Mr. E. Howard on a new fulminating Mercury. 235 



Exp. 3. It was found so difficult to extract the fragments of the 

 case remaining in the carronade, after the last experiment, that a 

 channel was drilled through them, to the vent-hole of the piece. 

 It was then charged with 6 ounces troy of the mercurial powder, 

 made up as a cartridge, which did not occupy above one half of 

 the diameter of the bore. A wad was placed over the powder, 

 dry sand superadded, to fill all vacuities, and the gun filled to 

 the muzzle with two twelve-pound shot. A block of wood was 

 set at a small distance, to receive the impression of the shot, 

 and the powder was inflamed as usual. The carronade still 

 resisted. One of the shot was split into two pieces ; and the 

 block of wood was driven to a considerable distance, but not 

 penetrated by the shot above the depth of one inch. The 

 report was somewhat louder than the former ones. In all 

 three instances, a considerable recoil evidently took place. I 

 presume, therefore, that in the first experiment related in the 

 fifth Section, there must have been a recoil, though too trifling 

 to be observed; and, in the instances where the gun and the 

 proof were burst, it was not so much to be expected. 



Exp. 4. Finding that the carronade, from the great compara- 

 tive size of its bore to that of its length, required a larger quantity 

 of mercurial powder to burst it than we were provided with, we 

 charged a half-pounder swivel with an ounce and an half avoir- 

 dupois of the mercurial powder, (the service charge of gunpowder 

 being 3 ounces,) and a half-pound shot between two wads. 

 The piece was destroyed from the trunnions to the breech, and 

 its fragments thrown thirty or forty yards. The ball penetrated 

 five inches into a block of wood, standing at about a yard from 

 the muzzle of the gun % the part of the swivel not broken, was 

 scarce, if at all, moved from its original position. 



Exp. 5. One ounce avoirdupois of the mercurial powder 9 



Hh 2 



