Kin ah an — On Granite and Metamorphic Rocks. 239 



In Inishowen these flaggy whinstones are not uncommon, and 

 have been quarried in different places : those best known are as 

 follows : — 



Dunmore. Six miles from Carndonagh, in the Culdaff direc- 

 tion. — Can be raised in blocks and slabs from 6 to 12 feet long ; 

 capable of long and heavy bearings ; cuts any way, but the blocks 

 more generally sawn ; polishes well; of a good green colour ; used 

 extensively in the Poorhouse aud other buildings at Carndonagh ; 

 also for tombstones. {George Baggs.) 



Croagh. Seven miles from Carndonagh, and five from 

 Moville. — A very similar stone to that at Dunmore ; but does not 

 weather as evenly. [George Baggs.) 



Dunree. Close to the Fort where, as well as in the Light- 

 house, it was used for flagging, window-sills, &c. ; a very similar 

 stone to that at Dunmore. The greater part of the Fort is built 

 of a kind of quartzite, which dresses fairly well ; this was raised in 

 the immediate vicinity from a vein in the Ordnance ground. 



Some of the Donegalytes and other whinstones, especially the 

 dykes associated with the bedded sheets in the Kilgarvan (Rath- 

 mullen) district, seem suitable for paving-setts, channels, and 

 kerbs. None of these stones, however, have been tested. 



Metamorphic Whinstone. 

 (Hornblendyte, Hornblende-rock, and Hornblendic Gneiss.) 



The principal zones in which the hornblendic-rocks occur are 

 those northward and southward of the tract of gneiss and granite ; 

 they occur, however, in other places also, but principally where the 

 associated rocks are more altered than usual, as in the Lough 

 Derg district, in the south-eastern part of the county. As in 

 other regions, so here also a common characteristic of the courses 

 is a rib of hornblende-rock or gneiss in the middle, margined on 

 each side with hornblendic-schist (hornblendyte). But some of the 

 masses of whinstone, especially when in or close to the gneiss, have 

 been completely changed into hornblendyte. 



Many of the hornblendytes are capable of being raised in more 

 or less shapely, flaggy masses; but in general they work rough 

 across the foliation, or plane of the flag. Most of the hornblende- 



