312 DR. S. CHAPMAN ON THE LUNAR DIURNAL VARIATION OF THE 
Table IIIb.— Fourier Coefficients of the Lunar Diurnal Magnetic Variations, 
Reduced to the Epoch of New Moon. 
Pavlovsk. Declination West. 
The unit is (T'001 ; the small corrections mentioned in 
5. 6 have not been applied 
at this stage, cf. § 9 ; + denotes increasing transverse force. 
Season. 
Lunar 
phase. 
a\. 
b\. 
a-2 . 
K 
a's- 
b'z. 
a\. 
b\. 
r 
1 
339 
20 
249 
- 16 
95 
84 
- 18 
24 
2 
308 
- 221 
209 
- 103 
47 
19 
26 
11 
3 
333 
- 96 
180 
86 
- 20 
54 
- 11 
- 14 
Summer . . . • 
'4 
5 
157 
117 
- 106 
- 53 
95 
446 
116 
- 9 
73 
52 
-26 
-13 
70 
- 9 
5 
21 
6 
309 
-237 
291 
- 61 
150 
-57 
- 11 
- 3 
7 
174 
-209 
268 
16 
- 10 
-53 
16 
- 54 
- 
8 
180 
- 23 
395 
- 52 
75 
24 
- 36 
15 
Mean. . 
240 
- 116 
267 
- 3 
58 
5 
3 
1 
r 
1 
183 
- 150 
84 
- 3 
18 
- 23 
82 
- 13 
2 
201 
42 
4 
-166 
76 
31 
31 
24 
3 
127 
- 163 
- 78 
2 
2 
4 
22 
- 98 
Equinox . . . - 
4 
206 
7 
- 91 
117 
60 
- 43 
- 9 
9 
5 
193 
- 39 
126 
115 
- 37 
65 
100 
- 13 
6 
370 
66 
54 
34 
88 
- 13 
44 
- 20 
7 
-203 
- 137 
283 
■ 66 
_ 2 
- 89 
- 78 
- 25 
- 
8 
49 
-268 
175 
11 
6 
33 
4 
31 
Mean. . 
141 
- 80 
70 
5 
26 
- 4 
25 
- 13 
1 
- 5 
- 21 
- 60 
121 
- 35 
44 
2 
- 107 
9 
- 85 
14 
- 22 
- 17 
- 91 
32 
29 
- 58 
3 
8 
32 
- 134 
144 
39 
- 14 
17 
- 24 
Winter . . . - 
4 
- 61 
- 113 
13 
70 
- 34 
69 
37 
10 
5 
- 17 
18 
- 82 
35 
22 
49 
- 10 
- 35 
6 
- 33 
- 93 
- 17 
33 
- 91 
7 
1 
40 
7 
- 43 
-139 
5 
- 7 
- 107 
26 
69 
- 38 
1 
8 
*(183) 
- 76 
- 143 
13 
24 
- 16 
12 
62 
Mean. . 
- 34 
- 47 
- 55 
49 
- 34 
25 
20 
- 19 
* This value has been rejected in taking the mean. 
