HANDBOOK OK MAGNP7ri(' ('OMPAS8 149 



Poles: 



Geographic — 7, 9. 



Magnetic — 5, 7, 9. 



Red and blue, + and — , etc. — 7. 

 Precautions : 



Before adjustment— 1, 72, 73, 74, 75, 80. 



During adjustment— 1, 85, 86, 88, 89, 70, 32, 48, 49. 



Before compensation — 107, 128. 



During compensation — 124, 125-127. 



For maintaining deviation curves — 90, 125, 131. 



Q 



Quadrantal : 



Deviations— 22-27. 

 Curves— 22-27. 

 Causes— 22-27, 92, 93. 

 Spheres. (See spheres.) 

 Error from Flinders bar— 93. 



R 



Ranges, use of — 55. 



Reciprocal bearings, use of — 56. 



Records on compass — 89, 132, 109. 



S 



Semicircular : 



Curves— 16, 21, 32. 



Magnet correctors — 81, 31. 

 Shielding— 135, 137. 

 Ship's magnetism— 10-13, 103-107. 

 Signal flag, "Jig King"— 2. 

 Slewing : 



Flinders bar— 141, 142. 



Spheres— 139, 140, 94. 

 Sluggishness of compass — 33, 35. 

 Soft iron correctors : 



Flinders bar. (See Flinders bar.) 



Quadrantal spheres. (See spheres.) 

 Spheres, quadrantal 



Picture — fig. 18. 



Purpose— 31, 81, 



Adjustment— 32, 92, 78. 



Correction chart — fig. 31. 



Magnetization check — 74. 



Annealing — 74. 



Compass needle induction — 92, 101. 



Slewing— 94, 139. 



Slewing chart — figure 33. 



Problem— 94. 

 Sun's azimuth. (See azimuth.) 

 Subpermanent magnetism — 12. 



Summary of compass errors and adjustment — fig. 19. 

 Symmetrical horizontal soft iron — 23, 24. 

 Symmetrical magnetic tiekl8 — 102, 32. 



