of Devonshire and Cornwall. 109 



Bodmin, Indian Queen, Redruth, Camborne, Tregonln-hill near 

 Marazion, St. Burien, and Sennen. 



The central and highest part of the chain is granite, which extends 

 into a narrow mountain plain at the north eastern extremity, and as it 

 approaches the south-west gradually contracts into a ridge, and is 

 flanked on the right and left by grauwacke. The outline of the range 

 is not altogether continuous, several of the rounded summits which 

 compose it are separated by small vallies or ravines of various depths. 

 Thus, the Tamar, which flows to the eastward of Dartmoor forest, 

 seems quite to detach that mountain plain from the hilly country to 

 the west of Launceston ; but it is easy to see, that such a separation 

 does not exist in reality, Brown-Willy, the most elevated point 

 of the whole chain,* being in the parallel which passes directly 

 through the middle of Dartmoor forest. The whole chain may 

 be said to be formed of downs, and to be in some places interrupted, 

 but no where entirely broken off". I have little doubt, that in the 

 lower parts of the country, where the granite appears to be wanting, 

 it would be found under the rocks, which I believe cover it, what- 

 ever these may be, if wells sufficiently deep were sunk in those 

 places. 



The water-shed of the chain is to the north and south, and both 

 sides have nearly the same degree of inclination : the waters on the 

 one side run into the British, and on the other into the Bristol Chan- 

 nel. The whole range has a gradual slope towards the west, but on 

 the east the terminations are rather abrupt. The greatest breadth of 

 the chain, is a little to the east of the middle point in its longitu- 

 dinal extent. On the west it contracts into a narrow tongue of 

 land, which is almost entirely granitic. The highest part of the 



* According to the trigonometrical measurements of Lieut. Col. Mudgo, this moua- 

 tain is thirteea hundred and sixty-eight feet above the leTcl of the sea. 



