174 Experiments with Cannon^ ^c. 



trated by accurate plans (which are now ready for the 

 engraver), of all the changes in the construction of the 

 Bavarian artillery, which were introduced in my at- 

 tempts to improve it, during the time the military af- 

 fairs of that country were under my direction. In the 

 mean time I have thought it advisable to give, in this 

 place, a short account of such of my experiments as are 

 most intimately connected with the subjects of the two 

 preceding papers ; and this I shall now do in as io,"^ 

 words as possible. 



Pieces of brass ordnance, of three different calibres, 

 viz. 3 pounders, 6 pounders, and \i pounders, having 

 been suspended, in an horizontal position, by long 

 pendulous rods, or bars of iron, in the manner de- 

 scribed in one of the foregoing papers, these guns were 

 fired in this situation, with different charges of powder ; 

 with, and also without bullets ; and sometimes with 

 two and with three fit bullets at the same time ; and 

 the velocity of the gun in its recoil having been deter- 

 mined, in each experiment, by the length (measured by 

 means of a ribband) of the chord of the ascending arc 

 of its first vibration, from that velocity, and the known 

 weights of the gun and of the bullet, the velocity of 

 the bullet was computed. 



The gun having been pointed against the center of a 

 very large heavy pendulum, constructed of strong tim- 

 bers, well fastened together with iron, the bullets lodged 

 in that pendulum ; and their velocities were determined, 

 according to Mr. Robins's method, by the. arcs of the 

 vibration of the pendulum ; and these two methods of 

 ascertaining the velocities of the bullets were found to 

 agree with great accuracy. 



This pendulum, although it was made very strong. 



