The North had a hand-power submarine, that was built at the Georgetown Navy Yard in 1862. It was designed by a Frenchman, whose name is now forgotten but who might have been a contemporary of Cornelius Van Drebel. Except that its hull was of steel instead of wood and greased leather, this first submarine of the United States navy was no better than an eel-boat of the seventeenth century. It was propelled by eight pairs of oars, with hinged blades that folded up like a book on the return stroke. The boat was thirty-five feet long and six in diameter, and was rowed by sixteen men. It was submerged by flooding ballast tanks. There was an oxygen tank and an apparatus for purifying the used air by blowing it over lime. A spar-torpedo was to be run out on rollers in the bow. Ten thousand dollars was paid to the inventor of this medieval leftover, and he prudently left the country before he could be called on to operate it, though he had been promised a reward of five thousand dollars for every Confederate ironclad he succeeded in blowing up. Like the first _Monitor_, this nameless submarine was lost in a storm off Cape Hatteras, while being towed by a steamer. After the loss of the _Housatonic_, the North built two semi-submersible steam torpedo-boats on the same idea as the _David_, but larger and faster. Both were armed with spar-torpedoes and fitted with ballast tanks to sink them very low in the water when they attacked. The smaller of the two, the _Stromboli_, could be submerged till only her pilot-house, smoke-stack, and one ventilator showed above the water. The other boat was called the _Spuyten Duyvil_. She could be sunk till her deck, which was covered with three inches of iron armor, was level with the water, but she bristled with masts, funnels, conning-towers, ventilators, and other excrescences that sprouted out of her hull at the most unexpected places. Neither of these craft was ever used in action. CHAPTER V THE WHITEHEAD TORPEDO How best to float a charge of explosives against the hull of an enemy’s ship and there explode it is the great problem of torpedo warfare. The spar-torpedo, that did such effective work in the Civil War, was little more than a can of gunpowder on the end of a stick. This stick or spar was mounted usually on the bow of a steam-launch, either partially submerged, like the _David_, or boldly running on the surface over log-booms and through a hail of bullets and grapeshot, as when Lieutenant Cushing sank the Confederate ironclad _Albemarle_. Once alongside, the spar-torpedo was run out to its full length, raised, depressed, and finally fired by pulling different ropes. So small was the chance of success and so great the danger to the launch’s crew that naval officers and inventors all the world over sought constantly for some surer and safer way.