250 
Abstracts of the Makerstoun Observations, 1843. 
TABLE XXIV. — Variations of Magnetic Dip, with reference to the Moon's Age, Declination, and 
Distance from the Earth, as deduced from Tables IX. and XVI. 
Variations 
Variations 
After 
Variations 
After 
Variations 
Before 
Variations 
Before 
Variations 
Moon's 
of 
Moon's 
of 
Moon 
of 
Moon 
of 
and 
of 
and 
of 
A 
Age. 
Magnetic 
Dip. 
Age. 
Magnetic 
farthest 
Magnetic 
lartnest 
Magnetic 
after 
Magnetic 
after 
Magnetic 
Dip. 
North. 
Dip. 
North. 
Dip. 
Perigee. 
Dip. 
A nnrroo 
Din 
Days. 
• 
Days. 
> 
Days. 
> 
Days. 
' 
Days. 
> 
Davs. 
■ 
15 
0-393 
0 
0 061 
0 
0-178 
14 
0-157 
7 
0-115 
7 
0-263 
16 
0-187 
1 
0-131 
1 
0-189 
15 
0-187 
6 
0-179 
6 
0-326 
17 
0-298 
2 
0-052 
2 
0-164 
16 
0-251 
5 
0-273 
5 
0-161 
18 
0-140 
3 
0-144 
3 
0-154 
17 
0-200 
4 
0-438 
4 
0-223 
19 
0-210 
4 
0-072 
4 
0-392 
18 
0-134 
3 
0-312 
3 
0-142 
20 
0-159 
5 
0 036 
5 
0-374 
19 
0-080 
2 
0-166 
2 
0-179 
21 
0-103 
6 
0-237 
6 
0-340 
20 
0-046 
1 
0-245 
1 
0136 
22 
0-083 
7 
0-263 
7 
0-251 
21 
0-184 
P 
0-204 
A 
0-240 
23 
0-211 
8 
0-221 
8 
0-127 
22 
0-085 
1 
0-155 
1 
0-000 
24 
0-053 
9 
0-309 
9 
0-164 
23 
0143 
2 
0181 
2 
0115 
25 
0-168 
10 
0-347 
10 
0-260 
24 
0-121 
3 
0-214 
3 
0-136 
26 
0-083 
11 
0-307 
11 
0-000 
25 
0-142 
4 
0-154 
4 
0-204 
27 
0-000 
12 
0-205 
12 
0-136 
26 
0-200 
5 
0-103 
5 
0-192 
28 
0-111 
13 
0-300 
13 
0-147 
27 
0-172 
6 
0-029 
6 
0-089 
29 
0-150 
14 
0-167 
7 
0-167 
7 
0-092 
Variations op Magnetic Dip, with reference to the Moon's Age. 
A glance at the quantities in the first portion of Table XXIV. will at once shew that the dip is a maximum 
when the sun and moon are in opposition, and that it is a minimum when they are in conjunction. This result 
is perhaps more distinct in the following 
Means of Groups. 
14 days to 16 days, Full Moon, 0'-249 
17 20 ... 0'-202 
21 24 ... 0'-112 
25 28 ... 0'-090 
29 days to 1 day, New Moon, 0'T14 
2 5 ... 0'-076 
6 9 ... 0'-257 
10 13 ... 0'-290 
The maximum of dip occurs in these means rather before full moon, and there is an indication of a secondary 
maximum at the time of new moon, the minima occurring immediately before and after ; this indication of a 
secondary maximum is probably too indistinct to be trusted. 
Variations op Magnetic Dip, with reference to the Moon's Declination. 
Means of Groups. 
27 days to 1 day, Moon farthest North, 0'T80 
2 5 ... 0'-271 
6 8 ... 0'-239 
9 12 ... 0'-140 
13 days to 15 davs, Moon farthest South, 0'164 
16 19 ... 0'T66 
20 22 ... O-TOS 
23 26 ... 0'-151 
The residt from these means does not seem very distinct; on the whole, there seems to.be a maximum of 
dip about the time the moon is on the equator moving southwards, and a minimum about the time it is on the 
equator moving northwards. 
