22 Experiments upon Gunpoivder. 



The bullet made use of in experiment No. 85 was 

 of wood. 



Those used in the experiments No. 86 and No. 87 

 were formed in the following manner: a small bullet 

 was cast of plaister of Paris, which, being thoroughly 

 dried and well heated at the fire, was fixed in the center 

 of the mould that served for casting all the leaden 

 bullets used in these experiments ; and melted lead 

 being poured into this mould, the cavity that surrounded 

 the small plaister bullet was intirely filled up, and a 

 bullet was produced, which to the eye had every ap- 

 pearance of solidity, but was as much lighter than a 

 solid leaden bullet of the same diameter as the small 

 plaister bullet was lighter than a leaden bullet of the 

 same size. 



In the experiments No. 88 and No. 89 solid leaden 

 bullets were made use of. In the experiment No. 90 

 two bullets were discharged at once ; in the experiment 

 No. 91 three, and in the experiment No. 92 four were 

 used. 



In each of these experiments a fresh sheet of pa- 

 per was made use of as a screen to the pendulum, in 

 order that the velocities of the bullets might be 

 measured more accurately ; and also that the quantity 

 of unfired powder might be estimated with greater pre- 

 cision. 



