SOUTHERN AFRICA. 47 
the air to the continental mountains, where, being condensed, 
it rests on their summits in the form of a thick cloud. This 
cloud, and a low dense bank of fog on the sea, are the pre- 
cursors of a similar, but lighter, iieece on the Table Moun- 
tain, and of a strong gale of wind in Cape Town from the 
south-east. These effects may be thus accounted for : The 
condensed air on the summit of the mountains of the con- 
tinent rushes, by its superior gravity, towards the more rari- 
fied atmosphere over the isthmus, and the vapor it contains 
is there taken up and held invisible or in transparent solu- 
tion. From hence it is carried by the south-east wind to- 
wards the Table and its neighbouring mountains, where, by 
condensation from decreased temperature and concussion, 
the air is no longer capable of holding the vapor with which 
it was loaded, but is obliged to let it go. The atmosphere 
on the summit of the mountain becomes turbid, the cloud is 
shortly formed, and, hurried by the wind over the verge of 
the precipice in large fleecy volumes, rolls down the steep 
sides towards the plain, threatening raomentarily to deluge 
the town. No sooner, however, does it arrive, in its descent, 
at the point of temperature equal to that of the atmosphere 
in which it has floated over the isthmus, than it is once more 
taken up and " vanishes into air — to thin air." Every other 
part of the hemisphere shews a clear blue sky undisturbed by 
a single vapor. ^ 
The produce of the Cape peninsula is grapes, with all the 
European and many of the tropical fruits, vegetables of every 
description, barley for the use of horses, and a small quantity 
