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Now it must be quite clear, that if a shot be fired point-blank at a ship’s hull constructed with vertical sides, as h h, it would have the most favourable circumstances for penetration. But if the sides were of the section above water d, fig. 1, and below water b, a point-blank shot propelled parallel to the surface of the water would not pierce, but glance off from the surface of the armour-plates, j j, and the only mode in which they could strike the upper plates point-blank, would be by firing at a high elevation, with simply a falling force proportioned to the weight of the shot. And the lower plates below the surface of the water could scarcely be struck at all. And the practical strength of the plates at point-blank is one-third greater than if placed vertical. In other words, one plate 3 inches thick, at an angle of 45 degrees to the propelled shot will offer as great resistance as a plate of 4 inches and a-half in thickness at an angle of 90 degrees, independently of the glancing effect. I alluded to this in a former paper about a year ago. Three-inch plates would be better even, and cheaper than four-and-a-half.

In building a war-vessel in the present day, a wooden hull is an anomaly. The fact of breaching the vertical sides of iron ships an inch thick with round shot, on experimental trial, does not prove any deficiency in iron ships, but only ignorance in constructing them. With armour-plates stretching 8 feet above and 8 feet below the water line, at an angle of 45 degrees, it would be a very difficult thing to pierce them, and the experiment is worth trying, finding out at the same time whether the rifle or smooth bore is preferable. The breadth of beam and the length of vessel, as regards displacement, is simply a question of the load to be carried.

In a vessel constructed on this principle, it is obvious that the armour-plates should be bent at an angle to ensure strength, the length of the plate being up and down, and this form would facilitate the fixture of the plates with much lighter fastenings. But, inasmuch as the topsides or bulwarks incline inwards all round the deck to a height of 8 feet, a very large tank would be formed, tending to capsize the vessel in case of a wave breaking over her. Therefore a sufficient number of these plates should be hinged at or below the water line, allowing them to fall outwards with the pressure of the water, and so discharge it.

In regard to the question of guns, the usual mode is, to allow them to recoil and run in and out from a wide open port. From the recoil and breaking away of the gun, and from the missiles entering in at the port, an enormous loss of life ensues.

To diminish this waste of life, the first essential is, to use non-recoiling guns; and, secondly, breech-loaders. There is only one principle of preventing recoil, and that is, making the gun either by its own weight, or by its weight and that of the carriage combined, very far in excess of the weight of the shot. In a service-gun, weight 95 cwt., the 68-lb. shot is about 1 to 157, and this does not prevent recoil: diameter of bore, 8 inches; length of bore, 15 diameters.

At the diagram fig. 1, illustrating the section of a vessel’s hull formed to elude the force of shot, is a breech-loading gun A, exaggerated in apparent size, compared with the vessel. This gun is of 10-inch bore, and about 50 diameters in length. The weight of the gun is 50 tons, and the weight of the shot 3 cwt., or five times that of the 68-pound shot. There are no trunnions, but the muzzle is formed into a sphere or ball (k), which revolves in a socket formed in the iron topside of the vessel, entirely closing the opening, save a channel cut through the upper part of the ball for the purpose of sighting. The muzzle, therefore, would act as a port sufficing to keep out water, and in rolling, by the action of the

