178 THE RIVER VALLEYS OF 



ridges, and form the transverse river valleys ; as, for 

 instance, the sea is at present working across the 

 neck of land that separates Dunmanus and Schull Har- 

 bours, and across that between the north and south har- 

 bours on Cape Clear Island. If river action is appealed 

 to as having formed these parallel transverse ravines, 

 where did the water come from that cut the passes, 

 mentioned in a former chapter, through the headland 

 and mountain ridge south of Ballydonegan Bay? To 

 get a water-supply, it would be necessary that the 

 bay should have been once high land ; and if so, 

 what has become of this ? Eain and rivers could not 

 have denuded it away, and as " the internal forces 

 of disturbance had ceased," it could not have sunk. 

 As from ocular demonstration it would appear that 

 the sea of the present day is excavating transverse 

 valleys along breaks in the rocks, and as most 

 of the transverse valleys in South-west Cork have 

 been proved to lie along breaks, it seems un- 

 reasonable to say that marine action, or "the 

 internal forces of disturbance," could have had 

 nothing to do with the formation of the tranverse 

 valleys across the inland ridges. 



The sea may act very unequally, as we have 

 said, along the bedding, cutting long bays into soft 

 beds ; but when it works perpendicularly, or nearly 

 so, to the strike of the beds, it may denude more or 

 less regularly, wearing away bed after bed. On 



