402 ACTION OF HEAT MODIFlfeD 



trperiment Oil the 1 Uh of April, 1 303, with a barrel of oH fable 



made with the i,-on having a bore of 0.75 of an inch, I made an experi- 



toregorng pre- . • i • i u • r • A- 



cautions. The r^e'it in which all Uiele anangemenls were put in practice. 

 heat amounted The large tube contained two fmall ones; one filled with 

 wood. The* ^P*""' ^"^' the other with chalk. J conceived that the heat had 

 carbonates had rifen to 33'*, or fomewhat higher. On melting the metals, 

 lort gas and un- jj^^ ^^.^jj^ ^,.^^ (hrown out with confiderable violence. The 

 dsrgone rulK-n. 



pyrometer, which, in this experiment, had been placed 



within the barrel, to my aflonilbment, indicated 64-''. Yet 

 all was found. The two little tubes came out quile clean and 

 uncontaminated. The fpar had loft 17.0 per cent, the chalk 

 JO. 7 ptr cent. The fpar was half funk down, and run againft 

 the fide of the iillle tube : Its furface was fliining, its texture 

 Ipongy, and it was compofed of a tranfparent and jelly-like 

 fubftance. The chalk was entirely in a ftale of froth. This 

 experiment extends our power of aflion, by fliewing, that 

 compreffion, to a confiderable degree, can be carried on in fo 

 great a heat as 6^°. Itfeems likevvife to prove, that, ia fome 

 of the late experiments with the fquare barrel, the heat had 

 been much higher than was fuppofed at the lime, from the in- 

 dication of the pyrometer placed on the breech of the barrel; 

 and that in fome of them, particularly in the laft, it muft have 

 rifen at leaft as high as in the prefent experiment. 

 Experiment in O" t'^^ ^'^ of April, 1805, afimilar experiment was made 

 which the barrel ^yith a new barrel, bored in a fquare bar of old fable, of about 

 conteuti had un- '^^^ ^^^ ^ ^^'^ '"*-^ '" diameter, having its angles merely 

 «{ergyne fafion. rounded ; the inner tube being filled with chalk. The heat 

 was maintained during feveral hours, and the furnace allowed 

 to burn out during the night. The barrel had the appearance 

 of foundnefs, but the metals came off quietly, and the carbon- 

 ate was entirely calcined, the p}rometer indicating 63", On 

 examination, and after beating off the fmooth and even fcaie 

 of oxide peculiar to the old fable, the barrel was found to have 

 yielded in its peculiar manner; that is, by the opening of the 

 longitudinal fibres. This experiment, nolwilhftanding the 

 failure of the barrel, was one of the moft interefting 1 had 



of this tin with an equal bulk of water, I found that a cubic inch 

 of it weighed 1330. G grains, and that each grain of it conefponded 

 to G. 00075 of a cubic inch. From thefe data I was able, with to- 

 lerable accuracy, to gage a tube by weighing the tin required to 



fill it. 



made, 



