Kinahan — On Granite and Metamorphic Rocks. 247 



raised-up portions of the doleryte sheets. Associated with the 

 trachyte and nevadyte (the latter locally known as Tardree por- 

 phyry and Tardree granite) are some tuffose rocks, looking very 

 like the Brohlthal of Germany, which, when manufactured into a 

 cement, is called Trass, and is extensively used in the embank- 

 ments in Holland. Whether the German and Antrim deposits 

 are similar as to composition, has, however, still to be proved. 

 Up to the present time the latter has been considered to be 

 useless. 



The Tardree volcanic outburst is probably one of the latest of 

 those in the north-east of Ireland, the trachytic rocks bursting up 

 through the basaltic sheets, and throwing up a small cone, partly 

 lava and partly tuff, to be afterwards more or less modified by 

 marine and atmospheric agencies. 



In Belfast, in the Post Office and Water Commissioners Office, 

 Bessbrook granite, Co. Armagh, was used ; in the Bank of Ireland, 

 Donegall-street, Newry granite ; shops in Ann-street, capitals and 

 columns, Goraghwood granite ; and Queen' 's Bridge, Castle wellan, 

 Co. Down, granite. 



The Eglinton Chemical Company have lately opened quarries 

 in the basalt at Bookis and at Ballintoij, between the Giant's 

 Causeway and Ballycastle. They are sending into the market 

 paving-setts 4" x 4" x 4", 6" x 5" x 3", 5" to 7" x 6" x 3" to 3±", 

 7" to 10" x 7" x 3|" to 4", 9" x 7"-x 41", 6" x 4" x 4", and all 

 sorts of crossings, channels, kerbs, &c, with waste for macadami- 

 zation. 



The harder varieties of the doleryte and the " clinkstone," or 

 basalt that has a metallic ring are generally used in the basaltic 

 area for building purposes, as they can be raised in well-shaped 

 blocks of various scantlings, and will scabble easily. " Whenever 

 it occurs, tabular, massive, or columnar, it makes a very good stone 

 for rubble work. It hammers fairly well, and is most durable ; it 

 is not used for cut-stone purposes, because it is so difficult to work, 

 and has a very dark, forbidding colour." ( W. Gray.) 



"At and near Ballymoney and Coleraine it is of a better 

 working quality than in the south of the county, where it is 

 harder, and has sometimes been used for moulded work." ( Wil- 

 kinson.) 



" The nevadyte or Tardree granite is procured from a quarry 



