Commerce is not the only peaceful mission of the submarine. In 1895 was organized an association known as the Lake Submarine Company, its purpose being to use the Lake type of submarine boat for the recovery of lost treasures from the sea bottom and for other possibilities of undersea work. This company is still in existence, its various purposes being to recover sunken ships and their cargoes, to build breakwaters and other submerged constructions, to aid in submarine tunnel building, to dredge for gold, to fish for pearls and sponges, and for similar operations. The first vessel adapted to these purposes was the "Argonaut," built by Simon Lake in 1894. The important feature of this boat was a diver's compartment, enabling divers to leave the vessel when submerged, for the purpose of operating on wrecks or performing other undersea duties. This vessel and its successors have bottom doors for the use of divers, as previously stated. They are now used for numerous purposes for which they are much better adapted then the old system of surface diving, the sea bottom being under direct observation and within immediate reach. This sea bottom, in localities near land, is abundantly sown with wrecks, old and new, and in many cases bearing permanently valuable cargoes, such as gold and coal. The Lake system greatly simplifies the work of search for sunken ships, the vessels being able in a few hours' time to search over regions which would have taken months in the old method. Many wrecks have been found by these bottom-prowling scouts and valuable material recovered. Thus vessels laden with coal have been traced that had been many years under the water and deeply covered with sand and silt, and their cargoes brought to the surface.

The gold-dredging spoken of refers to the working of gold-bearing sands found at the mouth of certain rivers in Alaska and South America. Places on the Alaskan coast, laid bare at high tide, are said to have yielded as much as $12,000 per cubic yard. With the Lake system it is possible to gather material from such localities to a depth of 150 or more feet, the material being drawn up by suction pumps into the vessel and its gold recovered.

Another important application is that of fishing for pearl shells, sponges and coral. This is blind work when done by divers from the surface, the returns being largely matters of chance. By aid of submerged boats, with their powerful electric lights, the work becomes one of certainty rather than of chance. The recovery of the oyster, clam and other edible shell-fish is also a feature of the work which the Lake Company has in view. The present method of dredging is of the "hit or miss" character, while the submarine method is capable of thorough work. Vessels have been designed for this purpose with a capacity of gathering oysters from good ground at the rate of 5,000 bushels per hour. In regard to submarine engineering, of its many varieties, the Lake system is likely to be a highly useful aid and assistance.;

These particulars are given to show that the submarine vessel is not wholly an instrument of "frightfulness," as indicated by its use in war, but is capable of being made useful for many purposes in peace. Some of these have here been very briefly stated. With continued practice its utility will grow, and by its aid the sea bottom up to a certain depth may become as open to varied operations as is the land surface.

A Semi submersible Wrecking Apparatus

A Semi-submersible Wrecking Apparatus.