270 
Mr. Thompson’s Experiments 
Of the relation of the velocities of bullets to the charges of powder 
by which they are impelled. 
It appears by all the experiments that have hitherto been 
made upon the initial velocities of bullets, that when the 
weights and dimers lions of the bullets are the fame, and they 
are difcharged « from the fame piece by different quantities o'f 
powder, the velocities are in the fub- duplicate ratio of the 
weights of the charges very nearly. 
The following table will (hew how accurately this law ob- 
tained in the foregoing experiments. 
V elocities 
Charges. 
437 i 
Computed. 
1764 
Actual. 
I 764 
Difference. 
N° of exp, 
n 
0 
33 ° 
1 533 
1594 
■ - 1 - 6 1 
0 
-fa* 
3 l ° 
1 486 
■ I 459 
“ 27 
I 
290 
14 36 
1436 
0 
7 
218 
1 232 
1225 
- 7 
4 
208 
1216 
1 256 
+ 40- 
3 
1 65 
1083 
1087 
T 4 
2 
i 45 
1018 
104a 
+ 22 
2 
104 
860 
757 
- I0 3 
2 
The computed velocities, as they are fet down in this table, 
were determined from the ratio of the fquare root of 437I 
weight in grains of the largeft charge of powder) to the 
mean velocity of the bullet with that charge and the vent at 
o ; viz. 1 64 feet in a fecond, and the fquare root of the other 
charges exp refled in grains . And the aBual velocities are means 
of all experiments that were made under fimiiar circumftances. 
5 The 
