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CHAPTER XXIV. 



OLD BRITISH GLACIERS. 



THOSE who have closely observed the Highlands of 

 Scotland and of Cumberland, may remember that, 

 though the weather has had a powerful influence, ren- 

 dering the mountains in places rugged, jagged, and 

 cliffy, yet, notwithstanding this, their general outlines 

 are often remarkably rounded, flowing in great and 

 small mammillated curves, a configuration of ground 

 tolerably plain in the accompanying view (fig. 80), 

 especially in the rocks of the island in the foreground. 

 When we examine the valleys and plains in detail we 

 also find that the same mammillated structure frequently 

 prevails. These rounded forms are known in Switzerland 

 as roehes moutonnees, a name now in general use among 

 those who study the action of glacier-ice. Similar ice- 

 smoothed rocks strike the eye in many British valleys, 

 marked by the same kind of grooving and striation, so 

 characteristic of the rocks of Switzerland. Almost 

 every valley in the Highlands of Scotland bears them, 

 and the same is the case in Cumberland, Wales, and 

 other districts in the British Islands, and not in the 

 valleys alone, but also in the low countries as far as 

 Liverpool and the middle of England. 



Considering all these things, geologists, led many 

 years ago by Agassiz, have by degrees come to the 



