74 



Sven Wicksell 



Vertex III. Within au ellips having its major axis perpendicular to the di- 

 rection toward the vertex I. The axes are a = 6°.8 b = l°A. 



In fig. 1 the vertices are denoted hy a cross. The length of the limbs of 

 the crosses denote the axes of the above error ellipses. Obviously the system of 

 vertices may be regarded as a galactic system. Hence the systematic variation of & t 

 has no effect on their position. 



Fig. 1. 



The vertices for q' = 1, 0.75, 0.62, 0.45. 

 The dotted great circle is the plane of the Milky Way and the star is its pole. 



29. The higher characteristics it is most expedient for us to compute referred 

 to the system III. The differene between the characteristics referred to system III 

 and those referred to the vertex-system will be of the order of magnitude of the mean 

 errors. Thus the figures given in this paragraph might as well be regarded as be- 

 longing to the vertex-system of coordinates. 



I here give all the characteristics referred to system III. Before that I will 

 once more write down how the axes of coordinates in system III are orientated. 



We have taken 



the Z7""-axis towards the point a 



» F (s, -axis » » » a 

 » W^-axis » » » a 



= 270°.o 5 = 

 = 33ô°.7 S 

 = 188°.5 S = 



— 15°.o 

 + 56°.9 

 + 28°.7. 



