90 Scientific Proceedings, Royal Dublin Society. 



Forest House. The slate is of a greenish colour, and very good, but 

 heavy. It has been extensively used for the roofing of the neigh- 

 bouring mansions, farm-houses, and buildings. The slate has 

 been tried again of late years, but only a narrow portion of the 

 vein formerly worked was found capable of producing slates light 

 enough for the present market. To the south of the quarry there 

 is a vein of good appearance not as yet tried. 



About seven miles or so N.N. E. of Killaloe are the quarries 

 called after that town. 



Killaloe Slate Quarry. — The quarry to which this name is now 

 almost solely applied is at Corbally, near the village of Portroe. 

 In the vein there appears to be here a nearly inexhaustible supply 

 of excellent slate ; but the quarry was badly laid out originally, 

 and is too confined to be worked to the best advantage ; and a 

 great deal that ought to be profit is spent in raising the slate, 

 rubbish, and water out of the quarry, which is large and deep. 



This quarry was first opened, about the year 1826, by the 

 Mining Company of Ireland, who worked it till about 1841, when 

 it was bought by the Imperial Mining Company, who were work- 

 ing quarries in the vicinity. Besides roofing slates, the latter 

 Company manufactured slabs for flooring, steps, window-sills, &c. 

 Under these Companies the quarry does not appear to have been 

 very profitable. It eventually, however, fell into the hands of Mr. 

 Headach, who was very successful, and in the end sold it to the 

 Killaloe Slate Company, who are now working it. There is a 

 ready sale for all the slates that can be made, but, unfortunately, on 

 account of the peculiar contracted condition of the quarry, the 

 output is much less than it ought to be. 



To put the quarry into a condition so that it could be worked 

 to the best advantage would require a considerable immediate out- 

 lay ; but this would be vastly more than compensated for hereafter 

 by the saving of working expenses and the much larger annual 

 sales. 



The width of the slate vein is over 400 feet. It is divided into 

 sub-veins, some with a ribbon (cleaved shale), and some without 

 [cleaved clay-rock) , which average in width from fifteen to twenty 

 feet. The latter are the more profitable, as they split more easily ; 

 besides which they have horizontal joints (soles), which facilitate 

 the working of the veins. The soles are greatly prized by the 



