218 FRAGMENTS OF SCIENCE. 



among the hills. Guided by the excellent ordnance map 

 of the region, on the Saturday morning we went up the 

 glen, and on reaching the stream called Allt Bhreac 

 Achaidh faced the hills to the west. At the watershed 

 between Glen Roy and Glen Fintaig we bore north wards, 

 struck the ridge above Glen Gluoy, came in view of its 

 road, which we persistently followed as long as it con- 

 tinued visible. It is a feature of all the roads that they 

 vanish before reaching the cols over which fell the waters 

 of the lakes which formed them. One reason doubtless 

 is that at their upper ends the lakes were shallow, and 

 incompetent on this account to raise wavelets of any 

 strength to act upon the mountain drift. A second 

 reason is that they were land-locked in the higher 

 portions and protected from the south-westerly 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 

 Eoy, and through it homewards, 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 southwards 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 obser- 

 vations of Mr. Jamieson upon this region, including the 

 mouth of Glen Trieg, are in the highest degree interest- 

 ing. 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, 



