326 Rutherfurd Photographic Measures. 



IX 



DISCUSSION OF RESULTS. 



It is of great interest to compare the photographic places of the 

 various stars with those resulting from the Yale and Konigsberg 

 heliometer measures. This has accordingly been done, and the 

 results are given in tabular form at the end of the present section. 

 The first two columns of the table contain the number, and Besse- 

 lian designation of the star. The rest of the table is divided into 

 two parts, the first of which relates to the right ascensions. The 

 column headed Yale contains the value of this co-ordinate, as given 

 by the Yale* heliometer measures, and referred to the equator 

 and equinox of 1873.0. The next column, headed N. Y., gives 

 the seconds of right ascension, as contained in the photographic 

 catalogue at the end of Section VIII. The next column, headed 

 Y. — N. Y., contains the direct differences of the last two columns. 

 This is followed by the values of .27 (Y. — K.), or .27 (Yale — 

 Konigsberg), which would be equal to Y. — N. Y., if no discordance 

 existed between the photographic and heliometer results.f The 

 next column, headed Biff., gives the amount of such discordance. 

 The numbers in this column show that the photographic results are 

 of the highest accuracy. In fact, they compare very favorably with 

 the heliometer residuals, which are set down in the last column, 



* In using Elkin's table of final results of the Yale measurements, the following 



errata have been corrected : 



Star No. 38, 24. p, Declination should be 33". 50. 



" " 58, Anon. 31, Precession in R. A. should be -\-<,2 f '-4^>9°' 



11 " 66, Anon. 38, Declination should be 23 29' 52". 39. 



" " 66 Precession in R. A. should be -\-S3 ,, - 2 9^°* 



11 " 66 Sec. Var. in R. A. should be -j-* "-^ 1 * 



The errata for Nos. 38 and 66 have been kindly communicated by Dr. Elkin. 



f The Konigsberg measures are given by Bessel for 1840. The Yale 



measures are referred to 1885. The New York measures of 1873 should 



12 

 therefore differ from Yale by — , or .27 (Y. — K.). 



