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 

 northwards, struck the ridge above Glen Gluoy, came 

 in view of its road, which we persistently followed as 

 long as it continued 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 moun- 

 tain 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 caus- 

 ing 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 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 

 DhuWi, 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 ob- 

 servations 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 



