NAVTILIIS PROPELLER was long the best known among many names given to a mode of propelling steam-vessels by means of a horiAntal wheel within board, instead of a paddle or a screw on the outsiae. Trydraulie propeller has latterly come more into use. Engineers thought of this mode of propulsion generations ago. and patents have been taken out for inventions relating to it by Toogood, Hayes, Rumsey, Linaker, Hall, and others; but the most successful attempts to realize it have been those of Mr. Ruth yen. He constructed a small boat, 9 ft. long, in 1839 (tried on the Union canal), and a vessel, 40 ft. long, in 1844 (tried on the Forth), to test the principle; each was worked by a small steam-engine. Rini provided with the hydraulic apparatus. In 1849 Mr. Ruthvot made improvements in the apparatus, and introduced them in a vessel, 30 ft. long, tried upon the Thames. In 1851 he placed a boat in the great exhibition. In 1853 a vessel (Ai this principle, called the Albert, was built in Prussia by M. Sydel, the machinery being supplied by Mr. Ituthven., She plied on the Oder as a passenger-steamer for many.
rears, and illustrate' fivorably some of the characteristic features of the nautilus sys tem. The term of Mr. Huth \TICS patent expired, however, before the invention had worked its way into use in England; and the privy council, in 1/7:4:), gave a further term of ten years. Ile afterwards began building a vessel to be called the Xadfilml; while the admiralty authorized the commeneement of the gun-vessel 'Valet-witch, both to be worked on the lintliven principle.
The was find, tried on the Thames in April, 1806. It is titled with two steam engines, of 1.0 (uom.'nal) horse-power one, with cylinders of 17 in. diameter, and 2 ft. stroke. Water is admitted through apertures in the bottom of the vessel into a water tight iron case or compartment. In this ease is placed a horizontal so-calied turbine wimel, 7 ft. in diameter. acted on from a vertical shaft connmted with the steam-cylin drys. The wheel is divided iu:o compartments by plates or radii of peculiar curvature, and is placed below the water-line of the vessel, so as to be always immersed. Two
pipes extend to the wheel-case, one to either side of the vessel, whom the y emerge manly at min ship. . Each pipe terminates with nozzles, 10 in, in diameter, placed outside the vessel at right angles to the pipes; insomuch that each side of the vessel has a nozzle pointing ahead and another pointing astern. A valve is fitted to each pipe, at its june• lion with the nozzles, to open the passage to one nozzle and close it against the other; am: the movement loth of the starboard and the port valves can be governed fioni a raised deck built over the engine-house. The wheel-ease is always full, or nearly full, of water, which enters through the apertures in the bottom of the vessel. When the wheel is made to rotate horizontally by the steam-engines, water is drawn in through the hollow axis, and expelled at the periphery by centrifugal force; it can only find an outlet through the two pipes, and then through the nozzles which terminate them. Supposing the nozzles pointing astern to be open, and those pointing ahead to he closed, the vessel is propelled forward by the resistance of the water of the river or sea to that rushing out of the noe.zles; when the forward nozzles are open, and the hinder 1.11eS closed, the ves sel is propelled backward, or driven astern. The captain, standing on the raised deck, and both valves, can close the fore-nozzles, and open the aft, which makes the vessel go ahead; he can open the fore and close the aft, which makes her go astern; he can open one fore-nozzle, and close the other, which makes her turn. The exit of the water from the nozzles is a little above sea-level, a plan found to be better than actually immersing them. In one of the trial trips of the Nautilus. with strung wind and tide urging her on, and going at full speed, she was stopped dead in less than 10 seconds. and in about rt qual ter of her length. by simply reversing the valves.