Experiments upon Gunpowder. 55 



290 grains of powder (from the 48th to the 57th experi- 

 ment inclusive), the recoil was. 



Means 



If now we take a mean of the 6oth and 96th experi- 

 ments, and call the recoil, without a bullet, 10.66, as 

 before, the velocities will turn out, 



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



Bv the recoil, 1416 1501 1494 



And by the pendulum they were 1427 1493 1460 



The difference is only — 11 -j- 8 4~ 34 



The recoil was equally regular in the 117th and five 

 succeeding experiments, when the charge was no less 

 than 437^- grs. = i ounce avoirdupois in powder ; and 

 the velocities of the bullets determined from the recoil 

 are very nearly the same as they were shewn by the pen- 

 dulum. Thus, in the 117th, 11 8th, and 119th experi- 

 ments the mean recoil was 33.3 : and in the 120th, 121st, 

 and I22d experiments it was 32.866. And if the recoil 

 without a bullet be called 17.9, as it was determined by 

 the 123d experiment, which was made immediately after 

 the experiments before mentioned, then will the veloci- 

 ties be, 



in a second, which is less than what frequently occurs in 

 repeating the same experiment. 



