ON TIIE SQUARE BAR MICROMETER. 



175 



Right Ascension Correction, Equation (18) 



\ tan 2 i sin 2 q + 2.53 

 tan £ sin q tan 8 + 2.67 



A (a' - a) 



0.07B 



0.403 

 0.426 



+ 5.20 

 a. a (15 cos 8) 



0.716 



n 9.384 



9.216 



1st term -0.207 



w 9.316 



tan £ sin q tan 8 

 2k (d'-d) 

 a. c. (15 cos 8) 



0.426 

 9.468 

 9.216 



2d term +0.129 



9.110 



Declination Correction, Equation (20) 



tan* sin 3 q 



ff* 



1st term 



tan 2 £ cos 2 q 

 {d< - d) 



2d term 



A (8' - 8) 



+ 1.40 

 + 1.00 



+ 2.40 



0.58 



0.46 



// 



1.04 



0.146 



0.380 

 n 9.384 



n 9.764 



0.493 

 n 9.167 



n 9.00* » 



Curvature Correction, Equation (0). 



cos 8 sin 8 

 Correction 



32.6 : table V. gives m r 

 25.2 J table V. gives m 



0.37 X 

 -0".09. 



?n f — m 



tt 



0.58 

 0.34 



0.24 



Proper Motion Correction, Equations (8) and (9) 



A a' 



AS' 



15 cos 8 



Corr. in a 

 Corr. in 8 



+ .0049 



.101 

 32.6 



s .54 

 0".97 



7.690 

 9.004 

 1.513 



0.784 



n 9.733 

 n 9.987 



Summary . 



a' — a. 



m. ft. 



Uncorrected +2 23.38 



Refraction — 0.08 



Curvature 



Motion - 0-54 



Corrected +2 22.76 



y-s. 



// 



8 58.71 

 1.04 

 0.09 

 0.97 



9 0.81 



Example II. — Barnard's comet, 1885 II., observed at Harvard Colleg 



ob 



servatory 



42°22'.8), July 12, 188 



Sq 



,dj listed to apparent motion 



as by case III. of article 10. Dia 



O 



884".0 



S 







r 42'. i 



