EXCURSION III. 95 



sides and larger ones near the middle would form an amphi- 

 theatre rather than a straight wall. We have pointed out, 

 in another Excursion, the great power of excavation due to 

 the height of fall of even a small body of water. 



The descent from the summit of Goatfell into Glen Eosa 

 and by the Rosa col must be carefully selected, as it is very 

 dangerous in some places. A few years ago a young man 

 lost his life by a fall on this descent ; and, more lately, a gen- 

 tleman from London, of literary celebrity, left behind by his 

 party, got into such a position that he could neither descend 

 nor mount, and had to remain in durance over night, till, dis- 

 covered by his answering shouts, he was released next morn- 

 ing by his friends who had gone up from Brodick to search for 

 him. For the geologist, two descents are more instructive 

 than the rest. One of these is eastwards by Maoldon and 

 the White Water, but it implies rather more fatigue than 

 most persons will consider consistent with enjoyment ; and 

 we shall therefore reserve for another Excursion an account 

 of what is to be seen on this route. The other is by the 

 plateau south-west of the mill-dam, along the boundary of 

 the granite and slate, where some fine junctions, granite 

 veins, and contorted schist, may be studied. The line of 

 junction descends the north-west front of Glen Shant Rock 

 towards the mouth of the Garbh-Alt in Rosa burn, by which 

 we passed up the opposite hill in our first excursion. On 

 the edge of the plateau, a quarter of a mile south-west of the 

 "mill-dam, a good example of a " roche moutonnee " may be 

 seen. The exposed horizontal surface is fourteen or fifteen 

 yards in extent, rounded neatly off diagonally to the laminae ; 

 the north-west front, or vertical face, is also ground off, but 

 the opposite face turned south-east retains its original form. 

 This indicates the direction of the abrading force. The 

 whole surface of this plateau ought to be carefully searched 

 for glacial striation, and other examples of " roches mou- 

 tonnees." 



