36 
TRAVELS IN 
ftones entirely expofed. Mofl: of them are rent and falling 
afunder from their own weight : others are completely hol- 
lowed out fo as to be nothing more than a cruft or fhell ; and 
they have almoft invariably a fmall aperture on that fide of the 
flone which faces the bottom of the hill or the fea-fhore. 
Such excavated blocks of coarfe granite are very common on 
the hills of Africa, and are frequently inhabited by runaway 
flaves. 
Refling on the granite and clay is the firft horizontal ftratum 
of the Table Mountain, commencing at about five hundred 
feet above the level of the fea. It is frliceous fand-ftone of a 
dirty yellow color. Above this is a deep brown fand-ftone, 
containing calciform ores of iron, and veins of hematite run- 
ning through the folid rock. Upon this refts a mafs, of about a 
thoufand feet in height, of a whitifh-grey fhining granular 
quartz, mouldering away in many places by expofure to the 
weather, and in others paffing into fand-ftone. The fummit of 
the mountain has entirely undergone the tranfition into fand- 
ftone ; and the fkeletons of the rocks, that have hitherto refifted 
the ravages of time, are furrounded by myriads of oval-ftiaped 
and rounded pebbles of femitranfparent quartz that were once 
embedded in them. Thofe pebbles having acquired their 
rounded form by fri<fiion when the matrix, in which they are 
ftill found buried, had not aflumed. the form and confiftence of 
ftone ; and the fituation of this ftratified matrix on blocks of 
primseval granite, clearly point out a grand revolution to have 
taken place on the furface of the globe we inhabit. No organ- 
ized remains, however, of the Old World, fuch as fhells buried 
in 
