F, A. P. Barnard on the Explosive Force of Gunpowder. 247 
From which we deduce 
263nS, 
3c?8, ° 
The specific gravity of cannon powder, compacted as it is in 
the gun, is 1:089. That of cannon shot is 7. Substituting these 
numbers, 
3 
Tmt4o1 en, 
c 
And if m represent the fractional part of 7 occupied by a, we 
obtain 
63 
a=4'491 3 mn, 
c 
Substituting then, in the equation for velocity, the value of 
; and also that of a in the factor without the bracket, there 
will result, 
b3gmnp art _grl 
G1 G-neerS, wri 
v2? = 2 152°616 4491 
$2 
c 
in which reduction we put 7=1°89, as deduced by Messrs. Bunsen 
and Schischkoff, and employ for m the value ‘52856, which will 
presently be shown to be just. We have therefore, finally, 
; b | np arl—-arl 
v==92°4029 * 3-pn . eke . 
v2 ec? 3-+n zy-1 
——y 
P= 3538-27 "82° 0 n “erFi—arl 
And 
and that of the latter by the inertia of both the projectile and 
nst the projectile. 
This effect may balance, or more than balance, the former, so 
vity of the sires sa always in the middle of its length. 
ore the explosion, the position of the common centre of 
