404 



ILLUSTRATIONS OF THE 



burgh. The Pentland Hills form a double ridge, 

 feparated by a fmall longitudinal valley, that 

 runs from N. E. to S. W., the water of which 

 ifTues from an opening almoft in the middle, 

 and directed towards the fouth. This, there- 

 fore, is not the work of any great torrent, which 

 overwhelmed the country ; for no one direc- 

 tion, which it is poffible to affign to fuch a tor- 



rent, will afford an expl 

 valley and its outlet *. , 



both of the 



362. They 



* In Scotland there Is one valley, of a kind that I be- 

 lieve is extremely rare in any part of the world, in ac- 

 counting for which, the hypothecs of a torrent or debacle 

 might, if any where, be employed to advantage. This is 

 the valley which extends acrofs the ifland, from Invernefs 

 to Fort-William, or from fea to fea, being open at both 

 ends, and very little elevated in the middle. It is nearly 

 ftraight,andof a veryuniform breadthjCxcept that towards 

 each end it widens conliderablj. The bottom, reckon- 

 ing tranfverfelj, is flat, without any gradual flope from 

 the fides towards the middle. From the fides the moun- 



fid 



fm 

 Nc 



Ij, and form two continue 



ramparts or embankments 



A sreat nart of the bettor 



valley is occupied by lake 



nam 



Loch 



^fs, Loch Oich, and Loch Lochy. Its length is about 

 lixty-two miles, and the point of partition from which 



the waters run different ways, viz. north-eall to the 



German 



