MAGNETIC O IS S E R V A TIOXS. 



217 



The resulting normal equations are 



o = — 2.5365 4- 22.000 A, 4- 7.4S2 /.', — 3.999 C, + 3.938 D, + 2.631 A\ 

 o = — 1.0294 -f 7.4S2 A, + 9.6S5 J>\ -f 1.969 C, — 2.334 X>, — 3.77 1 /■', 

 o = — 0.3901 — 3.999 ,4, 4- 1.969 B l 4- 12.316 C, 4- 3.708 X>, — 1.665 E, 



o = — 0.0340 4- A + i W — Cfi 

 o = 4- 0.0008 4- -^1 + -^'1 C", 



Hence 



^ = 4-0.1143 = 4-6° 3»'-8 

 A = 4- 0-0146 = 4- ° 5°-3 

 C, = 4- 0.0555 = + 3 i°-9 

 Z>, = 4- 0.0354 = 4- 2 1.8 

 .£, = — 0.0016 = — o 5.5 



The following are the equations of condition, together with the resulting normal 

 equations, and the values of the coefficients A u -B,, C\, D u E^ as determined for 

 eacli compass from the observations made in Magdalena Bay. 



Equations of Condition at Magdalena Bay. 



Absolute Terms. 





Coefficients of the Unknow 



11 Quantities 



















2 -i 



rt 



1- 



"S ^ 



"2 "y 



7 .£ 















■3 = 



s % 



v § 



£ "^ 



t = 



'? s 















= 2 















3* 







&'< 





,-■& 

 h 





A \ 



B t 



c, 



D, 



E, 



4- 20' 



IO' 



— ioo' 



— 300' 



— 300' 



— 540' 



+ 



[.000 



— 0.707 



— 0.707 



4- I. OOO 



0.000 



4- 60 



IO 



— 180 



— 37° 



— 290 



— 460 



+ 



I. OOO 



— 0.831 



— 0.556 



4- 0.924 



- 0.383 



+ no 



+ So 



— 1S0 



— 210 



2IO 



— 3S0 



+ 



I. OOO 



— *>-9 2 4 



— 0.383 



4- 0.707 



— 0.707 



4- 140 



4- 160 



— 1S0 



— 130 



— 210 



— 290 



+ 



I. OOO 



— 0.981 



— 0.195 



4- 0.3S3 



— 0.924 



4- 180 



4- 170 



_ So 



— 130 



— 120 



— 200 



+ 



I. OOO 



— I. OOO 



0.000 



0.000 



I. OOO 



+ -3° 



+ 320 



+ 170 



— 210 



4- 5° 



+ 50 



4- 



I. OOO 



— 0.9SI 



4-0.195 



- 0.383 



— 0.924 



+ 230 



+ 320 



+ 33° — 130 



4- 130 



+ 210 



4- 



I. OOO 



— 0.924 



+ 0.383 



— 0.707 



— 0.707 



+ 2 5° 



+ 3 2 ° 



+ 320 _ 120 



+ 210 



4- 210 



4- 



I. OOO 



— 0.831 



4- 0.556 



— 0.924 



— 0.383 



4- 220 



+ 3 20 



-|- 160 1 — 40 



+ 3°o 



-j- 210 



4- 



I. OOO 



— 0.707 



+ 0.707 



— I. OOO 



0.000 



-j- 220 



+ 320 



-j- 160 — 40 



+ 380 



+ 3°° 



4- 



I. OOO 



— 0-556 



4- 0.S3I 



— 0.924 



4- 0.383 



+ 160 



+ 320 



+ 150 |4- 40 



+ 3S0 



+ 370 



+ 



I. OOO 



—0.383 



+ 0.924 



— 0.707 



4- 0.707 



4- 100 



+ 2 3° 



4- 60 j 4- 40 



+ 3S0 



+ 2tO 



4- 



I. OOO 



— 0.195 



-j- 0.9SI 



— 0.3S3 



4- 0.924 



+ 4° 



+ '5° 



— 100 | f- 40 



4-37o 



4- 210 



+ 



I. OOO 



0.000 



-j- I. OOO 



0.000 



4- I. OOO 



+ 30 



4- 70 



— 190 



1 — 50 



+ 290 



+ 120 



+ 



I. OOO 



+ 0.195 



+ 0.9SI 



+ 0.3S3 



4- 0.924 



Hence 



Normal Equations. 



Admiralty Standard Compass. 



= 4- 0.5789 4- 14.000 A, — S.S25 i? L 4- 4-717 c > — I - 6 3 1 A — I -°9° E i 

 o = — 0.4310 — 8.825 A, 4- 7.545 B x — 0.816 <7, 4- 0.934 D x 4- 4-272 E x 

 = 4-0.2352 4- 4.717 ^, — 0.816 i? t 4-6-456 C, — 4-554 A + 3-784^, 

 o = — 0.0169 4-.Z?, 4- \ {B? — 67) 

 o = 4~ 0.0009 -\~ B i -\- B 1 C y 



A x = 4- 0.0026 = 4-0° 9'. 1 



i?, = 4- 0.0559 = 4- 3 12.1 



C, = — 0.0204 = — 1 10.3 



Z>, = 4- 0.0156 = 4- o 53.5 



E x = 4- 0.0002 = 4- ° °-8 



28 January, 1873. 



