34 
DR. S. CHAPMAN ON THE SOLAR AND LUNAR 
two sets of determinations is the same, and although there are phase differences the 
amplitudes are closely similar. 
We now pass on to consider the connection between the external and internal 
fields determined from the solar and lunar diurnal variations, the material being- the 
results contained in Tables F and G. 
Part IV.— The Connection Between the External and Internal Magnetic 
Variation Fields. 
§ 15. The Observed Values of the Amplitude Ratios and Phase Differences. 
In the present section the subject of discussion will be the relation between the 
external and internal magnetic variation fields, as measured by the amplitude ratio 
and the phase difference e,,”— i„". AVe shall not be concerned, for the time 
being, with the actual values of E m " and e m ”. The values of the amplitude ratios and 
phase differences for the solar diurnal magnetic variation are given in Table I. The 
values of E,„”, I m “, e m ", i„” and the amplitude ratios and phase differences for the lunar 
diurnal variation, calculated from Table C, are given in Table J (cf the first six columns). 
Table I.—Comparison of the External and Internal Solar Diurnal Magnetic 
Variation Fields. 
Sunspot maximum, 1905. 
Sunspot minimum, 1902. 
Mean. 
n. 
rn. 
Mean equinox. 
Mean solstice. 
Mean equinox. 
Mean solstice. 
Em 71 Am 1 - 
pH i n 
i-7/i • 
TH n/J 'll p n _-j n 
TT n/J n 
in / • 
p n _ i n 
p n _ i 7i 
bd 
7-i 
i 
* 
1 
9 
2-9 
- 5 
o 
2-8 - 3 
2-7 
1 -23 
3-0 
o 
-20 
O 
2-8 -13 
2 
3 
2-4 
- 18 
2-3 -19 
2-0 
- 17 
2 * 2 
-18 
2-2 -18 
3 
4 
2-4 
-21 
2-7 -20 
2-5 
-21 
2-4 
-21 
2-5 -21 
4 
5 
2 * 2 
-23 
2-3 , -15 
2-9 
-30 
3-2 
-24 
2-7 1 -23 
Mean 
2-5 
- 17 
2-5 -14 
2-5 
-23 
2-7 
-21 
2-55 -19 . 
Mean of 1902 and 1905. 
Qn n - 
Q ,l »l + 2- 
| (Summer 
2 (Spring 
4 (Summer 
A (Spring 
— 
Winter). 
- Autumn). 
— 
Winter). 
— 
Winter). 
1 
1,3 
2*5 
0 
- 7 
o 
2-1 - 1 
2-7 
o 
+ 3 
3-0 
o 
4 
2 
2,4 
2-3 
- 8 
2-6 + 2 
2-0 
-31 
0-5 
+ 78 
3 
3,5 
2-0 
-32 
2-2 -13 
1-1 
+ 42 
4-2 
- 15 
4 
4,6 
1*7 
- 30 
1-7 -19 
3-0 
+ 65 
0-4 
+ 12 
Mean 
2-1 
- 19 
2-2 - 8 
