284 Mr. Thompson’s Experiments 
what it was in the 76th and 77th experiments before mention cf, 
when the velocities fhewn by the recoil and by the pendulum 
were almofd exadliy the fame, I am inclined to believe, that 
there muff have been fome miftake in determining the velo- 
cities by the pendulum in thefe laid experiments, and that the 
•velocity fhewn by the recoil is mold to be depended on. 
With 290 grains, or half the weight of the bullet in pow- 
der, in the 48th, 49th, and 50th experiments, the recoil was 
22,58, 22,92, and 22,38 ; and the recoil, with the fame charge 
of powder, without a bullet, at a mean of the 60th and 
99th experiments, was 10,66. The mean of the velocities 
of the bullets, computed from the recoil, is therefore 1416 
feet in a fecond, and the velocity fhewn by the pendulum was 
1427 feet in a fecond : the difference is not confiderable. The 
mean of the velocities in the icpth, 110th, mth, jand 
112th experiments is by the recoil 1464, and by the pendu- 
lum 1444 feet in a fecond. 
With 330 grains of powder the velocities of the bullets 
appear to have been as follows, viz. 
Vent at o. Vent at 1,3. Vent at 2,6. 
Bytherecoil 1543 1620 1610 
By the pendulum 159 4 1625 1528 
See the 62d, 63d, 64th, 65th, 66th, 67th, and 17th 
•experiments. 
The uniformity of the recoil was in all cafes very remarkable. 
Thus, in the firft fet of experiments with 290 grains of pow- 
der (from the 48th to the 57th experiment inclufive), the recoil 
was s 
Vent 
^3, * ■>* 
