The Rutherfurd Photographic Measures. 135 



Table XYII. — Parallax Equations. 

 Comparison Stars 54 and 5. 













Residuals. 





Plate. 











Scale. 



Arc. 



1 



1. oar 



—1.142/ 



—1. gin 



+2.96 = 



— O.IO 



—0" 



'•03 



2 



1. 00 



—1-13 



— 1.90 



+3.72=0 



+0.68 



+ 



•19 



3 



1. 00 



— i- ?3 



— 1.90 



+2.48 = 



-0.56 



— 



.16 



9 



1. 00 



+0.88 



— 1.S9 



+ 1.25=0 



+0.34 



+ 



.10 



10 



1. 00 



+0.89 



—1.86 



+i.55=o 



+0.68 



+ 



•19 



11 



1. 00 



+0.90 



—1.84 



+0.58=0 



—0.27 



— 



.08 



12 



1. 00 



+0.90 



—1.84 



—0.32=0 



— 1.17 



— 



•33 



13 



1. 00 



+0.90 



—1.84 



+1.16=0 



+0.31 



+ 



■09 



15 



1. 00 



+1.42 



+ I-77 



-3-35=o 



— 1. 01 



— 



.28 



16 



1. 00 



+1-45 



+I-59 



—1.54 = 



+1.17 



+ 



•33 



17 



1. 00 



+I-45 



+ 1.59 



— 1. 71 =0 



+1.00 



+ 



.28 



18 



1. 00 



+1-45 



+1-57 



— 3-37 =0 



—0.68 



— 



•19 



20 



1. 00 



+1-45 



+ I-57 



—3-i5=o 



[vv~\ 



— 0.46 



= 6.96 





•13 



Normal Equations. 

 +13.00002;+ 8.29003/ — 6.8900II — 0.2400=0 

 + 18.2763 +9.8622 — 26.2564 = 

 +41-1755 —47-5103=0 



Solution. 



In units of 2d dec. place of scale. In Arc. 



11 = +0.8680 ±0.1203 n = +o // .243i ±o // .0337 

 y = +1.0570 ±0.2044 y = +o .2961 ±0 .0573 

 x = — 0.1955 ±0.2369 &* = — o .0548 ±0 .0664 



Scale. Arc. 



Probable error of one equation = ±0.5626 = ±o // .M576. 



