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



conformity to this opinion, a cast iron case was constructed, 

 with a cylindrical chamber, of equal length and diameter, calcu- 

 lated to hold 3^th ounces troy of the mercurial powder. The 

 case, being firmly screwed together, was charged through its 

 vent-hole, and introduced into a twelve-pounder carronade, the 

 bore of which it exactly fitted. The powder was then enflamed, 

 with proper precautions. The gun remained entire, but the case 

 divided : the portion forming the upper surface of the chamber, 

 was expelled in one mass ; that adjoining the breech, which con- 

 stituted the rest of the chamber, was cracked in every direction, 

 and in part crumbled ; yet it was so wedged into some inden- 

 tations which the explosion had made in the sides of the piece, 

 that the fragments were not removed without great labour. 



Exp. 2. Another cast iron case was prepared, of the same size 

 as the former, with a chamber also cylindrical, but wrought in a 

 transverse direction, and of a greater length than diameter ; the 

 thickness of metal at each extremity not being more than a 

 quarter of an inch. This case was filled with nearly 5 ounces 

 troy of the mercurial powder, and placed in the same carronade. 

 Three twelve-pound shot were next introduced, and brought into 

 close contact with the upper surface of the case, as well as with 

 each other. The gun a second time withstood the explosion : 

 the case was divided across the middle of the chamber, into two 

 equal parts ; that adjoining the breech was, as in the former 

 experiment, much flawed, and left immoveable ; that nearest to 

 the muzzle was also much flawed, but driven out with the shot. 

 All the three shot were broken ; the two lower being divided into 

 several pieces, and the upper one cracked through the centre. 



The report was so feeble, in both experiments, that an in- 

 attentive person, I am confident, would not have heard it at the 

 distance of two hundred yards. 



