Dr Knox on the Climate of Southern Africa . 281 
TABLE shewing the prevailing Winds throughout each Month 
of the Year. 
Months *. 
1818, 
May, ' - 
June, 
July, - 
August, 
September, 
October, 
November, 
December, 
1819, 
January, 
February, 
March, 
April, 
Direction of the Winds, and General Remarks. 
Northerly, 28 days. 
23 
14 
21 
8 
3 
5 
3 
4 
9 
17 
135 
Southerly, 
3 days. 
2 
5 
6 
18 
21 
23 
25 
27 
21 
18 
10 
179 
West. 
As 
1 
21 
East. 
2 days. 
1 
1 
1 
2 — 
2 
2 
11 
It is not with any interested view of enhancing the value of 
these tables, that I shall here endeavour briefly to point out 
their superiority over others made in Southern Africa. Hither- 
to all Meteorological observations have been limited to Cape 
Town, or at least to the Cape peninsula, which, from its al- 
most insular situation, its lofty mountains, deep bays, and proxi- 
mity to the ocean, possesses a climate having little in common 
* It is to be remarked, that the Northerly winds include the north-west winds, 
which may perhaps be considered as the quarter from which the winter winds 
chiefly blow ; and under the head of Southerly winds are included the south-east 
winds, which blow during the summer. 
The annual range of the barometer in the above table is 0,93 ; and the range 
or fluctuation of the barometer is greater in winter than in summer, in the ratio of 
4,19 to 2,17 ; or the mean range of the six winter months is to those of summer 
as ,69 to ,36, confirming a fact long ago established by Mr Dalton with regard to 
the northern hemisphere. The connection betwixt the barometer and rain may be 
traced in the above table, a circumstance also first pointed out by the same inge- 
nious author. During the dry and cold winter months of May, June, July, Au- 
gust, September, and April, the barometer is observed to have a much higher range 
than during the warm and rainy months of October, November, December, Ja- 
nuary, February and March ; yet an inspection of several barometrical tables leads 
me to conjecture, that the changes in the barometer are more connected Math the 
temperature of the atmosphere than with rain or humidity. 
