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THE EAINFALL OF SOUTH AFEICA. THE POSSIBILITY 
OF PEEDICTION OVEE THE SOUTH-WEST. 
By a. G. Howaed, M.S. A. 
(Communicated by L. Peeinguey.) 
(Eead May 19, 1909.) 
If we take Clanwilliam, the Eoyal Observatory, and L'Agulhas, we 
have a triangle covering the south-west of Cape Colony, and as weather 
over that portion of South Africa forms a prelude to that all along the 
coast, it is evident that if we can ascertain beforehand what is in store 
within this triangle, we have the key to forecasting for the whole of the 
Colony. The position of L'Agulhas is one of great importance, and the 
movements of the barometer there in relation to those at the other two 
stations will indicate to a great extent what further atmospheric movements 
are impending. 
By the kind courtesy of the Acting Secretary to the Meteorological 
Commission, during the absence of the Secretary in England, I have had 
access to the records of the morning simultaneous readings for several 
years, and have arranged them in groups, wherein each triad of readings 
bear a relationship to each other. 
As I consider Cape L'Agulhas of such importance, I have taken into 
consideration the wind there, without reference to that at the other two 
stations ; in fact, the wind records at these two stations are not of much 
value, especially when taken at 8.30 a.m. 
In registering the rainfall I have given that recorded at the Eoyal 
Observatory, but inasmuch as the indications refer to a wide field, it may 
be that in some instances rain fell away from that station, and although 
the forecast would appear to be a failure, still, had records from all places 
in and around the triangle been taken, we might have seen a verification 
of the forecast. 
In an investigation of this kind the first question to be asked is : 
" What amount of rainfall should be considered as constituting wet 
weather?" I should say that anything beyond 0'05 of an inch would 
