152 Mr. Taylor's description of the 



I give the provincial names of the rocks as they are in general 

 use among the Cornish miners. 



A — 311 fathoms Killas 



B — 11 Elvane Chlorite and Quartz 



C — 23 Killas 



D — 6 Grouan Clay Porphyry 



E _ 12 Killas 



F — 26 Grouan Clay Porphyry 



G — \ Killas 



H 7 V436 C Ditto 



13 ) C Ditto, with veins of Quartz 



K — 15 Elvane 



L — 3 Killas 



M — 7 Grouan Porphyry 



N — 12 Elvane Quartz, granular and crystalline 



O _ 408 Killas 



1270. Whole length of the tunnel. 



The direction of all these beds seems to be parallel, and to range 

 nearly east and west. 



All the veins that at present are known in the part of the hill 

 which the tunnel will intersect are shewn in the drawing, by lines, 

 which describe their dip as nearly as is ascertained from the little 

 that has as yet been seen of most of them. 



Some of these lodes have been discovered by the tunnel, and 

 some are known by old works upon them near the surface. 



It was not to be expected that any great proportion of the num- 

 ber would turn out productive of ore, or at least that they should 

 be so at the exact point where the tunnel cut them. One or two, 

 if rich in ore, might render the speculation a profitable one, and it 

 is rather extraordinary that the first which was discovered, at the 



