INEQUALITIES OE TEBEESTEIAL MAGNETISM. 
419 
the Vertical Force and the magnitudes of the curves in the horizontal plane; the early 
passage of node synchronizing (but with some irregularity) with the small curves in the 
horizontal plane. 
There is no appearance of any kind of cycle in these results. 
LUNO-MENSTEUAL INEQUALITIES IN THE HOEIZONTAL PLANE. 
The times of the upper and lower transits of the moon at Greenwich were computed, 
in Gottingen Time from 1848 to 1857, and in Greenwich Time from 1858 to 1863; 
and these times were laid down on the time-scales of the photographs, and the intervals 
were divided each into twelve lunar hours. For each of these hours a new measure- 
ment of ordinates was made to the pencil-curve above mentioned. Remarking that the 
lunar phenomena occur, in rapid succession, at all hours of day and night, and con- 
sequently with all orders of change of temperature, it did not appear necessary to apply 
any correction for temperature to the readings of the Horizontal-Force Photographs. 
The means being taken for every lunar day, and the first days of all the lunations 
being grouped together from 1848 to 1863, the second days being grouped together, &c., 
the means were taken for each lunation-day. The results were corrected for secular 
inequality, in the same manner as those mentioned in preceding sections (the maximum 
corrections being, at the beginning of the lunation, about -f-^g-of the annual correction, 
and at the end about — of the annual correction). The deduced lunation-inequalities 
were the following, the unit for Declination being the minute of arc, and that for 
Horizontal Force being the whole Horizontal Force : — 
Day of Lunation. 
Inequality in Declination. 
Inequality in 
Horizontal Force. 
1 
+0*04 
-0-00017 
2 
0-00 

21 
3 
+0-09 
- 
15 
4 
+0-21 
- 
6 
5 
+0-25 
- 
1 
6 
+0-24 
0 
7 
+0-19 
+ 
5 
£ 
+0-12 
+ 
9 
9 
+0-09 
+ 
9 
10 
+0-05 
+ 
6 
11 
-0-01 
+ 
5 
12 
-0*08 
+ 
2 
13 
-0*08 
2 
14 
-0-07 
- 
10 
15 
-0-07 
- 
17 
16 
-0*08 
- 
17 
17 
—0-10 
- 
8 
18 
-0-11 
+ 
6 
19 
-0-05 
+ 
16 
20 
0-00 
+ 
19 
21 
-0*05 
+ 
19 
3 K 2 
