THE SUN'S MOTION IN SPACE. 201 



of the direction of the sun's motion, we rigidly adhere to the con- 

 dition that the sum of the squares of the errors shall be a minimum, 

 we have to take for granted that among the stars, the majority- 

 possesses a motion opposed to the solar motion, which, in the 

 observed motions, is combined with the parallactic. There is a 

 considerable number of stars whose motion, while similarly directed 

 to that of the sun, is conspicuously greater in amount. These 

 however, are not arbitrarily distributed. If a plane be drawn 

 through the axis of the point (b) and perpendicular to the plane of 

 the Milky- Way, one of the two hemispheres so formed is rich in 

 stars of this character, while the other is poor. Evidently this is 

 a peculiarity demanding further investigation. 



(115) Kapteyn, 1897 (Oct.)— In Oct. 1897 Kapteyn discussed 

 the velocity of the solar motion, and that of stellar motions, in 

 space. 1 The results will be found hereinafter : see 1898. 



(116) JVewcomb, 1897. — Newcomb 2 in his American Ephemeris 

 paper on the precessional constant, stated that Struve's result 

 corrected to the recent fundamental positions, becomes instead of 



R.A. = 273-°4, D,= + 27'°3, 

 273-4 34-9. 



Referring to Boss' general result previously quoted, and regarding 

 R.A. = 279°5, D.= +38-°7 

 as the most probable value of the apex of the solar motion 

 deduced from Stumpe's data, he concluded that the direction which 

 most probably represented the actual solar motion was 



R.A. = 277-°5, D.= +38-°0. 

 In section xx., the elimination of the parallactic motion from the 

 precession of each star is discussed, the distance (?) factors to 

 produce uniformity in the mean result being related to the mag- 

 nitudes. These are given in the next reference herein to 

 ^Newcomb's work. 



1 De snelheid, waarmede het zonnestelsel zich verplaatst in de ruinate, 

 en de gemiddele parallax der sterren van verschillende grootte. — Vers- 

 lagen der Afdeeling Natuurk., Dl. 6, 1897-8, pp. 238-244. 



2 Astronomical papers prepared for the use of the American Ephemeris 

 and Nautical Almanac, Vol. vin., Part i., The Precessional Constant. — 

 Washington, 1897, pp. 1 - 76. 



