1 
390 Transactions of the Boyal Society of South Africa. 
Section (c). — 22 cases, 12 followed by rain and 10 by dry weather ; on 
19 days wind was westerly. 
SUB-GEOUP (J). 
Section (a). — 3 cases, followed by dry weather. 
Section (b). — 8 cases, 5 followed by rain. , 
Section (c).— 13 cases, 8 followed by dry weather and 5 by rain. 
I have considered each one of these cases, and have been able to place 
them under the following heads : — 
(T) When a winter type depression is approaching from the south- 
west, and an area of high pressure is forming to the north. 
(U) When a winter type depression has passed on the previous day. 
(V) When a winter type depression has passed two days previously. 
(W) When the centre of such a depression is at L'Agulhas, but 
recovery set in elsewhere. 
(X) When a summer type depression has passed from the north to 
L'Agulhas. 
(Y) Anticyclonic movements. 
(Z) When a winter type depression impinges on an anticyclone. 
By tabulating all cases we get the following : — 
T 
U 
V 
W 
X 
Y 
Z 
Wet 
13 
2 
22 
4 
1 
2 
Dry 
1 
7 
3 
5 
17 
6 
1 
Dry 
Wet 
? 
Wet 
Dry 
Dry 
Wet 
If we now apply the results of our investigation to the rainfall returns 
of 1908 we arrive at the following : — 
Under this group there were 166 cases, 18 of which were apparently 
failures, making 10*9 per cent, (say, 11 per cent.) of the total number of 
cases. At the same time it is worth mentioning that of the 18 cases of 
failure, 14 were such as might, by exercising a little common sense, have 
been relegated to other sub-groups, and at any rate have considerably 
modified the predictions. 
