The Mucrus Mine was worked for about five years (from 1749 to 1754) to great advantage; the depth was then thirty-six fathoms, but the part of the vein within reach of the first shaft having become too narrow to pay for the expense of a second, it was determined to sink some distance to the east in the direction of the vein, which was thus recovered at the depth of from seventeen to twenty fathoms. It yielded yellow copper ore, and was five feet wide; the ore however being too sulphureous it was abandoned, though the original shaft had brought in £30,000, and was so easily drained that a common windlass kept it dry. The cobalt being totally unknown, except to a single adventurer (who on one occasion took away about twenty tons) was neglected, and landed only as rubbish, till a more experienced miner, since dead, at last pointed out its nature and value. From that time people visiting the mine have carried off specimen after specimen, so that the original profusion would now be doubtful, were not these circumstances recollected by most persons then resident in the neighbourhood. The ore has a granulated and metallic appearance; it has the hardness of stone; its colour is dark blue, tending to a beautiful pink. A mass of about a quarter of a hundred weight had the appearance of being found within the copper of vein; but this was only conjecture, for in whatever quantity it might then have been encountered