542 Scientific Proceedings, Royal Dublin Society. 



CORK. 



In this county sandstones and grits are the principal rocks, 

 they being of Silurian, Devonian, and Carboniferous ages. (See note 

 on Old Red Sandstone, under Kerry, page 568.) 



Silurian and Devonian. — The rocks of the hill country to the 

 north and west of the area nearly all belong to one of these divi- 

 sions, Carboniferous rocks only being found in portions of the valley. 

 The Silurians [Glengariff grits) and Devonians [Lower Old Red 

 Sandstones) are locally called "brown stone" and "red stone," 

 while the Carboniferous sandstones {Yellow sandstones and Coomhoola 

 grits) are known as " grey stone." 



In numerous places in the Silurian and Devonian excellent 

 and durable stones for tool-work could be procured, as is exhibited 

 in the various ancient buildings, Limestone, however, is now 

 generally used for dressings and other cut-stone purposes. This, 

 in a great measure, seems to be due to the architects and workmen, 

 who have learned and live in the cities where limestone is used, 

 objecting now to use the sandstone ; the workmen especially, as 

 sandstones are much harder on their tools than limestones. Lime- 

 stone, however, in early times, in places superseded the sandstone, 

 as at Cloyne, where the sandstone in the Round Tower was pro- 

 cured between its site and the shore ; while the other ancient 

 structures, but more recently built, are of limestone brought from 

 a distance. 



The Hound Tower of Cloyne, just mentioned, displays the 

 excellent qualities and durability of the stone of the neighbour- 

 hood. It is of a light, brownish- coloured sandstone, the work 

 being good, especially round the doorway. Of the work Wilkinson 

 states that the stones are notched one into the other in a peculiar 

 manner ; also that their state of preservation shows the durability 

 and sound quality of the material. 



From the list given (page 545) and descriptions, for which I 

 am indebted to Mr. Williams of the Board of Works, it would 

 appear that some of the South-west Cork sandstones are well 

 worthy of more attention than they now receive. 



Sherkin Island, off Baltimore Harbour. — The stone, when first 

 raised, is greyish ; then it becomes tinged with green, probably 



