ARMOR PLATE. The protection of ves sels of war by metallic plating began soon after the introduction of heavy guns on board ship, but was a matter of little importance until the introduction of shell-fire and the increased power of guns made the protection afforded by thick wooden sides wholly inadequate. The demand for armor became more imperative as time went on, owing to the greater use of machinery and apparatus which needed protection, even against comparatively small guns; and, in recent years, its use has been further stimulated by the intro duction of guns of the rapid-firing types. The first important use of armor plate was made in the operations against Gibraltar in 1782. The Chevalier d'Arcon had caused to be constructed 10 floating, batteries of 600 to 1200 tons, armed with 10 to 20 gulls each. The hulls were of wood, protected with bars of iron laid on at short intervals, with an outer covering of cork. Sand was placed in the spaces between the bars, and it was to be kept wet to avoid danger of fire from red-hot shot. The deck over the guns was of very solid construction, and covered with think green hides. At the attack on Gibraltar of September 13, 1782, one of the vessels took fire, and, as they were moored very close together, the conflagration spread to the others, and they were all destroyed. No provision had been made for extinguishing file, as it was thought the means to prevent it were ample. Boats, even, were not supplied, so that of the 5260 men who formed the crews, only 487 were saved. Subse quent to this were many suggestions as to the employment of armor plating. About 1812, Col. John Stevens, of New Jersey, prepared plans for an armored steam vessel for harbor defense. Explosive shells. which had hitherto been used only in mortars, were in 1824 prepared for service in the ordinary smooth-bore guns of the French ships: and at that time General Paix hans. in an official letter to the French Govern ment, predicted that this new departure would force the creation of armored ships. About 1830 the French Government began experiments (the first were carried out. at Metz) to determine the resistance of earth, wood, and different types of masonry to the penetration of spherical projec tiles. These experiments were continued at in tervals for several years, and the results ob tained are still considered of some value.
In 1841. General Faixhans, who invented the shell for low-angle fire, recommended the appli cation of armor plate to the sides of vessels as a protection against his own missiles. His plans were rejected, lint they attracted much attention. Ill 1841, also, the sons of Col. John Stevens pro posed to the United States Navy Department to build an ironclad steamer of high speed, in which all of the machinery, including the propellers, was to he below the water-line. The proposal accepted, and the act of Congress, approved April 14, 1842, authorized the Secretary of the Navy to "contract for the construction of a war steamer, shot and shell proof, to be built princi pally of iron, upon the plan of the said Ste The Stevens brothers had been carrying on armor experiments of their own, and as a result of them had decided that a thickness of 4.5 inches would he sufficient to render the new vessel invulnerable. Just as the Stevens ship was about to be commenced the performances of John Ericsson's large wrought-iron gun showed that 4.5 inches of laminated armor was insufficient for the purpose in view, so that when the Stevens battery was finally begun in 1854— two months before any armored craft in Europe had been laid down—it was as a larger vessel than that originally designed, in order to carry armor of 6.75 inches. The Stevens battery was never completed, largely because general inter est in the project subsided, but specifically be cause Congress refused further appropriations.
In 1841 Theodore IL Timby submitted to the United States War Department plans for a revolving armor-plated battery, and in 1843 he filed a caveat for "a metallic revolving fort, to be used on land or water, and to be revolved by propelling engines located within the same, and acting upon suitable machinery." In 1845 M.
Dupuy de Lome submitted the plans of an iron hulled armor-plated frigate. He believed that by substituting iron for wood he could reduce the weight of the hull from 42 per cent. of the dis placement to 23, and this saving would be suffi cient to give the ship an armor belt S feet wide and 6.5 inches thick. The plans were rejected on the ground that Ile had overestimated the weight . which would be saved, that, even if the pro posals were feasible, a 6.5-inch hilt was not in vulnerable, and that, moreover, the battery was left without protection. In IS4G, the French con structors were called upon for plans of an ar mored floating battery for coast defense. One of these provided for an iron hull and was at first accepted, as the light hull permitted an increased thickness of armor, hut it was finally rejected on account of the anticipated deteriora tion and loss of speed from the fouling of the bottom. No steps were taken to build any of the batteries at this time; but at the outbreak of the Crimean War the plans of the batteries were again taken up and experiments with armor were begun at Vincennes to determine what the proper kind should be. l'hese tests resulted in showing the inferiority of laminated plating as compared with solid plates of the same thiek ness. Solid plates 4 inches thick were broken, but not pierced, by both 32-pounder solid shot and S-inch and 9-inch hollow shot. It was there fore decided to armor the batteries with 4.5-inch plates. About 1846 or 1347, Lieutenant Hunter, of the United States Navy, brought out a plan of an armor-deck for the protection of the ma chinery of vessels, and it very closely resembled, in all its features, the protective deck of thirty years later. In September, 1854, the French Government began the construction of several of the armored floating batteries fitted with weak auxiliary steam - power, for which designs had been prepared some years before. Three of them took part — the principal part — in the attack upon the Russian batteries at Kinburn. October 17, 1855. While practically uninjured them selves. they were able to lie so close to the enemy's works, S00 yards away only, that they dismounted nearly half his guns and compelled him to surrender after four hours' firing, though these batteries had held at hay the combined wooden fleets of France and England for months. The plans of these armored vessels were sent to England by the French Emperor. After consid erable opposition and delay the Admiralty began the construction of similar vessels, hut they were completed too late to join in the attack on the Kinburn forts, as they did not reach the Crimea until October 24, seven days afterwards. The success of the French armor-clads was followed at once by renewed and widespread interest in the armoring of ships. The French Conseil des Travaux de la Marine then determined to con struct some sea-going armor-clads. Before elab orating a design, further experiments were made with armor plates, which resulted in the adop tion of armor five inches thick. The thickness of plating and the general features of the design having heen decided upon, plans were invited. Those of constructor Audenet were accepted, and were carried into effect by the building of the CO it /On c. In the meantime. M. Dupuy de LOme had been studying the results of the recent armor trials. In November, 1857, he laid his plans and proposals before the Government, and in March. 1858, was begun the conversion of the 13-knot, 5000-ton wooden line-of-battle ship Napoleon into an armor-clad. The armor was applied very liber ally, extending from well below water to the deck above the battery; the water-line belt being 4.75 inches thick, backed by 26 inches of oak, and the armor of the battery 4.5 inches thick with 24 inches of backing.