Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/358

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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.[1] 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

  1. Plate 18.