THE PARALLEL ROADS OF GLEN ROT. 107 



act upon the mountain drift. A second reason is that 

 they were land-locked in the higher portions and protected 

 from the southwesterly winds, the stillness of their waters 

 causing them to produce but a feeble impression upon the 

 mountain sides. From Glen Gluoy we passed down Glen 

 Turrit to Glen Roy, and through it homeward, thus 

 accomplishing two or three and twenty miles of rough and 

 honest work. 



Next day we thoroughly explored Glen Glaster, following 

 its two roads as far as they were visible. We reached the 

 col discovered by Mr. Milne-Home, which stands at the 

 level of the middle road of Glen Roy. Thence we crossed 

 southward over the mountain Creag Dhubh, and examined 

 the erratic blocks upon its sides, and the ridges and 

 mounds of moraine matter which cumber the lower flanks 

 of the mountain. The observations of Mr. Jamieson upon 

 this region, including the mouth of Glen Trieg, are in the 

 highest degree interesting. We entered Glen Spean, and 

 continued a search begun on the evening of our arrival at 

 Roy Bridge the search, namely, for glacier polishings 

 and markings. We did not find them copious, but they 

 are indubitable. One of the proofs most convenient for 

 reference, is a great rounded rock by the roadside, 1,000 

 yards east of the milestone marked three-quarters of a mile 

 from Roy Bridge. Farther east other cases occur, and 

 they leave no doubt upon the mind that Glen Spean was 

 at one time filled by a great glacier. To the disciplined 

 eye the aspect of the mountains is perfectly conclusive on 

 this point; and in no position can the observer more readily 

 and thoroughly convince himself of this than at the head 

 of Glen Glaster. The dominant hills here are all intensely 

 glaciated. 



But the great collecting ground of the glaciers which 

 dammed the glens and produced the parallel roads, were the 

 mountains south and west of Glen Spean. The monarch 

 of these is Ben Nevis, 4,370 feet high. The position of 

 Ben Nevis and his colleagues, in reference to the vapor- 

 laden winds of the Atlantic, is a point of the first impor- 

 tance. It is exactly similar to that of Carrantual and the 

 Macgillicuddy Reeks in the southwest of Ireland. These 

 mountains are, and were, the first to encounter the south- 

 western Atlantic winds, and the precipitation, even at 

 present, in the neighborhood of Killarney, is enormous. 



