Between 1844 and 1858 the ‘adventurers’ of the Mendip Hills Mining Company sank 6 deep shafts at Charterhouse in search of lead ore, without success. From 1847 to 1885 they reworked almost the whole deposit of lead-rich refuse that had been left by earlier miners in Blackmoor and Velvet Bottom valleys. The venture was beset by disasters and lost money until Nicholas Ennor was employed as a consultant. In 1861 control passed to a large Cornish smelting firm, Treffry’s and thereafter profits were made. Detailed accounts are given of the existing remains of mining and slagging.