GYROSTATIC ACTION 



2 5 



disk has received a slight backward component of velocity and every 

 particle in the lower half of the disk has received a slight forward com- 

 ponent of velocity. Therefore, during the short interval of time, 

 every particle of the upper half of the disk must have been gaining 

 velocity backwards and every particle in the lower half of the disk 

 must have been gaining velocity forwards, so that unbalanced forces 

 must have been pushing backwards on every particle in the upper half 

 of the disk and pulling forwards on every particle in the lower half of 

 the disk, or, in other words, a torque must have been acting about the 

 line EE' as an axis as shown by the two arrows FF in the side view. 



Gyrostatic Action of the Fly-wheel of the Automobile Engine 



Figs. 11 and 12 show top views of an automobile, the curved dotted 

 arrows represent the turning of the automobile around a curve, and the 



^ 



f 



Fig. 13. 



Fig. 14. 



straight arrows 8 represent the spin of the fly-wheel shaft. The arrow 

 8 in the vector diagram of Fig. 11 or 12 represents the spin-momentum 

 of the fly-wheel at a given instant, the arrow 8' represents the spin- 

 momentum at a later instant, AS represents the increment of spin- 

 momentum, and the arrow T represents the torque which must act 

 upon the fly-wheel shaft. 



To produce this torque the bearing a must push upwards on the 

 engine shaft and the bearing b must push downwards on the engine 



