340 



THE BEITISU ISLES. 



Fi!?. 1GÔ. 



-The Fiuths of Western Scotland. 

 Sciile 1 : 2,500,000. 



BuUofLewi 



origin for mod a fertile source of discussion for years, when Agassiz, familiar with 

 the glacier phenomena of the Alps, paid a visit to Glenroy. lie at once recognised 



the ancient beaches of a lake of variable 

 height pent up by a glacier which lay 

 across the outlet of the valley. 



The firths of Western Scotland, similar 

 in all respects to the fiords of Norway, 

 also remind us of the work accomplished 

 by glaciers. On looking at a map we 

 cannot help being struck by the contrasts 

 presented by the two coasts of Scotland. 

 The eastern coast is indented by a few 

 arms of the sea, but upon the whole it is re- 

 markable for the regularity of its contour. 

 Quite different is the western, Atlantic 

 coast, between Cape Wrath and the Firth 

 of Clyde. There the irregularities in 

 the contour are innumerable. Peninsulas, 

 curiously ramified, hang to the mainland 

 by narrow necks of sand. Large islands, 

 themselves indented and cut up into 

 fragments, add to the confusion ; and in 

 this labyrinth it is only after patient 

 observation that we are able to distinguish 

 between islands and mainland, lakes and 

 arms of the sea. The natives, indeed, 

 apply the same term indifferently to lakes 

 and firths, designating both as lochs, 

 and many a promontory is named by 

 them as if it were an island. Loch Etive 

 is one of the most remarkable of these 

 sheets of water, which are at the same 

 time arms of the sea and inland lakes. The 

 sea actually penetrates up that firth for a 

 distance of 18 miles ; but its bed consists 

 of two distinct basins, placed end to end, 

 and separated by a bar, hardly covered 

 with 6 feet of water. At Connel Sound, 

 which lies at the entrance of the lower 

 basin, the tides rush past with the noise 

 of a cataract. Loch Etive attains a depth of 445 feet, whilst the depth of the sea 

 outside hardly exceeds 150 feet. Loch Fleet, another of these firths, has been 

 converted into a fresh- water lake by means of a simple wall built across its mouth.* 

 • A. Geikie, "Scenery and Geology of Scotland." 



W.of Gr 



25 Miles. 



