in the Lodes of Dartmoor. 



403 



fitfully from remote periods (Fig. 1). The region is wild and lonely, 

 and has in a marked degree all the scenic peculiarities of the moorland 

 districts of the west of England. 



The area over which mining has been carried on is about \h square 

 miles, and is readily distinguished from the surrounding country by 

 the numerous immense open-cuts or gullies (loc. 'gunnies') which 

 have been made in it along the ' backs ' or outcrops of the more 

 important lodes ; while the heaps of veinstone debris and mine refuse 

 in the valleys combine to make it a picture of desolation. 



Fig. 1, 



Key-Map showing position of Birch Tor, Haytor, and other places 

 mentioned in the text. 



The ordinary granite of the district is coarsely porphyritic and 

 contains well-formed crystals of dark mica. Tourmaline is a common 

 • accessory mineral, and occurs as individual crystals or stellate patches, 

 or as nests of schorl-rock. 



In the lode area the ordinary granite has been invaded by 

 a multitude of dykes of granophyre, fine-grained granite, and elvan, 

 which are so poorly exposed as to be unmappable, but the extent of 

 their distribution is indicated in the figure by the shading (Fig. 2). 



The principal mines are the 'Birch Tor and Vitifer' and the 

 ' Golden Dagger', and these are, at the present time, only working in 

 a small way. Wheal Catherine, Bushdown Tin-mine, and numerous 

 other small mines have long since been abandoned. 



The following table of the total yield of tin-ore from the mines 

 during the periods for which statistics are procurable will best 

 indicate the scale upon which they have been worked : — 



