The Bainfall on Table Mountain. 
43 
Of the whole of the stations from which records have been received 
for 10 years or more, at the end of 1911 only two had been in existence 
for 30 consecutive years, namely, Disa Head and Waai Kopje; but another 
two had been in existence for 27 years, namely, Kasteel Poort and St. 
Michael's. Comparing the averages for Disa Head and Waai Kopje for 
the 30 years with those of the same stations for the 27 years it will be 
seen that the differences are inconsiderable, thus : — 
No. of 
Years. 
Average Yearly Rainfall in Inches. 
Period. 
Disa 
Head. 
Waai 
Kopje. 
St. 
Michael's. 
Kasteel 
Poort. 
30 
1882-1911 
39-24 
66-83 
27 
1885-1911 
39-44 
67-63 
61-64 
75-24 
It may therefore be assumed for all practicable purposes that the 
averages at Kasteel Poort and St. Michael's w^ould have been approxi- 
mately the same for 30 years as for 27 years. 
Continuing the comparison of the records for shorter periods, I would 
direct attention to Table B," where the averages for all the stations in 
existence for periods of 30, 27, 19, 18, and 12 years previous to 1912 are 
tabulated, as well as the averages for the 11 years 1893 to 1903 inclusive 
and the 10 years 1894 to 1904 inclusive. Taking the averages for the 
11 years for the three stations, Waai Kopje, St. Michael's, and Kasteel 
Poort, and comparing them with the averages for the same stations for 
27 years : — 
No. of 
Period. 
Average Yearly Rainfall in 
Inches. 
Years. 
Waai Kopje. 
St. Michael's. 
Kasteel Poort. 
27 
1885-1911 
67-63 
75-24 
61-64 
11 
1893-1903 
68-03 
75-54 
61-09 
It will be seen that the maximum difference between the averages for 
the two periods is only 0*55 inch, which is scarcely appreciable. The 
difference between the averages of the Waai Kopje gauge for 11 and 
