WORKING WONDERS WITH A TOP 



what have you got to hang on to to hold her?' He 

 was right. You do have to have something to hang on 

 to.' And that something must be very powerful. 

 In the case of the stabilizing gyros it is the tremen- 

 dously augmented inertia of the rotating mass." 



It is apparent, then, that even with the Sperry 

 gyroscope it is necessary to use a revolving wheel of 

 rather formidable size. It appears, however, that con- 

 trary to what might be expected the power required 

 for control of the precession engine is trifling. This 

 is due to the fact that in rolling, as reflection will 

 show, the constant tendency of the ship is to do pre- 

 cession-wise work upon the gyro. Moreover the 

 weight of the gyroscope itself is by no means so great 

 as might be anticipated, inasmuch as the rotation 

 constitutes "a multiplier of tremendous magnitude, 

 even though the actual rotative speed is relatively 

 low." 



It has already been fairly demonstrated that the 

 Sperry gyroscope operates effectively when its mass 

 is but a fraction of the mass of water in the so-called 

 'damping tanks, which have hitherto been the most 

 practical means of minimizing the rolling of ships. It 

 is further estimated that the power required to oper- 

 ate the gyro even in bad weather is only a fraction of 

 the power wasted in propelling a ship provided with 

 bilge keels, which, as is well-known, have limited in- 

 fluence at best in preventing the ship from rolling. 



STABILIZING LAND VEHICLES 



The utility of stabilizing ships with the gyroscope 

 seems pretty clearly demonstrated. As to land ve- 



271 



