MAGNETIC OBSERVATIONS. 



217 



The resulting normal equations are 



Hence 



o = 2.5365 + 22.000 A l + 7.482 , 3.999 C, + 3.938 A + 2-631 &i 

 o= 1.0294+ 7.482^+9.685^,+ 1.969 C, 2.334 A 3-774 -E, 

 o = 0.3901 3.999 A l + 1.969 ^ + 12.316 C l + 3.708 A I - 66 5 A 



0.0340 + A -{- ^ (-^i* ^V) 



o = + 0.0008 + l + B^ C i 



32 '.8 

 50.3 

 10.9 



1.8 



5.5 



.5,= + 0.0146 = + o 

 C", == + 0.0555 = + 3 



A = + 0-0354 = + 2 



l = 0.0016 = o 



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

 equations, and the values of the coefficients A^ B,, C,, Z> 15 E u as determined for 

 eacli compass from the observations made in Magdalena Bay. 



EQUATIONS OF CONDITION AT MAGDALENA BAY. 



Hence 



o = + 0.5789 + 14.000 



o= 0.4310-- 

 o = + 0.2352 + 

 o = - 0.0169 + 

 o = + 0.0009 + 



8.825 

 4.717 



A + 



Normal Equations. 

 ADMIRALTY STANDARD COMPASS. 



t 8.825 A + 4-7 r 7 c i I-63 1 D\ 1.090 , 

 i + 7-545 A - Sl6 c i + -934 A + 4-272 -Ei 

 0.816 B l + 6.456 C, 4-554 A + 3-74 t 



A l = + 0.0026 = + o 

 ^,= + 0.0559 = + 3 

 C l = 0.0204 = i 



A= + .i5 6 = + 

 t = + 0.0002 = + o 



9.! 



I2 - T 

 10.3 



53-5 

 0.8 



28 January, 1873. 



