4o6 



ILLUSTRATIONS OF THE 



valleys were not cut out by means of it, yet 

 others may. But it muft be recolleded, that if 



feme 



m 



the coliefion and inertia of a column of rock of the 

 fame fedlion, and of the length of fixty-two miles. 

 It is not hazarding much to affirm, that no velocity 

 which could be communicated to water, not even that 

 which it could acquire by falling from an infinite height, 

 could give to it a force in any degree adequate to this 



great 



c 



fFed. 



The explanation of this valley, which appears to me 

 the mofl probable, is the following. It will be fliewn 

 hereafter, that there is good reafon to fuppofe, that, in 

 moil parts of our ifland, the relative level of the fea and 

 land has been in paft ages confiderably higher than it is 

 at pixfent. In luch circumftances, this valley may have 



T* 



been under th^ furface of the fea, the higheil part of it 

 being fcarcely loo feet above that level at prefent. 

 It may have been a kind of found, therefore, or llrait, 

 which connefted the German Sea with the Atlantic; and 

 the llrong currents, which, on account of the different 

 times of high water in thefe two feas, mull have run al- 

 ternately up and down this llrait, may have produced 

 that flatnefs of the bottom, and ftraightnefs of the fides, 



^ 



ajid that widening at the extremities, which are men- 

 tioned above. In this way, too, fome difficulties are re- 

 moved relative to Loch Nefs, which is fo deep as hard- 

 to be confiflent with the indefinite length of the 

 period of wafle that mull be afcribed to the mountains 

 on each fide of it. Its depth is faid, where greatefl, not 



