Kinahan — On Irish Marbles and Limestones. 433 



Drumbally. — Very similar to the limestone at Desertmartin, 

 and, as there, the yellowish rocks are hydraulic. 



The limestones from the metamorphic rocks in the Tirkeeran 

 Hills (south and south-west of Dungiven) give a good, strong, dark- 

 coloured lime; while those of Carboniferous and Cretaceous age 

 give purer and clearer products, and also yield a larger return. 



At Desert Martin and Drumbally there are good hydraulic 

 limestones, which were extensively used during the building of the 

 bridges over the Bann, at Coleraine, Portglenone, and Toome. 



Longford. 



Except to the northward, where the older rocks are exposed, 

 this county is principally Carboniferous rocks. They, however, 

 are nearly invariably more or less obscured by surface accumula- 

 tions, such as drift and bog. 



Lisryan. Four miles from Granard. — Dark-grey, earthy, com- 

 pact ; pyritous in places ; principally in layers ; partly shaly. 



Crossrea. Near Granard. — Dark-grey; spotted when polished; 

 coarse ; in part fossiliferous. 



Creices. Three miles from Longford. — Light-grey. In the 

 upper portion the beds are from 2| inches to 3 feet thick, but the 

 lowest bed is over 18 feet thick. From the 2|-inch bed flags 

 30 feet square or more could be procured. From the bottom, 

 blocks 10 feet long and 6 feet wide can be raised. The stone is 

 very highly thought of, and was used in the building of Carrick- 

 glass House. 



Richmond Harbour. Five miles from Longford. — Greyish- 

 blue ; can be raised in very large blocks. Used extensively in the 

 Shannon works at Tarmonbarry. 



Rathcline. Near Lanesborough. — Dark-grey ; compact ; works 

 freely and polishes well. It was used largely in the works on the 

 Shannon in the vicinity of Lanesborough. 



The lime of this county is generally good. 



Louth. 



A very small extent of Carboniferous limestone is found. It 

 occurs in the valley of the Boyne, at Ardee, north and north-east 

 of Dundalk, and near Carlingford. 



Greenore and Carlingford. — Bluish-grey. Extensively quarried 



SCIEN. PROC. E.D.S. — VOL. V. PT. V. 2 G 



