In view of all that has been said thus far and remains to be said concerning the submarine, it might be well to digress for a moment and devote the remainder of this chapter to a consideration of the undersea fighter, its genesis, what it now is, and what it has accomplished. We all know that the submarine was given to the world by an American inventor--that is to say, the submarine in very much the form that we know it to-day, the effective, practical submarine. The writer recalls witnessing experiments more than twenty years ago on the Holland submarine--the first modern submarine type--and he recalls how closely it was guarded in the early days of 1898, when it lay at Elizabethport and the Spanish war-ship _Viscaya_, Captain Eulate, lay in our harbor. This was a month or so after the destruction of the battleship _Maine_ in Havana Harbor, and threats against the Spanish had led, among other precautions, to an armed guard about the _Holland_ lest some excitable person take her out and do damage to the _Viscaya_. There was no real danger, of course, that this would happen; it merely tends to show the state of public mind. Well, in any event, the _Holland_, and improved undersea craft subsequently developed, converted the seemingly impossible into the actual. To an Englishman, William Bourne, a seaman-gunner must be credited the first concrete exposition of the possibilities of an undersea fighter. His book, "Inventions or Devices," published in 1578, contains a comprehensive description of the essential characteristics of the undersea boat as they are applied to-day. From the days of the sixteenth century on down through the years to the present time, submarine construction and navigation have passed through various stages of development. Captain Thomas A. Kearney, U.S.N., in an interesting monograph published through the United States Naval Institute at Annapolis, says that of the early American inventors, particular mention should be made of the work of David Bushnell and Robert Fulton, both of whom have been termed the "father of the submarine." Bushnell's boat, completed in 1775-6, was much in advance of anything in its class at the time. The boat, which was, of course, water-tight, was sufficiently commodious to contain the operator and a sufficient amount of air to support him for thirty minutes. Water was admitted into a tank for the purpose of descending and two brass force-pumps ejected the water when the operator wished to rise. Propulsion was by an oar astern, working as the propeller of a vessel works to-day. Practically Bushnell in one attempt to destroy a British war-ship in the Hudson River was able to get under the British frigate _Eagle_ without detection, but was unable to attach the mine which the boat carried.