studip:s, scientific and social 



Association; and by means of a map showing the chief 

 facts collected up to this date, kindly furnished me by 

 Mr. Percy F. Kendal, secretary of the committee, I am 

 able to give a brief sketch of the more important of the 

 phenomena, and their bearing on the extent and motion 

 of the British ice-sheet. The general reader may be 

 informed that great numbers of rocks are so local and 

 so characteristic, often being confined to a very limited 



Fig. 20.— perched block in 



OF LLANBERIS. 



district or to a single mountain, that the origin of a con- 

 siderable portion of the erratics can be ascertained with 

 the greatest certainty. 



Taking first the Shap granite, which has already been 

 mentioned as occurring at Flamborough Head, we find 

 that it has been carried northwards as far as the Solway 

 Frith, and eastward to the Eden valley in great quantity, 

 and over a wide area. Thence can be traced a line of 

 boulders of this rock over the high plateau of Stainmoor 

 into the valley of the Tees, and onward round the coast 



