the Magnetic Compass in Aeroplanes. 



Deviation from Magnetic North in card degrees 

 *> qOOOO OOOOq 



47.°) 



II 



II 





I 





Suggested quadrantal compensation. — To correct perfectly 

 for the quadrantal error, soft iron is necessary. It must 

 also be possible to vary the intensity of its effect as the tilt 

 changes. These conditions would be fulfilled by a pair of 



Phil. Mag. S. 6. Vol. 32. No. 191. Nov. 1916. 2 K 



