30 
DR. S. CHAPMAN ON THE SOLAR AND LUNAR 
grouping was possible, so that the live observatories were each treated as were the 
groups in the former analysis. Equal weight was accorded to each of the five 
observatories. 
Another divergence from the course described in Part II. was that the equinoctial 
inequality was not considered (with the adopted sub-division of the data, this was 
not possible). Also the harmonics Q” n+2 in the solstitial inequality were left out of 
consideration, since the functions Q n ", as with the solar diurnal variations, repre¬ 
sented the greater part of the seasonal change, and the data hardly sufficed to 
determine the small coefficients of the remaining harmonics Q” n+2 - 
§ 13. Results of the Analysis of the Lunar Diurnal Magnetic Variation. 
The results of the harmonic analysis of the data in Tables VI. are collected in 
Table G, which includes also the values of the separated internal and external parts 
Table G.—The Spherical Harmonic Representation of the Lunar Diurnal Variations 
of West and Vertical Magnetic Force, and of the Separated External and 
Internal Fields. 
The Unit is 10~ 7 C.G.S. 
West. 
V ertical. 
External E m m . 
Internal I m n . 
n. 
m. 
A n 
• 
B m n . 
A 71 
"R n 
(a.) 
U) 
(a.) 
(b.) 
Meai 
i Solstice, 
(Summer + Wint 
er). 
1 
2 
8-8 
28-5 
- 5-0 
23 • 3 
4-3 
21-8 
4 - 5 
6-7 
9 
3 
0-4 
7-4 
■ 6-0 
4 * 6 
0-6 
4-9 
1-0 
2-5 
3 
4 
0-16 
0-42 
o-oo 
0-79 
0-09 
0-32 
0-07 
o-io 
4 
5 
0-0106 
0-0106 
0-005 
0 • 048 
0-0063 
0-0102 
0-0044 
0•0005 
Equinox, Spring and Autumn. 
1 
2 
0-4 
30-6 
- 17-5 
9-4 
3-3 
20-2 
3-7 
10-4 
- 2 
3 
-0-7 
9-0 
- 8-2 
1-5 
1-6 
5-3 
0-9 
3-6 
3 
4 
-0-03 
0-59 
- 0-31 
0-89 
0-05 
0-43 
0-02 
0-16 
4 
5 
0-009 
0-032 
- 0-009 
0-051 
0-004 
0-022 
0-005 
o-oio 
Solstitial Inequality, \ (Summer — Winter). 
1 
- 
■ 
-9 
57 
-21-4 
5'5 
-13-1 
39-8 
4-1 
17-2 
2 
2 
-3-3 
22-2 
- 6-1 
5 • 5 
- 3-2 
14-4 
-o-i 
7-8 
3 
3 
0-23 
1-68 
- 0-42 
1-02 
0-07 
HI 
0-16 
0-57 
4 
4 
0-009 
0-022 
o-oio 
0-039 
0-006 
0-016 
0-003 
0-0054 
