STUDIES IN STELLAR STATISTICS. IH. 41 
have therefore used the values (17) in the following computations. When 
the other spectral types have been examined regarding their distribution 
in space we are able to obtain a more accurate value for the position 
of the axis of rotation of the galaxy. Grophicalimepreeentaisın of the 
IS. Galactic system of coordina- function — I(A) 
tes. The galactic system being a sy- 
stem of revolution no direction in the 
XY-plane of the galaxy is by itself 
indicated as the axis of X^. The 
most natural choice of this axis seems 
therefore to be the direction from the 
centre to the sun, or, more precisely, the 
projection of this direction upon the 
AX? Y?-plane. Consequently I choose 
this direction as the Y°-axis. 
The coordinates of the anticentre 
are, according to $ 14, 
a = 295°,55 , 
A 
9.62 . 
[eni 
d = LE! 
and has the direction cosines 
lh = + 0.2435 
m, = — 0.5094 
n, = + 0.8253 
Using the direction cosines of 
the Z?-axis given in the preceding S 
we find for the angle between the 
anticentre and the pole of the galaxy the value 77°.43,! 
Let |, m,, n, be the direction cosines of the Z?-axis, 1,, m,, n; 
those of the anticentre and /,, m,, n, those of the X'-axis, we get 
for the determination of these quantities the equations 
! The coordinates of the Sun referred to these axes are consequently: 
X, = 18.21 sin 770.45 = 17.77 Siriometers. 
[4 / 2 J 4 5 é 
18.21 cos 77.43 = 3.96 
N 
I 
and Y, = 0. 
Nova Acta Reg. Soc. Se. Ups., Ser. 4, Vol. 4, N. 7. Impr. ?*/s 1916. 6 
