50 



On the west coast of Inishmaan, or the middle 

 island of Arran, the sea-cliffs rise in steps, as they are 

 followed southward from Trawtagh, until at Aillinera 

 they reach their maximum height (nearly 200 feet) ; 

 southward of this they gradually fall to nearly the 

 sea level at Allyhaloo, the S.W. point of the island. 

 Immediately south of Aillinera, at a height of about 

 170 feet, there is a "block beach," which is con- 

 tinuous from this point round the west and south- 

 east sides of the island. 



South of Aillinera the " block beach " is on higher 

 ground than that on which it now occurs on any of 

 the cliffs of Inishmore. The cause for this is not 

 apparent, unless it may be that hereabouts the tides 

 run against the cliffs with greater force than else- 

 where, and thereby the waves may be enabled to hurl 

 the blocks to a greater height. 1 



The sea would appear to act more vigorously on a 

 coast-line that is sinking than on any other ; but, in 

 such a case, it should be remembered that the cliffs 

 or rocks, prior to having been exposed to marine 

 action, had for years, perhaps ages, been subjected 

 to atmospheric influences that loosened and disin- 

 tegrated them, leaving them ready to be easily 

 quarried and carried away. 



The rocks above low water mark, on a coast-line, are 

 daily exposed to atmospheric denudation, and its 



1 " Mem. Geol. Survey, Ireland," ex. sheets 104 and 113. 



