464 CAPE OF GOOD HOPE. 



rarefied by being in contact with the heated soil beneath. But little 

 difference is observed between the temperature of sunshine and shade 

 in free and open situations. 



This variation of climate is ascribed to the winds : the southeast 

 winds prevail for the most part of the year, and are warm ; these 

 are succeeded by the cold westerly winds, which invariably bring 

 fog and misty weather ; but in viewing the situation of the Cape with 

 respect to the large bodies of water flowing past it, it would seem 

 more reasonable to impute it to the warm tropical and cold polar cur- 

 rents of water, of whose existence we have given ample proof in the 

 preceding pages; for if the winds were alone to be taken into account, 

 that which comes from the southeast, in the southern hemisphere, 

 ought to produce the cold, while the west and northwesterly winds 

 should be warm. The sudden changes of temperature mentioned 

 above are merely local, and often confined within narrow limits. 



At our anchorage in the bay this occurrence was strikingly percep- 

 tible, not only by the thermometer but from the effect produced on 

 our own feelings ; while in the town, although the change could be 

 felt, still it was not so remarkable. The inhabitants assert that these 

 changes occur oftenest during the prevalence of a strong southeast 

 wind ; but my own experience leads me to believe that they take 

 place during the night, and particularly when a calm prevails, or but 

 a slight breeze is blowing, and indeed all the facts connected with it 

 would lead me to the opinion that such must be the case. Although 

 all seem to be aware of these variations of temperature, I did not 

 learn of any observations that have been taken that could be relied 

 on for accuracy. 



Thermometers in different parts of the town, of course give very 

 discordant results, and all meteorological observations ought to be 

 taken in situations as far as possible removed from the influence of 

 these changes. The southeast winds are often so violent as to prevent 

 communication between the shipping and the shore during some parts 

 of the day, and often cause damage to the small boats, or to the vessels 

 themselves. Cargoes can only be taken in or discharged with safety 

 in the morning, previous to the occurrence of these winds. 



Before concluding my remarks on the climate of the Cape, it is 

 necessary to advert to the curious effects of refraction that are often 

 observed. A strange distortion of objects is frequently seen, and even 

 at a short distance from Robben's Island the surf sometimes appears 

 to be thrown up into lofty jets of foam, or a wave is so distorted that 

 it seems rolling in high enough to submerge the whole island. 



