the same chert-gravel as the hill by Lyme. 

 From hence we had red rock and red soil, 

 without any chert-gravel to Halldown 

 [Haldon], which is a hill extending from 

 a little to the west of Exeter to near 

 Teignmouth. The upper part of this hill 

 consisted of the above-mentioned chert- 

 gravel, so that it appears that the lime- 

 stone of this country is very much mixed 

 with chert, a great deal of which seems 

 to have been reduced to gravel and de- 

 posited on strata of older formation, at a 

 great distance from the limestone where 

 it was formed. Besides, Halldown, the 

 top of which is covered with this matter, 

 is, I believe, entirely separated from the 

 rest of the country by a broad tract of the 

 red-rock country. In the cliffs between 

 Minehead and Watchett, I saw the red- 

 rock lying immediately under the blue 

 Lyas. 



In digging the tunnel for the canal in 

 Gloucestershire, they have found one or 

 more beds of clay between the strata of 



62 



