The Bainfall of South Africa. 375 
DIVISION (1). 
Section (a). — 2 cases, 1 followed by rain. 
Section (b). — One case, followed by rain. 
Section (c). — One case, followed by rain. 
Prediction for Division. — Wet weather. 
DIVISION (2). 
No cases at all. 
DIVISION (3). 
Section (a). — This happened upon 5 occasions, and only on one did 
rain follow, but this was purely abnormal. 
Section (b). — Here we have 6 cases, and dry weather followed each. 
Section (c). — This happened upon 4 occasions, 2 being followed by 
rain, but in neither case did the fall reach 0-05 in. Wind was westerly. 
Prediction for Division. — Dry weather. 
SUB-GEOUP (J). 
This is an important group ; it is not rain-bringing unless actual 
pressure is lowest at L'Agulhas. By reference to the triangle it will be 
seen that this is brought about by summer conditions, that is to say by a 
depression approaching from the north-west and passing to the north of 
the peninsula. When L'Agulhas is actually lowest the other two stations 
may have been abnormally high the day before and thus have obscured 
the actual condition, in which cases rain may be probable, but with Olan- 
william actually lowest rain is very improbable. Of course when a deep 
summer depression passes, rain may fall with a southerly wind. 
DIVISION (1). 
Section (a). — This happened upon 4 occasions with westerly winds, 
followed twice by dry weather and twice by rain. 
Prediction. — It is a very difficult condition to predict from. We 
are only certain when there are signs of a depression having moved 
across the north to the south-east, and then dry weather can safely 
be predicted. Otherwise it will be better to predict rain. 
Section (b). — This happened upon 7 occasions, wind being westerly ; 
rain followed 3 times. On the remaining 4 occasions rain fell either 
at L'Agulhas or at the Eoyal Observatory within 48 hours. 
Prediction. — Wet weather. 
