Other submarines were built and experimented with, not only in the United States but in European countries. One of the later inventors was an Irish-American named John P. Holland, who, in 1876, built a submarine called the “Fenian Ram.” The “Ram” collapsed with the collapse of the Fenian movement. Other boats were built and tried, but the successful period of the submarine was deferred until after 1893, when the United States Congress appropriated $200,000 to encourage such an enterprise and invited inventors to submit designs. This, and a similar movement in France, formed the first official recognition of the value of vessels of this class. The prize offered by Congress brought out three designs, one by Mr. Holland, the “Ram” inventor, one by George C. Barker, and a third by Simon Lake. The names of Holland and Lake have since been closely associated with the history of the submarine. Mr. Holland’s device secured approval and in 1894 he received a contract to build a submarine vessel. This, named the “Plunger,” was begun in 1895, but was finally abandoned and a vessel of different type, the “Holland,” was built in its place. It was accepted by the government in 1900. A number of others similar to the “Holland” were subsequently built. The American Types. The type of these vessels was what became known as the “diving.” They were controlled by a rudder placed at the stern of the vessel and acting in both a horizontal and a vertical direction, the force of the screw propeller driving the boat forward in the direction desired. In 1904 the navy of the United States possessed eight Holland boats and there were also a number of them in the British navy. Mr. Lake’s design, offered in 1893 but not accepted, had as its novel feature a plan by which a door could be opened in the bottom of the ship and the crew leave and enter it in diving suits, the water being kept out by the force of compressed air. To maintain the vessel on an even keel he introduced four vanes, called “hydroplanes,” for regulating the depth of descent. By aid of these and the horizontal rudder it was found that the vessel would run for hours at a constant depth and on a level keel. There were other devices for diving or rising to the surface. In 1901 Mr. Lake built a large vessel of this type which was sold to the Russian government and was in commission at Vladivostock during the Russian-Japanese War. He afterwards received orders from this and other governments for a number of vessels of the even-keel type, and his principles of control have since been generally adopted as the safest and most reliable controlling agency for under-water craft.