Mr. Holland had, in 1894, received a contract for a submarine vessel for the United States Navy, and her construction was started in 1895. This vessel was called the “Plunger.” This was the first official recognition given to a submarine boat in the United States. The Government of France had also given an order for a submarine boat which was under construction at this period. The “Plunger” was never submerged, her construction covering a period of several years, and she was finally abandoned. Mr. Holland had, however, in the meantime prepared the designs of another vessel which he called “The Holland.” This vessel was accepted by the United States Government in 1900, and a number of other vessels of this type were built. These vessels were known as submarines of the diving type. They were controlled by means of a horizontal and vertical rudder placed at the stern of the vessel and the boat was, by means of these rudders, inclined down by the bow, and driven under the water by the force of their screw propeller. England also built a number of submarines of the diving type. In 1901 Mr. Lake brought out a larger vessel of his type, which was controlled by hydroplanes, which vessel was sold to the Russian Government, was shipped across the Atlantic to Kronstadt, and from there by rail to Vladivostok, and was in commission off Vladivostok just before the close of the Russian-Japanese War. Mr. Lake then received orders from the Russian and other Governments for a number of additional boats of the even keel type, to be controlled by hydroplanes. Mr. Lake’s principles of control have been now generally adopted by all Governments, as providing the safest and most reliable means of control of the vessel when navigating under the surface. The United States Government has recently adopted this type to be built in their Navy Yards, and most other builders have adopted the hydroplanes as the means of maintaining depth when running beneath the surface. [Illustration: CLEARING A CHANNEL OF BUOYANT MINES This is one of the services to which submarine boats of this type lend themselves with peculiar fitness. It is possible for them to carry on this work with deliberation and to success, under the very guns and searchlights of a vigilant foe, without the slightest danger of being detected.