ASTRONOMY: W, S. ADAMS 419 
TABLE III 
CAMPBELL 
MOUNT WILSON 
SPECTRAL 
TYPE 
v' 
Corrected! 
v' 
Corrected^ 
OandB 
9.0 
9.0 
0*.031 
8.2 
8.2 
0" 
.016 
A 
8.6 
6.8 
0 .031 
10.0 
7.7 
0 
.019 
F 
9.0 
7.8 
0 .031 
10.1 
8.8 
0 
.011 
i) 
11.0 
9.6 
0 .031 
flO.6 
\11.5 
9.2 
10.0 
0 
0 
.013 
.014 
M 
15.6 
13.6 
0 .031 
12.6 
10.9 
0 
.015 
iji' corrected for stream motion. 
In his later discussion of the solar motion as derived from the several 
spectral types Campbell has given the average radial velocities with a 
constant correction K applied to the velocity of each star. This con- 
stant has a value ranging from about zero for the F and G stars to over 
4 km. for those of type B. If these results are treated in the same 
way as those of Table III we obtain the following values: 
TABLE IV 
TYPE 
v' 
CORRECTED 
0 andB 
6.5 
6.5 
O'' 
.031 
A 
9.6 
7.4 
0 
.031 
F 
9.5 
8.3 
0 
.031 
G 
9.1 
7.9 
0 
.031 
K. ...... 
13.2 
11.5 
0 
.031 
M. 
16.1 
^ 14.0 
0 
.031 
The constant K as used by Campbell is the average velocity taken 
according to sign for the stars of each spectral class, and is dependent 
upon the value of the solar motion. For all of the Mount Wilson stars 
the same value, V = 20 km., has been used. This gives the following 
average velocities taken according to sign: 
B +1.26; A -0.24; F -0.86; G +0.05; K -1.18; M +0.31. 
A change in the value of V from 20 km. to 19 km. would reduce the 
value for the B stars from +1.26 km. to +1.06 km. These quantities 
must be regarded as very moderate in size. 
It appears clear from the Mount Wilson results given in Table III 
that the variation in velocity with spectral type is very gradual for these 
distant stars; and except in the case of the M stars, which, because of 
their number, are of comparatively low weight, the same conclusion may 
be drawn from Campbell's values after allowance has been made for the 
effect of the large number of relatively near stars included among his 
