128 
This table, like the one I communicated to the Section 
last year, seems to show that the night fall is mostly in 
excess in the coldest months of the year. 
I now submit a new set of tables relating to wind and 
rainfall. The elements from which the tables respecting 
the wind are deduced have been obtained from a self- 
registering pressure anemometer made by Mr. Oxley, and 
Dr. Kobinson’s anemometer. Very curious though not 
unexpected results are found on an examination of these 
tables. The first table represents the mean daily direction 
of the wind grouped under eight points of the compass. 
The amounts of horizontal movement of the air in miles for 
each day are grouped under the months of the year, and 
placed under the mean direction whence the movement 
came, and so arranged as to indicate whether the mean 
direction has been against or with the sun’s course. The 
direction of the wind is said to be against the sun’s course 
on the west side of the compass when the mean direction of 
one day is nearer the south point than it was on a previous 
day ; and with the sun’s course on the same side of the 
compass when the mean direction is nearer the north point 
than on the previous day. The reverse of these directions 
happens on the east side of the compass. The results of 
these directions appear at the foot of the respective columns, 
and they show that when the wind is blowing on the west 
side of the compass with the sun’s course, the horizontal 
movement of the air is greater than when it is blowing 
against the sun’s course. But when the wind is blowing on 
the east side of the compass with the sun’s course, the hori- 
zontal movement of the air is less than when it is blowing 
against the sun’s course. But the monthly results show 
that in every month of the year, excepting May, there has 
been an excess of horizontal movement of the air with the 
sun’s course ; hence that the westerty winds greatly prevail 
over the easterly ones. 
