“The determination of the French Government to build a number of iron or steel-cased ships imperatively obliges us to follow their example. The original idea of plating ships in this way, so as to render them shot-proof, is due, not, as is generally supposed in this country, to the present Emperor, but to a Captain in the French Navy, who, about a quarter of a century since, suggested that all wooden vessels should be sheathed with composite slabs of iron of fourteen or fifteen centimetres in thickness; that is to say, with stout plates of wrought-iron having blocks of cast metal between. A similar suggestion was made among others by General Paixhans; but one of the first to reduce it to practice was Mr. Stevens, of New York, the well-known steamship builder, who about ten years ago communicated to Mr. Scott Russell the results of a long series of experiments, instituted by the American Government, for the purpose of testing the power of plates of iron and steel to resist cannon-shot. Mr. Lloyd, of the Admiralty, proposed the adoption of plates 4ins. in thickness, instead of a number of thinner sheets, as recommended by the Emperor. The English and French floating batteries were, as is well known, protected upon Mr. Lloyd’s plan. From trials recently made, however, it has been pretty well ascertained that this iron planking, on whatever principle applied, will only repel hollow shot or shells; heavy solid projectiles of wrought iron, or those faced with steel, having been found, on repeated trials, to perforate the thickest covering which has ever been adopted, and that, too, even at considerable ranges. “Mr. Reed,[88] already alluded to, proposes to protect only the midship portion of the ship, and to separate it from the parts fore and aft by strong watertight compartments, so that, however much the extremities might suffer, the ship would still be safe and the crew below protected; but, as he himself admits, there would obviously be no defence against raking shot. “The French vessels last alluded to, follow the lines and dimensions of the _Napoleon_ (one of the best, if not the finest ship in their Navy); but they will only carry thirty or thirty-six guns, and the metal sheathing will be from ten to eleven centimetres (about 4¼ins.) in thickness. Two similar ships are to be commenced here forthwith; and as the First Lord of the Admiralty has prophetically warned us that they will be the most expensive ships ever constructed in this country, it is earnestly to be hoped that they may be found proportionately valuable, should their powers ever come to be tested; they will each cost from £126,000 to £130,000, or £4,200 per gun; the ordinary expense of a sailing man-of-war being about £1,000, and of a steamer from £1,800 to £2,000 per gun.”