Experiments upon Gunpowder. 57 



The charge of powder consisted of 145 grains in 

 weight in each experiment. 



In order to shew in a more striking manner the re- 

 sult of these experiments and the comparison of the two 

 methods of ascertaining the velocities of bullets, I have 

 drawn the Fig;. 16 where the numbers that are marked 

 upon the line AB are taken from A towards B, in pro- 

 portion to the weights of the bullets ; while the lines 

 drawn from those numbers, perpendicular from AB 

 (as w, V, for instance at the number 2352) and ending 

 at the curve c^ d, express their velocities as shown by the 

 pendulum. The continuations of those lines on the op- 

 posite side of the line A B shew the recoil, and also the 

 velocities of the bullets as determined from it : thus 

 w, r, and the (dotted) lines parallel to it, which end at 

 the line g, /, express the recoil ; and the portion of each 

 of those lines that is comprehended between the line 

 AB and the curve m, n, (as w^ z/,) is as the velocity of 

 the bullet in the several experiments. The line A, e^ 

 denotes the weight of the charge of powder; and the 

 line A, m, the velocity with which the elastic fluid escapes 

 out of the piece, when the powder is fired without any 

 bullet. 



