THE CONQUEST OF TIME AND SPACE 



whirl with it when pressed against the segment d or 

 Gs*, whereas the roller i^ 2 is fitted about anon-revolving 

 extension of the frame BACy and not to the spindle itself. 

 Bearing in mind that the gyroscope itself is perfectly 

 balanced and hence tends to maintain its axis O i^ in a 

 fixed direction, we shall be able to understand what must 



''S^i^s^' 



PIC.2. 



r t 



Fig. 2. 



happen when the car is tipped from any cause whatever 

 — as the shifting of its load, the pressure of the wind, or 

 the centrifugal action due to rounding a curve. 



Suppose, for example, that the car tips to the right. 

 This will bring the segment d in contact with the roller 

 Riy and the roller will instantly tend to run along it, as 



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