^8S ‘ Professor Jameson’s Account of the 
DeviVs Peak. 
The most easterly mountain of the groupe we are describing, 
named the DeviVs FeaJc, agrees with Table Mountain in the 
nature and arrangement of the rocks of which it is composed. 
The lower part of the mountain exhibits strata of clay-slate ; 
these, as we ascend, are succeeded • by granite, and the upper 
parts and summit are of the usual varieties of sandstone 
General Result. 
Such, then, are the grand geognostical features of the moun- 
tains near Cape Town, and of those parts of the peninsula 
which have been examined. Are we to consider all these 
rocks as having been formed at different times, or are they 
of simultaneous formation ? The advocates for the Plutonic 
theory maintain, that the slate was first deposited in horizon- 
tal strata at the bottom of the sea, — that these strata were 
afterwards softened by heat, and raised from their original 
horizontal to their present vertical position, by the action of flu- 
id granite projected from the interior of the earth, — and that after 
these two operations Avere finished, a third took place, namely, 
that of the deposition of the sandstone over the granite and 
slate. According to this hypothesis, these rocks have been 
formed at three different periods, the slate first, next the gra- 
nite, and last of all the sandstone ; and two of the formations, 
viz. the slate and sandstone, are of aqueous origin, while the 
third or granite is of igneous formation. We consider this ex- 
planation as unsatisfactory, and are inclined to view these rocks 
as of Neptunian and simultaneous formation ; because they 
alternate with, and pass into each other, thus exhibiting the 
same general geognostical relations as occur in formations com- 
posed of sandstone and limestone, or of sandstone and gypsum. 
The junctions of the granite and gneiss, and of the sandstone 
and slate, do not present any species of veins, or varieties of in- 
termixtures, or of imbedded portions (fragments of the Hutto- 
nians), or convolutions, that do not occur at the junctions of 
universally admitted Neptunian rocks, such as limestone, clay- 
stone, gypsum, and sandstone. 
* In Plate VI, is a plan sent by Dr Adam, shewing the form and relative 
positions of the mountains near Cape Town. 
