146 Scientific Proceedings, Royal Dublin Society. 



it would be also of great benefit to the quarries to clear away 

 the heaps that are now so much in the way, and cause such 

 additional expense. There would be every facility for such a trade 

 in connexion with the slate workings in the vicinity of the Suir, 

 to the westward of Waterford, as fuel could be brought and the 

 brick sent away in boats. 



Many of the Irish facing bricks are panelled, and a few like 

 those of Castle Espie, Co. Down, and Courtown, Co. Wexford, are 

 perforated. Perforated bricks cost less for carriage, but are not as 

 lasting in face-work as the solid brick, damp and frost making 

 their way into the perforations, thus making the bricks liable to 

 moulder away. 



The prices of bricks, especially in the country places, change so 

 rapidly, according to the time of year and demand, that it is 

 impossible to give them accurately. Even in Dublin at one time 

 they may be much higher or lower than they were a few months 

 previously ; we have tried to give a fair average ; our estimate, 

 however, may be, for some places, too low. 



ANTRIM. 



Ai/umite, or Alum Clay. — This occurs as one of the members 

 of the Iron Ore-measures in the Tertiary Dolerites. It has 

 been already mentioned and described in the first Paper of the 

 series on Irish Metal Mining (vol. v., pp. 251 and 261). 



Diatomite, or Diatomaceous Clay. — The only Irish localities 

 for this clay at present known are those in the Cos. Antrim and 

 Down in the alluvium of the Bann Yalley, to the northward of 

 Lough Beg ; it being locally known as " Bann Clay." 



Bann Clay occurs on the north of Lough Beg, where it is mixed 

 with grey stiff clay for the manufacture of bricks. Between 

 Lough Beg and Portglenone it is from four to five feet deep, and 

 is applied to similar purposes. At Annaghcrew, north of Port- 

 glenone, it is only one foot thick ; but further northward, south of 

 Portna, it 'has increased to two feet. Still further northward it is 

 again found along the narrow flat north of Kilrea, and can be 

 traced as far north as Ballynacree House. At New Row, where 

 there are brick works, it is four feet thick, and lies on five feet of 

 peaty clay — (g. s. m.). This clay is brownish-grey in colour, 

 weathering white. It is nearly pure silica, being made up almost 



