1862.] JAMIESON GLACIATION OF SCOTLAND. 171 



approach of two moimtains, each about 3000 feet high ; so that a 

 glacier filling the hollow of the lake would, in issuing out into Glen 

 Spean, be very much compressed by the narrowness of the gorge, and 

 therefore act more powerfully upon the rocks along which it had to 

 force its way: here then, if anywhere, we ought to expect some 

 tokens of its former presence. Accordingly we find that the tough 

 micaceous gneiss, ^11 around the outlet on both sides, has a character 

 that attracts attention even at a great distance. Although the 

 strata are highly inclined, and present their outcrop to the lake, yet, 

 notwithstanding this disadvantageous position, they have been ground 

 down into rounded flowing outlines Kke those of a feather-bed ; and 

 these domes and bosses of rock are scored in many places with long 

 rectilinear furrows, in the direction of the lake, spreading out to 

 either side like a fan as they recede from the gorge, just as might be 

 expected from the action of a glacier issuing from the narrow pass, 

 and dilating as it got out into the more open ground. One bare, flat 



Fig. 2. — View of the North Entrance to Loch Treig, from the hill on 

 the North side of Glen Spean. 



E- W. 



1. Gravel terraces, corresponding in height with the lowest of the Glen Eoy lines 

 (854 feet above the sea). 



surface of gneiss, about 30 yards long, is beautifully smoothed, and 

 covered with parallel scratches, scores, and flutings, running straight 

 from end to end. The preservation of these markings so distinctly is 

 very singular : no vegetation or covering of any kind appears to have 

 sheltered them from the weather, and yet the frosts and storms of 

 many ages have failed to wipe them out. It is right, however, to 

 mention that such cases are exceptional ; for in most places, although 

 the rock has a smooth rounded outline, yet only a few of the ruder 

 scores are visible, and often none at all. On the angle of the hill, 

 at the west side of the outlet, this worn character of the rock is very 

 marked, up to a height of more than 1000 feet above the present 



