Armor Plate

sheets of metal designed to protect the hulls of ships against the missiles hurled by artillery. The idea appears to have been thought of in the war of 1812, but the first ironclads to engage in actual combat were three ships sent by France in 1855 to Alma, a Russian fort in the Crimea. Naturally enough, the projectile force of cannon was increased. During our Civil War a plate four and one-half inches thick was considered an efficient protection. A few years later the Krupps produced a rifle throwing a steel bolt, fourteen and one-half inches in diameter, that proved itself capable of piercing two twelve-inch plates separated by eleven inches of teak wood backed by five inches of teak and two one-inch plates,--a total protection of twenty-six inches of metal and fourteen inches of teak wood. It was then admitted that a war ship may be strengthened and its most vital parts defended, but that it would sink any ship to cover it with complete gunproof armor. The heaviest steel armor is now made in sections about a foot in thickness, nine feet in width, and eighteen feet in length. The outer surface is hardened. The plates are fastened in place by bolts, entering the inner surface only. Three and one-half per cent of nickel is added to the metal to secure toughness. A large battleship carries 8,000,000 pounds or more of armor. Modern projectiles will pierce any armor now made at a distance of a mile and a half or two miles; but the fact that a projectile is likely to strike at an angle and glance adds to the security of the ship. The principal American mills engaged in the manufacture of steel armor plate are at Pittsburg and South Bethlehem, Pennsylvania. See Battleships; Artillery; Krupp