30 Trof. H. Carvill Lewis — Comparative Studies in Glaciation. 



it is full of Scotcli granite erratics), in a north-easterly direction 

 througli Carnarvonshire, past Moel Tryfaen, and along the foot of 

 the mountains east of Menai Strait to Bangor, where it goes out 

 to sea, re-appearing further east at Conway and Colwyn. It turns 

 south-eastward at Denbiglishire, going past St. Asaph and Halkin 

 mountain. In Flintshire it turns southward and is magnificently 

 developed on the eastern side of the mountains, at an elevation of 

 over 1000 feet between Minera and Llangollen, south-west of which 

 place it enters England. There is evidence that where the ice-sheet 

 abutted against Wales, it was about 1350 feet in thickness. This 

 is analogous to the thickness of the ice-sheet in Pennsylvania, where 

 the author had previously shown that it was about 1000 feet in 

 thickness at its extreme edge and 2000 feet thick at points some 

 eight miles back from its edge. The transport of erratics coincides 

 with the direction of strise in "Wales as elsewhere, and is at right 

 angles to the terminal moraines. 



The complicated phenomena of the glaciation of England, the subject 

 of a voluminous literature and discordant views, had been of high in- 

 terest to the author, and had led him to redouble his efforts towards its 

 solution. He had found that it was possible to accurately map the 

 glaciated areas, to separate the deposits made by land-ice from those 

 due to icebergs or to torrential rivers, and to trace out a series 

 of terminal moraines both at the edge of the ice-sheet, and at the 

 edge of its confluent lobes. Perhaps the finest exhibition of a terminal 

 moraine in England is in the vicinity of EUesmere in Shropshire. 

 A great mass of drift several miles in width, and full of erratics 

 from Scotland and from Wales, is here heaped into conical hills 

 which enclose " kettleholes " and lakes, and have all the characters 

 of the "kettle moraine" of Wisconsin. Like the latter, the EUesmere 

 moraine here divides two great lobes of ice, one coming from Scotland, 

 the other from Wales. This moraine may be traced continuously from 

 EUesmere eastward through Madeley, Macclesfield, to and along the 

 western flank of the Pennine chain, marking throughout the southern 

 edge of the ice-sheet of northern England. From Macclesfield the same 

 moraine was traced northward past Stockport and Staley Bridge to 

 Burnley, and thence to Skipton in Yorkshire. North-east of Burnley 

 it is banked against the Boulsworth Hills up to a height of 1300 feet 

 in the form of mounds and hummocks. South and east of this long 

 moraine no signs of glaciation were discovered, while north and west 

 of it there is every evidence of a continuous ice-sheet covering land 

 and sea alike. The striae and the transport of boulders agree in 

 proving a southerly and south-easterly direction of ice-movement in 

 Lancashire and Cheshire. 



Erom Skipton northward the phenomena are more complicated. A 

 tongue of ice surmounted the watershed near Skipton, and protruded 

 down the valley of the Aire as far as Bingley, where its terminal 

 moraine is thrown across the valley like a great dam, reminding one of 

 similar moraine dams in several Pennsylvania valleys. A continuous 

 moraine was traced around this Aire glacier. Another greater glacier, 

 much larger than this, descended Wensleydale and reached the plain 

 of York. The most complex glacial movements in England occurred 



