The Climate of East London, Gape Colony. 227 



only the percentage of sky clouded, so that the relation between the 

 clouds and the rain must be more or less conjectural ; but if the 

 conditions at Kimberley may be taken as a guide, there are maxima 

 of clouds of a cirrus type in July and October, of a stratiform type 

 in April and October, and of cumulus and allied species during the 

 height of summer ; and it is entirely due to the great increase in the 

 two former in October that there is a general cloud maximum at 

 that time. 



Five years' observations of the direction from which the clouds 

 are travelling have been made. Apparently they have been referred 

 by the observers to magnetic North, and are read roughly to eight 

 points. A rough correction to true North gives the following 

 approximate Table of number of times the clouds have been observed 

 moving from specified directions in five years : — 



N. 



N.E. 



E. 



S.E. 



S. 



S.W. 



W. 



N.W. 



40 



333 



42 



19 



298 



727 



132 



18 



Some of these numbers doubtless include low-level driving mist. 

 It will be seen that the prevailing cloud currents correspond to the 

 directions of the prevailing winds (i.e., N.E. and S.W.), excepting 

 that the north-easterly cloud directions are relatively much less 

 numerous than the same wind directions.' 1 ' At Kimberley the pre- 

 vailing cloud direction is very nearly west-north-west, four years' eye 

 observations giving the following number of times seen : — 



N. 



N.E. 



E. 



S.E. 



S. 



S.W. 



w. 



N.W, 



66 



12 



4 



4 



13 



37 



253 



200 



Thus neither at East London nor at Kimberley do clouds come to 

 any extent from the south-east. Taken in conjunction with the fact 

 that inshore winds are not frequent on the south-east coast of South 

 Africa, these cloud directions furnish a strong argument against the 

 " south-easterly rain-bearing winds " myth.f 



The Table below gives particulars of the average monthly rainfall 

 at the West Bank, East London, in the 21 years, 1884-1904, 



* For these see J. R. Sutton, " The Winds of East London," Q. J. B. Met. S., 

 April, 1905. 



f In occasional thunderstorms there are south-east winds. Sparrman men- 

 tions one during a hot spell of weather, which gave him a " headach," near the 

 end of 1775. C. Stewart mentions an instance of a local thunderstorm at Port 

 Elizabeth in which the wind was S.S.E.— S. 



