CH. IX CENTRIFUGAL FORCE 1 45 



tional to the squares of the velocities, the radius of 

 the curve being constant. 



For a curve of 50 feet radius these inclinations 

 will be as follows : — * 



At 7 miles an hour, 3 degrees, 45 minutes. 

 10 ,, ,, 7 •> 35 " 



15 .. .. l6 -- 42 



20 ,, ,, 28 ,, 06 ,, 



25 ,, „ 41 .- 2I 



It is obvious, that if the angle of the road cross- 

 wise is, for any given curve and speed, that which 

 is indicated by the above computation, the coach 

 will have exactly the same stability as if it were 

 going straight on a level, and for a curve of 50 feet 

 radius the elevations of the outer wheel are given 

 in the following table : — 



At 7 miles an hour, 3.8 inches. 

 10 ,, ,, 7.9 



15 -- .- 17-2 



20 ,, ,, 28.4 



25 ,, ,, 39.6 



These quantities are the natural sines of the 

 angles given above, the length of the axle, 5 feet, 

 being unity. 



Since the base of the coach is wide, unlike that of 

 a bicycle, the resultant line of the centrifugal force 

 and of the weight will fall within the base with very 



* In these computations, the centrifugal force is to the weight as 

 the tangent of the angle is to unity. 



10 



