3 1 % Mr. T&oMPsctds Experiments 
Weight of 
the bullet. " 
Velocity of 
the bullet.. 
Collective 
preffure. 
Powder 
inflamed. 
85 th exp. 
96 grs. 
[ 
2IO9 
0,2581 
37 g rs - 
86th 
25 1 
r 
1430 
0,3310 
48 
87 th 
VO 
CO 
1288 
0,3778 
55 
88th 
600 
1240 
0,5949 
86 
89 th 
603 
1.224 
0,5825 
84 
90th 
1184 
1017 
0,7897 
114 
91ft 
*754 
8 93 
0,9020 
l 3* 
BuMhere are many reafons to fuppofe, that the diminution 
©f the action of the powder upon the bullet, when it is lighter, is 
not fo much owing to the fmallefs of the quantity of powder 
that takes fire in that cafe as to the vis inertia of the generated 
fluid. ,, It is true, that a greater portion of the charge takes 
fire when the bullet is heavy than when it is light, as I found 
in tile very experiments of which I am nowfpeaking ; but then 
the quantity of un fired powder in any cafe was much too fmall 
to account for the apparent diminution of the force when light 
ballets were made ufe of 
e llf the elaftic fluid, in the aftion of which the force of 
powder confifts, were infinitely fine, or if its weight bore no* 
proportion to that of the powder that generated it ;; and if the 
grpfs matter, or caput mortuum , of the powder remainedfin the 
bottom of the bore after the explofion, then, and upon no 
other fuppofition, would the preffure upon the bullet be in- 
verfely as the fpace occupied by the fluid : but, it is evident that 
this can neyer be the cafe. 
A~ curious fubjed for fpeculation here occurs : how far would 
it be advantageous, were it poffible, to diminifh the fpecifiq 
gravity of gun-powder, and the fluid generated from it, with- 
; 3 out 
