Relative Humidity. 
275 
Humidity with reference to the Moon's Age. — The following means of groups indicate a minimum of hu- 
midity about four days before full Moon, and a maximum about four days before new Moon. 
12 days till 18 days, Full Moon, 0-845 
15 22 ... 0-857 
19 26 ... 0-859 
23 29 ... 0-864 
27 days till 3 days, New Moon, 0-851 
0 7 ... 0-842 
4 11 ... 0-851 
8 14 ... 0-844 
Humidity with reference to the Moon's Declination. — The following means of groups indicate a maximum 
of humidity about four days before the Moon attains its greatest north declination, and a minimum about four 
davs before it attains its greatest south declination. 
25 days till 3 days, Moon farthest North, 0-847 
0 6 ... 0-846 
4 10 ... 0-838 
7 13 ... 0-844 
11 days till 17 days, Moon farthest South, 0-849 
14 20 ... 0-842 
18 24 ... 0-857 
21 27 ... 0-861 
TABLE XIV. — Hourly Means of the Relative Humidity for each Month and Quarter in 1843. 
Saturation being = 1. 
Period. 
18 h . 
20 h . 
22 h . 
0\ 
2 h . 
4 h . 
6\ 
8 h . 
10\ 
Mean. 
Range. 
January 
0-85S 
0-869 
0-850 
0-814 
0-811 
0-837 
0-860 
0-841 
0-842 
0-844 
0-058 
February 
•899 
•889 
•863 
•815 
• 811 
•830 
•876 
•891 
•920 
•877 
•109 
March 
•914 
•908 
•860 
•803 
•766 
•758 
•813 
•881 
■886 
•857 
•156 
April 
•895 
•855 
•774 
•708 
•692 
•694 
•757 
•839 
•850 
•807 
•203 
May 
•930 
•883 
•811 
•766 
•735 
■759 
•768 
•840 
•903 
•845 
•195 
June 
•873 
•821 
•766 
•727 
•737 
■720 
•740 
•768 
•857 
•800 
•153 
July 
•908 
•849 
•768 
•740 
•718 
•723 
■779 
•838 
•881 
•824 
•190 
August 
•947 
•907 
•823 
•764 
•720 
•711 
•775 
•887 
•930 
•857 
•236 
September 
•936 
•933 
•850 
•746 
•693 
•676 
•771 
•893 
•931 
•852 
•260 
October 
•910 
•916 
•837 
•783 
•746 
•766 
•848 
•890 
•891 
•857 
•170 
November 
•927 
•929 
•909 
•846 
•838 
•845 
•906 
•924 
•923 
•902 
•091 
December 
•886 
•886 
•844 
•860 
•848 
•866 
•877 
•875 
•881 
•873 
•042 
Spring 
•913 
•882 
•815 
•759 
•731 
•737 
•779 
•853 
•880 
•836 
•182 
Summer 
•909 
•859 
•786 
•744 
•725 
•718 
•765 
•831 
•889 
•827 
•191 
Autumn 
•924 
•926 
•865 
•792 
•759 
•762 
•842 
•902 
•915 
•870 
•167 
Winter 
•881 
•881 
•852 
•830 
•823 
•844 
•871 
•869 
•881 
•865 
•058 
The Year 
•907 
•887 
•830 
•781 
•760 
•765 
•814 
•864 
•891 
•850 
•147 
Table XIV. has been formed from Tables III. and VIII. by means of the formula given after Table XII. 
Diurnal Variation of the Relative Humidity. — The maximum humidity occurs between 9 p.m. and 5 a.m. 
The minimum occurs as early as 10 h 30 m a.m. in December, and as late as 2 h 30 m in March and September. 
The progression is regular in each month, with the exceptions of June and December ; a secondary maximum 
occurs in the former at l h 10 m p.m., and in the latter at ll h 10 m a.m., the minima occurring two hours before 
and after. The following are the periods of minima for the four meteorological seasons, and also for the four 
astronomical seasons : — 
Meteorological Seasons. Astronomical Seasons. 
Spring, l h 40 m p.m. Spring, 2 h 0 m p.m. Makerstoun mean time. 
Summer, 2 h 30 m p.m. Summer, l h 25 m p.m 
Autumn, 2 h 10 m p.m. Autumn, 2 h 20 m p.m 
Winter, 0 h 30™ p.m. Winter, 0 h 50 m p.m 
The year, l h 50 m . 
