206 Scientific Proceedings, Royal Dublin Society. 



thus suggesting that the granite and elvan are of a later age than 

 the Ordovician. 



A long, narrow breadth of the S.E. marginal part of the great 

 Leinster granite exposure lies within this portion of the Co. Wex- 

 ford. In the schists outside of the margin, and running somewhat 

 parallel thereto, there are a few courses of generally finer and more 

 compact granite. In these there is a structure rudely parallel to 

 their walls, giving them a bedded aspect ; while in some of them, 

 conforming to this simulated bedding, there are thick courses of 

 quartz-rock, in some places of blackish or smoky colour. These 

 quartz-rocks seem to be allied to those near Hacketstown, Co. 

 Carlow. 



All over the granite-ground, as also on the margining mica- 

 schist, numerous surface-blocks abound, they being very conspi- 

 cuous in the valley of the Eiver Clody, to the N.E. of the summit 

 of Mount Leinster. On this account no quarry has been opened 

 in the main mass of the granite ; but the courses in the schists are 

 quarried at several places, to supply materials for walling and for 

 road-mending ; while for cut-stone purposes the large loose granite 

 blocks are preferred. At Gorey the Norman columns and other 

 dressed work of the cathedral were formed from them. The rock 

 is generally more or less even-grained, similar to the Co. Carlow 

 stone, except on the slopes of Blackstairs and White Mountains, 

 where it is porphyritic with white crystals of orthoclase. This 

 bright grey porphyritic rock would be very effective for orna- 

 mental purposes ; but we could not learn that it has ever been so 

 utilized. 



[The inhabitants of the country near Blackstairs and White Mountains seem to be 

 generally stonecutters and smiths, each having a little smithy attached to his cabin 

 to repair and sharpen his tools. Formerly these people did a good trade, partly in cut- 

 stone, but principally in gate-posts, farm-rollers, cider-presses, and paving-setts ; large 

 quantities of the last used to be sent to Waterford, New Eoss, "Wexford, Enniscorthy, 

 and other small towns.] 



Whinstones, Eurytes, Felstones, Tuffs, Elvans (Eoot Eocks, 



or Laccolites) . 



Crossing the Co. Wexford obliquely in a N.E. and S.W. 

 direction, and extending into the Co. Waterford, there are more or 



