154 Parallax of 61 2 Cygni, deduced from 



Table XXII. — Wilsing's Measures. 

 (See Paragraph 46.) 



No. of 



Mean of Residuals. 



Weight. 





Point 















on 







With Paral. 







Mean Date. 



Curve. 



Wilsing. 



With 

 Parallax. 



and Atmos. 

 Dispersion. 



Plates. 



Expos. 





I 



+.041 



—.066 



—■'073 



2 



4 



1890 Oct. 18 



2 



—.039 



— .140 



— .142 



I 



2 



Nov. 5 



3 



+.001 



—.047 



—.084 



I 



2 



Dec. 17 



4 



+•031 



4-. 042 



— .041 



I 



2 



1 89 1 Feb. 4 



5 



—•039 



— .010 



+.052 



6 



12 



May 13 



6 



—.179 



-.165 



—•145 



4 



8 



June 14 



7 



+.071 



—.015 



—.003 



12 



24 



Aug. 25 



8 



+.031 



—.063 



—.047 



12 



24 



Sept. 17 



9 



+.111 



+.018 



4-. 026 



10 



19 



Oct. 13 



10 



+•131 



+.077 



+.066 



8 



16 



Nov. 11 



11 



+.151 



+.111 



+.069 



9 



17 



Dec. 17 



12 



+.091 



+.088 



+.018 



7 



14 



1892 Jan. 15 



13 



— .009 



+.032 



+•043 



5 



15 



May 16 



14 



+ .OII 



+.030 



+.038 



4 



II 



Juue 15 



15 



— .009 



4-.007 



— .061 



6 



40 



1893 Jan. 13 



16 



—•159 



—.080 



—■043 



3 



19 



Mar. 24 



17 



— .169 



—•093 



—•054 



3 



24 



April 15 



18 



—.089 



— .021 



— .014 



4 



34 



May 14 



19 



—.049 



— .019 



+.004 



4 



32 



June 11 



20 



4-. 021 



+.012 



+.026 



3 



24 



July iS 



21 



-j-.OII 



— .02S 



— .002 



3 



25 



Aug. 15 



22 



+•031 



— .026 



— .022 



2 



18 



Sept. 8 



47. Several astronomers have investigated the parallax of 

 these stars by measures with reference to the point mid-way be- 

 tween 61 1 and 61 2 ; others with reference to either star indepen- 

 dently of the other. In Table XXIII are gathered many of the 

 results of such investigations where the stars were .individually 

 observed. When the same measures have been reduced in several 

 different ways or by different persons, that result which is re- 

 garded as definitive has been printed in heavy type, the lightface 

 type being used in other cases. The numbers in the last column 

 refer to the list of reference books given on pages 159-160. 



