214 



REPORT ON 



Hence 



Forward Ritchie Compass. 



o = — 0.9803 + 10.000 A x + 7-482 B x -f 3.999 C x + 3.938 A — 2.631 E x 

 o=— 0.6394 + 7-482 A x + 6.317 B x + 1.969 C x + 2.334 A — 3.774 E x 

 o =—0.6193 + 3.999 A x + 1.969 A + 3:685 C x + 3.708 A + 1.665 A 

 o = — 0.0407 + A + i Cft*— <£) 

 o = + 0.0013 4- A 4~ A C, 



-^1 = + 0.0614 = + 3° 3 1 '- 

 A =' — 0.0076= — o 26.1 

 C x = + 0.0631 = + 3 36.9 

 D x = -)- 0.0427 = -(- 2 26.6 

 E x = — 0.0011 = — o 3.9 



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

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

 each compass from the observations made at Bio Janeiro. 



Equations of Condition at Rio Janeiro. 



Absolute Terms. 





























Coefficients of the Unknown Quantities. 



-1 



4 



u 



A 



"S-S 



tJ 73 



•H..S 







2 -a 





3 



a! 



rt « 











6| 



3^ 







S3 



P s 



• £ " 











i< 



fie 







A i 



*. 



C, 



-0, 



*• 



4- 290' 



— 320' 



— 840' 



— 160' 



— 250' 



— 160' 



— 500' 



+ 



1. 000 



+ o-SS6 



4- 0.831 



4- 0.924 



4- 0.383 



+ 3 6 ° 



— 410 



— 840 



— 120 



— 250 



— 160 



— 500 



+ 



1. 000 



4- 0.707 



4- 0.707 



4- 1.000 



0.000 



4- 390 



— 430 



— 840 



— 20 



— 250 



— 160 



— 37° 



+ 



1. 000 



+ 0.831 



4- 0.556 



4- 0.924 



— 0.383 



+ 35° 



— 43° 



— 97o 



+ 130 



— 180 



— 160 



— 460 



+ 



1. 000 



+ 0.924 



4- 0.383 



4- 0.707 



— 0.707 



+ 33° 



— 360 



IOIO 



+ 160 



— 160 



— 160 



— 500 



+ 



1. 000 



+ 0.981 



4-0-195 



4- 0.383 



— 0.924 



+ 3 2 ° 



— 34° 



— 880 



+ 280 



— 160 



— 160 



— 44° 



+ 



1. 000 



4- 1. 000 



0.000 



0.000 



— 1. 000 



+ 3°o 



— 34° 



— 720 



+ 39° 



— 160 



— 100 



— 420 



+ 



1. 000 



-j- 0.981 



— 0.195 



- 0.383 



— 0.924 



+ 280 



— 280 



— 610 



+ 41° 



— 160 



— 140 



— 35° 



+ 



1. 000 



4- 0.924 



-0.383 



— 0.707 



— 0.707 



4- 260 



— 260 



— 59° 



+ 44° 



— 160 



— 100 



— 33° 



+ 



1. 000 



+ 0.831 



— 0-556 



— 0.924 



— 0.383 



4- 240 



— 190 



— 59° 



+ 4°o 



— 160 



■ — 20 



— 33° 



+ 



r.000 



4- 0.707 



— 0.707 



— 1. 000 



0.000 



4- 2O0 



— 170 



— 5 IO 



+ 3 20 



— 160. 



— 60 



— 33° 



+ 



t.000 



+ 0.556 



— 0.831 



— 0.924 



4- 0.383 



4- 210 



— no 



— 510 



-f- 200 



— 230 



— 80 



— 33° 



+ 



1. 000 



4- 0.383 



— 0.924 



— 0.707 



4- 0.707 



+ 170 



— 90 



— 510 



+ 7° 



— 250 



— 80 



— 270 



+ 



1. 000 



+ 0.195 



— 0.981 



— 0.383 



4- 0.924 



+ 150 



— 90 



— 510 



— 20 



— 250 



— 140 



— 250 



+ 



1. 000 



0.000 



— 1. 000 



0.000 



+ 1. 000 



4- 140 



— 20 



— s IO 



— 190 



— 310 



— 100 



— 180 



+ 



1. 000 



— o- '95 



— 0.981 



4- 0.383 



4- 0.924 



+ 120 



— 10 



— Sio 



— 290 



— 33° 



— 80 



— 230 



+ 



1. 000 



-0.383 



— 0-924 



4-0.707 



4- 0.707 



+ 90 



— 10 



— 510 



— 3 IQ 



— 330 



— 80 



— 250 



+ 



1. 000 



— 0.556 



— 0.831 



4- 0.924 



4- 0.383 



Hence 



Normal Equations. ~ 



Admiralty Standard Compass. 



o = — 1. 2217 4" 17.000 A x 4- 8.442 B x — 5.641 C x 4- 0.924 D x 4- 0.383 A 

 o = — 0.7991 4- 8.442 A, 4- 8.310 B x 4- 0.462 C x — 1.205 A — 4-543 A 



= 4- 0.1662 — 5.641 A x 4- 0.462 B x 4- 8.691 C x 4- 3.900 A — 4-438 E x 

 o = — 0.0169 4- A 4- \ (A 2 — Q) 

 o = 4- 0.0009 4- A 4" -^1 £"i 



A x = 4- 0.0453 = 4-2° 

 A = 4- 0.0519 = 4- 2 



C 1 = -\- 0.0001 = 4- o 



A = 4- 0.0156 = 4- o 

 A = — 0.0009 = — o 



35-7 



58.5 

 0.2 



53-5 

 3-i 



