GYBOSTATIG ACTION 



35 



boomerang, spinning in the direction of the arrows SS, Fig. 30, 

 tends to climb upwards through the air. The result is that the curve 

 of flight as shown in Fig. 30 is approximately a horizontal circle, the 

 drooping of the curve of flight which would normally be produced by 



■» \ 



+* 



^ 



.-~*r 



M 



Fig. 30. 



gravity being counteracted by the tendency of the boomerang to 

 glance upwards and the tendency of the boomerang to climb upwards 

 as specified. 



The Device of Otto Schlick foe the Prevention of Eolling of 



Ships at Sea 



Fig. 31 represents a spinning wheel hung upon a vertical axis from 

 a hinge which permits the axis to swing to and fro in the plane of 

 the keel of the ship (plane of paper in Fig. 31), the lower end of the 

 axle being guided between two parallel bars. If the spin-momentum 

 of the wheel were sufficiently great, all rolling motion of the ship could 

 be eliminated, and the ship would heel over into a position for which 

 the average heeling or rolling torque would be equal to zero; thus, the 



