The Rutherfurd Photographic Measures. 



139 



Table XVIII. — Parallax Equations. 

 Position-Angle. Star 27. 















Residuals 















in arc of 



Plate. 



Reduced Angle 











great circle. 



2 



I77°I4 / 9" 



1.00a/ 



—1.13/ 



4-iS3.n 



— 59 



"=o 



4-".p 3 



3 



13 57 



1. 00 



— I-I3 



+1S3. 



— 7i 



= 



— -03 



10 



14 59 



1. 00 



+0.89 



4-178. 



— 9 



= 



4- .21 



11 



15 3 



1. 00 



+0.90 



4-176. 



— 5 



= 



4- -23 



12 



14 10 



1. 00 



4-0.90 



+176. 



-53 



= 



— -05 



13 



13 4 



1. 00 



4-o.go 



4-176. 



— 124 



= 



— -39 



15 



16 11 



1. 00 



4-1.42 



— 169. 



+ 63 



= 



— .12 



16 



16 11 



1. 00 



4-1-45 



—151- 



+ 63 



= 



— .08 



18 



17 20 



1. 00 



4-1-45 



—149. 



4-132. 



= 



+ .28 



20 



16 14 



1. 00 



4-1-45 



—149. 



+ 66. 



= 



— -07 



177 15 8.0 = Adopted Mean. 



Normal Equations. 



4- 10. 00a/ 4- 7- Io y4- 454-°°n — 2.00 = 



4-14. 10 — 670.99 4- 438-50 = 



4-287354.00 — 107966. 00 = 



Solution. 

 II =4- o // .3797 ± o // .o737 

 y' =— 7 .1257 ±12 .65 

 a/ = — 11 .8966 ±14 .69 



[w] = 13187. 



a = io74 /r .6o 

 Factor = .005 2 1 



In Angle. Arc of great circle. 

 Probable error of one equation = ± 29 // .27 = ± o // .i525 



