MR DAVID MILNE HOME ON THE BOULDER-CLAY OF EUROPE, 689 



tions on the smoothed rocks run N. 47° E., and in the Faroe Islands* N.E. 88°, 

 in each case pointing to Scandinavia. f 



It is, therefore, highly probable that Scandinavia was, at a very early period, 

 cased in ice, and that icebergs from its glaciers flowed off towards the west and 

 south, loaded with boulders and pebbles, and leaving portions of these materials 

 on the east coasts of England and Scotland. Such, as it strikes me, is the most 

 probable explanation of the north and north-east agency which is manifested 

 on our coasts. 



At all events, no one has proposed to explain the transport of the Norwegian 

 and Swedish blocks to England by glaciers. Floating ice, in some way or other, 

 is the only imaginable agent. 



If this be a right conclusion, it adds no little weight to the supposition that 

 the north-west agency, which is so much more clearly manifested, is of a similar 

 description. 



(2.) But I freely admit that there are in England and Scotland manifestations 

 also of glacier action. Having been twice in Wales, and once in Cumberland, to 

 study the subject of these rock markings, I saw evidences of glaciers in both 

 districts. I have also seen glacial markings in the valley now occupied by Loch 

 Doon and the River Doon, in Ayrshire. I think that at Loch Skeen, and in the 

 valley north of Moffat, there are similar markings, and I cannot doubt that they 

 exist in Skye, as they were recognised there by the late Principal Forbes. 



The glacier markings, in several of the valleys where I have studied them, 

 appear to me more recent than the markings which belong to the general north- 

 west agency. In the valley of the Doon, and also in the valleys of Capel Curig 

 and Llanberis in Wales, it is not difficult to distinguish between the two sets. In 

 these valleys, the polished and striated rocks of the glacier are invariably low 

 down, and only a little way up the sides ; whilst the roches moutonnees and the 

 transported boulders, due, as I believe, to iceberg agency, are at a higher level. 

 Striations of the rocks, at these higher levels, are seldom or ever visible, unless 

 protected by boulder-clay \ from the influence of the atmosphere. 



This distinction between two sets of drift phenomena, belonging to different 

 epochs, also arrested the attention of Dr Robert Chambers. He pointed out 

 some small valleys in the bosoms of which local glaciers had left their marks. 

 " But (he adds) on the summits and high slopes of the hills, and on the portions 

 of the gneissic platform not connected with valleys, there are traces of an inde- 

 pendent and, I believe, earlier glaciation."§ He then specifies a spot where the 



* Chambers on " Faroe and Iceland," p. 28. 



f In Finmark and Northern Russia blocks have been found which have also been referred to 

 Scandinavia as their source. 



J At St Abb's Head, the rocks, about 200 feet above the sea, were found striated, when the 

 boulder-clay was removed from them, but at no other places. 



§ Edin. New Phil. Journal for 1853, vol. liv. p. 250. 



