Jefferson's knowledge of ancient England was clearer than ours, or so it seems.
And I haven't quite bought into the whole "Brits are the lost tribes of Judea" thing yet, even if Celtic and Aramaic mesh so perfectly.
The deposits of tin in the ancient world were usually small and not very plentiful. The Phoenicians discovered the tin deposits of the British Isles through their own exploring and seeking out of new products and markets for them. They kept the knowledge of the Cornish tin mines a closely guarded secret so they could control trade in the metal and charge a high price for it. After the Punic wars, Carthage, the one remaining city of the Phoenicians, became less and less an important economic power. With their well - known efficiency and thoroughness, the Romans counted access to the British tin mines as one of the advantages of conquering the island. Julius Caesar knew of the importance of British tin when he invaded the island in 55 to 54 B.C. After the conquest of Britain during the reign of Claudius, the Romans were in control of most of the world's supply of the metal. Hence, the closely guarded treasure secret of Britain's tin passed hands from the Phoenicians to the Romans.The fact that tin trade existed is too well attested to need proof. Herodotus as early as 445 BC speaks of the British Isles as the Tin Islands or Cassiterides. Pytheas (352-323 BC) mentions the tin trade, as does also Polybius (circa 160). Diodorus Siculus gives a detailed description of the trade. He tells us that the tin was mined, beaten into squares, and carried to an island called Ictis, joined to the mainland at low tide, which is generally held to be Mount St. Michael in Cornwall, although some have identified it with Falmouth. Thence it was shipped to Morlais, and transported across France on pack horses to Marseilles. From Marseilles it was again shipped to Phoenicia. Innumerable ancient workings in Cornwall still attest the trade, and tin is still mined there today. Lord Avebury and Sir John Evans held the opinion that the trade existed as early as 1500 BC, and Sir Edward Creasy in his History of England writes: "The British mines mainly suppled the glorious adornment of Solomon's Temple". This matter ties in very well with the involvement of Phoenician builders with construction of Solomon's Temple.