The origin of the most prominent of the automobile torpedoes is due to Captain Lupuis of the Austrian navy, and its development from 1864 onward to Whitehead, an Englishman. It is a cigar-shaped submarine vessel from 14 to 19 inches maximum diameter and from 14 to 19 feet long, which is blown from a torpedo-tube or gun within the ship by compressed air or an impulse charge of gunpowder. Twin-screw engines contained within its hull, and driven by compressed air stored in a reservoir therein, drive it at about thirty knots speed through an effective range of 600 yards. In its nose or “war-head” there is carried a large charge of gun cotton or other high explosive, which is fired by contact with the enemy’s hull. It is provided with both horizontal and vertical rudders, the depth of immersion being regulated by intricate machinery contained in the “balance-chamber.” The Whitehead has a somewhat formidable rival in the United States in the torpedo invented by Rear Admiral Howell, U. S. N. The automobile torpedo has never yet scored in battle against ships in motion. Its position in the naval warfare of the future is yet unfixed. The one certainty is, that its blow when struck home is almost surely fatal to ship and crew. The development of the submarine torpedo-boat, whose weapon is the Whitehead, has in recent years received much attention through the labors of the American Holland and others. France, in the Gustavus Zede, of 260 tons, has a diving boat of this character, for which much is claimed. VIII. THE UNITED STATES FLEET. Until the advent of the ironclad, the ships of the United States were equal, if not superior, in seaworthiness and fighting qualities to any in the world. The high standard set by the Constitution and her class of 1797 was maintained for sixty years; and, especially during the period from 1840 to 1860, the officers and men of the United States navy trod the decks of the finest ships afloat. They felt—as their successors feel—that, ton for ton and gun for gun, they had no foe to fear. The early steamers of the Powhatan class built in the late 40’s were a credit to the nation; the five screw frigates of the Merrimac type (1856–57) aroused the admiration and imitation of foreign experts, and the five corvettes which followed them in 1858–59–60, of which the noble Hartford was the chief, bore their full share in the war which was so soon to come. The gallant Kearsarge was the leader of a new class introduced in 1859.