THE TURBINE ENGINE 257 



ducing the speed so that, through gearing and heUcal spur 

 gears, the speed may be made as low as fift}^ revohitions a 

 minute. A more highly developed form of turbine is after the 

 plan of the reciprocating engine in the use of the steam, 

 several wheels being fixed upon a shaft and each using the 

 steam, one after the other, until its force has been exhausted. 



The advantages of the turbine engine over the recipro- 

 cating engine are manifold. Its construction is much sim- 

 pler and cheaper. The steam is applied to the turbine 

 directly, without the use of mechanism that involves friction, 

 lost motion, or expense through wear. It has no dead center 

 and will start from a. position. All parts are rotating, per- 

 mitting the highest speed. The condensing of steam in the 

 engine does it no harm as in reciprocating engines. It is 

 cheaper to buy than the steam engine of the other type, and 

 much cheaper to maintain. 



There are as many forms of turbine as there are forms 

 of the reciprocating engine, but, as with the latter, all work on 

 the same principle, and few have any advantage that the others 

 have not. They are becoming more widely introduced every 

 year and already are installed in several ocean liners, where 

 they are declared to have given entire satisfaction. 



The phenomenon of cavitation is one of the discoveries, 

 and perhaps the most interesting, that has resulted from the 

 installation of turbine engines into steamboats. The discov- 

 ery places a practical limit upon the speed of propellers on 

 ocean going steamers. The Parsons turbine on the Turbinia 

 developed such a speed that instead of exerting a pushing 

 influence upon the water it tended to create a vacuum after a 

 certain number of revolutions per minute had been made. 

 With this style of turbine, however, the Turbinia succeeded 

 in making a mile in 104 seconds in April, 1897, after a trial 

 trip in which the mile was finished in 110 seconds. 



A type of turbine engine that has for its motive power 

 water instead of steam, has been used with great success in 

 many parts of the country where the water supply furnishes 

 power for such machinery. In the vicinity of Niagara falls 

 and along the river above the falls hundreds of factories re- 

 ceive their power from water turbines placed in the stream, or 

 Vol. 7— ir 



