« PreviousContinue »
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 fhall fee hereafter, that Mr Murdoch has reached the utmost point, either of economy in his procefs of distillation, or of fimplicity in the construction of his apparatus. The peculiar foftnefs and clearness of this light' (fays Mr Murdoch, under whofe direction the whole was completed), with its almost unvarying intensity, have brought it into great favour with the work-people: and its being free from the inconvenience refulting from the fparks, and frequent fnuffing of the candles, is a circumftance of material importance, a's tending to diminish the hazard of fire, to which cotton-mills are known to be much exposed. '
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 application 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.
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 perhaps 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 hun dred 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 1808.1
candles, oil and cotton for soldering used to cost him full 30l. 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 107. or 127., 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 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 friendsthe monopoly of a practice, which is already adopted by several persons who pretend to no secret or mystery in the art, We cannot 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 clear 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 a way. Winsor's analysis of Newcastle coal is certainly very complete. The gas flames he exhibits in the different apartments of
his house are extremely brilliant; and the variety and neatness of their application worthy of praise.
He deserves credit too, we think, for calling the public attention, more than had been done before, to the peculiar advantage of coke as a cheap and agreeable fuel. This substance is the residuum that is found after all the evaporable matter has been expelled from the coal by heat. It comes out from the distilling process in large spungy masses, greatly diminished in weight, but increased in bulk nearly one third. Though somewhat more difficult of ignition than coal, it burns longer, and gives out a steadier and more intense heat.
That it should do so, will not appear strange to our chemical readers, (and who is there now, that does not know something of chemistry?), when it is considered that the quantity of matter, which, in the combustion of coal, is changed from a solid to a state of elastic fluidity, must necessarily carry off much caloric in a latent state; while the glow of the coke radiates with an intensity unimpaired by any demand of this kind. The same respectable chemist we formerly mentioned, bears testimony to the superiority of coke. 'I have learned,' says Mr Accum, * that the heat produced by coke, when compared with that which can be obtained from coal, is at least as 3 to 2.' Thus he found, that it required three bushels of coal to distil a given quantity of water, and only two of coke. He tried the two substances also by combustion, with a certain measure of oxygen gas, by the fusion and the reduction of metals, &c.; and the same result was obtained, a result certainly not unimportant, since it proves that, by being forced to yield the material of a beautiful light, coal is actually improved very considerably in its power of giving heat. We have not the least doubt that this coke, as Winsor produces it, and as we have seen it used in his house, might be introduced to form, if not the whole, at least four fifths of our common fires, with a very great addition of comfort, cleanliness and economy. Let it be observed, however, that we possess no facts that warrant us in pushing this conclusion any further than regards the coke of Newcastle coal. Mr Murdoch, though he makes proper allowance for the coke produced in his process, does not enlarge at all on its qualities; and it is probable, that some species of coal generate coke too dull and difficult of ignition for consumption in our grates, and only fit to be used in stoves and furnaces where there is a strong draught. But we are persuaded, that the greater proportion of the other varieties in the island will be found, on trial, to yield the same sort of coke as Winsor's, and that it can never be produced in such quantity, by the extended use of
* Appendix to Report of the Committee, &c.
the gas lights hereafter, that the demand will not fully and rapidly absorb it. Its merits have long been acknowledged in many processes of art; and it is prepared from coal with the loss of all the volatile ingredients in the great manufacturing districts; and if the price were lowered, by turning the gas to account, it could hardly fail to become a favourite fuel.
We have taken no notice of the tar and alkaline liquor which are copiously produced in the distillation; because we have few facts to go upon in estimating their value. The former is useful as a coating to preserve, from the worm and rot, timber exposed to the air, or lying under water; and it is not unlikely, that other more important uses may be found for it. As to the liquor, we believe it to be of no use whatever; and it is one of the absurdities of Winsor's calculations, to reckon at one shilling per gallon, a substance, of which, we are convinced, no man in London would purchase a hogshead at the expense of warehouse-room.
When we said that the facts of Mr Winsor and his friends are less satisfactory than the others we recorded, we alluded to the circumstance, that, while he makes us stare at the unparalleled extravagance of his tables, where he gravely strikes a balance of annual profit to the nation at large, of one hundred and fifteen millions, and while, by a singular effort of moderation, he reduces the gains of his subscribers to the absolute certainty' of only 6007. a year for every 57. adventure,'-he cautiously avoids detailing minutely the expense of the apparatus, or taking, as an item on the debtor side, the interest of capital sunk, which, in Murdoch's statement, exceeds the annual expense, in the ratio of 11 to 1. We need not add, how much this must falsify all his conclusions, even if he had not disproved them himself by a deductio ad absurdum. The committee-composed, as their Report shows, of sensible, but not scientific men-do away half the va lue of their experiments, when, in a Memorial addressed to the King, they candidly subjoin to their account of them- Their present experience does not enable your Majesty's memorialists to calculate the expenses of the process, of management, of tubes, and pipes, &c. with any tolerable degree of precision. p. 19. The experiment in Pall Mall, therefore, proves as yet nothing more, than the possibility of lighting up a street with gas ;-a cue rious fact, without doubt; but we cannot call it a very important one, till we be enabled to add, that this can be done at a cheaper rate than with oil. It is not unlikely that it may and we strenuously advise the committee, while they have the command of money, instead of basking in the sunshine of delusive hopes, to institute another trial, in which all these expenses shall be rigidly