VI. Description of the Tufinel of the Tavistock Canal, through 

 Morwel Down, in the County of Devon. 



By JOHN TAYLOR, Esq. 



TREASURER OF THE GEOLOGICAL SOCIETY. 

 [Read 6th May, 1814.] 



3-lORWEL Down is a hill, lying between the River Tamar, 

 which divides the counties of Devon and Cornwall, and the River 

 Tavy, which rises in the forest of Dartmoor ; and after passing 

 the town of Tavistock, flows on the eastern side of Morwel Down, 

 and falls into the Tamar, a few miles nearer Plymouth. 



The neck of high land separating these rivers, extends south- 

 wards from Morwel Down, and includes the parish of Beer, in 

 which are situated the Beeralstone Lead and Silver Mines, not far 

 from the point of the peninsula, the lode crossing a part of it in 

 a line from north to south. 



In pursuing the Tavy towards its source, the country rises irre- 

 gularly, and the rocks are found to consist of killas, to the borders 

 of Dartmoor; the same appearances are to be observed by taking 

 a survey of the hills situate between the eastern bank of the river 

 and the range of granite mountains which form the peculiar feature 

 of Dartmoor. True granite has not been found intermixed in the 

 central part of the range of the killas rocks of this neighbourhood, 

 in any instance within my recollection. In the valley through 



