A piece of iron plate sin. thick was subjected to a strain in the hydraulic press, and its breaking strain was found to be about 65 tons to the foot breadth of the plate. Riveted plates were afterwards sub jected to strain in the same machine, each rivet being sin. in diameter, and the rivets were in each plate varied in position. We give the following as illustrations ; the whole particulars of each experiment may be seen in the surveyor's report, as published in full in the Transactions of the Institute of Naval Architects in 1860' :— If we now turn our attention to the arsenals of war, a like series of novelties in steam-shipping awaits us. The question of iron armour for our wooden ships, for ships built entirely of iron, or built partly of iron and partly of wood, or of iron entirely with heavy plate armour, is at the present time an exciting subject. Under the presidency of Sir John Pakington, the Institute of Naval Architects has already con sidered the question of a screw fleet with advantage ; and the veteran Sir Howard Douglas, the Earl of Hardwicke, Captain E. P. Halsted, R.N., &c., have entered upon the subject with characteristic earnest ness and professional zeal. To detail what is doing would be premature. It is enough to say that the question of was never one of such importance to England as at present. 3luela might be said of an experiment made by France in building ships coated with heavy armour, like La Gloirc. Opinions, however, are so conflicting on various vital points, that, having touched briefly the prominent out lines of the subject, it must be left to the future to chronicle the ultimate success or failure of such experiments.
Two noble vessels called the Warrior and the Black Prince, the one built recently on the Thames and the, other on the Clyde, will bear prominently on the future history of steam shipping; a brief descrip tion, therefore, of one of these will be interesting, and the more so as a sort of rivalry between ourselves and another country exists in the question which is likely to influence very materially the nature of future naval warfare.
And first, the La Gloire is a fine wooden ship, having a length of 252 feet between perpendiculars, her breadth is 55 feet, and her draft at load water 271 feet. She is steamer-rigged, having square sails only on her foremast. Her masts arc small in proportion to the hulL It is supposed that her ports are only between 6 and 7 feet above water, in consequence of the weight of her defensive armour, which consists of plates of iron about 2 feet wide and 4i inches thick, extending from stem to stern, and for a distance below water. Her horse-power is supposed to be 900, with screw propeller, and she carries 34 fifty-four pounders on her main deck, and 2 screened heavy shell guns forward. Her ports are I14 feet apart on the main deck, a formidable arrange. ment as compared with every ship that preceded her. But the Warrior is a greatly superior ship, as the following dimensions will prove. (The Black Prince is of the same size and build as the Warrior.) The length of the Warrior is 350 feet between perpendiculars (420 feet over all), she is of 58 feet beam, 41i feet depth from spar-deck to keel, 26 feet draft of water, and of the burden of 6177 tons, builder's measurement ; fitted with screw propeller, and her engines, constructed by Penn and Sons, are of 1250 horse-power. She is built of iron, but her great peculiarity is that 205 feet of her length is protected by 4} inch plates of solid iron, backed with two layers of teak timber, one of 10 inches next the armour, and another within that of 8 inches. Her
armour extends to 9 feet below load-water line ; and at the extremities of the armour-clad portion of her hull, and quite across the ends of the ship at those parts, iron bulkheads of strength equal to the sides (being 4i-inch iron backed with 18 inches teak timber), protect the engines and stores from shots which might enter obliquely from head or stern ; and this inclosed space is divided into six water-tight com partments, her two boilers being each in its own separate compartment. In addition to this arrangement inner bulkheads extend all round the protected portion of her hull, leaving passages 36 feet wide, so that any leakage-water runs below, and this affords room for necessary repairs if injured by shot, &c. Her main deck.ports are about 8! feet above water (at load-water line), while her ports are 15& feet apart ; thus ample space is given for working her guns, and for warlike opera tions. With the spars and sails of an 80-gun ship (but barque-rigged, having no crossjack yard), she will be immensely superior to the La Gloire.
The Warrior is nominally a 36-gun ship, but her guns will be 68-pounders, 95 cwt., for the 'main deck, 10 Armstrong (70-pounders) on the spar-deck, and 2 pivot 100-pounders (Armstrong's also), one at each end—in all 48 guns; and the number can easily be increased.
As a comparison, the Warrior's superiority to the La Gloire may be thus briefly stated :—' Ports much higher out of the water, therefore could fight her guns in bad weather when La Gloire could not open her ports.
Her deck is much higher, to facilitate boarding.
has more space in which to work her guns.
Draws 18 inches less water than La Gloire.
Is leas dependent on steam, being nearly full rigged.
Has greater speed, perhaps of 2 knots per hour.
Has heavier armament.
Besides having very superior accommodation for her officers and Crew.
In closing this important detail it should be remarked, that early in 1859 Sir John Pakington, the first lord of the Admiralty, invited the naval architects from the coast to furnish plans for a mail-clad ship, and although numerous plans were forwarded (from Mr. Scott Russell, Mr. Samuda. Mr. Laird, Mr. Napier, &c.), the design adopted originated entirely in the office of the late Controller of the Navy, Sir Baldwin Walker, it being conceived by the Admiralty that such design con tained the average proportions and qualifications of all the others.
The last suggestion as to steam vessels for vi;ar purposes is that by Captain Cowper P. Coke, RN., who proposes certain sloping armour plates which shall throw off shot ; and also certain modifications in the mode of arming men-of-war so constructed; inasmuch as he would have only one row of .guns on the upper deck placed amidships, but placed on revolving, powerfully screened platforms. His highly in genious proposals have already been well received by the Admiralty, and experiments on a ship fitted by him have been ordered, and will probably commence in a few months.
The following outline sketches, drawn accurately to a scale of 240 feet to an inch, give an illustration of the relative sizes of the Great Eastern, H. M. S. Duke of Wellington, the Warrior, La (Noire, the llimalaya, and the Great Britain, some of the most noted among English steam vessels.