The year 1869 was remarkable for the introduction into the British Navy of large ironclads without masts or sails and relying upon steam alone for their propulsion, and these vessels also demonstrated the most perfect form then understood of the turret ship as applied to a sea-going warship of large capacity. The _Devastation_, built at Portsmouth, and the _Thunderer_ at Pembroke, were the first of this class, and were claimed to be more formidable than any other warships in existence both for offence and defence. They were each of 285 feet in length and 4406 tons, as compared with the first ironclad _Warrior_, 380 feet and 6019 tons, and the _Minotaur_, of 400 feet length and 6021 tons. The _Warrior’s_ armour was 4¹⁄₂ inches of hammered plate that would break under the impact of heavy shot; that of the _Minotaur_ was 5¹⁄₂ inches of rolled armour, in each vessel there being a strong backing of teak and iron plating built into the frame. The two turret ships had 12 inches of rolled armour plating on a teak backing built into an immensely strong framing 18 inches thick, and the whole was backed up with an inner skin of iron plating 1¹⁄₂ inches thick. The thickest armour then in use in the French Navy was 8¹⁄₄ inches and was carried only by rams of the _Bélier_ class. These vessels also included an improvement in the bracket-frame system of construction, first introduced in the _Bellerophon_ by Mr. Reid. The “breastwork monitor” of the _Devastation_ type was regarded as an improvement on the American types of monitors. The turrets were mounted on Captain Coles’ system and each turret carried two 30-ton guns. The ships were driven by independent twin-screws and had a speed of 12¹⁄₂ knots. In 1870 the ill-fated _Captain_ was lost. She was designed by Captain Coles and built by Messrs. Laird as a sea-going turret vessel. The principal armament was four 25-ton Armstrong guns carried in two turrets, one fore and one aft; these turrets were 27 feet diameter outside and 22¹⁄₂ feet inside, half the thickness of the wall consisting of iron plating. This ship behaved admirably on her trials and also on an experimental cruise, and was sent to sea with the fleet in September of that year. From some reason never explained satisfactorily she capsized without warning, and went down in a few seconds during a gale in the Bay of Biscay before daylight on the morning of September 7. Only nineteen of the 500 persons on board were saved, among the drowned being Captain Coles himself. This disaster evoked such an amount of criticism as to the vessel’s stability and seaworthiness that no more of the type were constructed, the turret ships subsequently built being modifications of the principle. [Illustration: _Photo. G. West & Son._ H.M.S. “LIGHTNING.”] [Illustration: _Photo. G. West & Son._ H.M.S. “TARTAR,” TORPEDO BOAT.]