Experiments ivith Cannon, &c. 175 



was, however, soon destroyed by the bullets ; but it was 

 not rendered useless till after a sufficient number of ex- 

 periments had been made with it to establish, beyond all 

 doubt, the accuracy of the proposed method of deter- 

 mining the velocities of cannon bullets by the- recoil of 

 the gun. As soon as this was done, the pendulum, 

 being no longer wanted, was removed, and .the bullets 

 were fired into a mound of earth, which had been 

 thrown up to receive them. 



The general results of this course of experiments 

 were as follows : With the same charge of powder, the 

 velocities of two and three fit bullets, discharged at 

 once from the cannon, were found to be greater than 

 the velocity of a single bullet, impelled by the given 

 charge, in a proportion considerably higher than that 

 determined by Mr. Robins. 



Means were employed, which prevented entirely the 

 escape, by windage, of the elastic fluid generated from 

 the powder in its combustion, and this added very con- 

 siderably to the apparent force of the charge. 



The force of the charge was always sensibly increased 

 when the gun was discharged by firing a pistol (con- 

 structed for that use) into the vent, instead of using a 

 priming and a common match for firing off the gun. 



As I have entered upon this subject, and as it is pos- 

 sible that I may never find leisure to finish the work on 

 Artillery, which, for many years, I have had in hand, I 

 cannot resist the inclination I feel to avail myself of 

 this opportunity to submit to the public but more 

 especially to professional men some of the principal 

 results of my experiments and meditations in the prose- 

 cution of my inquiries relative to the improvement of 

 artillery. 



