200 VALLEY AND GRAVEL OF SOUTH-WEST OF ENGLAND. 
same diluvian waters, whose effects we have been tracing in the eastern, 
western, and central parts of the island. The breadth and depth of 
these valleys, from Sidmouth to Bridport, may be seen, by reference 
to the views of their termination in the coast, at Plate XXV. whilst 
their origin and extent in the interior are marked in the map at 
Plate XXVI. The highest summits of this district are also strewed 
over with rolled pebbles of quartz, that must have come from some 
distant part of the country, before the excavation of the valleys that 
now intersect it, and probably at the same time with, and by the 
agency of the same inundation from the north, which has drifted 
southwards the pebbles I have already traced over so large a portion 
of England. 
