46 Experiments upon Gunpowder. 



See the experiments from No. 109 to No. 115, inclu- 

 sive. 



And taking the means of all the velocities in both 

 sets in each position of the vent, it will be, 



Vent at o Vent at 1.3. Vent at 2.6. 



Mean Velocity, 1436 1493 1437 



The mean recoils in these experiments were, 



Vent at o. Vent at 1.3. Vent at 2.6. 



22.88 23.34 23.61 



In the experiments with 310 grains of powder, the 

 velocities of the bullets were not determined with suffi- 

 cient accuracy to be depended on ; but the recoils, which 

 were measured with great nicety, were as follows, viz. 



Vent at o. Vent at 1.3. Vent at 2.6. 



24.69 24.95 2 4-9 



With 330 grains of powder, the mean velocities and 

 recoils were, 



Vent at o. Vent at 1.3. Vent at 2.6. 



Velocities, 1594 1625 1525 



Recoils, 26.075 2< M 2 5-3 . 



In the experiments with 4372 grains (an ounce avoir- 

 dupois) of powder, the velocities and recoils were, 



Vent at o. Vent at 2.6. 



From the result of these experiments it appears that 

 the effect of placing the vent in different positions with 

 respect to the bottom of the chamber is different in 

 different charges ; thus, with 165 grains of powder, the 



