The Butlierfurd Photographic Measures. 



143 



Table XYIII. — Parallax Equations. 

 Position-Angle. Star 23. 

















Residuals 

















in arc 



of 



Plate. 



Reduced Angle. 











great circle. 



1 



356°4'49" 



1. oar 



—1.142/ 



—79 



n + 8."=o 



— o".o8 



2 



5 12 



1. 00 



—1-13 



—79 



+31. 



= 



+ 



.20 



3 



4 49 



1. 00 



— i-i3 



—79 



+ 8. 



= 



— 



.08 



4 



5 20 



1. 00 



—0.08 



—73 



+39- 



= 



+ 



•3i 



5 



4 14 



1. 00 



—0.04 



—62 



—27. 



==0 



— 



•45 



6 



440 



1. 00 



— 0.04 



—62 



— 1. 



= 



— 



•13 



7 



5 7 



1. 00 



— 0.04 



—60 



+26. 



= 



+ 



.20 



8 



4 50 



1. 00 



+0.88 



-78 



+ 9- 



= 



— 



.08 



9 



4 57 



1. 00 



+0.88 



-78 



+16. 



= 



+ 



.00 



10 



5 



1. 00 



+0.89 



—77 



+19. 



= 



+ 



.04 



11 



442 



1. 00 



+0.90 



-76 



+ 1. 



= 



— 



• 17 



12 



4 58 



1. 00 



+0.90 



-76 



+17. 



= 



. + 



.02 



13 



5 11 



1. 00 



-fo.90 



-76 



+30. 



= 



+ 



.18 



15 



4 1 



1. 00 



+1.42 



+73 



—40. 



= 



— 



.07 



16 



4 13 



1. 00 



+I-45 



+66 



—28. 



= 



+ 



•05 



17 



3 59 



1. 00 



+1-45 



+66 



—42. 



= 



— 



• 12 



18 



424 



1. 00 



+1-45 



+65 



—17. 



= 



+ 



.18 



19 



3 4o 



1. 00 



+1-45 



+65 



—61. 



= 



— 



•36 



20 



4 39 

 356 441.0 = 



1. 00 

 Adopted 



+1-45 

 Mean. 



+65 



— ■ 2. 



= 



+ 



.36 



Normal Equations. 

 +19. ocu/ +10.423/ — 555.00IT — 14.00 = 

 +21.16 + 448.60 — 248.42 = 

 +97481.00 — 26185.00 = 



Solution. 

 n = + o". 3 334 ±0^.0584 

 y / = — o .6676 ±4 .237 

 a/ = +io .8423 ±4 .652 



\_w~\ = 5349- 



a =2500 // .62 

 Factor = .01213 



In Angle. Arc of great circle. 

 Probable error of one equation = ±12". 33 = ±o // .i496 



