The tin-ore has always been smelted in the county. Sir Francis Godolphin introduced some improved methods of stamping and dressing tin from the continent; and Sir Beville Grenville made an attempt to smelt the tin with pitcoal; but it was not till the early part of the last century that the present mode of smelting was adopted. Mr. Lyddell obtained a patent in the year 1705 for smelting tin in iron furnaces, and set up works at Angarrack in the parish of Phillack.

[via http://www.british-history.ac.uk/magna-britannia/vol3/cxciv-ccxvi]