CAPE OF GOOD HOPE. 
437 
temperature throughout the year is 67j°. 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. 
2 M 2 
