Mr. William Phillips on the Veins i)f Cornwall, 133 



IS under the necessity of passing in the usual course of his occupa* 

 tion in the sinking of shafts and driving of levels and adits, often 

 prove the occasions of great hindrance and loss. There is a narrow 

 channel of a remarkably fine grained substance consisting of compact 

 felspar and chlorite, running in the direction of east and west, a little 

 north-west of Redruth, which is so exceedingly hard as to have ob- 

 tained the technical name of Ire-stone or Iron-stone. It was met 

 with in driving an adit towards a mine, the Old Pool, I believe 

 and it has often been told me, that it was so remarkably compact in 

 one place as immediately to turn the point or edge of every tool, 

 so that it was found impossible to drive a hole deep enough to em- 

 ploy the blast by gun-powder: the miner was compelled little by 

 little to pick through that part of it, in doing which the seat-board 

 -was not once moved forward during the space of 12 months. 



The schist of Cornwall varies much in colour as well as in 

 hardness. It passes from lightish grey through the shades of slate 

 <;olour to that inclining to a reddish hue, which is considered to be 

 promising as to the occurrence of tin. But that which is esteemed 

 the most kindly both for copper and tin, as well as the least expensive 

 in the working, is of a light grey colour inclining to slate. This 

 Jcind of schist is easily broken, and may be left without much sup- 

 jport, and is therefore what the miner terms feasible ground^ but it 

 coften passes in depth into a far more £ompact kind, of ii dark colour, 

 inclining to blue. 



Crosi or North and South Veins* 



It has already been noticed that there are veins in Cornwall, 

 which as they are found almost uniformly to traverse the east and 



