have attended to the ifthmus that now unites them, the more I
am perfuaded that, inftead of its having, in latter ages, been
covered with the fea, the time is yet to come when that event
will take place. I have already obferved, that the furface is
from twenty to thirty feet above the level of high water mark;
that the fand upon it, except where it is drifted into ridges, is
feldom three feet deep, and it refts upon fandftone or hard
gravel. I can now add, that ridges of blue fchiftus and granite
■rocks appear on various paTts of the furface fo elevated. Admitting
that the fandftone and the gravel, which is fcarcely pof-
fible, were the fragments of the mountains by which this plain
-is enclofed on two fides, yet neither the fehiftus nor the granite
could have been adventitious ; thefe two materials muft have
been primeval, and they abound on the moft elevated as well
as on thè lower parts of the ifthmus ; in fituations that cannot
be lefs than one hundred feet above, the level of the fea. But
i f the fea has retreated one hundred feet, in its perpendicular
height, the whole continent of Africa muft have been an ifland
at the time that the Cape promontory was an ifland. What
changes may have taken place with regard to the canals and the
inland parts of the ifthmus of Suez in the courfe of two or
three thoufand years it is not necefiary to inquire, but the
ifthmus of Suez, fo long ago, was a flat fandy ifthmus, not
much higher, nor lower, in all probability, than at the prefent
day.
I ihall now offer my reafons for fuppofing the fea to be gaining
upon the land in Southern Africa. The plain that ikirts the
Lion’s Rump, and is waihed by Table Bay and the fea, ufually
3 called
s o u t h e r n A f r i c a . 6s
Vailed t&e Green Point, is lower, much lower, than the ifthmus,
and muft confequently, at the fame time, have alfo been covered
with the fea. Now there is not one fingle appearance fo denote
that fuch has ever been the cafe. The Lion’s Hill declines in
a gentle and uninterrupted line into the plain, an appearance
which would riot have taken place Had it ever been beaten by
the billows of the ocean. This is further obvious by attending
to * c fide of the plain next to the water, where (the loofe materials
being fwept away by the violence of the furge) the rocky
ridges of fchiftus and; in piles', of granite, ruri like fo many
artificial piers*, fcmetimes to the diftance of a mile, into the fea.
The whole iho're of the penmfula is fcblloped dut in the fame
manner, demonftrating an encroachment, rather than a retreat,
o f the ocean. The two ridges alfo of the ifthmus that bound
the two bays, one to the. northward and' the dther to the Southward,
are the higheft parts of its iurfkee, andYeem to have Served
the purpofe of flopping the piogrefs, rather tfuin marking the retreat,
of the fea.
Indeed; from all the observations I have been able to make
on the fouthern coaft of Africa, l am decidedly of opinion, that
the whole of L’Aguillas Bank, ftretching from Cape Point
acrofs the entrance of Falfe Bay to the mouth of Rio' Infante
or the Great Fifli River, and to the thirtyifeventR jsiratfefof
fouthern latitude, has at one time formed a part of the continent.
The very manner in which it rounds from this extreme
point of South Africa into the main land^ the materials that
compofe it, the indentations of the coaft, all formed in one direction,
and the manner in which the fragile rocks break off
vo t. II. K perpen