MECHANICS AND USEFUL ARTS. 75 



being actually too large for it, that there is no windage whatever, and every 

 portion of the explosive force is applied to projecting the ball. The gun on. 

 which the government experimented for months before adopting it, was 

 actually fired 3500 times, and was then returned as still serviceable. 



In a speech made by the inventor at a banquet given in his honor, at New- 

 castle, England, he describes some peculiarities of the gun as follows: The 

 projectile for field purposes admits of being used indifferently either as solid 

 shot or shell, or common case or canister. It is composed of separate pieces, 

 bound together so compactly that the shell has been fired through a solid 

 mass of oak timber nine feet in thickness, without sustaining a fracture. 

 When used as a shell it divides into forty-nine separate regular pieces, and 

 into about one hundred indefinite and irregular pieces. It combines the 

 principle of the shrapnel and percussion shell. It either explodes as it ap- 

 proaches or as it strikes the object. The percussion arrangement is, that 

 the shell, while in the hands of a friend, is so safe and quiescent that it may 

 be thrown off the top of a house without exploding; but when among 

 enemies, it is so sensitive and so mischievous that the slightest touch will 

 cause it to explode. 



The reason of this is, that the shock which the projectile sustains in the 

 act of firing puts the percussion arrangement from half to full cock, and it 

 then becomes so delicate that a shell has been exploded by being fired 

 against a bag of shavings. Moreover, the fuse may be so arranged that the 

 shell explodes at the instant of leaving the muzzle. In that case, the pieces 

 spread out like a fan, and act as grape shot. 



Two targets, nine feet square, were placed at a distance of 1500 yards from, 

 the gun, and seven shells fired at them; the effect of these seven shells was, 

 that the two targets were struck in 596 places, and with so much force that 

 although one of the targets was three inches thick, it was riddled through 

 and through with the fragments. Similar effects were produced at much 

 longer distances, extending in some cases to 3000 yards. I leave you to con- 

 ceive what would be the effect of these projectiles in making an enemy keep 

 his distance. For breaching purposes, or for blowing up buildings, or for 

 ripping a hole in the side of a ship, a shell of a different construction is used. 



FREXCH RIFLED CAXXOJf. 



The rifled cannon introduced by Napoleon III., and used with such effect 

 in the recent battles in Italy, were of bronze, loaded at the muzzle, and of 

 two calibres, 12 for siege, 4 for field guns. 



They each have six twisted rifles, the rifles being about an inch wide and 

 the third of an inch deep. In the bottom there is a narrow chamber to re- 

 ceive the powder, like the carbine of Delavigne, and like the old shell-guns, 

 still in use in the French artillery. The projectile rests on the border of this 

 chamber. This projectile is of a cylindro-spherical form, resembling the ball 

 of the infantry; is in iron, and is hollow and conical, like the latter. The 

 cylindrical base of the bullet is pierced in six places, and into these six drills 

 are introduced as many plugs of pewter. It is these six pieces of pewter, 

 placed in the circumference of the base of the ball, and corresponding to 

 the six rifles of the gun, which perform the important duty of " slugging." 

 They are forced into the rifles by the explosion of the powder, and thus give 

 to the bullet the precision and the force of the carbine ball. 



So'metimes the projectiles are filled with balls, and are made to explode at 



