134 REMARKS ON THE 



rocks, although on the plain itself, where the soil is laid 

 open, which is principally composed of limestone debris hori- 

 zontal strata of the same substance were exposed to view. Ap- 

 proaching Taunton, the road leads over some of these hills, 

 No». 1, k 2. and here it was that I met with strata highly inclined, very 

 similar in colour and aspect to some varieties of sandstone, but 

 considerably more refractory under the hammer, indicating, 

 I suspect, the commencement of the Transition series. 

 S. Vesicular Trap. I found this on the road near the house of 

 Sir Thomas Acland, a few miles north of Exeter. I saw 

 none of this in situ, though very commonly in the buildings 

 in and about Exeter. 

 4. On quitting Exeter for Moreton, the road is extremely hilly, 

 rising and descending over abrupt knolls almost all the 

 way ; these are principally formed of a soft decomposing 

 rock, in thin strata, breaking in rhomboidal fragments, and 

 very similar to the slaty clay of Werner. 

 $ f 6, 7. After passing Teign Bridge, this substance assumes a greater 

 degree of consistence, and occurs in strata nearly vertical, 

 some of which are coarser in the grain than others. These 

 were extremely difficult to break, and presented a close 

 smooth fracture, approaching to conchoidal. 

 8. The Teign is the eastern boundary of Dartmoor, and, within a 

 few hundred yards of it, and immediately beyond the strati- 

 fied rock last mentioned, Granite occurs, containing very 

 large crystals of felspar, which continues to within a short 

 distance of Tavistock, situated on the Tavy, which bounds 

 Dartmoor on the west side. 

 Here, as on the banks of the Teign, the Killas rests upon the 

 Granite. At Wheal Friendship, a mine at that time under 

 the management of Mr John Taylor, (to whose intelligence 

 I am deeply indebted for a great share of the information I 



obtained 



