48 



C. V. L. Charlier 



111 table 10 I give the values obtained for M{y) — and partly for M{x) — 

 for the 24 squares at both sides of the eqvator. In the three last columns are 

 given the number of stars in the different cases. 



The mean values are the following: 





4th Magnitude 









M{y) = 



— '03165 from 





to 





M{y) = 



— 0. 02616 » 





» 





Mean = 



— 0" 02890 











oth Magnitude 









M{y) = 



— 0." 02420 from 





to 





M(y) = 



— 0. 02166 » 



^1 



» 



A2 



Mean = 



— O; '02292 











6th Magnitude 









M{y) = 



— 0'. '02458 from 





to 



^12 



M{y) = 



— 0. 01726 » 





» 



As 



Mean = 



— O; '02092 









Obs! The numbers in tab. 10 are all expressed in the class-range (0."o60) 

 as unit. 



It may be observed that the value of M{y) for all the three magnitudes coines 

 out larger from the squares Cj to Cjg than from the corresponding squares south 

 of the equator. This difference may be due to a somewhat differing principle for 

 excluding large proper motions *). 



To the 6th magnitude the »Preliminary Catalogue of Stars» by Boss, which is 

 used as source of the proper motions can be considered as complete. The stars of 

 the magnitude 6 to 7 are only very incompletely represented in the catalogue. I 

 have however considered it possible to use them in this preliminary investigation, 

 because the choice of the stars, taken up in the catalogue, seems not to have been 

 done in a S3'stematic manner with regard to the proper motions. For stars fainter 

 than 6"' all stars, having a proper motion larger than 0."250 in a year, have been 

 excluded. 



The resulting value of Xj from the deduced values of M{y) in tab. 10 is 



= -|- 0.351. 



The value of Xj used by Kapteyn, as may be deduced from his values of the 

 parallaxes cited in the 5th §, is X^ = -|- 0.65. It has been impossible for me to 

 reconcile such a large value of Xj with the proper motions of Boss. As I propose 

 to determine X^ in connection with an investigation of the systematic motion of the 

 stars (the »starstreams») I will not for the present try to explain this difference, 



*) I will come back to the question of the calculation of Xj in the next memoir. 



