302 ABSTRACTS OF THE MAKERSTOUN OBSERVATIONS, 1843. 
TABLE XXXIV.—Daily, Weekly, and Monthly Means of the estimated surface of the Clouds, 
the whole sky covered being 10:0. 
6-20 6-10 
The daily means in this table have been obtained from the 9 two-hourly observations by the formula given 
for the temperature, Table I. The daily means in the first week of January are the means of the 4 three-hourly 
observations. 
Annual Variation of the Surface of Cloud.—The surface of cloud is a minimum in January, the maximum 
in April, May, June, and July, the means for which four months differ little from each other ; the minimum 
surface occurs in September, after which the surface increases till December. The following are the means for 
the three groups of seasons, namely,— 
The mean meteorological seasons, for which June, July, and August, constitute Summer. 
The meteorological seasons for 1848, for which July, August, and September, 
The astronomical seasons, for which May, June, and July, 
Seasons. Mean Meteorological. Meteorological for 1843. Astronomical. 
Spring, 7:49 717 7°34 
Summer, 7°31 6°49 7°80 
Autumn, 5°85 6:41 5°93 
Winter, 6-91 6°89 6:48 
Range of Means, 1:64 1:36 1:87 
The astronomical group is the most distinct. The maximum occurs in summer and the minimum in 
autumn of that group. The greatest monthly mean is that for July, being 7°87; the least is that for Sep- 
tember, being 5-26. 
The mean for the year 1843 = 6°89. 
