THE MASTER WORKER 



ROTARY ENGINES 



All these improvements, it will be observed, have 

 to do with details that do not greatly modify the steam 

 engine from the original type. The cylinder with its 

 closely fitting piston, as introduced in the Newcomen 

 engine, is retained and constitutes the essential mechan- 

 ism through which the energy of steam is transferred 

 into mechanical energy. But from a comparatively 

 remote period the idea has prevailed that it might be 

 possible to utilize a different principle; that, in short, 

 if the steam instead of being made to press against a 

 piston were allowed to rush against fan-like blades, 

 adjusted to an axle, it might cause blades and axle to 

 revolve, precisely as a windmill is made to revolve by 

 the pressure of the wind, or the turbine wheel by the 

 pressure of water. 



In a word, it has been believed that a turbine engine 

 might be constructed, which would utilize the energy of 

 the steam as advantageously as it is utilized in the pis- 

 ton engine, and at the same time would communicate its 

 power as a direct rotation, instead of as a straight thrust 

 that must be translated into a rotary motion by means 

 of a crank or other mechanism. 



In point of fact, James Watt himself invented such 

 an engine, and patented it in 1782, though there is no 

 evidence that he ever constructed even a working model. 

 His patent specifications show "a piston in the form 

 of a closely-fitting radial arm, projecting from an axial 

 shaft in a cylinder. An abutment, arranged as a flap 

 is hinged near a recess in the side of the cylinder, and 



