338 Dr. Mac Culloch on the Parallel Roads of Glen Roy. 



in no instance did I perceive the marks of an inferior one. But 

 the profiles now referred to, which were selected among the most 

 remarkable ones, will represent these several circumstances better 

 than they can be described by words. 



With regard to their structure I can only say, that it does not 

 appear to me calculated to throw light upon any system respecting 

 their origin. When they are found on those faces of hills where 

 the rubbish is sharp, they consist of sharp materials j where it con- 

 sists of transported materials, they are formed of rounded gravel 

 and sand. Whatever hypothesis of their formation may be adopted, 

 it is evident that this circumstance can throw no light on it ; as, 

 whether they are the effects of nature or of art, they must have 

 been formed in and of the materials in which they exist. 



Having thus described Glen Roy itself with the lines for which 

 it is distinguished, and pursued its connection with the neighbouring 

 vallies, it is necessary to extend our views, and to trace its connec- 

 tion with the sea. 



The glen itself opens by a wide mouth, as I before said, into the 

 great valley which stretches between the northern and western sea, 

 and which is the seat of the Caledonian canal. This opening is so 

 gradual that its breadth cannot be defined, but it may be conceived 

 to vary from five to seven miles. The whole of this space is uneven 

 and hilly, consisting of rocky elevations and alluvial deposits. The 

 Spean flowing through it and falling into the Lochy forms one deep 

 section, but no other water courses are found in it, either direct or 

 lateral ; such at least as exist are of very insignificant dimensions. 

 On applying the spirit level to a great many points through this 

 wide space they were all found inferior to the lowest line of Glen 

 Roy, with one or two trifling exceptions. The opening of Glen 



