182 
This table shows that rainy days are most numerous, 
with a proportionate amount of rainfall, when the hori- 
zontal movement of the air, at 34 feet above the ground, is 
about five miles per hour. But the number of wet days 
diminishes as the hourly movement of the air increases, 
though the heaviest falls of rain happen as the movement 
of the air increases to an average ranging from 8 to 12 
miles per hour. The mean difference of the rainfall, 34 feet 
and 3 feet from the ground, is -032 inch. This difference is 
decreased to its minimum in calm weather, and increases to 
its maximum when the horizontal movement of the air at 
34 feet above the ground is about 16 miles per hour. 
In May last I commenced to measure the amount of rain- 
fall twice in 24 hours. The results of these measures I 
represent in the following table. 
1867. 
Rainfall 
from 
8a.m. to 8p.m. 
Rainfall 
from 
8p.m. to 8a.m. 
Difference 
between the Day 
and Night Fall. 
May 
June 
July 
August 
September 
October 
November 
December 
In. 
0932 
0-748 
3-354 
0- 779 
2-740 
2-091 
1- 281 
1-775 
In. 
0- 856 
0-602 
1- 977 
0- 849 
1- 681 
2- 009 
0- 878 
1- 991 
—0076 
—0146 
—1-377 
4-0 070 
—1-059 
—0*082 
—0-403 
4-0-216 | 
