On a new fulminating Mercwy, 129 



there ninft liave been a recoil, though too trifling to be ob- 

 fervcd ; anil, in the inftances where the gun and the proof 

 were burft, it was not fo much to be expeftcd, 



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

 parative fize of its bore to that of its length, required a larger 

 quantitv of mercurial powder to burft it than we were pro- 

 vided with, we charged a half-pounder fu ivel with an ounce 

 and a half avoirdupois of the mercurial powder, (the fervice. 

 charge of gunpowder being three ounces,) and a half-pound 

 fliot between two wads. The piece was deftroved from the 

 trunnions to the breech, and its fragments thrown thirty or 

 forty yards. The ball penetrated five inches into a block of 

 wood ftanding at about a yard from the muzzle of the gun ; 

 the part of the fwivel not broken, was fearce, if at all, moved 

 from its original pofition. 



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

 inclolcd in paper, was placed in the centre of a fliell 4,4 

 inches in diameter, and the vacant fpace filled with dry fand. 



The fliell burft by the explofion of the powder, and the 

 fragments were thrown to a confiderable diftance. The 

 charge of gimpowder employed to burft fliells of this dia 

 meter, is five ounces avoirdupois. 



Exp. 6. A fea grenade, ^,^ inches diameter, charged like 

 the fliell in the laft experiment, was burft into numerous 

 fragments by ^ of an ounce avoirdupois of the mercurial 

 powder. The fragments were projected with but little force, 

 and only to the diftance of eight or ten yards. The charge 

 of gunpowder required for grenades of thia fize, is three 

 ounces. 



Exp. 7. A fea grenade, of the fame diameter as the lafl 

 mentioned, and charged in the like manner, with i-ofan 

 ounce avoirdupois, or 57 j- grains, of the mercurial powder, 

 was fplit into two equal pieces, which were not thrown fen 

 inches afunder. 



The report in the four laft experiments was very fliarp, but 

 not loud in proportion. 



It Iccms, from the manner in which the fwivel was burft, 

 in the fourth experiment, that a fmaller charge would Jiave 

 been fufticicnt for tlie purpofe. We may therefore infer. 



Vol. Vir. S both 



