234 VALLEYS AND BASINS. 



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 accumu- 

 lation of debris might perhaps be accounted for ; but 

 what could the Severn do towards the hewing out of 

 the Wrekin, or the Dee to that of Beeston rock 1 



In places which have more of an alpine character, 

 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 work- 

 ing, 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 suppose 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 dike of stone, which crosses that 

 valley somewhere near the midway between the 

 two seas ; but much of the rest is in alluvial forma- 

 tions, and in the basins of lakes absolutely lower 

 than the bottom of the adjoining sea, to which the 

 Ness, the largest river of that singular valley, runs. 



Nor are the proofs confined to the mere forms of 

 surfaces, for they are to be found in the very rocks 

 themselves. Where the schistose, or stratified rocks 

 meet the granular ones, they are twisted and bent in 

 all directions, as they would have been had they been 

 upheaved by some action from below ; and at many of 

 the lines of junction one of the rocks is melted as if 



