254 
Abstracts of the Makerstoun Observations, 1843. 
Variations of the Total Magnetic Force with reference to the Moon's Declination. 
Means of Groups. 
27 days to 1 day, Moon farthest North, 0-000101 13 days to 15 days, Moon farthest South, 0-000072 
2 5 ... 0-000084 16 19 ... 0-000022 
6 8 ... 0-000058 20 22 ... 0-000017 
9 12 ... 0-000041 23 26 ... 0-000031 
There seem, therefore, to be maxima of the total magnetic force when the moon has its greatest north and 
south declinations, and minima about the time when the moon is on the equator. The principal maximum occurs 
when the moon has its greatest north declination, and the principal minimum when it is on the equator moving 
northwards ; the secondary maximum and minimum are not shewn so distinctly. 
Variations of the Total Magnetic Force with reference to the Moon's Distance from 
the Earth. 
Means of Groups. 
6 days after Apogee to 6 days before Perigee, 0-000103 6 days after Perigee to 6 days after Apogee, 0-000041 
5 days to 2 days before Perigee, 0-000081 5 days to 2 days before Apogee, 0-000037 
1 day before to 1 day after Perigee, 0-000064 1 day before to 1 day after Apogee, 0-000024 
2 days to 5 days after Perigee, 0-000082 2 days to 5 days after Apogee, 0-000069 
Extreme Positions. 
TABLE XXVIII. — Differences of the Extreme Readings of the Three Magnetometers from the 
Monthly Means for the Hours at which they occurred, for each Month in 1843, as deduced from 
the Nine Daily Observations, together with the Ranges of the Three Magnetic Elements in each 
Month. 
Westerly Declination. 
Bifilar Magnetometer. 
Balance Magnetometer. 
Ranges. 
Month. 
Greater than 
Mean. 
Less than 
Mean. 
Reading greater 
than Mean. 
Reading 
than Me 
Less 
in. 
Reading greater 
than Mean. 
Reading less 
than Mean. 
Decli- 
nation. 
Horizontal 
component 
Vertical 
component 
1843. 
Jan. 
d. 
16 
h. 
2 
+ 4-15 
d. 
23 
h. 
8 
4-64 
d. 
16 
h. 
6 
Sc. Dif. 
+ 9-4 
d. 
28 
h. 
8 
Sc 
. Div. 
12-9 
d. 
28 
h. 
6 
Mic. Div. 
+ 85-0 
d. 
27 
h. 
18 
Mic. Dir. 
- 44-5 
12-70 
000239 
0-00133 
Feb. 
24 
4 
+ 15-95 
6 
10 
36-75 
12 
20 
+ 10-0 
14 
10 
14-5 
24 
S 
+ 123-9 
13 
20 
- 47-8 
59-29 
•00267 
•00171 
Mar. 
7 
4 
+ 10!) 1 
29 
10 
15-41 
18 
6 
+ 19-4 
7 
8 
24-8 
7 
8 
+ 292-7 
31 
0 
- 52-2 
33-02 
•00474 
•00335 
Apr. 
6 
2 
+ 10-79 
6 
10 
12-85 
5 
6 
+ 43-9 
5 
10 
68-8 
5 
6 
+ 344-0 
5 
20 
-105-4 
33-38 
•01265 
•00152 
May 
26 
2 
+ 4-22 
6 
10 
18-44 
10 
6 
+ 18-4 
6 
10 
79-1 
15 
10 
+ 79-S 
6 
10 
- 257-2 
29-84 
•01069 
•00303 
June 
30 
2 
+ 7-96 
29 
20 
6-50 
30 
6 
+ 13-3 
11 
22 
10-6 
13 
6 
+ 53-7 
4 
IS 
- 38-6 
25-60 
•00474 
•110097 
July 
25 
2 
+ 5-55 
24 
10 
26-31 
25 
4 
+ 96-2 
24 
22 
42-0 
25 
4 
+ 246-1 
0 
IS 
- 56-7 
40-48 
■01627 
00291 
Aug. 
22 
2 
+ 4-23 
I 
6 
8-79 
4 
6 
4-22-6 
8 
IS 
36-8 
4 
6 
+ 116-1 
8 
IS 
-1530 
19-86 
■00744 
•00268 
Sept. 
1 
20 
+ 13-00 
18 
10 
9-11 
23 
6 
+ 17-1 
IS 
22 
16-4 
5 
6 
+ 51-5 
27 
18 
- 46-2 
24-90 
•00508 
•00115 
Oct. 
:') 
0 
+ 6-16 
26 
10 
17-63 
16 
10 
+ 38-1 
4 
22 
9-0 
26 
6 
+ 90-8 
4 
IS 
- 63-8 
31-39 
•00617 
■00165 
N«>\ . 
6 
0 
+ 5-89 
3 
8 
4-22 
24 
2 
+ 10-8 
3 
0 
10-3 
3 
2 
+ 32-6 
2 
IS 
- 20-3 
14-20 
•00335 
00068 
Dec. 
12 
2 
+ 5-45 
1 1 
8 
11-22 
8 
20 
+ 151 
8 
10 
18-6 
8 
8 
+ 94-5 
10 
18 
- 46-2 
J 21-S2 
•00412 
• 00153 
