1 
Geneeal Results of the Makeestoun Obseevations. 
In the mean of both years, each month, with the exception of November and December, has more observations 
greater than the monthly mean than it has less, the excess being from 5 to 13 in 100 ; in November the num- 
bers of positive and negative departures are equal, and in December the greatest difference occurs between the 
positive and negative departures, the latter being greater than the former by 16 in 100. 
Monthly Variations for the Vertical Component. 
Table 45. — Mean Variations of the Vertical Component of Magnetic Force free from Regular 
Secular Change, vs^itli reference to the Moon's Age and Declination. 
Moons 
Age. 
1843. 
1844. 
1845. 
1846. 
Mean. 
After 
Moon 
farthest 
North. 
1843. 
1844. 
1845. 
1846. 
ilean. 
d. d. 
0-00 
0-00 
0-00 
0-00 
0-00 
d. d. 
0-00 
0-00 
0-00 
0-00 
0-00 
14—16 
-0016 
-0062 
-0010 
+ 0020 
-0017 
27— 1 
+ 0053 
+ 0038 
-0005 
-0005 
+ 0020 
17—20 
+ 0012 
-0002 
+ 0012 
+ 0066 
+ 0022 
2— 5 
+ 0044 
-0008 
-0064 
+ 0010 
-0004 
21—24 
+ 0013 
+ 0044 
+ 0005 
+ 0046 
+ 0027 
6— 8 
+ 0008 
-0004 
+ 0006 
-0047 
-0009 
25—28 
+ 0031 
+ 0015 
-0027 
-0031 
-0003 
9—12 
-0018 
-0026 
+ 0001 
+ 0003 
-0010 
29— 1 
-0027 
+ 0008 
-0022 
- 0004 
-0011 
13—15 
+ 0020 
+ 0012 
+ 0011 
+ 0005 
+ 0012 
2— 5 
-0010 
+ 0010 
+ 0052 
-0057 
-0001 
16—19 
-0036 
+ 0004 
+ 0050 
-0048 
-0007 
6— 9 
+ 0027 
+ 0031 
+ 0006 
-0023 
+ 0010 
20—22 
-0048 
-0015 
+ 0025 
+ 0034 
-0001 
10—13 
-0028 
1 
-0042 
-0019 
-0016 
-0026 
23—26 
-0028 
i 
0000 
-0023 
+ 0048 
-0001 
Variations of the Daily Mean Vertical Component, with reference to the Moon's Age and Declination. — 
Table 45 has been formed from the Tables in previous volumes, and in this volume, pages 18 and 35 ; the 
means for 3 or 4 days are given, positive when greater than the mean for the year, and negative when less. 
96. The conclusions from the means of 4 years in Table 45, are, — 
\st, That the vertical compo-nent is a maximum at the quadratures, and a minimum at conjunction and 
at opposition ; the principal maximum occurs about 7 days after opposition, and the secondary maximum about 
7 days after conjunction ; the difference of the values of the two maxima is due chiefly to the year 1846, 
the only year which does not exhibit two maxima and two minima. 
2d, That the vertical component is a maximum when the moon is farthest north, and also when it is 
farthest south, and between these epochs it is a minimum ; the minima occurring when the moon is rather 
south of the equator. This result is shewn, though with some irregularity, in the numbers for each year. It 
should be remembered, in glancing over these Tables, that the number which indicates a maximum may have 
the negative sign, and that which indicates a minimum may have the positive sign ; thus, in 1845 the prin- 
cipal maximum occurs about 4 days after the moon's gi-eatest south declination, the secondai'y maximum occurs 
when the moon is farthest north, and the minima occur when the moon is about 3 days north of the equator. 
Variation of the Diurnal Range of the Vertical Component, with reference to the Moon''s Age and Declina- 
tion. — The means of groups of days given in Table 46, have been deduced from the Tables in former volumes, 
and in this volume, pages 19 and 36. 
Table 46. — Ditu'nal Range of the Vertical Component of Magnetic Force, with reference to the 
Moon's Age and Declination. 
Moon's 
Age. 
1843. 
1844. 
1845. 
1846. 
Mean. 
After 
Moon 
fartliest 
North. 
1843. 
1S44. 
1845. 
1846. 
Mean. 
d. d. 
0-00 
0-00 
0-00 
0-00 
0-00 
d. d. 
0-00 
0-00 
0-00 
(MK) 
] 0-00 
14—16 
0423 
1238 
0617 
0943 
0805 
27— 1 
0535 
0578 
0587 
0829 
0632 
17—20 
0406 
1149 
0737 
1 141 
0S5S 
2— 5 
0596 
0930 
0976 
0637 
1 0785 
21—24 
0316 
0544 
0700 
0870 
0607 
6— S 
0465 
0850 
0776 
0738 
0707 
25—28 
0502 
0446 
0658 
0568 
0543 
9—12 
0384 
0657 
06SI 
1113 
0709 
29— 1 
0374 
0540 
0610 
0731 
0564 
13—15 
0503 
0626 
04S2 
0637 
0562 
2— 5 
0395 
0463 
0627 
0640 
0531 
16—19 
03S2 
0773 
0767 
0518 
0610 
6— 9 
0678 
0688 
0710 
0S75 
073S 
20—22 
0349 
0872 
0475 
1068 
0691 
10—13 
0505 
1221 
0618 
0761 
0776 
23—26 
0426 
0946 
047S 
0952 
0700 
