80 RELATIONS PERTAINING SIMPLY [BoOK. L 



log cos (45 Ji)sini(^ + i) . . 9.5164915w 

 log cos (45 ifl) cos * (E-\-l) . . 9.7636042 n 

 whence * ( + J) = 209 30 49&quot;.94 : log cos (45 i fl) = 9.8239669. 



Therefore, we have E= 42626 55&quot;.33, I 725 15&quot;.45, or, what amounts 

 to the same thing, E = 6626 55&quot;.33, 1= 35234 44&quot;.55; the angle 45 i *, 

 obtained from the logarithm of the sine, is 4810 58&quot;.12, from the logarithm of 

 the cosine, 4810 58 / .17, from the tangent, the logarithm of which is their differ 

 ence, 48 10 58&quot;.14 ; hence b = 62r56&quot;.28. 



According to the other method, the calculation is as follows : 



log tan d .... 9.1893062 C.logcos .... 0.3626190 



log sin a . . . . 8.8719792 log cos (C e) . . 9.8789703 



log tan .... 0.3173270 log tan a .... 8.8731869w 



C= 6417 6&quot;.83 log tan/ ..... 9.1147762w 



K = 40497.57 /= 35234 44&quot;.50 



log sin J ..... 9.1111232 n 



log tan (C ) . . 9.9363874 



log tan b ..... 9.0475106 n 

 b= 621 56&quot;.26. 



For determining the angle E we have the double calculation 



log sin s . . . . 9.6001144 log sin e ..... 6.6001144 



log cos a . . . . 9.9987924 log cos/ ..... 9.9963470 



C. log cos* . . . 0.0026859 C. log cos d .... 0.0051313 



log cos E . . . 9.6015927 log cos E ..... 9.6015927 

 whence E = 66 26 55&quot;.35. 



70. 



Something is still to be added concerning the parallax and aberration, that 

 nothing requisite for the computation of geocentric places may be wanting. 

 We have already described, above, a method, according to which, the place 

 affected by parallax, that is, corresponding to any point on the surface of the 



