Transportation Water and Air 



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planes, horizontal planes at the tail of the machine controlled by 

 the aviator. If the elevating planes are turned downward air 

 pressure on the lower surface tends to throw the tail up and thus 

 head the machine down. If the elevating 

 planes are turned upward the air pressure on 

 the top tends to drive the tail down and to 

 cause the head of the plane to lift. A vertical 

 rudder at the tail steers the machine. 



Airplane bodies are modeled after the body 

 of a bird. That is, they are heavier and larger 

 in the front and taper back to the tail. 



For driving power, gasoline motors are 

 used, sometimes several being employed. The 

 individual motors may be of six, eight, or 

 more cylinders. One type of rotary motor 

 consists of nine cylinders. 



For landing purposes, the ordinary airplane has a wheel rig- 

 ging. For landing and taking off on a snow surface in cold 

 regions, runners are sometimes used. For landing and taking off 

 from water, pontoons, or air-tight, boat-like floats, are used, 

 capable of supporting the full weight of the machine. When these 

 are used the machine is termed a hydro-airplane. 



Wright Aeronautical 

 Corporation. 



A POWERFUL 

 RADIAL MOTOR 



Such motors are used 



in Navy scout planes 



and in certain other 



airplanes. 



Keystone View Company. 



AN ALL-METAL PASSENGER MONOPLANE 



When the plane is in flight, the wheels are pulled up to reduce air resistance. 



