592 Slate Quarries. 



niog district in January 1872 was about S^O. 1 There 

 are also slate quarries in South Wales, but few of them 

 have been worked to much advantage, and in Cumber- 

 land, where slates are or have been worked in the green 

 slates of the volcanic rocks of the Lower Silurian 

 series. The material composing these slates is simply 

 very fine volcanic dust, hardened by intense pressure, and 

 rendered fissile by slaty cleavage. 



In Scotland, in the small island of Easdale, in the 

 Firth of Lorn, there are slate quarries that have been 

 worked for many years, which produce a good, coarse- 

 grained slate, but they are of small importance compared 

 with the immense quarries of North Wales. It is pro- 

 bably not an over-estimate to say that about 15,000 men 

 are employed in the slate quarries of Britain, involving, 

 perhaps, the direct support of about 50,000 people. 



So steady is the profit sometimes derived from slate 

 quarries, that every here and there in North Wales, 

 where the rocks are more or less cleaved, speculators go 

 to work, and opening part of a hill-side, find a quantity 

 of rotten stuff, or of slate full of iron pyrites, or cut up 

 by small joints, or imperfectly cleaved; and after a 

 time, when money runs short, they sell the property to 

 other speculators, who sometimes ruin themselves in 

 turn. 



In various districts of Great Britain the rocks 

 abound in the ores of certain metals, which, generally 

 occurring in hilly regions, the workers in these mines are 

 rarely congregated in great crowds like the slate 

 quarriers of North Wales, or the miners of coal and 

 iron. I will first allude to the case in which the 

 mineral wealth is derived from what are termed lodes, or 



1 This fact was supplied to me by the kindness of Mrs. Percival 

 of Bodawen. 



