Os], 
very inconfiderable, and not antient j and indeed the 
fides of the cliffs, and the ftrata of bare rocks, do not 
fhew, that ever there have been any confiderable 
workings there for tin, or give us the leaft promifing 
circumstance to encourage tin-adventurers. For among 
fueh numbers of rocks and cliffs, as I pafs'd over in 
St. Mary’s, and the off-iflands, nothing furpriz’d me 
more, than that there fhould be fo few veins in ftrata 
formerly fo famous for tin. In the cliffs of Cornwall 
’tis very different j you cannot walk on any beach, 
without perceiving veins of one fort or other, in the 
clay, rubble, or rock ; but here in Sylley it is gene- 
rally one continued rock, and the interliices fo clofe, 
that fcarce a knife can get between. 
Behdes the load above-mention ’d in Trefcaw, I faw 
a very narrow one in the fame ifland under a place 
call’d Oliver’s battery (marked K) but could perceive 
no metal, either by infpe&ion, or by more than ordi- 
nary weight. I faw two veins, about two inches wide, 
running thro’ the rocks on the back of St.. Mary’s 
pier ; and a gentleman in company thought he had; 
found one in Porthmellyn ( L ) ; and thefe are all we 
could difcover, tho’ our attention this way feldom 
left us. 
There is one place on Dolphin-Downs, in Trefcaw, 
where they work’d for tin in the antient manner, 
which was by laying open the ground in the fame 
way as we now work ftone quarries ; and this is every 
thing I could perceive, in all thefe iflands, which 
look’d like a working for tin. It muff therefore be 
matter of wonder where the Phenicians, Greeks, and 
Romans, could- have found fuch a plenty of that ufeful 
metal. 
