CAPE OF GOOD HOPE. 437 



temperature throughout the year is G7^°. The extremes vary 10° 

 above and as much below the mean. It is classed by its inhabitants 

 under the warm and equable climates ; yet, notwithstanding, in many 

 situations, it is extremely variable : the thermometer will fluctuate ten 

 degrees in as many minutes, producing an unpleasant sensation of 

 cold ; this is owing to the chilly winds that sweep down from the 

 Table Mountain in blasts, to equalize the density of the atmosphere 

 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 winterly 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 rea- 

 sonable to impute it to the warm tropical and cold polar currents 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. 

 2M2 



