454 THE ICE AGE IN NORTH AMERICA. 



The work begun by Professor Lewis was subsequently car- 

 ried on by The Northwest of England Bowlder Committee, of 

 which Professor Percy F. Kendall was for some years the 

 efficient chairman. The final conclusion from these and other 

 investigations are thus briefly summarized by Dr. F. W. 

 Harmer,* as follows: 



"Most glaciologists believe that this country was invaded 

 by ice, on the east from the German Ocean, and on the west 

 from the Irish Sea. Crossing the Lincolnshire Wolds, ice 

 from the North Sea, augmented, I think, by that of an 

 inland glacier from the Vale of York, traveled towards the 

 plain of the lower Witham and the Fenland, whence it over- 

 spread a large tract of country to the east, the south and 

 the west. To the east it reached the Suffolk coast, to the 

 south nearly to the valley of the Thames, while to the west 

 it filled those of the Welland, the Nene, and the Ouse, over- 

 riding also the highland intervening. 



"Another branch of the northern glacier, keeping to the 

 west of the Lincoln ridge, and reinforced by the North-Sea 

 ice, moved towards Doncaster and up the Trent basin to 

 the vicinity of Derbe, where it met the Derwent glacier, and 

 thence crept southward along the valley of the Soar into 

 Warwickshire. 



"On the west, the Cheshire plain was invaded by ice from 

 the Irish S3a which, diverting the glaciers descending from 

 the mountains of North Wales towards the south, carried 

 vast numbers of Scottish and Lake-District erratics into the 

 northern part of the basin of the lower Severn, heaping 

 them also upon Cannock Chase, and upon the high land near 

 Wolverhampton. 



"In South Wales, Dr. Strahan and his colleagues have 

 shown that ice descended in great thickness from the Breck- 

 nock Beacons towards the Bristol Channel, reaching the 

 shores of the latter near Swansea, filling the Neath and Taff 

 valleys to overflowing, and rising to a great height on the 

 intervening hills. 



* a Quarterly Journal of the Geological Society" for November 1907, 

 vol. lxiii, p. 471-474. 



