274 ABSTRACTS OF THE MAKERSTOUN OBSERVATIONS, 1843. 
Table XII. has been formed in the following manner :—/ being the elastic force of vapour, the air being 
saturated at the mean temperature ¢ (Table I.), and /” the elastic force of the vapour actually in the air (Table 
IX.), then A, the relative humidity in the previous table, is obtained from the formula, 
Sa 
ane’. 
The values of f were obtained from the tables in the Introduction to the Greenwich Observations, 1842. 
Annual Variation of Humidity.—This has not the same period as the temperature of the air or the pres- 
sure of aqueous vapour; the minimum occurs in June, and the maximum in Winter; in the beginning of the 
year February is a maximum, and in the end of the year November is the maximum. The following are the 
means for three different classes of seasons, viz. :— 
The mean meteorological seasons, for which June, July, and August, constitute summer. 
The meteorological seasons for the year 1843, for which July, August, September, constitute summer. 
The astronomical seasons, for which May, June, July, constitute summer. 
Seasons. Mean Meteorological. Meteorological for 1843. Astronomical. 
Spring, 0°833 0-816 0-843 
Summer, 0°824 0-836 0-823 
Autumn, 0-867 0-881 0°849 
Winter, 0868 0:860 0-878 
The year 1843, 0°848. 
For the year 1843, the most regular group is that of the astronomical seasons. The greatest range of 
the means is that for the meteorological seasons of 18438, being 0-065 ; that for the astronomical group being 
0-055, and that for the mean meteorological seasons being 0:044. The range of the monthly means is 0-104. 
Extremes of the Daily Means, and the Ranges for each Month. 
Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Noy. Dec. 
Greatest, 0:935 0-985 0-929 0-913 0-991 0-973 0-935 0-952 0-956 0-978 0-992 0.965 
Least, 0-687 0-749 0-757 0-698 0-726 0-676 0-709 0-759 0-654 0-763 0-769 0-759 
Range, 0-248 0-236 0-172 0-215 0-265 0-297 0-226 0-193 0-302 0-215 0-223 0.206 
November 10th was the most humid day, and September 26th the least humid day in the year, the ratio 
to saturation for the former being 0-992, and for the latter 0-654, The total range of the daily means for the 
year 1843 is therefore 0-338. The greatest monthly range of the daily means is that for September, being 
0-302, and least monthly range is that for March, being 0-172. 
TABLE XIII.—Relative Humidity, Saturation being = 1, with reference to the Moon’s Age 
and Declination. 
Moon’s| ‘Seite | Humiaity.| 3000’ | “aea” | idit Hoon deily, | Humiast itn ‘Aeily, | Himiaie 
1 umiudity. AL = a umidity,. al. umidity. 
Age. meee, y Age. M gel ume: ll farthest ae Y°| farthest fate y 
North. North. 
9 0-843 0 12 0-833 0 11 0-852 11 
11 +854 1 10 +844 iL 12 +829 
10 -873 2 11 +847 2 9 -863 
11 -870 3 9 -841 3 11 +839 
10 *858 4 il +846 4 12 -848 
9 +853 5 10 +848 5 11 +835 
12 *849 6 9 +830 6 12 +857 
9 +855 7 12 -850 7 ll +856 
11 -880 8 10 +872 8 12 -831 
10 *862 9 11 -860 9 9 +826 
il 851 10 9 +853 10 11 -810 
10 -862 11 1l +852 11 12 861 
9 +829 12 10 +819 12 il -860 
1l +899 13 9 +823 13 12 ‘861 
This Table has been formed from Table XII. in the manner already referred to, Table X. 
