America led the way during the Civil War blockades in 1864, when the _Housatonic_ was sunk in Charleston harbour, and damage done to other ships. But these experimental torpedo-boats were clumsy contrivances compared with their modern successors, for they could only carry their destructive weapon at the end of a spar projecting from the bows--to be exploded upon contact with the obstacle, and probably involve the aggressor in a common ruin. So nothing more was done till the perfecting of the Whitehead torpedo (see Dirigible Torpedoes) gave the required impetus to fresh enterprise. France, experimenting in the same direction, produced in 1889 Goubet’s submarine, patent of a private inventor, who has also been patronised by other navies. These are very small boats, the first, 16-1/2 feet long, carrying a crew of two or three men. _Goubet No. 2_, built in 1899, is 26-1/4 feet long, composed of several layers of gun-metal united by strong screw-bolts, and so able to resist very great pressure. They are egg-or spindle-shaped, supplied with compressed air, able to sink and rise by rearrangement of water-ballast. Reservoirs in the hull are gradually filled for submersion with water, which is easily expelled when it is desired to rise again. If this system goes wrong a false keel of thirty-six hundredweight can be detached and the boat springs up to the surface. The propulsive force is electricity, which works the driving-screw at the rear, and the automobile torpedo is discharged from its tube by compressed air. “By the aid of an optical tube, which a pneumatic telescopic apparatus enables the operator to thrust above the surface and pull down in a moment, the captain of the _Goubet_ can, when near the surface, see what is going on all round him. This telescope has a system of prisms and lenses which cause the image of the sea-surface to be deflected down to the eye of the observer below. “Fresh air for the crew is provided by reservoirs of oxygen, and accumulations of foul air can be expelled by means of a small pump. Enough fresh air can be compressed into the reservoirs to last the crew for a week or more.” The _Gymnote_, laid down in 1898, is more than double the size of the _Goubet_; it is cigar-shaped, 29 feet long by 6 feet diameter, with a displacement of thirty tons. The motive power is also electricity stored in accumulators for use during submersion, and the speed expected--but not realised--was to be ten knots.