90 ANNUAL OF SCIENTIFIC DISCOVEEY. 



battery, and a shower of these molten iron shells were fired at them, 

 from a distance, by a 68-pounder. The elFect is represented to have 

 been terrific- ; the shells consumed everything upon which they fell. 

 Three hundred new cupolas, for melting iron for these shells, have 

 been furnished at Woolwich for distribution among the batteries on 

 the British coast. Each cupola consists of an outer shell of plate 

 iron lined with fire-brick, and a fan-blower is used for each, as in all 

 our iron-foundries. The driving-gear of the fan is so constructed 

 that whenever steam-power is available it can at once be applied. 

 When the blast-fan is driven by manual labor, eighteen men are re- 

 quired to work it, with short reliefs. In about twenty minutes after 

 the fire in the cupola is lighted the iron is put in, and in about a quar- 

 ter of an hour after the fan has been put in motion the molten iron 

 can be run off into the shells. A ton of metal can be melted in 

 about thirty minutes. Allowing, therefore, for waste, the number of 

 shells that can be filled in one hour is one hundred and forty of the 

 eight-inch 68-pounders, and the same number of the ten-inch 96- 

 pounders. The estimated weight of the machine is five tons. 



Open-work Rifled Cannon. One of the most singular devices rel- 

 ative to the construction of ordnance is a cannon invented by Mr. De 

 Brarne, of New York. This gun is a breech-loader, the breech having 

 six chambers ; but the barrel, from the trunnions to the muzzle, is 

 formed of bars placed some inches asunder, and rifled inside, and 

 held in place by outside rings, also some inches apart, leaving the 

 barrel open for the air to pass through. The bars direct the ball as 

 accurately as if the barrel were solid, while the free ventilation se- 



V 



cured prevents the gun from becoming unduly heated. 



In answer to the objection which would naturally occur to any one 

 experienced in the use of firearms, that by leaving the barrel open 

 much of the expansive force of the powder would be lost, Mr. De 

 Brame states that in experiments made with two models one in 

 which the barrel was covered and the other not he had found that 

 the projectile would issue with at least as great force from the latter 

 as from the former. 



Terry's Breech-loading Carbine. The British government have 

 recently adopted for use in the cavalry a breech-loading rifled car- 

 bine, known as Terry's, which has the following peculiarities : 



The barrel is twenty-four inches in length, full length thirty-seven 

 and a half inches, and weighs altogether a trifle under six pounds. 

 It has an effective range of over a thousand yards, is sighted for 1,200 

 yards, and will carry a ball or rifle shell i,500 or 1,600 yards, or 

 very nearly one mile. The bore is the same as the Enfield rifle, and 

 fires a similar bullet, conical, one weighing about an ounce. The 

 contrivance for loading and then closing the breech is one that sends 

 a steel plug into the lower end of the barrel about the third of an 

 inch. The ball protrudes naked from one end of the cartridge, and 

 when fired entirely fills the bore and grooves, thus preventing wind- 

 age. It is impossible for it to leak fire. By a singular and ingen- 

 ious contrivance in the cartridge the gun lubricates and cleans 

 itself, and does not become the least foul, even after firing thousands 

 of times. At the lower or base end of the cartridge is a wad, cut out 

 of heavy woollen felting, at least a quarter of an inch thick. This is 



