Early in the sixties, an Austrian artillery officer attached to the coast defenses conceived the idea of sending out the launch without a crew. He made some drawings of a big toy boat, to be driven by steam or hot air or even by clockwork, and steered from the shore by long ropes. As it would have no crew, this boat could carry the explosives in its hull, and the spars which were to project from it in all directions would carry no torpedoes themselves but would serve to explode the boat’s cargo of guncotton by firing a pistol into it, as soon as one of the spars came into contact with the target. Before he could carry out his ideas any further, this officer died and his plans were turned over to Captain Lupuis of the Austrian navy. Lupuis experimented diligently with surface torpedoes till 1864, but found that he would have to discover some better steering-device than ropes from the shore and some other motive-power than steam or clockwork. So he consulted with Mr. Whitehead, the English manager of a firm of engine manufacturers at the seaport of Fiume. Whitehead gave the torpedo a fish-shaped hull, so that it could run beneath instead of on the surface. For motive-power he used compressed air, which proved much superior to either steam or clockwork. And by improving its rudders, he enabled the little craft to keep its course without the aid of guide-ropes from the shore. The chief defect of the first Whitehead torpedoes, which were finished and tried in 1866, was that they kept bobbing to the surface, or else they would dive too deep and pass harmlessly under the target. To correct this defect, Whitehead invented by 1868 what he called the “balance chamber.” Then, as now, each torpedo was divided into a number of separate compartments or chambers, and in one of these the inventor placed a most ingenious device for keeping the torpedo at a uniform depth. The contents of the balance-chamber was Whitehead’s great secret, and it was not revealed to the public for twenty years.