42 
Transactions of the Boyal Society of South Africa. 
paring the averages for the eleven years, 1893 to 1903 inclusive, it 
v^ill be seen that the relation is as follows : — 
As the results obtained from the rain-gauge which had been fixed tem- 
porarily near the middle Wynberg reservoir showed that great differences 
in the rainfall might be expected to exist elsewhere on the mountain, I 
decided in 1892, when I was investigating the question of the water- 
supply to Cape Town, to recommend the Town Council to provide 
additional gauges. On these being supplied, they were placed at 
various points within what has now become known as the catchment 
area to the Cape Town reservoirs, which extends to about 667 acres. 
The results obtained are, of course, applicable to a much larger portion 
of the mountain than that utilised by Cape Town. In 1900 another 
rain-gauge was erected near the existing caretaker's house. 
The duty of providing for the observing of rain-gauges erected at Disa 
Head, Kasteel Poort, Waai Kopje, and St. Michael's was relegated to 
the Meteorological Commission. The actual observations were taken 
monthly for some years by Mr. Ellerton Fry, Secretary to the Commis- 
sion, and by Mr. Gamble and myself. Afterwards other observers carried 
on the work. In 1896 the gauge at the Disa Head was observed daily 
by one of the staff employed on the reservoir works, instead of monthly 
as previously ; but the other three gauges continued to be read by an 
observer appointed by the Meteorological Commission until a few years 
ago when the reading of these was undertaken by the Cape Town Council. 
The six additional rain-gauges placed in position in 1893, together 
with that placed at the caretaker's house in 1900, were observed, under 
my direction, by one of the staff employed on the reservoir works until 
their completion in 1904. Since then the observing of these gauges has 
been done for the Cape Town Council chiefly by the caretaker, Mr. H. 
Thorsen, who had made many of the observations previous to 1904 and 
had proved himself to be a careful and painstaking observer. 
Since 1904 additional rain-gauges have been placed at various points 
on the mountain and valuable information regarding the distribution of 
the rainfall has been obtained from them, but as the gauges have not 
been observed for 10 consecutive years I do not propose to refer to them 
further in this paper. 
Table "A" shows the stations above the 2,400-foot level at which 
observations of rainfall have been taken for periods extending from 10 to 
30 years. The heights above sea-level have been taken by spirit-levelling, 
and are, with certain exceptions, given to the nearest foot. 
Disa Head 
Wynberg Watershed 
Wynberg Eeservoir (Middle) 
37-53 inches. 
58-18 „ 
55-60 „ 
