C 6 + ] 
metal. Whatever refources they had from Cornwall, 
(formerly reckoned, as I have great reafon to think, 
among the Calliterides) great part of their tin muft 
doubtlefs have come from thefe idands ; but where 
it was found is uncertain. Nothing now appears above- 
ground, which can fatisfy fuch an inquiry. The ftory 
of the Phenician veftel mention’d by Strabo to have 
purpofely run afhore, and rifqu’d the men as well as loft 
the fhip, rather than difcover to the Romans the trade 
to thefe ifles, is well known, and proves beyond all 
doubt the commerce to have been very advantageous. 
That the natives had mines, and work'd them, ap- 
pears from Diodorus Siculus, lib. 5. cb. 2. and from 
Strabo (G'eog. lib. 3.) who informs us, that Publius 
Craflus failing thither, and obferving how they work’d 
their mines, which were not very deep, and that the 
people lov’d peace, and at their leifure navigation, 
inftrudled them how to carry on this trade to bet- 
ter advantage : That is (if I underftand him rightly) 
feeing their mines but fhallow, yet well worth work- 
ing deeper, taught them how to purfue the metal to a 
greater depth. The queftion then is, what is become 
of thefe mines ? And how fhall this queftion be an- 
fwer’d, but by confefiing, that the land, in which 
thefe mines were, is now funk, and bury'd under 
the fea ? 
I am not fond of introducing earthquakes, or call- 
ing in the powerful fubterraneous world to account 
for the iuperficial ; but where there has been evi- 
dently a great fubfidence of the earth’s furface, I am 
very willing to refer to better judges than myfelf, 
whether it . can be accounted for at all, without a 
previous trembling and concuftion of the earth. 
Proofs 
