ASTRONOMY: C. D. PERRINE 
73 
spectra, the evidence from these two sources is not of as great weight as the 
preceding. It is, nevertheless, quite definite. 
Of the 19 Harvard composite stars, two are somewhat uncertain as to the 
difference of spectral class, both being of early type. Of the remainder, the 
one having the largest proper motion (0".15) has the fainter component of the 
later type. The remaining 16 all have very small proper motions. Of these, 
5 have the fainter component of later type and 11 of earlier type. All of 
TABLE 2 
Fainter Component of Earlier Type 
MAGNITUDE 
A 
SPECTRAL CLASS 
BRIGHTER 
s 
COMPONENT 
MAGNITUDE 
Brighter 
Fainter 
6.2 
1.2 
Go 
A 
0'018 
2:9 
4.3 
0.9 
A 3 
A 
42 
2.6 
2.3 
2.8 
K 0 
A 
70 
10.7 
5.0 
1.4 
G 5 
B? 
34 
6.9 
5.5 
1.2 
G 
A 3 
29 
3.0 
5.9 
1.1 
A 0 
B 9 
27 
28.9 
5.8 
1.2 
G 
A 
47 
0.4 
5.4 
3.1 
K 
A 
7 
2.3 
3.9 
1.9 
K 0 
G 
97 
13.3 
6.4 
0.5 
G 
Ao 
rv 2 
41 
63.4 
4.2 
2.4 
G 5 
A 2 
54 
30.6 
5.2 
1.5 
K 0 
A 3 
17 
20.6 
5.3 
0.5 
A 2 
A 
33 
21.6 
2.7 
2.4 
K 0 
A 
49 
2.8 
3.5 
4.5 
K 0 
G 0 
155 
104.8 
1.2 
5.8 
Ma 
A 
34 
3.2 
6.4 
1.1 
K 
F 5 
48 
111.2 
6.1 
1.7 
G 
A 
11 
45.5 
5.6 
1.2 
F 5 
A 
13 
0.6 
7.1 
1.0 
G 
A 
42 
4.1 
6.0 
1.5 
F 5 
A 2 
18 
15.0 
3.2 
2.1 
K 
B 9 
9 
34.7 
5.6 
3.3 
K 0 
A 
34 
19.8 
6.5 
1.1 
F 
A 
Small 
1.2 
5.7 
2.2 
Go 
A 
20 
89.9 
6.1 
0. 
G 5 
A 2 
25 
23.0 
3.9 
3.2 
K 
B 8 
2 
107.1 
3.3 
2.8 
G 0 
A 0 
28 
205.2 
the most strongly marked spectral contrasts have the fainter components of 
earlier type and all but one of these 11 are well marked in respect to spectral 
contrasts. 
Of the 62 stars of Campbell's Catalog, 30 belong to types O and B and 23 
to type A. It is reasonably certain, therefore, that all of the O and B stars 
are distant and the probability is strong that most of the 23 stars of type A 
