CATALOGUE OF THE MECHANICAL ENGINEERING COLLECTION. 



45 



valve is of the drop type and is placed at the side of the cylinder. 

 Both valves are actuated by a shaft driven by gearing at one-half the 

 speed of the crank shaft. The speed of the engine is regulated by a 

 centrifugal governor which, when the normal speed is exceeded, pre- 

 vents the admission of gas so that no explosions take place until the 

 speed has fallen to the prescribed limit. The engine may be arranged 



PIG. 19. LAXGLEY AERODROME ENGINE, 1901. 



to be double-acting by providing the requisite valve gear for each 

 end of the cylinder. Cat. No. 251, 284 U.S.N.M. 



Five-cylinder Water-cooled Gasoline Motor. Made in the Smithsonian In- 

 stitution Shops by Charles M. Manly for the full-size Langley Aerodrome, 

 1901. 



This four-cycle engine has stationary cylinders arranged radially 

 on a central drum. They are made of seamless steel tubing, lined 

 with cast-iron liners one-sixteenth of an inch thick shrunk into them. 



