1920] 



on The Gyrostatic Compass 



29 



acting, producing a permanent twist in " azimuth " and a constant 

 error. It is therefore preferable to damp the swings of the compass 

 by acting upon the tilt rather than its movement in "azimuth," 

 because in this case there will be no latitude error. The tilt is a 

 maximum at the middle of each swing — that is, when it is moving 

 through the north position — and it is the return of the weight to its 

 truly vertical position that is responsible for the continuation of the 



Fig. 5. — "Brown" Gyro-Compass removed from Binnacle. 



oscillation. We therefore require some method of neutralising the 

 action of the weight, not before, but after the compass lias reached 

 the north. This I accomplish in the "Brown" Gyro-Compass by 

 automatically moving a liquid from one bottle to another, and in 

 such a direction as to counterbalance the weight, precessing the gyro 

 wheel ; and I delay its action by means of a valve or constriction in 

 the tube joining the two bottles (see Fig. 10). 



