GRANITE GEOLOGICALLY’ NOTICED. 15 
concerning the character of which indeed, the most 
accomplished geologists are at variance of opinion. 
One thing however, it seems rational to conclude, 
both from the relative elevation and direction of 
one part of this curious formation, or deposit, and 
which it may not be amiss to introduce here merely 
by the way (as the precise description of the “ Bovey 
coal and clay formation” will form no part of the 
present work,) namely, that the basin thus occurring 
amid the granite hills, was filled at some time, or 
epoch, by the waters of the neighbouring Channel, 
or by a lake, whose contents were continually being 
supplied to it, from the adjoining elevated country. 
Perhaps the former supposition is the more 
consistent, involving likewise the conclusion, that 
the retreat of the sea consequent on the presumed 
geological disturbance, overwhelmed some forest 
of dicotyledonous trees, and drew them bodily to 
the occupancy of the said basin, conjointly with 
other matters, which apparently give evidence to 
this species of catastrophe. 
The region of Dartmoor is considered to extend 
in length about twenty miles from north to south, 
and in breadth to an average of ten miles. The 
chain of hills stretches from east north east to west 
south west in order to join its continuation as seen 
in Cornwall. Its centre may be said to be distant 
about twenty miles from the southern limits of the 
county. The hills rise to a considerable height, 
those on the borders being highest, the elevation 
of these above the sea reaching to nearly 2000 feet. 
The summits of these hilis present irregular, massive 
accumulations assuming extraordinary and fantastic 
forms, and called “ tors,” the blocks composing 
which are found to be arranged with some appear- 
ance of stratification ; the dip however is various. 
This assemblage of granite hills is almost generally 
bald, the rock exhibiting itself to view, and being 
