TORPEDO BOAT. 360 TORPEDO NET. Fulton's experiments in France and America (1795-1812) demonstrated that a vessel could be built which could descend to any given depth and reascend at will. Plunging mechanism was devised about the middle of the eighteenth cen- tury, but Fulton developed the vertical and hori- zontal rudders and provided for the artificial supply of air. A form of periscope existed in 1692 and an improved kind was patented in 1774; in 1854 Davy still further developed it. Phil- lips's wooden boat on Lake Erie was crushed by the water pressure, and the same fate befell Bauer's iron boat Plonqcur-Marin (Fig. 1 on Plate) at Kiel in 1S50. In 1803 JlcClintock and Howgate built a semi-submarine hand-propelled boat for the attack on the Federal lleet, but it sank four times, each time drowning the entire crew of eight men. In the same year several larger boats propelled by engines were commenced in Europe, and these at intervals were followed by others designed bv Hovgaard, Goubet, Zede, Nordenfeldt, Tuck, Holland, etc. The French Navy began experimenting with submarine boats about 1885. The Gym note was built in 1888 and the (justave Zcdc in 1893. The Morse was com- menced in 1894, but remained uncompleted until 1899, pending additional experiments with the Gymnote and the Zcd^. In that year the con- struction of submarines was actively commenced, 10 being launched in 1901. In 1880 Nordenfeldt built two large submarines for Turkey, but little was ever done with them after they passed into Turkish hands. In 1889 Spain bu'ilt the Pcral, Portugal following with the Plomicur in 1892. Italy built the Dclfiuo in 1895. ' The United States had the submarine boat under considera- tion for several years. The first boat ordered (about 1895) was never completed, but seven of the Holland tj'pe were ordered in 1900 and one was purchased when nearly complete early in that }ear. Consult: Sleeman, Torpedoes and Torpedo War- fare (2d ed., Portsmouth, England, 1889); Del- peuch. La navigation sous-marine <i trovers les siccles (Paris, 1902) ; Burgoyne, Submarine Navigation (London and New York, 1903) ; Bu- chard, Torpillcs et torpilleurs (Paris, 1889) ; Proceedings of the United States Naval Institute, particularly No. 100, December, 1901 (Annapolis, current) . TORPEDO BOAT DESTROYER. See Tor- pedo Boat. TORPEDO DIRECTOR. An instrument de- signed to indicate the proper moment at which to fire a torpedo from a ship or torpedo boat. It is placed on deck, or in a port or air-port giv- ing a clear view of the enemy. The type shown in the sketch is for a bow torpedo tube on a tor- pedo boat; a broadside director differs chiefly in having a greater arc of train for the arm B. The instrument consists of a metal sector. A, graduated along the limb E into degrees of arc. On this are three movable arms, B, C, and D. B and D are pivoted on A at the centre of the arc E, while C pivots on the sliding block G. B and C are graduated into similar and equal divisions, representing the speed of the torpedo and the enemy respectively. The arm B is first set parallel to the axis of the torpedo tube, and the block G is set at the division of the scale. K, corresponding to the speed of the torpedo. The block H is set at the division of the scale Xi which corresponds to the estimated speed of the enemy, and the arm C is swiuig around until parallel to his supposed course. Then the clamp- screws M and N are screwed down. The direc- tion MN (or IJ) is therefore the direction in TORPEDO DIBECTOR. which the enemy must be in order to be hit by the torpedo moving in the direction MF, if the estimated speeds of enemy and torpedo are cor- rect. The moment that the enemy is on the proper bearing is ascertained by looking over the sights I and J. TORPEDO NET. A net made of heavy wire rings connected with one another by small steel rings and surrounding a vessel of war below water as a defense against torpedoes. The net is made up in sections about 15 by 20 feet in size, and these sections join to make the total pro- tection, which is divided into three parts called the 'main defense,' 'bow defense,' and 'stern de- fense.' All except the main defense are frequent- ly omitted, and it only can be carried if the vessel is moving slowly, while no nets are of any use if the ship is moving at fair speed. The type of net most in favor is that devised by Jlr. Bulli- vant, an Englishman in the employ of the Ad- miralty. The Bullivant net Is made of. wire rings or grommets (see Knotting and Splicing) six; inches in diameter connected to each other by galvanized steel rings. Each section weighs about 400 poimds and has a heavy piece of chain at the foot to keep it as nearly vertical as possible when the ship is under way or anchored in a current; the sections are joined to each other by stout wire lashings. The upper edge of the net has small rings sliding on a wire rope, called a jackstay, which is shackled to the outer ends of the booms. Each of the booms is of hollow steel tubing, and is about 30 feet long. The inner end is fitted with a ring which passes through .another ring at the upper end of a pivot bolt which works in a lug secured to the ship's side. The outer end is fitted with two topping lifts and two guys. The booms are placed about 45 feet apart. When not in use the booms are
