200 G. H. KNIBBS. 



D. 0°, and obtains from 115 stars of proper motion at least # "4 



R.A. = 266-°1, D.= -0-7. 

 The paper is important as bearing on the relation of the determin- 

 ation of the precession-constant to the general discussion of proper 

 motions. 



(113) Kapteyn, 1897 ( May ) — Kapteyn continued his discussion 

 of the velocities of stars in space, reviewing the possibility of some 

 general trend in the motus peculiares of the stars. 1 His results 

 are more fully referred to hereinafter. See 1898. 



(114) Kobold, 1897 (July) — In continuation of his previous 

 investigations, Kobold 2 discussed in July 1897, the distribution of 

 the motus peculiares of the stars upon the assumption of two apices 

 for the solar motion, viz. 



(a) R.A. = 268-°25, D.= +31*°0, Argelanderian solution 



(b) 268-°25, - 3-°0, Besselian solution 

 and further for the apex 



(c) R,A. = 268-°25, D.= +10-°5 



Putting 



M = As cos (<j> -\p)' y N = As sin (0 - if/) 



in which As, <j>, and xp are respectively the observed proper motion, 



its direction, and ip the direction from the antiapex; and also q to 



denote the solar motion, and Ap the correction to the precession 



constant, Kobold found for these points the following results, viz.: 



Argelanderian Point. Besselian Point. Point c. 



Ap 



-0-0289 



-0-0277 





Mean N 



± 0-0934 



± 0-0847 





No. of + Ns 



505 



404 



456 



No. of - Ns 



388 



499 



447 



He further calculated, from the equation for M, the values of m/p, 

 or one of the angular components of the motus peculiaris of each 

 star, drawn perpendicular to the great circle from the antiapex. 

 The distribution of the errors shewed that if, in the determination 



1 Verdeeling der kosmische snelheden. — Verslagen der Afd. Natuurk. 

 Dl. 6, 29 Mei, '97 - 23 Apr. '98, pp. 51 - 60. 



2 Ueber die Vertheilung der motus peculiares der Sterne. — Astr. Nach., 

 Bd. cxliv., pp. 289-300, 1897. 



