556 Scientific Proceedings, Royal Dublin Society. 



rivers ; while near Kilkeel and Newry the sea sand is also good. 

 Red sand suitable for foundry purposes, and exported from Belfast 

 to Dublin, Cork, &c, is procured in the valley of the Lagan. 



Flint-Glass was formerly largely manufactured in Newry. 

 Although this was in existence in 1840, yet now it seems hard to 

 get information about it. 



There was a second manufactory at Ballymacarret, a suburb of 

 Belfast. To this, at the beginning of the century, a few cargoes 

 of Muckish sand — Ards, Co. Donegal — was brought, and found to- 

 be very superior; but the expense of getting the sand, and the. 

 consequent high price when delivered, drove it out of the market. 



DUBLIN.* 



There are arenaceous rocks among the Ordovicians to the north 

 and south-west of the county, the latter in part being metamor- 

 phosed. In the Eathmichael Round Tower, quartz-rock and clay- 

 slate were used ; but the masonry is very rude. As beds of limited 

 thickness in the calp division of the Carboniferous there are argil- 

 laceous sandstones, and there are also sandstones in the Lower Coal- 

 measures. 



Carboniferous. — In some of the calp quarries there are ar- 

 gillaceous calcareous sandstones, or arenaceous limestones, capable 

 of being raised in large blocks, and suitable for heavy work, such as 

 foundations, for which they have been extensively used. In some 

 quarries they are thin-bedded, and give good flags. This was 

 specially the case in one set of beds in the old " Windmill 

 Quarry," Rathgar, and some years ago there was an extensive- 

 trade in them. As, however, the " overbaring," and conse- 

 quently the expenses of the quarry, increased, the trade dropped. 



In the north division of the county there are patches of Lower 

 Coal-measure rocks. In these there are some grits and sandstones ; 

 but although some of them are fair stones, none of them appear to 

 have been used, except for local purposes. 



In the city of Dublin sandstone is largely displayed in the 

 public buildings ; but none of the cut stone seems to have been 

 obtained in the county, while most of it, especially in the buildings 

 during the last century, and in the beginning of the present, is* 



* See " Notes added in the Press." 



