20 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 24, 



over the whole area of Dartmoor, with the exception of part of the 

 western and southern edges which the Author has not personally 

 examined. The diameters vary from 11 inches by 10 inches to 42 

 inches by 54 ; the depths from 2 inches to 9 inches, — the average 

 depth being 4^ inches ; 8 are saucer-shaped, and 27 have the bot- 

 tom flat and sides perpendicular, or slightly sloping. The follow- 

 ing Table shows the surface-diameter, depth, and description of 

 bottom of the 6 smallest and 6 largest of the 35 basins. It will be 

 observed that the increase of depth is very small, and not in pro- 

 portion to the increase of the diameter, and that 5 out of the 8 

 saucer-shaped are in the list of the 6 smallest basins. 



SIX SMALLEST BASINS. 



Diameter. Depth. 



10x11 2 ins 



12x15 2 



12x18 3 



13x14 2| 



14x18 6 



14x21 7 



Bottom. 

 Flat. 

 Saucer. 



do. 



do. 



do. 



do. 



SIX LARGEST BASINS. 



Diameter. Depth. 



39x42 5 ins. ... 



40x42 5 



40x43 3 



40x48 7 



41 X 46 5 



42x54 5 



Bottom. 

 Flat, 

 do. 

 do. 

 do. 

 do. 

 do. 



TABLE OF DEPTHS 

 OF BASINS. 



6 basins 2 inches deep. 



1 





2i 



10 





3 



3 





4 



1 





4i 



6 





5 



4 





6 



3 





7 



1 





9 



TABLE OF DIRECTION OF 

 LONGEST DIAMETER. 



In 12 basins from N. to S. 



N.N.W.— S.S.E. 



N.W.— S.E. 



N.W. by W.— S.E. by E. 



W.— E. 



W.S.W.—E.N.E. 



S.W.-~N.E. 



With respect to the origin of the Eock-basins — ^First, it is not 

 thought needful to enter upon the question whether they were 

 formed artificially by the Druids, or by others, as it is believed that 

 few if any now entertain either opinion. Secondly, as regards the 

 formation of hollows by the sea or water in motion, those causes 

 probably may be considered as similar, and the following account of 

 the " pot-holes " in the granite at the rapid before mentioned near 

 Teignhead vtdU illustrate this point : — At the top of this rapid the 

 Teign, when flooded rushes, along a nearly level surface of rock. 



