HANDBOOK OF MAGNETIC COMPASS 147 



Heeling : 



Errors, oscillation : 



Causes of— 16, 30, figure 19. 



Effects of— 16, 30, figure 19. 



Correctors — 31, figure 19. ♦ 



Adjustments for— flguro 19, 79, 135, 13G. 

 Magnet : 



Purpose— 31, figure 19, i;{3. 



Adjustments— 134, 130, SI. 



Induction in Flinders bar — 100. 

 Horizontal force instrument — 137. 

 Hour angle — 62. 



I 



Induced magnetism : 



Definition of— 6, 11, 13. 



Polarity of— 7, 14. 



Varies with— 13, 14, 20, 21, 29. 



Correction for— 31, figure 19, 81. 



Vertical— 21, 30. 



Horizontal— 22, 23, 24, 25, 26, 28, 30. 



In Flinders bar— 98, 93, 100. 

 Interaction of correctors : 



Spheres and compass needles — 92. 



Heeling magnet and Flinders bai" — 100. 



B magnets and Flinders bar — 98. 



Magnets and spheres — 101. 

 Iron core coils — 115. • 



J 



"Jig King" signal flag — 2. 



K 



"K" type compensating coils — 116, 108 (3). 



L 



Latitude, magnetic, effect on coefiicieiit with change of 30, 112, 13, 31, 21, 27. 

 Lambda (shielding) : 



Definition of— 137. 



Determination of— 137, 138. 



Uses of— 137, 135. 

 Liquid in compass — 72. 

 Local apparent time — 63. 

 Local hour angle — 62. 



M 



Magnet correctors, permanent — 31, 81, figure 19. 



Heeling magnet, (see heeling.) 



Semicircular B magnets — 31, figure 19, 81. 



Semicircular C magnets — 31, figure 19, SI. 

 Magnetic correctors, induced— 31 : 



Flinders bar. ( See Flinders bar. ) 



Spheres. (See spheres.) 



