THE SUN S MOTION IN SPACE. 



193 



tively. 1 The results have been subsequently considered in dis- 

 cussions of the solar motion. 



(101) Kobold, 1895 (Jan.) — In continuation really of his pre- 

 vious investigations, Kobold contributed to the Astronomische 

 Nachrichten in 1895, a paper on the relation between the different 

 methods of investigating the motion of the solar system. 2 His 

 general equations contain terms representing the components of 

 absolute motion, both of the sun and of the stars, that is to say 

 the so-called motus peculiaris of both are taken into consideration. 

 He points out that if Airy's method is applied to Yogel's 51 stars 

 the result is 



R.A. = 247-°0, D.= +47-°9, R. = 0-191 

 instead of 206-1 45-9 



R being the motion at the mean distance of the 51 stars, but 

 points out that the weight of a determination based upon so incon- 

 siderable a number of stars is small. The mathematical theory 

 of the difference between the methods is fully exhibited. 



(102) Kobold, 1895 (Mar.) — Kobold discussed the relation of 

 the Argelander and Airy to the Besselian method of investigating 

 the solar motion, in March 1895. 3 He states (a) that Argelander's 

 and Airy's methods should give the same point for the sun's apex 

 of motion, the fundamental supposition being that the motus 

 peculiaris perpendicular to the line of sight will mutually cancel 

 one another. The apex points lie on both sides of R.A. 275° 

 D. + 30° in a narrow zone parallel to the Milky Way: it is not 

 possible that the true apex lies within this region. (b) The 

 method dependent upon motion in the line of sight supposes that 

 the motus peculiaris in that direction vanishes, and will give a 

 result in agreement neither with the method of Argelander nor 



1 Ueber die mittleren Parallaxen von Sternen verschiedener Grossen- 

 classen und verschiedener scheinbaren Bewegungen — Astr. Nach. Bd. 

 cxxxvi., pp. 289 - 300. 



2 Ueber die Beziehungen verschiedener Methoden zur Untersuchung 

 der Bewegung des Sonnensystems. — Astr. Nach. Bd. cxxxvu., pp. 343- 

 348, 1895. 



3 Bemerkungen zur BesseFschen Methode der Untersuchung der 

 Eigenbewegung. — Astr. Nach. Bd. cxxxvu., pp. 389 - 398, 1895. 



M— Nov. 7, 1900. 



