ARX0R-PLATES, The employment of thick slabs of iron to protect the sides of ships of war and the fronts of fortifications, is quite a recent invention; or rather, the modern system is the practical realization of plans suggested long ago by itlersenne and others. In 1842, Mr. Baltuano of New York proposed that war-ships should be clad with several thicknesses of iron plate, riveted one upon another, the plates being indi vidually Ith inch thick. Soon afterwards, Mr. Stevens, an American ship-builder, made further suggestions on the same subject, and other practical men kept the matter before the attention of the authorities in various countries. In 1854, the French sent several floating-batteries to the Black sea, clad with iron plates; and the English admiralty hastily imitated this example, producing eight very slow and unmanageable batteries in 1855-56. Then came in a flood of suggestions for arming our regular ships of war in a similar way. The admiralty, dismayed at the thought of dismantling the existing fleet, which had cost so much, delayed the subject as long as they could, but without abandoning it. In 1860, the French sent to sea La Gloire, a timber-built ship of war, altered from a 90-gun three-decker to a 40-gun corvette; clad with 4i-inch iron plates, having a burden of 3000 tons. This proceeding at once set the English gov ernment on the alert; they saw be imprudent, and they set about the creation of an armor-clad navy. Many problems had to be solved— whether to case old wooden ships with armor; to build and case new wooden ships; or to build new vessels, bf which the bull as well as the armor should be of iron. Then arose further problems—how near the bulwarks should the armor-plates come, how near the bottom of the vessel, how near the stein and stern; also, what thickness of iron, and whether the same thickness in every part.
From 1861 to 1876, the British Admiralty were engaged on a series of costly construc tions and reconstructions, intended to afford eventually solutions to the above problems. Several of the ships built have cost from £300,000 to £450,000 each; several half-finished timber three-deckers have been cut down and converted into iron-dads; and variations of detail almost innumerable have been introduced. The following is a list of English
vessels which in 1876 formed the iron-clad navy. Those which are wholly clad—i.e., covered with armor-plates in all parts of the hull needing protection—are the 3finotaur, Agincourt, Northumberland, Royal Oak, Prince Consort, Caledonia, Ocean, Lord Clyde, Lord Warden, Audacious, Invincible, Prince Albert, Scorpion,Wyvern„Vonarch, Iron Duke, Sultan, Glatton, Cyclops, Hecate, Hydra, Gorgon, Dreadnought, Devastation, Thnnderer, Swiftsure, Triumph, Rupert, Hotspur, Hercules, Inflexible, Alexander, and Shannon. Those which arc partially covered with armor-plates only in the more exposed por tions—comprise the Black 7Prince, Warrior, Defense, Resistance, Achilles, Hector, Valiant, Royal Alfred, Bellerophon, Zealous, Pallas, Favorite, Research, Enterprise, Viper, Vixen, Waterwitch, Penelope. Regarded as to the material of which the hulls are mostly built, and on which the armor-plates are laid, the following are timber-built: Royal Oak, Prince Consort, Caledonia, Ocean, Royal Alfred, Zealous, Lord Clyde, Lord Warden, Pallas, Favorite, Research, and Enterprise. The Vixen is wood and iron; the Thmftsure and Triumph are iron sheathed with wood; all the rest are iron. The dimensions and weight of these ships, laden with armor-plates from 3 to 24 in. thick, are enormous. The load displacement of five of them exceeds 10,000 tons each; six, 9000 to 10,000; four, 7000 to 9000; twelve, 6000 to 7000; seven, 4000 to 6000. Some of the steam-engines for these ponderous ships, nominally of 1200 horse-power, work up to (indicated) 8000 h.p. Whatever the thickness of the armor, the plates are nicely tongued and grooved to fit closely together edgewise. The bolts which fasten them to the ship are generally 2 to 2i in. thick, expanded at one end to form a head, and having a screw-thread at the other to receive a nut.