Dr. Mac Culloch on the Parallel Roads of Glen Roy. S55 



stood at a considerable height above the present level of Loch Spey, 

 the seat of the supposed elevation. Yet the first line is found within 

 a few hundred yards from this spot, and at an elevation so little 

 above it that it must necessarily have been buried far under the 

 imagined wave ; which could not produce this effect on a surface 

 immersed deeply under it, since the universal pressure of the fluid 

 would produce an equilibrium of actions : nay the very hypo- 

 thesis supposes them to have been formed by the deposit of loose 

 matters at the surface of a fluid in motion. If the assumed causes 

 which this hypothesis requires are, even with all the simplification 

 and assistance which can be given to them, scarcely reconcileable 

 to the appearances of the country and the ordinary course of 

 Nature, the difficulties become insurmountable when we recollect 

 that it is requisite to adopt a series of such causes ; a succession of 

 three similar elevations at given distances of time, producing simi- 

 lar and equal effects under an inequality of circumstances so obvious 

 as scarcely to require mention to those who have reflected on the 

 appearances described in the first part of this paper. Although a 

 more general and distant origin for the supposed diluvian wave 

 should be assumed, the hypothesis is still subject to the difficulties 

 now enumerated ; since the obstruction to its course, formed by the 

 elevated ground which confines Loch Spey, would equally prevent it 

 from exerting the requisite actions on the parts beyond that obstacle. 

 It may appear unnecessary to adduce further arguments against 

 this hypothesis, but as one of the objects of this paper is to point 

 out the circumstances applicable to other enquiries of this nature, 

 should such occur hereafter, it will not be useless to enumerate the 

 remainder. Different cases may require different modes of inves- 

 tigation, and that argument which is sufficient for the present may 

 not be universally applicable, as the peculiar objection here ex- 



