Whitaker — On Suhaerial Denudation. 451 



There are many points which have already been more or less gone 

 into in detail by others, and therefore need but a passing notice 

 here,^ amongst them are the following : — 



(1.) Escarpments always run along the strike, whilst actual cliffs 

 rarely do so (and then only for a short way), but cut through rocks 

 without regard to it ; whereas if both had been formed by the sea 

 they should be more alike. 



(2.) The bottom of an escarpment does not keep to one level, but 

 rises slowly inland, or towards the watershed, that is in accordance 

 with the drainage-level of the country and without regard to the 

 level of the sea. Professor Eamsay has called my attention to the 

 fact that sometimes the base at one place is higher than the top at 

 another. 



(3.) Sea-cliffs run comparatively straight, or rather in curves of 

 large radius, through homogeneous rocks (of course through a succes- 

 sion of hard and soft beds they have an irregular outline) ; but 

 on the other hand escarpments wind about, which they should not 

 do if they were simply old cliffs. Here the saying, " the exception 

 proves the rule " holds good ; for the wonderfully intricate coast- 

 line of Norway and of other like countries is well known to have 

 been caused by the siaking of the land, and not by the action of the 

 sea, the wearing-power of which is as nothing up the deep narrow- 

 win ding fjords, so clearly seen to be submerged valleys. 



(4.) If escarpments have been formed by the sea, there ought to 

 be at their foot some resultant of that agent, a beach or other 

 marine deposit ; but this is not the case (except, perhaps, in some 

 places where masses of Boulder Drift end near the bottom of a 

 ridge), whatever deposit there is being such as one would look for 

 from subaerial actions. 



(5.) It has been said that any beach which there may once have 

 been at the foot of an escarpment has perhaps been destroyed 

 by subaerial denudation wearing back the ridge. To this it has 

 been answered that such a concession to the power of subaerial 

 action is really much the same as giving up the question at issue in 

 their favour ; for if they are powerful enough to do so much they 

 could surely do more in a longer time. 



(6.) Sometimes two escarpments (facing the same way) run 

 roughly parallel and near together for miles, as those of the Chalk 

 and Lower Greensand in Surrey and Kent, and those of the Chalk 

 and the Portland Stone in part of the Isle of Purbeck. To suppose 

 these formed by the sea implies that there have been two long 

 parallel ridges of land, each consisting of a separate formation, 

 divided by a narrow strip of sea, the like of which is not to 

 be seen now-a-days. Moreover, the sea would have little power 

 to act in so narrow and sheltered a place, but would be as harm- 



1 It would be overburdening this paper with foot-notes were I to acknowledge the 

 many sources whence some of the following arguments have been in great pait 

 derived ; enough to refer the reader to the list of authors given before. I would 

 gladly have quoted largely from Hutton, Playfair, Scrope, and others, but the paper 

 would have been much lengthened thereby. 



