1901-2.] Dr A. W. Roberts on Algol Variation. 
75 
observed magnitudes. An examination of these indicates that the 
period of the variable cannot be far from — 
Id. 2 Oh. 30m. 
With this period all the observations were reduced to the mean 
light period of 1901 July 1 and 2. The reduced dates are given 
in column (3). 
Arranging the dates in column (3) in order of sequence, we 
obtain the following representation of observations :■ — 
Reduced 
Date. 
Mag. 
Reduced 
Date. 
Mag. 
Reduced 
Date. 
Mag. 
1901. 
1). 
in. 
1901. 
h. 
in. 
1901. 
h. 
m. 
1 
July 1 
1 
12 
10-00 
33 
July 1 
20 
50 
io-oo 
65 
July 2 
13 
48 
10-05 
2 
2 
3 
10-00 
34 
21 
14 
9-90 
66 
14 
50 
10-25 
3 
2 
15 
10-00 
35 
22 
10 
9-90 
67 
15 
5 
10-35 
4 
2 
33 
10-00 
36 
22 
57 
io-oo 
68 
15 
5 
10-40 
5 
2 
45 
10-00 
37 
23 
10 
10-00 
69 
15 
12 
10*45 
6 
2 
45 
9-90 
38 
1 
23 
20 
io-oo 
70 
15 
15 
10-40 
7 
4 
6 
10-00 
39 
2 
1 
0 
10-00 
71 
15 
20 
10-55 
8 
5 
25 
10-00 
40 
1 
50 
9-90 
72 
15 
25 
10-60 
9 
5 
55 
10-00 
41 
2 
45 
io-oo 
73 
15 
35 
10-60 
10 
6 
25 
10-00 
42 
3 
0 
io-oo 
74 
15 
35 
10*75 
11 
6 
30 
10-00 
43 
4 
15 
io-oo 
75 
15 
40 
10-60 
12 
7 
0 
10-00 
44 
4 
52 
10-00 
76 
15 
50 
10-70 
13 
7 
44 
10-00 
45 
5 
25 
io-oo 
77 
15 
50 
10-85 
14 
9 
36 
10-00 
46 
6 
25 
10-00 
78 
15 
55 
10-75 
15 
9 
45 
10-00 
47 
6 
30 
10-00 
79 
16 
0 
10-85 
16 
10 
0 
10-10 
48 
7 
5 
io-oo 
80 
16 
5 
1075 
17 
10 
0 
10-00 
49 
7 
26 
io-oo 
81 
16 
15 
10-95 
18 
10 
58 
10-00 
50 
7 
30 
io-oo 
82 
16 
30 
10-90 
19 
13 
30 
10-00 
51 
8 
15 
io-oo 
83 
16 
30 
10-85 
20 
13 
45 
10-00 
52 
8 
42 
10-05 
84 
16 
45 
10-80 
21 
14 
30 
10-10 
53 
9 
15 
10-05 
85* 
16 
48 
(10-95) 
22 
15 
0 
10-00 
54 
9 
30 
9*90 
86 
17 
0 
10 65 
23 
15 
28 
10-00 
55 
10 
15 
io-oo 
87 
17 
0 
10-60 
24 
16 
0 
10-00 
56 
10 
30 
10-00 
88 
17 
15 
10-45 
25 
17 
0 
10-15 
57 
11 
30 
io-oo 
89* 
17 
15 
(10-68) 
26 
18 
0 
10-15 
58 
11 
42 
9-90 
90 
17 
30 
10-30 
27 
18 
30 
10-00 
59 
12 
15 
io-oo 
91 
17 
45 
10-25 
28 
19 
0 
10-05 
60 
12 
48 
10-10 
92 
18 
0 
10-15 
29 
19 
0 
10-00 
61 
13 
10 
9-90 
93 
18 
15 
10-15 
30 
20 
0 
10-00 
62 
13 
20 
10-20 
94 
19 
30 
10-05 
31 
20 
0 
10-10 
63 
13 
40 
10-10 
32 
20 
44 
10-00 
64 
2 
13 
45 
io-oo 
1 
If the foregoing observations be charted down in the form of a 
light curve, we find that, with one exception, the star remains 
constant in magnitude for 1 day 16 hours out of the full period of 
Taken too low down for accurate observations. 
