SIR ANDREW NOBLE: RESEARCHES ON EXPLOSIVES. 



217 



The heat capacities of the explosion vessels were carefully determined, as were 

 those of the calorimeters and their equipage, including the stirrers and the mercurial 

 thermometers. The latter were of the differential type described by Professor 

 OSTWALD, those I used having a range of about 8 C. Two observations for each 

 density were sufficient if the observations were accordant. If not accordant, three 

 were generally taken. 



Not unnaturally, the observations at the higher densities were considerably more 

 accordant than those at the lower. 



Commencing with the Chilworth R. R. nitrocellulose (tubular) in Experiment 1344, 

 9'17 grammes were fired, the explosion vessel, when fired, being suspended in 

 4000 grammes of distilled water in the calorimeter, the water equivalent of the 

 explosion vessel and the calorimeter being 680 cub. centims. It was then found that 

 immediately before explosion the calorimeter differential thermometer showed 1'1G1 

 (equivalent to 19 '9 C.). 



C. 



It will be observed that the maximum temperature reached was. . 3 '057 

 Subtracting temperature before explosion 1'161 



we have 1'896 



Adding correction for lost heat during rise 0'010 



1-906 

 Hence ^ = 9727 heat units. 



VOL. CCV. A. 



2 F 



