Nothing further was done until July 1798, when Bruix was Minister of Marine. Fulton renewed his proposition, and certain inquiries by scientists of repute were made at the instigation of Bruix. The report was distinctly favourable, but again there was disagreement as to terms. Fulton, impatient of delay, built the Nautilus. This little vessel, twenty feet long and five feet beam, was launched at Rouen in July 1800. On the trial trip the inventor and two companions made two dives in the boat, the time of submersion varying from eight minutes to seventeen minutes. Proceeding to Havre, Fulton made various improvements in the Nautilus, including the introduction of a screw propeller worked by hand, and the addition of wings placed horizontally in the bows for the purpose of ascending or descending. While at Havre the submarine remained below over an hour at a depth of fifteen feet with her crew and a lighted candle. On another occasion the Nautilus was submerged for six hours, air being supplied by means of a little tube projecting above the water.
For sailing on the surface the boat was fitted with a single jury-mast carrying a mainsail jib, which could be unshipped when submarine navigation was required. By admitting water she sank to the required depth, and was then propelled by the method already referred to. A glass dome, a compass, a pump for expelling the water when necessary, and a gauge for testing depth, which Fulton called a bathometer, constituted the ‘works.’ The torpedo was an apparatus made of copper filled with gunpowder, “arranged in such a manner that if it strikes a vessel or the vessel runs against it, the explosion will take place and the bottom of the vessel be blown in or so shattered as to ensure her destruction.”[[3]] The weapon was to be fixed to the bottom of the victim by means of a barbed point on the chain used for towing it.
Fulton approached Napoleon, who authorized Forfait, the latest Minister of Marine, to advance the sum of 10,000 francs for the purpose of perfecting the Nautilus. He also granted Fulton an interview. When, in the autumn of 1801, he expressed a wish to see the submarine, the vessel had been broken up. Here the matter ended, and the ingenious American turned his thoughts in the direction of steam navigation. The Nautilus was his one and only experiment in underwater craft.[[4]]
The first ship to be actually sunk during hostilities by submarine was the Federal 13–gun frigate Housatonic, of 1264 tons. She went down off Charleston on the 17th February, 1864, during the American Civil War, as the result of being attacked by a spar-torpedo carried by the Confederate submarine Hunley, so named after her designer, Captain Horace L. Hunley. Unfortunately the underwater boat was also a victim, and she carried with her her fourth crew to meet with death as a consequence of misadventure. On the first occasion the boat was swamped and eight men were drowned, on the second a similar disaster overtook her, with the loss of six of her crew, on the third she descended and failed to come up. Small wonder that the Hunley came to be known as ‘the Peripatetic Coffin.’
The shape of the Hunley was cylindrical. For’ard and aft were water ballast tanks operated by valves, and additional stability was given by a sort of false keel consisting of pieces of cast iron bolted inside so as to be easily detachable should it be necessary to reach the surface quickly. On each side of the propeller, worked by the hand-power of eight men, were two iron blades which could be moved so as to change the depth of the vessel. The pilot steered from a position near the fore hatchway.
The torpedo, a copper cylinder containing explosive and percussion and primer mechanism, was fired by triggers. It was carried on a boom, twenty-two feet long, attached to the bow. The speed was seldom more than four miles an hour on a calm day. As there was no means of replenishing the air other than by coming to the surface and lifting one of the hatchways, it was obviously a fair-weather ship.
On the afternoon of the 17th February, 1864, the Hunley set out on her final trip. While attacking the submarine was only partly submerged, and one of the hatches was uncovered; why will never be known. She made straight toward the Housatonic, with the evident intention of striking the vessel near the magazines with her torpedo. There was an explosion, the ship heeled to port, and went down by the stern. When divers examined the extent of her injuries the plucky little Hunley was found with her nose buried in the gaping wound in her victim’s hull. Her crew were dead, but apparently the officer was saved.
Other submarines or partly submersible boats were used by the defenders of the Southern cause. They were usually termed ‘Davids’ because they were built to sink the Goliaths of the Federal Navy. The New Ironsides, the Minnesota, and the Memphis were all damaged as a result of their operations.
The only weapon of the submerged submarine is the torpedo. The World War brought no surprise in this direction. For surface work the calibre of the guns mounted on the disappearing platforms has increased very considerably. In 1914 a 14–pdr. was considered ample armament. With added displacement, gun-power has grown enormously. Some German underwater craft in 1918 carried 5.9–in. guns—that is to say, weapons larger than those used by many destroyers.
During the past decade torpedoes and submarines have made almost parallel progress. Of the various types of the former, the Whitehead is first favourite in the Navies of Great Britain, Japan, Russia, and Austria-Hungary, while France uses both the Whitehead and the Schneider, and Germany was exclusively devoted to the Schwartzkopf (Blackhead). The extreme effective range of each may be taken as from 10,000 to 12,000 yards. The essential difference between a torpedo and the usual run of naval ammunition for guns is that the torpedo retains its propellant, while the shell does not. The torpedo is really an explosive submarine mine forced through the water at a rate varying from 28 knots to 42 knots by twin-screws worked by compressed air engines. Any deviation from the course is automatically corrected by a gyroscope. Some torpedoes are now fitted with an apparatus which causes the torpedo to go in circles should it miss its mark and meet with the wash of passing ships. There is the added possibility, therefore, that the weapon may strike a vessel at which it was not aimed when a squadron is proceeding in line ahead.