Submarine

in naval affairs, a boat fitted for service though entirely under water. The chief object sought is the carrying and projecting of torpedoes. The type of boat known as the Holland submarine, from the name of the inventor, has been adopted by several governments. This ship is cigarshaped. It is built of metal and glass and displaces about 122 tons of water. It is operated by an electrical 160-horse-power motor, and makes from eight to ten knots an hour. It carries three torpedo tubes and the largest size of torpedoes. This boat is capable of traveling along the surface like any other small ship. If occasion for action arises the crew goes down a hatchway, the trapdoor is shut water-tight, and enough water is admitted to tanks built for the purpose to sink the craft completely. Thick glass walls enable the engineer to see his way under water. Compressed air carried in chambers is released little by little, enabling the crew to remain beneath the surface for several hours.

The invention of submarines is a long story. As early as 1620, a Dutch inventor built a submarine of wood and covered it with oiled leather to make it water-tight. He gave James I of England a ride beneath the surface of the sea. The first American diving boat, the Turtle, 1775, was shaped like the animal for which it was named. Robert Fulton, whose name is linked with the first successful navigation of the Hudson river by a steamboat, invented a submarine which he called the Nautilus. French, English, German, Russian, and Swedish inventors have worked at the problem. Nordenfelt, an expert torpedo inventor, suggested valuable features. In 1894-7 Simon Lake designed a boat for peaceful purposes to be used in anchoring buoys, laying submarine foundations, and raising wrecks. It must be said, however, that the submarine is still in an experimental stage.