288 Paleo-Geological and Geographical Maps of the British Islands. 
selves.* This great Scandinavian ice-sheet was joined by another descending from 
the snowfields of the northern highlands, which passed right across the Minch 
and over the lower parts of the Outer Hebrides into the Atlantic. Large masses 
of ice descended in a southerly and westerly direction from the mountains of 
Perthshire and Argyleshire, as indicated by the glacial strize of the rock surfaces, 
and uniting with that of the southern uplands of Scotland,+ passed westwards 
across Cantyre and the North Channel. From the western and northern coast 
of Ireland, the ice likewise protruded seaward, soas to form with that of Scotland 
a nearly continuous sheet, as indicated by the arrows.t The whole of Ireland was 
covered by an ice-sheet, moving from an axis which stretched trom the neighbour- 
hood of Lough Corrib, in the 8. W., to Lough Neagh, inthe N. E.§ This mass was 
augmented by others of smaller size and extent, descending from the local snow- 
fields of Donegal, Galway and Mayo, Cork and Kerry, Waterford and Wicklow. 
The whole of the Irish Sea, as far south as lat. 52,° was probably filled with ice, 
coming from Ireland on the one hand, and from the south of Scotland, and the north 
of England on the other. The ice moved across Anglesea in a S.S.W. direction,| 
and along, and over, parts of the Isle of Man in a nearly parallel course. The 
course of the ice-path in Lancashire and Cheshire is indicated by the arrows.** 
The glaciers of North Wales were not of sufficient magnitude to deflect the northern 
ice from its course, but only augmented its volume. Along the banks of the 
Mersey, at Liverpool, the direction of the ice-flow was S. 35°, E.t+ The exact 
southern limit of the ice-sheet across England is not certain, but it is probable that 
it ranged across somewhere south of Welshpool, Shrewsbury, and Birmingham. 
In the centre of England the northern ice-sheet came in contact with that from 
Scandinavia, the former presence of the latter being indicated by the chalky Boulder 
Clay.{{ Itis probable the high district of the Carboniferous Limestone and Mill- 
stone Grit of Derbyshire and Lancashire was not overflowed by the ice; the 
same observation applies, with less of certainty to the ridge of the Cleveland Hills, 
and of the Chalk, north of the Wash; west of this ridge the red Boulder Clay 
of the northern ice-sheet is distributed. The direction of the ice movement along 
the north-east of England has been noted by Sir A. Ramsay,$$ and that of the 
* Trans. Roy. Soc. Edin., vol. xxx., p. 217. 
t J. Geikie, ‘Great Ice Age,” Plate xy. and text. 
t Rey. M. Close, Journ. Roy. Geol. Soc. Ireland, vol. i. 
§ “ Phys. Geol. and Geog. of Ireland,” p. 225, and map, p. 211. 
|| Sir A. Ramsay, “ Phys. Geog. of Great Britain,” 4th edt., p. 403. 
qf Rev. J. Cumming. 
*“'R. H. Tiddeman, Quart. Journ. Geol. Soc., vol. xxviii. 490 ; and J. G. Goodchild, Iid., vol. xxxi.. 
p- 09. 
+t G. H. Morton, Rep. Brit. Assoc. 1870. 
tt 8. V. Wood, Quart. Journ. Geol. Soc., vols. xxiii. and xxxvi. 
§§ Supra cit. 
