public business of this nature, but to mercantile transactions only, I resolved to instruct, some persons to read my public lectures, and make my experiments: thus sending for Mr. H. he appeared in the most distressing situation. First I took him to an eating-house, and afterwards to my lodgings to clothe him. On inquiring at Messrs. Lardner and Co.'s, chemists, in Piccadilly, where he had been an occasional assistant, I could not learn any thing satisfactory, but determined to engage the man on trial for three months at a guinea per week, and to take his writing for £500 penalty, not to divulge or practise any of my means.

Having been near six weeks in my service, Mr. H. one lecture night did not attend his duty, when the large theatre happened to be quite crowded. I was thrown into the most unpleasant situation; for he had my manuscript lecture in his pocket; of course I was under the necessity of sending home a number of disappointed persons, after making them wait for an hour and a half. Scarcely had the audience been dismissed, when Mr. H. arrived, and very pertly told me he had been dining with a party of friends, which I did not think a sufficient excuse to disappoint the public and disgrace myself. In short, Mr. H. seemed so elevated in his spirit, and so free in his language, that I discharged him on the spot, with the loss of my manuscript, which he pretended to have mislaid.

Soon after, I received warnings from several gentlemen against Humphries, the smith, who had always monies on account, and never would let me have his bill; this man instead of attending to his business and orders, loitered away part of his time at the Lyceum, so much so, that my own servant has threatened sometimes to turn him out. He

had several tickets to bring in his friends, and begged permission to attend my experiments. But when I was cautioned that this man would make me an enormous bill, I refused him farther monies on account until he delivered a regular bill. At last he sent a lawyer with a long bill for £80, for tubes that were not worth 80s., because none of them were air-tight, so that he was continually repairing or making fresh ones.

Mr. Heard went travelling in the country towns, to read my own lectures, and make my experiments, for one shilling. A friend sent me one of his hand-bills from Bristol, which were printed in the same words as mine, with the same motto of Horace's, Ex fumo dare lucem.

So unknown and surprising is my discovery, even at this time, that the many scientific men who never saw my experiments, can hardly be brought to believe my assertions.

Mr. Nicholson, himself, who acts as the herald and champion for the antiquity of gas-lights, is still such a sceptic to my discovery, that he and his learned correspondents call my beneficial plan for their general introtroduction, "Gaseous Proposals for enlightening the Inhabitants of London." I make no doubt but it will soon be proved to the enlightened public, that my lights will put Mr. Nicholson's bright opinion into a total and everlasting eclipse, from which all the merits of his Journal will never clear him.

My subscribers find my Gascous proposals founded on the most solid basis, viz. that of constant, extensive practice; whilst the Gaseous crackers of the Philosophical Journal, seem only founded on envy or ignorance.

N

(D.)

ABSTRACT OF THE MINUTES OF EVIDENCE GIVEN TO A COMMITTEE OF THE HOUSE OF COMMONS ON THE FIRST APPLICATION OF THE CHARTERED GAS-LIGHT AND COKE COMPANY, FOR AN ACT OF PARLIAMENT TO INCORPORATE THEM, IN 1809.

prove.

how

From the

The following evidence of Mr. Accum* will little he knew of Gas-lighting at the period. detail which he gave of the plan, it appears that the gas was to be generated as it was wanted at different stations in each parish or district; and neither he nor Mr. Winsor seems to have had any ideas of making the gas and collecting and preserving it in gasometers, as was then practised at Soho and Manchester, according to the evidence of Messrs. Lee and Watt. This evidence is also curious, inasmuch as it contains a description of the first apparatus erected by Messrs. Boulton, Watt, and Co., for Messrs. Phillips and Lee, of Manchester.

The Committee met on the 5th of May, 1809. Sir James Hall was Chairman; Messrs. Warren and Harrison were Counsel for the Company, and Mr. Brougham for Mr. Murdoch. Mr. Accum was the first person examined by Mr. Harrison, and he stated that "for some time he had been engaged in assisting the Committee of the Company in experiments on the decomposition of coal, and that the coal was submitted in close vessels to the action of the

The parts marked with inverted commas are literally copied from the printed evidence.

heat of ignition, and by that process the products were obtained. The products were inflammable gas, tar, pitch, essential oil, and an ammoniacal liquor; and in the distillatory vessel remained behind the well known substance, coke; that one chaldron of coal will produce one and threequarters of coke by measure." He continued, "With regard to the coke produced in one of Mr. Winsor's stoves, I have compared it with other combustible matters usually employed; I have compared it with coal, and from those experiments I have reason to state that the quantity of heat given by a given quantity of coke, if you compare them weight for weight, is as three to one, provided the coke has been well prepared; but this must depend greatly upon. the nature of the coke produced: if the coke have been well prepared, the proportion I found usually was as three to two. The stove made by Mr. Winsor is so constructed as to prepare coke superior to that kind of coke which I have hitherto been able to procure in the market. Its relative power of producing heat by bulk must depend upon the shape of the coke; if large quantities are given in the form of a cylinder, it must make a material difference than if given in the form of a globe or other shapes; I could certainly say that coke is as three to two, by experiments I have frequently made. It would require three bushels of coal to produce the same quantity of heat as is produced by two bushels of coke. To ascertain that fact, I have taken a measured quantity of water, and I have applied heat to that water by means of coke, until all the water was evaporated. In this way I learnt the quantity of one kind of fuel necessary to evaporate such a given quantity of water as a standard, for a certain quantity of heat is ab

solutely necessary to produce the effect. I have then made the same experiment with coal, and I found that to evaporate a like quantity of water it required two of coke to three of coal; that is, three bushels of coal to evaporate a given quantity of water, whereas two bushels of coke are only required. I have smelted a given quantity of lead ore, and several other kinds of ore, as ore of copper. I have tried it in ore of iron likewise, and I found that when coke was made use of, instead of common coal, I could effect the process in half the time that I could when coal was employed, and little more than half the quantity of coke was necessary to accomplish my object. The coke which I have been able to obtain in the market was of so indifferent a nature, that it hardly could be compared with the coke obtained from Mr. Winsor's stove. A coke fire lighted for the use of houses and families is equally easy as a coal fire, provided the coke has not been charred too much, or has not been exposed to too intense a heat. I should have no objection to use it in my own family, and in my own laboratory, and should give the preference on account of the less trouble it requires, and its longer duration and intensity of heat. There is no smoke at all, hardly; and of course it does not make the same dirt, nor any unpleasant smell attending the use in private rooms in the coke of Mr. Winsor; but in the coke of commerce there is considerable sulphureous odour. By the construction of Mr. Winsor's stove, different kinds of coke may be produced according to the will of the proprietor. Two descriptions of coke, one nearer the fire, and the other further from the action of the fire, are produced in the ordinary operation of decomposing a quantity of coal for producing gas light;