A Vice Warden is appointed by the Lord Warden, to determine all stannary disputes; he also constitutes four Stewards, (one for each precinct) who hold a Stannary Court every three weeks, and decide by juries of six persons, with a right of progressive appeal to the Vice Warden, Lord Warden, and the Lords of the Prince’s Council. The original Stannary Towns were Launceston, Lostwithiel, Truro, and Helston; to these places the miners were obliged to bring their tin every quarter of a year. But in the time of Charles II., Penzance was added for the convenience of the western tinners. All tin ores are wrought into metal in the county, and are afterwards cast into blocks, weighing from 2½ cwt. to upwards of 3 cwt. each. They cannot be disposed of till assayed by the proper officers, and stamped with the Duchy seal, which bears the arms of Richard, Earl of Cornwall, viz. a lion rampant, gules, crowned or, with a border sable garnished with bezants. Since the reign of Henry VIII. the coinages have been held quarterly. The average annual produce of the tin mines is about 25,000 blocks, which, exclusive of duties, may be valued at £260,000, and yielding a revenue to the Duchy of Cornwall of about £10,000 annually. The most considerable tin mines now working, are in the neighbourhood of St. Austell, St. Agnes, and Piranzabuloe. The celebrated _Polgooth Mine_, near the former place, however, has not been worked for upwards of 20 years past. There are also many other valuable tin mines in the western districts, north-west of Truro. Besides the mines, there are several stream works in the county, which have yielded immense quantities of tin.