During the time of Richard, King of the Romans and Earl of Cornwall, the revenue of the tin mines yielded an immense return; at which time many Jews appear to have been employed in working them. Notwithstanding this success, the latter were banished from the kingdom in the 18th year of the reign of Edward I., when the mines again became much neglected. Shortly after a charter was granted (through Edmund, Earl of Cornwall) to the gentlemen of Blackmoor, proprietors of the Seven Tithings, affording the greatest quantities of tin; by which charter, more explicit grants of the privileges of keeping a court of judicature, holding pleas of action, managing and deciding all stannary causes, of holding parliaments at their discretion, and of receiving as their own due and proportion, the toll tin, or one-fifteenth of all tin raised, were defined. At the same time, the right of bounding or dividing tin grounds into separate portions, for the encouragement of searching, appears to have been regulated; by which the labouring tinner, who might discover tin in waste or uncultivated lands, became entitled to a certain interest in the land, upon giving proper notice in the Stannary Court to the proprietor thereof. The bounds limited the particular portions of ground to which the claim was made, and were formed by digging a small pit at each angle, so that a line drawn from each, determined the extent of the claim. This practise still exists, and the bounder is obliged to renew the pits every year, by removing any dust or rubbish that might otherwise hide his land marks. Carew says, that “this charter had a seal affixed to it, with a pick axe and shovel in saltier.” In consideration of the privileges granted by this charter, the gentlemen tinners undertook to pay to Edmund and his successors, Earls of Cornwall, the sum of 4s. for every hundred weight of white tin. To secure the payment of that tax, they agreed that all tin should be brought to places appointed by the Prince, and there weighed, coined, and kept till the duties were paid. In the 33rd of Edward I., this charter was confirmed, and the tinners of Cornwall were made a distinct body from those of Devonshire, having before been accustomed to assemble on Hengston Hill, every seventh or eighth year, to arrange their concerns and property in the mines. The laws and privileges of the Cornish miners were further enlarged in the 15th year of the reign of Edward III., and subsequent acts passed in the reigns of Richard II., and Edward IV., which confirmed the previous privileges, and the tinners divided into four bodies, and placed under the superintendance of one Warden, reserving them an appeal from his decisions, in suits of law and equity to the Duke of Cornwall in council, or should the title be held in abeyance, then to the Crown.