A Preliminary Survey of the Meteorology of Kimhcrlcy. 
209 
Like Sign. 
Unlike Sign. 
82 
82 
Max. temperature in sun 
84 
87 
shade 
... 93 
78 
Min. 
... 96 
75 
93 
78 
102 
69 
... 95 
76 
86 
88 
The meaning of this summary will be understood from a single 
example : In 172 months the barometric-pressure deviation and the 
wind-resultant deviation were both positive or both negative {i.e., they had 
the same sign) 104 times ; while in the remaining 68 times the deviations 
of the two were in opposite directions {i.e., they had unlike signs). 
But on the whole it may be said that the above summary shows no 
very strong dependence of the greater number of the elements upon the 
deviation of the wind-direction resultant from its normal mean direction. 
If, however, the comparison be made month by month, a much better 
case is made out. For example, if the sunshine deviations be taken in 
periods of three months each, we get the following numbers : — 
Like Sign. Unlike Sign. 
Dec, Jan., Feb 27 times 14 times 
Mar., April, May 20 23 
June, July, Aug 24 18 
Sept., Oct., Nov..... 11 28 
That is, in December-February and in June-August the sunshine 
deviations and the azimuth deviations agree in the majority of cases. 
Now in the period December-February the mean resultant direction of 
the wind is nearly north, and in the period June-August nearly east. 
Hence in the first period an excess of sunshine will accompany a devia- 
tion to the west in the direction of the wind ; and in the second period 
there will be an excess of sunshine when the vane tends more to the 
north. Again, in the period September-November the mean resultant 
is southerly ; and in this period we get less sunshine when the deviation 
is towards the east, and more sunshine when the deviation is towards the 
west. Of the cloudiness of the sky practically the opposite may be said. 
Thus on the whole a westerly tendency in the wind indicates clearer 
skies, and an easterly tendency more cloud, and also more thunderstorms 
and more sheet-lightning. The following are the numbers for these 
three elements : — 
