“(1) Greatly increased speed, owing to diminution of weight and smaller steam consumption; (2) increased carrying power of vessel; (3) increased economy in coal consumption; (4) increased facilities for navigating shallow waters; (5) increased stability of vessel; (6) reduced weight of machinery; (7) reduced cost of attendance on machinery; (8) reduced size and weight of screw propellers and shafting; (9) absence of vibration; (10) lowered centre of gravity of machinery, and reduced risk in time of war. “The _Turbinia_ is 100 ft. in length, 9 ft. beam, 3 ft. draught amidships, and 44½ tons displacement. She has three screw shafts, each directly driven by a compound steam turbine of the parallel flow type. The three turbines are in series, and the steam is expanded—at full power—from a pressure of 170 pound absolute, at which it reaches the motor, to a pressure of one pound absolute, at which it is condensed. The shafts are slightly inclined, and each carries three crews, making nine in all. The screws have a diameter of 18 in., and when running at full speed they make 2,200 revolutions per minute. Steam is supplied from a water tube boiler, and the draught is forced by a fan, mounted on the prolongation of the low pressure motor shaft, the advantage of this arrangement being that the draught is increased as the demand for steam increases, and also that the power to drive the fan is obtained directly from the main engines. “Up to the present the maximum mean speed attained has been 32¾ knots, as the mean of two consecutive runs on the measured mile. These runs were made after about four hours’ steaming at other speeds, and the boat on the day of the trials had been fifteen days in the water. It is anticipated that on subsequent trials, after some alterations to the steam pipe, still higher mean speeds will be obtained. “It is believed that when boats of 200 feet in length and upward are fitted with compound turbine motors, speeds of 35 to 40 knots may be easily obtained in vessels of the destroyer class, and it is also believed that the turbine will—in a lesser degree—enable higher speeds to be realized in all classes of passenger vessels.” Referring to the difficulty of reversing the engines of the _Turbinia_, the _Scientific American_ adds, that “by using a system of ‘butterfly’ reversing steam valves, a motor has been constructed in which the steam may be made to flow through the blades of the turbine in either direction, the whole horse-power of the engines being thus available for going astern.” Detailed drawings and descriptions of the _Turbinia_ and the new motor may be found in the supplements of the _Scientific American_ (New York) for June 26th, 1897, and March 12th, 1898. INDEX. _Letter_ =“S”= _indicates Inland Steamer_, =“SS”= _Ocean Steamer._