46 



C. V. L. Charlier 



The observed proper motions were distributed into classes, so that, in x as 

 well as in ?/, class 0 embraces all proper motions between — 0."049 and 0,"ooo, class 

 1 those between -j- O."ooi and 4-! '050, class 2 those between -|- 0."051 and -|- O^'ioo 

 a. s. f., the classrange being always 0^050. The star in brackets belonging to class 

 10 in X was omitted in the calculation of the dispersions. 



The characteristics of the frequency curves for x and y given in the last row 

 and the last column were calculated in usual manner. The result is 



M{x) = + 0.66 ; M{y) = — 0.47 



0.1- =^ + 1 .13 ; Oy = -f 0.50 



For the stars, in the same square, of the 4th magnitude I obtained in the 

 same manner 



M{x) = + 0.B2 ; M{y) = — 0.71 



Ox = + 1-30; = -\- 0.557 



Using (75***) we hence deduce: 

 From the x: = -|- 0.304; 



The mean of both: = -f 0.267 



for the different squares 





= -1- 0.56 



: 



= + 0.92 



G,: 



+ 0.14 





— 0.44 



C,: 



+ 0.27 



C, : 



+ 0.46 





+ 0.75 



^10 ■ 



+ 0.14 



G,: 



-f 0.87 



Gn-- 



+ 0.54 





— 0.08 



Gn'- 



— 0.12 



from y: X^ = -|- 0.230. 

 In this manner I obtained the following values 



Mean : X, = -f 0.335. 



24. In the computation of a and M all observations deviating more than 

 4a from the mean were excluded. 



The values of M{x) and M{ij) for the diffe- 

 rent squares may be used for determining — or 

 provisionally for illustrating — the motion of the 

 sun in space. In the accompanying table I give 

 these values for the stars of the fifth magnitude. 

 The value of M(y), being negative in all squares 

 (and rather constant) shows that the motion of the 

 sun takes place towards a point (the »apex») in 

 the north hemisphere. Estimating the maximum 

 value of M{x) to 0.90 class-ranges (I do not intend 

 to give here a more accurate determination of 

 the position of tlie apex), the declination -—I) — 

 of the apex may be given approximately by 

 log D = 0.484 : 0.90, giving D = -[- 28**. 



Square 



M{x) 



M{y) 





+ 0.74 



— 0.39 





+ 0.75 



— 0.68 





+ 0.66 



— 0.47 





— 0.29 



— 0.54 



c\ 



— 0.59 



— 0.76 





— 1.30 



— 0.73 



c\ 



— 0.85 



— 0.40 





— 0.74 



— 0.57 





— 0.34 



— 0.35 





+ 0.14 



— 0.32 





+ 0.37 



— 0.44 





+ 0.67 



— 0.16 



Mean 





- 0.484 



