After Fulton’s death spasmodic attempts were made by various inventors looking to the solving of the difficult problem, but no very serious efforts were put forth until the period of the Civil War, and then a number of submarine boats were built by the Confederates. These boats were commonly called “Davids,” and it was one of them that sank the United States steamship “Housatonic” in Charleston Harbor on the night of the 17th of February, 1864. This submarine vessel drowned four different crews, a total of thirty men, during her brief career. At the time she sank the “Housatonic” her attack was anticipated, and sharp lookout was kept at all times; but, notwithstanding their vigilance, she succeeded in getting sufficiently close to plant a torpedo on the end of a spar, and sink this fine, new ship of 1400 tons displacement. It will be seen from the above description that these vessels, while able to go under water, were not controllable. After the Civil War several other inventors took up the problem of trying to design a submarine vessel that could be controlled as to maintenance of depth and direction under water. In Europe, Gustave Zede, Goubet and Drzwiezki, and in this country Mr. Baker and Mr. John P. Holland, built experimental vessels. In 1877 Mr. Holland built a small boat which was called the “Fenian Ram.” It is stated that this vessel was built with capital furnished by the “Clan-na-Gael,” with the idea of using it against the British fleet in an attempt to free Ireland. While some slight success was met with by these inventors, it was not until about 1897 that any real progress was made. ~THE FIRST SUCCESSFUL SUBMARINE WITH HYDROPLANES~ In 1893, Simon Lake, an American inventor, submitted plans to the United States Naval authorities at Washington for a submarine boat that would navigate between the surface and the bottom by the use of what he called “hydroplanes,” which were designed to cause the vessel to submerge on an even keel. Mr. Lake’s design of vessel was also provided with wheels to enable it to navigate on the water bed. It was also provided with a diving compartment to enable the crew to don diving suits and leave the vessel, in working on wrecks, cutting cables, planting mines, etc. In 1904 and 1905 he built a small vessel to demonstrate his principles and succeeded in successfully navigating the vessel on the bottom of New York Bay. He then built a larger vessel of about 50 tons displacement for further experimental purposes. This vessel was called the “Argonaut,” and was built in Baltimore in 1906 and 1907. This boat was successful from the start and covered thousands of miles in the Chesapeake Bay and along the Atlantic Coast, New York Bay and Long Island Sound, and was the first successful submarine boat to navigate in the open sea and on the water bed of the ocean.