6 ANNUAL OF SCIENTIFIC DISCOVERY. 



NEW MARINE ENGINE. 



EXPERIMENTS have been made in New York, under the inspection 

 of Mr. C. H. Haslet, Engineer of the Navy, with a boat fitted with 

 a new engine, called the "pulley-engine." Two boats were con- 

 structed, each 50 feet long, and as nearly alike as possible, with 

 water-wheels of the same size, and boilers with cylinders of the same 

 bore. One of the engines was constructed upon the usual plan ; the 

 other upon a new plan, which is the invention of Mr. Yates, of Mil- 

 waukee. In all the experiments the Pulley (so called from its engine) 

 rapidly left the other (the Crank) behind ; and it would appear that, 

 with a cylinder of 48-inch stroke, the pulley-engine is capable of turn- 

 ing the same sized wheel as the crank-engine, faster than the crank 

 with two strokes of 32 inches each. The crank, therefore, using one 

 third more steam to each revolution than the pulley, the pulley is en- 

 titled to make one third more revolutions than the crank, to equal the 

 consumption of steam. The value of one third more revolutions to 

 the same amount of steam in the marine engine is an advantage, 

 which, if attainable, our engineers will not fail to appreciate. This 

 improvement is also believed to be superior for marine purposes, on 

 account of its constant and uniform leverage at every point of the rev- 

 olution, and its entire revolution at every stroke of the piston. New 

 York Tribune. 



APPARATUS FOR STOPPING STEAM-ENGINES. 



THE object of this invention is to enable the superintendent of ma- 

 chinery, situated at a distance from the steam-engine, to stop its action 

 and momentum instantaneously, without the necessity of communi- 

 cating with the engineer. For this purpose, the patentees, Messrs. 

 Donisthorpe and Milnes, propose to employ, in low-pressure engines, 

 a pipe, which opens into the condenser at the bottom, and communi- 

 cates with the atmosphere at the top. This pipe is opened and closed 

 by a cock, placed in the upper part of it, on the spindle of which there 

 is affixed a weighted lever. When the pipe is closed, and a vacuum 

 established in the condenser for working the engine, the weighted end 

 of the lever is supported in a horizontal line by a sliding plate, on 

 which the weight rests. The other end of the sliding plate is attached 

 to a bell-crank lever, to which v.ires are connected, \vhich are carried 

 into different apartments, where the machines are placed, and there 

 provided with pulls ; so that, to stop the engine, it is only necessary 

 to move the pull, which will cause the sliding plate to be withdrawn 

 from under the weighted end of the lever, which will then fall down 

 into a vertical position, open the condenser to the air, thus destroying 

 the vacuum and stopping the machine. In a high-pressure engine 

 some changes in the mode of application are necessary. Means are 

 adopted to prevent the engine from being wantonly stopped. Lon- 

 don Mining Journal, May 26. 



