272 



SCIENCE OF HOME AND COMMUNITY 



vent skidding, the outer casing is made with a roughened 

 surface, and in wet weather chains are attached to the tires. 

 To reduce friction, the wheels are mounted on the axles by 

 means of antifriction ball or roller bearings. 



Frame and springs. The frame supports most of the 

 weight of the car, connects the axles, and carries the springs. 

 The frame is usually made of steel; and the lightness and 

 strength of the modern automobile are due largely to the 

 new varieties of steel that have been introduced in recent 



WriveAxte 

 ~* Bearing Mousing 

 ^Doub/e RowBearing 



FIG. 101. Semi-floating automobile rear axle construction with shafts and gear- 

 ing mounted on double row ball bearings. 



years. The frame is supported on the axles by means of 

 springs. 



Body. A number of types of bodies are made, according 

 to their use. The following are among the most common : 

 the roadster, coupe*, touring, limousine, and truck. These 

 may be made of either wood or metal. In order to reduce 

 the air resistance, which is especially noticeable at high 

 speeds, some bodies are made in a torpedo shape with 

 gradual curves and unbroken sides. These bodies are of 

 either the closed, open, or semi-closed type. Nearly all 

 types have a transparent wind shield to protect the operator 

 from dust and cold wind. Either celluloid or glass is used 

 for this shield. 



