MAGNETIC OBSERVATIONS. 



213 



Hence 



Hence 



AFTER BINNACLE COMPASS. 



o = 0.9599 + 10-000 A l 4- 7.482 t 4- 3.999 C, + 3.938 Z>, 2.631 EI 



o-7253 + 7-482 A, + 6.317 l + 1.969 <7, + 2.334 D l 3.774 , 



= o-44i3 + 3-999 ^ + 1-969 A + 3-685 C, + 3.708 D l 4- 1.665 ^, 



o = _ 0.0385 + A + i (A s c; 1 ) 



o = + 0.0018 +.,+ ^ c; + 0.0047 W c,') 



A l= = -{- 0.0062 = -f o 2i'-3 

 -5, = + 0.0801 = + 4 35.2 



c; = 4- 0.0362 = 4-2 4.6 

 A = 4- 0.0360 = 4-2 3.6 



EI = 0.0048= o 16.3 



AFTER RITCHIE COMPASS. 



o = 2.5540 4- 10.000 A, 4- 7.482 , 4- 3.999 C l 4- 3.938 Z>, 2.631 , 

 o = 1.9282 4- 7.482.4. 4-6.317.5, 4- 1.969 C, 4- 2.334 A 3-774 -, 

 o = 1.0844 4- 3-999 ^i + 1-969 A + 3-685 Ci 4- 3.708 ZJ, 4- 1.665 ^i 

 o = 0.0340 4- D l 4- \ (B* Cf) 



= 4- 0.0008 4-^4-^, c, 



A! =-- 4- 0.1030 = 4-5 54'. 2 



A = 4- 0.1385 = 4- 7 56.0 



C, = 4- 0.0859 = + 4 55-4 



A = i: 0.0281 = 4- i 36.6 

 t = 0.0127= o 43-7 



Hence 



o 

 o 

 o 

 o 



o 



FORWARD ALIDADE COMPASS. 



-5 26 5 + 10.000 A, 4- 7.482 l 4- 3.999 C, 4- 3.938 Z>, 2.631 

 -3589 + 7-482^,4-6.317^ 4- 1.969 C, 4- 2. 3 34Z>,_ 3.774 

 0.3022 4- 3.999 A t 4- 1.969 t 4- 3.685 C t 4- 3.708 Z, 4- 1.665 



0.0235 +A + i W-Q) 



. 0.0007 + A, 4- B, c, 4- 0.0125 (A 2 QO 



^i = + 0.0359 = + 2 3'-5 



A = 4" O.OOOI = 4~ O O.2 



c, = 4- 0.0188 = 4-1 4.8 

 A = + 0.0237 = 4- i 21.4 



t = 4" 0.0007 = 4" 2 -4 



Hence 



FORWARD BINNACLE COMPASS. 



o = 0.1396 4- 10.000 A l 4- 7.482 S l 4- 3.999 C, 4- 3.938 Z>, 2.631 EI 

 o 0.0593 4- 7.482 A, 4- 6.317 B^ 4- 1.969 C, 4- 2.334 Z>, 3.774 ., 

 o = 0.1831 4- 3.999,4, 4- 1.969^, 4-3.685 C, 4-3.708,0, 4- 1.665^, 

 o = 0.0369 -f D, 4- \ (* C, 1 ) 

 o = o.oon 4- E, 4- ^ C, 



^, =0.0159 = o 54'- 7 

 .Z?, = 4- 0.0072 = 4-0 2 4-6 

 C, = 4- 0.0253 = + ' 26 -9 



Z>, = 4- 0.0372 = 4-2 7.8 

 E l> ^= 4- 0.0009 = 4-o 3- 2 



