ing of 80-ton muzzle-loading rifled ordnance in the 'Inflexible':—
Diameter of Bore | Weight of Gun. | Charge of Powder. | Weight of Projectile. | Velocity at Muzzle. | Penetration of Iron at 1000 Yards. |
---|---|---|---|---|---|
Ins. 7 |
Tons. 6½ |
Lbs. 30 |
Lbs. 110 |
Ft. per Sec. 1500 |
Ins. 7 |
8 | 9 | 35 | 180 | 1400 | 8 |
9 | 12 | 50 | 250 | 1400 | 10 |
10 | 18 | 70 | 400 | 1380 | 12 |
11 | 25 | 85 | 540 | 1320 | 13 |
12 | 35 | 140 | 700 | 1400 | 15 |
12.5 | 38 | 200 | 800 | 1550 | 17 |
16 | 80 | 450 | 1700 | 1600 | 23 |
A few words must now be said about the ammunition. Experiments had shown that against armour cast-iron shot broke up like a snowball, while forged wrought-iron projectiles flattened, as if made of lead, against the hard or comparatively hard surface. In both cases the iron plates suffered little, because the energy was expended in breaking or distorting the missile. In this dilemma Captain Palliser came to the rescue with his ingenious device of hardening the front portion of a shot by chilling. The body is cast in an earthen mould, but the head is formed by a metal mould, which rapidly extracting the heat in this portion gives great hardness to the material. The result is