Monument record MDR6704 - Black Hillock Mine, New Farm, Tideswell

Mine shaft reportedly 104 or 120 fathoms deep ( 1 fathom = 6 feet). Now only a large hillock remains adjacent to New farm, the precise location of the main shaft (perhaps 3 by 3 m) is not known, nor is that of its adjacent climbing and ventilation shaft, which, unlike the main shaft is known to have descended in stages. The shaft was designed to search for a western extension of the Tideswell Rake beneath the loadstone, it was unfortunately located on a feeder vent to the Potluck Sill and descends throughout in black dolerite. The shaft was begun in 1757 and was worked again in 1768. The site is also important in that it was used by Whitehead and Fevey in attempting to elucidate geological principles, where they were baffled by the apparent thickness of the loadstone. (1,2).