SECT. 3] 



AlU'El CATIONS OF THE UVKOPENDULUM 



329 



effects of horizontal accelerations and to avoid the jDroblem of correcting 

 angular misalignment between the master gyro and a remote observing station 

 (which involve the vibrational, shearing and torsional modes of motion of the 

 decks on which the master gyro and slave systems are mounted) by locating 



Fit 



3. Star trails across the zenith recorded in latitude 00° 08' South with a camera fixed 

 rigidly to the gyro head. The trails, 75 minutes (arc) in length, show by their width 

 the 1 -minute (arc) error produced by backlash in the pitch and roll servomotor gearing, 

 and by their overall straightness the higher quality of average vertical that is main - 

 tained. 



AUTOCOLLIMATOR 

 TUBE 



SLAVE TABLE 

 AND EQUATORIAL 

 TELESCOPE 



CENTER OF MOTION 

 IN SEAWAY 



VERTICAL AND NORTH- 

 SEEKING MASTER GYROS 



Fig. 4. Arrangement of master gyropendulum and observing station required to minimize 

 the effects of horizontal accelerations. 



the master compass above the metacenter, and to take observations directly 

 from the compass head. 



With the system mounted at a level on the ship that provides a clear view of 

 the sky, preferably unobstructed by stack gases, it is possible to adjust the 



