48 On the Temperature of the Sea, and its Iiifluence 
'Tadle IV. — Showing tlio Avemj^c Number of Days in eacli Month of eacli 
Wind, as found from all the Observations, 1S41 to 1S60, referred to 
8 I'Oints of the Compass. 
Average NiimbT of Days the Jlean Direction af the AVind was 
IT. 
N.E. 
E. 
S.E. 
s. 
S.W. 
W. 
N.W. 
Calm. 
January . . 
3 • 00 
3"25 
0 
-80 
2-10 
4-10 
9-75 
3-50 
1 
50 
2-80 
Februai-y . . 
2-95 
3-60 
2 
10 
1^25 
2-95 
8-00 
2-85 
1 
95 
2-GO 
March 
3-70 
4-05 
2 
•50 
2^ 10 
2-55 
7-65 
3-25 
2 
80 
2-40 
April .. 
4-00 
G'05 
3 
•45 
2-05 
2-40 
6-25 
2-55 
2 
30 
0-95 
May .. 
4-30 
7-00 
2 
•45 
1^70 
2-70 
7-55 
2-00 
1 
30 
2-00 
June .. 
3-2.5 
3-55 
2 
•15 
1^65 
2-15 
9-90 
3-65 
2 
10 
1-60 
July .. .. 
3-40 
3-70 
1 
■15 
0-55 
2-G5 
10-55 
3-95 
2 
45 
2-60 
August 
2-95 
3-00 
1 
■15 
1-30 
2-95 
10-45 
3-85 
1 
95 
3-40 
September . . 
3-GO 
5-25 
1 
85 
1-65 
2-00 
7-25 
2-55 
1 
50 
4-35 
October 
3-10 
2-.'j0 
1 
-15 
1-80 
3*40 
9-10 
4-25 
2 
05 
3-65 
November . . 
3-80 
3 ■.'5.5 
2 
-05 
2-00 
3-40 
7-70 
2-05 
2 
15 
3-30 
December .. 
2-65 
2-10 
1 
-75 
1-75 
2-95 
9-85 
3-85 
2 
05 
4-05 
Sums .. 
40-70 
47-GO 
22-55 
19-90 
34-20 
104-00 
38-30 
24 
10 
33-70 
Thus arranging these winds in the order of their frequency, 
we have the average number of days in the year for each wind 
at Greenwich, as follows : — 
From the south-west 104 days. 
,, north-east 48 „ 
,, north 41 „ 
„ west 38 „ 
south 34 „ 
„ north-west 24 „ 
,, east 22 „ 
„ south-east 20 „ 
Calna 34 „ 
It will bo seen that our prevailing winds are from the south- 
west and I'rom the north-east ; that the south-west is the pre- 
dominant wind for eight months of the year, and the north-east 
prevails from one to two months. There are, however, great 
inequalities in the persistency of these winds. Thus, in the 
vear 1856 the south-west blew for 80 days ; but in 1859 for 128 
days. Again, in 1847 the north-east wind prevailed for 23 days 
only ; but in 1S55 it continued for 74 days. The whole character 
of the weather and the climate of the year is altered by these 
variations. The activity of the wind appears also to be subject 
to the same uncertainty, for the number of calm days ranges from 
7 to 86 in different years. 
The winds from the cardinal points of the compass are 
tolerably equally distributed throughout the year, but the dry 
and cold wind in spring from the north-east is a true periodical 
