Solar Energy in Relation to Ice. 153 



marked case was that where the ice from the east of Scotland 

 encountered the ice from Scandinavia. There can be no doubt 

 that, near the climax of the Glacial Period, the ice originat- 

 ing within the mountains of Scandinavia did, for some time, 

 extend far across the lowland area now occupied by the 

 North Sea. This is shown not only by the occurrence of 

 many boulders of undoubted Scandinavian origin in the 

 glacial deposits of the North of England, but also by the 

 strongly-marked deflection of the glacial markings on the 

 eastern .side of Scotland, as will be seen from a study of any 

 good map of glacial markings, such as the one in James 

 Geikie's "Great Ice Age," or in Sir Archibald Geikie's 

 charming " Scenery of Scotland." It appears to me that the 

 deflection referred to need not have been caused by ice of 

 foreign origin which had actually reached that part, but may 

 well have been produced by the action of an ice-barrier 

 emanating from Scandinavia, and which met the Scottish ice 

 somewhere to the east of our present coast, and then simply 

 dammed the local ice back, so that it was compelled to move 

 in directions contrary to what it would have taken if the 

 barrier had not been there. It is to this damming-back by 

 the ice from Scandinavia that I should be disposed to 

 attribute the westward movement of the ice that lay to the 

 east of the watershed in the North -West Highlands. Prob- 

 ably only the higher strata of the ice would so move. In the 

 explanation of the origin of boulder clay by englacial means 

 that I put forward in 1874,^ the boulders and the materials 

 of the boulder clay were assumed to have been transported 

 within, and not heneath, the ice, and to have been left as a 

 sediment when the ice melted. As this view has now met 

 with general adoption, there ought to be no difficulty in 

 explaining the westerly transportal of boulders in the 

 present case. 



The chief reason, however, why this glacial feature of the 

 North- Western Highlands has been r jl'erred to is to emphasise 

 the fact that, in order to produce such an effect as that noted, 

 the Scandinavian ice need not after all have been so very 



1 Geol. Mag., Nov. 1874, "On Drift." 



