An Introduction to the Study of South African Rainfall. 19 



Area. V 2 . Epoch of Maximum. 



Section XIV 24°-5 Feb. 17 Aug. 18 



VIII. E 357°-5 Mar. 3 Sept. 2 



VII. or VI. E.... 332°0 Mar. 16 Sept. 15 



V. E 292°-9 April 5 Oct. 5 



IV. E 263°-8 April 20 Oct. 19 



IX. E 356°-2 Mar. 4 Sept. 3 



VIII. W 323°-5 Mar. 21 Sept. 19 



VI. W 276°-8 April 13 Oct. 13 



V. W 307°-7 Mar. 29 Sept. 27 



IV. W 281°0 April 11 Oct. 11 



IV. E 263°-8 April 20 Oct. 19 



Section VI. W. is the one apparent exception to the orderly 

 •sequence of dates in this arrangement. Yet it is to be observed that 

 the Zwartberg Pass is in this Section. Now the monthly averages 

 for this station are obtained chiefly from casual observations of rain- 

 fall in occasional months, regular observations only having been 

 taken recently. A reference to Table 25 proves that the Zwartberg 

 numbers, because of their great relative magnitude, have considerably 

 influenced the averages of Section VI. W. The Matjesfontein 

 results, however, are not of the highest excellence. 



No very orderly scheme seems to include the angular magnitudes 

 in V 3 . They scarcely invite discussion, since much accuracy cannot 

 •be claimed for them. 



The amplitudes u x decrease in absolute magnitude, latitude for 

 latitude, from the coast inland. For example — 



« r . u x . u t . 



Section XV.... 2-494 Section XII. ... 1-815 Section X 1-285 



XIII.. 2-335 XI 1-536 VII. ... -756 



XIV... 1-702 VIII. E. -988 VI. E... -541 



IX. E. 1-201 VIII. W. -417 VI. W.. -151 



IX. W. '402 III -614 II 1-395 



III.... -614 1 2-524 



This result does not mean, as might at first sight appear, that the 

 amplitudes decrease with distance from the sea, because they actually 

 tend to increase from south to north. The following are examples: — 



Section X. . 



. 1-285 



IV. E.... 



•155 



IV. W... 



. -147 



XI... 



. 1-536 



V. E. ... 



169 



V. W. .. 



. -191 



