Although the Admiralty adopted iron ships, it did not finally abandon its old wooden ships until 1874--or a year after that in which the first steel vessel was built for the Navy--in which year the British Navy was enriched by the addition of the wooden corvettes _Sapphire_ and _Diamond_. Iron screw-driven cruisers or corvettes were the successors of the smaller fast wooden vessels, and a number of fast unarmoured ships of various types were built. One of them, the _Bacchante_, had the honour of being selected for the cruise round the world of the present King, when he and his brother, the late Prince Albert Victor, joined the Navy as midshipmen. The Americans claim that these types of vessels were introduced by the _Wampanoag_, which was designed at the time of the American Civil War to chase Confederate commerce destroyers. The extraordinary reports published in the sensation-loving American papers, and duly copied and accepted as true by the British papers, as to the speed and capabilities of this vessel and others of her class, in 1866, induced the British Government to decide on something similar, and, if possible, superior, and the _Inconstant_ was the result. She was 333 feet in length by 50 feet beam, and had a displacement of 5,782 tons on a draught of 23 feet. She was built of iron sheathed with wood and coppered, this arrangement enabling a light hull to be constructed which should take the strain of the machinery without being subject to the same “working” as a wooden ship would have had to endure on account of the greater elasticity of the material. The wood sheathing protected the iron, and also enabled the bottom to be covered with copper, or “yellow metal” as the composition was called which was generally used for the purpose, in order to prevent barnacles, weeds, and other marine growths from accumulating upon the submerged portion of the hull and retarding the speed. Considering that barnacles and weeds will grow thus to a length of several inches, the extent to which the speed of a vessel will be hindered may be imagined. All unsheathed vessels, whether of wood or iron, were peculiarly liable to these growths, which are particularly luxuriant in tropical waters, and might have their speed reduced even as much as from ten knots to six knots. The difficulty was to enable an iron ship to carry a skin of copper or yellow metal, the latter being mostly used in the mercantile marine, and the former for ships of war, private owners with their own money to spend being usually more economical than governments with the taxpayers’ money behind them, and not hampered by the problems of making the ships pay commercially. The _Inconstant_ was launched in November, 1868, and was followed in 1873 by the _Shah_, whose famous encounter with the _Huascar_ was alluded to in the previous chapter.