104 Scientific Proceedings, Royal Dublin Society. 



appear to be much used, as they are nearly always associated 

 with thin-bedded, nicely- jointed sandstones. 



TIPPERARY. 



Slate rocks occur in the Ordovician and in the marginal Lower 

 Carboniferous strata of this county, and also in the Coal-measures 

 as shales. 



The slate rocks are not very generally used for building, on 

 account of the proximity of the limestone or sandstone, which are 

 often more suitable for that purpose ; but some of them can be 

 wrought into good slates [ante, p. 88). 



TYRONE. 



In the northern part of the county there are slate rocks more or 

 less metamorphosed into schists, in the strata which are probably 

 the equivalents of the Ordovician, Arenig, and possibly Cambrian. 

 Near Pomeroy they also occur in a small tract of Llandovery (?) 

 and in Silurian, that extend from Pomeroy westward into the 

 county Fermanagh. 



In the metamorphic area, especially in the neighbourhood of 

 Strabane and Castlederg, the slates and schists are largely used for 

 common building purposes. In the Lower Carboniferous, the Calp, 

 and the Coal-measures there are shales used for local purposes. 



WATERFORD. 



The slate rocks of the Ordovician, Devonian, and Carboniferous 

 districts of this county are used for walling purposes, the dressings 

 being limestone, sandstone, or granite. Near Waterf ord very gritty 

 slates, already described among the sandstones {vide, p. 611, vol. v.), 

 are quarried at Grange Hill, south of the river ; while north of the 

 river more argillaceous rocks are also quarried for walling and 

 general building purposes. The stones in the north quarry can be 



