118 EARLY MAN IN BRITAIN. [CHAP. v. 



reduced to clusters of glacier-covered islands rising from 

 the sea, which, in Lancashire and Yorkshire, was not less 

 than 300 feet above its present level. The drift of the 

 icebergs at this time was mainly in a south-easterly 

 direction, as is indicated by rocks derived from Cumber- 

 land, Westmoreland, and perhaps Scotland, and dropped, 

 as they melted, over Lancashire, Cheshire, and Shrop- 

 shire. 1 



3. The Depression continued. Climate Temperate. 



At the close of this period the climate grew warmer, 

 and banks of shingle and sand were accumulated, 

 instead of boulder clays, constituting " the Middle 

 drift sand and gravels." The glaciers disappeared, 

 and the sea beat upon an archipelago of islands, 2 

 which gradually sank beneath 'the sea to a depth of 

 from 2300 feet below their present level on the 

 flanks of Snowdon, to 1200 feet at Vale Eoyal, on 

 the road between Buxton and Macclesfield, and to 

 about 1400 feet in Scotland. And as this took place, 

 the sands and shingle gradually arrived at those alti- 

 tudes, resting on the lower boulder clay in the lower 

 and on the glaciated surface of the older rocks in the 

 higher, grounds. The climate may be inferred to have 

 been temperate, not merely from the absence of icebergs, 

 but from the presence of mollusca now living in the 

 adjacent seas. 



1 For the geography of Britain at this time, see Lyell, Antiquity of 

 Man, Fig. 43. 2 See Lyell, Antiquity, Fig. 42. 



