Ventilation flue built in 1860. Fragment of datestone which appears to have read (BHIO CO/MDX)XXLX found at bottom of stack in 1960. A recess in the stack from which the datestone may have fell can be seen half way up the south side of the stack. It is possible the adjoining air shaft was first sunk by Sir Thomas Lethbridge in 1840 as adit number one appears to have been driven outward from the shaft bottom. [1] The chimney was subject to a condition survey in March 2002. It was noted to be suffering from serious weather erosion of the mortar with the more pronounced wear occurring on the weather side, with a pronounced lean on this side. [2] Tall circular masonry chimney with surviving fire hearth. Surviving sections of air duct at ground level, which linked the chimney to the adit below. Upper part of chimney is missing and the surviving masonry is weathered and in need of repair. [3] The Scheduled Monument Condition Assessment of 2009 gave the site a survival score of 8. [5] The site was surveyed in July 2015 as part of the 2015 Exmoor Scheduled Monument Condition Assessment. It was given a survival score of 8. [6]