816 
ON THE DECEEASE OF EAIN 
Mean velocity of wind 
in miles per diem 
on days with raia. 
Eain at 1ft. being 
100, 
rain at 25 ft. = 
March - - - 
221 
72 
February - - 
199 
76 
April - - - 
179 
86 
December - - 
179 
83 
November - - 
170 
80 
January - - 
158 
80 
May - - - - 
149 
87 
October - - 
128 
87 
September - - 
119 
92 
August - - - 
118 
92 
June - - - 
105 
90 
July- - - - 
93 
92 
Year - - - 
152 
85 
The months being arranged in order, according to the velocity 
of the wind which prevailed on the days on which rain fell, the 
close relation between this velocity and the decrease of rain with 
elevation is seen at a glance. Thus March, the windiest month, 
shows the greatest decrease; July, the calmest month, shows a 
decrease equal to the least; while the months which occupy 
intermediate positions as regards velocity of wind, exhibit, on 
the whole, a corresponding gradation as regards decrease of rain. 
Had it been possible to set down in the table the mean velocity 
of the wind during the time that rain actually fell instead of 
the mean velocity during the whole day, the accordance between 
the two columns would, no doubt, have been closer still. 
A similar result comes out when the specially calm days of 
rain are compared with the specially windy days of rain. Thus 
Mr. Chrimes, in the article already referred to, extracting from 
his daily records for 1869 all entries of rainfall on days when 
the wind was under 75 miles per diem or above 300 miles, finds 
that on 17 “calm” days the mean percentage of rain at 26 feet 
