Experiments upoji Gunpowder. 47 



velocity of the bullet was rather diminished by remov- 

 ing the vent from o, or the bottom of the bore, to 1.32; 

 but with 218 grains of powder, the velocity was a little 

 increased, as was also the recoil. With 290 grains 

 of powder, the velocity was greatest when the powder 

 was lighted at the vent 1.3, which was near the middle 

 of the charge, and rather greater when it was lighted at 

 the top, or immediately behind the bullet, than when it 

 was lighted at the bottom. And by the recoil it would 

 seem that the velocities of the bullets varied nearly in 

 the same manner when the charge consisted of 310 

 grains of powder. 



With 330 grains of powder, both the velocity and 

 the recoil were greater when the powder was lighted at 

 the middle of the charge than when it was lighted at 

 the bottom ; but they were least of all when it was 

 lighted near the top. And when an ounce of powder 

 was made use of for the charge, its force was greatest 

 when it was lighted at the bottom. But the difference 

 in the force exerted by the powder, which arose from 

 the particular position of the vent, was in all cases so 

 inconsiderable (being, as I have before observed, less 

 than what frequently occurred in repeating the same 

 experiment) that no conclusion can be drawn from the 

 experiments except only this, that any given charge of 

 powder exerts nearly the same force, whatever is the 

 position of the vent. 



And hence the following practical inference naturally 

 ■ occurs, vix. that in the construction of fire-arms no 

 regard need be had to any supposed advantages that 

 gunsmiths and others have hitherto imagined were to be 

 derived from particular situations for the vent, such as 

 diminishing the recoil, increasing the force of the charge. 



