handling it by two men, and that this would permit a bolt-formed projectile of as great a weight as 400 lbs. to be used, it would appear to be out of the question to attempt to construct ships absolutely, or, practically speaking, even generally impenetrable. The subject is a serious one, when it is considered that such projectiles might be fired against a vessel costing a sum approaching to half a million sterling by a tiny and swift gunboat. In 1854, during the Russian war, the subject of rifled mortars for throwing conical shot or shell of great weight was brought forward and strongly advocated by Lieutenant Palliser of the 60th Rifle Brigade, and in 1855 the writer saw one of his mortars tried by the Excellent at Portsmouth, with great success for a first experiment. It is also well known that at that time the Russians were turning their attention most seriously to the subject of mortar firing, with a view to meeting the floating batteries which were then being constructed in this country and in France, with their sides protected by 4-inch plates of iron, while their decks were left unprotected. In the event of a war, it is not likely that such means of destroying these vessels would be left untried, and certainly on our side many of the young officers commanding these small vessels, and anxious to distinguish themselves, even at a probable risk of their own destruction, would only be too eager to make the attempt. After completing the history, the theory of naval architecture was treated of by Mr Creuze, and the same arrangement has been continued. This portion of the present article has been rewritten, and is entirely the production of Mr Robinson, Headmaster of the school for apprentices in Chatham Dockyard. The writer believes that he could not have obtained the assistance of any one more competent to do justice to the subject, knowing that Mr Robinson's knowledge and acquirements in this respect have been highly considered by both Canon Moseley and Dr Woolley, the two highest authorities of the present day upon this branch of mathematical research. For the investigations respecting the effects of the forces which act upon a ship when in motion, and the strains to which she is liable under different circumstances, the writer is himself answerable, as well as for the portions upon the materials used in ship-building, upon the forms and the construction of the bodies of ships, and upon the practical operations required therein. On all these points, occasional remarks from Mr Creuze's previous work, which was placed by the proprietors at the disposal of the writer, have been introduced, but they are so mixed up with the general reasoning, that it was found impossible to separate them, or to give them entire as extracts from his work, without hurting the continuity of the argument, and rendering the illustrations aimed at obscure. The desire throughout has been to produce, in the simplest possible form, a work which may be useful to the practical ship-builders of this country. To naval officers, it is at the same time believed that much of the article will be found useful; because, while it must be beneficial to them to understand the principles on which the ships in which they are serving are constructed, they ought also, certainly, to understand those principles which regulate the strains to which their ships are exposed under different circumstances, and how these may be modified and lessened by their management. In conclusion, the writer desires to express his thanks to the managing Directors of the Peninsular and Oriental Company, and to the Practical Builders to whom he applied; and who, in the most kind and ready manner, furnished him with the valuable specimens of their works which appear in the plates. PORTSMOUTH, April 15, 1861. |