Darwin and Pertz. — On the artificial 
Period. 
Time. 
Reading. 
Period. 
Time. 
Reading. 
97 
10.12 a.m. 
40 
99 
11.21.5a.m. 
18 
14 
37 
22 
19 
14-5 
35 
23 
22 
16 
28 
2 5 
28 
17 
23 
2 7 
40 
18 
20 
28 
46 
20 
17 
2 9*5 
52 
22 
14 
30 
57 
23-5 
24 
3 i 
62 
24 
26 
3 2 
67 
25 
3 2 
3 2 *5 
73 
27 
4 2 
34 
80 
28 
5 ° 
37-5 
83 
30 
62 
38-5 
86 
32 
72 
40 
93 
34 
84 
42 
97 
35 
93 
44 
104 
36 
100 
45 
106 
37 
103 
46 
107 
47*5 
107 5 
98 
10.39 
39-5 
44 
42 
48.5 
50 
51 
106 
105 
101 
40 
4 2 
44 
3 i 
3 i 
24 
53 
55 
5 6 
90 
77 
69 
46 
48 
49 
49-5 
50 
51 
20 
12 
8 
6 
5 
4 
4 
58 
59 
12- I 
2-5 
3 
4 
5 
62 
55 
43 
35 
30 
26 
20 
52 
5 
6, 5 
12 
54 
56 
58 
11 
15 
19 
8 
10 
12 
4 
-4 
-10 
59 
11. 2 
25 
38 
13 
14 
~ I 5 
-24 
3 
43 
15 
-29 
5 
6 
7 
5 2 
56 
60 
16 
16.5 
-34 
-38 
J 7"5 
18 
-43 
-49 
99 
11. 9 
47 
19 
-52 
10.5 
44 
I 9 , 5 
-56 
13 
38 
20 
-59 
14 
3 2 
21 
-62 
16 
26 
22 
-67 
17 
23 
23 
-73 
18 
21 
24 
-75 
J 9 
18 
24-5 
-79 
20 
!7 
26 
-87 
21 
17 
30 
-101 
Observations ceased. 
