[Illustration: Photo by Bain News Service.
In the latter part of the nineteenth century the French Government, which for so many years had shown a strong and continuous interest in the submarine problem, was particularly active. Three different types of boats built in this period under the auspices and with the assistance of the French Government deserve particular attention. The first of these was the _Gymnote_, planned originally by a well-known French engineer, Dupuy de Lome, whose alert mind also planned an airship and made him a figure in the history of our Panama Canal. He died, however, before his project could be executed. M. Gustave Zédé, a marine engineer and his friend, continued his work after modifying some of his plans. The French Minister of Marine of this period, Admiral Aube who had long been strongly interested in submarines, immediately accepted M. Zédé's design and ordered the boat to be built. As the earliest of successful submarines she merits description:
The _Gymnote_ was built of steel in the shape of a cigar. She was 59 feet long, 5 feet 9 inches beam, and 6 feet in diameter, just deep enough to allow a man to stand upright in the interior. The motive power was originally an electro-motor of 55 horse-power, driven from 564 accumulators. It was of extraordinary lightness, weighing only 4410 pounds, and drove the screw at the rate of two thousand revolutions a minute, giving a speed of six knots an hour, its radius of action at this speed being thirty-five miles.
Immersion was accomplished by the introduction of water into three reservoirs, placed one forward, one aft, and one centre. The water was expelled either by means of compressed air or by a rotary pump worked by an electro-motor. Two horizontal rudders steered the boat in the vertical plane and an ordinary rudder steered in the horizontal.
The _Gymnote_ had her first trial on September 4, 1888, and the Paris _Temps_ described the result in the following enthusiastic language:
She steered like a fish both as regards direction and depth; she mastered the desired depth with ease and exactness; at full power she attained the anticipated speed of from nine to ten knots; the lighting was excellent, there was no difficulty about heating. It was a strange sight to see the vessel skimming along the top of the water, suddenly give a downward plunge with its snout, and disappear with a shark-like wriggle of its stern, only to come up again at a distance out and in an unlooked-for direction. A few small matters connected with the accumulators had to be seen to, but they did not take a month.