318 Rutherfurd Photographic Measures. 



Table Y. — Parallax Equations. 

 Comparison Stars e and /. 



Normal Equations. 



4-18.000C.T +15.8300J/ — i.48oo7r + 0.5500 = o 



+29.1481 — 9.7778 — 2.8854 = o 



-r 34.4666 — 58.2440 = o 



Solution. 



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



TT = +2.0277 ±0.2001 - = +0.5680 ±0.0560 



y = +1.3500 ito.2792 y ^ +0.3781 =£10.0782 

 X = — 1.0511 ±0.2567 .1- = — 0.2944 ±0.0719 



Scale. Arc. 



Probable error of one equation = ±1.089 = ±o."305 



