362 Mr G. Merry weather's account of an Apparatus 



account of the process of combustion, but this I leave with de- 

 ference to the more refined chemist ; and I will only venture the 

 conjecture, that it will be found, that the intense heat, produced 

 by apparently such small bodies, is from the combustion of 

 oxygen and hydrogen by the means of spongy platina, and that 

 water will be found to be the product, mingled with a portion of 

 acetic acid, and derived from the spirit. 



As my attention was first drawn to this subject by the writ- 

 ings of a French philosopher, I feel some degree of pleasure in 

 thinking, that when this apparatus is made known to the 

 scientific men in France and on the Continent, it will be freed 

 from the objection of expense, which, in this kingdom, may 

 prove an obstacle, but, ' in the other European States, the ex- 

 pense will be a mere bagatelle. 



I do not present this furnace to the Royal Society as a perfect 

 apparatus, because I am aware that it admits of various im- 

 provements and modifications. My sole object has been to pro- 

 duce a uniform and lasting temperature ; and the means by 

 which I have accomplished this, I have endeavoured to render 

 as simple and as little expensive as possible. If the members of 

 the Royal Society are satisfied that I have done so, it will ever 

 be a gratifying reflection to me, to think, that the few leisure 

 hours I have devoted to this subject have not been spent in 

 vain. I have the honour to be, Mr President and Gentlemen, 

 your most obedient servant, 



George Merryweather. 

 ■ q jj fmri : s,i\ & -f o 



EXPLANATION OF THE PLATE OF THE APPARATUS FOR 

 MAINTAINING UNIFORM TEMPERATURE. 



A. A reservoir made of tin, nine inches in diameter, concave at the bottom 



interiorly, and deep enough to hold one gallon of spirit. The hole at 

 the side and lower part is to connect, by means of a tube, the reservoir, 

 with one containing a larger supply of spirit. This extra supply will be 

 necessary, when an experiment is to be conducted for a length of time. 



B. Are the cotton wicks, which perforate fifteen brass tubes, each of which is 



similar to the brass work accompanying a common spirit lamp. When 

 the wick is drawn through, it is to be spread and flattened. Each wick 

 is to be sufficiently long to touch the bottom of the reservoir. The fifteen 

 brass tubes are to be inserted into fifteen tin tubes, three quarters of an 

 inch in diameter, which are soldered to the top of the reservoir ; namely, 

 vUrelv« in a circle, and three in the centre, the latter to be shorter and 



