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



that they have been wasted by time ; since that time which has 

 diminished the hardest should have obliterated the softest. If we 

 examine their profiles (of which numerous representations are here 

 given) we shall also see that they bear no resemblance to a work of 

 art. There is no inferior talus, nor, except in one solitary instance 

 which I have noticed, is there any mark of a superior one. They 

 are stairs, if I may use such a comparison, on the face of the hill. 

 It may be answered that the natural decay of the road would consist 

 in the sliding down of the upper talus into the road, so as gradually 

 to diminish its slope and to fill the interior angle, while a similar 

 waste of the lower one would round the exterior or salient angle. 

 But if we examine the final result of this double waste, we shall see 

 that when this ultimate ratio of equality is established throughout the 

 upper and lower talus and the natural slope of the hill, the road must 

 disappear altogether, instead of maintaining, as it often does, a breadth 

 of 70 feet upon an uniform slope of the face of the hill. There is 

 another circumstance in their construction equally repugnant to this 

 hypothesis. In no one instance is the surface level, or even nearly 

 so, as the profiles will show.* The least angle which I discovered 

 was one of 12° with the horizon, and more generally they vary from 

 20° to 30°. This is an effect which could not readily have taken 

 place had they been originally level, as the permanent regularity of 

 their surfaces shows that they have undergone very inconsiderable 

 changes since their first formation. 



Their capricious arrangement, if considered as works of art, is 

 equally an objection to the notion of their having been intended as 

 roads. Numerous and crowded in some places they are totally absent 

 in others, and that even where no wasting causes appear to have 

 existed. It may be added perhaps to these objections, that the 



* Plate 18. 



