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air pumps Alecto amount angle appears Archimedes arrangement Basilisk breeze from N.E. calm canals cent centimetre constructed crank cylinders diagram diameter diminished disc Ditto dynamometer efficiency employed Ericsson exerted experiments Faint breeze four blades friction gearing given head winds High horse power hull immersed section inches increased indicator diagrams iron vessels July knots per hour length Light airs Light breeze means Medium Messrs metres midship section miles motion nautical miles Niger number of revolutions obtained paddle steamers paddle vessels paddle-wheel patent was taken Pelican Plate Pleasant breeze pressure propeller shaft propelling blades propelling vessels proportion proposed propulsion ratio Rattler result revolutions per minute revolving rudder sails screw engines screw propeller screw shaft Screw Steam screw vessels ship square feet square foot steam vessels steamer stern stroke Strong breeze surface thrust tons trial valves vanes velocity voyage wheels windmill
Page 97 - Face, is equal to the Weight of a. Column of the Fluid, whose Base is the Plane...
Page 85 - Before finally deciding, however, upon the adoption of the propeller, the Lords of the Admiralty considered it desirable that an experiment should be made with a vessel of at least 200 tons ; and Mr. Smith and the gentlemen associated with him in the enterprise, accordingly resolved to construct the Archimedes.
Page 16 - As the ends of the sails nearest the axis cannot move with the same velocity that the tips or farthest ends do, although the wind acts equally strong upon them, perhaps a better position than that of stretching them along the arms directly from the centre of motion, might be to have them set perpendicularly across the farther ends of the arms, and there adjusted lengthwise to the proper angle. For, in that case, both ends of the...
Page 14 - ... to revolve in the water without any cylinder surrounding it. This worm or screw may be made to revolve in the water at the head of the ship, boat, or other vessel, or at the stern, or one or more worms may revolve on each side of the vessel, as may most conveniently suit the peculiar navigation on which the ship, boat, or vessel is to be employed. In some cases when the screw is to work at the head of a ship, it is to be made buoyant, and move on a universal joint, at the end of an axle, turning...
Page 10 - A, may be introduced a wheel with inclined Fans, or Wings, similar to the fly of a smoke-jack, or the vertical sails of a windmill...
Page 14 - Treatise on Propelling Vessels by Steam, says, " Experiments have been made on a kind of screw, but this I believe, after a trial on a considerable scale in America, was rejected. Some mechanics, however, still think favorably of it, and suppose that if a screw of only one revolution were used, it would be better than where a longer thread is employed.
Page 85 - She was built under the persuasion that her performance would be considered satisfactory if a speed was attained of four or five knots an hour, and that in such an event the invention would be immediately adopted for the service of the navy. Nearly twice that speed was actually obtained. After various trials on the Thames and at Sheerness, the "Archimedes," on the 15th of May, 1839, proceeded to sea.
Page 22 - sort of screw or ' worm,' made to revolve rapidly under water in a recess or open space formed in that part of the after part of the vessel commonly called the dead rising or dead wood of the stern," ' was also at work with his invention, and, in the following year, put it into practical operation.
Page 86 - Archimedes" had accomplished the circumnavigation of Great Britain, she made a voyage to Oporto. This voyage was performed in sixty-eight and a half hours, and was at the time held to be the quickest on record. She also visited Antwerp and Amsterdam, passed through the North Holland Canal, and made a great number of trips to other places, leaving everywhere the impression that she had succeeded in demonstrating the practicability of propelling vessels by a screw in an efficient manner. She was next...
Page 84 - Smith and his friends constructed a boat of six tons burthen, and about six horse-power, to further demonstrate the advantages of the invention. This boat was fitted with a wooden screw of two turns. On the 1st of November, 1836, she was exhibited to the public in operation on the Paddington Canal, and continued to ply there and on the Thames until the month of September, 1837. During one of her trips on the Paddington Canal, in February, 1837, an accident occurred which first pointed out the advantage...