146 ' Mr William Phillips on the Veins of Cornwall. 



apart from its reasonings and its philosophy, a valuable production. 

 I have not thought it necessary to acknowledge my obligations to it 

 in every particular instance ; nor, on the other hand, have I been 

 willing to quote its authority, without verifying it by an appeal to 

 some of my numerous friends among practical miners. 



As an appendix, it seemed to me that some account of the veins 

 of certain mines, remarkable either for their peculiarities or some 

 striking geological fact, might therefore be an acceptable addition 

 to the geologist, as well as in corroboration of what has preceded. 

 I have however to express my regret that these relations are imper- 

 fect, inasmuch as little is said on the subject of the countries in which 

 these mines lie. For as the information on that head could only be 

 obtained from the practical miner ; and as he notices the country 

 merely as respects the ease or difficulty with which his operations 

 are carried forward, or at most no further than regards his three 

 grand distinctions of grouan, killas, and elvan, little or nothing 

 satisfactory could be obtained, on that important part of their his- 

 tory. 



Ground Plan of Herland and Drannack and Prince George 



Copper Mines* 



Pi. 8. fig. 9. 



Herland and Drannack mines are situated in a hill that rises sud- 

 denly on the west for some distance, but which is afterwards nearly 

 on a level for about half a mile, the highest ground being about 

 the center of that vein termed the Manor Old Load, having a gra- 

 dual fall to the south of the middle mine. The country is schist, 

 but in some places so hard as to require the blast by gun-powder. 



