Mr. Smith on the Stream Works of Pentowan. 405 



seem to direct its course. In some places these approach very near 

 together, in others they widen, and leave a greater expanse of plain. 

 The whole of these levels from within half a mile of St. Austle to 

 the sea having been found rich in deposits of tin, have at various 

 times been turned over, and great quantities of ore have thus been 

 ©btained : they are all at this time enclosed and cultivated. At the 

 mouth of the river the shore is flat on both sides to some distance ; 

 at half a mile to the east begin the high cliffs that extend to Black 

 Bear point. 



The Upper Pentowan work lies about one mile north of the 

 beginning of the sea-beach, and about one mile and a quarter north 

 of the sea, the valley being there about half a mile wide. 



The folloiuing is the section of the Strata which I observed in the 

 Upper Pentowan Stream Work. 



Depth from 

 surface 

 Feet Inches 



Stratum 1. Soil with trees growing thereon 3 3 



2. Deposit of mud mixed with small gravel, waving thus^^^ 20 23 



3. Small grained spar and killas 3 26 



4. Growan (or decomposed granite), spar, killas, &c. similar 



to those which are now found on Hensbarrow and other 

 neighbouring Hills 5 31 



5. Gravel, at the bottom of which are oak trees and branches, 



of great size 5 35 



6. Tin ground 5 41 



7. Clay, in which were the roots of a vast oak tree, which 



seemed to remain in the very position in which it grew. 

 I was told that the trunk had been cut away for fire-wood, 

 and that various trees had been found. Three feet above 

 this level and at no great distance from the root was the 

 end of a branch of oak of great size projecting from the 

 wall of the work. The part visible was about 4 feet long 

 and 3 feet in diameter. It is not improbable that at a 

 greater depth a second mineral deposit may be found, as 

 has been known to occur elsewhere under a bed of clay. 



Vol. iv. 3 f 



