SIR ANDREW NOBLE: RESEARCHES ON EXPLOSIVES. 
465 
that if the explosives be arranged according to the amount of heat generated, derived 
from equation (l), regard being also had to the amount of C0 2 found, it will be found 
that the differences between the two formulse decrease approximately as the factors 
to which I have referred decrease, as is shown in the following table :— 
( 1 ) 
Explosives. 
( 2 ) 
Temperature 
of formation 
derived from 
equation (1). 
Density = 0‘05. 
( 3 ) 
Percentage 
of CO,. 
( 4 ) 
Temperature 
reduced by 
dissociation 
derived from 
equation ( 2 ). 
Density = 0-05. 
( 5 ) 
Difference of 
temperature. 
° C. 
°C. 
0 C. 
Italian ballistite . . . 
4943 
37 05 
2745 
2198 
Cordite Mark I ... 
4742 
27-20 
2800 
1942 
M.D. 
3814 
18-40 
2345 
1469 
Norwegian 167 . . . 
3748 
18-45 
2200 
1548 
Norwegian 165 ... 
3410 
15-60 
2000 
1410 
Nitrocellulose .... 
3213 
17-95 
2260 
953 
The differences given in column (5) of the above table represent, for the very low 
density of 0*05, the differences which I suppose to be due chiefly to dissociation, but 
partly to the communication of heat to the explosion vessel—but these differences are 
very considerably less if the mean density giving rise to the maximum pressure in the 
bores of guns is taken. Thus with Italian ballistite the difference between the two 
formulae is approximately 1210° C. ; with cordite Mark I, 860° C. ; with M.D., 
560° C.; with Norwegian 167, 600° C. ; with Norwegian 165, 510° C. ; and with 
nitrocellulose R.R., 480°. 
At the density of 0*45 the differences between the two formulae are as follows :— 
Italian ballistite ....... 
° C. 
150, 
Cordite Mark 1 ...... 
200, 
M.D. 
320, 
Norwegian ballistite 167 . 
• 55 
250, 
Norwegian ballistite 165 . . . . 
• 55 
130, 
Nitrocellulose. 
180. 
It will be observed, both from the above figures and the curves, that with the 
Italian ballistite alone at the density 0'45 is the temperature derived from equation (2) 
lower than that derived from equation (1). With all the other explosives the 
temperatures derived from equation (2) are the higher. The differences, however, 
are not great, being generally under 5 per cent., that is about 200° C. 
In the case of experiments carried on, both at pressures and temperatures very 
greatly above the limits at which physicists ordinarily experiment, I can hardly hope 
VOL. CCVI.—A. 3 O 
