Winsor himself dates his discovery. We fear, therefore, that the bugbear of his patent right, which he holds out in terrorem, will a vail him little, and that it is impossible to give him or his friends the monopoly of a practice, which is already adopted by several persons who pretend to no secret or mystery in the art. We cane not discover that there is any decided superiority in Mr Winsor's gas lights over those of Mr Murdoch. It is asserted, indeed, in Considerations,' &c. that it is necessary to take to pieces, now and then, the tubes in Mr Lee's manufactory, to clears them from impurities; while those of Mr Winsor contract no soil by any length of use. But Mr Murdoch expressly assures us, in his paper, that all inconveniences of this kind are now entirely done away. Winsor's analysis of Newcastle coal is certainly very come plete. The gas flames he exhibits in the different apartments of his |