1 GENERAL RESULTS OF THE MAKERSTOUN OBSERVATIONS. 
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. 
Mon tuity VARIATIONS FOR THE VERTICAL COMPONENT. 
TABLE 45.—Mean Variations of the Vertical Component of Magnetic Force free from Regular 
Secular Change. with reference to the Moon’s Age and Declination. 
Moon’s 
Age. 
d. a. 
14—16 
17—20 
21—24 
25-—28 
29— 1 
2— 5 
6— 9 
10—13 
0-00 
—0016 
| +0012 
/40013 
(+0031 
|| — 0027 
'—0010 
+0027 
0028 
0-00 
— 0062 
— 0002 
+0044 
+0015 
+0008 
+0010 
+0031 | 
— 0042 
After 
Moon 
farthest 
North. 
eee sd. 
2i— 1 
2— 5 
6— 8 || 
9—12 
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,— 
1st, That the vertical component 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 haye 
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 greatest south declination, the secondary maximum oceurs 
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 Deelina- 
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. 
TabuE 46.—Diurnal Range of the Vertical Component of Magnetic Force, with reference to the 
Moon’s Age and Declination. 
After 
Moon 
farthest 
North. 
1844. | 1845. 1843, | 1844. | 1845. Mean. 
