shaft, or, in other words, the engine shaft must push downwards on the bearing a and pull upwards on the bearing b, so that the gyrostatic reaction of the fly-wheel causes the outer wheels OO of the automobile to be pushed against the ground excessively as the automobile turns round a curve.

Figs. 11 and 12 represent the case in which the top of the spinning fly-wheel is moving forwards, and Figs. 13 and 14 represent the case in which the top of the spinning fly-wheel is moving backwards. In Figs. 13 and 14 the gyrostatic action of the fly-wheel causes the inner wheels II of the automobile to be forced against the ground excessively, as may be seen by studying the vector diagrams in Figs. 13 and 14.

Figs. 15 and 16 represent the case in which the fly-wheel shaft is parallel to the length of the car. In Fig. 15 the car is represented as turning to the right, the arrow S in the vector diagram represents the spin-momentum of the fly-wheel at a given instant, S' represents the spin-momentum at a later instant, ΔS represents the increment of spin-momentum, and T represents the torque which must act upon the fly-wheel shaft. To produce the torque T, the bearing a must push upwards upon the engine shaft and the bearing b must push downwards on the engine shaft, or, in other words, the engine shaft must push downwards on bearing a and upwards on bearing b. Therefore the