28 



Experiments upon Gunpowder. 



was gently forced down till it occupied the same space 

 in each experiment. 



The following table shews the heights of the charges 

 as they were determined by measurement, and also their 

 heights computed from the diameter of the bore of the 

 piece, and the specific gravity of the powder that was used. 



N. B. By an experiment, of which I shall give an 

 account hereafter, I found the specific gravity of this 

 powder, shaken well together, to be to that of rain- 

 water as 0.937 is to i.ooo. 



In the experiment No. 30 the powder was put into a 

 cartridge so much smaller than the bore of the piece 

 that the charge, instead of occupying 1.45 inches, ex- 

 tended 3.2 inches. By this disposition of the powder, 

 its action upon the bullet appears to have been very 

 much diminished. 



Of the Effect that the Heat which Pieces acquire in being 



fired produces upon the Force of Powder. 

 It is very probable that the excess of the velocity of 

 the bullet in the second experiment over that of the 



