238 



REPORT — 1866. 



The computation of the value of fi is as under 



log cos «" 

 log cos h' 



ar. CO. log cos S 

 log sin TT 

 ar. CO. log(l— m) 

 ar. CO. log 3-663 



sum = log J,,, 



log/ 

 sum = log sin \p 



0-00000 

 9-96557 



0-03594 

 8-23308 

 0-00491 

 9-43616 



logo? 

 log 2/ 



1-22583 



0-97909 



diff. = logtanM 0-24674 

 u 60 27 55 



7-67566 logy 0-97909 



9-69752 ar. CO. logeosM 0-30720 



7-37318 ar. CO. logR' 8-41123 



' sum = log/ 9-69752 



FormulcB for and Calculation of \ and /3. 



We are now in a position finally to determine X 

 the -eelenographical longitude, and /3 the selenogra- 

 phical latitude of the measured point by the aid of 

 the following angles, C, \", and x (see fig. 13) for 

 X=X"+r, and tan /3 = cos\" tan(x + b'). 



C'=u-f C= the inclination of the plane of the arc 

 p, to the apparent latitude circle of the moon (see 

 fig. 11, p. 234). 



„, , - „ tan C sin v 



tan v= tan u cos U , tan X = ; -^, 



^ ^ cos(x + 6) 



X"+ when W— when E, x+ 'w^ten C is N, —when 



Uomputation. 



29 53 23 



8 7 

 29 45 ] 6 

 Fig. 13. 



D Pole 



2) Equator 



Theophilus is situated in 26 10 37 W. long, 

 and 11 22 55 S. lat. 



