VALLEYS AND BASINS. 245 



and then let him ask himself whether, in the 

 nature of things, the water of the river could have 

 made that valley. Take the valley of the Severn, 

 from Plynlimmon to Shrewsbury, or that of the 

 Dee from Bala to Wynnestay, to say nothing of 

 the lower part of either, and it will be found 

 much nearer to the truth to say that the valley 

 is the cause of the river, than that the river is the 

 cause of the valley. If the lower parts of the 

 valleys were taken, the accumulation of debris 

 might perhaps be accounted for ; but what could 

 the Severn do toward the hewing out of the 

 Wrekin, or the Dee to that of Beeston rock ? 



In places which have more of an Alpine cha- 

 racter, the formation of the valley by the river, 

 even though that river had been running for a 

 million of years, would be, if possible, still more 

 puzzling. The Tyne and the Tiviot never could 

 have excavated their dales ; and even if they had, 

 what stream paused on its course, and altered the 

 whole system of its working, in order to find 

 basins for " the lakes ?" The Tay and its branches 

 may have cut through a pass or two, at Dunkeld, 

 Killiecrankie, and some other places ; but to sup- 

 pose that any of the valleys was altogether formed 

 by the action of the stream, is an absurdity. 

 The most conclusive instance (if any can be more 

 conclusive than another, in a case where the very 

 simplest affords demonstration) is the great valley 

 of the Scotch Highlands, from the Moray Firth on 

 the east, to Loch Linnhe on the west. There is 

 a little dyke of stone, which crosses that valley 

 somewhere near the midway between the two 

 seas ; but much of the rest is in alluvial for- 

 mations, and in the basins of lakes absolutely 



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