_The Torpedo._--Whitehead’s success arose out of the failure of an enterprising Austrian officer, Captain Lupuis, who had been trying to steer a small fireship along the surface of the water by means of ropes from a fixed base either on shore or in a parent ship. The plan was a crude one and was rejected by the Austrian naval authorities; it was then entrusted to Whitehead, who found it incapable of any practical realisation. He was, however, impressed with Lupuis’ belief in the value of a weapon which could be operated from a distance, and though he failed in designing a controllable vessel, he conceived the idea of an automobile torpedo, and, after two years’ work, constructed it in a practical form. It has been spoken of as ‘the only invention that was perfect when devised,’ and it certainly came very near perfection at the first attempt, but it was erratic and could not be made to keep its depth. In 1868, however, Whitehead invented the ‘balance-chamber,’ which remedied these defects, and brought two finished torpedoes to England for trial. They were fired by compressed air from a submerged tube, and at once proved capable of averaging 7½ to 8½ knots up to 600 yards and of striking a ship under way up to 200 yards. The target, an old corvette in the Medway, was sunk on to the mud by the first shot, at 136 yards, and immediately after the trials the British Government bought the secret, and other rights. Imitations were, of course, soon attempted in other countries, and a type, called the Schwartzkopf, was for some years manufactured in Berlin and used in the German and Spanish navies; it was also tried by the Italians and Japanese, but it failed in the end to hold its own against the Whitehead. The automobile torpedo was at first used only for the armament of ordinary war-ships; it was not until 1879 that an American engineer named Mortensen designed a submarine with a torpedo-tube in the bows. His example was followed by Berkeley and Hotchkiss in 1880, by Garrett in his first Nordenfelt boat of 1881, and by Woodhouse and by Lagane in the same year. Even after this Drzewiecki, Tuck, and D’Allest designed their submarines without torpedo-tubes, but they were, in fact, indispensable, and the use of the Whitehead torpedo has been for the last twenty years assumed as the main function of all submarines designed for war.